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llvm-project/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
Ben Shi 2e43eea2da [RISCV] Optimize multiplication with immediates 
The optimization of (mul x, c) to (ADD (SLLI x, i0), (SLLI x, i1))
is only enabled for i32 multiplication on rv64, because of
the regression in i64 multiplication on rv32.

However we can change the condition to that the immediate 'c'
should only be used once, then the above regression can also be
avoided, and ohter chances of optimization can be enabled.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D147410
2023-04-15 17:29:06 +08:00

15603 lines
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//===-- RISCVISelLowering.cpp - RISC-V DAG Lowering Implementation -------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the interfaces that RISC-V uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//
#include "RISCVISelLowering.h"
#include "MCTargetDesc/RISCVMatInt.h"
#include "RISCV.h"
#include "RISCVMachineFunctionInfo.h"
#include "RISCVRegisterInfo.h"
#include "RISCVSubtarget.h"
#include "RISCVTargetMachine.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/VectorUtils.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicsRISCV.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include <optional>
using namespace llvm;
#define DEBUG_TYPE "riscv-lower"
STATISTIC(NumTailCalls, "Number of tail calls");
static cl::opt<unsigned> ExtensionMaxWebSize(
DEBUG_TYPE "-ext-max-web-size", cl::Hidden,
cl::desc("Give the maximum size (in number of nodes) of the web of "
"instructions that we will consider for VW expansion"),
cl::init(18));
static cl::opt<bool>
AllowSplatInVW_W(DEBUG_TYPE "-form-vw-w-with-splat", cl::Hidden,
cl::desc("Allow the formation of VW_W operations (e.g., "
"VWADD_W) with splat constants"),
cl::init(false));
static cl::opt<unsigned> NumRepeatedDivisors(
DEBUG_TYPE "-fp-repeated-divisors", cl::Hidden,
cl::desc("Set the minimum number of repetitions of a divisor to allow "
"transformation to multiplications by the reciprocal"),
cl::init(2));
static cl::opt<int>
FPImmCost(DEBUG_TYPE "-fpimm-cost", cl::Hidden,
cl::desc("Give the maximum number of instructions that we will "
"use for creating a floating-point immediate value"),
cl::init(2));
RISCVTargetLowering::RISCVTargetLowering(const TargetMachine &TM,
const RISCVSubtarget &STI)
: TargetLowering(TM), Subtarget(STI) {
if (Subtarget.isRVE())
report_fatal_error("Codegen not yet implemented for RVE");
RISCVABI::ABI ABI = Subtarget.getTargetABI();
assert(ABI != RISCVABI::ABI_Unknown && "Improperly initialised target ABI");
if ((ABI == RISCVABI::ABI_ILP32F || ABI == RISCVABI::ABI_LP64F) &&
!Subtarget.hasStdExtF()) {
errs() << "Hard-float 'f' ABI can't be used for a target that "
"doesn't support the F instruction set extension (ignoring "
"target-abi)\n";
ABI = Subtarget.is64Bit() ? RISCVABI::ABI_LP64 : RISCVABI::ABI_ILP32;
} else if ((ABI == RISCVABI::ABI_ILP32D || ABI == RISCVABI::ABI_LP64D) &&
!Subtarget.hasStdExtD()) {
errs() << "Hard-float 'd' ABI can't be used for a target that "
"doesn't support the D instruction set extension (ignoring "
"target-abi)\n";
ABI = Subtarget.is64Bit() ? RISCVABI::ABI_LP64 : RISCVABI::ABI_ILP32;
}
switch (ABI) {
default:
report_fatal_error("Don't know how to lower this ABI");
case RISCVABI::ABI_ILP32:
case RISCVABI::ABI_ILP32F:
case RISCVABI::ABI_ILP32D:
case RISCVABI::ABI_LP64:
case RISCVABI::ABI_LP64F:
case RISCVABI::ABI_LP64D:
break;
}
MVT XLenVT = Subtarget.getXLenVT();
// Set up the register classes.
addRegisterClass(XLenVT, &RISCV::GPRRegClass);
if (Subtarget.hasStdExtZfhOrZfhmin())
addRegisterClass(MVT::f16, &RISCV::FPR16RegClass);
if (Subtarget.hasStdExtF())
addRegisterClass(MVT::f32, &RISCV::FPR32RegClass);
if (Subtarget.hasStdExtD())
addRegisterClass(MVT::f64, &RISCV::FPR64RegClass);
static const MVT::SimpleValueType BoolVecVTs[] = {
MVT::nxv1i1, MVT::nxv2i1, MVT::nxv4i1, MVT::nxv8i1,
MVT::nxv16i1, MVT::nxv32i1, MVT::nxv64i1};
static const MVT::SimpleValueType IntVecVTs[] = {
MVT::nxv1i8, MVT::nxv2i8, MVT::nxv4i8, MVT::nxv8i8, MVT::nxv16i8,
MVT::nxv32i8, MVT::nxv64i8, MVT::nxv1i16, MVT::nxv2i16, MVT::nxv4i16,
MVT::nxv8i16, MVT::nxv16i16, MVT::nxv32i16, MVT::nxv1i32, MVT::nxv2i32,
MVT::nxv4i32, MVT::nxv8i32, MVT::nxv16i32, MVT::nxv1i64, MVT::nxv2i64,
MVT::nxv4i64, MVT::nxv8i64};
static const MVT::SimpleValueType F16VecVTs[] = {
MVT::nxv1f16, MVT::nxv2f16, MVT::nxv4f16,
MVT::nxv8f16, MVT::nxv16f16, MVT::nxv32f16};
static const MVT::SimpleValueType F32VecVTs[] = {
MVT::nxv1f32, MVT::nxv2f32, MVT::nxv4f32, MVT::nxv8f32, MVT::nxv16f32};
static const MVT::SimpleValueType F64VecVTs[] = {
MVT::nxv1f64, MVT::nxv2f64, MVT::nxv4f64, MVT::nxv8f64};
if (Subtarget.hasVInstructions()) {
auto addRegClassForRVV = [this](MVT VT) {
// Disable the smallest fractional LMUL types if ELEN is less than
// RVVBitsPerBlock.
unsigned MinElts = RISCV::RVVBitsPerBlock / Subtarget.getELEN();
if (VT.getVectorMinNumElements() < MinElts)
return;
unsigned Size = VT.getSizeInBits().getKnownMinValue();
const TargetRegisterClass *RC;
if (Size <= RISCV::RVVBitsPerBlock)
RC = &RISCV::VRRegClass;
else if (Size == 2 * RISCV::RVVBitsPerBlock)
RC = &RISCV::VRM2RegClass;
else if (Size == 4 * RISCV::RVVBitsPerBlock)
RC = &RISCV::VRM4RegClass;
else if (Size == 8 * RISCV::RVVBitsPerBlock)
RC = &RISCV::VRM8RegClass;
else
llvm_unreachable("Unexpected size");
addRegisterClass(VT, RC);
};
for (MVT VT : BoolVecVTs)
addRegClassForRVV(VT);
for (MVT VT : IntVecVTs) {
if (VT.getVectorElementType() == MVT::i64 &&
!Subtarget.hasVInstructionsI64())
continue;
addRegClassForRVV(VT);
}
if (Subtarget.hasVInstructionsF16())
for (MVT VT : F16VecVTs)
addRegClassForRVV(VT);
if (Subtarget.hasVInstructionsF32())
for (MVT VT : F32VecVTs)
addRegClassForRVV(VT);
if (Subtarget.hasVInstructionsF64())
for (MVT VT : F64VecVTs)
addRegClassForRVV(VT);
if (Subtarget.useRVVForFixedLengthVectors()) {
auto addRegClassForFixedVectors = [this](MVT VT) {
MVT ContainerVT = getContainerForFixedLengthVector(VT);
unsigned RCID = getRegClassIDForVecVT(ContainerVT);
const RISCVRegisterInfo &TRI = *Subtarget.getRegisterInfo();
addRegisterClass(VT, TRI.getRegClass(RCID));
};
for (MVT VT : MVT::integer_fixedlen_vector_valuetypes())
if (useRVVForFixedLengthVectorVT(VT))
addRegClassForFixedVectors(VT);
for (MVT VT : MVT::fp_fixedlen_vector_valuetypes())
if (useRVVForFixedLengthVectorVT(VT))
addRegClassForFixedVectors(VT);
}
}
// Compute derived properties from the register classes.
computeRegisterProperties(STI.getRegisterInfo());
setStackPointerRegisterToSaveRestore(RISCV::X2);
setLoadExtAction({ISD::EXTLOAD, ISD::SEXTLOAD, ISD::ZEXTLOAD}, XLenVT,
MVT::i1, Promote);
// DAGCombiner can call isLoadExtLegal for types that aren't legal.
setLoadExtAction({ISD::EXTLOAD, ISD::SEXTLOAD, ISD::ZEXTLOAD}, MVT::i32,
MVT::i1, Promote);
// TODO: add all necessary setOperationAction calls.
setOperationAction(ISD::DYNAMIC_STACKALLOC, XLenVT, Expand);
setOperationAction(ISD::BR_JT, MVT::Other, Expand);
setOperationAction(ISD::BR_CC, XLenVT, Expand);
setOperationAction(ISD::BRCOND, MVT::Other, Custom);
setOperationAction(ISD::SELECT_CC, XLenVT, Expand);
setCondCodeAction(ISD::SETLE, XLenVT, Expand);
setCondCodeAction(ISD::SETGT, XLenVT, Custom);
setCondCodeAction(ISD::SETGE, XLenVT, Expand);
setCondCodeAction(ISD::SETULE, XLenVT, Expand);
setCondCodeAction(ISD::SETUGT, XLenVT, Custom);
setCondCodeAction(ISD::SETUGE, XLenVT, Expand);
setOperationAction({ISD::STACKSAVE, ISD::STACKRESTORE}, MVT::Other, Expand);
setOperationAction(ISD::VASTART, MVT::Other, Custom);
setOperationAction({ISD::VAARG, ISD::VACOPY, ISD::VAEND}, MVT::Other, Expand);
setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
setOperationAction(ISD::EH_DWARF_CFA, MVT::i32, Custom);
if (!Subtarget.hasStdExtZbb() && !Subtarget.hasVendorXTHeadBb())
setOperationAction(ISD::SIGN_EXTEND_INREG, {MVT::i8, MVT::i16}, Expand);
if (Subtarget.is64Bit()) {
setOperationAction(ISD::EH_DWARF_CFA, MVT::i64, Custom);
setOperationAction(ISD::LOAD, MVT::i32, Custom);
setOperationAction({ISD::ADD, ISD::SUB, ISD::SHL, ISD::SRA, ISD::SRL},
MVT::i32, Custom);
setOperationAction({ISD::UADDO, ISD::USUBO, ISD::UADDSAT, ISD::USUBSAT},
MVT::i32, Custom);
} else {
setLibcallName(
{RTLIB::SHL_I128, RTLIB::SRL_I128, RTLIB::SRA_I128, RTLIB::MUL_I128},
nullptr);
setLibcallName(RTLIB::MULO_I64, nullptr);
}
if (!Subtarget.hasStdExtM() && !Subtarget.hasStdExtZmmul()) {
setOperationAction({ISD::MUL, ISD::MULHS, ISD::MULHU}, XLenVT, Expand);
} else {
if (Subtarget.is64Bit()) {
setOperationAction(ISD::MUL, {MVT::i32, MVT::i128}, Custom);
} else {
setOperationAction(ISD::MUL, MVT::i64, Custom);
}
}
if (!Subtarget.hasStdExtM()) {
setOperationAction({ISD::SDIV, ISD::UDIV, ISD::SREM, ISD::UREM},
XLenVT, Expand);
} else {
if (Subtarget.is64Bit()) {
setOperationAction({ISD::SDIV, ISD::UDIV, ISD::UREM},
{MVT::i8, MVT::i16, MVT::i32}, Custom);
}
}
setOperationAction(
{ISD::SDIVREM, ISD::UDIVREM, ISD::SMUL_LOHI, ISD::UMUL_LOHI}, XLenVT,
Expand);
setOperationAction({ISD::SHL_PARTS, ISD::SRL_PARTS, ISD::SRA_PARTS}, XLenVT,
Custom);
if (Subtarget.hasStdExtZbb() || Subtarget.hasStdExtZbkb() ||
Subtarget.hasVendorXTHeadBb()) {
if (Subtarget.is64Bit())
setOperationAction({ISD::ROTL, ISD::ROTR}, MVT::i32, Custom);
} else {
setOperationAction({ISD::ROTL, ISD::ROTR}, XLenVT, Expand);
}
// With Zbb we have an XLen rev8 instruction, but not GREVI. So we'll
// pattern match it directly in isel.
setOperationAction(ISD::BSWAP, XLenVT,
(Subtarget.hasStdExtZbb() || Subtarget.hasStdExtZbkb() ||
Subtarget.hasVendorXTHeadBb())
? Legal
: Expand);
// Zbkb can use rev8+brev8 to implement bitreverse.
setOperationAction(ISD::BITREVERSE, XLenVT,
Subtarget.hasStdExtZbkb() ? Custom : Expand);
if (Subtarget.hasStdExtZbb()) {
setOperationAction({ISD::SMIN, ISD::SMAX, ISD::UMIN, ISD::UMAX}, XLenVT,
Legal);
if (Subtarget.is64Bit())
setOperationAction(
{ISD::CTTZ, ISD::CTTZ_ZERO_UNDEF, ISD::CTLZ, ISD::CTLZ_ZERO_UNDEF},
MVT::i32, Custom);
} else {
setOperationAction({ISD::CTTZ, ISD::CTLZ, ISD::CTPOP}, XLenVT, Expand);
}
if (Subtarget.hasVendorXTHeadBb()) {
setOperationAction(ISD::CTLZ, XLenVT, Legal);
// We need the custom lowering to make sure that the resulting sequence
// for the 32bit case is efficient on 64bit targets.
if (Subtarget.is64Bit())
setOperationAction({ISD::CTLZ, ISD::CTLZ_ZERO_UNDEF}, MVT::i32, Custom);
}
if (Subtarget.is64Bit())
setOperationAction(ISD::ABS, MVT::i32, Custom);
if (!Subtarget.hasStdExtZicond() && !Subtarget.hasVendorXVentanaCondOps() &&
!Subtarget.hasVendorXTHeadCondMov())
setOperationAction(ISD::SELECT, XLenVT, Custom);
static const unsigned FPLegalNodeTypes[] = {
ISD::FMINNUM, ISD::FMAXNUM, ISD::LRINT,
ISD::LLRINT, ISD::LROUND, ISD::LLROUND,
ISD::STRICT_LRINT, ISD::STRICT_LLRINT, ISD::STRICT_LROUND,
ISD::STRICT_LLROUND, ISD::STRICT_FMA, ISD::STRICT_FADD,
ISD::STRICT_FSUB, ISD::STRICT_FMUL, ISD::STRICT_FDIV,
ISD::STRICT_FSQRT, ISD::STRICT_FSETCC, ISD::STRICT_FSETCCS};
static const ISD::CondCode FPCCToExpand[] = {
ISD::SETOGT, ISD::SETOGE, ISD::SETONE, ISD::SETUEQ, ISD::SETUGT,
ISD::SETUGE, ISD::SETULT, ISD::SETULE, ISD::SETUNE, ISD::SETGT,
ISD::SETGE, ISD::SETNE, ISD::SETO, ISD::SETUO};
static const unsigned FPOpToExpand[] = {
ISD::FSIN, ISD::FCOS, ISD::FSINCOS, ISD::FPOW,
ISD::FREM, ISD::FP16_TO_FP, ISD::FP_TO_FP16};
static const unsigned FPRndMode[] = {
ISD::FCEIL, ISD::FFLOOR, ISD::FTRUNC, ISD::FRINT, ISD::FROUND,
ISD::FROUNDEVEN};
if (Subtarget.hasStdExtZfhOrZfhmin())
setOperationAction(ISD::BITCAST, MVT::i16, Custom);
if (Subtarget.hasStdExtZfhOrZfhmin()) {
if (Subtarget.hasStdExtZfh()) {
setOperationAction(FPLegalNodeTypes, MVT::f16, Legal);
setOperationAction(FPRndMode, MVT::f16,
Subtarget.hasStdExtZfa() ? Legal : Custom);
setOperationAction(ISD::SELECT, MVT::f16, Custom);
} else {
static const unsigned ZfhminPromoteOps[] = {
ISD::FMINNUM, ISD::FMAXNUM, ISD::FADD,
ISD::FSUB, ISD::FMUL, ISD::FMA,
ISD::FDIV, ISD::FSQRT, ISD::FABS,
ISD::FNEG, ISD::STRICT_FMA, ISD::STRICT_FADD,
ISD::STRICT_FSUB, ISD::STRICT_FMUL, ISD::STRICT_FDIV,
ISD::STRICT_FSQRT, ISD::STRICT_FSETCC, ISD::STRICT_FSETCCS,
ISD::SETCC, ISD::FCEIL, ISD::FFLOOR,
ISD::FTRUNC, ISD::FRINT, ISD::FROUND,
ISD::FROUNDEVEN, ISD::SELECT};
setOperationAction(ZfhminPromoteOps, MVT::f16, Promote);
setOperationAction({ISD::STRICT_LRINT, ISD::STRICT_LLRINT,
ISD::STRICT_LROUND, ISD::STRICT_LLROUND},
MVT::f16, Legal);
// FIXME: Need to promote f16 FCOPYSIGN to f32, but the
// DAGCombiner::visitFP_ROUND probably needs improvements first.
setOperationAction(ISD::FCOPYSIGN, MVT::f16, Expand);
}
setOperationAction(ISD::STRICT_FP_ROUND, MVT::f16, Legal);
setOperationAction(ISD::STRICT_FP_EXTEND, MVT::f32, Legal);
setCondCodeAction(FPCCToExpand, MVT::f16, Expand);
setOperationAction(ISD::SELECT_CC, MVT::f16, Expand);
setOperationAction(ISD::BR_CC, MVT::f16, Expand);
setOperationAction(ISD::FNEARBYINT, MVT::f16,
Subtarget.hasStdExtZfa() ? Legal : Promote);
setOperationAction({ISD::FREM, ISD::FPOW, ISD::FPOWI,
ISD::FCOS, ISD::FSIN, ISD::FSINCOS, ISD::FEXP,
ISD::FEXP2, ISD::FLOG, ISD::FLOG2, ISD::FLOG10},
MVT::f16, Promote);
// FIXME: Need to promote f16 STRICT_* to f32 libcalls, but we don't have
// complete support for all operations in LegalizeDAG.
setOperationAction({ISD::STRICT_FCEIL, ISD::STRICT_FFLOOR,
ISD::STRICT_FNEARBYINT, ISD::STRICT_FRINT,
ISD::STRICT_FROUND, ISD::STRICT_FROUNDEVEN,
ISD::STRICT_FTRUNC},
MVT::f16, Promote);
// We need to custom promote this.
if (Subtarget.is64Bit())
setOperationAction(ISD::FPOWI, MVT::i32, Custom);
}
if (Subtarget.hasStdExtF()) {
setOperationAction(FPLegalNodeTypes, MVT::f32, Legal);
setOperationAction(FPRndMode, MVT::f32,
Subtarget.hasStdExtZfa() ? Legal : Custom);
setCondCodeAction(FPCCToExpand, MVT::f32, Expand);
setOperationAction(ISD::SELECT_CC, MVT::f32, Expand);
setOperationAction(ISD::SELECT, MVT::f32, Custom);
setOperationAction(ISD::BR_CC, MVT::f32, Expand);
setOperationAction(FPOpToExpand, MVT::f32, Expand);
setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
setTruncStoreAction(MVT::f32, MVT::f16, Expand);
if (Subtarget.hasStdExtZfa())
setOperationAction(ISD::FNEARBYINT, MVT::f32, Legal);
}
if (Subtarget.hasStdExtF() && Subtarget.is64Bit())
setOperationAction(ISD::BITCAST, MVT::i32, Custom);
if (Subtarget.hasStdExtD()) {
setOperationAction(FPLegalNodeTypes, MVT::f64, Legal);
if (Subtarget.hasStdExtZfa()) {
setOperationAction(FPRndMode, MVT::f64, Legal);
setOperationAction(ISD::FNEARBYINT, MVT::f64, Legal);
setOperationAction(ISD::BITCAST, MVT::i64, Custom);
setOperationAction(ISD::BITCAST, MVT::f64, Custom);
}
if (Subtarget.is64Bit())
setOperationAction(FPRndMode, MVT::f64,
Subtarget.hasStdExtZfa() ? Legal : Custom);
setOperationAction(ISD::STRICT_FP_ROUND, MVT::f32, Legal);
setOperationAction(ISD::STRICT_FP_EXTEND, MVT::f64, Legal);
setCondCodeAction(FPCCToExpand, MVT::f64, Expand);
setOperationAction(ISD::SELECT_CC, MVT::f64, Expand);
setOperationAction(ISD::SELECT, MVT::f64, Custom);
setOperationAction(ISD::BR_CC, MVT::f64, Expand);
setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f32, Expand);
setTruncStoreAction(MVT::f64, MVT::f32, Expand);
setOperationAction(FPOpToExpand, MVT::f64, Expand);
setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f16, Expand);
setTruncStoreAction(MVT::f64, MVT::f16, Expand);
}
if (Subtarget.is64Bit()) {
setOperationAction({ISD::FP_TO_UINT, ISD::FP_TO_SINT,
ISD::STRICT_FP_TO_UINT, ISD::STRICT_FP_TO_SINT},
MVT::i32, Custom);
setOperationAction(ISD::LROUND, MVT::i32, Custom);
}
if (Subtarget.hasStdExtF()) {
setOperationAction({ISD::FP_TO_UINT_SAT, ISD::FP_TO_SINT_SAT}, XLenVT,
Custom);
setOperationAction({ISD::STRICT_FP_TO_UINT, ISD::STRICT_FP_TO_SINT,
ISD::STRICT_UINT_TO_FP, ISD::STRICT_SINT_TO_FP},
XLenVT, Legal);
setOperationAction(ISD::GET_ROUNDING, XLenVT, Custom);
setOperationAction(ISD::SET_ROUNDING, MVT::Other, Custom);
}
setOperationAction({ISD::GlobalAddress, ISD::BlockAddress, ISD::ConstantPool,
ISD::JumpTable},
XLenVT, Custom);
setOperationAction(ISD::GlobalTLSAddress, XLenVT, Custom);
if (Subtarget.is64Bit())
setOperationAction(ISD::Constant, MVT::i64, Custom);
// TODO: On M-mode only targets, the cycle[h] CSR may not be present.
// Unfortunately this can't be determined just from the ISA naming string.
setOperationAction(ISD::READCYCLECOUNTER, MVT::i64,
Subtarget.is64Bit() ? Legal : Custom);
setOperationAction({ISD::TRAP, ISD::DEBUGTRAP}, MVT::Other, Legal);
setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
if (Subtarget.is64Bit())
setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::i32, Custom);
if (Subtarget.hasStdExtA()) {
setMaxAtomicSizeInBitsSupported(Subtarget.getXLen());
setMinCmpXchgSizeInBits(32);
} else if (Subtarget.hasForcedAtomics()) {
setMaxAtomicSizeInBitsSupported(Subtarget.getXLen());
} else {
setMaxAtomicSizeInBitsSupported(0);
}
setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Custom);
setBooleanContents(ZeroOrOneBooleanContent);
if (Subtarget.hasVInstructions()) {
setBooleanVectorContents(ZeroOrOneBooleanContent);
setOperationAction(ISD::VSCALE, XLenVT, Custom);
// RVV intrinsics may have illegal operands.
// We also need to custom legalize vmv.x.s.
setOperationAction({ISD::INTRINSIC_WO_CHAIN, ISD::INTRINSIC_W_CHAIN},
{MVT::i8, MVT::i16}, Custom);
if (Subtarget.is64Bit())
setOperationAction(ISD::INTRINSIC_W_CHAIN, MVT::i32, Custom);
else
setOperationAction({ISD::INTRINSIC_WO_CHAIN, ISD::INTRINSIC_W_CHAIN},
MVT::i64, Custom);
setOperationAction({ISD::INTRINSIC_W_CHAIN, ISD::INTRINSIC_VOID},
MVT::Other, Custom);
static const unsigned IntegerVPOps[] = {
ISD::VP_ADD, ISD::VP_SUB, ISD::VP_MUL,
ISD::VP_SDIV, ISD::VP_UDIV, ISD::VP_SREM,
ISD::VP_UREM, ISD::VP_AND, ISD::VP_OR,
ISD::VP_XOR, ISD::VP_ASHR, ISD::VP_LSHR,
ISD::VP_SHL, ISD::VP_REDUCE_ADD, ISD::VP_REDUCE_AND,
ISD::VP_REDUCE_OR, ISD::VP_REDUCE_XOR, ISD::VP_REDUCE_SMAX,
ISD::VP_REDUCE_SMIN, ISD::VP_REDUCE_UMAX, ISD::VP_REDUCE_UMIN,
ISD::VP_MERGE, ISD::VP_SELECT, ISD::VP_FP_TO_SINT,
ISD::VP_FP_TO_UINT, ISD::VP_SETCC, ISD::VP_SIGN_EXTEND,
ISD::VP_ZERO_EXTEND, ISD::VP_TRUNCATE, ISD::VP_SMIN,
ISD::VP_SMAX, ISD::VP_UMIN, ISD::VP_UMAX,
ISD::VP_ABS};
static const unsigned FloatingPointVPOps[] = {
ISD::VP_FADD, ISD::VP_FSUB, ISD::VP_FMUL,
ISD::VP_FDIV, ISD::VP_FNEG, ISD::VP_FABS,
ISD::VP_FMA, ISD::VP_REDUCE_FADD, ISD::VP_REDUCE_SEQ_FADD,
ISD::VP_REDUCE_FMIN, ISD::VP_REDUCE_FMAX, ISD::VP_MERGE,
ISD::VP_SELECT, ISD::VP_SINT_TO_FP, ISD::VP_UINT_TO_FP,
ISD::VP_SETCC, ISD::VP_FP_ROUND, ISD::VP_FP_EXTEND,
ISD::VP_SQRT, ISD::VP_FMINNUM, ISD::VP_FMAXNUM,
ISD::VP_FCEIL, ISD::VP_FFLOOR, ISD::VP_FROUND,
ISD::VP_FROUNDEVEN, ISD::VP_FCOPYSIGN, ISD::VP_FROUNDTOZERO,
ISD::VP_FRINT, ISD::VP_FNEARBYINT};
static const unsigned IntegerVecReduceOps[] = {
ISD::VECREDUCE_ADD, ISD::VECREDUCE_AND, ISD::VECREDUCE_OR,
ISD::VECREDUCE_XOR, ISD::VECREDUCE_SMAX, ISD::VECREDUCE_SMIN,
ISD::VECREDUCE_UMAX, ISD::VECREDUCE_UMIN};
static const unsigned FloatingPointVecReduceOps[] = {
ISD::VECREDUCE_FADD, ISD::VECREDUCE_SEQ_FADD, ISD::VECREDUCE_FMIN,
ISD::VECREDUCE_FMAX};
if (!Subtarget.is64Bit()) {
// We must custom-lower certain vXi64 operations on RV32 due to the vector
// element type being illegal.
setOperationAction({ISD::INSERT_VECTOR_ELT, ISD::EXTRACT_VECTOR_ELT},
MVT::i64, Custom);
setOperationAction(IntegerVecReduceOps, MVT::i64, Custom);
setOperationAction({ISD::VP_REDUCE_ADD, ISD::VP_REDUCE_AND,
ISD::VP_REDUCE_OR, ISD::VP_REDUCE_XOR,
ISD::VP_REDUCE_SMAX, ISD::VP_REDUCE_SMIN,
ISD::VP_REDUCE_UMAX, ISD::VP_REDUCE_UMIN},
MVT::i64, Custom);
}
for (MVT VT : BoolVecVTs) {
if (!isTypeLegal(VT))
continue;
setOperationAction(ISD::SPLAT_VECTOR, VT, Custom);
// Mask VTs are custom-expanded into a series of standard nodes
setOperationAction({ISD::TRUNCATE, ISD::CONCAT_VECTORS,
ISD::INSERT_SUBVECTOR, ISD::EXTRACT_SUBVECTOR,
ISD::SCALAR_TO_VECTOR},
VT, Custom);
setOperationAction({ISD::INSERT_VECTOR_ELT, ISD::EXTRACT_VECTOR_ELT}, VT,
Custom);
setOperationAction(ISD::SELECT, VT, Custom);
setOperationAction(
{ISD::SELECT_CC, ISD::VSELECT, ISD::VP_MERGE, ISD::VP_SELECT}, VT,
Expand);
setOperationAction({ISD::VP_AND, ISD::VP_OR, ISD::VP_XOR}, VT, Custom);
setOperationAction(
{ISD::VECREDUCE_AND, ISD::VECREDUCE_OR, ISD::VECREDUCE_XOR}, VT,
Custom);
setOperationAction(
{ISD::VP_REDUCE_AND, ISD::VP_REDUCE_OR, ISD::VP_REDUCE_XOR}, VT,
Custom);
// RVV has native int->float & float->int conversions where the
// element type sizes are within one power-of-two of each other. Any
// wider distances between type sizes have to be lowered as sequences
// which progressively narrow the gap in stages.
setOperationAction({ISD::SINT_TO_FP, ISD::UINT_TO_FP, ISD::FP_TO_SINT,
ISD::FP_TO_UINT, ISD::STRICT_SINT_TO_FP,
ISD::STRICT_UINT_TO_FP, ISD::STRICT_FP_TO_SINT,
ISD::STRICT_FP_TO_UINT},
VT, Custom);
setOperationAction({ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT}, VT,
Custom);
// Expand all extending loads to types larger than this, and truncating
// stores from types larger than this.
for (MVT OtherVT : MVT::integer_scalable_vector_valuetypes()) {
setTruncStoreAction(OtherVT, VT, Expand);
setLoadExtAction({ISD::EXTLOAD, ISD::SEXTLOAD, ISD::ZEXTLOAD}, OtherVT,
VT, Expand);
}
setOperationAction({ISD::VP_FP_TO_SINT, ISD::VP_FP_TO_UINT,
ISD::VP_TRUNCATE, ISD::VP_SETCC},
VT, Custom);
setOperationAction(ISD::VECTOR_DEINTERLEAVE, VT, Custom);
setOperationAction(ISD::VECTOR_INTERLEAVE, VT, Custom);
setOperationAction(ISD::VECTOR_REVERSE, VT, Custom);
setOperationPromotedToType(
ISD::VECTOR_SPLICE, VT,
MVT::getVectorVT(MVT::i8, VT.getVectorElementCount()));
}
for (MVT VT : IntVecVTs) {
if (!isTypeLegal(VT))
continue;
setOperationAction(ISD::SPLAT_VECTOR, VT, Legal);
setOperationAction(ISD::SPLAT_VECTOR_PARTS, VT, Custom);
// Vectors implement MULHS/MULHU.
setOperationAction({ISD::SMUL_LOHI, ISD::UMUL_LOHI}, VT, Expand);
// nxvXi64 MULHS/MULHU requires the V extension instead of Zve64*.
if (VT.getVectorElementType() == MVT::i64 && !Subtarget.hasStdExtV())
setOperationAction({ISD::MULHU, ISD::MULHS}, VT, Expand);
setOperationAction({ISD::SMIN, ISD::SMAX, ISD::UMIN, ISD::UMAX}, VT,
Legal);
setOperationAction({ISD::ROTL, ISD::ROTR}, VT, Expand);
setOperationAction({ISD::CTTZ, ISD::CTLZ, ISD::CTPOP}, VT, Expand);
setOperationAction(ISD::BSWAP, VT, Expand);
setOperationAction({ISD::VP_BSWAP, ISD::VP_BITREVERSE}, VT, Expand);
setOperationAction({ISD::VP_FSHL, ISD::VP_FSHR}, VT, Expand);
setOperationAction({ISD::VP_CTLZ, ISD::VP_CTLZ_ZERO_UNDEF, ISD::VP_CTTZ,
ISD::VP_CTTZ_ZERO_UNDEF, ISD::VP_CTPOP},
VT, Expand);
// Custom-lower extensions and truncations from/to mask types.
setOperationAction({ISD::ANY_EXTEND, ISD::SIGN_EXTEND, ISD::ZERO_EXTEND},
VT, Custom);
// RVV has native int->float & float->int conversions where the
// element type sizes are within one power-of-two of each other. Any
// wider distances between type sizes have to be lowered as sequences
// which progressively narrow the gap in stages.
setOperationAction({ISD::SINT_TO_FP, ISD::UINT_TO_FP, ISD::FP_TO_SINT,
ISD::FP_TO_UINT, ISD::STRICT_SINT_TO_FP,
ISD::STRICT_UINT_TO_FP, ISD::STRICT_FP_TO_SINT,
ISD::STRICT_FP_TO_UINT},
VT, Custom);
setOperationAction({ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT}, VT,
Custom);
setOperationAction(
{ISD::SADDSAT, ISD::UADDSAT, ISD::SSUBSAT, ISD::USUBSAT}, VT, Legal);
// Integer VTs are lowered as a series of "RISCVISD::TRUNCATE_VECTOR_VL"
// nodes which truncate by one power of two at a time.
setOperationAction(ISD::TRUNCATE, VT, Custom);
// Custom-lower insert/extract operations to simplify patterns.
setOperationAction({ISD::INSERT_VECTOR_ELT, ISD::EXTRACT_VECTOR_ELT}, VT,
Custom);
// Custom-lower reduction operations to set up the corresponding custom
// nodes' operands.
setOperationAction(IntegerVecReduceOps, VT, Custom);
setOperationAction(IntegerVPOps, VT, Custom);
setOperationAction({ISD::LOAD, ISD::STORE}, VT, Custom);
setOperationAction({ISD::MLOAD, ISD::MSTORE, ISD::MGATHER, ISD::MSCATTER},
VT, Custom);
setOperationAction(
{ISD::VP_LOAD, ISD::VP_STORE, ISD::EXPERIMENTAL_VP_STRIDED_LOAD,
ISD::EXPERIMENTAL_VP_STRIDED_STORE, ISD::VP_GATHER, ISD::VP_SCATTER},
VT, Custom);
setOperationAction({ISD::CONCAT_VECTORS, ISD::INSERT_SUBVECTOR,
ISD::EXTRACT_SUBVECTOR, ISD::SCALAR_TO_VECTOR},
VT, Custom);
setOperationAction(ISD::SELECT, VT, Custom);
setOperationAction(ISD::SELECT_CC, VT, Expand);
setOperationAction({ISD::STEP_VECTOR, ISD::VECTOR_REVERSE}, VT, Custom);
for (MVT OtherVT : MVT::integer_scalable_vector_valuetypes()) {
setTruncStoreAction(VT, OtherVT, Expand);
setLoadExtAction({ISD::EXTLOAD, ISD::SEXTLOAD, ISD::ZEXTLOAD}, OtherVT,
VT, Expand);
}
setOperationAction(ISD::VECTOR_DEINTERLEAVE, VT, Custom);
setOperationAction(ISD::VECTOR_INTERLEAVE, VT, Custom);
// Splice
setOperationAction(ISD::VECTOR_SPLICE, VT, Custom);
// Lower CTLZ_ZERO_UNDEF and CTTZ_ZERO_UNDEF if element of VT in the range
// of f32.
EVT FloatVT = MVT::getVectorVT(MVT::f32, VT.getVectorElementCount());
if (isTypeLegal(FloatVT)) {
setOperationAction(
{ISD::CTLZ, ISD::CTLZ_ZERO_UNDEF, ISD::CTTZ_ZERO_UNDEF}, VT,
Custom);
}
}
// Expand various CCs to best match the RVV ISA, which natively supports UNE
// but no other unordered comparisons, and supports all ordered comparisons
// except ONE. Additionally, we expand GT,OGT,GE,OGE for optimization
// purposes; they are expanded to their swapped-operand CCs (LT,OLT,LE,OLE),
// and we pattern-match those back to the "original", swapping operands once
// more. This way we catch both operations and both "vf" and "fv" forms with
// fewer patterns.
static const ISD::CondCode VFPCCToExpand[] = {
ISD::SETO, ISD::SETONE, ISD::SETUEQ, ISD::SETUGT,
ISD::SETUGE, ISD::SETULT, ISD::SETULE, ISD::SETUO,
ISD::SETGT, ISD::SETOGT, ISD::SETGE, ISD::SETOGE,
};
// Sets common operation actions on RVV floating-point vector types.
const auto SetCommonVFPActions = [&](MVT VT) {
setOperationAction(ISD::SPLAT_VECTOR, VT, Legal);
// RVV has native FP_ROUND & FP_EXTEND conversions where the element type
// sizes are within one power-of-two of each other. Therefore conversions
// between vXf16 and vXf64 must be lowered as sequences which convert via
// vXf32.
setOperationAction({ISD::FP_ROUND, ISD::FP_EXTEND}, VT, Custom);
// Custom-lower insert/extract operations to simplify patterns.
setOperationAction({ISD::INSERT_VECTOR_ELT, ISD::EXTRACT_VECTOR_ELT}, VT,
Custom);
// Expand various condition codes (explained above).
setCondCodeAction(VFPCCToExpand, VT, Expand);
setOperationAction({ISD::FMINNUM, ISD::FMAXNUM}, VT, Legal);
setOperationAction(
{ISD::FTRUNC, ISD::FCEIL, ISD::FFLOOR, ISD::FROUND, ISD::FROUNDEVEN},
VT, Custom);
setOperationAction(FloatingPointVecReduceOps, VT, Custom);
// Expand FP operations that need libcalls.
setOperationAction(ISD::FREM, VT, Expand);
setOperationAction(ISD::FPOW, VT, Expand);
setOperationAction(ISD::FCOS, VT, Expand);
setOperationAction(ISD::FSIN, VT, Expand);
setOperationAction(ISD::FSINCOS, VT, Expand);
setOperationAction(ISD::FEXP, VT, Expand);
setOperationAction(ISD::FEXP2, VT, Expand);
setOperationAction(ISD::FLOG, VT, Expand);
setOperationAction(ISD::FLOG2, VT, Expand);
setOperationAction(ISD::FLOG10, VT, Expand);
setOperationAction(ISD::FRINT, VT, Expand);
setOperationAction(ISD::FNEARBYINT, VT, Expand);
setOperationAction(ISD::FCOPYSIGN, VT, Legal);
setOperationAction({ISD::LOAD, ISD::STORE}, VT, Custom);
setOperationAction({ISD::MLOAD, ISD::MSTORE, ISD::MGATHER, ISD::MSCATTER},
VT, Custom);
setOperationAction(
{ISD::VP_LOAD, ISD::VP_STORE, ISD::EXPERIMENTAL_VP_STRIDED_LOAD,
ISD::EXPERIMENTAL_VP_STRIDED_STORE, ISD::VP_GATHER, ISD::VP_SCATTER},
VT, Custom);
setOperationAction(ISD::SELECT, VT, Custom);
setOperationAction(ISD::SELECT_CC, VT, Expand);
setOperationAction({ISD::CONCAT_VECTORS, ISD::INSERT_SUBVECTOR,
ISD::EXTRACT_SUBVECTOR, ISD::SCALAR_TO_VECTOR},
VT, Custom);
setOperationAction(ISD::VECTOR_DEINTERLEAVE, VT, Custom);
setOperationAction(ISD::VECTOR_INTERLEAVE, VT, Custom);
setOperationAction({ISD::VECTOR_REVERSE, ISD::VECTOR_SPLICE}, VT, Custom);
setOperationAction(FloatingPointVPOps, VT, Custom);
setOperationAction({ISD::STRICT_FP_EXTEND, ISD::STRICT_FP_ROUND}, VT,
Custom);
setOperationAction({ISD::STRICT_FADD, ISD::STRICT_FSUB, ISD::STRICT_FMUL,
ISD::STRICT_FDIV, ISD::STRICT_FSQRT, ISD::STRICT_FMA},
VT, Legal);
setOperationAction({ISD::STRICT_FSETCC, ISD::STRICT_FSETCCS}, VT, Custom);
};
// Sets common extload/truncstore actions on RVV floating-point vector
// types.
const auto SetCommonVFPExtLoadTruncStoreActions =
[&](MVT VT, ArrayRef<MVT::SimpleValueType> SmallerVTs) {
for (auto SmallVT : SmallerVTs) {
setTruncStoreAction(VT, SmallVT, Expand);
setLoadExtAction(ISD::EXTLOAD, VT, SmallVT, Expand);
}
};
if (Subtarget.hasVInstructionsF16()) {
for (MVT VT : F16VecVTs) {
if (!isTypeLegal(VT))
continue;
SetCommonVFPActions(VT);
}
}
if (Subtarget.hasVInstructionsF32()) {
for (MVT VT : F32VecVTs) {
if (!isTypeLegal(VT))
continue;
SetCommonVFPActions(VT);
SetCommonVFPExtLoadTruncStoreActions(VT, F16VecVTs);
}
}
if (Subtarget.hasVInstructionsF64()) {
for (MVT VT : F64VecVTs) {
if (!isTypeLegal(VT))
continue;
SetCommonVFPActions(VT);
SetCommonVFPExtLoadTruncStoreActions(VT, F16VecVTs);
SetCommonVFPExtLoadTruncStoreActions(VT, F32VecVTs);
}
}
if (Subtarget.useRVVForFixedLengthVectors()) {
for (MVT VT : MVT::integer_fixedlen_vector_valuetypes()) {
if (!useRVVForFixedLengthVectorVT(VT))
continue;
// By default everything must be expanded.
for (unsigned Op = 0; Op < ISD::BUILTIN_OP_END; ++Op)
setOperationAction(Op, VT, Expand);
for (MVT OtherVT : MVT::integer_fixedlen_vector_valuetypes()) {
setTruncStoreAction(VT, OtherVT, Expand);
setLoadExtAction({ISD::EXTLOAD, ISD::SEXTLOAD, ISD::ZEXTLOAD},
OtherVT, VT, Expand);
}
// We use EXTRACT_SUBVECTOR as a "cast" from scalable to fixed.
setOperationAction({ISD::INSERT_SUBVECTOR, ISD::EXTRACT_SUBVECTOR}, VT,
Custom);
setOperationAction({ISD::BUILD_VECTOR, ISD::CONCAT_VECTORS}, VT,
Custom);
setOperationAction({ISD::INSERT_VECTOR_ELT, ISD::EXTRACT_VECTOR_ELT},
VT, Custom);
setOperationAction(ISD::SCALAR_TO_VECTOR, VT, Custom);
setOperationAction({ISD::LOAD, ISD::STORE}, VT, Custom);
setOperationAction(ISD::SETCC, VT, Custom);
setOperationAction({ISD::STRICT_FSETCC, ISD::STRICT_FSETCCS}, VT,
Legal);
setOperationAction(ISD::SELECT, VT, Custom);
setOperationAction(ISD::TRUNCATE, VT, Custom);
setOperationAction(ISD::BITCAST, VT, Custom);
setOperationAction(
{ISD::VECREDUCE_AND, ISD::VECREDUCE_OR, ISD::VECREDUCE_XOR}, VT,
Custom);
setOperationAction(
{ISD::VP_REDUCE_AND, ISD::VP_REDUCE_OR, ISD::VP_REDUCE_XOR}, VT,
Custom);
setOperationAction(
{
ISD::SINT_TO_FP,
ISD::UINT_TO_FP,
ISD::FP_TO_SINT,
ISD::FP_TO_UINT,
ISD::STRICT_SINT_TO_FP,
ISD::STRICT_UINT_TO_FP,
ISD::STRICT_FP_TO_SINT,
ISD::STRICT_FP_TO_UINT,
},
VT, Custom);
setOperationAction({ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT}, VT,
Custom);
// Operations below are different for between masks and other vectors.
if (VT.getVectorElementType() == MVT::i1) {
setOperationAction({ISD::VP_AND, ISD::VP_OR, ISD::VP_XOR, ISD::AND,
ISD::OR, ISD::XOR},
VT, Custom);
setOperationAction({ISD::VP_FP_TO_SINT, ISD::VP_FP_TO_UINT,
ISD::VP_SETCC, ISD::VP_TRUNCATE},
VT, Custom);
continue;
}
// Make SPLAT_VECTOR Legal so DAGCombine will convert splat vectors to
// it before type legalization for i64 vectors on RV32. It will then be
// type legalized to SPLAT_VECTOR_PARTS which we need to Custom handle.
// FIXME: Use SPLAT_VECTOR for all types? DAGCombine probably needs
// improvements first.
if (!Subtarget.is64Bit() && VT.getVectorElementType() == MVT::i64) {
setOperationAction(ISD::SPLAT_VECTOR, VT, Legal);
setOperationAction(ISD::SPLAT_VECTOR_PARTS, VT, Custom);
}
setOperationAction(ISD::VECTOR_SHUFFLE, VT, Custom);
setOperationAction(
{ISD::MLOAD, ISD::MSTORE, ISD::MGATHER, ISD::MSCATTER}, VT, Custom);
setOperationAction({ISD::VP_LOAD, ISD::VP_STORE,
ISD::EXPERIMENTAL_VP_STRIDED_LOAD,
ISD::EXPERIMENTAL_VP_STRIDED_STORE, ISD::VP_GATHER,
ISD::VP_SCATTER},
VT, Custom);
setOperationAction({ISD::ADD, ISD::MUL, ISD::SUB, ISD::AND, ISD::OR,
ISD::XOR, ISD::SDIV, ISD::SREM, ISD::UDIV,
ISD::UREM, ISD::SHL, ISD::SRA, ISD::SRL},
VT, Custom);
setOperationAction(
{ISD::SMIN, ISD::SMAX, ISD::UMIN, ISD::UMAX, ISD::ABS}, VT, Custom);
// vXi64 MULHS/MULHU requires the V extension instead of Zve64*.
if (VT.getVectorElementType() != MVT::i64 || Subtarget.hasStdExtV())
setOperationAction({ISD::MULHS, ISD::MULHU}, VT, Custom);
setOperationAction(
{ISD::SADDSAT, ISD::UADDSAT, ISD::SSUBSAT, ISD::USUBSAT}, VT,
Custom);
setOperationAction(ISD::VSELECT, VT, Custom);
setOperationAction(ISD::SELECT_CC, VT, Expand);
setOperationAction(
{ISD::ANY_EXTEND, ISD::SIGN_EXTEND, ISD::ZERO_EXTEND}, VT, Custom);
// Custom-lower reduction operations to set up the corresponding custom
// nodes' operands.
setOperationAction({ISD::VECREDUCE_ADD, ISD::VECREDUCE_SMAX,
ISD::VECREDUCE_SMIN, ISD::VECREDUCE_UMAX,
ISD::VECREDUCE_UMIN},
VT, Custom);
setOperationAction(IntegerVPOps, VT, Custom);
// Lower CTLZ_ZERO_UNDEF and CTTZ_ZERO_UNDEF if element of VT in the
// range of f32.
EVT FloatVT = MVT::getVectorVT(MVT::f32, VT.getVectorElementCount());
if (isTypeLegal(FloatVT))
setOperationAction(
{ISD::CTLZ, ISD::CTLZ_ZERO_UNDEF, ISD::CTTZ_ZERO_UNDEF}, VT,
Custom);
}
for (MVT VT : MVT::fp_fixedlen_vector_valuetypes()) {
if (!useRVVForFixedLengthVectorVT(VT))
continue;
// By default everything must be expanded.
for (unsigned Op = 0; Op < ISD::BUILTIN_OP_END; ++Op)
setOperationAction(Op, VT, Expand);
for (MVT OtherVT : MVT::fp_fixedlen_vector_valuetypes()) {
setLoadExtAction(ISD::EXTLOAD, OtherVT, VT, Expand);
setTruncStoreAction(VT, OtherVT, Expand);
}
// We use EXTRACT_SUBVECTOR as a "cast" from scalable to fixed.
setOperationAction({ISD::INSERT_SUBVECTOR, ISD::EXTRACT_SUBVECTOR}, VT,
Custom);
setOperationAction({ISD::BUILD_VECTOR, ISD::CONCAT_VECTORS,
ISD::VECTOR_SHUFFLE, ISD::INSERT_VECTOR_ELT,
ISD::EXTRACT_VECTOR_ELT},
VT, Custom);
setOperationAction({ISD::LOAD, ISD::STORE, ISD::MLOAD, ISD::MSTORE,
ISD::MGATHER, ISD::MSCATTER},
VT, Custom);
setOperationAction({ISD::VP_LOAD, ISD::VP_STORE,
ISD::EXPERIMENTAL_VP_STRIDED_LOAD,
ISD::EXPERIMENTAL_VP_STRIDED_STORE, ISD::VP_GATHER,
ISD::VP_SCATTER},
VT, Custom);
setOperationAction({ISD::FADD, ISD::FSUB, ISD::FMUL, ISD::FDIV,
ISD::FNEG, ISD::FABS, ISD::FCOPYSIGN, ISD::FSQRT,
ISD::FMA, ISD::FMINNUM, ISD::FMAXNUM},
VT, Custom);
setOperationAction({ISD::FP_ROUND, ISD::FP_EXTEND}, VT, Custom);
setOperationAction({ISD::FTRUNC, ISD::FCEIL, ISD::FFLOOR, ISD::FROUND,
ISD::FROUNDEVEN},
VT, Custom);
setCondCodeAction(VFPCCToExpand, VT, Expand);
setOperationAction({ISD::VSELECT, ISD::SELECT}, VT, Custom);
setOperationAction(ISD::SELECT_CC, VT, Expand);
setOperationAction(ISD::BITCAST, VT, Custom);
setOperationAction(FloatingPointVecReduceOps, VT, Custom);
setOperationAction(FloatingPointVPOps, VT, Custom);
setOperationAction({ISD::STRICT_FP_EXTEND, ISD::STRICT_FP_ROUND}, VT,
Custom);
setOperationAction({ISD::STRICT_FADD, ISD::STRICT_FSUB,
ISD::STRICT_FMUL, ISD::STRICT_FDIV,
ISD::STRICT_FSQRT, ISD::STRICT_FMA},
VT, Custom);
setOperationAction({ISD::STRICT_FSETCC, ISD::STRICT_FSETCCS}, VT,
Custom);
}
// Custom-legalize bitcasts from fixed-length vectors to scalar types.
setOperationAction(ISD::BITCAST, {MVT::i8, MVT::i16, MVT::i32, MVT::i64},
Custom);
if (Subtarget.hasStdExtZfhOrZfhmin())
setOperationAction(ISD::BITCAST, MVT::f16, Custom);
if (Subtarget.hasStdExtF())
setOperationAction(ISD::BITCAST, MVT::f32, Custom);
if (Subtarget.hasStdExtD())
setOperationAction(ISD::BITCAST, MVT::f64, Custom);
}
}
if (Subtarget.hasForcedAtomics()) {
// Set atomic rmw/cas operations to expand to force __sync libcalls.
setOperationAction(
{ISD::ATOMIC_CMP_SWAP, ISD::ATOMIC_SWAP, ISD::ATOMIC_LOAD_ADD,
ISD::ATOMIC_LOAD_SUB, ISD::ATOMIC_LOAD_AND, ISD::ATOMIC_LOAD_OR,
ISD::ATOMIC_LOAD_XOR, ISD::ATOMIC_LOAD_NAND, ISD::ATOMIC_LOAD_MIN,
ISD::ATOMIC_LOAD_MAX, ISD::ATOMIC_LOAD_UMIN, ISD::ATOMIC_LOAD_UMAX},
XLenVT, Expand);
}
if (Subtarget.hasVendorXTHeadMemIdx()) {
for (unsigned im = (unsigned)ISD::PRE_INC; im != (unsigned)ISD::POST_DEC;
++im) {
setIndexedLoadAction(im, MVT::i8, Legal);
setIndexedStoreAction(im, MVT::i8, Legal);
setIndexedLoadAction(im, MVT::i16, Legal);
setIndexedStoreAction(im, MVT::i16, Legal);
setIndexedLoadAction(im, MVT::i32, Legal);
setIndexedStoreAction(im, MVT::i32, Legal);
if (Subtarget.is64Bit()) {
setIndexedLoadAction(im, MVT::i64, Legal);
setIndexedStoreAction(im, MVT::i64, Legal);
}
}
}
// Function alignments.
const Align FunctionAlignment(Subtarget.hasStdExtCOrZca() ? 2 : 4);
setMinFunctionAlignment(FunctionAlignment);
// Set preferred alignments.
setPrefFunctionAlignment(Subtarget.getPrefFunctionAlignment());
setPrefLoopAlignment(Subtarget.getPrefLoopAlignment());
setMinimumJumpTableEntries(5);
// Jumps are expensive, compared to logic
setJumpIsExpensive();
setTargetDAGCombine({ISD::INTRINSIC_WO_CHAIN, ISD::ADD, ISD::SUB, ISD::AND,
ISD::OR, ISD::XOR, ISD::SETCC, ISD::SELECT});
if (Subtarget.is64Bit())
setTargetDAGCombine(ISD::SRA);
if (Subtarget.hasStdExtF())
setTargetDAGCombine({ISD::FADD, ISD::FMAXNUM, ISD::FMINNUM});
if (Subtarget.hasStdExtZbb())
setTargetDAGCombine({ISD::UMAX, ISD::UMIN, ISD::SMAX, ISD::SMIN});
if (Subtarget.hasStdExtZbs() && Subtarget.is64Bit())
setTargetDAGCombine(ISD::TRUNCATE);
if (Subtarget.hasStdExtZbkb())
setTargetDAGCombine(ISD::BITREVERSE);
if (Subtarget.hasStdExtZfhOrZfhmin())
setTargetDAGCombine(ISD::SIGN_EXTEND_INREG);
if (Subtarget.hasStdExtF())
setTargetDAGCombine({ISD::ZERO_EXTEND, ISD::FP_TO_SINT, ISD::FP_TO_UINT,
ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT});
if (Subtarget.hasVInstructions())
setTargetDAGCombine({ISD::FCOPYSIGN, ISD::MGATHER, ISD::MSCATTER,
ISD::VP_GATHER, ISD::VP_SCATTER, ISD::SRA, ISD::SRL,
ISD::SHL, ISD::STORE, ISD::SPLAT_VECTOR});
if (Subtarget.hasVendorXTHeadMemPair())
setTargetDAGCombine({ISD::LOAD, ISD::STORE});
if (Subtarget.useRVVForFixedLengthVectors())
setTargetDAGCombine(ISD::BITCAST);
setLibcallName(RTLIB::FPEXT_F16_F32, "__extendhfsf2");
setLibcallName(RTLIB::FPROUND_F32_F16, "__truncsfhf2");
}
EVT RISCVTargetLowering::getSetCCResultType(const DataLayout &DL,
LLVMContext &Context,
EVT VT) const {
if (!VT.isVector())
return getPointerTy(DL);
if (Subtarget.hasVInstructions() &&
(VT.isScalableVector() || Subtarget.useRVVForFixedLengthVectors()))
return EVT::getVectorVT(Context, MVT::i1, VT.getVectorElementCount());
return VT.changeVectorElementTypeToInteger();
}
MVT RISCVTargetLowering::getVPExplicitVectorLengthTy() const {
return Subtarget.getXLenVT();
}
bool RISCVTargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info,
const CallInst &I,
MachineFunction &MF,
unsigned Intrinsic) const {
auto &DL = I.getModule()->getDataLayout();
auto SetRVVLoadStoreInfo = [&](unsigned PtrOp, bool IsStore,
bool IsUnitStrided) {
Info.opc = IsStore ? ISD::INTRINSIC_VOID : ISD::INTRINSIC_W_CHAIN;
Info.ptrVal = I.getArgOperand(PtrOp);
Type *MemTy;
if (IsStore) {
// Store value is the first operand.
MemTy = I.getArgOperand(0)->getType();
} else {
// Use return type. If it's segment load, return type is a struct.
MemTy = I.getType();
if (MemTy->isStructTy())
MemTy = MemTy->getStructElementType(0);
}
if (!IsUnitStrided)
MemTy = MemTy->getScalarType();
Info.memVT = getValueType(DL, MemTy);
Info.align = Align(DL.getTypeSizeInBits(MemTy->getScalarType()) / 8);
Info.size = MemoryLocation::UnknownSize;
Info.flags |=
IsStore ? MachineMemOperand::MOStore : MachineMemOperand::MOLoad;
return true;
};
if (I.getMetadata(LLVMContext::MD_nontemporal) != nullptr)
Info.flags |= MachineMemOperand::MONonTemporal;
Info.flags |= RISCVTargetLowering::getTargetMMOFlags(I);
switch (Intrinsic) {
default:
return false;
case Intrinsic::riscv_masked_atomicrmw_xchg_i32:
case Intrinsic::riscv_masked_atomicrmw_add_i32:
case Intrinsic::riscv_masked_atomicrmw_sub_i32:
case Intrinsic::riscv_masked_atomicrmw_nand_i32:
case Intrinsic::riscv_masked_atomicrmw_max_i32:
case Intrinsic::riscv_masked_atomicrmw_min_i32:
case Intrinsic::riscv_masked_atomicrmw_umax_i32:
case Intrinsic::riscv_masked_atomicrmw_umin_i32:
case Intrinsic::riscv_masked_cmpxchg_i32:
Info.opc = ISD::INTRINSIC_W_CHAIN;
Info.memVT = MVT::i32;
Info.ptrVal = I.getArgOperand(0);
Info.offset = 0;
Info.align = Align(4);
Info.flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore |
MachineMemOperand::MOVolatile;
return true;
case Intrinsic::riscv_masked_strided_load:
return SetRVVLoadStoreInfo(/*PtrOp*/ 1, /*IsStore*/ false,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_masked_strided_store:
return SetRVVLoadStoreInfo(/*PtrOp*/ 1, /*IsStore*/ true,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_seg2_load:
case Intrinsic::riscv_seg3_load:
case Intrinsic::riscv_seg4_load:
case Intrinsic::riscv_seg5_load:
case Intrinsic::riscv_seg6_load:
case Intrinsic::riscv_seg7_load:
case Intrinsic::riscv_seg8_load:
return SetRVVLoadStoreInfo(/*PtrOp*/ 0, /*IsStore*/ false,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_seg2_store:
case Intrinsic::riscv_seg3_store:
case Intrinsic::riscv_seg4_store:
case Intrinsic::riscv_seg5_store:
case Intrinsic::riscv_seg6_store:
case Intrinsic::riscv_seg7_store:
case Intrinsic::riscv_seg8_store:
// Operands are (vec, ..., vec, ptr, vl)
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 2,
/*IsStore*/ true,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vle:
case Intrinsic::riscv_vle_mask:
case Intrinsic::riscv_vleff:
case Intrinsic::riscv_vleff_mask:
return SetRVVLoadStoreInfo(/*PtrOp*/ 1,
/*IsStore*/ false,
/*IsUnitStrided*/ true);
case Intrinsic::riscv_vse:
case Intrinsic::riscv_vse_mask:
return SetRVVLoadStoreInfo(/*PtrOp*/ 1,
/*IsStore*/ true,
/*IsUnitStrided*/ true);
case Intrinsic::riscv_vlse:
case Intrinsic::riscv_vlse_mask:
case Intrinsic::riscv_vloxei:
case Intrinsic::riscv_vloxei_mask:
case Intrinsic::riscv_vluxei:
case Intrinsic::riscv_vluxei_mask:
return SetRVVLoadStoreInfo(/*PtrOp*/ 1,
/*IsStore*/ false,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vsse:
case Intrinsic::riscv_vsse_mask:
case Intrinsic::riscv_vsoxei:
case Intrinsic::riscv_vsuxei:
return SetRVVLoadStoreInfo(/*PtrOp*/ 1,
/*IsStore*/ true,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vlseg2:
case Intrinsic::riscv_vlseg3:
case Intrinsic::riscv_vlseg4:
case Intrinsic::riscv_vlseg5:
case Intrinsic::riscv_vlseg6:
case Intrinsic::riscv_vlseg7:
case Intrinsic::riscv_vlseg8:
case Intrinsic::riscv_vlseg2ff:
case Intrinsic::riscv_vlseg3ff:
case Intrinsic::riscv_vlseg4ff:
case Intrinsic::riscv_vlseg5ff:
case Intrinsic::riscv_vlseg6ff:
case Intrinsic::riscv_vlseg7ff:
case Intrinsic::riscv_vlseg8ff:
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 2,
/*IsStore*/ false,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vlseg2_mask:
case Intrinsic::riscv_vlseg3_mask:
case Intrinsic::riscv_vlseg4_mask:
case Intrinsic::riscv_vlseg5_mask:
case Intrinsic::riscv_vlseg6_mask:
case Intrinsic::riscv_vlseg7_mask:
case Intrinsic::riscv_vlseg8_mask:
case Intrinsic::riscv_vlseg2ff_mask:
case Intrinsic::riscv_vlseg3ff_mask:
case Intrinsic::riscv_vlseg4ff_mask:
case Intrinsic::riscv_vlseg5ff_mask:
case Intrinsic::riscv_vlseg6ff_mask:
case Intrinsic::riscv_vlseg7ff_mask:
case Intrinsic::riscv_vlseg8ff_mask:
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 4,
/*IsStore*/ false,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vlsseg2:
case Intrinsic::riscv_vlsseg3:
case Intrinsic::riscv_vlsseg4:
case Intrinsic::riscv_vlsseg5:
case Intrinsic::riscv_vlsseg6:
case Intrinsic::riscv_vlsseg7:
case Intrinsic::riscv_vlsseg8:
case Intrinsic::riscv_vloxseg2:
case Intrinsic::riscv_vloxseg3:
case Intrinsic::riscv_vloxseg4:
case Intrinsic::riscv_vloxseg5:
case Intrinsic::riscv_vloxseg6:
case Intrinsic::riscv_vloxseg7:
case Intrinsic::riscv_vloxseg8:
case Intrinsic::riscv_vluxseg2:
case Intrinsic::riscv_vluxseg3:
case Intrinsic::riscv_vluxseg4:
case Intrinsic::riscv_vluxseg5:
case Intrinsic::riscv_vluxseg6:
case Intrinsic::riscv_vluxseg7:
case Intrinsic::riscv_vluxseg8:
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 3,
/*IsStore*/ false,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vlsseg2_mask:
case Intrinsic::riscv_vlsseg3_mask:
case Intrinsic::riscv_vlsseg4_mask:
case Intrinsic::riscv_vlsseg5_mask:
case Intrinsic::riscv_vlsseg6_mask:
case Intrinsic::riscv_vlsseg7_mask:
case Intrinsic::riscv_vlsseg8_mask:
case Intrinsic::riscv_vloxseg2_mask:
case Intrinsic::riscv_vloxseg3_mask:
case Intrinsic::riscv_vloxseg4_mask:
case Intrinsic::riscv_vloxseg5_mask:
case Intrinsic::riscv_vloxseg6_mask:
case Intrinsic::riscv_vloxseg7_mask:
case Intrinsic::riscv_vloxseg8_mask:
case Intrinsic::riscv_vluxseg2_mask:
case Intrinsic::riscv_vluxseg3_mask:
case Intrinsic::riscv_vluxseg4_mask:
case Intrinsic::riscv_vluxseg5_mask:
case Intrinsic::riscv_vluxseg6_mask:
case Intrinsic::riscv_vluxseg7_mask:
case Intrinsic::riscv_vluxseg8_mask:
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 5,
/*IsStore*/ false,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vsseg2:
case Intrinsic::riscv_vsseg3:
case Intrinsic::riscv_vsseg4:
case Intrinsic::riscv_vsseg5:
case Intrinsic::riscv_vsseg6:
case Intrinsic::riscv_vsseg7:
case Intrinsic::riscv_vsseg8:
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 2,
/*IsStore*/ true,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vsseg2_mask:
case Intrinsic::riscv_vsseg3_mask:
case Intrinsic::riscv_vsseg4_mask:
case Intrinsic::riscv_vsseg5_mask:
case Intrinsic::riscv_vsseg6_mask:
case Intrinsic::riscv_vsseg7_mask:
case Intrinsic::riscv_vsseg8_mask:
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 3,
/*IsStore*/ true,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vssseg2:
case Intrinsic::riscv_vssseg3:
case Intrinsic::riscv_vssseg4:
case Intrinsic::riscv_vssseg5:
case Intrinsic::riscv_vssseg6:
case Intrinsic::riscv_vssseg7:
case Intrinsic::riscv_vssseg8:
case Intrinsic::riscv_vsoxseg2:
case Intrinsic::riscv_vsoxseg3:
case Intrinsic::riscv_vsoxseg4:
case Intrinsic::riscv_vsoxseg5:
case Intrinsic::riscv_vsoxseg6:
case Intrinsic::riscv_vsoxseg7:
case Intrinsic::riscv_vsoxseg8:
case Intrinsic::riscv_vsuxseg2:
case Intrinsic::riscv_vsuxseg3:
case Intrinsic::riscv_vsuxseg4:
case Intrinsic::riscv_vsuxseg5:
case Intrinsic::riscv_vsuxseg6:
case Intrinsic::riscv_vsuxseg7:
case Intrinsic::riscv_vsuxseg8:
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 3,
/*IsStore*/ true,
/*IsUnitStrided*/ false);
case Intrinsic::riscv_vssseg2_mask:
case Intrinsic::riscv_vssseg3_mask:
case Intrinsic::riscv_vssseg4_mask:
case Intrinsic::riscv_vssseg5_mask:
case Intrinsic::riscv_vssseg6_mask:
case Intrinsic::riscv_vssseg7_mask:
case Intrinsic::riscv_vssseg8_mask:
case Intrinsic::riscv_vsoxseg2_mask:
case Intrinsic::riscv_vsoxseg3_mask:
case Intrinsic::riscv_vsoxseg4_mask:
case Intrinsic::riscv_vsoxseg5_mask:
case Intrinsic::riscv_vsoxseg6_mask:
case Intrinsic::riscv_vsoxseg7_mask:
case Intrinsic::riscv_vsoxseg8_mask:
case Intrinsic::riscv_vsuxseg2_mask:
case Intrinsic::riscv_vsuxseg3_mask:
case Intrinsic::riscv_vsuxseg4_mask:
case Intrinsic::riscv_vsuxseg5_mask:
case Intrinsic::riscv_vsuxseg6_mask:
case Intrinsic::riscv_vsuxseg7_mask:
case Intrinsic::riscv_vsuxseg8_mask:
return SetRVVLoadStoreInfo(/*PtrOp*/ I.arg_size() - 4,
/*IsStore*/ true,
/*IsUnitStrided*/ false);
}
}
bool RISCVTargetLowering::isLegalAddressingMode(const DataLayout &DL,
const AddrMode &AM, Type *Ty,
unsigned AS,
Instruction *I) const {
// No global is ever allowed as a base.
if (AM.BaseGV)
return false;
// RVV instructions only support register addressing.
if (Subtarget.hasVInstructions() && isa<VectorType>(Ty))
return AM.HasBaseReg && AM.Scale == 0 && !AM.BaseOffs;
// Require a 12-bit signed offset.
if (!isInt<12>(AM.BaseOffs))
return false;
switch (AM.Scale) {
case 0: // "r+i" or just "i", depending on HasBaseReg.
break;
case 1:
if (!AM.HasBaseReg) // allow "r+i".
break;
return false; // disallow "r+r" or "r+r+i".
default:
return false;
}
return true;
}
bool RISCVTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
return isInt<12>(Imm);
}
bool RISCVTargetLowering::isLegalAddImmediate(int64_t Imm) const {
return isInt<12>(Imm);
}
// On RV32, 64-bit integers are split into their high and low parts and held
// in two different registers, so the trunc is free since the low register can
// just be used.
// FIXME: Should we consider i64->i32 free on RV64 to match the EVT version of
// isTruncateFree?
bool RISCVTargetLowering::isTruncateFree(Type *SrcTy, Type *DstTy) const {
if (Subtarget.is64Bit() || !SrcTy->isIntegerTy() || !DstTy->isIntegerTy())
return false;
unsigned SrcBits = SrcTy->getPrimitiveSizeInBits();
unsigned DestBits = DstTy->getPrimitiveSizeInBits();
return (SrcBits == 64 && DestBits == 32);
}
bool RISCVTargetLowering::isTruncateFree(EVT SrcVT, EVT DstVT) const {
// We consider i64->i32 free on RV64 since we have good selection of W
// instructions that make promoting operations back to i64 free in many cases.
if (SrcVT.isVector() || DstVT.isVector() || !SrcVT.isInteger() ||
!DstVT.isInteger())
return false;
unsigned SrcBits = SrcVT.getSizeInBits();
unsigned DestBits = DstVT.getSizeInBits();
return (SrcBits == 64 && DestBits == 32);
}
bool RISCVTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
// Zexts are free if they can be combined with a load.
// Don't advertise i32->i64 zextload as being free for RV64. It interacts
// poorly with type legalization of compares preferring sext.
if (auto *LD = dyn_cast<LoadSDNode>(Val)) {
EVT MemVT = LD->getMemoryVT();
if ((MemVT == MVT::i8 || MemVT == MVT::i16) &&
(LD->getExtensionType() == ISD::NON_EXTLOAD ||
LD->getExtensionType() == ISD::ZEXTLOAD))
return true;
}
return TargetLowering::isZExtFree(Val, VT2);
}
bool RISCVTargetLowering::isSExtCheaperThanZExt(EVT SrcVT, EVT DstVT) const {
return Subtarget.is64Bit() && SrcVT == MVT::i32 && DstVT == MVT::i64;
}
bool RISCVTargetLowering::signExtendConstant(const ConstantInt *CI) const {
return Subtarget.is64Bit() && CI->getType()->isIntegerTy(32);
}
bool RISCVTargetLowering::isCheapToSpeculateCttz(Type *Ty) const {
return Subtarget.hasStdExtZbb();
}
bool RISCVTargetLowering::isCheapToSpeculateCtlz(Type *Ty) const {
return Subtarget.hasStdExtZbb() || Subtarget.hasVendorXTHeadBb();
}
bool RISCVTargetLowering::isMaskAndCmp0FoldingBeneficial(
const Instruction &AndI) const {
// We expect to be able to match a bit extraction instruction if the Zbs
// extension is supported and the mask is a power of two. However, we
// conservatively return false if the mask would fit in an ANDI instruction,
// on the basis that it's possible the sinking+duplication of the AND in
// CodeGenPrepare triggered by this hook wouldn't decrease the instruction
// count and would increase code size (e.g. ANDI+BNEZ => BEXTI+BNEZ).
if (!Subtarget.hasStdExtZbs() && !Subtarget.hasVendorXTHeadBs())
return false;
ConstantInt *Mask = dyn_cast<ConstantInt>(AndI.getOperand(1));
if (!Mask)
return false;
return !Mask->getValue().isSignedIntN(12) && Mask->getValue().isPowerOf2();
}
bool RISCVTargetLowering::hasAndNotCompare(SDValue Y) const {
EVT VT = Y.getValueType();
// FIXME: Support vectors once we have tests.
if (VT.isVector())
return false;
return (Subtarget.hasStdExtZbb() || Subtarget.hasStdExtZbkb()) &&
!isa<ConstantSDNode>(Y);
}
bool RISCVTargetLowering::hasBitTest(SDValue X, SDValue Y) const {
// Zbs provides BEXT[_I], which can be used with SEQZ/SNEZ as a bit test.
if (Subtarget.hasStdExtZbs())
return X.getValueType().isScalarInteger();
auto *C = dyn_cast<ConstantSDNode>(Y);
// XTheadBs provides th.tst (similar to bexti), if Y is a constant
if (Subtarget.hasVendorXTHeadBs())
return C != nullptr;
// We can use ANDI+SEQZ/SNEZ as a bit test. Y contains the bit position.
return C && C->getAPIntValue().ule(10);
}
bool RISCVTargetLowering::shouldFoldSelectWithIdentityConstant(unsigned Opcode,
EVT VT) const {
// Only enable for rvv.
if (!VT.isVector() || !Subtarget.hasVInstructions())
return false;
if (VT.isFixedLengthVector() && !isTypeLegal(VT))
return false;
return true;
}
bool RISCVTargetLowering::shouldConvertConstantLoadToIntImm(const APInt &Imm,
Type *Ty) const {
assert(Ty->isIntegerTy());
unsigned BitSize = Ty->getIntegerBitWidth();
if (BitSize > Subtarget.getXLen())
return false;
// Fast path, assume 32-bit immediates are cheap.
int64_t Val = Imm.getSExtValue();
if (isInt<32>(Val))
return true;
// A constant pool entry may be more aligned thant he load we're trying to
// replace. If we don't support unaligned scalar mem, prefer the constant
// pool.
// TODO: Can the caller pass down the alignment?
if (!Subtarget.enableUnalignedScalarMem())
return true;
// Prefer to keep the load if it would require many instructions.
// This uses the same threshold we use for constant pools but doesn't
// check useConstantPoolForLargeInts.
// TODO: Should we keep the load only when we're definitely going to emit a
// constant pool?
RISCVMatInt::InstSeq Seq =
RISCVMatInt::generateInstSeq(Val, Subtarget.getFeatureBits());
return Seq.size() <= Subtarget.getMaxBuildIntsCost();
}
bool RISCVTargetLowering::
shouldProduceAndByConstByHoistingConstFromShiftsLHSOfAnd(
SDValue X, ConstantSDNode *XC, ConstantSDNode *CC, SDValue Y,
unsigned OldShiftOpcode, unsigned NewShiftOpcode,
SelectionDAG &DAG) const {
// One interesting pattern that we'd want to form is 'bit extract':
// ((1 >> Y) & 1) ==/!= 0
// But we also need to be careful not to try to reverse that fold.
// Is this '((1 >> Y) & 1)'?
if (XC && OldShiftOpcode == ISD::SRL && XC->isOne())
return false; // Keep the 'bit extract' pattern.
// Will this be '((1 >> Y) & 1)' after the transform?
if (NewShiftOpcode == ISD::SRL && CC->isOne())
return true; // Do form the 'bit extract' pattern.
// If 'X' is a constant, and we transform, then we will immediately
// try to undo the fold, thus causing endless combine loop.
// So only do the transform if X is not a constant. This matches the default
// implementation of this function.
return !XC;
}
bool RISCVTargetLowering::canSplatOperand(unsigned Opcode, int Operand) const {
switch (Opcode) {
case Instruction::Add:
case Instruction::Sub:
case Instruction::Mul:
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
case Instruction::FAdd:
case Instruction::FSub:
case Instruction::FMul:
case Instruction::FDiv:
case Instruction::ICmp:
case Instruction::FCmp:
return true;
case Instruction::Shl:
case Instruction::LShr:
case Instruction::AShr:
case Instruction::UDiv:
case Instruction::SDiv:
case Instruction::URem:
case Instruction::SRem:
return Operand == 1;
default:
return false;
}
}
bool RISCVTargetLowering::canSplatOperand(Instruction *I, int Operand) const {
if (!I->getType()->isVectorTy() || !Subtarget.hasVInstructions())
return false;
if (canSplatOperand(I->getOpcode(), Operand))
return true;
auto *II = dyn_cast<IntrinsicInst>(I);
if (!II)
return false;
switch (II->getIntrinsicID()) {
case Intrinsic::fma:
case Intrinsic::vp_fma:
return Operand == 0 || Operand == 1;
case Intrinsic::vp_shl:
case Intrinsic::vp_lshr:
case Intrinsic::vp_ashr:
case Intrinsic::vp_udiv:
case Intrinsic::vp_sdiv:
case Intrinsic::vp_urem:
case Intrinsic::vp_srem:
return Operand == 1;
// These intrinsics are commutative.
case Intrinsic::vp_add:
case Intrinsic::vp_mul:
case Intrinsic::vp_and:
case Intrinsic::vp_or:
case Intrinsic::vp_xor:
case Intrinsic::vp_fadd:
case Intrinsic::vp_fmul:
// These intrinsics have 'vr' versions.
case Intrinsic::vp_sub:
case Intrinsic::vp_fsub:
case Intrinsic::vp_fdiv:
return Operand == 0 || Operand == 1;
default:
return false;
}
}
/// Check if sinking \p I's operands to I's basic block is profitable, because
/// the operands can be folded into a target instruction, e.g.
/// splats of scalars can fold into vector instructions.
bool RISCVTargetLowering::shouldSinkOperands(
Instruction *I, SmallVectorImpl<Use *> &Ops) const {
using namespace llvm::PatternMatch;
if (!I->getType()->isVectorTy() || !Subtarget.hasVInstructions())
return false;
for (auto OpIdx : enumerate(I->operands())) {
if (!canSplatOperand(I, OpIdx.index()))
continue;
Instruction *Op = dyn_cast<Instruction>(OpIdx.value().get());
// Make sure we are not already sinking this operand
if (!Op || any_of(Ops, [&](Use *U) { return U->get() == Op; }))
continue;
// We are looking for a splat that can be sunk.
if (!match(Op, m_Shuffle(m_InsertElt(m_Undef(), m_Value(), m_ZeroInt()),
m_Undef(), m_ZeroMask())))
continue;
// All uses of the shuffle should be sunk to avoid duplicating it across gpr
// and vector registers
for (Use &U : Op->uses()) {
Instruction *Insn = cast<Instruction>(U.getUser());
if (!canSplatOperand(Insn, U.getOperandNo()))
return false;
}
Ops.push_back(&Op->getOperandUse(0));
Ops.push_back(&OpIdx.value());
}
return true;
}
bool RISCVTargetLowering::shouldScalarizeBinop(SDValue VecOp) const {
unsigned Opc = VecOp.getOpcode();
// Assume target opcodes can't be scalarized.
// TODO - do we have any exceptions?
if (Opc >= ISD::BUILTIN_OP_END)
return false;
// If the vector op is not supported, try to convert to scalar.
EVT VecVT = VecOp.getValueType();
if (!isOperationLegalOrCustomOrPromote(Opc, VecVT))
return true;
// If the vector op is supported, but the scalar op is not, the transform may
// not be worthwhile.
EVT ScalarVT = VecVT.getScalarType();
return isOperationLegalOrCustomOrPromote(Opc, ScalarVT);
}
bool RISCVTargetLowering::isOffsetFoldingLegal(
const GlobalAddressSDNode *GA) const {
// In order to maximise the opportunity for common subexpression elimination,
// keep a separate ADD node for the global address offset instead of folding
// it in the global address node. Later peephole optimisations may choose to
// fold it back in when profitable.
return false;
}
// Returns 0-31 if the fli instruction is available for the type and this is
// legal FP immediate for the type. Returns -1 otherwise.
int RISCVTargetLowering::getLegalZfaFPImm(const APFloat &Imm, EVT VT) const {
if (!Subtarget.hasStdExtZfa())
return -1;
bool IsSupportedVT = false;
if (VT == MVT::f16) {
IsSupportedVT = Subtarget.hasStdExtZfh() || Subtarget.hasStdExtZvfh();
} else if (VT == MVT::f32) {
IsSupportedVT = true;
} else if (VT == MVT::f64) {
assert(Subtarget.hasStdExtD() && "Expect D extension");
IsSupportedVT = true;
}
if (!IsSupportedVT)
return -1;
return RISCVLoadFPImm::getLoadFPImm(Imm);
}
bool RISCVTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
bool ForCodeSize) const {
bool IsLegalVT = false;
if (VT == MVT::f16)
IsLegalVT = Subtarget.hasStdExtZfhOrZfhmin();
else if (VT == MVT::f32)
IsLegalVT = Subtarget.hasStdExtF();
else if (VT == MVT::f64)
IsLegalVT = Subtarget.hasStdExtD();
if (!IsLegalVT)
return false;
if (getLegalZfaFPImm(Imm, VT) >= 0)
return true;
// Cannot create a 64 bit floating-point immediate value for rv32.
if (Subtarget.getXLen() < VT.getScalarSizeInBits()) {
// td can handle +0.0 or -0.0 already.
// -0.0 can be created by fmv + fneg.
return Imm.isZero();
}
// Special case: the cost for -0.0 is 1.
int Cost = Imm.isNegZero()
? 1
: RISCVMatInt::getIntMatCost(Imm.bitcastToAPInt(),
Subtarget.getXLen(),
Subtarget.getFeatureBits());
// If the constantpool data is already in cache, only Cost 1 is cheaper.
return Cost < FPImmCost;
}
// TODO: This is very conservative.
bool RISCVTargetLowering::isExtractSubvectorCheap(EVT ResVT, EVT SrcVT,
unsigned Index) const {
if (!isOperationLegalOrCustom(ISD::EXTRACT_SUBVECTOR, ResVT))
return false;
// Only support extracting a fixed from a fixed vector for now.
if (ResVT.isScalableVector() || SrcVT.isScalableVector())
return false;
unsigned ResElts = ResVT.getVectorNumElements();
unsigned SrcElts = SrcVT.getVectorNumElements();
// Convervatively only handle extracting half of a vector.
// TODO: Relax this.
if ((ResElts * 2) != SrcElts)
return false;
// The smallest type we can slide is i8.
// TODO: We can extract index 0 from a mask vector without a slide.
if (ResVT.getVectorElementType() == MVT::i1)
return false;
// Slide can support arbitrary index, but we only treat vslidedown.vi as
// cheap.
if (Index >= 32)
return false;
// TODO: We can do arbitrary slidedowns, but for now only support extracting
// the upper half of a vector until we have more test coverage.
return Index == 0 || Index == ResElts;
}
MVT RISCVTargetLowering::getRegisterTypeForCallingConv(LLVMContext &Context,
CallingConv::ID CC,
EVT VT) const {
// Use f32 to pass f16 if it is legal and Zfh/Zfhmin is not enabled.
// We might still end up using a GPR but that will be decided based on ABI.
if (VT == MVT::f16 && Subtarget.hasStdExtF() &&
!Subtarget.hasStdExtZfhOrZfhmin())
return MVT::f32;
return TargetLowering::getRegisterTypeForCallingConv(Context, CC, VT);
}
unsigned RISCVTargetLowering::getNumRegistersForCallingConv(LLVMContext &Context,
CallingConv::ID CC,
EVT VT) const {
// Use f32 to pass f16 if it is legal and Zfh/Zfhmin is not enabled.
// We might still end up using a GPR but that will be decided based on ABI.
if (VT == MVT::f16 && Subtarget.hasStdExtF() &&
!Subtarget.hasStdExtZfhOrZfhmin())
return 1;
return TargetLowering::getNumRegistersForCallingConv(Context, CC, VT);
}
// Changes the condition code and swaps operands if necessary, so the SetCC
// operation matches one of the comparisons supported directly by branches
// in the RISC-V ISA. May adjust compares to favor compare with 0 over compare
// with 1/-1.
static void translateSetCCForBranch(const SDLoc &DL, SDValue &LHS, SDValue &RHS,
ISD::CondCode &CC, SelectionDAG &DAG) {
// If this is a single bit test that can't be handled by ANDI, shift the
// bit to be tested to the MSB and perform a signed compare with 0.
if (isIntEqualitySetCC(CC) && isNullConstant(RHS) &&
LHS.getOpcode() == ISD::AND && LHS.hasOneUse() &&
isa<ConstantSDNode>(LHS.getOperand(1))) {
uint64_t Mask = LHS.getConstantOperandVal(1);
if ((isPowerOf2_64(Mask) || isMask_64(Mask)) && !isInt<12>(Mask)) {
unsigned ShAmt = 0;
if (isPowerOf2_64(Mask)) {
CC = CC == ISD::SETEQ ? ISD::SETGE : ISD::SETLT;
ShAmt = LHS.getValueSizeInBits() - 1 - Log2_64(Mask);
} else {
ShAmt = LHS.getValueSizeInBits() - llvm::bit_width(Mask);
}
LHS = LHS.getOperand(0);
if (ShAmt != 0)
LHS = DAG.getNode(ISD::SHL, DL, LHS.getValueType(), LHS,
DAG.getConstant(ShAmt, DL, LHS.getValueType()));
return;
}
}
if (auto *RHSC = dyn_cast<ConstantSDNode>(RHS)) {
int64_t C = RHSC->getSExtValue();
switch (CC) {
default: break;
case ISD::SETGT:
// Convert X > -1 to X >= 0.
if (C == -1) {
RHS = DAG.getConstant(0, DL, RHS.getValueType());
CC = ISD::SETGE;
return;
}
break;
case ISD::SETLT:
// Convert X < 1 to 0 <= X.
if (C == 1) {
RHS = LHS;
LHS = DAG.getConstant(0, DL, RHS.getValueType());
CC = ISD::SETGE;
return;
}
break;
}
}
switch (CC) {
default:
break;
case ISD::SETGT:
case ISD::SETLE:
case ISD::SETUGT:
case ISD::SETULE:
CC = ISD::getSetCCSwappedOperands(CC);
std::swap(LHS, RHS);
break;
}
}
RISCVII::VLMUL RISCVTargetLowering::getLMUL(MVT VT) {
assert(VT.isScalableVector() && "Expecting a scalable vector type");
unsigned KnownSize = VT.getSizeInBits().getKnownMinValue();
if (VT.getVectorElementType() == MVT::i1)
KnownSize *= 8;
switch (KnownSize) {
default:
llvm_unreachable("Invalid LMUL.");
case 8:
return RISCVII::VLMUL::LMUL_F8;
case 16:
return RISCVII::VLMUL::LMUL_F4;
case 32:
return RISCVII::VLMUL::LMUL_F2;
case 64:
return RISCVII::VLMUL::LMUL_1;
case 128:
return RISCVII::VLMUL::LMUL_2;
case 256:
return RISCVII::VLMUL::LMUL_4;
case 512:
return RISCVII::VLMUL::LMUL_8;
}
}
unsigned RISCVTargetLowering::getRegClassIDForLMUL(RISCVII::VLMUL LMul) {
switch (LMul) {
default:
llvm_unreachable("Invalid LMUL.");
case RISCVII::VLMUL::LMUL_F8:
case RISCVII::VLMUL::LMUL_F4:
case RISCVII::VLMUL::LMUL_F2:
case RISCVII::VLMUL::LMUL_1:
return RISCV::VRRegClassID;
case RISCVII::VLMUL::LMUL_2:
return RISCV::VRM2RegClassID;
case RISCVII::VLMUL::LMUL_4:
return RISCV::VRM4RegClassID;
case RISCVII::VLMUL::LMUL_8:
return RISCV::VRM8RegClassID;
}
}
unsigned RISCVTargetLowering::getSubregIndexByMVT(MVT VT, unsigned Index) {
RISCVII::VLMUL LMUL = getLMUL(VT);
if (LMUL == RISCVII::VLMUL::LMUL_F8 ||
LMUL == RISCVII::VLMUL::LMUL_F4 ||
LMUL == RISCVII::VLMUL::LMUL_F2 ||
LMUL == RISCVII::VLMUL::LMUL_1) {
static_assert(RISCV::sub_vrm1_7 == RISCV::sub_vrm1_0 + 7,
"Unexpected subreg numbering");
return RISCV::sub_vrm1_0 + Index;
}
if (LMUL == RISCVII::VLMUL::LMUL_2) {
static_assert(RISCV::sub_vrm2_3 == RISCV::sub_vrm2_0 + 3,
"Unexpected subreg numbering");
return RISCV::sub_vrm2_0 + Index;
}
if (LMUL == RISCVII::VLMUL::LMUL_4) {
static_assert(RISCV::sub_vrm4_1 == RISCV::sub_vrm4_0 + 1,
"Unexpected subreg numbering");
return RISCV::sub_vrm4_0 + Index;
}
llvm_unreachable("Invalid vector type.");
}
unsigned RISCVTargetLowering::getRegClassIDForVecVT(MVT VT) {
if (VT.getVectorElementType() == MVT::i1)
return RISCV::VRRegClassID;
return getRegClassIDForLMUL(getLMUL(VT));
}
// Attempt to decompose a subvector insert/extract between VecVT and
// SubVecVT via subregister indices. Returns the subregister index that
// can perform the subvector insert/extract with the given element index, as
// well as the index corresponding to any leftover subvectors that must be
// further inserted/extracted within the register class for SubVecVT.
std::pair<unsigned, unsigned>
RISCVTargetLowering::decomposeSubvectorInsertExtractToSubRegs(
MVT VecVT, MVT SubVecVT, unsigned InsertExtractIdx,
const RISCVRegisterInfo *TRI) {
static_assert((RISCV::VRM8RegClassID > RISCV::VRM4RegClassID &&
RISCV::VRM4RegClassID > RISCV::VRM2RegClassID &&
RISCV::VRM2RegClassID > RISCV::VRRegClassID),
"Register classes not ordered");
unsigned VecRegClassID = getRegClassIDForVecVT(VecVT);
unsigned SubRegClassID = getRegClassIDForVecVT(SubVecVT);
// Try to compose a subregister index that takes us from the incoming
// LMUL>1 register class down to the outgoing one. At each step we half
// the LMUL:
// nxv16i32@12 -> nxv2i32: sub_vrm4_1_then_sub_vrm2_1_then_sub_vrm1_0
// Note that this is not guaranteed to find a subregister index, such as
// when we are extracting from one VR type to another.
unsigned SubRegIdx = RISCV::NoSubRegister;
for (const unsigned RCID :
{RISCV::VRM4RegClassID, RISCV::VRM2RegClassID, RISCV::VRRegClassID})
if (VecRegClassID > RCID && SubRegClassID <= RCID) {
VecVT = VecVT.getHalfNumVectorElementsVT();
bool IsHi =
InsertExtractIdx >= VecVT.getVectorElementCount().getKnownMinValue();
SubRegIdx = TRI->composeSubRegIndices(SubRegIdx,
getSubregIndexByMVT(VecVT, IsHi));
if (IsHi)
InsertExtractIdx -= VecVT.getVectorElementCount().getKnownMinValue();
}
return {SubRegIdx, InsertExtractIdx};
}
// Permit combining of mask vectors as BUILD_VECTOR never expands to scalar
// stores for those types.
bool RISCVTargetLowering::mergeStoresAfterLegalization(EVT VT) const {
return !Subtarget.useRVVForFixedLengthVectors() ||
(VT.isFixedLengthVector() && VT.getVectorElementType() == MVT::i1);
}
bool RISCVTargetLowering::isLegalElementTypeForRVV(Type *ScalarTy) const {
if (ScalarTy->isPointerTy())
return Subtarget.is64Bit() ? Subtarget.hasVInstructionsI64() : true;
if (ScalarTy->isIntegerTy(8) || ScalarTy->isIntegerTy(16) ||
ScalarTy->isIntegerTy(32))
return true;
if (ScalarTy->isIntegerTy(64))
return Subtarget.hasVInstructionsI64();
if (ScalarTy->isHalfTy())
return Subtarget.hasVInstructionsF16();
if (ScalarTy->isFloatTy())
return Subtarget.hasVInstructionsF32();
if (ScalarTy->isDoubleTy())
return Subtarget.hasVInstructionsF64();
return false;
}
unsigned RISCVTargetLowering::combineRepeatedFPDivisors() const {
return NumRepeatedDivisors;
}
static SDValue getVLOperand(SDValue Op) {
assert((Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_W_CHAIN) &&
"Unexpected opcode");
bool HasChain = Op.getOpcode() == ISD::INTRINSIC_W_CHAIN;
unsigned IntNo = Op.getConstantOperandVal(HasChain ? 1 : 0);
const RISCVVIntrinsicsTable::RISCVVIntrinsicInfo *II =
RISCVVIntrinsicsTable::getRISCVVIntrinsicInfo(IntNo);
if (!II)
return SDValue();
return Op.getOperand(II->VLOperand + 1 + HasChain);
}
static bool useRVVForFixedLengthVectorVT(MVT VT,
const RISCVSubtarget &Subtarget) {
assert(VT.isFixedLengthVector() && "Expected a fixed length vector type!");
if (!Subtarget.useRVVForFixedLengthVectors())
return false;
// We only support a set of vector types with a consistent maximum fixed size
// across all supported vector element types to avoid legalization issues.
// Therefore -- since the largest is v1024i8/v512i16/etc -- the largest
// fixed-length vector type we support is 1024 bytes.
if (VT.getFixedSizeInBits() > 1024 * 8)
return false;
unsigned MinVLen = Subtarget.getRealMinVLen();
MVT EltVT = VT.getVectorElementType();
// Don't use RVV for vectors we cannot scalarize if required.
switch (EltVT.SimpleTy) {
// i1 is supported but has different rules.
default:
return false;
case MVT::i1:
// Masks can only use a single register.
if (VT.getVectorNumElements() > MinVLen)
return false;
MinVLen /= 8;
break;
case MVT::i8:
case MVT::i16:
case MVT::i32:
break;
case MVT::i64:
if (!Subtarget.hasVInstructionsI64())
return false;
break;
case MVT::f16:
if (!Subtarget.hasVInstructionsF16())
return false;
break;
case MVT::f32:
if (!Subtarget.hasVInstructionsF32())
return false;
break;
case MVT::f64:
if (!Subtarget.hasVInstructionsF64())
return false;
break;
}
// Reject elements larger than ELEN.
if (EltVT.getSizeInBits() > Subtarget.getELEN())
return false;
unsigned LMul = divideCeil(VT.getSizeInBits(), MinVLen);
// Don't use RVV for types that don't fit.
if (LMul > Subtarget.getMaxLMULForFixedLengthVectors())
return false;
// TODO: Perhaps an artificial restriction, but worth having whilst getting
// the base fixed length RVV support in place.
if (!VT.isPow2VectorType())
return false;
return true;
}
bool RISCVTargetLowering::useRVVForFixedLengthVectorVT(MVT VT) const {
return ::useRVVForFixedLengthVectorVT(VT, Subtarget);
}
// Return the largest legal scalable vector type that matches VT's element type.
static MVT getContainerForFixedLengthVector(const TargetLowering &TLI, MVT VT,
const RISCVSubtarget &Subtarget) {
// This may be called before legal types are setup.
assert(((VT.isFixedLengthVector() && TLI.isTypeLegal(VT)) ||
useRVVForFixedLengthVectorVT(VT, Subtarget)) &&
"Expected legal fixed length vector!");
unsigned MinVLen = Subtarget.getRealMinVLen();
unsigned MaxELen = Subtarget.getELEN();
MVT EltVT = VT.getVectorElementType();
switch (EltVT.SimpleTy) {
default:
llvm_unreachable("unexpected element type for RVV container");
case MVT::i1:
case MVT::i8:
case MVT::i16:
case MVT::i32:
case MVT::i64:
case MVT::f16:
case MVT::f32:
case MVT::f64: {
// We prefer to use LMUL=1 for VLEN sized types. Use fractional lmuls for
// narrower types. The smallest fractional LMUL we support is 8/ELEN. Within
// each fractional LMUL we support SEW between 8 and LMUL*ELEN.
unsigned NumElts =
(VT.getVectorNumElements() * RISCV::RVVBitsPerBlock) / MinVLen;
NumElts = std::max(NumElts, RISCV::RVVBitsPerBlock / MaxELen);
assert(isPowerOf2_32(NumElts) && "Expected power of 2 NumElts");
return MVT::getScalableVectorVT(EltVT, NumElts);
}
}
}
static MVT getContainerForFixedLengthVector(SelectionDAG &DAG, MVT VT,
const RISCVSubtarget &Subtarget) {
return getContainerForFixedLengthVector(DAG.getTargetLoweringInfo(), VT,
Subtarget);
}
MVT RISCVTargetLowering::getContainerForFixedLengthVector(MVT VT) const {
return ::getContainerForFixedLengthVector(*this, VT, getSubtarget());
}
// Grow V to consume an entire RVV register.
static SDValue convertToScalableVector(EVT VT, SDValue V, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
assert(VT.isScalableVector() &&
"Expected to convert into a scalable vector!");
assert(V.getValueType().isFixedLengthVector() &&
"Expected a fixed length vector operand!");
SDLoc DL(V);
SDValue Zero = DAG.getConstant(0, DL, Subtarget.getXLenVT());
return DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT, DAG.getUNDEF(VT), V, Zero);
}
// Shrink V so it's just big enough to maintain a VT's worth of data.
static SDValue convertFromScalableVector(EVT VT, SDValue V, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
assert(VT.isFixedLengthVector() &&
"Expected to convert into a fixed length vector!");
assert(V.getValueType().isScalableVector() &&
"Expected a scalable vector operand!");
SDLoc DL(V);
SDValue Zero = DAG.getConstant(0, DL, Subtarget.getXLenVT());
return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, V, Zero);
}
/// Return the type of the mask type suitable for masking the provided
/// vector type. This is simply an i1 element type vector of the same
/// (possibly scalable) length.
static MVT getMaskTypeFor(MVT VecVT) {
assert(VecVT.isVector());
ElementCount EC = VecVT.getVectorElementCount();
return MVT::getVectorVT(MVT::i1, EC);
}
/// Creates an all ones mask suitable for masking a vector of type VecTy with
/// vector length VL. .
static SDValue getAllOnesMask(MVT VecVT, SDValue VL, SDLoc DL,
SelectionDAG &DAG) {
MVT MaskVT = getMaskTypeFor(VecVT);
return DAG.getNode(RISCVISD::VMSET_VL, DL, MaskVT, VL);
}
static SDValue getVLOp(uint64_t NumElts, SDLoc DL, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
return DAG.getConstant(NumElts, DL, Subtarget.getXLenVT());
}
static std::pair<SDValue, SDValue>
getDefaultVLOps(uint64_t NumElts, MVT ContainerVT, SDLoc DL, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
assert(ContainerVT.isScalableVector() && "Expecting scalable container type");
SDValue VL = getVLOp(NumElts, DL, DAG, Subtarget);
SDValue Mask = getAllOnesMask(ContainerVT, VL, DL, DAG);
return {Mask, VL};
}
// Gets the two common "VL" operands: an all-ones mask and the vector length.
// VecVT is a vector type, either fixed-length or scalable, and ContainerVT is
// the vector type that the fixed-length vector is contained in. Otherwise if
// VecVT is scalable, then ContainerVT should be the same as VecVT.
static std::pair<SDValue, SDValue>
getDefaultVLOps(MVT VecVT, MVT ContainerVT, SDLoc DL, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
if (VecVT.isFixedLengthVector())
return getDefaultVLOps(VecVT.getVectorNumElements(), ContainerVT, DL, DAG,
Subtarget);
assert(ContainerVT.isScalableVector() && "Expecting scalable container type");
MVT XLenVT = Subtarget.getXLenVT();
SDValue VL = DAG.getRegister(RISCV::X0, XLenVT);
SDValue Mask = getAllOnesMask(ContainerVT, VL, DL, DAG);
return {Mask, VL};
}
// As above but assuming the given type is a scalable vector type.
static std::pair<SDValue, SDValue>
getDefaultScalableVLOps(MVT VecVT, SDLoc DL, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
assert(VecVT.isScalableVector() && "Expecting a scalable vector");
return getDefaultVLOps(VecVT, VecVT, DL, DAG, Subtarget);
}
SDValue RISCVTargetLowering::computeVLMax(MVT VecVT, SDLoc DL,
SelectionDAG &DAG) const {
assert(VecVT.isScalableVector() && "Expected scalable vector");
unsigned MinElts = VecVT.getVectorMinNumElements();
return DAG.getNode(ISD::VSCALE, DL, Subtarget.getXLenVT(),
getVLOp(MinElts, DL, DAG, Subtarget));
}
// The state of RVV BUILD_VECTOR and VECTOR_SHUFFLE lowering is that very few
// of either is (currently) supported. This can get us into an infinite loop
// where we try to lower a BUILD_VECTOR as a VECTOR_SHUFFLE as a BUILD_VECTOR
// as a ..., etc.
// Until either (or both) of these can reliably lower any node, reporting that
// we don't want to expand BUILD_VECTORs via VECTOR_SHUFFLEs at least breaks
// the infinite loop. Note that this lowers BUILD_VECTOR through the stack,
// which is not desirable.
bool RISCVTargetLowering::shouldExpandBuildVectorWithShuffles(
EVT VT, unsigned DefinedValues) const {
return false;
}
static SDValue lowerFP_TO_INT_SAT(SDValue Op, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
// RISC-V FP-to-int conversions saturate to the destination register size, but
// don't produce 0 for nan. We can use a conversion instruction and fix the
// nan case with a compare and a select.
SDValue Src = Op.getOperand(0);
MVT DstVT = Op.getSimpleValueType();
EVT SatVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
bool IsSigned = Op.getOpcode() == ISD::FP_TO_SINT_SAT;
if (!DstVT.isVector()) {
// In absense of Zfh, promote f16 to f32, then saturate the result.
if (Src.getSimpleValueType() == MVT::f16 && !Subtarget.hasStdExtZfh()) {
Src = DAG.getNode(ISD::FP_EXTEND, SDLoc(Op), MVT::f32, Src);
}
unsigned Opc;
if (SatVT == DstVT)
Opc = IsSigned ? RISCVISD::FCVT_X : RISCVISD::FCVT_XU;
else if (DstVT == MVT::i64 && SatVT == MVT::i32)
Opc = IsSigned ? RISCVISD::FCVT_W_RV64 : RISCVISD::FCVT_WU_RV64;
else
return SDValue();
// FIXME: Support other SatVTs by clamping before or after the conversion.
SDLoc DL(Op);
SDValue FpToInt = DAG.getNode(
Opc, DL, DstVT, Src,
DAG.getTargetConstant(RISCVFPRndMode::RTZ, DL, Subtarget.getXLenVT()));
if (Opc == RISCVISD::FCVT_WU_RV64)
FpToInt = DAG.getZeroExtendInReg(FpToInt, DL, MVT::i32);
SDValue ZeroInt = DAG.getConstant(0, DL, DstVT);
return DAG.getSelectCC(DL, Src, Src, ZeroInt, FpToInt,
ISD::CondCode::SETUO);
}
// Vectors.
MVT DstEltVT = DstVT.getVectorElementType();
MVT SrcVT = Src.getSimpleValueType();
MVT SrcEltVT = SrcVT.getVectorElementType();
unsigned SrcEltSize = SrcEltVT.getSizeInBits();
unsigned DstEltSize = DstEltVT.getSizeInBits();
// Only handle saturating to the destination type.
if (SatVT != DstEltVT)
return SDValue();
// FIXME: Don't support narrowing by more than 1 steps for now.
if (SrcEltSize > (2 * DstEltSize))
return SDValue();
MVT DstContainerVT = DstVT;
MVT SrcContainerVT = SrcVT;
if (DstVT.isFixedLengthVector()) {
DstContainerVT = getContainerForFixedLengthVector(DAG, DstVT, Subtarget);
SrcContainerVT = getContainerForFixedLengthVector(DAG, SrcVT, Subtarget);
assert(DstContainerVT.getVectorElementCount() ==
SrcContainerVT.getVectorElementCount() &&
"Expected same element count");
Src = convertToScalableVector(SrcContainerVT, Src, DAG, Subtarget);
}
SDLoc DL(Op);
auto [Mask, VL] = getDefaultVLOps(DstVT, DstContainerVT, DL, DAG, Subtarget);
SDValue IsNan = DAG.getNode(RISCVISD::SETCC_VL, DL, Mask.getValueType(),
{Src, Src, DAG.getCondCode(ISD::SETNE),
DAG.getUNDEF(Mask.getValueType()), Mask, VL});
// Need to widen by more than 1 step, promote the FP type, then do a widening
// convert.
if (DstEltSize > (2 * SrcEltSize)) {
assert(SrcContainerVT.getVectorElementType() == MVT::f16 && "Unexpected VT!");
MVT InterVT = SrcContainerVT.changeVectorElementType(MVT::f32);
Src = DAG.getNode(RISCVISD::FP_EXTEND_VL, DL, InterVT, Src, Mask, VL);
}
unsigned RVVOpc =
IsSigned ? RISCVISD::VFCVT_RTZ_X_F_VL : RISCVISD::VFCVT_RTZ_XU_F_VL;
SDValue Res = DAG.getNode(RVVOpc, DL, DstContainerVT, Src, Mask, VL);
SDValue SplatZero = DAG.getNode(
RISCVISD::VMV_V_X_VL, DL, DstContainerVT, DAG.getUNDEF(DstContainerVT),
DAG.getConstant(0, DL, Subtarget.getXLenVT()), VL);
Res = DAG.getNode(RISCVISD::VSELECT_VL, DL, DstContainerVT, IsNan, SplatZero,
Res, VL);
if (DstVT.isFixedLengthVector())
Res = convertFromScalableVector(DstVT, Res, DAG, Subtarget);
return Res;
}
static RISCVFPRndMode::RoundingMode matchRoundingOp(unsigned Opc) {
switch (Opc) {
case ISD::FROUNDEVEN:
case ISD::VP_FROUNDEVEN:
return RISCVFPRndMode::RNE;
case ISD::FTRUNC:
case ISD::VP_FROUNDTOZERO:
return RISCVFPRndMode::RTZ;
case ISD::FFLOOR:
case ISD::VP_FFLOOR:
return RISCVFPRndMode::RDN;
case ISD::FCEIL:
case ISD::VP_FCEIL:
return RISCVFPRndMode::RUP;
case ISD::FROUND:
case ISD::VP_FROUND:
return RISCVFPRndMode::RMM;
case ISD::FRINT:
return RISCVFPRndMode::DYN;
}
return RISCVFPRndMode::Invalid;
}
// Expand vector FTRUNC, FCEIL, FFLOOR, FROUND, VP_FCEIL, VP_FFLOOR, VP_FROUND
// VP_FROUNDEVEN, VP_FROUNDTOZERO, VP_FRINT and VP_FNEARBYINT by converting to
// the integer domain and back. Taking care to avoid converting values that are
// nan or already correct.
static SDValue
lowerVectorFTRUNC_FCEIL_FFLOOR_FROUND(SDValue Op, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
MVT VT = Op.getSimpleValueType();
assert(VT.isVector() && "Unexpected type");
SDLoc DL(Op);
SDValue Src = Op.getOperand(0);
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(DAG, VT, Subtarget);
Src = convertToScalableVector(ContainerVT, Src, DAG, Subtarget);
}
SDValue Mask, VL;
if (Op->isVPOpcode()) {
Mask = Op.getOperand(1);
VL = Op.getOperand(2);
} else {
std::tie(Mask, VL) = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
}
// Freeze the source since we are increasing the number of uses.
Src = DAG.getFreeze(Src);
// We do the conversion on the absolute value and fix the sign at the end.
SDValue Abs = DAG.getNode(RISCVISD::FABS_VL, DL, ContainerVT, Src, Mask, VL);
// Determine the largest integer that can be represented exactly. This and
// values larger than it don't have any fractional bits so don't need to
// be converted.
const fltSemantics &FltSem = DAG.EVTToAPFloatSemantics(ContainerVT);
unsigned Precision = APFloat::semanticsPrecision(FltSem);
APFloat MaxVal = APFloat(FltSem);
MaxVal.convertFromAPInt(APInt::getOneBitSet(Precision, Precision - 1),
/*IsSigned*/ false, APFloat::rmNearestTiesToEven);
SDValue MaxValNode =
DAG.getConstantFP(MaxVal, DL, ContainerVT.getVectorElementType());
SDValue MaxValSplat = DAG.getNode(RISCVISD::VFMV_V_F_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), MaxValNode, VL);
// If abs(Src) was larger than MaxVal or nan, keep it.
MVT SetccVT = MVT::getVectorVT(MVT::i1, ContainerVT.getVectorElementCount());
Mask =
DAG.getNode(RISCVISD::SETCC_VL, DL, SetccVT,
{Abs, MaxValSplat, DAG.getCondCode(ISD::SETOLT),
Mask, Mask, VL});
// Truncate to integer and convert back to FP.
MVT IntVT = ContainerVT.changeVectorElementTypeToInteger();
MVT XLenVT = Subtarget.getXLenVT();
SDValue Truncated;
switch (Op.getOpcode()) {
default:
llvm_unreachable("Unexpected opcode");
case ISD::FCEIL:
case ISD::VP_FCEIL:
case ISD::FFLOOR:
case ISD::VP_FFLOOR:
case ISD::FROUND:
case ISD::FROUNDEVEN:
case ISD::VP_FROUND:
case ISD::VP_FROUNDEVEN:
case ISD::VP_FROUNDTOZERO: {
RISCVFPRndMode::RoundingMode FRM = matchRoundingOp(Op.getOpcode());
assert(FRM != RISCVFPRndMode::Invalid);
Truncated = DAG.getNode(RISCVISD::VFCVT_RM_X_F_VL, DL, IntVT, Src, Mask,
DAG.getTargetConstant(FRM, DL, XLenVT), VL);
break;
}
case ISD::FTRUNC:
Truncated = DAG.getNode(RISCVISD::VFCVT_RTZ_X_F_VL, DL, IntVT, Src,
Mask, VL);
break;
case ISD::VP_FRINT:
Truncated = DAG.getNode(RISCVISD::VFCVT_X_F_VL, DL, IntVT, Src, Mask, VL);
break;
case ISD::VP_FNEARBYINT:
Truncated = DAG.getNode(RISCVISD::VFROUND_NOEXCEPT_VL, DL, ContainerVT, Src,
Mask, VL);
break;
}
// VFROUND_NOEXCEPT_VL includes SINT_TO_FP_VL.
if (Op.getOpcode() != ISD::VP_FNEARBYINT)
Truncated = DAG.getNode(RISCVISD::SINT_TO_FP_VL, DL, ContainerVT, Truncated,
Mask, VL);
// Restore the original sign so that -0.0 is preserved.
Truncated = DAG.getNode(RISCVISD::FCOPYSIGN_VL, DL, ContainerVT, Truncated,
Src, Src, Mask, VL);
if (!VT.isFixedLengthVector())
return Truncated;
return convertFromScalableVector(VT, Truncated, DAG, Subtarget);
}
static SDValue
lowerFTRUNC_FCEIL_FFLOOR_FROUND(SDValue Op, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
MVT VT = Op.getSimpleValueType();
if (VT.isVector())
return lowerVectorFTRUNC_FCEIL_FFLOOR_FROUND(Op, DAG, Subtarget);
if (DAG.shouldOptForSize())
return SDValue();
SDLoc DL(Op);
SDValue Src = Op.getOperand(0);
// Create an integer the size of the mantissa with the MSB set. This and all
// values larger than it don't have any fractional bits so don't need to be
// converted.
const fltSemantics &FltSem = DAG.EVTToAPFloatSemantics(VT);
unsigned Precision = APFloat::semanticsPrecision(FltSem);
APFloat MaxVal = APFloat(FltSem);
MaxVal.convertFromAPInt(APInt::getOneBitSet(Precision, Precision - 1),
/*IsSigned*/ false, APFloat::rmNearestTiesToEven);
SDValue MaxValNode = DAG.getConstantFP(MaxVal, DL, VT);
RISCVFPRndMode::RoundingMode FRM = matchRoundingOp(Op.getOpcode());
return DAG.getNode(RISCVISD::FROUND, DL, VT, Src, MaxValNode,
DAG.getTargetConstant(FRM, DL, Subtarget.getXLenVT()));
}
struct VIDSequence {
int64_t StepNumerator;
unsigned StepDenominator;
int64_t Addend;
};
static std::optional<uint64_t> getExactInteger(const APFloat &APF,
uint32_t BitWidth) {
APSInt ValInt(BitWidth, !APF.isNegative());
// We use an arbitrary rounding mode here. If a floating-point is an exact
// integer (e.g., 1.0), the rounding mode does not affect the output value. If
// the rounding mode changes the output value, then it is not an exact
// integer.
RoundingMode ArbitraryRM = RoundingMode::TowardZero;
bool IsExact;
// If it is out of signed integer range, it will return an invalid operation.
// If it is not an exact integer, IsExact is false.
if ((APF.convertToInteger(ValInt, ArbitraryRM, &IsExact) ==
APFloatBase::opInvalidOp) ||
!IsExact)
return std::nullopt;
return ValInt.extractBitsAsZExtValue(BitWidth, 0);
}
// Try to match an arithmetic-sequence BUILD_VECTOR [X,X+S,X+2*S,...,X+(N-1)*S]
// to the (non-zero) step S and start value X. This can be then lowered as the
// RVV sequence (VID * S) + X, for example.
// The step S is represented as an integer numerator divided by a positive
// denominator. Note that the implementation currently only identifies
// sequences in which either the numerator is +/- 1 or the denominator is 1. It
// cannot detect 2/3, for example.
// Note that this method will also match potentially unappealing index
// sequences, like <i32 0, i32 50939494>, however it is left to the caller to
// determine whether this is worth generating code for.
static std::optional<VIDSequence> isSimpleVIDSequence(SDValue Op) {
unsigned NumElts = Op.getNumOperands();
assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unexpected BUILD_VECTOR");
bool IsInteger = Op.getValueType().isInteger();
std::optional<unsigned> SeqStepDenom;
std::optional<int64_t> SeqStepNum, SeqAddend;
std::optional<std::pair<uint64_t, unsigned>> PrevElt;
unsigned EltSizeInBits = Op.getValueType().getScalarSizeInBits();
for (unsigned Idx = 0; Idx < NumElts; Idx++) {
// Assume undef elements match the sequence; we just have to be careful
// when interpolating across them.
if (Op.getOperand(Idx).isUndef())
continue;
uint64_t Val;
if (IsInteger) {
// The BUILD_VECTOR must be all constants.
if (!isa<ConstantSDNode>(Op.getOperand(Idx)))
return std::nullopt;
Val = Op.getConstantOperandVal(Idx) &
maskTrailingOnes<uint64_t>(EltSizeInBits);
} else {
// The BUILD_VECTOR must be all constants.
if (!isa<ConstantFPSDNode>(Op.getOperand(Idx)))
return std::nullopt;
if (auto ExactInteger = getExactInteger(
cast<ConstantFPSDNode>(Op.getOperand(Idx))->getValueAPF(),
EltSizeInBits))
Val = *ExactInteger;
else
return std::nullopt;
}
if (PrevElt) {
// Calculate the step since the last non-undef element, and ensure
// it's consistent across the entire sequence.
unsigned IdxDiff = Idx - PrevElt->second;
int64_t ValDiff = SignExtend64(Val - PrevElt->first, EltSizeInBits);
// A zero-value value difference means that we're somewhere in the middle
// of a fractional step, e.g. <0,0,0*,0,1,1,1,1>. Wait until we notice a
// step change before evaluating the sequence.
if (ValDiff == 0)
continue;
int64_t Remainder = ValDiff % IdxDiff;
// Normalize the step if it's greater than 1.
if (Remainder != ValDiff) {
// The difference must cleanly divide the element span.
if (Remainder != 0)
return std::nullopt;
ValDiff /= IdxDiff;
IdxDiff = 1;
}
if (!SeqStepNum)
SeqStepNum = ValDiff;
else if (ValDiff != SeqStepNum)
return std::nullopt;
if (!SeqStepDenom)
SeqStepDenom = IdxDiff;
else if (IdxDiff != *SeqStepDenom)
return std::nullopt;
}
// Record this non-undef element for later.
if (!PrevElt || PrevElt->first != Val)
PrevElt = std::make_pair(Val, Idx);
}
// We need to have logged a step for this to count as a legal index sequence.
if (!SeqStepNum || !SeqStepDenom)
return std::nullopt;
// Loop back through the sequence and validate elements we might have skipped
// while waiting for a valid step. While doing this, log any sequence addend.
for (unsigned Idx = 0; Idx < NumElts; Idx++) {
if (Op.getOperand(Idx).isUndef())
continue;
uint64_t Val;
if (IsInteger) {
Val = Op.getConstantOperandVal(Idx) &
maskTrailingOnes<uint64_t>(EltSizeInBits);
} else {
Val = *getExactInteger(
cast<ConstantFPSDNode>(Op.getOperand(Idx))->getValueAPF(),
EltSizeInBits);
}
uint64_t ExpectedVal =
(int64_t)(Idx * (uint64_t)*SeqStepNum) / *SeqStepDenom;
int64_t Addend = SignExtend64(Val - ExpectedVal, EltSizeInBits);
if (!SeqAddend)
SeqAddend = Addend;
else if (Addend != SeqAddend)
return std::nullopt;
}
assert(SeqAddend && "Must have an addend if we have a step");
return VIDSequence{*SeqStepNum, *SeqStepDenom, *SeqAddend};
}
// Match a splatted value (SPLAT_VECTOR/BUILD_VECTOR) of an EXTRACT_VECTOR_ELT
// and lower it as a VRGATHER_VX_VL from the source vector.
static SDValue matchSplatAsGather(SDValue SplatVal, MVT VT, const SDLoc &DL,
SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
if (SplatVal.getOpcode() != ISD::EXTRACT_VECTOR_ELT)
return SDValue();
SDValue Vec = SplatVal.getOperand(0);
// Only perform this optimization on vectors of the same size for simplicity.
// Don't perform this optimization for i1 vectors.
// FIXME: Support i1 vectors, maybe by promoting to i8?
if (Vec.getValueType() != VT || VT.getVectorElementType() == MVT::i1)
return SDValue();
SDValue Idx = SplatVal.getOperand(1);
// The index must be a legal type.
if (Idx.getValueType() != Subtarget.getXLenVT())
return SDValue();
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(DAG, VT, Subtarget);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
auto [Mask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
SDValue Gather = DAG.getNode(RISCVISD::VRGATHER_VX_VL, DL, ContainerVT, Vec,
Idx, DAG.getUNDEF(ContainerVT), Mask, VL);
if (!VT.isFixedLengthVector())
return Gather;
return convertFromScalableVector(VT, Gather, DAG, Subtarget);
}
static SDValue lowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
MVT VT = Op.getSimpleValueType();
assert(VT.isFixedLengthVector() && "Unexpected vector!");
MVT ContainerVT = getContainerForFixedLengthVector(DAG, VT, Subtarget);
SDLoc DL(Op);
auto [Mask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
MVT XLenVT = Subtarget.getXLenVT();
unsigned NumElts = Op.getNumOperands();
if (VT.getVectorElementType() == MVT::i1) {
if (ISD::isBuildVectorAllZeros(Op.getNode())) {
SDValue VMClr = DAG.getNode(RISCVISD::VMCLR_VL, DL, ContainerVT, VL);
return convertFromScalableVector(VT, VMClr, DAG, Subtarget);
}
if (ISD::isBuildVectorAllOnes(Op.getNode())) {
SDValue VMSet = DAG.getNode(RISCVISD::VMSET_VL, DL, ContainerVT, VL);
return convertFromScalableVector(VT, VMSet, DAG, Subtarget);
}
// Lower constant mask BUILD_VECTORs via an integer vector type, in
// scalar integer chunks whose bit-width depends on the number of mask
// bits and XLEN.
// First, determine the most appropriate scalar integer type to use. This
// is at most XLenVT, but may be shrunk to a smaller vector element type
// according to the size of the final vector - use i8 chunks rather than
// XLenVT if we're producing a v8i1. This results in more consistent
// codegen across RV32 and RV64.
unsigned NumViaIntegerBits = std::clamp(NumElts, 8u, Subtarget.getXLen());
NumViaIntegerBits = std::min(NumViaIntegerBits, Subtarget.getELEN());
if (ISD::isBuildVectorOfConstantSDNodes(Op.getNode())) {
// If we have to use more than one INSERT_VECTOR_ELT then this
// optimization is likely to increase code size; avoid peforming it in
// such a case. We can use a load from a constant pool in this case.
if (DAG.shouldOptForSize() && NumElts > NumViaIntegerBits)
return SDValue();
// Now we can create our integer vector type. Note that it may be larger
// than the resulting mask type: v4i1 would use v1i8 as its integer type.
MVT IntegerViaVecVT =
MVT::getVectorVT(MVT::getIntegerVT(NumViaIntegerBits),
divideCeil(NumElts, NumViaIntegerBits));
uint64_t Bits = 0;
unsigned BitPos = 0, IntegerEltIdx = 0;
SDValue Vec = DAG.getUNDEF(IntegerViaVecVT);
for (unsigned I = 0; I < NumElts; I++, BitPos++) {
// Once we accumulate enough bits to fill our scalar type, insert into
// our vector and clear our accumulated data.
if (I != 0 && I % NumViaIntegerBits == 0) {
if (NumViaIntegerBits <= 32)
Bits = SignExtend64<32>(Bits);
SDValue Elt = DAG.getConstant(Bits, DL, XLenVT);
Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, IntegerViaVecVT, Vec,
Elt, DAG.getConstant(IntegerEltIdx, DL, XLenVT));
Bits = 0;
BitPos = 0;
IntegerEltIdx++;
}
SDValue V = Op.getOperand(I);
bool BitValue = !V.isUndef() && cast<ConstantSDNode>(V)->getZExtValue();
Bits |= ((uint64_t)BitValue << BitPos);
}
// Insert the (remaining) scalar value into position in our integer
// vector type.
if (NumViaIntegerBits <= 32)
Bits = SignExtend64<32>(Bits);
SDValue Elt = DAG.getConstant(Bits, DL, XLenVT);
Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, IntegerViaVecVT, Vec, Elt,
DAG.getConstant(IntegerEltIdx, DL, XLenVT));
if (NumElts < NumViaIntegerBits) {
// If we're producing a smaller vector than our minimum legal integer
// type, bitcast to the equivalent (known-legal) mask type, and extract
// our final mask.
assert(IntegerViaVecVT == MVT::v1i8 && "Unexpected mask vector type");
Vec = DAG.getBitcast(MVT::v8i1, Vec);
Vec = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, Vec,
DAG.getConstant(0, DL, XLenVT));
} else {
// Else we must have produced an integer type with the same size as the
// mask type; bitcast for the final result.
assert(VT.getSizeInBits() == IntegerViaVecVT.getSizeInBits());
Vec = DAG.getBitcast(VT, Vec);
}
return Vec;
}
// A BUILD_VECTOR can be lowered as a SETCC. For each fixed-length mask
// vector type, we have a legal equivalently-sized i8 type, so we can use
// that.
MVT WideVecVT = VT.changeVectorElementType(MVT::i8);
SDValue VecZero = DAG.getConstant(0, DL, WideVecVT);
SDValue WideVec;
if (SDValue Splat = cast<BuildVectorSDNode>(Op)->getSplatValue()) {
// For a splat, perform a scalar truncate before creating the wider
// vector.
assert(Splat.getValueType() == XLenVT &&
"Unexpected type for i1 splat value");
Splat = DAG.getNode(ISD::AND, DL, XLenVT, Splat,
DAG.getConstant(1, DL, XLenVT));
WideVec = DAG.getSplatBuildVector(WideVecVT, DL, Splat);
} else {
SmallVector<SDValue, 8> Ops(Op->op_values());
WideVec = DAG.getBuildVector(WideVecVT, DL, Ops);
SDValue VecOne = DAG.getConstant(1, DL, WideVecVT);
WideVec = DAG.getNode(ISD::AND, DL, WideVecVT, WideVec, VecOne);
}
return DAG.getSetCC(DL, VT, WideVec, VecZero, ISD::SETNE);
}
if (SDValue Splat = cast<BuildVectorSDNode>(Op)->getSplatValue()) {
if (auto Gather = matchSplatAsGather(Splat, VT, DL, DAG, Subtarget))
return Gather;
unsigned Opc = VT.isFloatingPoint() ? RISCVISD::VFMV_V_F_VL
: RISCVISD::VMV_V_X_VL;
Splat =
DAG.getNode(Opc, DL, ContainerVT, DAG.getUNDEF(ContainerVT), Splat, VL);
return convertFromScalableVector(VT, Splat, DAG, Subtarget);
}
// Try and match index sequences, which we can lower to the vid instruction
// with optional modifications. An all-undef vector is matched by
// getSplatValue, above.
if (auto SimpleVID = isSimpleVIDSequence(Op)) {
int64_t StepNumerator = SimpleVID->StepNumerator;
unsigned StepDenominator = SimpleVID->StepDenominator;
int64_t Addend = SimpleVID->Addend;
assert(StepNumerator != 0 && "Invalid step");
bool Negate = false;
int64_t SplatStepVal = StepNumerator;
unsigned StepOpcode = ISD::MUL;
if (StepNumerator != 1) {
if (isPowerOf2_64(std::abs(StepNumerator))) {
Negate = StepNumerator < 0;
StepOpcode = ISD::SHL;
SplatStepVal = Log2_64(std::abs(StepNumerator));
}
}
// Only emit VIDs with suitably-small steps/addends. We use imm5 is a
// threshold since it's the immediate value many RVV instructions accept.
// There is no vmul.vi instruction so ensure multiply constant can fit in
// a single addi instruction.
if (((StepOpcode == ISD::MUL && isInt<12>(SplatStepVal)) ||
(StepOpcode == ISD::SHL && isUInt<5>(SplatStepVal))) &&
isPowerOf2_32(StepDenominator) &&
(SplatStepVal >= 0 || StepDenominator == 1) && isInt<5>(Addend)) {
MVT VIDVT =
VT.isFloatingPoint() ? VT.changeVectorElementTypeToInteger() : VT;
MVT VIDContainerVT =
getContainerForFixedLengthVector(DAG, VIDVT, Subtarget);
SDValue VID = DAG.getNode(RISCVISD::VID_VL, DL, VIDContainerVT, Mask, VL);
// Convert right out of the scalable type so we can use standard ISD
// nodes for the rest of the computation. If we used scalable types with
// these, we'd lose the fixed-length vector info and generate worse
// vsetvli code.
VID = convertFromScalableVector(VIDVT, VID, DAG, Subtarget);
if ((StepOpcode == ISD::MUL && SplatStepVal != 1) ||
(StepOpcode == ISD::SHL && SplatStepVal != 0)) {
SDValue SplatStep = DAG.getSplatBuildVector(
VIDVT, DL, DAG.getConstant(SplatStepVal, DL, XLenVT));
VID = DAG.getNode(StepOpcode, DL, VIDVT, VID, SplatStep);
}
if (StepDenominator != 1) {
SDValue SplatStep = DAG.getSplatBuildVector(
VIDVT, DL, DAG.getConstant(Log2_64(StepDenominator), DL, XLenVT));
VID = DAG.getNode(ISD::SRL, DL, VIDVT, VID, SplatStep);
}
if (Addend != 0 || Negate) {
SDValue SplatAddend = DAG.getSplatBuildVector(
VIDVT, DL, DAG.getConstant(Addend, DL, XLenVT));
VID = DAG.getNode(Negate ? ISD::SUB : ISD::ADD, DL, VIDVT, SplatAddend,
VID);
}
if (VT.isFloatingPoint()) {
// TODO: Use vfwcvt to reduce register pressure.
VID = DAG.getNode(ISD::SINT_TO_FP, DL, VT, VID);
}
return VID;
}
}
// Attempt to detect "hidden" splats, which only reveal themselves as splats
// when re-interpreted as a vector with a larger element type. For example,
// v4i16 = build_vector i16 0, i16 1, i16 0, i16 1
// could be instead splat as
// v2i32 = build_vector i32 0x00010000, i32 0x00010000
// TODO: This optimization could also work on non-constant splats, but it
// would require bit-manipulation instructions to construct the splat value.
SmallVector<SDValue> Sequence;
unsigned EltBitSize = VT.getScalarSizeInBits();
const auto *BV = cast<BuildVectorSDNode>(Op);
if (VT.isInteger() && EltBitSize < 64 &&
ISD::isBuildVectorOfConstantSDNodes(Op.getNode()) &&
BV->getRepeatedSequence(Sequence) &&
(Sequence.size() * EltBitSize) <= 64) {
unsigned SeqLen = Sequence.size();
MVT ViaIntVT = MVT::getIntegerVT(EltBitSize * SeqLen);
MVT ViaVecVT = MVT::getVectorVT(ViaIntVT, NumElts / SeqLen);
assert((ViaIntVT == MVT::i16 || ViaIntVT == MVT::i32 ||
ViaIntVT == MVT::i64) &&
"Unexpected sequence type");
unsigned EltIdx = 0;
uint64_t EltMask = maskTrailingOnes<uint64_t>(EltBitSize);
uint64_t SplatValue = 0;
// Construct the amalgamated value which can be splatted as this larger
// vector type.
for (const auto &SeqV : Sequence) {
if (!SeqV.isUndef())
SplatValue |= ((cast<ConstantSDNode>(SeqV)->getZExtValue() & EltMask)
<< (EltIdx * EltBitSize));
EltIdx++;
}
// On RV64, sign-extend from 32 to 64 bits where possible in order to
// achieve better constant materializion.
if (Subtarget.is64Bit() && ViaIntVT == MVT::i32)
SplatValue = SignExtend64<32>(SplatValue);
// Since we can't introduce illegal i64 types at this stage, we can only
// perform an i64 splat on RV32 if it is its own sign-extended value. That
// way we can use RVV instructions to splat.
assert((ViaIntVT.bitsLE(XLenVT) ||
(!Subtarget.is64Bit() && ViaIntVT == MVT::i64)) &&
"Unexpected bitcast sequence");
if (ViaIntVT.bitsLE(XLenVT) || isInt<32>(SplatValue)) {
SDValue ViaVL =
DAG.getConstant(ViaVecVT.getVectorNumElements(), DL, XLenVT);
MVT ViaContainerVT =
getContainerForFixedLengthVector(DAG, ViaVecVT, Subtarget);
SDValue Splat =
DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ViaContainerVT,
DAG.getUNDEF(ViaContainerVT),
DAG.getConstant(SplatValue, DL, XLenVT), ViaVL);
Splat = convertFromScalableVector(ViaVecVT, Splat, DAG, Subtarget);
return DAG.getBitcast(VT, Splat);
}
}
// Try and optimize BUILD_VECTORs with "dominant values" - these are values
// which constitute a large proportion of the elements. In such cases we can
// splat a vector with the dominant element and make up the shortfall with
// INSERT_VECTOR_ELTs.
// Note that this includes vectors of 2 elements by association. The
// upper-most element is the "dominant" one, allowing us to use a splat to
// "insert" the upper element, and an insert of the lower element at position
// 0, which improves codegen.
SDValue DominantValue;
unsigned MostCommonCount = 0;
DenseMap<SDValue, unsigned> ValueCounts;
unsigned NumUndefElts =
count_if(Op->op_values(), [](const SDValue &V) { return V.isUndef(); });
// Track the number of scalar loads we know we'd be inserting, estimated as
// any non-zero floating-point constant. Other kinds of element are either
// already in registers or are materialized on demand. The threshold at which
// a vector load is more desirable than several scalar materializion and
// vector-insertion instructions is not known.
unsigned NumScalarLoads = 0;
for (SDValue V : Op->op_values()) {
if (V.isUndef())
continue;
ValueCounts.insert(std::make_pair(V, 0));
unsigned &Count = ValueCounts[V];
if (auto *CFP = dyn_cast<ConstantFPSDNode>(V))
NumScalarLoads += !CFP->isExactlyValue(+0.0);
// Is this value dominant? In case of a tie, prefer the highest element as
// it's cheaper to insert near the beginning of a vector than it is at the
// end.
if (++Count >= MostCommonCount) {
DominantValue = V;
MostCommonCount = Count;
}
}
assert(DominantValue && "Not expecting an all-undef BUILD_VECTOR");
unsigned NumDefElts = NumElts - NumUndefElts;
unsigned DominantValueCountThreshold = NumDefElts <= 2 ? 0 : NumDefElts - 2;
// Don't perform this optimization when optimizing for size, since
// materializing elements and inserting them tends to cause code bloat.
if (!DAG.shouldOptForSize() && NumScalarLoads < NumElts &&
((MostCommonCount > DominantValueCountThreshold) ||
(ValueCounts.size() <= Log2_32(NumDefElts)))) {
// Start by splatting the most common element.
SDValue Vec = DAG.getSplatBuildVector(VT, DL, DominantValue);
DenseSet<SDValue> Processed{DominantValue};
MVT SelMaskTy = VT.changeVectorElementType(MVT::i1);
for (const auto &OpIdx : enumerate(Op->ops())) {
const SDValue &V = OpIdx.value();
if (V.isUndef() || !Processed.insert(V).second)
continue;
if (ValueCounts[V] == 1) {
Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VT, Vec, V,
DAG.getConstant(OpIdx.index(), DL, XLenVT));
} else {
// Blend in all instances of this value using a VSELECT, using a
// mask where each bit signals whether that element is the one
// we're after.
SmallVector<SDValue> Ops;
transform(Op->op_values(), std::back_inserter(Ops), [&](SDValue V1) {
return DAG.getConstant(V == V1, DL, XLenVT);
});
Vec = DAG.getNode(ISD::VSELECT, DL, VT,
DAG.getBuildVector(SelMaskTy, DL, Ops),
DAG.getSplatBuildVector(VT, DL, V), Vec);
}
}
return Vec;
}
return SDValue();
}
static SDValue splatPartsI64WithVL(const SDLoc &DL, MVT VT, SDValue Passthru,
SDValue Lo, SDValue Hi, SDValue VL,
SelectionDAG &DAG) {
if (!Passthru)
Passthru = DAG.getUNDEF(VT);
if (isa<ConstantSDNode>(Lo) && isa<ConstantSDNode>(Hi)) {
int32_t LoC = cast<ConstantSDNode>(Lo)->getSExtValue();
int32_t HiC = cast<ConstantSDNode>(Hi)->getSExtValue();
// If Hi constant is all the same sign bit as Lo, lower this as a custom
// node in order to try and match RVV vector/scalar instructions.
if ((LoC >> 31) == HiC)
return DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VT, Passthru, Lo, VL);
// If vl is equal to XLEN_MAX and Hi constant is equal to Lo, we could use
// vmv.v.x whose EEW = 32 to lower it.
if (LoC == HiC && isAllOnesConstant(VL)) {
MVT InterVT = MVT::getVectorVT(MVT::i32, VT.getVectorElementCount() * 2);
// TODO: if vl <= min(VLMAX), we can also do this. But we could not
// access the subtarget here now.
auto InterVec = DAG.getNode(
RISCVISD::VMV_V_X_VL, DL, InterVT, DAG.getUNDEF(InterVT), Lo,
DAG.getRegister(RISCV::X0, MVT::i32));
return DAG.getNode(ISD::BITCAST, DL, VT, InterVec);
}
}
// Fall back to a stack store and stride x0 vector load.
return DAG.getNode(RISCVISD::SPLAT_VECTOR_SPLIT_I64_VL, DL, VT, Passthru, Lo,
Hi, VL);
}
// Called by type legalization to handle splat of i64 on RV32.
// FIXME: We can optimize this when the type has sign or zero bits in one
// of the halves.
static SDValue splatSplitI64WithVL(const SDLoc &DL, MVT VT, SDValue Passthru,
SDValue Scalar, SDValue VL,
SelectionDAG &DAG) {
assert(Scalar.getValueType() == MVT::i64 && "Unexpected VT!");
SDValue Lo, Hi;
std::tie(Lo, Hi) = DAG.SplitScalar(Scalar, DL, MVT::i32, MVT::i32);
return splatPartsI64WithVL(DL, VT, Passthru, Lo, Hi, VL, DAG);
}
// This function lowers a splat of a scalar operand Splat with the vector
// length VL. It ensures the final sequence is type legal, which is useful when
// lowering a splat after type legalization.
static SDValue lowerScalarSplat(SDValue Passthru, SDValue Scalar, SDValue VL,
MVT VT, SDLoc DL, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
bool HasPassthru = Passthru && !Passthru.isUndef();
if (!HasPassthru && !Passthru)
Passthru = DAG.getUNDEF(VT);
if (VT.isFloatingPoint()) {
// If VL is 1, we could use vfmv.s.f.
if (isOneConstant(VL))
return DAG.getNode(RISCVISD::VFMV_S_F_VL, DL, VT, Passthru, Scalar, VL);
return DAG.getNode(RISCVISD::VFMV_V_F_VL, DL, VT, Passthru, Scalar, VL);
}
MVT XLenVT = Subtarget.getXLenVT();
// Simplest case is that the operand needs to be promoted to XLenVT.
if (Scalar.getValueType().bitsLE(XLenVT)) {
// If the operand is a constant, sign extend to increase our chances
// of being able to use a .vi instruction. ANY_EXTEND would become a
// a zero extend and the simm5 check in isel would fail.
// FIXME: Should we ignore the upper bits in isel instead?
unsigned ExtOpc =
isa<ConstantSDNode>(Scalar) ? ISD::SIGN_EXTEND : ISD::ANY_EXTEND;
Scalar = DAG.getNode(ExtOpc, DL, XLenVT, Scalar);
ConstantSDNode *Const = dyn_cast<ConstantSDNode>(Scalar);
// If VL is 1 and the scalar value won't benefit from immediate, we could
// use vmv.s.x.
if (isOneConstant(VL) &&
(!Const || isNullConstant(Scalar) || !isInt<5>(Const->getSExtValue())))
return DAG.getNode(RISCVISD::VMV_S_X_VL, DL, VT, Passthru, Scalar, VL);
return DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VT, Passthru, Scalar, VL);
}
assert(XLenVT == MVT::i32 && Scalar.getValueType() == MVT::i64 &&
"Unexpected scalar for splat lowering!");
if (isOneConstant(VL) && isNullConstant(Scalar))
return DAG.getNode(RISCVISD::VMV_S_X_VL, DL, VT, Passthru,
DAG.getConstant(0, DL, XLenVT), VL);
// Otherwise use the more complicated splatting algorithm.
return splatSplitI64WithVL(DL, VT, Passthru, Scalar, VL, DAG);
}
static MVT getLMUL1VT(MVT VT) {
assert(VT.getVectorElementType().getSizeInBits() <= 64 &&
"Unexpected vector MVT");
return MVT::getScalableVectorVT(
VT.getVectorElementType(),
RISCV::RVVBitsPerBlock / VT.getVectorElementType().getSizeInBits());
}
// This function lowers an insert of a scalar operand Scalar into lane
// 0 of the vector regardless of the value of VL. The contents of the
// remaining lanes of the result vector are unspecified. VL is assumed
// to be non-zero.
static SDValue lowerScalarInsert(SDValue Scalar, SDValue VL,
MVT VT, SDLoc DL, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
const MVT XLenVT = Subtarget.getXLenVT();
SDValue Passthru = DAG.getUNDEF(VT);
if (VT.isFloatingPoint()) {
// TODO: Use vmv.v.i for appropriate constants
// Use M1 or smaller to avoid over constraining register allocation
const MVT M1VT = getLMUL1VT(VT);
auto InnerVT = VT.bitsLE(M1VT) ? VT : M1VT;
SDValue Result = DAG.getNode(RISCVISD::VFMV_S_F_VL, DL, InnerVT,
DAG.getUNDEF(InnerVT), Scalar, VL);
if (VT != InnerVT)
Result = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT,
DAG.getUNDEF(VT),
Result, DAG.getConstant(0, DL, XLenVT));
return Result;
}
// Avoid the tricky legalization cases by falling back to using the
// splat code which already handles it gracefully.
if (!Scalar.getValueType().bitsLE(XLenVT))
return lowerScalarSplat(DAG.getUNDEF(VT), Scalar,
DAG.getConstant(1, DL, XLenVT),
VT, DL, DAG, Subtarget);
// If the operand is a constant, sign extend to increase our chances
// of being able to use a .vi instruction. ANY_EXTEND would become a
// a zero extend and the simm5 check in isel would fail.
// FIXME: Should we ignore the upper bits in isel instead?
unsigned ExtOpc =
isa<ConstantSDNode>(Scalar) ? ISD::SIGN_EXTEND : ISD::ANY_EXTEND;
Scalar = DAG.getNode(ExtOpc, DL, XLenVT, Scalar);
// We use a vmv.v.i if possible. We limit this to LMUL1. LMUL2 or
// higher would involve overly constraining the register allocator for
// no purpose.
if (ConstantSDNode *Const = dyn_cast<ConstantSDNode>(Scalar)) {
if (!isNullConstant(Scalar) && isInt<5>(Const->getSExtValue()) &&
VT.bitsLE(getLMUL1VT(VT)))
return DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VT, Passthru, Scalar, VL);
}
// Use M1 or smaller to avoid over constraining register allocation
const MVT M1VT = getLMUL1VT(VT);
auto InnerVT = VT.bitsLE(M1VT) ? VT : M1VT;
SDValue Result = DAG.getNode(RISCVISD::VMV_S_X_VL, DL, InnerVT,
DAG.getUNDEF(InnerVT), Scalar, VL);
if (VT != InnerVT)
Result = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT,
DAG.getUNDEF(VT),
Result, DAG.getConstant(0, DL, XLenVT));
return Result;
}
// Is this a shuffle extracts either the even or odd elements of a vector?
// That is, specifically, either (a) or (b) below.
// t34: v8i8 = extract_subvector t11, Constant:i64<0>
// t33: v8i8 = extract_subvector t11, Constant:i64<8>
// a) t35: v8i8 = vector_shuffle<0,2,4,6,8,10,12,14> t34, t33
// b) t35: v8i8 = vector_shuffle<1,3,5,7,9,11,13,15> t34, t33
// Returns {Src Vector, Even Elements} om success
static bool isDeinterleaveShuffle(MVT VT, MVT ContainerVT, SDValue V1,
SDValue V2, ArrayRef<int> Mask,
const RISCVSubtarget &Subtarget) {
// Need to be able to widen the vector.
if (VT.getScalarSizeInBits() >= Subtarget.getELEN())
return false;
// Both input must be extracts.
if (V1.getOpcode() != ISD::EXTRACT_SUBVECTOR ||
V2.getOpcode() != ISD::EXTRACT_SUBVECTOR)
return false;
// Extracting from the same source.
SDValue Src = V1.getOperand(0);
if (Src != V2.getOperand(0))
return false;
// Src needs to have twice the number of elements.
if (Src.getValueType().getVectorNumElements() != (Mask.size() * 2))
return false;
// The extracts must extract the two halves of the source.
if (V1.getConstantOperandVal(1) != 0 ||
V2.getConstantOperandVal(1) != Mask.size())
return false;
// First index must be the first even or odd element from V1.
if (Mask[0] != 0 && Mask[0] != 1)
return false;
// The others must increase by 2 each time.
// TODO: Support undef elements?
for (unsigned i = 1; i != Mask.size(); ++i)
if (Mask[i] != Mask[i - 1] + 2)
return false;
return true;
}
/// Is this shuffle interleaving contiguous elements from one vector into the
/// even elements and contiguous elements from another vector into the odd
/// elements. \p Src1 will contain the element that should be in the first even
/// element. \p Src2 will contain the element that should be in the first odd
/// element. These can be the first element in a source or the element half
/// way through the source.
static bool isInterleaveShuffle(ArrayRef<int> Mask, MVT VT, int &EvenSrc,
int &OddSrc, const RISCVSubtarget &Subtarget) {
// We need to be able to widen elements to the next larger integer type.
if (VT.getScalarSizeInBits() >= Subtarget.getELEN())
return false;
int Size = Mask.size();
assert(Size == (int)VT.getVectorNumElements() && "Unexpected mask size");
SmallVector<unsigned, 2> StartIndexes;
if (!ShuffleVectorInst::isInterleaveMask(Mask, 2, Size * 2, StartIndexes))
return false;
EvenSrc = StartIndexes[0];
OddSrc = StartIndexes[1];
// One source should be low half of first vector.
if (EvenSrc != 0 && OddSrc != 0)
return false;
return true;
}
/// Match shuffles that concatenate two vectors, rotate the concatenation,
/// and then extract the original number of elements from the rotated result.
/// This is equivalent to vector.splice or X86's PALIGNR instruction. The
/// returned rotation amount is for a rotate right, where elements move from
/// higher elements to lower elements. \p LoSrc indicates the first source
/// vector of the rotate or -1 for undef. \p HiSrc indicates the second vector
/// of the rotate or -1 for undef. At least one of \p LoSrc and \p HiSrc will be
/// 0 or 1 if a rotation is found.
///
/// NOTE: We talk about rotate to the right which matches how bit shift and
/// rotate instructions are described where LSBs are on the right, but LLVM IR
/// and the table below write vectors with the lowest elements on the left.
static int isElementRotate(int &LoSrc, int &HiSrc, ArrayRef<int> Mask) {
int Size = Mask.size();
// We need to detect various ways of spelling a rotation:
// [11, 12, 13, 14, 15, 0, 1, 2]
// [-1, 12, 13, 14, -1, -1, 1, -1]
// [-1, -1, -1, -1, -1, -1, 1, 2]
// [ 3, 4, 5, 6, 7, 8, 9, 10]
// [-1, 4, 5, 6, -1, -1, 9, -1]
// [-1, 4, 5, 6, -1, -1, -1, -1]
int Rotation = 0;
LoSrc = -1;
HiSrc = -1;
for (int i = 0; i != Size; ++i) {
int M = Mask[i];
if (M < 0)
continue;
// Determine where a rotate vector would have started.
int StartIdx = i - (M % Size);
// The identity rotation isn't interesting, stop.
if (StartIdx == 0)
return -1;
// If we found the tail of a vector the rotation must be the missing
// front. If we found the head of a vector, it must be how much of the
// head.
int CandidateRotation = StartIdx < 0 ? -StartIdx : Size - StartIdx;
if (Rotation == 0)
Rotation = CandidateRotation;
else if (Rotation != CandidateRotation)
// The rotations don't match, so we can't match this mask.
return -1;
// Compute which value this mask is pointing at.
int MaskSrc = M < Size ? 0 : 1;
// Compute which of the two target values this index should be assigned to.
// This reflects whether the high elements are remaining or the low elemnts
// are remaining.
int &TargetSrc = StartIdx < 0 ? HiSrc : LoSrc;
// Either set up this value if we've not encountered it before, or check
// that it remains consistent.
if (TargetSrc < 0)
TargetSrc = MaskSrc;
else if (TargetSrc != MaskSrc)
// This may be a rotation, but it pulls from the inputs in some
// unsupported interleaving.
return -1;
}
// Check that we successfully analyzed the mask, and normalize the results.
assert(Rotation != 0 && "Failed to locate a viable rotation!");
assert((LoSrc >= 0 || HiSrc >= 0) &&
"Failed to find a rotated input vector!");
return Rotation;
}
// Lower a deinterleave shuffle to vnsrl.
// [a, p, b, q, c, r, d, s] -> [a, b, c, d] (EvenElts == true)
// -> [p, q, r, s] (EvenElts == false)
// VT is the type of the vector to return, <[vscale x ]n x ty>
// Src is the vector to deinterleave of type <[vscale x ]n*2 x ty>
static SDValue getDeinterleaveViaVNSRL(const SDLoc &DL, MVT VT, SDValue Src,
bool EvenElts,
const RISCVSubtarget &Subtarget,
SelectionDAG &DAG) {
// The result is a vector of type <m x n x ty>
MVT ContainerVT = VT;
// Convert fixed vectors to scalable if needed
if (ContainerVT.isFixedLengthVector()) {
assert(Src.getSimpleValueType().isFixedLengthVector());
ContainerVT = getContainerForFixedLengthVector(DAG, ContainerVT, Subtarget);
// The source is a vector of type <m x n*2 x ty>
MVT SrcContainerVT =
MVT::getVectorVT(ContainerVT.getVectorElementType(),
ContainerVT.getVectorElementCount() * 2);
Src = convertToScalableVector(SrcContainerVT, Src, DAG, Subtarget);
}
auto [TrueMask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
// Bitcast the source vector from <m x n*2 x ty> -> <m x n x ty*2>
// This also converts FP to int.
unsigned EltBits = ContainerVT.getScalarSizeInBits();
MVT WideSrcContainerVT = MVT::getVectorVT(
MVT::getIntegerVT(EltBits * 2), ContainerVT.getVectorElementCount());
Src = DAG.getBitcast(WideSrcContainerVT, Src);
// The integer version of the container type.
MVT IntContainerVT = ContainerVT.changeVectorElementTypeToInteger();
// If we want even elements, then the shift amount is 0. Otherwise, shift by
// the original element size.
unsigned Shift = EvenElts ? 0 : EltBits;
SDValue SplatShift = DAG.getNode(
RISCVISD::VMV_V_X_VL, DL, IntContainerVT, DAG.getUNDEF(ContainerVT),
DAG.getConstant(Shift, DL, Subtarget.getXLenVT()), VL);
SDValue Res =
DAG.getNode(RISCVISD::VNSRL_VL, DL, IntContainerVT, Src, SplatShift,
DAG.getUNDEF(IntContainerVT), TrueMask, VL);
// Cast back to FP if needed.
Res = DAG.getBitcast(ContainerVT, Res);
if (VT.isFixedLengthVector())
Res = convertFromScalableVector(VT, Res, DAG, Subtarget);
return Res;
}
static SDValue
getVSlidedown(SelectionDAG &DAG, const RISCVSubtarget &Subtarget, SDLoc DL,
EVT VT, SDValue Merge, SDValue Op, SDValue Offset, SDValue Mask,
SDValue VL,
unsigned Policy = RISCVII::TAIL_UNDISTURBED_MASK_UNDISTURBED) {
if (Merge.isUndef())
Policy = RISCVII::TAIL_AGNOSTIC | RISCVII::MASK_AGNOSTIC;
SDValue PolicyOp = DAG.getTargetConstant(Policy, DL, Subtarget.getXLenVT());
SDValue Ops[] = {Merge, Op, Offset, Mask, VL, PolicyOp};
return DAG.getNode(RISCVISD::VSLIDEDOWN_VL, DL, VT, Ops);
}
static SDValue
getVSlideup(SelectionDAG &DAG, const RISCVSubtarget &Subtarget, SDLoc DL,
EVT VT, SDValue Merge, SDValue Op, SDValue Offset, SDValue Mask,
SDValue VL,
unsigned Policy = RISCVII::TAIL_UNDISTURBED_MASK_UNDISTURBED) {
if (Merge.isUndef())
Policy = RISCVII::TAIL_AGNOSTIC | RISCVII::MASK_AGNOSTIC;
SDValue PolicyOp = DAG.getTargetConstant(Policy, DL, Subtarget.getXLenVT());
SDValue Ops[] = {Merge, Op, Offset, Mask, VL, PolicyOp};
return DAG.getNode(RISCVISD::VSLIDEUP_VL, DL, VT, Ops);
}
// Lower the following shuffle to vslidedown.
// a)
// t49: v8i8 = extract_subvector t13, Constant:i64<0>
// t109: v8i8 = extract_subvector t13, Constant:i64<8>
// t108: v8i8 = vector_shuffle<1,2,3,4,5,6,7,8> t49, t106
// b)
// t69: v16i16 = extract_subvector t68, Constant:i64<0>
// t23: v8i16 = extract_subvector t69, Constant:i64<0>
// t29: v4i16 = extract_subvector t23, Constant:i64<4>
// t26: v8i16 = extract_subvector t69, Constant:i64<8>
// t30: v4i16 = extract_subvector t26, Constant:i64<0>
// t54: v4i16 = vector_shuffle<1,2,3,4> t29, t30
static SDValue lowerVECTOR_SHUFFLEAsVSlidedown(const SDLoc &DL, MVT VT,
SDValue V1, SDValue V2,
ArrayRef<int> Mask,
const RISCVSubtarget &Subtarget,
SelectionDAG &DAG) {
auto findNonEXTRACT_SUBVECTORParent =
[](SDValue Parent) -> std::pair<SDValue, uint64_t> {
uint64_t Offset = 0;
while (Parent.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
// EXTRACT_SUBVECTOR can be used to extract a fixed-width vector from
// a scalable vector. But we don't want to match the case.
Parent.getOperand(0).getSimpleValueType().isFixedLengthVector()) {
Offset += Parent.getConstantOperandVal(1);
Parent = Parent.getOperand(0);
}
return std::make_pair(Parent, Offset);
};
auto [V1Src, V1IndexOffset] = findNonEXTRACT_SUBVECTORParent(V1);
auto [V2Src, V2IndexOffset] = findNonEXTRACT_SUBVECTORParent(V2);
// Extracting from the same source.
SDValue Src = V1Src;
if (Src != V2Src)
return SDValue();
// Rebuild mask because Src may be from multiple EXTRACT_SUBVECTORs.
SmallVector<int, 16> NewMask(Mask);
for (size_t i = 0; i != NewMask.size(); ++i) {
if (NewMask[i] == -1)
continue;
if (static_cast<size_t>(NewMask[i]) < NewMask.size()) {
NewMask[i] = NewMask[i] + V1IndexOffset;
} else {
// Minus NewMask.size() is needed. Otherwise, the b case would be
// <5,6,7,12> instead of <5,6,7,8>.
NewMask[i] = NewMask[i] - NewMask.size() + V2IndexOffset;
}
}
// First index must be known and non-zero. It will be used as the slidedown
// amount.
if (NewMask[0] <= 0)
return SDValue();
// NewMask is also continuous.
for (unsigned i = 1; i != NewMask.size(); ++i)
if (NewMask[i - 1] + 1 != NewMask[i])
return SDValue();
MVT XLenVT = Subtarget.getXLenVT();
MVT SrcVT = Src.getSimpleValueType();
MVT ContainerVT = getContainerForFixedLengthVector(DAG, SrcVT, Subtarget);
auto [TrueMask, VL] = getDefaultVLOps(SrcVT, ContainerVT, DL, DAG, Subtarget);
SDValue Slidedown =
getVSlidedown(DAG, Subtarget, DL, ContainerVT, DAG.getUNDEF(ContainerVT),
convertToScalableVector(ContainerVT, Src, DAG, Subtarget),
DAG.getConstant(NewMask[0], DL, XLenVT), TrueMask, VL);
return DAG.getNode(
ISD::EXTRACT_SUBVECTOR, DL, VT,
convertFromScalableVector(SrcVT, Slidedown, DAG, Subtarget),
DAG.getConstant(0, DL, XLenVT));
}
// Because vslideup leaves the destination elements at the start intact, we can
// use it to perform shuffles that insert subvectors:
//
// vector_shuffle v8:v8i8, v9:v8i8, <0, 1, 2, 3, 8, 9, 10, 11>
// ->
// vsetvli zero, 8, e8, mf2, ta, ma
// vslideup.vi v8, v9, 4
//
// vector_shuffle v8:v8i8, v9:v8i8 <0, 1, 8, 9, 10, 5, 6, 7>
// ->
// vsetvli zero, 5, e8, mf2, tu, ma
// vslideup.v1 v8, v9, 2
static SDValue lowerVECTOR_SHUFFLEAsVSlideup(const SDLoc &DL, MVT VT,
SDValue V1, SDValue V2,
ArrayRef<int> Mask,
const RISCVSubtarget &Subtarget,
SelectionDAG &DAG) {
unsigned NumElts = VT.getVectorNumElements();
int NumSubElts, Index;
if (!ShuffleVectorInst::isInsertSubvectorMask(Mask, NumElts, NumSubElts,
Index))
return SDValue();
bool OpsSwapped = Mask[Index] < (int)NumElts;
SDValue InPlace = OpsSwapped ? V2 : V1;
SDValue ToInsert = OpsSwapped ? V1 : V2;
MVT XLenVT = Subtarget.getXLenVT();
MVT ContainerVT = getContainerForFixedLengthVector(DAG, VT, Subtarget);
auto TrueMask = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).first;
// We slide up by the index that the subvector is being inserted at, and set
// VL to the index + the number of elements being inserted.
unsigned Policy = RISCVII::TAIL_UNDISTURBED_MASK_UNDISTURBED | RISCVII::MASK_AGNOSTIC;
// If the we're adding a suffix to the in place vector, i.e. inserting right
// up to the very end of it, then we don't actually care about the tail.
if (NumSubElts + Index >= (int)NumElts)
Policy |= RISCVII::TAIL_AGNOSTIC;
SDValue Slideup = getVSlideup(
DAG, Subtarget, DL, ContainerVT,
convertToScalableVector(ContainerVT, InPlace, DAG, Subtarget),
convertToScalableVector(ContainerVT, ToInsert, DAG, Subtarget),
DAG.getConstant(Index, DL, XLenVT), TrueMask,
DAG.getConstant(NumSubElts + Index, DL, XLenVT),
Policy);
return convertFromScalableVector(VT, Slideup, DAG, Subtarget);
}
// Given two input vectors of <[vscale x ]n x ty>, use vwaddu.vv and vwmaccu.vx
// to create an interleaved vector of <[vscale x] n*2 x ty>.
// This requires that the size of ty is less than the subtarget's maximum ELEN.
static SDValue getWideningInterleave(SDValue EvenV, SDValue OddV, SDLoc &DL,
SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
MVT VecVT = EvenV.getSimpleValueType();
MVT VecContainerVT = VecVT; // <vscale x n x ty>
// Convert fixed vectors to scalable if needed
if (VecContainerVT.isFixedLengthVector()) {
VecContainerVT = getContainerForFixedLengthVector(DAG, VecVT, Subtarget);
EvenV = convertToScalableVector(VecContainerVT, EvenV, DAG, Subtarget);
OddV = convertToScalableVector(VecContainerVT, OddV, DAG, Subtarget);
}
assert(VecVT.getScalarSizeInBits() < Subtarget.getELEN());
// We're working with a vector of the same size as the resulting
// interleaved vector, but with half the number of elements and
// twice the SEW (Hence the restriction on not using the maximum
// ELEN)
MVT WideVT =
MVT::getVectorVT(MVT::getIntegerVT(VecVT.getScalarSizeInBits() * 2),
VecVT.getVectorElementCount());
MVT WideContainerVT = WideVT; // <vscale x n x ty*2>
if (WideContainerVT.isFixedLengthVector())
WideContainerVT = getContainerForFixedLengthVector(DAG, WideVT, Subtarget);
// Bitcast the input vectors to integers in case they are FP
VecContainerVT = VecContainerVT.changeTypeToInteger();
EvenV = DAG.getBitcast(VecContainerVT, EvenV);
OddV = DAG.getBitcast(VecContainerVT, OddV);
auto [Mask, VL] = getDefaultVLOps(VecVT, VecContainerVT, DL, DAG, Subtarget);
SDValue Passthru = DAG.getUNDEF(WideContainerVT);
// Widen EvenV and OddV with 0s and add one copy of OddV to EvenV with
// vwaddu.vv
SDValue Interleaved = DAG.getNode(RISCVISD::VWADDU_VL, DL, WideContainerVT,
EvenV, OddV, Passthru, Mask, VL);
// Then get OddV * by 2^(VecVT.getScalarSizeInBits() - 1)
SDValue AllOnesVec = DAG.getSplatVector(
VecContainerVT, DL, DAG.getAllOnesConstant(DL, Subtarget.getXLenVT()));
SDValue OddsMul = DAG.getNode(RISCVISD::VWMULU_VL, DL, WideContainerVT, OddV,
AllOnesVec, Passthru, Mask, VL);
// Add the two together so we get
// (OddV * 0xff...ff) + (OddV + EvenV)
// = (OddV * 0x100...00) + EvenV
// = (OddV << VecVT.getScalarSizeInBits()) + EvenV
// Note the ADD_VL and VLMULU_VL should get selected as vwmaccu.vx
Interleaved = DAG.getNode(RISCVISD::ADD_VL, DL, WideContainerVT, Interleaved,
OddsMul, Passthru, Mask, VL);
// Bitcast from <vscale x n * ty*2> to <vscale x 2*n x ty>
MVT ResultContainerVT = MVT::getVectorVT(
VecVT.getVectorElementType(), // Make sure to use original type
VecContainerVT.getVectorElementCount().multiplyCoefficientBy(2));
Interleaved = DAG.getBitcast(ResultContainerVT, Interleaved);
// Convert back to a fixed vector if needed
MVT ResultVT =
MVT::getVectorVT(VecVT.getVectorElementType(),
VecVT.getVectorElementCount().multiplyCoefficientBy(2));
if (ResultVT.isFixedLengthVector())
Interleaved =
convertFromScalableVector(ResultVT, Interleaved, DAG, Subtarget);
return Interleaved;
}
static SDValue lowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
SDValue V1 = Op.getOperand(0);
SDValue V2 = Op.getOperand(1);
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
MVT VT = Op.getSimpleValueType();
unsigned NumElts = VT.getVectorNumElements();
ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
MVT ContainerVT = getContainerForFixedLengthVector(DAG, VT, Subtarget);
auto [TrueMask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
if (SVN->isSplat()) {
const int Lane = SVN->getSplatIndex();
if (Lane >= 0) {
MVT SVT = VT.getVectorElementType();
// Turn splatted vector load into a strided load with an X0 stride.
SDValue V = V1;
// Peek through CONCAT_VECTORS as VectorCombine can concat a vector
// with undef.
// FIXME: Peek through INSERT_SUBVECTOR, EXTRACT_SUBVECTOR, bitcasts?
int Offset = Lane;
if (V.getOpcode() == ISD::CONCAT_VECTORS) {
int OpElements =
V.getOperand(0).getSimpleValueType().getVectorNumElements();
V = V.getOperand(Offset / OpElements);
Offset %= OpElements;
}
// We need to ensure the load isn't atomic or volatile.
if (ISD::isNormalLoad(V.getNode()) && cast<LoadSDNode>(V)->isSimple()) {
auto *Ld = cast<LoadSDNode>(V);
Offset *= SVT.getStoreSize();
SDValue NewAddr = DAG.getMemBasePlusOffset(Ld->getBasePtr(),
TypeSize::Fixed(Offset), DL);
// If this is SEW=64 on RV32, use a strided load with a stride of x0.
if (SVT.isInteger() && SVT.bitsGT(XLenVT)) {
SDVTList VTs = DAG.getVTList({ContainerVT, MVT::Other});
SDValue IntID =
DAG.getTargetConstant(Intrinsic::riscv_vlse, DL, XLenVT);
SDValue Ops[] = {Ld->getChain(),
IntID,
DAG.getUNDEF(ContainerVT),
NewAddr,
DAG.getRegister(RISCV::X0, XLenVT),
VL};
SDValue NewLoad = DAG.getMemIntrinsicNode(
ISD::INTRINSIC_W_CHAIN, DL, VTs, Ops, SVT,
DAG.getMachineFunction().getMachineMemOperand(
Ld->getMemOperand(), Offset, SVT.getStoreSize()));
DAG.makeEquivalentMemoryOrdering(Ld, NewLoad);
return convertFromScalableVector(VT, NewLoad, DAG, Subtarget);
}
// Otherwise use a scalar load and splat. This will give the best
// opportunity to fold a splat into the operation. ISel can turn it into
// the x0 strided load if we aren't able to fold away the select.
if (SVT.isFloatingPoint())
V = DAG.getLoad(SVT, DL, Ld->getChain(), NewAddr,
Ld->getPointerInfo().getWithOffset(Offset),
Ld->getOriginalAlign(),
Ld->getMemOperand()->getFlags());
else
V = DAG.getExtLoad(ISD::SEXTLOAD, DL, XLenVT, Ld->getChain(), NewAddr,
Ld->getPointerInfo().getWithOffset(Offset), SVT,
Ld->getOriginalAlign(),
Ld->getMemOperand()->getFlags());
DAG.makeEquivalentMemoryOrdering(Ld, V);
unsigned Opc =
VT.isFloatingPoint() ? RISCVISD::VFMV_V_F_VL : RISCVISD::VMV_V_X_VL;
SDValue Splat =
DAG.getNode(Opc, DL, ContainerVT, DAG.getUNDEF(ContainerVT), V, VL);
return convertFromScalableVector(VT, Splat, DAG, Subtarget);
}
V1 = convertToScalableVector(ContainerVT, V1, DAG, Subtarget);
assert(Lane < (int)NumElts && "Unexpected lane!");
SDValue Gather = DAG.getNode(RISCVISD::VRGATHER_VX_VL, DL, ContainerVT,
V1, DAG.getConstant(Lane, DL, XLenVT),
DAG.getUNDEF(ContainerVT), TrueMask, VL);
return convertFromScalableVector(VT, Gather, DAG, Subtarget);
}
}
ArrayRef<int> Mask = SVN->getMask();
if (SDValue V =
lowerVECTOR_SHUFFLEAsVSlidedown(DL, VT, V1, V2, Mask, Subtarget, DAG))
return V;
// Lower rotations to a SLIDEDOWN and a SLIDEUP. One of the source vectors may
// be undef which can be handled with a single SLIDEDOWN/UP.
int LoSrc, HiSrc;
int Rotation = isElementRotate(LoSrc, HiSrc, Mask);
if (Rotation > 0) {
SDValue LoV, HiV;
if (LoSrc >= 0) {
LoV = LoSrc == 0 ? V1 : V2;
LoV = convertToScalableVector(ContainerVT, LoV, DAG, Subtarget);
}
if (HiSrc >= 0) {
HiV = HiSrc == 0 ? V1 : V2;
HiV = convertToScalableVector(ContainerVT, HiV, DAG, Subtarget);
}
// We found a rotation. We need to slide HiV down by Rotation. Then we need
// to slide LoV up by (NumElts - Rotation).
unsigned InvRotate = NumElts - Rotation;
SDValue Res = DAG.getUNDEF(ContainerVT);
if (HiV) {
// If we are doing a SLIDEDOWN+SLIDEUP, reduce the VL for the SLIDEDOWN.
// FIXME: If we are only doing a SLIDEDOWN, don't reduce the VL as it
// causes multiple vsetvlis in some test cases such as lowering
// reduce.mul
SDValue DownVL = VL;
if (LoV)
DownVL = DAG.getConstant(InvRotate, DL, XLenVT);
Res = getVSlidedown(DAG, Subtarget, DL, ContainerVT, Res, HiV,
DAG.getConstant(Rotation, DL, XLenVT), TrueMask,
DownVL);
}
if (LoV)
Res = getVSlideup(DAG, Subtarget, DL, ContainerVT, Res, LoV,
DAG.getConstant(InvRotate, DL, XLenVT), TrueMask, VL,
RISCVII::TAIL_AGNOSTIC);
return convertFromScalableVector(VT, Res, DAG, Subtarget);
}
// If this is a deinterleave and we can widen the vector, then we can use
// vnsrl to deinterleave.
if (isDeinterleaveShuffle(VT, ContainerVT, V1, V2, Mask, Subtarget)) {
return getDeinterleaveViaVNSRL(DL, VT, V1.getOperand(0), Mask[0] == 0,
Subtarget, DAG);
}
// Detect an interleave shuffle and lower to
// (vmaccu.vx (vwaddu.vx lohalf(V1), lohalf(V2)), lohalf(V2), (2^eltbits - 1))
int EvenSrc, OddSrc;
if (isInterleaveShuffle(Mask, VT, EvenSrc, OddSrc, Subtarget)) {
// Extract the halves of the vectors.
MVT HalfVT = VT.getHalfNumVectorElementsVT();
int Size = Mask.size();
SDValue EvenV, OddV;
assert(EvenSrc >= 0 && "Undef source?");
EvenV = (EvenSrc / Size) == 0 ? V1 : V2;
EvenV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, HalfVT, EvenV,
DAG.getConstant(EvenSrc % Size, DL, XLenVT));
assert(OddSrc >= 0 && "Undef source?");
OddV = (OddSrc / Size) == 0 ? V1 : V2;
OddV = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, HalfVT, OddV,
DAG.getConstant(OddSrc % Size, DL, XLenVT));
return getWideningInterleave(EvenV, OddV, DL, DAG, Subtarget);
}
if (SDValue V =
lowerVECTOR_SHUFFLEAsVSlideup(DL, VT, V1, V2, Mask, Subtarget, DAG))
return V;
// Detect shuffles which can be re-expressed as vector selects; these are
// shuffles in which each element in the destination is taken from an element
// at the corresponding index in either source vectors.
bool IsSelect = all_of(enumerate(Mask), [&](const auto &MaskIdx) {
int MaskIndex = MaskIdx.value();
return MaskIndex < 0 || MaskIdx.index() == (unsigned)MaskIndex % NumElts;
});
assert(!V1.isUndef() && "Unexpected shuffle canonicalization");
SmallVector<SDValue> MaskVals;
// As a backup, shuffles can be lowered via a vrgather instruction, possibly
// merged with a second vrgather.
SmallVector<SDValue> GatherIndicesLHS, GatherIndicesRHS;
// By default we preserve the original operand order, and use a mask to
// select LHS as true and RHS as false. However, since RVV vector selects may
// feature splats but only on the LHS, we may choose to invert our mask and
// instead select between RHS and LHS.
bool SwapOps = DAG.isSplatValue(V2) && !DAG.isSplatValue(V1);
bool InvertMask = IsSelect == SwapOps;
// Keep a track of which non-undef indices are used by each LHS/RHS shuffle
// half.
DenseMap<int, unsigned> LHSIndexCounts, RHSIndexCounts;
// Now construct the mask that will be used by the vselect or blended
// vrgather operation. For vrgathers, construct the appropriate indices into
// each vector.
for (int MaskIndex : Mask) {
bool SelectMaskVal = (MaskIndex < (int)NumElts) ^ InvertMask;
MaskVals.push_back(DAG.getConstant(SelectMaskVal, DL, XLenVT));
if (!IsSelect) {
bool IsLHSOrUndefIndex = MaskIndex < (int)NumElts;
GatherIndicesLHS.push_back(IsLHSOrUndefIndex && MaskIndex >= 0
? DAG.getConstant(MaskIndex, DL, XLenVT)
: DAG.getUNDEF(XLenVT));
GatherIndicesRHS.push_back(
IsLHSOrUndefIndex ? DAG.getUNDEF(XLenVT)
: DAG.getConstant(MaskIndex - NumElts, DL, XLenVT));
if (IsLHSOrUndefIndex && MaskIndex >= 0)
++LHSIndexCounts[MaskIndex];
if (!IsLHSOrUndefIndex)
++RHSIndexCounts[MaskIndex - NumElts];
}
}
if (SwapOps) {
std::swap(V1, V2);
std::swap(GatherIndicesLHS, GatherIndicesRHS);
}
assert(MaskVals.size() == NumElts && "Unexpected select-like shuffle");
MVT MaskVT = MVT::getVectorVT(MVT::i1, NumElts);
SDValue SelectMask = DAG.getBuildVector(MaskVT, DL, MaskVals);
if (IsSelect)
return DAG.getNode(ISD::VSELECT, DL, VT, SelectMask, V1, V2);
if (VT.getScalarSizeInBits() == 8 && VT.getVectorNumElements() > 256) {
// On such a large vector we're unable to use i8 as the index type.
// FIXME: We could promote the index to i16 and use vrgatherei16, but that
// may involve vector splitting if we're already at LMUL=8, or our
// user-supplied maximum fixed-length LMUL.
return SDValue();
}
unsigned GatherVXOpc = RISCVISD::VRGATHER_VX_VL;
unsigned GatherVVOpc = RISCVISD::VRGATHER_VV_VL;
MVT IndexVT = VT.changeTypeToInteger();
// Since we can't introduce illegal index types at this stage, use i16 and
// vrgatherei16 if the corresponding index type for plain vrgather is greater
// than XLenVT.
if (IndexVT.getScalarType().bitsGT(XLenVT)) {
GatherVVOpc = RISCVISD::VRGATHEREI16_VV_VL;
IndexVT = IndexVT.changeVectorElementType(MVT::i16);
}
MVT IndexContainerVT =
ContainerVT.changeVectorElementType(IndexVT.getScalarType());
SDValue Gather;
// TODO: This doesn't trigger for i64 vectors on RV32, since there we
// encounter a bitcasted BUILD_VECTOR with low/high i32 values.
if (SDValue SplatValue = DAG.getSplatValue(V1, /*LegalTypes*/ true)) {
Gather = lowerScalarSplat(SDValue(), SplatValue, VL, ContainerVT, DL, DAG,
Subtarget);
} else {
V1 = convertToScalableVector(ContainerVT, V1, DAG, Subtarget);
// If only one index is used, we can use a "splat" vrgather.
// TODO: We can splat the most-common index and fix-up any stragglers, if
// that's beneficial.
if (LHSIndexCounts.size() == 1) {
int SplatIndex = LHSIndexCounts.begin()->getFirst();
Gather = DAG.getNode(GatherVXOpc, DL, ContainerVT, V1,
DAG.getConstant(SplatIndex, DL, XLenVT),
DAG.getUNDEF(ContainerVT), TrueMask, VL);
} else {
SDValue LHSIndices = DAG.getBuildVector(IndexVT, DL, GatherIndicesLHS);
LHSIndices =
convertToScalableVector(IndexContainerVT, LHSIndices, DAG, Subtarget);
Gather = DAG.getNode(GatherVVOpc, DL, ContainerVT, V1, LHSIndices,
DAG.getUNDEF(ContainerVT), TrueMask, VL);
}
}
// If a second vector operand is used by this shuffle, blend it in with an
// additional vrgather.
if (!V2.isUndef()) {
V2 = convertToScalableVector(ContainerVT, V2, DAG, Subtarget);
MVT MaskContainerVT = ContainerVT.changeVectorElementType(MVT::i1);
SelectMask =
convertToScalableVector(MaskContainerVT, SelectMask, DAG, Subtarget);
// If only one index is used, we can use a "splat" vrgather.
// TODO: We can splat the most-common index and fix-up any stragglers, if
// that's beneficial.
if (RHSIndexCounts.size() == 1) {
int SplatIndex = RHSIndexCounts.begin()->getFirst();
Gather = DAG.getNode(GatherVXOpc, DL, ContainerVT, V2,
DAG.getConstant(SplatIndex, DL, XLenVT), Gather,
SelectMask, VL);
} else {
SDValue RHSIndices = DAG.getBuildVector(IndexVT, DL, GatherIndicesRHS);
RHSIndices =
convertToScalableVector(IndexContainerVT, RHSIndices, DAG, Subtarget);
Gather = DAG.getNode(GatherVVOpc, DL, ContainerVT, V2, RHSIndices, Gather,
SelectMask, VL);
}
}
return convertFromScalableVector(VT, Gather, DAG, Subtarget);
}
bool RISCVTargetLowering::isShuffleMaskLegal(ArrayRef<int> M, EVT VT) const {
// Support splats for any type. These should type legalize well.
if (ShuffleVectorSDNode::isSplatMask(M.data(), VT))
return true;
// Only support legal VTs for other shuffles for now.
if (!isTypeLegal(VT))
return false;
MVT SVT = VT.getSimpleVT();
int Dummy1, Dummy2;
return (isElementRotate(Dummy1, Dummy2, M) > 0) ||
isInterleaveShuffle(M, SVT, Dummy1, Dummy2, Subtarget);
}
// Lower CTLZ_ZERO_UNDEF or CTTZ_ZERO_UNDEF by converting to FP and extracting
// the exponent.
SDValue
RISCVTargetLowering::lowerCTLZ_CTTZ_ZERO_UNDEF(SDValue Op,
SelectionDAG &DAG) const {
MVT VT = Op.getSimpleValueType();
unsigned EltSize = VT.getScalarSizeInBits();
SDValue Src = Op.getOperand(0);
SDLoc DL(Op);
// We choose FP type that can represent the value if possible. Otherwise, we
// use rounding to zero conversion for correct exponent of the result.
// TODO: Use f16 for i8 when possible?
MVT FloatEltVT = (EltSize >= 32) ? MVT::f64 : MVT::f32;
if (!isTypeLegal(MVT::getVectorVT(FloatEltVT, VT.getVectorElementCount())))
FloatEltVT = MVT::f32;
MVT FloatVT = MVT::getVectorVT(FloatEltVT, VT.getVectorElementCount());
// Legal types should have been checked in the RISCVTargetLowering
// constructor.
// TODO: Splitting may make sense in some cases.
assert(DAG.getTargetLoweringInfo().isTypeLegal(FloatVT) &&
"Expected legal float type!");
// For CTTZ_ZERO_UNDEF, we need to extract the lowest set bit using X & -X.
// The trailing zero count is equal to log2 of this single bit value.
if (Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF) {
SDValue Neg = DAG.getNegative(Src, DL, VT);
Src = DAG.getNode(ISD::AND, DL, VT, Src, Neg);
}
// We have a legal FP type, convert to it.
SDValue FloatVal;
if (FloatVT.bitsGT(VT)) {
FloatVal = DAG.getNode(ISD::UINT_TO_FP, DL, FloatVT, Src);
} else {
// Use RTZ to avoid rounding influencing exponent of FloatVal.
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
Src = convertToScalableVector(ContainerVT, Src, DAG, Subtarget);
}
auto [Mask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
SDValue RTZRM =
DAG.getTargetConstant(RISCVFPRndMode::RTZ, DL, Subtarget.getXLenVT());
MVT ContainerFloatVT =
MVT::getVectorVT(FloatEltVT, ContainerVT.getVectorElementCount());
FloatVal = DAG.getNode(RISCVISD::VFCVT_RM_F_XU_VL, DL, ContainerFloatVT,
Src, Mask, RTZRM, VL);
if (VT.isFixedLengthVector())
FloatVal = convertFromScalableVector(FloatVT, FloatVal, DAG, Subtarget);
}
// Bitcast to integer and shift the exponent to the LSB.
EVT IntVT = FloatVT.changeVectorElementTypeToInteger();
SDValue Bitcast = DAG.getBitcast(IntVT, FloatVal);
unsigned ShiftAmt = FloatEltVT == MVT::f64 ? 52 : 23;
SDValue Exp = DAG.getNode(ISD::SRL, DL, IntVT, Bitcast,
DAG.getConstant(ShiftAmt, DL, IntVT));
// Restore back to original type. Truncation after SRL is to generate vnsrl.
if (IntVT.bitsLT(VT))
Exp = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Exp);
else if (IntVT.bitsGT(VT))
Exp = DAG.getNode(ISD::TRUNCATE, DL, VT, Exp);
// The exponent contains log2 of the value in biased form.
unsigned ExponentBias = FloatEltVT == MVT::f64 ? 1023 : 127;
// For trailing zeros, we just need to subtract the bias.
if (Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF)
return DAG.getNode(ISD::SUB, DL, VT, Exp,
DAG.getConstant(ExponentBias, DL, VT));
// For leading zeros, we need to remove the bias and convert from log2 to
// leading zeros. We can do this by subtracting from (Bias + (EltSize - 1)).
unsigned Adjust = ExponentBias + (EltSize - 1);
SDValue Res =
DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(Adjust, DL, VT), Exp);
// The above result with zero input equals to Adjust which is greater than
// EltSize. Hence, we can do min(Res, EltSize) for CTLZ.
if (Op.getOpcode() == ISD::CTLZ)
Res = DAG.getNode(ISD::UMIN, DL, VT, Res, DAG.getConstant(EltSize, DL, VT));
return Res;
}
// While RVV has alignment restrictions, we should always be able to load as a
// legal equivalently-sized byte-typed vector instead. This method is
// responsible for re-expressing a ISD::LOAD via a correctly-aligned type. If
// the load is already correctly-aligned, it returns SDValue().
SDValue RISCVTargetLowering::expandUnalignedRVVLoad(SDValue Op,
SelectionDAG &DAG) const {
auto *Load = cast<LoadSDNode>(Op);
assert(Load && Load->getMemoryVT().isVector() && "Expected vector load");
if (allowsMemoryAccessForAlignment(*DAG.getContext(), DAG.getDataLayout(),
Load->getMemoryVT(),
*Load->getMemOperand()))
return SDValue();
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
unsigned EltSizeBits = VT.getScalarSizeInBits();
assert((EltSizeBits == 16 || EltSizeBits == 32 || EltSizeBits == 64) &&
"Unexpected unaligned RVV load type");
MVT NewVT =
MVT::getVectorVT(MVT::i8, VT.getVectorElementCount() * (EltSizeBits / 8));
assert(NewVT.isValid() &&
"Expecting equally-sized RVV vector types to be legal");
SDValue L = DAG.getLoad(NewVT, DL, Load->getChain(), Load->getBasePtr(),
Load->getPointerInfo(), Load->getOriginalAlign(),
Load->getMemOperand()->getFlags());
return DAG.getMergeValues({DAG.getBitcast(VT, L), L.getValue(1)}, DL);
}
// While RVV has alignment restrictions, we should always be able to store as a
// legal equivalently-sized byte-typed vector instead. This method is
// responsible for re-expressing a ISD::STORE via a correctly-aligned type. It
// returns SDValue() if the store is already correctly aligned.
SDValue RISCVTargetLowering::expandUnalignedRVVStore(SDValue Op,
SelectionDAG &DAG) const {
auto *Store = cast<StoreSDNode>(Op);
assert(Store && Store->getValue().getValueType().isVector() &&
"Expected vector store");
if (allowsMemoryAccessForAlignment(*DAG.getContext(), DAG.getDataLayout(),
Store->getMemoryVT(),
*Store->getMemOperand()))
return SDValue();
SDLoc DL(Op);
SDValue StoredVal = Store->getValue();
MVT VT = StoredVal.getSimpleValueType();
unsigned EltSizeBits = VT.getScalarSizeInBits();
assert((EltSizeBits == 16 || EltSizeBits == 32 || EltSizeBits == 64) &&
"Unexpected unaligned RVV store type");
MVT NewVT =
MVT::getVectorVT(MVT::i8, VT.getVectorElementCount() * (EltSizeBits / 8));
assert(NewVT.isValid() &&
"Expecting equally-sized RVV vector types to be legal");
StoredVal = DAG.getBitcast(NewVT, StoredVal);
return DAG.getStore(Store->getChain(), DL, StoredVal, Store->getBasePtr(),
Store->getPointerInfo(), Store->getOriginalAlign(),
Store->getMemOperand()->getFlags());
}
static SDValue lowerConstant(SDValue Op, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
assert(Op.getValueType() == MVT::i64 && "Unexpected VT");
int64_t Imm = cast<ConstantSDNode>(Op)->getSExtValue();
// All simm32 constants should be handled by isel.
// NOTE: The getMaxBuildIntsCost call below should return a value >= 2 making
// this check redundant, but small immediates are common so this check
// should have better compile time.
if (isInt<32>(Imm))
return Op;
// We only need to cost the immediate, if constant pool lowering is enabled.
if (!Subtarget.useConstantPoolForLargeInts())
return Op;
RISCVMatInt::InstSeq Seq =
RISCVMatInt::generateInstSeq(Imm, Subtarget.getFeatureBits());
if (Seq.size() <= Subtarget.getMaxBuildIntsCost())
return Op;
// Expand to a constant pool using the default expansion code.
return SDValue();
}
static SDValue LowerATOMIC_FENCE(SDValue Op, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
SDLoc dl(Op);
AtomicOrdering FenceOrdering =
static_cast<AtomicOrdering>(Op.getConstantOperandVal(1));
SyncScope::ID FenceSSID =
static_cast<SyncScope::ID>(Op.getConstantOperandVal(2));
if (Subtarget.hasStdExtZtso()) {
// The only fence that needs an instruction is a sequentially-consistent
// cross-thread fence.
if (FenceOrdering == AtomicOrdering::SequentiallyConsistent &&
FenceSSID == SyncScope::System)
return Op;
// MEMBARRIER is a compiler barrier; it codegens to a no-op.
return DAG.getNode(ISD::MEMBARRIER, dl, MVT::Other, Op.getOperand(0));
}
// singlethread fences only synchronize with signal handlers on the same
// thread and thus only need to preserve instruction order, not actually
// enforce memory ordering.
if (FenceSSID == SyncScope::SingleThread)
// MEMBARRIER is a compiler barrier; it codegens to a no-op.
return DAG.getNode(ISD::MEMBARRIER, dl, MVT::Other, Op.getOperand(0));
return Op;
}
SDValue RISCVTargetLowering::LowerOperation(SDValue Op,
SelectionDAG &DAG) const {
switch (Op.getOpcode()) {
default:
report_fatal_error("unimplemented operand");
case ISD::ATOMIC_FENCE:
return LowerATOMIC_FENCE(Op, DAG, Subtarget);
case ISD::GlobalAddress:
return lowerGlobalAddress(Op, DAG);
case ISD::BlockAddress:
return lowerBlockAddress(Op, DAG);
case ISD::ConstantPool:
return lowerConstantPool(Op, DAG);
case ISD::JumpTable:
return lowerJumpTable(Op, DAG);
case ISD::GlobalTLSAddress:
return lowerGlobalTLSAddress(Op, DAG);
case ISD::Constant:
return lowerConstant(Op, DAG, Subtarget);
case ISD::SELECT:
return lowerSELECT(Op, DAG);
case ISD::BRCOND:
return lowerBRCOND(Op, DAG);
case ISD::VASTART:
return lowerVASTART(Op, DAG);
case ISD::FRAMEADDR:
return lowerFRAMEADDR(Op, DAG);
case ISD::RETURNADDR:
return lowerRETURNADDR(Op, DAG);
case ISD::SHL_PARTS:
return lowerShiftLeftParts(Op, DAG);
case ISD::SRA_PARTS:
return lowerShiftRightParts(Op, DAG, true);
case ISD::SRL_PARTS:
return lowerShiftRightParts(Op, DAG, false);
case ISD::BITCAST: {
SDLoc DL(Op);
EVT VT = Op.getValueType();
SDValue Op0 = Op.getOperand(0);
EVT Op0VT = Op0.getValueType();
MVT XLenVT = Subtarget.getXLenVT();
if (VT == MVT::f16 && Op0VT == MVT::i16 &&
Subtarget.hasStdExtZfhOrZfhmin()) {
SDValue NewOp0 = DAG.getNode(ISD::ANY_EXTEND, DL, XLenVT, Op0);
SDValue FPConv = DAG.getNode(RISCVISD::FMV_H_X, DL, MVT::f16, NewOp0);
return FPConv;
}
if (VT == MVT::f32 && Op0VT == MVT::i32 && Subtarget.is64Bit() &&
Subtarget.hasStdExtF()) {
SDValue NewOp0 = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, Op0);
SDValue FPConv =
DAG.getNode(RISCVISD::FMV_W_X_RV64, DL, MVT::f32, NewOp0);
return FPConv;
}
if (VT == MVT::f64 && Op0VT == MVT::i64 && XLenVT == MVT::i32 &&
Subtarget.hasStdExtZfa()) {
SDValue Lo, Hi;
std::tie(Lo, Hi) = DAG.SplitScalar(Op0, DL, MVT::i32, MVT::i32);
SDValue RetReg =
DAG.getNode(RISCVISD::BuildPairF64, DL, MVT::f64, Lo, Hi);
return RetReg;
}
// Consider other scalar<->scalar casts as legal if the types are legal.
// Otherwise expand them.
if (!VT.isVector() && !Op0VT.isVector()) {
if (isTypeLegal(VT) && isTypeLegal(Op0VT))
return Op;
return SDValue();
}
assert(!VT.isScalableVector() && !Op0VT.isScalableVector() &&
"Unexpected types");
if (VT.isFixedLengthVector()) {
// We can handle fixed length vector bitcasts with a simple replacement
// in isel.
if (Op0VT.isFixedLengthVector())
return Op;
// When bitcasting from scalar to fixed-length vector, insert the scalar
// into a one-element vector of the result type, and perform a vector
// bitcast.
if (!Op0VT.isVector()) {
EVT BVT = EVT::getVectorVT(*DAG.getContext(), Op0VT, 1);
if (!isTypeLegal(BVT))
return SDValue();
return DAG.getBitcast(VT, DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, BVT,
DAG.getUNDEF(BVT), Op0,
DAG.getConstant(0, DL, XLenVT)));
}
return SDValue();
}
// Custom-legalize bitcasts from fixed-length vector types to scalar types
// thus: bitcast the vector to a one-element vector type whose element type
// is the same as the result type, and extract the first element.
if (!VT.isVector() && Op0VT.isFixedLengthVector()) {
EVT BVT = EVT::getVectorVT(*DAG.getContext(), VT, 1);
if (!isTypeLegal(BVT))
return SDValue();
SDValue BVec = DAG.getBitcast(BVT, Op0);
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, BVec,
DAG.getConstant(0, DL, XLenVT));
}
return SDValue();
}
case ISD::INTRINSIC_WO_CHAIN:
return LowerINTRINSIC_WO_CHAIN(Op, DAG);
case ISD::INTRINSIC_W_CHAIN:
return LowerINTRINSIC_W_CHAIN(Op, DAG);
case ISD::INTRINSIC_VOID:
return LowerINTRINSIC_VOID(Op, DAG);
case ISD::BITREVERSE: {
MVT VT = Op.getSimpleValueType();
SDLoc DL(Op);
assert(Subtarget.hasStdExtZbkb() && "Unexpected custom legalization");
assert(Op.getOpcode() == ISD::BITREVERSE && "Unexpected opcode");
// Expand bitreverse to a bswap(rev8) followed by brev8.
SDValue BSwap = DAG.getNode(ISD::BSWAP, DL, VT, Op.getOperand(0));
return DAG.getNode(RISCVISD::BREV8, DL, VT, BSwap);
}
case ISD::TRUNCATE:
// Only custom-lower vector truncates
if (!Op.getSimpleValueType().isVector())
return Op;
return lowerVectorTruncLike(Op, DAG);
case ISD::ANY_EXTEND:
case ISD::ZERO_EXTEND:
if (Op.getOperand(0).getValueType().isVector() &&
Op.getOperand(0).getValueType().getVectorElementType() == MVT::i1)
return lowerVectorMaskExt(Op, DAG, /*ExtVal*/ 1);
return lowerFixedLengthVectorExtendToRVV(Op, DAG, RISCVISD::VZEXT_VL);
case ISD::SIGN_EXTEND:
if (Op.getOperand(0).getValueType().isVector() &&
Op.getOperand(0).getValueType().getVectorElementType() == MVT::i1)
return lowerVectorMaskExt(Op, DAG, /*ExtVal*/ -1);
return lowerFixedLengthVectorExtendToRVV(Op, DAG, RISCVISD::VSEXT_VL);
case ISD::SPLAT_VECTOR_PARTS:
return lowerSPLAT_VECTOR_PARTS(Op, DAG);
case ISD::INSERT_VECTOR_ELT:
return lowerINSERT_VECTOR_ELT(Op, DAG);
case ISD::EXTRACT_VECTOR_ELT:
return lowerEXTRACT_VECTOR_ELT(Op, DAG);
case ISD::SCALAR_TO_VECTOR: {
MVT VT = Op.getSimpleValueType();
SDLoc DL(Op);
SDValue Scalar = Op.getOperand(0);
if (VT.getVectorElementType() == MVT::i1) {
MVT WideVT = VT.changeVectorElementType(MVT::i8);
SDValue V = DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, WideVT, Scalar);
return DAG.getNode(ISD::TRUNCATE, DL, VT, V);
}
MVT ContainerVT = VT;
if (VT.isFixedLengthVector())
ContainerVT = getContainerForFixedLengthVector(VT);
SDValue VL = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).second;
SDValue V = DAG.getNode(RISCVISD::VMV_S_X_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), Scalar, VL);
if (VT.isFixedLengthVector())
V = convertFromScalableVector(VT, V, DAG, Subtarget);
return V;
}
case ISD::VSCALE: {
MVT VT = Op.getSimpleValueType();
SDLoc DL(Op);
SDValue VLENB = DAG.getNode(RISCVISD::READ_VLENB, DL, VT);
// We define our scalable vector types for lmul=1 to use a 64 bit known
// minimum size. e.g. <vscale x 2 x i32>. VLENB is in bytes so we calculate
// vscale as VLENB / 8.
static_assert(RISCV::RVVBitsPerBlock == 64, "Unexpected bits per block!");
if (Subtarget.getRealMinVLen() < RISCV::RVVBitsPerBlock)
report_fatal_error("Support for VLEN==32 is incomplete.");
// We assume VLENB is a multiple of 8. We manually choose the best shift
// here because SimplifyDemandedBits isn't always able to simplify it.
uint64_t Val = Op.getConstantOperandVal(0);
if (isPowerOf2_64(Val)) {
uint64_t Log2 = Log2_64(Val);
if (Log2 < 3)
return DAG.getNode(ISD::SRL, DL, VT, VLENB,
DAG.getConstant(3 - Log2, DL, VT));
if (Log2 > 3)
return DAG.getNode(ISD::SHL, DL, VT, VLENB,
DAG.getConstant(Log2 - 3, DL, VT));
return VLENB;
}
// If the multiplier is a multiple of 8, scale it down to avoid needing
// to shift the VLENB value.
if ((Val % 8) == 0)
return DAG.getNode(ISD::MUL, DL, VT, VLENB,
DAG.getConstant(Val / 8, DL, VT));
SDValue VScale = DAG.getNode(ISD::SRL, DL, VT, VLENB,
DAG.getConstant(3, DL, VT));
return DAG.getNode(ISD::MUL, DL, VT, VScale, Op.getOperand(0));
}
case ISD::FPOWI: {
// Custom promote f16 powi with illegal i32 integer type on RV64. Once
// promoted this will be legalized into a libcall by LegalizeIntegerTypes.
if (Op.getValueType() == MVT::f16 && Subtarget.is64Bit() &&
Op.getOperand(1).getValueType() == MVT::i32) {
SDLoc DL(Op);
SDValue Op0 = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Op.getOperand(0));
SDValue Powi =
DAG.getNode(ISD::FPOWI, DL, MVT::f32, Op0, Op.getOperand(1));
return DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, Powi,
DAG.getIntPtrConstant(0, DL, /*isTarget=*/true));
}
return SDValue();
}
case ISD::FP_EXTEND:
case ISD::FP_ROUND:
if (!Op.getValueType().isVector())
return Op;
return lowerVectorFPExtendOrRoundLike(Op, DAG);
case ISD::STRICT_FP_ROUND:
case ISD::STRICT_FP_EXTEND:
return lowerStrictFPExtendOrRoundLike(Op, DAG);
case ISD::FP_TO_SINT:
case ISD::FP_TO_UINT:
case ISD::SINT_TO_FP:
case ISD::UINT_TO_FP:
case ISD::STRICT_FP_TO_SINT:
case ISD::STRICT_FP_TO_UINT:
case ISD::STRICT_SINT_TO_FP:
case ISD::STRICT_UINT_TO_FP: {
// RVV can only do fp<->int conversions to types half/double the size as
// the source. We custom-lower any conversions that do two hops into
// sequences.
MVT VT = Op.getSimpleValueType();
if (!VT.isVector())
return Op;
SDLoc DL(Op);
bool IsStrict = Op->isStrictFPOpcode();
SDValue Src = Op.getOperand(0 + IsStrict);
MVT EltVT = VT.getVectorElementType();
MVT SrcVT = Src.getSimpleValueType();
MVT SrcEltVT = SrcVT.getVectorElementType();
unsigned EltSize = EltVT.getSizeInBits();
unsigned SrcEltSize = SrcEltVT.getSizeInBits();
assert(isPowerOf2_32(EltSize) && isPowerOf2_32(SrcEltSize) &&
"Unexpected vector element types");
bool IsInt2FP = SrcEltVT.isInteger();
// Widening conversions
if (EltSize > (2 * SrcEltSize)) {
if (IsInt2FP) {
// Do a regular integer sign/zero extension then convert to float.
MVT IVecVT = MVT::getVectorVT(MVT::getIntegerVT(EltSize / 2),
VT.getVectorElementCount());
unsigned ExtOpcode = (Op.getOpcode() == ISD::UINT_TO_FP ||
Op.getOpcode() == ISD::STRICT_UINT_TO_FP)
? ISD::ZERO_EXTEND
: ISD::SIGN_EXTEND;
SDValue Ext = DAG.getNode(ExtOpcode, DL, IVecVT, Src);
if (IsStrict)
return DAG.getNode(Op.getOpcode(), DL, Op->getVTList(),
Op.getOperand(0), Ext);
return DAG.getNode(Op.getOpcode(), DL, VT, Ext);
}
// FP2Int
assert(SrcEltVT == MVT::f16 && "Unexpected FP_TO_[US]INT lowering");
// Do one doubling fp_extend then complete the operation by converting
// to int.
MVT InterimFVT = MVT::getVectorVT(MVT::f32, VT.getVectorElementCount());
if (IsStrict) {
auto [FExt, Chain] =
DAG.getStrictFPExtendOrRound(Src, Op.getOperand(0), DL, InterimFVT);
return DAG.getNode(Op.getOpcode(), DL, Op->getVTList(), Chain, FExt);
}
SDValue FExt = DAG.getFPExtendOrRound(Src, DL, InterimFVT);
return DAG.getNode(Op.getOpcode(), DL, VT, FExt);
}
// Narrowing conversions
if (SrcEltSize > (2 * EltSize)) {
if (IsInt2FP) {
// One narrowing int_to_fp, then an fp_round.
assert(EltVT == MVT::f16 && "Unexpected [US]_TO_FP lowering");
MVT InterimFVT = MVT::getVectorVT(MVT::f32, VT.getVectorElementCount());
if (IsStrict) {
SDValue Int2FP = DAG.getNode(Op.getOpcode(), DL,
DAG.getVTList(InterimFVT, MVT::Other),
Op.getOperand(0), Src);
SDValue Chain = Int2FP.getValue(1);
return DAG.getStrictFPExtendOrRound(Int2FP, Chain, DL, VT).first;
}
SDValue Int2FP = DAG.getNode(Op.getOpcode(), DL, InterimFVT, Src);
return DAG.getFPExtendOrRound(Int2FP, DL, VT);
}
// FP2Int
// One narrowing fp_to_int, then truncate the integer. If the float isn't
// representable by the integer, the result is poison.
MVT IVecVT = MVT::getVectorVT(MVT::getIntegerVT(SrcEltSize / 2),
VT.getVectorElementCount());
if (IsStrict) {
SDValue FP2Int =
DAG.getNode(Op.getOpcode(), DL, DAG.getVTList(IVecVT, MVT::Other),
Op.getOperand(0), Src);
SDValue Res = DAG.getNode(ISD::TRUNCATE, DL, VT, FP2Int);
return DAG.getMergeValues({Res, FP2Int.getValue(1)}, DL);
}
SDValue FP2Int = DAG.getNode(Op.getOpcode(), DL, IVecVT, Src);
return DAG.getNode(ISD::TRUNCATE, DL, VT, FP2Int);
}
// Scalable vectors can exit here. Patterns will handle equally-sized
// conversions halving/doubling ones.
if (!VT.isFixedLengthVector())
return Op;
// For fixed-length vectors we lower to a custom "VL" node.
unsigned RVVOpc = 0;
switch (Op.getOpcode()) {
default:
llvm_unreachable("Impossible opcode");
case ISD::FP_TO_SINT:
RVVOpc = RISCVISD::VFCVT_RTZ_X_F_VL;
break;
case ISD::FP_TO_UINT:
RVVOpc = RISCVISD::VFCVT_RTZ_XU_F_VL;
break;
case ISD::SINT_TO_FP:
RVVOpc = RISCVISD::SINT_TO_FP_VL;
break;
case ISD::UINT_TO_FP:
RVVOpc = RISCVISD::UINT_TO_FP_VL;
break;
case ISD::STRICT_FP_TO_SINT:
RVVOpc = RISCVISD::STRICT_VFCVT_RTZ_X_F_VL;
break;
case ISD::STRICT_FP_TO_UINT:
RVVOpc = RISCVISD::STRICT_VFCVT_RTZ_XU_F_VL;
break;
case ISD::STRICT_SINT_TO_FP:
RVVOpc = RISCVISD::STRICT_SINT_TO_FP_VL;
break;
case ISD::STRICT_UINT_TO_FP:
RVVOpc = RISCVISD::STRICT_UINT_TO_FP_VL;
break;
}
MVT ContainerVT = getContainerForFixedLengthVector(VT);
MVT SrcContainerVT = getContainerForFixedLengthVector(SrcVT);
assert(ContainerVT.getVectorElementCount() == SrcContainerVT.getVectorElementCount() &&
"Expected same element count");
auto [Mask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
Src = convertToScalableVector(SrcContainerVT, Src, DAG, Subtarget);
if (IsStrict) {
Src = DAG.getNode(RVVOpc, DL, DAG.getVTList(ContainerVT, MVT::Other),
Op.getOperand(0), Src, Mask, VL);
SDValue SubVec = convertFromScalableVector(VT, Src, DAG, Subtarget);
return DAG.getMergeValues({SubVec, Src.getValue(1)}, DL);
}
Src = DAG.getNode(RVVOpc, DL, ContainerVT, Src, Mask, VL);
return convertFromScalableVector(VT, Src, DAG, Subtarget);
}
case ISD::FP_TO_SINT_SAT:
case ISD::FP_TO_UINT_SAT:
return lowerFP_TO_INT_SAT(Op, DAG, Subtarget);
case ISD::FTRUNC:
case ISD::FCEIL:
case ISD::FFLOOR:
case ISD::FRINT:
case ISD::FROUND:
case ISD::FROUNDEVEN:
return lowerFTRUNC_FCEIL_FFLOOR_FROUND(Op, DAG, Subtarget);
case ISD::VECREDUCE_ADD:
case ISD::VECREDUCE_UMAX:
case ISD::VECREDUCE_SMAX:
case ISD::VECREDUCE_UMIN:
case ISD::VECREDUCE_SMIN:
return lowerVECREDUCE(Op, DAG);
case ISD::VECREDUCE_AND:
case ISD::VECREDUCE_OR:
case ISD::VECREDUCE_XOR:
if (Op.getOperand(0).getValueType().getVectorElementType() == MVT::i1)
return lowerVectorMaskVecReduction(Op, DAG, /*IsVP*/ false);
return lowerVECREDUCE(Op, DAG);
case ISD::VECREDUCE_FADD:
case ISD::VECREDUCE_SEQ_FADD:
case ISD::VECREDUCE_FMIN:
case ISD::VECREDUCE_FMAX:
return lowerFPVECREDUCE(Op, DAG);
case ISD::VP_REDUCE_ADD:
case ISD::VP_REDUCE_UMAX:
case ISD::VP_REDUCE_SMAX:
case ISD::VP_REDUCE_UMIN:
case ISD::VP_REDUCE_SMIN:
case ISD::VP_REDUCE_FADD:
case ISD::VP_REDUCE_SEQ_FADD:
case ISD::VP_REDUCE_FMIN:
case ISD::VP_REDUCE_FMAX:
return lowerVPREDUCE(Op, DAG);
case ISD::VP_REDUCE_AND:
case ISD::VP_REDUCE_OR:
case ISD::VP_REDUCE_XOR:
if (Op.getOperand(1).getValueType().getVectorElementType() == MVT::i1)
return lowerVectorMaskVecReduction(Op, DAG, /*IsVP*/ true);
return lowerVPREDUCE(Op, DAG);
case ISD::INSERT_SUBVECTOR:
return lowerINSERT_SUBVECTOR(Op, DAG);
case ISD::EXTRACT_SUBVECTOR:
return lowerEXTRACT_SUBVECTOR(Op, DAG);
case ISD::VECTOR_DEINTERLEAVE:
return lowerVECTOR_DEINTERLEAVE(Op, DAG);
case ISD::VECTOR_INTERLEAVE:
return lowerVECTOR_INTERLEAVE(Op, DAG);
case ISD::STEP_VECTOR:
return lowerSTEP_VECTOR(Op, DAG);
case ISD::VECTOR_REVERSE:
return lowerVECTOR_REVERSE(Op, DAG);
case ISD::VECTOR_SPLICE:
return lowerVECTOR_SPLICE(Op, DAG);
case ISD::BUILD_VECTOR:
return lowerBUILD_VECTOR(Op, DAG, Subtarget);
case ISD::SPLAT_VECTOR:
if (Op.getValueType().getVectorElementType() == MVT::i1)
return lowerVectorMaskSplat(Op, DAG);
return SDValue();
case ISD::VECTOR_SHUFFLE:
return lowerVECTOR_SHUFFLE(Op, DAG, Subtarget);
case ISD::CONCAT_VECTORS: {
// Split CONCAT_VECTORS into a series of INSERT_SUBVECTOR nodes. This is
// better than going through the stack, as the default expansion does.
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
unsigned NumOpElts =
Op.getOperand(0).getSimpleValueType().getVectorMinNumElements();
SDValue Vec = DAG.getUNDEF(VT);
for (const auto &OpIdx : enumerate(Op->ops())) {
SDValue SubVec = OpIdx.value();
// Don't insert undef subvectors.
if (SubVec.isUndef())
continue;
Vec = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT, Vec, SubVec,
DAG.getIntPtrConstant(OpIdx.index() * NumOpElts, DL));
}
return Vec;
}
case ISD::LOAD:
if (auto V = expandUnalignedRVVLoad(Op, DAG))
return V;
if (Op.getValueType().isFixedLengthVector())
return lowerFixedLengthVectorLoadToRVV(Op, DAG);
return Op;
case ISD::STORE:
if (auto V = expandUnalignedRVVStore(Op, DAG))
return V;
if (Op.getOperand(1).getValueType().isFixedLengthVector())
return lowerFixedLengthVectorStoreToRVV(Op, DAG);
return Op;
case ISD::MLOAD:
case ISD::VP_LOAD:
return lowerMaskedLoad(Op, DAG);
case ISD::MSTORE:
case ISD::VP_STORE:
return lowerMaskedStore(Op, DAG);
case ISD::SELECT_CC: {
// This occurs because we custom legalize SETGT and SETUGT for setcc. That
// causes LegalizeDAG to think we need to custom legalize select_cc. Expand
// into separate SETCC+SELECT_CC just like LegalizeDAG.
SDValue Tmp1 = Op.getOperand(0);
SDValue Tmp2 = Op.getOperand(1);
SDValue True = Op.getOperand(2);
SDValue False = Op.getOperand(3);
EVT VT = Op.getValueType();
SDValue CC = Op.getOperand(4);
EVT CmpVT = Tmp1.getValueType();
EVT CCVT =
getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), CmpVT);
SDLoc DL(Op);
SDValue Cond =
DAG.getNode(ISD::SETCC, DL, CCVT, Tmp1, Tmp2, CC, Op->getFlags());
return DAG.getSelect(DL, VT, Cond, True, False);
}
case ISD::SETCC: {
MVT OpVT = Op.getOperand(0).getSimpleValueType();
if (OpVT.isScalarInteger()) {
MVT VT = Op.getSimpleValueType();
SDValue LHS = Op.getOperand(0);
SDValue RHS = Op.getOperand(1);
ISD::CondCode CCVal = cast<CondCodeSDNode>(Op.getOperand(2))->get();
assert((CCVal == ISD::SETGT || CCVal == ISD::SETUGT) &&
"Unexpected CondCode");
SDLoc DL(Op);
// If the RHS is a constant in the range [-2049, 0) or (0, 2046], we can
// convert this to the equivalent of (set(u)ge X, C+1) by using
// (xori (slti(u) X, C+1), 1). This avoids materializing a small constant
// in a register.
if (isa<ConstantSDNode>(RHS)) {
int64_t Imm = cast<ConstantSDNode>(RHS)->getSExtValue();
if (Imm != 0 && isInt<12>((uint64_t)Imm + 1)) {
// X > -1 should have been replaced with false.
assert((CCVal != ISD::SETUGT || Imm != -1) &&
"Missing canonicalization");
// Using getSetCCSwappedOperands will convert SET(U)GT->SET(U)LT.
CCVal = ISD::getSetCCSwappedOperands(CCVal);
SDValue SetCC = DAG.getSetCC(
DL, VT, LHS, DAG.getConstant(Imm + 1, DL, OpVT), CCVal);
return DAG.getLogicalNOT(DL, SetCC, VT);
}
}
// Not a constant we could handle, swap the operands and condition code to
// SETLT/SETULT.
CCVal = ISD::getSetCCSwappedOperands(CCVal);
return DAG.getSetCC(DL, VT, RHS, LHS, CCVal);
}
return lowerFixedLengthVectorSetccToRVV(Op, DAG);
}
case ISD::ADD:
return lowerToScalableOp(Op, DAG, RISCVISD::ADD_VL, /*HasMergeOp*/ true);
case ISD::SUB:
return lowerToScalableOp(Op, DAG, RISCVISD::SUB_VL, /*HasMergeOp*/ true);
case ISD::MUL:
return lowerToScalableOp(Op, DAG, RISCVISD::MUL_VL, /*HasMergeOp*/ true);
case ISD::MULHS:
return lowerToScalableOp(Op, DAG, RISCVISD::MULHS_VL, /*HasMergeOp*/ true);
case ISD::MULHU:
return lowerToScalableOp(Op, DAG, RISCVISD::MULHU_VL, /*HasMergeOp*/ true);
case ISD::AND:
return lowerFixedLengthVectorLogicOpToRVV(Op, DAG, RISCVISD::VMAND_VL,
RISCVISD::AND_VL);
case ISD::OR:
return lowerFixedLengthVectorLogicOpToRVV(Op, DAG, RISCVISD::VMOR_VL,
RISCVISD::OR_VL);
case ISD::XOR:
return lowerFixedLengthVectorLogicOpToRVV(Op, DAG, RISCVISD::VMXOR_VL,
RISCVISD::XOR_VL);
case ISD::SDIV:
return lowerToScalableOp(Op, DAG, RISCVISD::SDIV_VL, /*HasMergeOp*/ true);
case ISD::SREM:
return lowerToScalableOp(Op, DAG, RISCVISD::SREM_VL, /*HasMergeOp*/ true);
case ISD::UDIV:
return lowerToScalableOp(Op, DAG, RISCVISD::UDIV_VL, /*HasMergeOp*/ true);
case ISD::UREM:
return lowerToScalableOp(Op, DAG, RISCVISD::UREM_VL, /*HasMergeOp*/ true);
case ISD::SHL:
case ISD::SRA:
case ISD::SRL:
if (Op.getSimpleValueType().isFixedLengthVector())
return lowerFixedLengthVectorShiftToRVV(Op, DAG);
// This can be called for an i32 shift amount that needs to be promoted.
assert(Op.getOperand(1).getValueType() == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
return SDValue();
case ISD::SADDSAT:
return lowerToScalableOp(Op, DAG, RISCVISD::SADDSAT_VL,
/*HasMergeOp*/ true);
case ISD::UADDSAT:
return lowerToScalableOp(Op, DAG, RISCVISD::UADDSAT_VL,
/*HasMergeOp*/ true);
case ISD::SSUBSAT:
return lowerToScalableOp(Op, DAG, RISCVISD::SSUBSAT_VL,
/*HasMergeOp*/ true);
case ISD::USUBSAT:
return lowerToScalableOp(Op, DAG, RISCVISD::USUBSAT_VL,
/*HasMergeOp*/ true);
case ISD::FADD:
return lowerToScalableOp(Op, DAG, RISCVISD::FADD_VL, /*HasMergeOp*/ true);
case ISD::FSUB:
return lowerToScalableOp(Op, DAG, RISCVISD::FSUB_VL, /*HasMergeOp*/ true);
case ISD::FMUL:
return lowerToScalableOp(Op, DAG, RISCVISD::FMUL_VL, /*HasMergeOp*/ true);
case ISD::FDIV:
return lowerToScalableOp(Op, DAG, RISCVISD::FDIV_VL, /*HasMergeOp*/ true);
case ISD::FNEG:
return lowerToScalableOp(Op, DAG, RISCVISD::FNEG_VL);
case ISD::FABS:
return lowerToScalableOp(Op, DAG, RISCVISD::FABS_VL);
case ISD::FSQRT:
return lowerToScalableOp(Op, DAG, RISCVISD::FSQRT_VL);
case ISD::FMA:
return lowerToScalableOp(Op, DAG, RISCVISD::VFMADD_VL);
case ISD::SMIN:
return lowerToScalableOp(Op, DAG, RISCVISD::SMIN_VL, /*HasMergeOp*/ true);
case ISD::SMAX:
return lowerToScalableOp(Op, DAG, RISCVISD::SMAX_VL, /*HasMergeOp*/ true);
case ISD::UMIN:
return lowerToScalableOp(Op, DAG, RISCVISD::UMIN_VL, /*HasMergeOp*/ true);
case ISD::UMAX:
return lowerToScalableOp(Op, DAG, RISCVISD::UMAX_VL, /*HasMergeOp*/ true);
case ISD::FMINNUM:
return lowerToScalableOp(Op, DAG, RISCVISD::FMINNUM_VL,
/*HasMergeOp*/ true);
case ISD::FMAXNUM:
return lowerToScalableOp(Op, DAG, RISCVISD::FMAXNUM_VL,
/*HasMergeOp*/ true);
case ISD::ABS:
case ISD::VP_ABS:
return lowerABS(Op, DAG);
case ISD::CTLZ:
case ISD::CTLZ_ZERO_UNDEF:
case ISD::CTTZ_ZERO_UNDEF:
return lowerCTLZ_CTTZ_ZERO_UNDEF(Op, DAG);
case ISD::VSELECT:
return lowerFixedLengthVectorSelectToRVV(Op, DAG);
case ISD::FCOPYSIGN:
return lowerFixedLengthVectorFCOPYSIGNToRVV(Op, DAG);
case ISD::STRICT_FADD:
return lowerToScalableOp(Op, DAG, RISCVISD::STRICT_FADD_VL,
/*HasMergeOp*/ true);
case ISD::STRICT_FSUB:
return lowerToScalableOp(Op, DAG, RISCVISD::STRICT_FSUB_VL,
/*HasMergeOp*/ true);
case ISD::STRICT_FMUL:
return lowerToScalableOp(Op, DAG, RISCVISD::STRICT_FMUL_VL,
/*HasMergeOp*/ true);
case ISD::STRICT_FDIV:
return lowerToScalableOp(Op, DAG, RISCVISD::STRICT_FDIV_VL,
/*HasMergeOp*/ true);
case ISD::STRICT_FSQRT:
return lowerToScalableOp(Op, DAG, RISCVISD::STRICT_FSQRT_VL);
case ISD::STRICT_FMA:
return lowerToScalableOp(Op, DAG, RISCVISD::STRICT_VFMADD_VL);
case ISD::STRICT_FSETCC:
case ISD::STRICT_FSETCCS:
return lowerVectorStrictFSetcc(Op, DAG);
case ISD::MGATHER:
case ISD::VP_GATHER:
return lowerMaskedGather(Op, DAG);
case ISD::MSCATTER:
case ISD::VP_SCATTER:
return lowerMaskedScatter(Op, DAG);
case ISD::GET_ROUNDING:
return lowerGET_ROUNDING(Op, DAG);
case ISD::SET_ROUNDING:
return lowerSET_ROUNDING(Op, DAG);
case ISD::EH_DWARF_CFA:
return lowerEH_DWARF_CFA(Op, DAG);
case ISD::VP_SELECT:
return lowerVPOp(Op, DAG, RISCVISD::VSELECT_VL);
case ISD::VP_MERGE:
return lowerVPOp(Op, DAG, RISCVISD::VP_MERGE_VL);
case ISD::VP_ADD:
return lowerVPOp(Op, DAG, RISCVISD::ADD_VL, /*HasMergeOp*/ true);
case ISD::VP_SUB:
return lowerVPOp(Op, DAG, RISCVISD::SUB_VL, /*HasMergeOp*/ true);
case ISD::VP_MUL:
return lowerVPOp(Op, DAG, RISCVISD::MUL_VL, /*HasMergeOp*/ true);
case ISD::VP_SDIV:
return lowerVPOp(Op, DAG, RISCVISD::SDIV_VL, /*HasMergeOp*/ true);
case ISD::VP_UDIV:
return lowerVPOp(Op, DAG, RISCVISD::UDIV_VL, /*HasMergeOp*/ true);
case ISD::VP_SREM:
return lowerVPOp(Op, DAG, RISCVISD::SREM_VL, /*HasMergeOp*/ true);
case ISD::VP_UREM:
return lowerVPOp(Op, DAG, RISCVISD::UREM_VL, /*HasMergeOp*/ true);
case ISD::VP_AND:
return lowerLogicVPOp(Op, DAG, RISCVISD::VMAND_VL, RISCVISD::AND_VL);
case ISD::VP_OR:
return lowerLogicVPOp(Op, DAG, RISCVISD::VMOR_VL, RISCVISD::OR_VL);
case ISD::VP_XOR:
return lowerLogicVPOp(Op, DAG, RISCVISD::VMXOR_VL, RISCVISD::XOR_VL);
case ISD::VP_ASHR:
return lowerVPOp(Op, DAG, RISCVISD::SRA_VL, /*HasMergeOp*/ true);
case ISD::VP_LSHR:
return lowerVPOp(Op, DAG, RISCVISD::SRL_VL, /*HasMergeOp*/ true);
case ISD::VP_SHL:
return lowerVPOp(Op, DAG, RISCVISD::SHL_VL, /*HasMergeOp*/ true);
case ISD::VP_FADD:
return lowerVPOp(Op, DAG, RISCVISD::FADD_VL, /*HasMergeOp*/ true);
case ISD::VP_FSUB:
return lowerVPOp(Op, DAG, RISCVISD::FSUB_VL, /*HasMergeOp*/ true);
case ISD::VP_FMUL:
return lowerVPOp(Op, DAG, RISCVISD::FMUL_VL, /*HasMergeOp*/ true);
case ISD::VP_FDIV:
return lowerVPOp(Op, DAG, RISCVISD::FDIV_VL, /*HasMergeOp*/ true);
case ISD::VP_FNEG:
return lowerVPOp(Op, DAG, RISCVISD::FNEG_VL);
case ISD::VP_FABS:
return lowerVPOp(Op, DAG, RISCVISD::FABS_VL);
case ISD::VP_SQRT:
return lowerVPOp(Op, DAG, RISCVISD::FSQRT_VL);
case ISD::VP_FMA:
return lowerVPOp(Op, DAG, RISCVISD::VFMADD_VL);
case ISD::VP_FMINNUM:
return lowerVPOp(Op, DAG, RISCVISD::FMINNUM_VL, /*HasMergeOp*/ true);
case ISD::VP_FMAXNUM:
return lowerVPOp(Op, DAG, RISCVISD::FMAXNUM_VL, /*HasMergeOp*/ true);
case ISD::VP_FCOPYSIGN:
return lowerVPOp(Op, DAG, RISCVISD::FCOPYSIGN_VL, /*HasMergeOp*/ true);
case ISD::VP_SIGN_EXTEND:
case ISD::VP_ZERO_EXTEND:
if (Op.getOperand(0).getSimpleValueType().getVectorElementType() == MVT::i1)
return lowerVPExtMaskOp(Op, DAG);
return lowerVPOp(Op, DAG,
Op.getOpcode() == ISD::VP_SIGN_EXTEND
? RISCVISD::VSEXT_VL
: RISCVISD::VZEXT_VL);
case ISD::VP_TRUNCATE:
return lowerVectorTruncLike(Op, DAG);
case ISD::VP_FP_EXTEND:
case ISD::VP_FP_ROUND:
return lowerVectorFPExtendOrRoundLike(Op, DAG);
case ISD::VP_FP_TO_SINT:
return lowerVPFPIntConvOp(Op, DAG, RISCVISD::VFCVT_RTZ_X_F_VL);
case ISD::VP_FP_TO_UINT:
return lowerVPFPIntConvOp(Op, DAG, RISCVISD::VFCVT_RTZ_XU_F_VL);
case ISD::VP_SINT_TO_FP:
return lowerVPFPIntConvOp(Op, DAG, RISCVISD::SINT_TO_FP_VL);
case ISD::VP_UINT_TO_FP:
return lowerVPFPIntConvOp(Op, DAG, RISCVISD::UINT_TO_FP_VL);
case ISD::VP_SETCC:
if (Op.getOperand(0).getSimpleValueType().getVectorElementType() == MVT::i1)
return lowerVPSetCCMaskOp(Op, DAG);
return lowerVPOp(Op, DAG, RISCVISD::SETCC_VL, /*HasMergeOp*/ true);
case ISD::VP_SMIN:
return lowerVPOp(Op, DAG, RISCVISD::SMIN_VL, /*HasMergeOp*/ true);
case ISD::VP_SMAX:
return lowerVPOp(Op, DAG, RISCVISD::SMAX_VL, /*HasMergeOp*/ true);
case ISD::VP_UMIN:
return lowerVPOp(Op, DAG, RISCVISD::UMIN_VL, /*HasMergeOp*/ true);
case ISD::VP_UMAX:
return lowerVPOp(Op, DAG, RISCVISD::UMAX_VL, /*HasMergeOp*/ true);
case ISD::EXPERIMENTAL_VP_STRIDED_LOAD:
return lowerVPStridedLoad(Op, DAG);
case ISD::EXPERIMENTAL_VP_STRIDED_STORE:
return lowerVPStridedStore(Op, DAG);
case ISD::VP_FCEIL:
case ISD::VP_FFLOOR:
case ISD::VP_FRINT:
case ISD::VP_FNEARBYINT:
case ISD::VP_FROUND:
case ISD::VP_FROUNDEVEN:
case ISD::VP_FROUNDTOZERO:
return lowerVectorFTRUNC_FCEIL_FFLOOR_FROUND(Op, DAG, Subtarget);
}
}
static SDValue getTargetNode(GlobalAddressSDNode *N, SDLoc DL, EVT Ty,
SelectionDAG &DAG, unsigned Flags) {
return DAG.getTargetGlobalAddress(N->getGlobal(), DL, Ty, 0, Flags);
}
static SDValue getTargetNode(BlockAddressSDNode *N, SDLoc DL, EVT Ty,
SelectionDAG &DAG, unsigned Flags) {
return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, N->getOffset(),
Flags);
}
static SDValue getTargetNode(ConstantPoolSDNode *N, SDLoc DL, EVT Ty,
SelectionDAG &DAG, unsigned Flags) {
return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
N->getOffset(), Flags);
}
static SDValue getTargetNode(JumpTableSDNode *N, SDLoc DL, EVT Ty,
SelectionDAG &DAG, unsigned Flags) {
return DAG.getTargetJumpTable(N->getIndex(), Ty, Flags);
}
template <class NodeTy>
SDValue RISCVTargetLowering::getAddr(NodeTy *N, SelectionDAG &DAG,
bool IsLocal) const {
SDLoc DL(N);
EVT Ty = getPointerTy(DAG.getDataLayout());
// When HWASAN is used and tagging of global variables is enabled
// they should be accessed via the GOT, since the tagged address of a global
// is incompatible with existing code models. This also applies to non-pic
// mode.
if (isPositionIndependent() || Subtarget.allowTaggedGlobals()) {
SDValue Addr = getTargetNode(N, DL, Ty, DAG, 0);
if (IsLocal && !Subtarget.allowTaggedGlobals())
// Use PC-relative addressing to access the symbol. This generates the
// pattern (PseudoLLA sym), which expands to (addi (auipc %pcrel_hi(sym))
// %pcrel_lo(auipc)).
return DAG.getNode(RISCVISD::LLA, DL, Ty, Addr);
// Use PC-relative addressing to access the GOT for this symbol, then load
// the address from the GOT. This generates the pattern (PseudoLA sym),
// which expands to (ld (addi (auipc %got_pcrel_hi(sym)) %pcrel_lo(auipc))).
MachineFunction &MF = DAG.getMachineFunction();
MachineMemOperand *MemOp = MF.getMachineMemOperand(
MachinePointerInfo::getGOT(MF),
MachineMemOperand::MOLoad | MachineMemOperand::MODereferenceable |
MachineMemOperand::MOInvariant,
LLT(Ty.getSimpleVT()), Align(Ty.getFixedSizeInBits() / 8));
SDValue Load =
DAG.getMemIntrinsicNode(RISCVISD::LA, DL, DAG.getVTList(Ty, MVT::Other),
{DAG.getEntryNode(), Addr}, Ty, MemOp);
return Load;
}
switch (getTargetMachine().getCodeModel()) {
default:
report_fatal_error("Unsupported code model for lowering");
case CodeModel::Small: {
// Generate a sequence for accessing addresses within the first 2 GiB of
// address space. This generates the pattern (addi (lui %hi(sym)) %lo(sym)).
SDValue AddrHi = getTargetNode(N, DL, Ty, DAG, RISCVII::MO_HI);
SDValue AddrLo = getTargetNode(N, DL, Ty, DAG, RISCVII::MO_LO);
SDValue MNHi = DAG.getNode(RISCVISD::HI, DL, Ty, AddrHi);
return DAG.getNode(RISCVISD::ADD_LO, DL, Ty, MNHi, AddrLo);
}
case CodeModel::Medium: {
// Generate a sequence for accessing addresses within any 2GiB range within
// the address space. This generates the pattern (PseudoLLA sym), which
// expands to (addi (auipc %pcrel_hi(sym)) %pcrel_lo(auipc)).
SDValue Addr = getTargetNode(N, DL, Ty, DAG, 0);
return DAG.getNode(RISCVISD::LLA, DL, Ty, Addr);
}
}
}
SDValue RISCVTargetLowering::lowerGlobalAddress(SDValue Op,
SelectionDAG &DAG) const {
GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
assert(N->getOffset() == 0 && "unexpected offset in global node");
return getAddr(N, DAG, N->getGlobal()->isDSOLocal());
}
SDValue RISCVTargetLowering::lowerBlockAddress(SDValue Op,
SelectionDAG &DAG) const {
BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
return getAddr(N, DAG);
}
SDValue RISCVTargetLowering::lowerConstantPool(SDValue Op,
SelectionDAG &DAG) const {
ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
return getAddr(N, DAG);
}
SDValue RISCVTargetLowering::lowerJumpTable(SDValue Op,
SelectionDAG &DAG) const {
JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
return getAddr(N, DAG);
}
SDValue RISCVTargetLowering::getStaticTLSAddr(GlobalAddressSDNode *N,
SelectionDAG &DAG,
bool UseGOT) const {
SDLoc DL(N);
EVT Ty = getPointerTy(DAG.getDataLayout());
const GlobalValue *GV = N->getGlobal();
MVT XLenVT = Subtarget.getXLenVT();
if (UseGOT) {
// Use PC-relative addressing to access the GOT for this TLS symbol, then
// load the address from the GOT and add the thread pointer. This generates
// the pattern (PseudoLA_TLS_IE sym), which expands to
// (ld (auipc %tls_ie_pcrel_hi(sym)) %pcrel_lo(auipc)).
SDValue Addr = DAG.getTargetGlobalAddress(GV, DL, Ty, 0, 0);
MachineFunction &MF = DAG.getMachineFunction();
MachineMemOperand *MemOp = MF.getMachineMemOperand(
MachinePointerInfo::getGOT(MF),
MachineMemOperand::MOLoad | MachineMemOperand::MODereferenceable |
MachineMemOperand::MOInvariant,
LLT(Ty.getSimpleVT()), Align(Ty.getFixedSizeInBits() / 8));
SDValue Load = DAG.getMemIntrinsicNode(
RISCVISD::LA_TLS_IE, DL, DAG.getVTList(Ty, MVT::Other),
{DAG.getEntryNode(), Addr}, Ty, MemOp);
// Add the thread pointer.
SDValue TPReg = DAG.getRegister(RISCV::X4, XLenVT);
return DAG.getNode(ISD::ADD, DL, Ty, Load, TPReg);
}
// Generate a sequence for accessing the address relative to the thread
// pointer, with the appropriate adjustment for the thread pointer offset.
// This generates the pattern
// (add (add_tprel (lui %tprel_hi(sym)) tp %tprel_add(sym)) %tprel_lo(sym))
SDValue AddrHi =
DAG.getTargetGlobalAddress(GV, DL, Ty, 0, RISCVII::MO_TPREL_HI);
SDValue AddrAdd =
DAG.getTargetGlobalAddress(GV, DL, Ty, 0, RISCVII::MO_TPREL_ADD);
SDValue AddrLo =
DAG.getTargetGlobalAddress(GV, DL, Ty, 0, RISCVII::MO_TPREL_LO);
SDValue MNHi = DAG.getNode(RISCVISD::HI, DL, Ty, AddrHi);
SDValue TPReg = DAG.getRegister(RISCV::X4, XLenVT);
SDValue MNAdd =
DAG.getNode(RISCVISD::ADD_TPREL, DL, Ty, MNHi, TPReg, AddrAdd);
return DAG.getNode(RISCVISD::ADD_LO, DL, Ty, MNAdd, AddrLo);
}
SDValue RISCVTargetLowering::getDynamicTLSAddr(GlobalAddressSDNode *N,
SelectionDAG &DAG) const {
SDLoc DL(N);
EVT Ty = getPointerTy(DAG.getDataLayout());
IntegerType *CallTy = Type::getIntNTy(*DAG.getContext(), Ty.getSizeInBits());
const GlobalValue *GV = N->getGlobal();
// Use a PC-relative addressing mode to access the global dynamic GOT address.
// This generates the pattern (PseudoLA_TLS_GD sym), which expands to
// (addi (auipc %tls_gd_pcrel_hi(sym)) %pcrel_lo(auipc)).
SDValue Addr = DAG.getTargetGlobalAddress(GV, DL, Ty, 0, 0);
SDValue Load = DAG.getNode(RISCVISD::LA_TLS_GD, DL, Ty, Addr);
// Prepare argument list to generate call.
ArgListTy Args;
ArgListEntry Entry;
Entry.Node = Load;
Entry.Ty = CallTy;
Args.push_back(Entry);
// Setup call to __tls_get_addr.
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(DL)
.setChain(DAG.getEntryNode())
.setLibCallee(CallingConv::C, CallTy,
DAG.getExternalSymbol("__tls_get_addr", Ty),
std::move(Args));
return LowerCallTo(CLI).first;
}
SDValue RISCVTargetLowering::lowerGlobalTLSAddress(SDValue Op,
SelectionDAG &DAG) const {
GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
assert(N->getOffset() == 0 && "unexpected offset in global node");
if (DAG.getTarget().useEmulatedTLS())
return LowerToTLSEmulatedModel(N, DAG);
TLSModel::Model Model = getTargetMachine().getTLSModel(N->getGlobal());
if (DAG.getMachineFunction().getFunction().getCallingConv() ==
CallingConv::GHC)
report_fatal_error("In GHC calling convention TLS is not supported");
SDValue Addr;
switch (Model) {
case TLSModel::LocalExec:
Addr = getStaticTLSAddr(N, DAG, /*UseGOT=*/false);
break;
case TLSModel::InitialExec:
Addr = getStaticTLSAddr(N, DAG, /*UseGOT=*/true);
break;
case TLSModel::LocalDynamic:
case TLSModel::GeneralDynamic:
Addr = getDynamicTLSAddr(N, DAG);
break;
}
return Addr;
}
SDValue RISCVTargetLowering::lowerSELECT(SDValue Op, SelectionDAG &DAG) const {
SDValue CondV = Op.getOperand(0);
SDValue TrueV = Op.getOperand(1);
SDValue FalseV = Op.getOperand(2);
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
// Lower vector SELECTs to VSELECTs by splatting the condition.
if (VT.isVector()) {
MVT SplatCondVT = VT.changeVectorElementType(MVT::i1);
SDValue CondSplat = DAG.getSplat(SplatCondVT, DL, CondV);
return DAG.getNode(ISD::VSELECT, DL, VT, CondSplat, TrueV, FalseV);
}
if (!Subtarget.hasShortForwardBranchOpt()) {
// (select c, -1, y) -> -c | y
if (isAllOnesConstant(TrueV)) {
SDValue Neg = DAG.getNegative(CondV, DL, VT);
return DAG.getNode(ISD::OR, DL, VT, Neg, FalseV);
}
// (select c, y, -1) -> (c-1) | y
if (isAllOnesConstant(FalseV)) {
SDValue Neg = DAG.getNode(ISD::ADD, DL, VT, CondV,
DAG.getAllOnesConstant(DL, VT));
return DAG.getNode(ISD::OR, DL, VT, Neg, TrueV);
}
// (select c, 0, y) -> (c-1) & y
if (isNullConstant(TrueV)) {
SDValue Neg = DAG.getNode(ISD::ADD, DL, VT, CondV,
DAG.getAllOnesConstant(DL, VT));
return DAG.getNode(ISD::AND, DL, VT, Neg, FalseV);
}
// (select c, y, 0) -> -c & y
if (isNullConstant(FalseV)) {
SDValue Neg = DAG.getNegative(CondV, DL, VT);
return DAG.getNode(ISD::AND, DL, VT, Neg, TrueV);
}
}
// If the condition is not an integer SETCC which operates on XLenVT, we need
// to emit a RISCVISD::SELECT_CC comparing the condition to zero. i.e.:
// (select condv, truev, falsev)
// -> (riscvisd::select_cc condv, zero, setne, truev, falsev)
if (CondV.getOpcode() != ISD::SETCC ||
CondV.getOperand(0).getSimpleValueType() != XLenVT) {
SDValue Zero = DAG.getConstant(0, DL, XLenVT);
SDValue SetNE = DAG.getCondCode(ISD::SETNE);
SDValue Ops[] = {CondV, Zero, SetNE, TrueV, FalseV};
return DAG.getNode(RISCVISD::SELECT_CC, DL, VT, Ops);
}
// If the CondV is the output of a SETCC node which operates on XLenVT inputs,
// then merge the SETCC node into the lowered RISCVISD::SELECT_CC to take
// advantage of the integer compare+branch instructions. i.e.:
// (select (setcc lhs, rhs, cc), truev, falsev)
// -> (riscvisd::select_cc lhs, rhs, cc, truev, falsev)
SDValue LHS = CondV.getOperand(0);
SDValue RHS = CondV.getOperand(1);
ISD::CondCode CCVal = cast<CondCodeSDNode>(CondV.getOperand(2))->get();
// Special case for a select of 2 constants that have a diffence of 1.
// Normally this is done by DAGCombine, but if the select is introduced by
// type legalization or op legalization, we miss it. Restricting to SETLT
// case for now because that is what signed saturating add/sub need.
// FIXME: We don't need the condition to be SETLT or even a SETCC,
// but we would probably want to swap the true/false values if the condition
// is SETGE/SETLE to avoid an XORI.
if (isa<ConstantSDNode>(TrueV) && isa<ConstantSDNode>(FalseV) &&
CCVal == ISD::SETLT) {
const APInt &TrueVal = cast<ConstantSDNode>(TrueV)->getAPIntValue();
const APInt &FalseVal = cast<ConstantSDNode>(FalseV)->getAPIntValue();
if (TrueVal - 1 == FalseVal)
return DAG.getNode(ISD::ADD, DL, VT, CondV, FalseV);
if (TrueVal + 1 == FalseVal)
return DAG.getNode(ISD::SUB, DL, VT, FalseV, CondV);
}
translateSetCCForBranch(DL, LHS, RHS, CCVal, DAG);
// 1 < x ? x : 1 -> 0 < x ? x : 1
if (isOneConstant(LHS) && (CCVal == ISD::SETLT || CCVal == ISD::SETULT) &&
RHS == TrueV && LHS == FalseV) {
LHS = DAG.getConstant(0, DL, VT);
// 0 <u x is the same as x != 0.
if (CCVal == ISD::SETULT) {
std::swap(LHS, RHS);
CCVal = ISD::SETNE;
}
}
// x <s -1 ? x : -1 -> x <s 0 ? x : -1
if (isAllOnesConstant(RHS) && CCVal == ISD::SETLT && LHS == TrueV &&
RHS == FalseV) {
RHS = DAG.getConstant(0, DL, VT);
}
SDValue TargetCC = DAG.getCondCode(CCVal);
if (isa<ConstantSDNode>(TrueV) && !isa<ConstantSDNode>(FalseV)) {
// (select (setcc lhs, rhs, CC), constant, falsev)
// -> (select (setcc lhs, rhs, InverseCC), falsev, constant)
std::swap(TrueV, FalseV);
TargetCC = DAG.getCondCode(ISD::getSetCCInverse(CCVal, LHS.getValueType()));
}
SDValue Ops[] = {LHS, RHS, TargetCC, TrueV, FalseV};
return DAG.getNode(RISCVISD::SELECT_CC, DL, VT, Ops);
}
SDValue RISCVTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
SDValue CondV = Op.getOperand(1);
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
if (CondV.getOpcode() == ISD::SETCC &&
CondV.getOperand(0).getValueType() == XLenVT) {
SDValue LHS = CondV.getOperand(0);
SDValue RHS = CondV.getOperand(1);
ISD::CondCode CCVal = cast<CondCodeSDNode>(CondV.getOperand(2))->get();
translateSetCCForBranch(DL, LHS, RHS, CCVal, DAG);
SDValue TargetCC = DAG.getCondCode(CCVal);
return DAG.getNode(RISCVISD::BR_CC, DL, Op.getValueType(), Op.getOperand(0),
LHS, RHS, TargetCC, Op.getOperand(2));
}
return DAG.getNode(RISCVISD::BR_CC, DL, Op.getValueType(), Op.getOperand(0),
CondV, DAG.getConstant(0, DL, XLenVT),
DAG.getCondCode(ISD::SETNE), Op.getOperand(2));
}
SDValue RISCVTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
MachineFunction &MF = DAG.getMachineFunction();
RISCVMachineFunctionInfo *FuncInfo = MF.getInfo<RISCVMachineFunctionInfo>();
SDLoc DL(Op);
SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
getPointerTy(MF.getDataLayout()));
// vastart just stores the address of the VarArgsFrameIndex slot into the
// memory location argument.
const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
MachinePointerInfo(SV));
}
SDValue RISCVTargetLowering::lowerFRAMEADDR(SDValue Op,
SelectionDAG &DAG) const {
const RISCVRegisterInfo &RI = *Subtarget.getRegisterInfo();
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo &MFI = MF.getFrameInfo();
MFI.setFrameAddressIsTaken(true);
Register FrameReg = RI.getFrameRegister(MF);
int XLenInBytes = Subtarget.getXLen() / 8;
EVT VT = Op.getValueType();
SDLoc DL(Op);
SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), DL, FrameReg, VT);
unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
while (Depth--) {
int Offset = -(XLenInBytes * 2);
SDValue Ptr = DAG.getNode(ISD::ADD, DL, VT, FrameAddr,
DAG.getIntPtrConstant(Offset, DL));
FrameAddr =
DAG.getLoad(VT, DL, DAG.getEntryNode(), Ptr, MachinePointerInfo());
}
return FrameAddr;
}
SDValue RISCVTargetLowering::lowerRETURNADDR(SDValue Op,
SelectionDAG &DAG) const {
const RISCVRegisterInfo &RI = *Subtarget.getRegisterInfo();
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo &MFI = MF.getFrameInfo();
MFI.setReturnAddressIsTaken(true);
MVT XLenVT = Subtarget.getXLenVT();
int XLenInBytes = Subtarget.getXLen() / 8;
if (verifyReturnAddressArgumentIsConstant(Op, DAG))
return SDValue();
EVT VT = Op.getValueType();
SDLoc DL(Op);
unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
if (Depth) {
int Off = -XLenInBytes;
SDValue FrameAddr = lowerFRAMEADDR(Op, DAG);
SDValue Offset = DAG.getConstant(Off, DL, VT);
return DAG.getLoad(VT, DL, DAG.getEntryNode(),
DAG.getNode(ISD::ADD, DL, VT, FrameAddr, Offset),
MachinePointerInfo());
}
// Return the value of the return address register, marking it an implicit
// live-in.
Register Reg = MF.addLiveIn(RI.getRARegister(), getRegClassFor(XLenVT));
return DAG.getCopyFromReg(DAG.getEntryNode(), DL, Reg, XLenVT);
}
SDValue RISCVTargetLowering::lowerShiftLeftParts(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
SDValue Lo = Op.getOperand(0);
SDValue Hi = Op.getOperand(1);
SDValue Shamt = Op.getOperand(2);
EVT VT = Lo.getValueType();
// if Shamt-XLEN < 0: // Shamt < XLEN
// Lo = Lo << Shamt
// Hi = (Hi << Shamt) | ((Lo >>u 1) >>u (XLEN-1 ^ Shamt))
// else:
// Lo = 0
// Hi = Lo << (Shamt-XLEN)
SDValue Zero = DAG.getConstant(0, DL, VT);
SDValue One = DAG.getConstant(1, DL, VT);
SDValue MinusXLen = DAG.getConstant(-(int)Subtarget.getXLen(), DL, VT);
SDValue XLenMinus1 = DAG.getConstant(Subtarget.getXLen() - 1, DL, VT);
SDValue ShamtMinusXLen = DAG.getNode(ISD::ADD, DL, VT, Shamt, MinusXLen);
SDValue XLenMinus1Shamt = DAG.getNode(ISD::SUB, DL, VT, XLenMinus1, Shamt);
SDValue LoTrue = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo, One);
SDValue ShiftRightLo =
DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, XLenMinus1Shamt);
SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
SDValue HiTrue = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
SDValue HiFalse = DAG.getNode(ISD::SHL, DL, VT, Lo, ShamtMinusXLen);
SDValue CC = DAG.getSetCC(DL, VT, ShamtMinusXLen, Zero, ISD::SETLT);
Lo = DAG.getNode(ISD::SELECT, DL, VT, CC, LoTrue, Zero);
Hi = DAG.getNode(ISD::SELECT, DL, VT, CC, HiTrue, HiFalse);
SDValue Parts[2] = {Lo, Hi};
return DAG.getMergeValues(Parts, DL);
}
SDValue RISCVTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
bool IsSRA) const {
SDLoc DL(Op);
SDValue Lo = Op.getOperand(0);
SDValue Hi = Op.getOperand(1);
SDValue Shamt = Op.getOperand(2);
EVT VT = Lo.getValueType();
// SRA expansion:
// if Shamt-XLEN < 0: // Shamt < XLEN
// Lo = (Lo >>u Shamt) | ((Hi << 1) << (ShAmt ^ XLEN-1))
// Hi = Hi >>s Shamt
// else:
// Lo = Hi >>s (Shamt-XLEN);
// Hi = Hi >>s (XLEN-1)
//
// SRL expansion:
// if Shamt-XLEN < 0: // Shamt < XLEN
// Lo = (Lo >>u Shamt) | ((Hi << 1) << (ShAmt ^ XLEN-1))
// Hi = Hi >>u Shamt
// else:
// Lo = Hi >>u (Shamt-XLEN);
// Hi = 0;
unsigned ShiftRightOp = IsSRA ? ISD::SRA : ISD::SRL;
SDValue Zero = DAG.getConstant(0, DL, VT);
SDValue One = DAG.getConstant(1, DL, VT);
SDValue MinusXLen = DAG.getConstant(-(int)Subtarget.getXLen(), DL, VT);
SDValue XLenMinus1 = DAG.getConstant(Subtarget.getXLen() - 1, DL, VT);
SDValue ShamtMinusXLen = DAG.getNode(ISD::ADD, DL, VT, Shamt, MinusXLen);
SDValue XLenMinus1Shamt = DAG.getNode(ISD::SUB, DL, VT, XLenMinus1, Shamt);
SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
SDValue ShiftLeftHi1 = DAG.getNode(ISD::SHL, DL, VT, Hi, One);
SDValue ShiftLeftHi =
DAG.getNode(ISD::SHL, DL, VT, ShiftLeftHi1, XLenMinus1Shamt);
SDValue LoTrue = DAG.getNode(ISD::OR, DL, VT, ShiftRightLo, ShiftLeftHi);
SDValue HiTrue = DAG.getNode(ShiftRightOp, DL, VT, Hi, Shamt);
SDValue LoFalse = DAG.getNode(ShiftRightOp, DL, VT, Hi, ShamtMinusXLen);
SDValue HiFalse =
IsSRA ? DAG.getNode(ISD::SRA, DL, VT, Hi, XLenMinus1) : Zero;
SDValue CC = DAG.getSetCC(DL, VT, ShamtMinusXLen, Zero, ISD::SETLT);
Lo = DAG.getNode(ISD::SELECT, DL, VT, CC, LoTrue, LoFalse);
Hi = DAG.getNode(ISD::SELECT, DL, VT, CC, HiTrue, HiFalse);
SDValue Parts[2] = {Lo, Hi};
return DAG.getMergeValues(Parts, DL);
}
// Lower splats of i1 types to SETCC. For each mask vector type, we have a
// legal equivalently-sized i8 type, so we can use that as a go-between.
SDValue RISCVTargetLowering::lowerVectorMaskSplat(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
SDValue SplatVal = Op.getOperand(0);
// All-zeros or all-ones splats are handled specially.
if (ISD::isConstantSplatVectorAllOnes(Op.getNode())) {
SDValue VL = getDefaultScalableVLOps(VT, DL, DAG, Subtarget).second;
return DAG.getNode(RISCVISD::VMSET_VL, DL, VT, VL);
}
if (ISD::isConstantSplatVectorAllZeros(Op.getNode())) {
SDValue VL = getDefaultScalableVLOps(VT, DL, DAG, Subtarget).second;
return DAG.getNode(RISCVISD::VMCLR_VL, DL, VT, VL);
}
MVT XLenVT = Subtarget.getXLenVT();
assert(SplatVal.getValueType() == XLenVT &&
"Unexpected type for i1 splat value");
MVT InterVT = VT.changeVectorElementType(MVT::i8);
SplatVal = DAG.getNode(ISD::AND, DL, XLenVT, SplatVal,
DAG.getConstant(1, DL, XLenVT));
SDValue LHS = DAG.getSplatVector(InterVT, DL, SplatVal);
SDValue Zero = DAG.getConstant(0, DL, InterVT);
return DAG.getSetCC(DL, VT, LHS, Zero, ISD::SETNE);
}
// Custom-lower a SPLAT_VECTOR_PARTS where XLEN<SEW, as the SEW element type is
// illegal (currently only vXi64 RV32).
// FIXME: We could also catch non-constant sign-extended i32 values and lower
// them to VMV_V_X_VL.
SDValue RISCVTargetLowering::lowerSPLAT_VECTOR_PARTS(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VecVT = Op.getSimpleValueType();
assert(!Subtarget.is64Bit() && VecVT.getVectorElementType() == MVT::i64 &&
"Unexpected SPLAT_VECTOR_PARTS lowering");
assert(Op.getNumOperands() == 2 && "Unexpected number of operands!");
SDValue Lo = Op.getOperand(0);
SDValue Hi = Op.getOperand(1);
if (VecVT.isFixedLengthVector()) {
MVT ContainerVT = getContainerForFixedLengthVector(VecVT);
SDLoc DL(Op);
auto VL = getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget).second;
SDValue Res =
splatPartsI64WithVL(DL, ContainerVT, SDValue(), Lo, Hi, VL, DAG);
return convertFromScalableVector(VecVT, Res, DAG, Subtarget);
}
if (isa<ConstantSDNode>(Lo) && isa<ConstantSDNode>(Hi)) {
int32_t LoC = cast<ConstantSDNode>(Lo)->getSExtValue();
int32_t HiC = cast<ConstantSDNode>(Hi)->getSExtValue();
// If Hi constant is all the same sign bit as Lo, lower this as a custom
// node in order to try and match RVV vector/scalar instructions.
if ((LoC >> 31) == HiC)
return DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VecVT, DAG.getUNDEF(VecVT),
Lo, DAG.getRegister(RISCV::X0, MVT::i32));
}
// Detect cases where Hi is (SRA Lo, 31) which means Hi is Lo sign extended.
if (Hi.getOpcode() == ISD::SRA && Hi.getOperand(0) == Lo &&
isa<ConstantSDNode>(Hi.getOperand(1)) &&
Hi.getConstantOperandVal(1) == 31)
return DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VecVT, DAG.getUNDEF(VecVT), Lo,
DAG.getRegister(RISCV::X0, MVT::i32));
// Fall back to use a stack store and stride x0 vector load. Use X0 as VL.
return DAG.getNode(RISCVISD::SPLAT_VECTOR_SPLIT_I64_VL, DL, VecVT,
DAG.getUNDEF(VecVT), Lo, Hi,
DAG.getRegister(RISCV::X0, MVT::i32));
}
// Custom-lower extensions from mask vectors by using a vselect either with 1
// for zero/any-extension or -1 for sign-extension:
// (vXiN = (s|z)ext vXi1:vmask) -> (vXiN = vselect vmask, (-1 or 1), 0)
// Note that any-extension is lowered identically to zero-extension.
SDValue RISCVTargetLowering::lowerVectorMaskExt(SDValue Op, SelectionDAG &DAG,
int64_t ExtTrueVal) const {
SDLoc DL(Op);
MVT VecVT = Op.getSimpleValueType();
SDValue Src = Op.getOperand(0);
// Only custom-lower extensions from mask types
assert(Src.getValueType().isVector() &&
Src.getValueType().getVectorElementType() == MVT::i1);
if (VecVT.isScalableVector()) {
SDValue SplatZero = DAG.getConstant(0, DL, VecVT);
SDValue SplatTrueVal = DAG.getConstant(ExtTrueVal, DL, VecVT);
return DAG.getNode(ISD::VSELECT, DL, VecVT, Src, SplatTrueVal, SplatZero);
}
MVT ContainerVT = getContainerForFixedLengthVector(VecVT);
MVT I1ContainerVT =
MVT::getVectorVT(MVT::i1, ContainerVT.getVectorElementCount());
SDValue CC = convertToScalableVector(I1ContainerVT, Src, DAG, Subtarget);
SDValue VL = getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget).second;
MVT XLenVT = Subtarget.getXLenVT();
SDValue SplatZero = DAG.getConstant(0, DL, XLenVT);
SDValue SplatTrueVal = DAG.getConstant(ExtTrueVal, DL, XLenVT);
SplatZero = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), SplatZero, VL);
SplatTrueVal = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), SplatTrueVal, VL);
SDValue Select = DAG.getNode(RISCVISD::VSELECT_VL, DL, ContainerVT, CC,
SplatTrueVal, SplatZero, VL);
return convertFromScalableVector(VecVT, Select, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerFixedLengthVectorExtendToRVV(
SDValue Op, SelectionDAG &DAG, unsigned ExtendOpc) const {
MVT ExtVT = Op.getSimpleValueType();
// Only custom-lower extensions from fixed-length vector types.
if (!ExtVT.isFixedLengthVector())
return Op;
MVT VT = Op.getOperand(0).getSimpleValueType();
// Grab the canonical container type for the extended type. Infer the smaller
// type from that to ensure the same number of vector elements, as we know
// the LMUL will be sufficient to hold the smaller type.
MVT ContainerExtVT = getContainerForFixedLengthVector(ExtVT);
// Get the extended container type manually to ensure the same number of
// vector elements between source and dest.
MVT ContainerVT = MVT::getVectorVT(VT.getVectorElementType(),
ContainerExtVT.getVectorElementCount());
SDValue Op1 =
convertToScalableVector(ContainerVT, Op.getOperand(0), DAG, Subtarget);
SDLoc DL(Op);
auto [Mask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
SDValue Ext = DAG.getNode(ExtendOpc, DL, ContainerExtVT, Op1, Mask, VL);
return convertFromScalableVector(ExtVT, Ext, DAG, Subtarget);
}
// Custom-lower truncations from vectors to mask vectors by using a mask and a
// setcc operation:
// (vXi1 = trunc vXiN vec) -> (vXi1 = setcc (and vec, 1), 0, ne)
SDValue RISCVTargetLowering::lowerVectorMaskTruncLike(SDValue Op,
SelectionDAG &DAG) const {
bool IsVPTrunc = Op.getOpcode() == ISD::VP_TRUNCATE;
SDLoc DL(Op);
EVT MaskVT = Op.getValueType();
// Only expect to custom-lower truncations to mask types
assert(MaskVT.isVector() && MaskVT.getVectorElementType() == MVT::i1 &&
"Unexpected type for vector mask lowering");
SDValue Src = Op.getOperand(0);
MVT VecVT = Src.getSimpleValueType();
SDValue Mask, VL;
if (IsVPTrunc) {
Mask = Op.getOperand(1);
VL = Op.getOperand(2);
}
// If this is a fixed vector, we need to convert it to a scalable vector.
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Src = convertToScalableVector(ContainerVT, Src, DAG, Subtarget);
if (IsVPTrunc) {
MVT MaskContainerVT =
getContainerForFixedLengthVector(Mask.getSimpleValueType());
Mask = convertToScalableVector(MaskContainerVT, Mask, DAG, Subtarget);
}
}
if (!IsVPTrunc) {
std::tie(Mask, VL) =
getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget);
}
SDValue SplatOne = DAG.getConstant(1, DL, Subtarget.getXLenVT());
SDValue SplatZero = DAG.getConstant(0, DL, Subtarget.getXLenVT());
SplatOne = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), SplatOne, VL);
SplatZero = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), SplatZero, VL);
MVT MaskContainerVT = ContainerVT.changeVectorElementType(MVT::i1);
SDValue Trunc = DAG.getNode(RISCVISD::AND_VL, DL, ContainerVT, Src, SplatOne,
DAG.getUNDEF(ContainerVT), Mask, VL);
Trunc = DAG.getNode(RISCVISD::SETCC_VL, DL, MaskContainerVT,
{Trunc, SplatZero, DAG.getCondCode(ISD::SETNE),
DAG.getUNDEF(MaskContainerVT), Mask, VL});
if (MaskVT.isFixedLengthVector())
Trunc = convertFromScalableVector(MaskVT, Trunc, DAG, Subtarget);
return Trunc;
}
SDValue RISCVTargetLowering::lowerVectorTruncLike(SDValue Op,
SelectionDAG &DAG) const {
bool IsVPTrunc = Op.getOpcode() == ISD::VP_TRUNCATE;
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
// Only custom-lower vector truncates
assert(VT.isVector() && "Unexpected type for vector truncate lowering");
// Truncates to mask types are handled differently
if (VT.getVectorElementType() == MVT::i1)
return lowerVectorMaskTruncLike(Op, DAG);
// RVV only has truncates which operate from SEW*2->SEW, so lower arbitrary
// truncates as a series of "RISCVISD::TRUNCATE_VECTOR_VL" nodes which
// truncate by one power of two at a time.
MVT DstEltVT = VT.getVectorElementType();
SDValue Src = Op.getOperand(0);
MVT SrcVT = Src.getSimpleValueType();
MVT SrcEltVT = SrcVT.getVectorElementType();
assert(DstEltVT.bitsLT(SrcEltVT) && isPowerOf2_64(DstEltVT.getSizeInBits()) &&
isPowerOf2_64(SrcEltVT.getSizeInBits()) &&
"Unexpected vector truncate lowering");
MVT ContainerVT = SrcVT;
SDValue Mask, VL;
if (IsVPTrunc) {
Mask = Op.getOperand(1);
VL = Op.getOperand(2);
}
if (SrcVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(SrcVT);
Src = convertToScalableVector(ContainerVT, Src, DAG, Subtarget);
if (IsVPTrunc) {
MVT MaskVT = getMaskTypeFor(ContainerVT);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
}
SDValue Result = Src;
if (!IsVPTrunc) {
std::tie(Mask, VL) =
getDefaultVLOps(SrcVT, ContainerVT, DL, DAG, Subtarget);
}
LLVMContext &Context = *DAG.getContext();
const ElementCount Count = ContainerVT.getVectorElementCount();
do {
SrcEltVT = MVT::getIntegerVT(SrcEltVT.getSizeInBits() / 2);
EVT ResultVT = EVT::getVectorVT(Context, SrcEltVT, Count);
Result = DAG.getNode(RISCVISD::TRUNCATE_VECTOR_VL, DL, ResultVT, Result,
Mask, VL);
} while (SrcEltVT != DstEltVT);
if (SrcVT.isFixedLengthVector())
Result = convertFromScalableVector(VT, Result, DAG, Subtarget);
return Result;
}
SDValue
RISCVTargetLowering::lowerStrictFPExtendOrRoundLike(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
SDValue Chain = Op.getOperand(0);
SDValue Src = Op.getOperand(1);
MVT VT = Op.getSimpleValueType();
MVT SrcVT = Src.getSimpleValueType();
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
MVT SrcContainerVT = getContainerForFixedLengthVector(SrcVT);
ContainerVT =
SrcContainerVT.changeVectorElementType(VT.getVectorElementType());
Src = convertToScalableVector(SrcContainerVT, Src, DAG, Subtarget);
}
auto [Mask, VL] = getDefaultVLOps(SrcVT, ContainerVT, DL, DAG, Subtarget);
// RVV can only widen/truncate fp to types double/half the size as the source.
if ((VT.getVectorElementType() == MVT::f64 &&
SrcVT.getVectorElementType() == MVT::f16) ||
(VT.getVectorElementType() == MVT::f16 &&
SrcVT.getVectorElementType() == MVT::f64)) {
// For double rounding, the intermediate rounding should be round-to-odd.
unsigned InterConvOpc = Op.getOpcode() == ISD::STRICT_FP_EXTEND
? RISCVISD::STRICT_FP_EXTEND_VL
: RISCVISD::STRICT_VFNCVT_ROD_VL;
MVT InterVT = ContainerVT.changeVectorElementType(MVT::f32);
Src = DAG.getNode(InterConvOpc, DL, DAG.getVTList(InterVT, MVT::Other),
Chain, Src, Mask, VL);
Chain = Src.getValue(1);
}
unsigned ConvOpc = Op.getOpcode() == ISD::STRICT_FP_EXTEND
? RISCVISD::STRICT_FP_EXTEND_VL
: RISCVISD::STRICT_FP_ROUND_VL;
SDValue Res = DAG.getNode(ConvOpc, DL, DAG.getVTList(ContainerVT, MVT::Other),
Chain, Src, Mask, VL);
if (VT.isFixedLengthVector()) {
// StrictFP operations have two result values. Their lowered result should
// have same result count.
SDValue SubVec = convertFromScalableVector(VT, Res, DAG, Subtarget);
Res = DAG.getMergeValues({SubVec, Res.getValue(1)}, DL);
}
return Res;
}
SDValue
RISCVTargetLowering::lowerVectorFPExtendOrRoundLike(SDValue Op,
SelectionDAG &DAG) const {
bool IsVP =
Op.getOpcode() == ISD::VP_FP_ROUND || Op.getOpcode() == ISD::VP_FP_EXTEND;
bool IsExtend =
Op.getOpcode() == ISD::VP_FP_EXTEND || Op.getOpcode() == ISD::FP_EXTEND;
// RVV can only do truncate fp to types half the size as the source. We
// custom-lower f64->f16 rounds via RVV's round-to-odd float
// conversion instruction.
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
assert(VT.isVector() && "Unexpected type for vector truncate lowering");
SDValue Src = Op.getOperand(0);
MVT SrcVT = Src.getSimpleValueType();
bool IsDirectExtend = IsExtend && (VT.getVectorElementType() != MVT::f64 ||
SrcVT.getVectorElementType() != MVT::f16);
bool IsDirectTrunc = !IsExtend && (VT.getVectorElementType() != MVT::f16 ||
SrcVT.getVectorElementType() != MVT::f64);
bool IsDirectConv = IsDirectExtend || IsDirectTrunc;
// Prepare any fixed-length vector operands.
MVT ContainerVT = VT;
SDValue Mask, VL;
if (IsVP) {
Mask = Op.getOperand(1);
VL = Op.getOperand(2);
}
if (VT.isFixedLengthVector()) {
MVT SrcContainerVT = getContainerForFixedLengthVector(SrcVT);
ContainerVT =
SrcContainerVT.changeVectorElementType(VT.getVectorElementType());
Src = convertToScalableVector(SrcContainerVT, Src, DAG, Subtarget);
if (IsVP) {
MVT MaskVT = getMaskTypeFor(ContainerVT);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
}
if (!IsVP)
std::tie(Mask, VL) =
getDefaultVLOps(SrcVT, ContainerVT, DL, DAG, Subtarget);
unsigned ConvOpc = IsExtend ? RISCVISD::FP_EXTEND_VL : RISCVISD::FP_ROUND_VL;
if (IsDirectConv) {
Src = DAG.getNode(ConvOpc, DL, ContainerVT, Src, Mask, VL);
if (VT.isFixedLengthVector())
Src = convertFromScalableVector(VT, Src, DAG, Subtarget);
return Src;
}
unsigned InterConvOpc =
IsExtend ? RISCVISD::FP_EXTEND_VL : RISCVISD::VFNCVT_ROD_VL;
MVT InterVT = ContainerVT.changeVectorElementType(MVT::f32);
SDValue IntermediateConv =
DAG.getNode(InterConvOpc, DL, InterVT, Src, Mask, VL);
SDValue Result =
DAG.getNode(ConvOpc, DL, ContainerVT, IntermediateConv, Mask, VL);
if (VT.isFixedLengthVector())
return convertFromScalableVector(VT, Result, DAG, Subtarget);
return Result;
}
// Custom-legalize INSERT_VECTOR_ELT so that the value is inserted into the
// first position of a vector, and that vector is slid up to the insert index.
// By limiting the active vector length to index+1 and merging with the
// original vector (with an undisturbed tail policy for elements >= VL), we
// achieve the desired result of leaving all elements untouched except the one
// at VL-1, which is replaced with the desired value.
SDValue RISCVTargetLowering::lowerINSERT_VECTOR_ELT(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VecVT = Op.getSimpleValueType();
SDValue Vec = Op.getOperand(0);
SDValue Val = Op.getOperand(1);
SDValue Idx = Op.getOperand(2);
if (VecVT.getVectorElementType() == MVT::i1) {
// FIXME: For now we just promote to an i8 vector and insert into that,
// but this is probably not optimal.
MVT WideVT = MVT::getVectorVT(MVT::i8, VecVT.getVectorElementCount());
Vec = DAG.getNode(ISD::ZERO_EXTEND, DL, WideVT, Vec);
Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, WideVT, Vec, Val, Idx);
return DAG.getNode(ISD::TRUNCATE, DL, VecVT, Vec);
}
MVT ContainerVT = VecVT;
// If the operand is a fixed-length vector, convert to a scalable one.
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
MVT XLenVT = Subtarget.getXLenVT();
bool IsLegalInsert = Subtarget.is64Bit() || Val.getValueType() != MVT::i64;
// Even i64-element vectors on RV32 can be lowered without scalar
// legalization if the most-significant 32 bits of the value are not affected
// by the sign-extension of the lower 32 bits.
// TODO: We could also catch sign extensions of a 32-bit value.
if (!IsLegalInsert && isa<ConstantSDNode>(Val)) {
const auto *CVal = cast<ConstantSDNode>(Val);
if (isInt<32>(CVal->getSExtValue())) {
IsLegalInsert = true;
Val = DAG.getConstant(CVal->getSExtValue(), DL, MVT::i32);
}
}
auto [Mask, VL] = getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget);
SDValue ValInVec;
if (IsLegalInsert) {
unsigned Opc =
VecVT.isFloatingPoint() ? RISCVISD::VFMV_S_F_VL : RISCVISD::VMV_S_X_VL;
if (isNullConstant(Idx)) {
Vec = DAG.getNode(Opc, DL, ContainerVT, Vec, Val, VL);
if (!VecVT.isFixedLengthVector())
return Vec;
return convertFromScalableVector(VecVT, Vec, DAG, Subtarget);
}
ValInVec = lowerScalarInsert(Val, VL, ContainerVT, DL, DAG, Subtarget);
} else {
// On RV32, i64-element vectors must be specially handled to place the
// value at element 0, by using two vslide1down instructions in sequence on
// the i32 split lo/hi value. Use an equivalently-sized i32 vector for
// this.
SDValue ValLo, ValHi;
std::tie(ValLo, ValHi) = DAG.SplitScalar(Val, DL, MVT::i32, MVT::i32);
MVT I32ContainerVT =
MVT::getVectorVT(MVT::i32, ContainerVT.getVectorElementCount() * 2);
SDValue I32Mask =
getDefaultScalableVLOps(I32ContainerVT, DL, DAG, Subtarget).first;
// Limit the active VL to two.
SDValue InsertI64VL = DAG.getConstant(2, DL, XLenVT);
// If the Idx is 0 we can insert directly into the vector.
if (isNullConstant(Idx)) {
// First slide in the lo value, then the hi in above it. We use slide1down
// to avoid the register group overlap constraint of vslide1up.
ValInVec = DAG.getNode(RISCVISD::VSLIDE1DOWN_VL, DL, I32ContainerVT,
Vec, Vec, ValLo, I32Mask, InsertI64VL);
// If the source vector is undef don't pass along the tail elements from
// the previous slide1down.
SDValue Tail = Vec.isUndef() ? Vec : ValInVec;
ValInVec = DAG.getNode(RISCVISD::VSLIDE1DOWN_VL, DL, I32ContainerVT,
Tail, ValInVec, ValHi, I32Mask, InsertI64VL);
// Bitcast back to the right container type.
ValInVec = DAG.getBitcast(ContainerVT, ValInVec);
if (!VecVT.isFixedLengthVector())
return ValInVec;
return convertFromScalableVector(VecVT, ValInVec, DAG, Subtarget);
}
// First slide in the lo value, then the hi in above it. We use slide1down
// to avoid the register group overlap constraint of vslide1up.
ValInVec = DAG.getNode(RISCVISD::VSLIDE1DOWN_VL, DL, I32ContainerVT,
DAG.getUNDEF(I32ContainerVT),
DAG.getUNDEF(I32ContainerVT), ValLo,
I32Mask, InsertI64VL);
ValInVec = DAG.getNode(RISCVISD::VSLIDE1DOWN_VL, DL, I32ContainerVT,
DAG.getUNDEF(I32ContainerVT), ValInVec, ValHi,
I32Mask, InsertI64VL);
// Bitcast back to the right container type.
ValInVec = DAG.getBitcast(ContainerVT, ValInVec);
}
// Now that the value is in a vector, slide it into position.
SDValue InsertVL =
DAG.getNode(ISD::ADD, DL, XLenVT, Idx, DAG.getConstant(1, DL, XLenVT));
// Use tail agnostic policy if Idx is the last index of Vec.
unsigned Policy = RISCVII::TAIL_UNDISTURBED_MASK_UNDISTURBED;
if (VecVT.isFixedLengthVector() && isa<ConstantSDNode>(Idx) &&
cast<ConstantSDNode>(Idx)->getZExtValue() + 1 ==
VecVT.getVectorNumElements())
Policy = RISCVII::TAIL_AGNOSTIC;
SDValue Slideup = getVSlideup(DAG, Subtarget, DL, ContainerVT, Vec, ValInVec,
Idx, Mask, InsertVL, Policy);
if (!VecVT.isFixedLengthVector())
return Slideup;
return convertFromScalableVector(VecVT, Slideup, DAG, Subtarget);
}
// Custom-lower EXTRACT_VECTOR_ELT operations to slide the vector down, then
// extract the first element: (extractelt (slidedown vec, idx), 0). For integer
// types this is done using VMV_X_S to allow us to glean information about the
// sign bits of the result.
SDValue RISCVTargetLowering::lowerEXTRACT_VECTOR_ELT(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
SDValue Idx = Op.getOperand(1);
SDValue Vec = Op.getOperand(0);
EVT EltVT = Op.getValueType();
MVT VecVT = Vec.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
if (VecVT.getVectorElementType() == MVT::i1) {
// Use vfirst.m to extract the first bit.
if (isNullConstant(Idx)) {
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
auto [Mask, VL] = getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget);
SDValue Vfirst =
DAG.getNode(RISCVISD::VFIRST_VL, DL, XLenVT, Vec, Mask, VL);
return DAG.getSetCC(DL, XLenVT, Vfirst, DAG.getConstant(0, DL, XLenVT),
ISD::SETEQ);
}
if (VecVT.isFixedLengthVector()) {
unsigned NumElts = VecVT.getVectorNumElements();
if (NumElts >= 8) {
MVT WideEltVT;
unsigned WidenVecLen;
SDValue ExtractElementIdx;
SDValue ExtractBitIdx;
unsigned MaxEEW = Subtarget.getELEN();
MVT LargestEltVT = MVT::getIntegerVT(
std::min(MaxEEW, unsigned(XLenVT.getSizeInBits())));
if (NumElts <= LargestEltVT.getSizeInBits()) {
assert(isPowerOf2_32(NumElts) &&
"the number of elements should be power of 2");
WideEltVT = MVT::getIntegerVT(NumElts);
WidenVecLen = 1;
ExtractElementIdx = DAG.getConstant(0, DL, XLenVT);
ExtractBitIdx = Idx;
} else {
WideEltVT = LargestEltVT;
WidenVecLen = NumElts / WideEltVT.getSizeInBits();
// extract element index = index / element width
ExtractElementIdx = DAG.getNode(
ISD::SRL, DL, XLenVT, Idx,
DAG.getConstant(Log2_64(WideEltVT.getSizeInBits()), DL, XLenVT));
// mask bit index = index % element width
ExtractBitIdx = DAG.getNode(
ISD::AND, DL, XLenVT, Idx,
DAG.getConstant(WideEltVT.getSizeInBits() - 1, DL, XLenVT));
}
MVT WideVT = MVT::getVectorVT(WideEltVT, WidenVecLen);
Vec = DAG.getNode(ISD::BITCAST, DL, WideVT, Vec);
SDValue ExtractElt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, XLenVT,
Vec, ExtractElementIdx);
// Extract the bit from GPR.
SDValue ShiftRight =
DAG.getNode(ISD::SRL, DL, XLenVT, ExtractElt, ExtractBitIdx);
return DAG.getNode(ISD::AND, DL, XLenVT, ShiftRight,
DAG.getConstant(1, DL, XLenVT));
}
}
// Otherwise, promote to an i8 vector and extract from that.
MVT WideVT = MVT::getVectorVT(MVT::i8, VecVT.getVectorElementCount());
Vec = DAG.getNode(ISD::ZERO_EXTEND, DL, WideVT, Vec);
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, EltVT, Vec, Idx);
}
// If this is a fixed vector, we need to convert it to a scalable vector.
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
// If the index is 0, the vector is already in the right position.
if (!isNullConstant(Idx)) {
// Use a VL of 1 to avoid processing more elements than we need.
auto [Mask, VL] = getDefaultVLOps(1, ContainerVT, DL, DAG, Subtarget);
Vec = getVSlidedown(DAG, Subtarget, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), Vec, Idx, Mask, VL);
}
if (!EltVT.isInteger()) {
// Floating-point extracts are handled in TableGen.
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, EltVT, Vec,
DAG.getConstant(0, DL, XLenVT));
}
SDValue Elt0 = DAG.getNode(RISCVISD::VMV_X_S, DL, XLenVT, Vec);
return DAG.getNode(ISD::TRUNCATE, DL, EltVT, Elt0);
}
// Some RVV intrinsics may claim that they want an integer operand to be
// promoted or expanded.
static SDValue lowerVectorIntrinsicScalars(SDValue Op, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
assert((Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_W_CHAIN) &&
"Unexpected opcode");
if (!Subtarget.hasVInstructions())
return SDValue();
bool HasChain = Op.getOpcode() == ISD::INTRINSIC_W_CHAIN;
unsigned IntNo = Op.getConstantOperandVal(HasChain ? 1 : 0);
SDLoc DL(Op);
const RISCVVIntrinsicsTable::RISCVVIntrinsicInfo *II =
RISCVVIntrinsicsTable::getRISCVVIntrinsicInfo(IntNo);
if (!II || !II->hasScalarOperand())
return SDValue();
unsigned SplatOp = II->ScalarOperand + 1 + HasChain;
assert(SplatOp < Op.getNumOperands());
SmallVector<SDValue, 8> Operands(Op->op_begin(), Op->op_end());
SDValue &ScalarOp = Operands[SplatOp];
MVT OpVT = ScalarOp.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
// If this isn't a scalar, or its type is XLenVT we're done.
if (!OpVT.isScalarInteger() || OpVT == XLenVT)
return SDValue();
// Simplest case is that the operand needs to be promoted to XLenVT.
if (OpVT.bitsLT(XLenVT)) {
// If the operand is a constant, sign extend to increase our chances
// of being able to use a .vi instruction. ANY_EXTEND would become a
// a zero extend and the simm5 check in isel would fail.
// FIXME: Should we ignore the upper bits in isel instead?
unsigned ExtOpc =
isa<ConstantSDNode>(ScalarOp) ? ISD::SIGN_EXTEND : ISD::ANY_EXTEND;
ScalarOp = DAG.getNode(ExtOpc, DL, XLenVT, ScalarOp);
return DAG.getNode(Op->getOpcode(), DL, Op->getVTList(), Operands);
}
// Use the previous operand to get the vXi64 VT. The result might be a mask
// VT for compares. Using the previous operand assumes that the previous
// operand will never have a smaller element size than a scalar operand and
// that a widening operation never uses SEW=64.
// NOTE: If this fails the below assert, we can probably just find the
// element count from any operand or result and use it to construct the VT.
assert(II->ScalarOperand > 0 && "Unexpected splat operand!");
MVT VT = Op.getOperand(SplatOp - 1).getSimpleValueType();
// The more complex case is when the scalar is larger than XLenVT.
assert(XLenVT == MVT::i32 && OpVT == MVT::i64 &&
VT.getVectorElementType() == MVT::i64 && "Unexpected VTs!");
// If this is a sign-extended 32-bit value, we can truncate it and rely on the
// instruction to sign-extend since SEW>XLEN.
if (DAG.ComputeNumSignBits(ScalarOp) > 32) {
ScalarOp = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, ScalarOp);
return DAG.getNode(Op->getOpcode(), DL, Op->getVTList(), Operands);
}
switch (IntNo) {
case Intrinsic::riscv_vslide1up:
case Intrinsic::riscv_vslide1down:
case Intrinsic::riscv_vslide1up_mask:
case Intrinsic::riscv_vslide1down_mask: {
// We need to special case these when the scalar is larger than XLen.
unsigned NumOps = Op.getNumOperands();
bool IsMasked = NumOps == 7;
// Convert the vector source to the equivalent nxvXi32 vector.
MVT I32VT = MVT::getVectorVT(MVT::i32, VT.getVectorElementCount() * 2);
SDValue Vec = DAG.getBitcast(I32VT, Operands[2]);
SDValue ScalarLo, ScalarHi;
std::tie(ScalarLo, ScalarHi) =
DAG.SplitScalar(ScalarOp, DL, MVT::i32, MVT::i32);
// Double the VL since we halved SEW.
SDValue AVL = getVLOperand(Op);
SDValue I32VL;
// Optimize for constant AVL
if (isa<ConstantSDNode>(AVL)) {
unsigned EltSize = VT.getScalarSizeInBits();
unsigned MinSize = VT.getSizeInBits().getKnownMinValue();
unsigned VectorBitsMax = Subtarget.getRealMaxVLen();
unsigned MaxVLMAX =
RISCVTargetLowering::computeVLMAX(VectorBitsMax, EltSize, MinSize);
unsigned VectorBitsMin = Subtarget.getRealMinVLen();
unsigned MinVLMAX =
RISCVTargetLowering::computeVLMAX(VectorBitsMin, EltSize, MinSize);
uint64_t AVLInt = cast<ConstantSDNode>(AVL)->getZExtValue();
if (AVLInt <= MinVLMAX) {
I32VL = DAG.getConstant(2 * AVLInt, DL, XLenVT);
} else if (AVLInt >= 2 * MaxVLMAX) {
// Just set vl to VLMAX in this situation
RISCVII::VLMUL Lmul = RISCVTargetLowering::getLMUL(I32VT);
SDValue LMUL = DAG.getConstant(Lmul, DL, XLenVT);
unsigned Sew = RISCVVType::encodeSEW(I32VT.getScalarSizeInBits());
SDValue SEW = DAG.getConstant(Sew, DL, XLenVT);
SDValue SETVLMAX = DAG.getTargetConstant(
Intrinsic::riscv_vsetvlimax, DL, MVT::i32);
I32VL = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, XLenVT, SETVLMAX, SEW,
LMUL);
} else {
// For AVL between (MinVLMAX, 2 * MaxVLMAX), the actual working vl
// is related to the hardware implementation.
// So let the following code handle
}
}
if (!I32VL) {
RISCVII::VLMUL Lmul = RISCVTargetLowering::getLMUL(VT);
SDValue LMUL = DAG.getConstant(Lmul, DL, XLenVT);
unsigned Sew = RISCVVType::encodeSEW(VT.getScalarSizeInBits());
SDValue SEW = DAG.getConstant(Sew, DL, XLenVT);
SDValue SETVL =
DAG.getTargetConstant(Intrinsic::riscv_vsetvli, DL, MVT::i32);
// Using vsetvli instruction to get actually used length which related to
// the hardware implementation
SDValue VL = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, XLenVT, SETVL, AVL,
SEW, LMUL);
I32VL =
DAG.getNode(ISD::SHL, DL, XLenVT, VL, DAG.getConstant(1, DL, XLenVT));
}
SDValue I32Mask = getAllOnesMask(I32VT, I32VL, DL, DAG);
// Shift the two scalar parts in using SEW=32 slide1up/slide1down
// instructions.
SDValue Passthru;
if (IsMasked)
Passthru = DAG.getUNDEF(I32VT);
else
Passthru = DAG.getBitcast(I32VT, Operands[1]);
if (IntNo == Intrinsic::riscv_vslide1up ||
IntNo == Intrinsic::riscv_vslide1up_mask) {
Vec = DAG.getNode(RISCVISD::VSLIDE1UP_VL, DL, I32VT, Passthru, Vec,
ScalarHi, I32Mask, I32VL);
Vec = DAG.getNode(RISCVISD::VSLIDE1UP_VL, DL, I32VT, Passthru, Vec,
ScalarLo, I32Mask, I32VL);
} else {
Vec = DAG.getNode(RISCVISD::VSLIDE1DOWN_VL, DL, I32VT, Passthru, Vec,
ScalarLo, I32Mask, I32VL);
Vec = DAG.getNode(RISCVISD::VSLIDE1DOWN_VL, DL, I32VT, Passthru, Vec,
ScalarHi, I32Mask, I32VL);
}
// Convert back to nxvXi64.
Vec = DAG.getBitcast(VT, Vec);
if (!IsMasked)
return Vec;
// Apply mask after the operation.
SDValue Mask = Operands[NumOps - 3];
SDValue MaskedOff = Operands[1];
// Assume Policy operand is the last operand.
uint64_t Policy =
cast<ConstantSDNode>(Operands[NumOps - 1])->getZExtValue();
// We don't need to select maskedoff if it's undef.
if (MaskedOff.isUndef())
return Vec;
// TAMU
if (Policy == RISCVII::TAIL_AGNOSTIC)
return DAG.getNode(RISCVISD::VSELECT_VL, DL, VT, Mask, Vec, MaskedOff,
AVL);
// TUMA or TUMU: Currently we always emit tumu policy regardless of tuma.
// It's fine because vmerge does not care mask policy.
return DAG.getNode(RISCVISD::VP_MERGE_VL, DL, VT, Mask, Vec, MaskedOff,
AVL);
}
}
// We need to convert the scalar to a splat vector.
SDValue VL = getVLOperand(Op);
assert(VL.getValueType() == XLenVT);
ScalarOp = splatSplitI64WithVL(DL, VT, SDValue(), ScalarOp, VL, DAG);
return DAG.getNode(Op->getOpcode(), DL, Op->getVTList(), Operands);
}
SDValue RISCVTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
SelectionDAG &DAG) const {
unsigned IntNo = Op.getConstantOperandVal(0);
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
switch (IntNo) {
default:
break; // Don't custom lower most intrinsics.
case Intrinsic::thread_pointer: {
EVT PtrVT = getPointerTy(DAG.getDataLayout());
return DAG.getRegister(RISCV::X4, PtrVT);
}
case Intrinsic::riscv_orc_b:
case Intrinsic::riscv_brev8: {
unsigned Opc =
IntNo == Intrinsic::riscv_brev8 ? RISCVISD::BREV8 : RISCVISD::ORC_B;
return DAG.getNode(Opc, DL, XLenVT, Op.getOperand(1));
}
case Intrinsic::riscv_zip:
case Intrinsic::riscv_unzip: {
unsigned Opc =
IntNo == Intrinsic::riscv_zip ? RISCVISD::ZIP : RISCVISD::UNZIP;
return DAG.getNode(Opc, DL, XLenVT, Op.getOperand(1));
}
case Intrinsic::riscv_vmv_x_s:
assert(Op.getValueType() == XLenVT && "Unexpected VT!");
return DAG.getNode(RISCVISD::VMV_X_S, DL, Op.getValueType(),
Op.getOperand(1));
case Intrinsic::riscv_vfmv_f_s:
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, Op.getValueType(),
Op.getOperand(1), DAG.getConstant(0, DL, XLenVT));
case Intrinsic::riscv_vmv_v_x:
return lowerScalarSplat(Op.getOperand(1), Op.getOperand(2),
Op.getOperand(3), Op.getSimpleValueType(), DL, DAG,
Subtarget);
case Intrinsic::riscv_vfmv_v_f:
return DAG.getNode(RISCVISD::VFMV_V_F_VL, DL, Op.getValueType(),
Op.getOperand(1), Op.getOperand(2), Op.getOperand(3));
case Intrinsic::riscv_vmv_s_x: {
SDValue Scalar = Op.getOperand(2);
if (Scalar.getValueType().bitsLE(XLenVT)) {
Scalar = DAG.getNode(ISD::ANY_EXTEND, DL, XLenVT, Scalar);
return DAG.getNode(RISCVISD::VMV_S_X_VL, DL, Op.getValueType(),
Op.getOperand(1), Scalar, Op.getOperand(3));
}
assert(Scalar.getValueType() == MVT::i64 && "Unexpected scalar VT!");
// This is an i64 value that lives in two scalar registers. We have to
// insert this in a convoluted way. First we build vXi64 splat containing
// the two values that we assemble using some bit math. Next we'll use
// vid.v and vmseq to build a mask with bit 0 set. Then we'll use that mask
// to merge element 0 from our splat into the source vector.
// FIXME: This is probably not the best way to do this, but it is
// consistent with INSERT_VECTOR_ELT lowering so it is a good starting
// point.
// sw lo, (a0)
// sw hi, 4(a0)
// vlse vX, (a0)
//
// vid.v vVid
// vmseq.vx mMask, vVid, 0
// vmerge.vvm vDest, vSrc, vVal, mMask
MVT VT = Op.getSimpleValueType();
SDValue Vec = Op.getOperand(1);
SDValue VL = getVLOperand(Op);
SDValue SplattedVal = splatSplitI64WithVL(DL, VT, SDValue(), Scalar, VL, DAG);
if (Op.getOperand(1).isUndef())
return SplattedVal;
SDValue SplattedIdx =
DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VT, DAG.getUNDEF(VT),
DAG.getConstant(0, DL, MVT::i32), VL);
MVT MaskVT = getMaskTypeFor(VT);
SDValue Mask = getAllOnesMask(VT, VL, DL, DAG);
SDValue VID = DAG.getNode(RISCVISD::VID_VL, DL, VT, Mask, VL);
SDValue SelectCond =
DAG.getNode(RISCVISD::SETCC_VL, DL, MaskVT,
{VID, SplattedIdx, DAG.getCondCode(ISD::SETEQ),
DAG.getUNDEF(MaskVT), Mask, VL});
return DAG.getNode(RISCVISD::VSELECT_VL, DL, VT, SelectCond, SplattedVal,
Vec, VL);
}
}
return lowerVectorIntrinsicScalars(Op, DAG, Subtarget);
}
SDValue RISCVTargetLowering::LowerINTRINSIC_W_CHAIN(SDValue Op,
SelectionDAG &DAG) const {
unsigned IntNo = Op.getConstantOperandVal(1);
switch (IntNo) {
default:
break;
case Intrinsic::riscv_masked_strided_load: {
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
// If the mask is known to be all ones, optimize to an unmasked intrinsic;
// the selection of the masked intrinsics doesn't do this for us.
SDValue Mask = Op.getOperand(5);
bool IsUnmasked = ISD::isConstantSplatVectorAllOnes(Mask.getNode());
MVT VT = Op->getSimpleValueType(0);
MVT ContainerVT = VT;
if (VT.isFixedLengthVector())
ContainerVT = getContainerForFixedLengthVector(VT);
SDValue PassThru = Op.getOperand(2);
if (!IsUnmasked) {
MVT MaskVT = getMaskTypeFor(ContainerVT);
if (VT.isFixedLengthVector()) {
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
PassThru = convertToScalableVector(ContainerVT, PassThru, DAG, Subtarget);
}
}
auto *Load = cast<MemIntrinsicSDNode>(Op);
SDValue VL = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).second;
SDValue Ptr = Op.getOperand(3);
SDValue Stride = Op.getOperand(4);
SDValue Result, Chain;
// TODO: We restrict this to unmasked loads currently in consideration of
// the complexity of hanlding all falses masks.
if (IsUnmasked && isNullConstant(Stride)) {
MVT ScalarVT = ContainerVT.getVectorElementType();
SDValue ScalarLoad =
DAG.getExtLoad(ISD::ZEXTLOAD, DL, XLenVT, Load->getChain(), Ptr,
ScalarVT, Load->getMemOperand());
Chain = ScalarLoad.getValue(1);
Result = lowerScalarSplat(SDValue(), ScalarLoad, VL, ContainerVT, DL, DAG,
Subtarget);
} else {
SDValue IntID = DAG.getTargetConstant(
IsUnmasked ? Intrinsic::riscv_vlse : Intrinsic::riscv_vlse_mask, DL,
XLenVT);
SmallVector<SDValue, 8> Ops{Load->getChain(), IntID};
if (IsUnmasked)
Ops.push_back(DAG.getUNDEF(ContainerVT));
else
Ops.push_back(PassThru);
Ops.push_back(Ptr);
Ops.push_back(Stride);
if (!IsUnmasked)
Ops.push_back(Mask);
Ops.push_back(VL);
if (!IsUnmasked) {
SDValue Policy =
DAG.getTargetConstant(RISCVII::TAIL_AGNOSTIC, DL, XLenVT);
Ops.push_back(Policy);
}
SDVTList VTs = DAG.getVTList({ContainerVT, MVT::Other});
Result =
DAG.getMemIntrinsicNode(ISD::INTRINSIC_W_CHAIN, DL, VTs, Ops,
Load->getMemoryVT(), Load->getMemOperand());
Chain = Result.getValue(1);
}
if (VT.isFixedLengthVector())
Result = convertFromScalableVector(VT, Result, DAG, Subtarget);
return DAG.getMergeValues({Result, Chain}, DL);
}
case Intrinsic::riscv_seg2_load:
case Intrinsic::riscv_seg3_load:
case Intrinsic::riscv_seg4_load:
case Intrinsic::riscv_seg5_load:
case Intrinsic::riscv_seg6_load:
case Intrinsic::riscv_seg7_load:
case Intrinsic::riscv_seg8_load: {
SDLoc DL(Op);
static const Intrinsic::ID VlsegInts[7] = {
Intrinsic::riscv_vlseg2, Intrinsic::riscv_vlseg3,
Intrinsic::riscv_vlseg4, Intrinsic::riscv_vlseg5,
Intrinsic::riscv_vlseg6, Intrinsic::riscv_vlseg7,
Intrinsic::riscv_vlseg8};
unsigned NF = Op->getNumValues() - 1;
assert(NF >= 2 && NF <= 8 && "Unexpected seg number");
MVT XLenVT = Subtarget.getXLenVT();
MVT VT = Op->getSimpleValueType(0);
MVT ContainerVT = getContainerForFixedLengthVector(VT);
SDValue VL = getVLOp(VT.getVectorNumElements(), DL, DAG, Subtarget);
SDValue IntID = DAG.getTargetConstant(VlsegInts[NF - 2], DL, XLenVT);
auto *Load = cast<MemIntrinsicSDNode>(Op);
SmallVector<EVT, 9> ContainerVTs(NF, ContainerVT);
ContainerVTs.push_back(MVT::Other);
SDVTList VTs = DAG.getVTList(ContainerVTs);
SmallVector<SDValue, 12> Ops = {Load->getChain(), IntID};
Ops.insert(Ops.end(), NF, DAG.getUNDEF(ContainerVT));
Ops.push_back(Op.getOperand(2));
Ops.push_back(VL);
SDValue Result =
DAG.getMemIntrinsicNode(ISD::INTRINSIC_W_CHAIN, DL, VTs, Ops,
Load->getMemoryVT(), Load->getMemOperand());
SmallVector<SDValue, 9> Results;
for (unsigned int RetIdx = 0; RetIdx < NF; RetIdx++)
Results.push_back(convertFromScalableVector(VT, Result.getValue(RetIdx),
DAG, Subtarget));
Results.push_back(Result.getValue(NF));
return DAG.getMergeValues(Results, DL);
}
}
return lowerVectorIntrinsicScalars(Op, DAG, Subtarget);
}
SDValue RISCVTargetLowering::LowerINTRINSIC_VOID(SDValue Op,
SelectionDAG &DAG) const {
unsigned IntNo = Op.getConstantOperandVal(1);
switch (IntNo) {
default:
break;
case Intrinsic::riscv_masked_strided_store: {
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
// If the mask is known to be all ones, optimize to an unmasked intrinsic;
// the selection of the masked intrinsics doesn't do this for us.
SDValue Mask = Op.getOperand(5);
bool IsUnmasked = ISD::isConstantSplatVectorAllOnes(Mask.getNode());
SDValue Val = Op.getOperand(2);
MVT VT = Val.getSimpleValueType();
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
Val = convertToScalableVector(ContainerVT, Val, DAG, Subtarget);
}
if (!IsUnmasked) {
MVT MaskVT = getMaskTypeFor(ContainerVT);
if (VT.isFixedLengthVector())
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
SDValue VL = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).second;
SDValue IntID = DAG.getTargetConstant(
IsUnmasked ? Intrinsic::riscv_vsse : Intrinsic::riscv_vsse_mask, DL,
XLenVT);
auto *Store = cast<MemIntrinsicSDNode>(Op);
SmallVector<SDValue, 8> Ops{Store->getChain(), IntID};
Ops.push_back(Val);
Ops.push_back(Op.getOperand(3)); // Ptr
Ops.push_back(Op.getOperand(4)); // Stride
if (!IsUnmasked)
Ops.push_back(Mask);
Ops.push_back(VL);
return DAG.getMemIntrinsicNode(ISD::INTRINSIC_VOID, DL, Store->getVTList(),
Ops, Store->getMemoryVT(),
Store->getMemOperand());
}
case Intrinsic::riscv_seg2_store:
case Intrinsic::riscv_seg3_store:
case Intrinsic::riscv_seg4_store:
case Intrinsic::riscv_seg5_store:
case Intrinsic::riscv_seg6_store:
case Intrinsic::riscv_seg7_store:
case Intrinsic::riscv_seg8_store: {
SDLoc DL(Op);
static const Intrinsic::ID VssegInts[] = {
Intrinsic::riscv_vsseg2, Intrinsic::riscv_vsseg3,
Intrinsic::riscv_vsseg4, Intrinsic::riscv_vsseg5,
Intrinsic::riscv_vsseg6, Intrinsic::riscv_vsseg7,
Intrinsic::riscv_vsseg8};
// Operands are (chain, int_id, vec*, ptr, vl)
unsigned NF = Op->getNumOperands() - 4;
assert(NF >= 2 && NF <= 8 && "Unexpected seg number");
MVT XLenVT = Subtarget.getXLenVT();
MVT VT = Op->getOperand(2).getSimpleValueType();
MVT ContainerVT = getContainerForFixedLengthVector(VT);
SDValue VL = getVLOp(VT.getVectorNumElements(), DL, DAG, Subtarget);
SDValue IntID = DAG.getTargetConstant(VssegInts[NF - 2], DL, XLenVT);
SDValue Ptr = Op->getOperand(NF + 2);
auto *FixedIntrinsic = cast<MemIntrinsicSDNode>(Op);
SmallVector<SDValue, 12> Ops = {FixedIntrinsic->getChain(), IntID};
for (unsigned i = 0; i < NF; i++)
Ops.push_back(convertToScalableVector(
ContainerVT, FixedIntrinsic->getOperand(2 + i), DAG, Subtarget));
Ops.append({Ptr, VL});
return DAG.getMemIntrinsicNode(
ISD::INTRINSIC_VOID, DL, DAG.getVTList(MVT::Other), Ops,
FixedIntrinsic->getMemoryVT(), FixedIntrinsic->getMemOperand());
}
}
return SDValue();
}
static unsigned getRVVReductionOp(unsigned ISDOpcode) {
switch (ISDOpcode) {
default:
llvm_unreachable("Unhandled reduction");
case ISD::VECREDUCE_ADD:
return RISCVISD::VECREDUCE_ADD_VL;
case ISD::VECREDUCE_UMAX:
return RISCVISD::VECREDUCE_UMAX_VL;
case ISD::VECREDUCE_SMAX:
return RISCVISD::VECREDUCE_SMAX_VL;
case ISD::VECREDUCE_UMIN:
return RISCVISD::VECREDUCE_UMIN_VL;
case ISD::VECREDUCE_SMIN:
return RISCVISD::VECREDUCE_SMIN_VL;
case ISD::VECREDUCE_AND:
return RISCVISD::VECREDUCE_AND_VL;
case ISD::VECREDUCE_OR:
return RISCVISD::VECREDUCE_OR_VL;
case ISD::VECREDUCE_XOR:
return RISCVISD::VECREDUCE_XOR_VL;
}
}
SDValue RISCVTargetLowering::lowerVectorMaskVecReduction(SDValue Op,
SelectionDAG &DAG,
bool IsVP) const {
SDLoc DL(Op);
SDValue Vec = Op.getOperand(IsVP ? 1 : 0);
MVT VecVT = Vec.getSimpleValueType();
assert((Op.getOpcode() == ISD::VECREDUCE_AND ||
Op.getOpcode() == ISD::VECREDUCE_OR ||
Op.getOpcode() == ISD::VECREDUCE_XOR ||
Op.getOpcode() == ISD::VP_REDUCE_AND ||
Op.getOpcode() == ISD::VP_REDUCE_OR ||
Op.getOpcode() == ISD::VP_REDUCE_XOR) &&
"Unexpected reduction lowering");
MVT XLenVT = Subtarget.getXLenVT();
assert(Op.getValueType() == XLenVT &&
"Expected reduction output to be legalized to XLenVT");
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
SDValue Mask, VL;
if (IsVP) {
Mask = Op.getOperand(2);
VL = Op.getOperand(3);
} else {
std::tie(Mask, VL) =
getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget);
}
unsigned BaseOpc;
ISD::CondCode CC;
SDValue Zero = DAG.getConstant(0, DL, XLenVT);
switch (Op.getOpcode()) {
default:
llvm_unreachable("Unhandled reduction");
case ISD::VECREDUCE_AND:
case ISD::VP_REDUCE_AND: {
// vcpop ~x == 0
SDValue TrueMask = DAG.getNode(RISCVISD::VMSET_VL, DL, ContainerVT, VL);
Vec = DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Vec, TrueMask, VL);
Vec = DAG.getNode(RISCVISD::VCPOP_VL, DL, XLenVT, Vec, Mask, VL);
CC = ISD::SETEQ;
BaseOpc = ISD::AND;
break;
}
case ISD::VECREDUCE_OR:
case ISD::VP_REDUCE_OR:
// vcpop x != 0
Vec = DAG.getNode(RISCVISD::VCPOP_VL, DL, XLenVT, Vec, Mask, VL);
CC = ISD::SETNE;
BaseOpc = ISD::OR;
break;
case ISD::VECREDUCE_XOR:
case ISD::VP_REDUCE_XOR: {
// ((vcpop x) & 1) != 0
SDValue One = DAG.getConstant(1, DL, XLenVT);
Vec = DAG.getNode(RISCVISD::VCPOP_VL, DL, XLenVT, Vec, Mask, VL);
Vec = DAG.getNode(ISD::AND, DL, XLenVT, Vec, One);
CC = ISD::SETNE;
BaseOpc = ISD::XOR;
break;
}
}
SDValue SetCC = DAG.getSetCC(DL, XLenVT, Vec, Zero, CC);
if (!IsVP)
return SetCC;
// Now include the start value in the operation.
// Note that we must return the start value when no elements are operated
// upon. The vcpop instructions we've emitted in each case above will return
// 0 for an inactive vector, and so we've already received the neutral value:
// AND gives us (0 == 0) -> 1 and OR/XOR give us (0 != 0) -> 0. Therefore we
// can simply include the start value.
return DAG.getNode(BaseOpc, DL, XLenVT, SetCC, Op.getOperand(0));
}
static bool hasNonZeroAVL(SDValue AVL) {
auto *RegisterAVL = dyn_cast<RegisterSDNode>(AVL);
auto *ImmAVL = dyn_cast<ConstantSDNode>(AVL);
return (RegisterAVL && RegisterAVL->getReg() == RISCV::X0) ||
(ImmAVL && ImmAVL->getZExtValue() >= 1);
}
/// Helper to lower a reduction sequence of the form:
/// scalar = reduce_op vec, scalar_start
static SDValue lowerReductionSeq(unsigned RVVOpcode, MVT ResVT,
SDValue StartValue, SDValue Vec, SDValue Mask,
SDValue VL, SDLoc DL, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
const MVT VecVT = Vec.getSimpleValueType();
const MVT M1VT = getLMUL1VT(VecVT);
const MVT XLenVT = Subtarget.getXLenVT();
const bool NonZeroAVL = hasNonZeroAVL(VL);
// The reduction needs an LMUL1 input; do the splat at either LMUL1
// or the original VT if fractional.
auto InnerVT = VecVT.bitsLE(M1VT) ? VecVT : M1VT;
// We reuse the VL of the reduction to reduce vsetvli toggles if we can
// prove it is non-zero. For the AVL=0 case, we need the scalar to
// be the result of the reduction operation.
auto InnerVL = NonZeroAVL ? VL : DAG.getConstant(1, DL, XLenVT);
SDValue InitialValue = lowerScalarInsert(StartValue, InnerVL, InnerVT, DL,
DAG, Subtarget);
if (M1VT != InnerVT)
InitialValue = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, M1VT,
DAG.getUNDEF(M1VT),
InitialValue, DAG.getConstant(0, DL, XLenVT));
SDValue PassThru = NonZeroAVL ? DAG.getUNDEF(M1VT) : InitialValue;
SDValue Policy = DAG.getTargetConstant(RISCVII::TAIL_AGNOSTIC, DL, XLenVT);
SDValue Ops[] = {PassThru, Vec, InitialValue, Mask, VL, Policy};
SDValue Reduction = DAG.getNode(RVVOpcode, DL, M1VT, Ops);
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ResVT, Reduction,
DAG.getConstant(0, DL, XLenVT));
}
SDValue RISCVTargetLowering::lowerVECREDUCE(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
SDValue Vec = Op.getOperand(0);
EVT VecEVT = Vec.getValueType();
unsigned BaseOpc = ISD::getVecReduceBaseOpcode(Op.getOpcode());
// Due to ordering in legalize types we may have a vector type that needs to
// be split. Do that manually so we can get down to a legal type.
while (getTypeAction(*DAG.getContext(), VecEVT) ==
TargetLowering::TypeSplitVector) {
auto [Lo, Hi] = DAG.SplitVector(Vec, DL);
VecEVT = Lo.getValueType();
Vec = DAG.getNode(BaseOpc, DL, VecEVT, Lo, Hi);
}
// TODO: The type may need to be widened rather than split. Or widened before
// it can be split.
if (!isTypeLegal(VecEVT))
return SDValue();
MVT VecVT = VecEVT.getSimpleVT();
MVT VecEltVT = VecVT.getVectorElementType();
unsigned RVVOpcode = getRVVReductionOp(Op.getOpcode());
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
auto [Mask, VL] = getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget);
SDValue NeutralElem =
DAG.getNeutralElement(BaseOpc, DL, VecEltVT, SDNodeFlags());
return lowerReductionSeq(RVVOpcode, Op.getSimpleValueType(), NeutralElem, Vec,
Mask, VL, DL, DAG, Subtarget);
}
// Given a reduction op, this function returns the matching reduction opcode,
// the vector SDValue and the scalar SDValue required to lower this to a
// RISCVISD node.
static std::tuple<unsigned, SDValue, SDValue>
getRVVFPReductionOpAndOperands(SDValue Op, SelectionDAG &DAG, EVT EltVT) {
SDLoc DL(Op);
auto Flags = Op->getFlags();
unsigned Opcode = Op.getOpcode();
unsigned BaseOpcode = ISD::getVecReduceBaseOpcode(Opcode);
switch (Opcode) {
default:
llvm_unreachable("Unhandled reduction");
case ISD::VECREDUCE_FADD: {
// Use positive zero if we can. It is cheaper to materialize.
SDValue Zero =
DAG.getConstantFP(Flags.hasNoSignedZeros() ? 0.0 : -0.0, DL, EltVT);
return std::make_tuple(RISCVISD::VECREDUCE_FADD_VL, Op.getOperand(0), Zero);
}
case ISD::VECREDUCE_SEQ_FADD:
return std::make_tuple(RISCVISD::VECREDUCE_SEQ_FADD_VL, Op.getOperand(1),
Op.getOperand(0));
case ISD::VECREDUCE_FMIN:
return std::make_tuple(RISCVISD::VECREDUCE_FMIN_VL, Op.getOperand(0),
DAG.getNeutralElement(BaseOpcode, DL, EltVT, Flags));
case ISD::VECREDUCE_FMAX:
return std::make_tuple(RISCVISD::VECREDUCE_FMAX_VL, Op.getOperand(0),
DAG.getNeutralElement(BaseOpcode, DL, EltVT, Flags));
}
}
SDValue RISCVTargetLowering::lowerFPVECREDUCE(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VecEltVT = Op.getSimpleValueType();
unsigned RVVOpcode;
SDValue VectorVal, ScalarVal;
std::tie(RVVOpcode, VectorVal, ScalarVal) =
getRVVFPReductionOpAndOperands(Op, DAG, VecEltVT);
MVT VecVT = VectorVal.getSimpleValueType();
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
VectorVal = convertToScalableVector(ContainerVT, VectorVal, DAG, Subtarget);
}
auto [Mask, VL] = getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget);
return lowerReductionSeq(RVVOpcode, Op.getSimpleValueType(), ScalarVal,
VectorVal, Mask, VL, DL, DAG, Subtarget);
}
static unsigned getRVVVPReductionOp(unsigned ISDOpcode) {
switch (ISDOpcode) {
default:
llvm_unreachable("Unhandled reduction");
case ISD::VP_REDUCE_ADD:
return RISCVISD::VECREDUCE_ADD_VL;
case ISD::VP_REDUCE_UMAX:
return RISCVISD::VECREDUCE_UMAX_VL;
case ISD::VP_REDUCE_SMAX:
return RISCVISD::VECREDUCE_SMAX_VL;
case ISD::VP_REDUCE_UMIN:
return RISCVISD::VECREDUCE_UMIN_VL;
case ISD::VP_REDUCE_SMIN:
return RISCVISD::VECREDUCE_SMIN_VL;
case ISD::VP_REDUCE_AND:
return RISCVISD::VECREDUCE_AND_VL;
case ISD::VP_REDUCE_OR:
return RISCVISD::VECREDUCE_OR_VL;
case ISD::VP_REDUCE_XOR:
return RISCVISD::VECREDUCE_XOR_VL;
case ISD::VP_REDUCE_FADD:
return RISCVISD::VECREDUCE_FADD_VL;
case ISD::VP_REDUCE_SEQ_FADD:
return RISCVISD::VECREDUCE_SEQ_FADD_VL;
case ISD::VP_REDUCE_FMAX:
return RISCVISD::VECREDUCE_FMAX_VL;
case ISD::VP_REDUCE_FMIN:
return RISCVISD::VECREDUCE_FMIN_VL;
}
}
SDValue RISCVTargetLowering::lowerVPREDUCE(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
SDValue Vec = Op.getOperand(1);
EVT VecEVT = Vec.getValueType();
// TODO: The type may need to be widened rather than split. Or widened before
// it can be split.
if (!isTypeLegal(VecEVT))
return SDValue();
MVT VecVT = VecEVT.getSimpleVT();
unsigned RVVOpcode = getRVVVPReductionOp(Op.getOpcode());
if (VecVT.isFixedLengthVector()) {
auto ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
SDValue VL = Op.getOperand(3);
SDValue Mask = Op.getOperand(2);
return lowerReductionSeq(RVVOpcode, Op.getSimpleValueType(), Op.getOperand(0),
Vec, Mask, VL, DL, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerINSERT_SUBVECTOR(SDValue Op,
SelectionDAG &DAG) const {
SDValue Vec = Op.getOperand(0);
SDValue SubVec = Op.getOperand(1);
MVT VecVT = Vec.getSimpleValueType();
MVT SubVecVT = SubVec.getSimpleValueType();
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
unsigned OrigIdx = Op.getConstantOperandVal(2);
const RISCVRegisterInfo *TRI = Subtarget.getRegisterInfo();
// We don't have the ability to slide mask vectors up indexed by their i1
// elements; the smallest we can do is i8. Often we are able to bitcast to
// equivalent i8 vectors. Note that when inserting a fixed-length vector
// into a scalable one, we might not necessarily have enough scalable
// elements to safely divide by 8: nxv1i1 = insert nxv1i1, v4i1 is valid.
if (SubVecVT.getVectorElementType() == MVT::i1 &&
(OrigIdx != 0 || !Vec.isUndef())) {
if (VecVT.getVectorMinNumElements() >= 8 &&
SubVecVT.getVectorMinNumElements() >= 8) {
assert(OrigIdx % 8 == 0 && "Invalid index");
assert(VecVT.getVectorMinNumElements() % 8 == 0 &&
SubVecVT.getVectorMinNumElements() % 8 == 0 &&
"Unexpected mask vector lowering");
OrigIdx /= 8;
SubVecVT =
MVT::getVectorVT(MVT::i8, SubVecVT.getVectorMinNumElements() / 8,
SubVecVT.isScalableVector());
VecVT = MVT::getVectorVT(MVT::i8, VecVT.getVectorMinNumElements() / 8,
VecVT.isScalableVector());
Vec = DAG.getBitcast(VecVT, Vec);
SubVec = DAG.getBitcast(SubVecVT, SubVec);
} else {
// We can't slide this mask vector up indexed by its i1 elements.
// This poses a problem when we wish to insert a scalable vector which
// can't be re-expressed as a larger type. Just choose the slow path and
// extend to a larger type, then truncate back down.
MVT ExtVecVT = VecVT.changeVectorElementType(MVT::i8);
MVT ExtSubVecVT = SubVecVT.changeVectorElementType(MVT::i8);
Vec = DAG.getNode(ISD::ZERO_EXTEND, DL, ExtVecVT, Vec);
SubVec = DAG.getNode(ISD::ZERO_EXTEND, DL, ExtSubVecVT, SubVec);
Vec = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, ExtVecVT, Vec, SubVec,
Op.getOperand(2));
SDValue SplatZero = DAG.getConstant(0, DL, ExtVecVT);
return DAG.getSetCC(DL, VecVT, Vec, SplatZero, ISD::SETNE);
}
}
// If the subvector vector is a fixed-length type, we cannot use subregister
// manipulation to simplify the codegen; we don't know which register of a
// LMUL group contains the specific subvector as we only know the minimum
// register size. Therefore we must slide the vector group up the full
// amount.
if (SubVecVT.isFixedLengthVector()) {
if (OrigIdx == 0 && Vec.isUndef() && !VecVT.isFixedLengthVector())
return Op;
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
SubVec = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), SubVec,
DAG.getConstant(0, DL, XLenVT));
if (OrigIdx == 0 && Vec.isUndef() && VecVT.isFixedLengthVector()) {
SubVec = convertFromScalableVector(VecVT, SubVec, DAG, Subtarget);
return DAG.getBitcast(Op.getValueType(), SubVec);
}
SDValue Mask =
getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget).first;
// Set the vector length to only the number of elements we care about. Note
// that for slideup this includes the offset.
unsigned EndIndex = OrigIdx + SubVecVT.getVectorNumElements();
SDValue VL = getVLOp(EndIndex, DL, DAG, Subtarget);
SDValue SlideupAmt = DAG.getConstant(OrigIdx, DL, XLenVT);
// Use tail agnostic policy if we're inserting over Vec's tail.
unsigned Policy = RISCVII::TAIL_UNDISTURBED_MASK_UNDISTURBED;
if (VecVT.isFixedLengthVector() && EndIndex == VecVT.getVectorNumElements())
Policy = RISCVII::TAIL_AGNOSTIC;
SDValue Slideup = getVSlideup(DAG, Subtarget, DL, ContainerVT, Vec, SubVec,
SlideupAmt, Mask, VL, Policy);
if (VecVT.isFixedLengthVector())
Slideup = convertFromScalableVector(VecVT, Slideup, DAG, Subtarget);
return DAG.getBitcast(Op.getValueType(), Slideup);
}
unsigned SubRegIdx, RemIdx;
std::tie(SubRegIdx, RemIdx) =
RISCVTargetLowering::decomposeSubvectorInsertExtractToSubRegs(
VecVT, SubVecVT, OrigIdx, TRI);
RISCVII::VLMUL SubVecLMUL = RISCVTargetLowering::getLMUL(SubVecVT);
bool IsSubVecPartReg = SubVecLMUL == RISCVII::VLMUL::LMUL_F2 ||
SubVecLMUL == RISCVII::VLMUL::LMUL_F4 ||
SubVecLMUL == RISCVII::VLMUL::LMUL_F8;
// 1. If the Idx has been completely eliminated and this subvector's size is
// a vector register or a multiple thereof, or the surrounding elements are
// undef, then this is a subvector insert which naturally aligns to a vector
// register. These can easily be handled using subregister manipulation.
// 2. If the subvector is smaller than a vector register, then the insertion
// must preserve the undisturbed elements of the register. We do this by
// lowering to an EXTRACT_SUBVECTOR grabbing the nearest LMUL=1 vector type
// (which resolves to a subregister copy), performing a VSLIDEUP to place the
// subvector within the vector register, and an INSERT_SUBVECTOR of that
// LMUL=1 type back into the larger vector (resolving to another subregister
// operation). See below for how our VSLIDEUP works. We go via a LMUL=1 type
// to avoid allocating a large register group to hold our subvector.
if (RemIdx == 0 && (!IsSubVecPartReg || Vec.isUndef()))
return Op;
// VSLIDEUP works by leaving elements 0<i<OFFSET undisturbed, elements
// OFFSET<=i<VL set to the "subvector" and vl<=i<VLMAX set to the tail policy
// (in our case undisturbed). This means we can set up a subvector insertion
// where OFFSET is the insertion offset, and the VL is the OFFSET plus the
// size of the subvector.
MVT InterSubVT = VecVT;
SDValue AlignedExtract = Vec;
unsigned AlignedIdx = OrigIdx - RemIdx;
if (VecVT.bitsGT(getLMUL1VT(VecVT))) {
InterSubVT = getLMUL1VT(VecVT);
// Extract a subvector equal to the nearest full vector register type. This
// should resolve to a EXTRACT_SUBREG instruction.
AlignedExtract = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, InterSubVT, Vec,
DAG.getConstant(AlignedIdx, DL, XLenVT));
}
SDValue SlideupAmt = DAG.getConstant(RemIdx, DL, XLenVT);
// For scalable vectors this must be further multiplied by vscale.
SlideupAmt = DAG.getNode(ISD::VSCALE, DL, XLenVT, SlideupAmt);
auto [Mask, VL] = getDefaultScalableVLOps(VecVT, DL, DAG, Subtarget);
// Construct the vector length corresponding to RemIdx + length(SubVecVT).
VL = DAG.getConstant(SubVecVT.getVectorMinNumElements(), DL, XLenVT);
VL = DAG.getNode(ISD::VSCALE, DL, XLenVT, VL);
VL = DAG.getNode(ISD::ADD, DL, XLenVT, SlideupAmt, VL);
SubVec = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, InterSubVT,
DAG.getUNDEF(InterSubVT), SubVec,
DAG.getConstant(0, DL, XLenVT));
SDValue Slideup = getVSlideup(DAG, Subtarget, DL, InterSubVT, AlignedExtract,
SubVec, SlideupAmt, Mask, VL);
// If required, insert this subvector back into the correct vector register.
// This should resolve to an INSERT_SUBREG instruction.
if (VecVT.bitsGT(InterSubVT))
Slideup = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VecVT, Vec, Slideup,
DAG.getConstant(AlignedIdx, DL, XLenVT));
// We might have bitcast from a mask type: cast back to the original type if
// required.
return DAG.getBitcast(Op.getSimpleValueType(), Slideup);
}
SDValue RISCVTargetLowering::lowerEXTRACT_SUBVECTOR(SDValue Op,
SelectionDAG &DAG) const {
SDValue Vec = Op.getOperand(0);
MVT SubVecVT = Op.getSimpleValueType();
MVT VecVT = Vec.getSimpleValueType();
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
unsigned OrigIdx = Op.getConstantOperandVal(1);
const RISCVRegisterInfo *TRI = Subtarget.getRegisterInfo();
// We don't have the ability to slide mask vectors down indexed by their i1
// elements; the smallest we can do is i8. Often we are able to bitcast to
// equivalent i8 vectors. Note that when extracting a fixed-length vector
// from a scalable one, we might not necessarily have enough scalable
// elements to safely divide by 8: v8i1 = extract nxv1i1 is valid.
if (SubVecVT.getVectorElementType() == MVT::i1 && OrigIdx != 0) {
if (VecVT.getVectorMinNumElements() >= 8 &&
SubVecVT.getVectorMinNumElements() >= 8) {
assert(OrigIdx % 8 == 0 && "Invalid index");
assert(VecVT.getVectorMinNumElements() % 8 == 0 &&
SubVecVT.getVectorMinNumElements() % 8 == 0 &&
"Unexpected mask vector lowering");
OrigIdx /= 8;
SubVecVT =
MVT::getVectorVT(MVT::i8, SubVecVT.getVectorMinNumElements() / 8,
SubVecVT.isScalableVector());
VecVT = MVT::getVectorVT(MVT::i8, VecVT.getVectorMinNumElements() / 8,
VecVT.isScalableVector());
Vec = DAG.getBitcast(VecVT, Vec);
} else {
// We can't slide this mask vector down, indexed by its i1 elements.
// This poses a problem when we wish to extract a scalable vector which
// can't be re-expressed as a larger type. Just choose the slow path and
// extend to a larger type, then truncate back down.
// TODO: We could probably improve this when extracting certain fixed
// from fixed, where we can extract as i8 and shift the correct element
// right to reach the desired subvector?
MVT ExtVecVT = VecVT.changeVectorElementType(MVT::i8);
MVT ExtSubVecVT = SubVecVT.changeVectorElementType(MVT::i8);
Vec = DAG.getNode(ISD::ZERO_EXTEND, DL, ExtVecVT, Vec);
Vec = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, ExtSubVecVT, Vec,
Op.getOperand(1));
SDValue SplatZero = DAG.getConstant(0, DL, ExtSubVecVT);
return DAG.getSetCC(DL, SubVecVT, Vec, SplatZero, ISD::SETNE);
}
}
// If the subvector vector is a fixed-length type, we cannot use subregister
// manipulation to simplify the codegen; we don't know which register of a
// LMUL group contains the specific subvector as we only know the minimum
// register size. Therefore we must slide the vector group down the full
// amount.
if (SubVecVT.isFixedLengthVector()) {
// With an index of 0 this is a cast-like subvector, which can be performed
// with subregister operations.
if (OrigIdx == 0)
return Op;
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
SDValue Mask =
getDefaultVLOps(VecVT, ContainerVT, DL, DAG, Subtarget).first;
// Set the vector length to only the number of elements we care about. This
// avoids sliding down elements we're going to discard straight away.
SDValue VL = getVLOp(SubVecVT.getVectorNumElements(), DL, DAG, Subtarget);
SDValue SlidedownAmt = DAG.getConstant(OrigIdx, DL, XLenVT);
SDValue Slidedown =
getVSlidedown(DAG, Subtarget, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), Vec, SlidedownAmt, Mask, VL);
// Now we can use a cast-like subvector extract to get the result.
Slidedown = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVecVT, Slidedown,
DAG.getConstant(0, DL, XLenVT));
return DAG.getBitcast(Op.getValueType(), Slidedown);
}
unsigned SubRegIdx, RemIdx;
std::tie(SubRegIdx, RemIdx) =
RISCVTargetLowering::decomposeSubvectorInsertExtractToSubRegs(
VecVT, SubVecVT, OrigIdx, TRI);
// If the Idx has been completely eliminated then this is a subvector extract
// which naturally aligns to a vector register. These can easily be handled
// using subregister manipulation.
if (RemIdx == 0)
return Op;
// Else we must shift our vector register directly to extract the subvector.
// Do this using VSLIDEDOWN.
// If the vector type is an LMUL-group type, extract a subvector equal to the
// nearest full vector register type. This should resolve to a EXTRACT_SUBREG
// instruction.
MVT InterSubVT = VecVT;
if (VecVT.bitsGT(getLMUL1VT(VecVT))) {
InterSubVT = getLMUL1VT(VecVT);
Vec = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, InterSubVT, Vec,
DAG.getConstant(OrigIdx - RemIdx, DL, XLenVT));
}
// Slide this vector register down by the desired number of elements in order
// to place the desired subvector starting at element 0.
SDValue SlidedownAmt = DAG.getConstant(RemIdx, DL, XLenVT);
// For scalable vectors this must be further multiplied by vscale.
SlidedownAmt = DAG.getNode(ISD::VSCALE, DL, XLenVT, SlidedownAmt);
auto [Mask, VL] = getDefaultScalableVLOps(InterSubVT, DL, DAG, Subtarget);
SDValue Slidedown =
getVSlidedown(DAG, Subtarget, DL, InterSubVT, DAG.getUNDEF(InterSubVT),
Vec, SlidedownAmt, Mask, VL);
// Now the vector is in the right position, extract our final subvector. This
// should resolve to a COPY.
Slidedown = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVecVT, Slidedown,
DAG.getConstant(0, DL, XLenVT));
// We might have bitcast from a mask type: cast back to the original type if
// required.
return DAG.getBitcast(Op.getSimpleValueType(), Slidedown);
}
// Widen a vector's operands to i8, then truncate its results back to the
// original type, typically i1. All operand and result types must be the same.
static SDValue widenVectorOpsToi8(SDValue N, SDLoc &DL, SelectionDAG &DAG) {
MVT VT = N.getSimpleValueType();
MVT WideVT = VT.changeVectorElementType(MVT::i8);
SmallVector<SDValue, 4> WideOps;
for (SDValue Op : N->ops()) {
assert(Op.getSimpleValueType() == VT &&
"Operands and result must be same type");
WideOps.push_back(DAG.getNode(ISD::ZERO_EXTEND, DL, WideVT, Op));
}
unsigned NumVals = N->getNumValues();
SDVTList VTs = DAG.getVTList(SmallVector<EVT, 4>(
NumVals, N.getValueType().changeVectorElementType(MVT::i8)));
SDValue WideN = DAG.getNode(N.getOpcode(), DL, VTs, WideOps);
SmallVector<SDValue, 4> TruncVals;
for (unsigned I = 0; I < NumVals; I++) {
TruncVals.push_back(DAG.getNode(ISD::TRUNCATE, DL,
N->getSimpleValueType(I),
SDValue(WideN.getNode(), I)));
}
if (TruncVals.size() > 1)
return DAG.getMergeValues(TruncVals, DL);
return TruncVals.front();
}
SDValue RISCVTargetLowering::lowerVECTOR_DEINTERLEAVE(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VecVT = Op.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
assert(VecVT.isScalableVector() &&
"vector_interleave on non-scalable vector!");
// 1 bit element vectors need to be widened to e8
if (VecVT.getVectorElementType() == MVT::i1)
return widenVectorOpsToi8(Op, DL, DAG);
// Concatenate the two vectors as one vector to deinterleave
MVT ConcatVT =
MVT::getVectorVT(VecVT.getVectorElementType(),
VecVT.getVectorElementCount().multiplyCoefficientBy(2));
SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, DL, ConcatVT,
Op.getOperand(0), Op.getOperand(1));
// We want to operate on all lanes, so get the mask and VL and mask for it
auto [Mask, VL] = getDefaultScalableVLOps(ConcatVT, DL, DAG, Subtarget);
SDValue Passthru = DAG.getUNDEF(ConcatVT);
// We can deinterleave through vnsrl.wi if the element type is smaller than
// ELEN
if (VecVT.getScalarSizeInBits() < Subtarget.getELEN()) {
SDValue Even =
getDeinterleaveViaVNSRL(DL, VecVT, Concat, true, Subtarget, DAG);
SDValue Odd =
getDeinterleaveViaVNSRL(DL, VecVT, Concat, false, Subtarget, DAG);
return DAG.getMergeValues({Even, Odd}, DL);
}
// For the indices, use the same SEW to avoid an extra vsetvli
MVT IdxVT = ConcatVT.changeVectorElementTypeToInteger();
// Create a vector of even indices {0, 2, 4, ...}
SDValue EvenIdx =
DAG.getStepVector(DL, IdxVT, APInt(IdxVT.getScalarSizeInBits(), 2));
// Create a vector of odd indices {1, 3, 5, ... }
SDValue OddIdx =
DAG.getNode(ISD::ADD, DL, IdxVT, EvenIdx, DAG.getConstant(1, DL, IdxVT));
// Gather the even and odd elements into two separate vectors
SDValue EvenWide = DAG.getNode(RISCVISD::VRGATHER_VV_VL, DL, ConcatVT,
Concat, EvenIdx, Passthru, Mask, VL);
SDValue OddWide = DAG.getNode(RISCVISD::VRGATHER_VV_VL, DL, ConcatVT,
Concat, OddIdx, Passthru, Mask, VL);
// Extract the result half of the gather for even and odd
SDValue Even = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VecVT, EvenWide,
DAG.getConstant(0, DL, XLenVT));
SDValue Odd = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VecVT, OddWide,
DAG.getConstant(0, DL, XLenVT));
return DAG.getMergeValues({Even, Odd}, DL);
}
SDValue RISCVTargetLowering::lowerVECTOR_INTERLEAVE(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VecVT = Op.getSimpleValueType();
assert(VecVT.isScalableVector() &&
"vector_interleave on non-scalable vector!");
// i1 vectors need to be widened to i8
if (VecVT.getVectorElementType() == MVT::i1)
return widenVectorOpsToi8(Op, DL, DAG);
MVT XLenVT = Subtarget.getXLenVT();
SDValue VL = DAG.getRegister(RISCV::X0, XLenVT);
SDValue Interleaved;
// If the element type is smaller than ELEN, then we can interleave with
// vwaddu.vv and vwmaccu.vx
if (VecVT.getScalarSizeInBits() < Subtarget.getELEN()) {
Interleaved = getWideningInterleave(Op.getOperand(0), Op.getOperand(1), DL,
DAG, Subtarget);
} else {
// Otherwise, fallback to using vrgathere16.vv
MVT ConcatVT =
MVT::getVectorVT(VecVT.getVectorElementType(),
VecVT.getVectorElementCount().multiplyCoefficientBy(2));
SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, DL, ConcatVT,
Op.getOperand(0), Op.getOperand(1));
MVT IdxVT = ConcatVT.changeVectorElementType(MVT::i16);
// 0 1 2 3 4 5 6 7 ...
SDValue StepVec = DAG.getStepVector(DL, IdxVT);
// 1 1 1 1 1 1 1 1 ...
SDValue Ones = DAG.getSplatVector(IdxVT, DL, DAG.getConstant(1, DL, XLenVT));
// 1 0 1 0 1 0 1 0 ...
SDValue OddMask = DAG.getNode(ISD::AND, DL, IdxVT, StepVec, Ones);
OddMask = DAG.getSetCC(
DL, IdxVT.changeVectorElementType(MVT::i1), OddMask,
DAG.getSplatVector(IdxVT, DL, DAG.getConstant(0, DL, XLenVT)),
ISD::CondCode::SETNE);
SDValue VLMax = DAG.getSplatVector(IdxVT, DL, computeVLMax(VecVT, DL, DAG));
// Build up the index vector for interleaving the concatenated vector
// 0 0 1 1 2 2 3 3 ...
SDValue Idx = DAG.getNode(ISD::SRL, DL, IdxVT, StepVec, Ones);
// 0 n 1 n+1 2 n+2 3 n+3 ...
Idx =
DAG.getNode(RISCVISD::ADD_VL, DL, IdxVT, Idx, VLMax, Idx, OddMask, VL);
// Then perform the interleave
// v[0] v[n] v[1] v[n+1] v[2] v[n+2] v[3] v[n+3] ...
Interleaved = DAG.getNode(RISCVISD::VRGATHEREI16_VV_VL, DL, ConcatVT,
Concat, Idx, DAG.getUNDEF(ConcatVT), OddMask, VL);
}
// Extract the two halves from the interleaved result
SDValue Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VecVT, Interleaved,
DAG.getVectorIdxConstant(0, DL));
SDValue Hi = DAG.getNode(
ISD::EXTRACT_SUBVECTOR, DL, VecVT, Interleaved,
DAG.getVectorIdxConstant(VecVT.getVectorMinNumElements(), DL));
return DAG.getMergeValues({Lo, Hi}, DL);
}
// Lower step_vector to the vid instruction. Any non-identity step value must
// be accounted for my manual expansion.
SDValue RISCVTargetLowering::lowerSTEP_VECTOR(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
assert(VT.isScalableVector() && "Expected scalable vector");
MVT XLenVT = Subtarget.getXLenVT();
auto [Mask, VL] = getDefaultScalableVLOps(VT, DL, DAG, Subtarget);
SDValue StepVec = DAG.getNode(RISCVISD::VID_VL, DL, VT, Mask, VL);
uint64_t StepValImm = Op.getConstantOperandVal(0);
if (StepValImm != 1) {
if (isPowerOf2_64(StepValImm)) {
SDValue StepVal =
DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VT, DAG.getUNDEF(VT),
DAG.getConstant(Log2_64(StepValImm), DL, XLenVT), VL);
StepVec = DAG.getNode(ISD::SHL, DL, VT, StepVec, StepVal);
} else {
SDValue StepVal = lowerScalarSplat(
SDValue(), DAG.getConstant(StepValImm, DL, VT.getVectorElementType()),
VL, VT, DL, DAG, Subtarget);
StepVec = DAG.getNode(ISD::MUL, DL, VT, StepVec, StepVal);
}
}
return StepVec;
}
// Implement vector_reverse using vrgather.vv with indices determined by
// subtracting the id of each element from (VLMAX-1). This will convert
// the indices like so:
// (0, 1,..., VLMAX-2, VLMAX-1) -> (VLMAX-1, VLMAX-2,..., 1, 0).
// TODO: This code assumes VLMAX <= 65536 for LMUL=8 SEW=16.
SDValue RISCVTargetLowering::lowerVECTOR_REVERSE(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VecVT = Op.getSimpleValueType();
if (VecVT.getVectorElementType() == MVT::i1) {
MVT WidenVT = MVT::getVectorVT(MVT::i8, VecVT.getVectorElementCount());
SDValue Op1 = DAG.getNode(ISD::ZERO_EXTEND, DL, WidenVT, Op.getOperand(0));
SDValue Op2 = DAG.getNode(ISD::VECTOR_REVERSE, DL, WidenVT, Op1);
return DAG.getNode(ISD::TRUNCATE, DL, VecVT, Op2);
}
unsigned EltSize = VecVT.getScalarSizeInBits();
unsigned MinSize = VecVT.getSizeInBits().getKnownMinValue();
unsigned VectorBitsMax = Subtarget.getRealMaxVLen();
unsigned MaxVLMAX =
RISCVTargetLowering::computeVLMAX(VectorBitsMax, EltSize, MinSize);
unsigned GatherOpc = RISCVISD::VRGATHER_VV_VL;
MVT IntVT = VecVT.changeVectorElementTypeToInteger();
// If this is SEW=8 and VLMAX is potentially more than 256, we need
// to use vrgatherei16.vv.
// TODO: It's also possible to use vrgatherei16.vv for other types to
// decrease register width for the index calculation.
if (MaxVLMAX > 256 && EltSize == 8) {
// If this is LMUL=8, we have to split before can use vrgatherei16.vv.
// Reverse each half, then reassemble them in reverse order.
// NOTE: It's also possible that after splitting that VLMAX no longer
// requires vrgatherei16.vv.
if (MinSize == (8 * RISCV::RVVBitsPerBlock)) {
auto [Lo, Hi] = DAG.SplitVectorOperand(Op.getNode(), 0);
auto [LoVT, HiVT] = DAG.GetSplitDestVTs(VecVT);
Lo = DAG.getNode(ISD::VECTOR_REVERSE, DL, LoVT, Lo);
Hi = DAG.getNode(ISD::VECTOR_REVERSE, DL, HiVT, Hi);
// Reassemble the low and high pieces reversed.
// FIXME: This is a CONCAT_VECTORS.
SDValue Res =
DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VecVT, DAG.getUNDEF(VecVT), Hi,
DAG.getIntPtrConstant(0, DL));
return DAG.getNode(
ISD::INSERT_SUBVECTOR, DL, VecVT, Res, Lo,
DAG.getIntPtrConstant(LoVT.getVectorMinNumElements(), DL));
}
// Just promote the int type to i16 which will double the LMUL.
IntVT = MVT::getVectorVT(MVT::i16, VecVT.getVectorElementCount());
GatherOpc = RISCVISD::VRGATHEREI16_VV_VL;
}
MVT XLenVT = Subtarget.getXLenVT();
auto [Mask, VL] = getDefaultScalableVLOps(VecVT, DL, DAG, Subtarget);
// Calculate VLMAX-1 for the desired SEW.
SDValue VLMinus1 = DAG.getNode(ISD::SUB, DL, XLenVT,
computeVLMax(VecVT, DL, DAG),
DAG.getConstant(1, DL, XLenVT));
// Splat VLMAX-1 taking care to handle SEW==64 on RV32.
bool IsRV32E64 =
!Subtarget.is64Bit() && IntVT.getVectorElementType() == MVT::i64;
SDValue SplatVL;
if (!IsRV32E64)
SplatVL = DAG.getSplatVector(IntVT, DL, VLMinus1);
else
SplatVL = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, IntVT, DAG.getUNDEF(IntVT),
VLMinus1, DAG.getRegister(RISCV::X0, XLenVT));
SDValue VID = DAG.getNode(RISCVISD::VID_VL, DL, IntVT, Mask, VL);
SDValue Indices = DAG.getNode(RISCVISD::SUB_VL, DL, IntVT, SplatVL, VID,
DAG.getUNDEF(IntVT), Mask, VL);
return DAG.getNode(GatherOpc, DL, VecVT, Op.getOperand(0), Indices,
DAG.getUNDEF(VecVT), Mask, VL);
}
SDValue RISCVTargetLowering::lowerVECTOR_SPLICE(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
SDValue V1 = Op.getOperand(0);
SDValue V2 = Op.getOperand(1);
MVT XLenVT = Subtarget.getXLenVT();
MVT VecVT = Op.getSimpleValueType();
SDValue VLMax = computeVLMax(VecVT, DL, DAG);
int64_t ImmValue = cast<ConstantSDNode>(Op.getOperand(2))->getSExtValue();
SDValue DownOffset, UpOffset;
if (ImmValue >= 0) {
// The operand is a TargetConstant, we need to rebuild it as a regular
// constant.
DownOffset = DAG.getConstant(ImmValue, DL, XLenVT);
UpOffset = DAG.getNode(ISD::SUB, DL, XLenVT, VLMax, DownOffset);
} else {
// The operand is a TargetConstant, we need to rebuild it as a regular
// constant rather than negating the original operand.
UpOffset = DAG.getConstant(-ImmValue, DL, XLenVT);
DownOffset = DAG.getNode(ISD::SUB, DL, XLenVT, VLMax, UpOffset);
}
SDValue TrueMask = getAllOnesMask(VecVT, VLMax, DL, DAG);
SDValue SlideDown =
getVSlidedown(DAG, Subtarget, DL, VecVT, DAG.getUNDEF(VecVT), V1,
DownOffset, TrueMask, UpOffset);
return getVSlideup(DAG, Subtarget, DL, VecVT, SlideDown, V2, UpOffset,
TrueMask, DAG.getRegister(RISCV::X0, XLenVT),
RISCVII::TAIL_AGNOSTIC);
}
SDValue
RISCVTargetLowering::lowerFixedLengthVectorLoadToRVV(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
auto *Load = cast<LoadSDNode>(Op);
assert(allowsMemoryAccessForAlignment(*DAG.getContext(), DAG.getDataLayout(),
Load->getMemoryVT(),
*Load->getMemOperand()) &&
"Expecting a correctly-aligned load");
MVT VT = Op.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
MVT ContainerVT = getContainerForFixedLengthVector(VT);
SDValue VL = getVLOp(VT.getVectorNumElements(), DL, DAG, Subtarget);
bool IsMaskOp = VT.getVectorElementType() == MVT::i1;
SDValue IntID = DAG.getTargetConstant(
IsMaskOp ? Intrinsic::riscv_vlm : Intrinsic::riscv_vle, DL, XLenVT);
SmallVector<SDValue, 4> Ops{Load->getChain(), IntID};
if (!IsMaskOp)
Ops.push_back(DAG.getUNDEF(ContainerVT));
Ops.push_back(Load->getBasePtr());
Ops.push_back(VL);
SDVTList VTs = DAG.getVTList({ContainerVT, MVT::Other});
SDValue NewLoad =
DAG.getMemIntrinsicNode(ISD::INTRINSIC_W_CHAIN, DL, VTs, Ops,
Load->getMemoryVT(), Load->getMemOperand());
SDValue Result = convertFromScalableVector(VT, NewLoad, DAG, Subtarget);
return DAG.getMergeValues({Result, NewLoad.getValue(1)}, DL);
}
SDValue
RISCVTargetLowering::lowerFixedLengthVectorStoreToRVV(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
auto *Store = cast<StoreSDNode>(Op);
assert(allowsMemoryAccessForAlignment(*DAG.getContext(), DAG.getDataLayout(),
Store->getMemoryVT(),
*Store->getMemOperand()) &&
"Expecting a correctly-aligned store");
SDValue StoreVal = Store->getValue();
MVT VT = StoreVal.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
// If the size less than a byte, we need to pad with zeros to make a byte.
if (VT.getVectorElementType() == MVT::i1 && VT.getVectorNumElements() < 8) {
VT = MVT::v8i1;
StoreVal = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT,
DAG.getConstant(0, DL, VT), StoreVal,
DAG.getIntPtrConstant(0, DL));
}
MVT ContainerVT = getContainerForFixedLengthVector(VT);
SDValue VL = getVLOp(VT.getVectorNumElements(), DL, DAG, Subtarget);
SDValue NewValue =
convertToScalableVector(ContainerVT, StoreVal, DAG, Subtarget);
bool IsMaskOp = VT.getVectorElementType() == MVT::i1;
SDValue IntID = DAG.getTargetConstant(
IsMaskOp ? Intrinsic::riscv_vsm : Intrinsic::riscv_vse, DL, XLenVT);
return DAG.getMemIntrinsicNode(
ISD::INTRINSIC_VOID, DL, DAG.getVTList(MVT::Other),
{Store->getChain(), IntID, NewValue, Store->getBasePtr(), VL},
Store->getMemoryVT(), Store->getMemOperand());
}
SDValue RISCVTargetLowering::lowerMaskedLoad(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
const auto *MemSD = cast<MemSDNode>(Op);
EVT MemVT = MemSD->getMemoryVT();
MachineMemOperand *MMO = MemSD->getMemOperand();
SDValue Chain = MemSD->getChain();
SDValue BasePtr = MemSD->getBasePtr();
SDValue Mask, PassThru, VL;
if (const auto *VPLoad = dyn_cast<VPLoadSDNode>(Op)) {
Mask = VPLoad->getMask();
PassThru = DAG.getUNDEF(VT);
VL = VPLoad->getVectorLength();
} else {
const auto *MLoad = cast<MaskedLoadSDNode>(Op);
Mask = MLoad->getMask();
PassThru = MLoad->getPassThru();
}
bool IsUnmasked = ISD::isConstantSplatVectorAllOnes(Mask.getNode());
MVT XLenVT = Subtarget.getXLenVT();
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
PassThru = convertToScalableVector(ContainerVT, PassThru, DAG, Subtarget);
if (!IsUnmasked) {
MVT MaskVT = getMaskTypeFor(ContainerVT);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
}
if (!VL)
VL = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).second;
unsigned IntID =
IsUnmasked ? Intrinsic::riscv_vle : Intrinsic::riscv_vle_mask;
SmallVector<SDValue, 8> Ops{Chain, DAG.getTargetConstant(IntID, DL, XLenVT)};
if (IsUnmasked)
Ops.push_back(DAG.getUNDEF(ContainerVT));
else
Ops.push_back(PassThru);
Ops.push_back(BasePtr);
if (!IsUnmasked)
Ops.push_back(Mask);
Ops.push_back(VL);
if (!IsUnmasked)
Ops.push_back(DAG.getTargetConstant(RISCVII::TAIL_AGNOSTIC, DL, XLenVT));
SDVTList VTs = DAG.getVTList({ContainerVT, MVT::Other});
SDValue Result =
DAG.getMemIntrinsicNode(ISD::INTRINSIC_W_CHAIN, DL, VTs, Ops, MemVT, MMO);
Chain = Result.getValue(1);
if (VT.isFixedLengthVector())
Result = convertFromScalableVector(VT, Result, DAG, Subtarget);
return DAG.getMergeValues({Result, Chain}, DL);
}
SDValue RISCVTargetLowering::lowerMaskedStore(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
const auto *MemSD = cast<MemSDNode>(Op);
EVT MemVT = MemSD->getMemoryVT();
MachineMemOperand *MMO = MemSD->getMemOperand();
SDValue Chain = MemSD->getChain();
SDValue BasePtr = MemSD->getBasePtr();
SDValue Val, Mask, VL;
if (const auto *VPStore = dyn_cast<VPStoreSDNode>(Op)) {
Val = VPStore->getValue();
Mask = VPStore->getMask();
VL = VPStore->getVectorLength();
} else {
const auto *MStore = cast<MaskedStoreSDNode>(Op);
Val = MStore->getValue();
Mask = MStore->getMask();
}
bool IsUnmasked = ISD::isConstantSplatVectorAllOnes(Mask.getNode());
MVT VT = Val.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
Val = convertToScalableVector(ContainerVT, Val, DAG, Subtarget);
if (!IsUnmasked) {
MVT MaskVT = getMaskTypeFor(ContainerVT);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
}
if (!VL)
VL = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).second;
unsigned IntID =
IsUnmasked ? Intrinsic::riscv_vse : Intrinsic::riscv_vse_mask;
SmallVector<SDValue, 8> Ops{Chain, DAG.getTargetConstant(IntID, DL, XLenVT)};
Ops.push_back(Val);
Ops.push_back(BasePtr);
if (!IsUnmasked)
Ops.push_back(Mask);
Ops.push_back(VL);
return DAG.getMemIntrinsicNode(ISD::INTRINSIC_VOID, DL,
DAG.getVTList(MVT::Other), Ops, MemVT, MMO);
}
SDValue
RISCVTargetLowering::lowerFixedLengthVectorSetccToRVV(SDValue Op,
SelectionDAG &DAG) const {
MVT InVT = Op.getOperand(0).getSimpleValueType();
MVT ContainerVT = getContainerForFixedLengthVector(InVT);
MVT VT = Op.getSimpleValueType();
SDValue Op1 =
convertToScalableVector(ContainerVT, Op.getOperand(0), DAG, Subtarget);
SDValue Op2 =
convertToScalableVector(ContainerVT, Op.getOperand(1), DAG, Subtarget);
SDLoc DL(Op);
auto [Mask, VL] = getDefaultVLOps(VT.getVectorNumElements(), ContainerVT, DL,
DAG, Subtarget);
MVT MaskVT = getMaskTypeFor(ContainerVT);
SDValue Cmp =
DAG.getNode(RISCVISD::SETCC_VL, DL, MaskVT,
{Op1, Op2, Op.getOperand(2), DAG.getUNDEF(MaskVT), Mask, VL});
return convertFromScalableVector(VT, Cmp, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerVectorStrictFSetcc(SDValue Op,
SelectionDAG &DAG) const {
unsigned Opc = Op.getOpcode();
SDLoc DL(Op);
SDValue Chain = Op.getOperand(0);
SDValue Op1 = Op.getOperand(1);
SDValue Op2 = Op.getOperand(2);
SDValue CC = Op.getOperand(3);
ISD::CondCode CCVal = cast<CondCodeSDNode>(CC)->get();
MVT VT = Op.getSimpleValueType();
MVT InVT = Op1.getSimpleValueType();
// RVV VMFEQ/VMFNE ignores qNan, so we expand strict_fsetccs with OEQ/UNE
// condition code.
if (Opc == ISD::STRICT_FSETCCS) {
// Expand strict_fsetccs(x, oeq) to
// (and strict_fsetccs(x, y, oge), strict_fsetccs(x, y, ole))
SDVTList VTList = Op->getVTList();
if (CCVal == ISD::SETEQ || CCVal == ISD::SETOEQ) {
SDValue OLECCVal = DAG.getCondCode(ISD::SETOLE);
SDValue Tmp1 = DAG.getNode(ISD::STRICT_FSETCCS, DL, VTList, Chain, Op1,
Op2, OLECCVal);
SDValue Tmp2 = DAG.getNode(ISD::STRICT_FSETCCS, DL, VTList, Chain, Op2,
Op1, OLECCVal);
SDValue And = DAG.getNode(ISD::AND, DL, VT, Tmp1, Tmp2);
SDValue OutChain =
DAG.getMergeValues({Tmp1.getValue(1), Tmp2.getValue(1)}, DL);
return DAG.getMergeValues({And, OutChain}, DL);
}
// Expand (strict_fsetccs x, y, une) to (not (strict_fsetccs x, y, oeq))
if (CCVal == ISD::SETNE || CCVal == ISD::SETUNE) {
SDValue OEQCCVal = DAG.getCondCode(ISD::SETOEQ);
SDValue OEQ = DAG.getNode(ISD::STRICT_FSETCCS, DL, VTList, Chain, Op1,
Op2, OEQCCVal);
SDValue Res = DAG.getNOT(DL, OEQ, VT);
return DAG.getMergeValues({Res, OEQ.getValue(1)}, DL);
}
}
MVT ContainerInVT = InVT;
if (InVT.isFixedLengthVector()) {
ContainerInVT = getContainerForFixedLengthVector(InVT);
Op1 = convertToScalableVector(ContainerInVT, Op1, DAG, Subtarget);
Op2 = convertToScalableVector(ContainerInVT, Op2, DAG, Subtarget);
}
MVT MaskVT = getMaskTypeFor(ContainerInVT);
auto [Mask, VL] = getDefaultVLOps(InVT, ContainerInVT, DL, DAG, Subtarget);
SDValue Res;
if (Opc == ISD::STRICT_FSETCC &&
(CCVal == ISD::SETLT || CCVal == ISD::SETOLT || CCVal == ISD::SETLE ||
CCVal == ISD::SETOLE)) {
// VMFLT/VMFLE/VMFGT/VMFGE raise exception for qNan. Generate a mask to only
// active when both input elements are ordered.
SDValue True = getAllOnesMask(ContainerInVT, VL, DL, DAG);
SDValue OrderMask1 = DAG.getNode(
RISCVISD::STRICT_FSETCC_VL, DL, DAG.getVTList(MaskVT, MVT::Other),
{Chain, Op1, Op1, DAG.getCondCode(ISD::SETOEQ), DAG.getUNDEF(MaskVT),
True, VL});
SDValue OrderMask2 = DAG.getNode(
RISCVISD::STRICT_FSETCC_VL, DL, DAG.getVTList(MaskVT, MVT::Other),
{Chain, Op2, Op2, DAG.getCondCode(ISD::SETOEQ), DAG.getUNDEF(MaskVT),
True, VL});
Mask =
DAG.getNode(RISCVISD::VMAND_VL, DL, MaskVT, OrderMask1, OrderMask2, VL);
// Use Mask as the merge operand to let the result be 0 if either of the
// inputs is unordered.
Res = DAG.getNode(RISCVISD::STRICT_FSETCCS_VL, DL,
DAG.getVTList(MaskVT, MVT::Other),
{Chain, Op1, Op2, CC, Mask, Mask, VL});
} else {
unsigned RVVOpc = Opc == ISD::STRICT_FSETCC ? RISCVISD::STRICT_FSETCC_VL
: RISCVISD::STRICT_FSETCCS_VL;
Res = DAG.getNode(RVVOpc, DL, DAG.getVTList(MaskVT, MVT::Other),
{Chain, Op1, Op2, CC, DAG.getUNDEF(MaskVT), Mask, VL});
}
if (VT.isFixedLengthVector()) {
SDValue SubVec = convertFromScalableVector(VT, Res, DAG, Subtarget);
return DAG.getMergeValues({SubVec, Res.getValue(1)}, DL);
}
return Res;
}
SDValue RISCVTargetLowering::lowerFixedLengthVectorLogicOpToRVV(
SDValue Op, SelectionDAG &DAG, unsigned MaskOpc, unsigned VecOpc) const {
MVT VT = Op.getSimpleValueType();
if (VT.getVectorElementType() == MVT::i1)
return lowerToScalableOp(Op, DAG, MaskOpc, /*HasMergeOp*/ false,
/*HasMask*/ false);
return lowerToScalableOp(Op, DAG, VecOpc, /*HasMergeOp*/ true);
}
SDValue
RISCVTargetLowering::lowerFixedLengthVectorShiftToRVV(SDValue Op,
SelectionDAG &DAG) const {
unsigned Opc;
switch (Op.getOpcode()) {
default: llvm_unreachable("Unexpected opcode!");
case ISD::SHL: Opc = RISCVISD::SHL_VL; break;
case ISD::SRA: Opc = RISCVISD::SRA_VL; break;
case ISD::SRL: Opc = RISCVISD::SRL_VL; break;
}
return lowerToScalableOp(Op, DAG, Opc, /*HasMergeOp*/ true);
}
// Lower vector ABS to smax(X, sub(0, X)).
SDValue RISCVTargetLowering::lowerABS(SDValue Op, SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
SDValue X = Op.getOperand(0);
assert((Op.getOpcode() == ISD::VP_ABS || VT.isFixedLengthVector()) &&
"Unexpected type for ISD::ABS");
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
X = convertToScalableVector(ContainerVT, X, DAG, Subtarget);
}
SDValue Mask, VL;
if (Op->getOpcode() == ISD::VP_ABS) {
Mask = Op->getOperand(1);
VL = Op->getOperand(2);
} else
std::tie(Mask, VL) = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
SDValue SplatZero = DAG.getNode(
RISCVISD::VMV_V_X_VL, DL, ContainerVT, DAG.getUNDEF(ContainerVT),
DAG.getConstant(0, DL, Subtarget.getXLenVT()), VL);
SDValue NegX = DAG.getNode(RISCVISD::SUB_VL, DL, ContainerVT, SplatZero, X,
DAG.getUNDEF(ContainerVT), Mask, VL);
SDValue Max = DAG.getNode(RISCVISD::SMAX_VL, DL, ContainerVT, X, NegX,
DAG.getUNDEF(ContainerVT), Mask, VL);
if (VT.isFixedLengthVector())
Max = convertFromScalableVector(VT, Max, DAG, Subtarget);
return Max;
}
SDValue RISCVTargetLowering::lowerFixedLengthVectorFCOPYSIGNToRVV(
SDValue Op, SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
SDValue Mag = Op.getOperand(0);
SDValue Sign = Op.getOperand(1);
assert(Mag.getValueType() == Sign.getValueType() &&
"Can only handle COPYSIGN with matching types.");
MVT ContainerVT = getContainerForFixedLengthVector(VT);
Mag = convertToScalableVector(ContainerVT, Mag, DAG, Subtarget);
Sign = convertToScalableVector(ContainerVT, Sign, DAG, Subtarget);
auto [Mask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
SDValue CopySign = DAG.getNode(RISCVISD::FCOPYSIGN_VL, DL, ContainerVT, Mag,
Sign, DAG.getUNDEF(ContainerVT), Mask, VL);
return convertFromScalableVector(VT, CopySign, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerFixedLengthVectorSelectToRVV(
SDValue Op, SelectionDAG &DAG) const {
MVT VT = Op.getSimpleValueType();
MVT ContainerVT = getContainerForFixedLengthVector(VT);
MVT I1ContainerVT =
MVT::getVectorVT(MVT::i1, ContainerVT.getVectorElementCount());
SDValue CC =
convertToScalableVector(I1ContainerVT, Op.getOperand(0), DAG, Subtarget);
SDValue Op1 =
convertToScalableVector(ContainerVT, Op.getOperand(1), DAG, Subtarget);
SDValue Op2 =
convertToScalableVector(ContainerVT, Op.getOperand(2), DAG, Subtarget);
SDLoc DL(Op);
SDValue VL = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).second;
SDValue Select =
DAG.getNode(RISCVISD::VSELECT_VL, DL, ContainerVT, CC, Op1, Op2, VL);
return convertFromScalableVector(VT, Select, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerToScalableOp(SDValue Op, SelectionDAG &DAG,
unsigned NewOpc, bool HasMergeOp,
bool HasMask) const {
MVT VT = Op.getSimpleValueType();
MVT ContainerVT = getContainerForFixedLengthVector(VT);
// Create list of operands by converting existing ones to scalable types.
SmallVector<SDValue, 6> Ops;
for (const SDValue &V : Op->op_values()) {
assert(!isa<VTSDNode>(V) && "Unexpected VTSDNode node!");
// Pass through non-vector operands.
if (!V.getValueType().isVector()) {
Ops.push_back(V);
continue;
}
// "cast" fixed length vector to a scalable vector.
assert(useRVVForFixedLengthVectorVT(V.getSimpleValueType()) &&
"Only fixed length vectors are supported!");
Ops.push_back(convertToScalableVector(ContainerVT, V, DAG, Subtarget));
}
SDLoc DL(Op);
auto [Mask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
if (HasMergeOp)
Ops.push_back(DAG.getUNDEF(ContainerVT));
if (HasMask)
Ops.push_back(Mask);
Ops.push_back(VL);
// StrictFP operations have two result values. Their lowered result should
// have same result count.
if (Op->isStrictFPOpcode()) {
SDValue ScalableRes =
DAG.getNode(NewOpc, DL, DAG.getVTList(ContainerVT, MVT::Other), Ops,
Op->getFlags());
SDValue SubVec = convertFromScalableVector(VT, ScalableRes, DAG, Subtarget);
return DAG.getMergeValues({SubVec, ScalableRes.getValue(1)}, DL);
}
SDValue ScalableRes =
DAG.getNode(NewOpc, DL, ContainerVT, Ops, Op->getFlags());
return convertFromScalableVector(VT, ScalableRes, DAG, Subtarget);
}
// Lower a VP_* ISD node to the corresponding RISCVISD::*_VL node:
// * Operands of each node are assumed to be in the same order.
// * The EVL operand is promoted from i32 to i64 on RV64.
// * Fixed-length vectors are converted to their scalable-vector container
// types.
SDValue RISCVTargetLowering::lowerVPOp(SDValue Op, SelectionDAG &DAG,
unsigned RISCVISDOpc,
bool HasMergeOp) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
SmallVector<SDValue, 4> Ops;
MVT ContainerVT = VT;
if (VT.isFixedLengthVector())
ContainerVT = getContainerForFixedLengthVector(VT);
for (const auto &OpIdx : enumerate(Op->ops())) {
SDValue V = OpIdx.value();
assert(!isa<VTSDNode>(V) && "Unexpected VTSDNode node!");
// Add dummy merge value before the mask.
if (HasMergeOp && *ISD::getVPMaskIdx(Op.getOpcode()) == OpIdx.index())
Ops.push_back(DAG.getUNDEF(ContainerVT));
// Pass through operands which aren't fixed-length vectors.
if (!V.getValueType().isFixedLengthVector()) {
Ops.push_back(V);
continue;
}
// "cast" fixed length vector to a scalable vector.
MVT OpVT = V.getSimpleValueType();
MVT ContainerVT = getContainerForFixedLengthVector(OpVT);
assert(useRVVForFixedLengthVectorVT(OpVT) &&
"Only fixed length vectors are supported!");
Ops.push_back(convertToScalableVector(ContainerVT, V, DAG, Subtarget));
}
if (!VT.isFixedLengthVector())
return DAG.getNode(RISCVISDOpc, DL, VT, Ops, Op->getFlags());
SDValue VPOp = DAG.getNode(RISCVISDOpc, DL, ContainerVT, Ops, Op->getFlags());
return convertFromScalableVector(VT, VPOp, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerVPExtMaskOp(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
SDValue Src = Op.getOperand(0);
// NOTE: Mask is dropped.
SDValue VL = Op.getOperand(2);
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
MVT SrcVT = MVT::getVectorVT(MVT::i1, ContainerVT.getVectorElementCount());
Src = convertToScalableVector(SrcVT, Src, DAG, Subtarget);
}
MVT XLenVT = Subtarget.getXLenVT();
SDValue Zero = DAG.getConstant(0, DL, XLenVT);
SDValue ZeroSplat = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), Zero, VL);
SDValue SplatValue = DAG.getConstant(
Op.getOpcode() == ISD::VP_ZERO_EXTEND ? 1 : -1, DL, XLenVT);
SDValue Splat = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), SplatValue, VL);
SDValue Result = DAG.getNode(RISCVISD::VSELECT_VL, DL, ContainerVT, Src,
Splat, ZeroSplat, VL);
if (!VT.isFixedLengthVector())
return Result;
return convertFromScalableVector(VT, Result, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerVPSetCCMaskOp(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
SDValue Op1 = Op.getOperand(0);
SDValue Op2 = Op.getOperand(1);
ISD::CondCode Condition = cast<CondCodeSDNode>(Op.getOperand(2))->get();
// NOTE: Mask is dropped.
SDValue VL = Op.getOperand(4);
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
Op1 = convertToScalableVector(ContainerVT, Op1, DAG, Subtarget);
Op2 = convertToScalableVector(ContainerVT, Op2, DAG, Subtarget);
}
SDValue Result;
SDValue AllOneMask = DAG.getNode(RISCVISD::VMSET_VL, DL, ContainerVT, VL);
switch (Condition) {
default:
break;
// X != Y --> (X^Y)
case ISD::SETNE:
Result = DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Op1, Op2, VL);
break;
// X == Y --> ~(X^Y)
case ISD::SETEQ: {
SDValue Temp =
DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Op1, Op2, VL);
Result =
DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Temp, AllOneMask, VL);
break;
}
// X >s Y --> X == 0 & Y == 1 --> ~X & Y
// X <u Y --> X == 0 & Y == 1 --> ~X & Y
case ISD::SETGT:
case ISD::SETULT: {
SDValue Temp =
DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Op1, AllOneMask, VL);
Result = DAG.getNode(RISCVISD::VMAND_VL, DL, ContainerVT, Temp, Op2, VL);
break;
}
// X <s Y --> X == 1 & Y == 0 --> ~Y & X
// X >u Y --> X == 1 & Y == 0 --> ~Y & X
case ISD::SETLT:
case ISD::SETUGT: {
SDValue Temp =
DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Op2, AllOneMask, VL);
Result = DAG.getNode(RISCVISD::VMAND_VL, DL, ContainerVT, Op1, Temp, VL);
break;
}
// X >=s Y --> X == 0 | Y == 1 --> ~X | Y
// X <=u Y --> X == 0 | Y == 1 --> ~X | Y
case ISD::SETGE:
case ISD::SETULE: {
SDValue Temp =
DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Op1, AllOneMask, VL);
Result = DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Temp, Op2, VL);
break;
}
// X <=s Y --> X == 1 | Y == 0 --> ~Y | X
// X >=u Y --> X == 1 | Y == 0 --> ~Y | X
case ISD::SETLE:
case ISD::SETUGE: {
SDValue Temp =
DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Op2, AllOneMask, VL);
Result = DAG.getNode(RISCVISD::VMXOR_VL, DL, ContainerVT, Temp, Op1, VL);
break;
}
}
if (!VT.isFixedLengthVector())
return Result;
return convertFromScalableVector(VT, Result, DAG, Subtarget);
}
// Lower Floating-Point/Integer Type-Convert VP SDNodes
SDValue RISCVTargetLowering::lowerVPFPIntConvOp(SDValue Op, SelectionDAG &DAG,
unsigned RISCVISDOpc) const {
SDLoc DL(Op);
SDValue Src = Op.getOperand(0);
SDValue Mask = Op.getOperand(1);
SDValue VL = Op.getOperand(2);
MVT DstVT = Op.getSimpleValueType();
MVT SrcVT = Src.getSimpleValueType();
if (DstVT.isFixedLengthVector()) {
DstVT = getContainerForFixedLengthVector(DstVT);
SrcVT = getContainerForFixedLengthVector(SrcVT);
Src = convertToScalableVector(SrcVT, Src, DAG, Subtarget);
MVT MaskVT = getMaskTypeFor(DstVT);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
unsigned DstEltSize = DstVT.getScalarSizeInBits();
unsigned SrcEltSize = SrcVT.getScalarSizeInBits();
SDValue Result;
if (DstEltSize >= SrcEltSize) { // Single-width and widening conversion.
if (SrcVT.isInteger()) {
assert(DstVT.isFloatingPoint() && "Wrong input/output vector types");
unsigned RISCVISDExtOpc = RISCVISDOpc == RISCVISD::SINT_TO_FP_VL
? RISCVISD::VSEXT_VL
: RISCVISD::VZEXT_VL;
// Do we need to do any pre-widening before converting?
if (SrcEltSize == 1) {
MVT IntVT = DstVT.changeVectorElementTypeToInteger();
MVT XLenVT = Subtarget.getXLenVT();
SDValue Zero = DAG.getConstant(0, DL, XLenVT);
SDValue ZeroSplat = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, IntVT,
DAG.getUNDEF(IntVT), Zero, VL);
SDValue One = DAG.getConstant(
RISCVISDExtOpc == RISCVISD::VZEXT_VL ? 1 : -1, DL, XLenVT);
SDValue OneSplat = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, IntVT,
DAG.getUNDEF(IntVT), One, VL);
Src = DAG.getNode(RISCVISD::VSELECT_VL, DL, IntVT, Src, OneSplat,
ZeroSplat, VL);
} else if (DstEltSize > (2 * SrcEltSize)) {
// Widen before converting.
MVT IntVT = MVT::getVectorVT(MVT::getIntegerVT(DstEltSize / 2),
DstVT.getVectorElementCount());
Src = DAG.getNode(RISCVISDExtOpc, DL, IntVT, Src, Mask, VL);
}
Result = DAG.getNode(RISCVISDOpc, DL, DstVT, Src, Mask, VL);
} else {
assert(SrcVT.isFloatingPoint() && DstVT.isInteger() &&
"Wrong input/output vector types");
// Convert f16 to f32 then convert f32 to i64.
if (DstEltSize > (2 * SrcEltSize)) {
assert(SrcVT.getVectorElementType() == MVT::f16 && "Unexpected type!");
MVT InterimFVT =
MVT::getVectorVT(MVT::f32, DstVT.getVectorElementCount());
Src =
DAG.getNode(RISCVISD::FP_EXTEND_VL, DL, InterimFVT, Src, Mask, VL);
}
Result = DAG.getNode(RISCVISDOpc, DL, DstVT, Src, Mask, VL);
}
} else { // Narrowing + Conversion
if (SrcVT.isInteger()) {
assert(DstVT.isFloatingPoint() && "Wrong input/output vector types");
// First do a narrowing convert to an FP type half the size, then round
// the FP type to a small FP type if needed.
MVT InterimFVT = DstVT;
if (SrcEltSize > (2 * DstEltSize)) {
assert(SrcEltSize == (4 * DstEltSize) && "Unexpected types!");
assert(DstVT.getVectorElementType() == MVT::f16 && "Unexpected type!");
InterimFVT = MVT::getVectorVT(MVT::f32, DstVT.getVectorElementCount());
}
Result = DAG.getNode(RISCVISDOpc, DL, InterimFVT, Src, Mask, VL);
if (InterimFVT != DstVT) {
Src = Result;
Result = DAG.getNode(RISCVISD::FP_ROUND_VL, DL, DstVT, Src, Mask, VL);
}
} else {
assert(SrcVT.isFloatingPoint() && DstVT.isInteger() &&
"Wrong input/output vector types");
// First do a narrowing conversion to an integer half the size, then
// truncate if needed.
if (DstEltSize == 1) {
// First convert to the same size integer, then convert to mask using
// setcc.
assert(SrcEltSize >= 16 && "Unexpected FP type!");
MVT InterimIVT = MVT::getVectorVT(MVT::getIntegerVT(SrcEltSize),
DstVT.getVectorElementCount());
Result = DAG.getNode(RISCVISDOpc, DL, InterimIVT, Src, Mask, VL);
// Compare the integer result to 0. The integer should be 0 or 1/-1,
// otherwise the conversion was undefined.
MVT XLenVT = Subtarget.getXLenVT();
SDValue SplatZero = DAG.getConstant(0, DL, XLenVT);
SplatZero = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, InterimIVT,
DAG.getUNDEF(InterimIVT), SplatZero, VL);
Result = DAG.getNode(RISCVISD::SETCC_VL, DL, DstVT,
{Result, SplatZero, DAG.getCondCode(ISD::SETNE),
DAG.getUNDEF(DstVT), Mask, VL});
} else {
MVT InterimIVT = MVT::getVectorVT(MVT::getIntegerVT(SrcEltSize / 2),
DstVT.getVectorElementCount());
Result = DAG.getNode(RISCVISDOpc, DL, InterimIVT, Src, Mask, VL);
while (InterimIVT != DstVT) {
SrcEltSize /= 2;
Src = Result;
InterimIVT = MVT::getVectorVT(MVT::getIntegerVT(SrcEltSize / 2),
DstVT.getVectorElementCount());
Result = DAG.getNode(RISCVISD::TRUNCATE_VECTOR_VL, DL, InterimIVT,
Src, Mask, VL);
}
}
}
}
MVT VT = Op.getSimpleValueType();
if (!VT.isFixedLengthVector())
return Result;
return convertFromScalableVector(VT, Result, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerLogicVPOp(SDValue Op, SelectionDAG &DAG,
unsigned MaskOpc,
unsigned VecOpc) const {
MVT VT = Op.getSimpleValueType();
if (VT.getVectorElementType() != MVT::i1)
return lowerVPOp(Op, DAG, VecOpc, true);
// It is safe to drop mask parameter as masked-off elements are undef.
SDValue Op1 = Op->getOperand(0);
SDValue Op2 = Op->getOperand(1);
SDValue VL = Op->getOperand(3);
MVT ContainerVT = VT;
const bool IsFixed = VT.isFixedLengthVector();
if (IsFixed) {
ContainerVT = getContainerForFixedLengthVector(VT);
Op1 = convertToScalableVector(ContainerVT, Op1, DAG, Subtarget);
Op2 = convertToScalableVector(ContainerVT, Op2, DAG, Subtarget);
}
SDLoc DL(Op);
SDValue Val = DAG.getNode(MaskOpc, DL, ContainerVT, Op1, Op2, VL);
if (!IsFixed)
return Val;
return convertFromScalableVector(VT, Val, DAG, Subtarget);
}
SDValue RISCVTargetLowering::lowerVPStridedLoad(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
MVT VT = Op.getSimpleValueType();
MVT ContainerVT = VT;
if (VT.isFixedLengthVector())
ContainerVT = getContainerForFixedLengthVector(VT);
SDVTList VTs = DAG.getVTList({ContainerVT, MVT::Other});
auto *VPNode = cast<VPStridedLoadSDNode>(Op);
// Check if the mask is known to be all ones
SDValue Mask = VPNode->getMask();
bool IsUnmasked = ISD::isConstantSplatVectorAllOnes(Mask.getNode());
SDValue IntID = DAG.getTargetConstant(IsUnmasked ? Intrinsic::riscv_vlse
: Intrinsic::riscv_vlse_mask,
DL, XLenVT);
SmallVector<SDValue, 8> Ops{VPNode->getChain(), IntID,
DAG.getUNDEF(ContainerVT), VPNode->getBasePtr(),
VPNode->getStride()};
if (!IsUnmasked) {
if (VT.isFixedLengthVector()) {
MVT MaskVT = ContainerVT.changeVectorElementType(MVT::i1);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
Ops.push_back(Mask);
}
Ops.push_back(VPNode->getVectorLength());
if (!IsUnmasked) {
SDValue Policy = DAG.getTargetConstant(RISCVII::TAIL_AGNOSTIC, DL, XLenVT);
Ops.push_back(Policy);
}
SDValue Result =
DAG.getMemIntrinsicNode(ISD::INTRINSIC_W_CHAIN, DL, VTs, Ops,
VPNode->getMemoryVT(), VPNode->getMemOperand());
SDValue Chain = Result.getValue(1);
if (VT.isFixedLengthVector())
Result = convertFromScalableVector(VT, Result, DAG, Subtarget);
return DAG.getMergeValues({Result, Chain}, DL);
}
SDValue RISCVTargetLowering::lowerVPStridedStore(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT XLenVT = Subtarget.getXLenVT();
auto *VPNode = cast<VPStridedStoreSDNode>(Op);
SDValue StoreVal = VPNode->getValue();
MVT VT = StoreVal.getSimpleValueType();
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
StoreVal = convertToScalableVector(ContainerVT, StoreVal, DAG, Subtarget);
}
// Check if the mask is known to be all ones
SDValue Mask = VPNode->getMask();
bool IsUnmasked = ISD::isConstantSplatVectorAllOnes(Mask.getNode());
SDValue IntID = DAG.getTargetConstant(IsUnmasked ? Intrinsic::riscv_vsse
: Intrinsic::riscv_vsse_mask,
DL, XLenVT);
SmallVector<SDValue, 8> Ops{VPNode->getChain(), IntID, StoreVal,
VPNode->getBasePtr(), VPNode->getStride()};
if (!IsUnmasked) {
if (VT.isFixedLengthVector()) {
MVT MaskVT = ContainerVT.changeVectorElementType(MVT::i1);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
Ops.push_back(Mask);
}
Ops.push_back(VPNode->getVectorLength());
return DAG.getMemIntrinsicNode(ISD::INTRINSIC_VOID, DL, VPNode->getVTList(),
Ops, VPNode->getMemoryVT(),
VPNode->getMemOperand());
}
// Custom lower MGATHER/VP_GATHER to a legalized form for RVV. It will then be
// matched to a RVV indexed load. The RVV indexed load instructions only
// support the "unsigned unscaled" addressing mode; indices are implicitly
// zero-extended or truncated to XLEN and are treated as byte offsets. Any
// signed or scaled indexing is extended to the XLEN value type and scaled
// accordingly.
SDValue RISCVTargetLowering::lowerMaskedGather(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT VT = Op.getSimpleValueType();
const auto *MemSD = cast<MemSDNode>(Op.getNode());
EVT MemVT = MemSD->getMemoryVT();
MachineMemOperand *MMO = MemSD->getMemOperand();
SDValue Chain = MemSD->getChain();
SDValue BasePtr = MemSD->getBasePtr();
ISD::LoadExtType LoadExtType;
SDValue Index, Mask, PassThru, VL;
if (auto *VPGN = dyn_cast<VPGatherSDNode>(Op.getNode())) {
Index = VPGN->getIndex();
Mask = VPGN->getMask();
PassThru = DAG.getUNDEF(VT);
VL = VPGN->getVectorLength();
// VP doesn't support extending loads.
LoadExtType = ISD::NON_EXTLOAD;
} else {
// Else it must be a MGATHER.
auto *MGN = cast<MaskedGatherSDNode>(Op.getNode());
Index = MGN->getIndex();
Mask = MGN->getMask();
PassThru = MGN->getPassThru();
LoadExtType = MGN->getExtensionType();
}
MVT IndexVT = Index.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
assert(VT.getVectorElementCount() == IndexVT.getVectorElementCount() &&
"Unexpected VTs!");
assert(BasePtr.getSimpleValueType() == XLenVT && "Unexpected pointer type");
// Targets have to explicitly opt-in for extending vector loads.
assert(LoadExtType == ISD::NON_EXTLOAD &&
"Unexpected extending MGATHER/VP_GATHER");
(void)LoadExtType;
// If the mask is known to be all ones, optimize to an unmasked intrinsic;
// the selection of the masked intrinsics doesn't do this for us.
bool IsUnmasked = ISD::isConstantSplatVectorAllOnes(Mask.getNode());
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
IndexVT = MVT::getVectorVT(IndexVT.getVectorElementType(),
ContainerVT.getVectorElementCount());
Index = convertToScalableVector(IndexVT, Index, DAG, Subtarget);
if (!IsUnmasked) {
MVT MaskVT = getMaskTypeFor(ContainerVT);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
PassThru = convertToScalableVector(ContainerVT, PassThru, DAG, Subtarget);
}
}
if (!VL)
VL = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).second;
if (XLenVT == MVT::i32 && IndexVT.getVectorElementType().bitsGT(XLenVT)) {
IndexVT = IndexVT.changeVectorElementType(XLenVT);
SDValue TrueMask = DAG.getNode(RISCVISD::VMSET_VL, DL, Mask.getValueType(),
VL);
Index = DAG.getNode(RISCVISD::TRUNCATE_VECTOR_VL, DL, IndexVT, Index,
TrueMask, VL);
}
unsigned IntID =
IsUnmasked ? Intrinsic::riscv_vluxei : Intrinsic::riscv_vluxei_mask;
SmallVector<SDValue, 8> Ops{Chain, DAG.getTargetConstant(IntID, DL, XLenVT)};
if (IsUnmasked)
Ops.push_back(DAG.getUNDEF(ContainerVT));
else
Ops.push_back(PassThru);
Ops.push_back(BasePtr);
Ops.push_back(Index);
if (!IsUnmasked)
Ops.push_back(Mask);
Ops.push_back(VL);
if (!IsUnmasked)
Ops.push_back(DAG.getTargetConstant(RISCVII::TAIL_AGNOSTIC, DL, XLenVT));
SDVTList VTs = DAG.getVTList({ContainerVT, MVT::Other});
SDValue Result =
DAG.getMemIntrinsicNode(ISD::INTRINSIC_W_CHAIN, DL, VTs, Ops, MemVT, MMO);
Chain = Result.getValue(1);
if (VT.isFixedLengthVector())
Result = convertFromScalableVector(VT, Result, DAG, Subtarget);
return DAG.getMergeValues({Result, Chain}, DL);
}
// Custom lower MSCATTER/VP_SCATTER to a legalized form for RVV. It will then be
// matched to a RVV indexed store. The RVV indexed store instructions only
// support the "unsigned unscaled" addressing mode; indices are implicitly
// zero-extended or truncated to XLEN and are treated as byte offsets. Any
// signed or scaled indexing is extended to the XLEN value type and scaled
// accordingly.
SDValue RISCVTargetLowering::lowerMaskedScatter(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
const auto *MemSD = cast<MemSDNode>(Op.getNode());
EVT MemVT = MemSD->getMemoryVT();
MachineMemOperand *MMO = MemSD->getMemOperand();
SDValue Chain = MemSD->getChain();
SDValue BasePtr = MemSD->getBasePtr();
bool IsTruncatingStore = false;
SDValue Index, Mask, Val, VL;
if (auto *VPSN = dyn_cast<VPScatterSDNode>(Op.getNode())) {
Index = VPSN->getIndex();
Mask = VPSN->getMask();
Val = VPSN->getValue();
VL = VPSN->getVectorLength();
// VP doesn't support truncating stores.
IsTruncatingStore = false;
} else {
// Else it must be a MSCATTER.
auto *MSN = cast<MaskedScatterSDNode>(Op.getNode());
Index = MSN->getIndex();
Mask = MSN->getMask();
Val = MSN->getValue();
IsTruncatingStore = MSN->isTruncatingStore();
}
MVT VT = Val.getSimpleValueType();
MVT IndexVT = Index.getSimpleValueType();
MVT XLenVT = Subtarget.getXLenVT();
assert(VT.getVectorElementCount() == IndexVT.getVectorElementCount() &&
"Unexpected VTs!");
assert(BasePtr.getSimpleValueType() == XLenVT && "Unexpected pointer type");
// Targets have to explicitly opt-in for extending vector loads and
// truncating vector stores.
assert(!IsTruncatingStore && "Unexpected truncating MSCATTER/VP_SCATTER");
(void)IsTruncatingStore;
// If the mask is known to be all ones, optimize to an unmasked intrinsic;
// the selection of the masked intrinsics doesn't do this for us.
bool IsUnmasked = ISD::isConstantSplatVectorAllOnes(Mask.getNode());
MVT ContainerVT = VT;
if (VT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VT);
IndexVT = MVT::getVectorVT(IndexVT.getVectorElementType(),
ContainerVT.getVectorElementCount());
Index = convertToScalableVector(IndexVT, Index, DAG, Subtarget);
Val = convertToScalableVector(ContainerVT, Val, DAG, Subtarget);
if (!IsUnmasked) {
MVT MaskVT = getMaskTypeFor(ContainerVT);
Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
}
}
if (!VL)
VL = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget).second;
if (XLenVT == MVT::i32 && IndexVT.getVectorElementType().bitsGT(XLenVT)) {
IndexVT = IndexVT.changeVectorElementType(XLenVT);
SDValue TrueMask = DAG.getNode(RISCVISD::VMSET_VL, DL, Mask.getValueType(),
VL);
Index = DAG.getNode(RISCVISD::TRUNCATE_VECTOR_VL, DL, IndexVT, Index,
TrueMask, VL);
}
unsigned IntID =
IsUnmasked ? Intrinsic::riscv_vsoxei : Intrinsic::riscv_vsoxei_mask;
SmallVector<SDValue, 8> Ops{Chain, DAG.getTargetConstant(IntID, DL, XLenVT)};
Ops.push_back(Val);
Ops.push_back(BasePtr);
Ops.push_back(Index);
if (!IsUnmasked)
Ops.push_back(Mask);
Ops.push_back(VL);
return DAG.getMemIntrinsicNode(ISD::INTRINSIC_VOID, DL,
DAG.getVTList(MVT::Other), Ops, MemVT, MMO);
}
SDValue RISCVTargetLowering::lowerGET_ROUNDING(SDValue Op,
SelectionDAG &DAG) const {
const MVT XLenVT = Subtarget.getXLenVT();
SDLoc DL(Op);
SDValue Chain = Op->getOperand(0);
SDValue SysRegNo = DAG.getTargetConstant(
RISCVSysReg::lookupSysRegByName("FRM")->Encoding, DL, XLenVT);
SDVTList VTs = DAG.getVTList(XLenVT, MVT::Other);
SDValue RM = DAG.getNode(RISCVISD::READ_CSR, DL, VTs, Chain, SysRegNo);
// Encoding used for rounding mode in RISC-V differs from that used in
// FLT_ROUNDS. To convert it the RISC-V rounding mode is used as an index in a
// table, which consists of a sequence of 4-bit fields, each representing
// corresponding FLT_ROUNDS mode.
static const int Table =
(int(RoundingMode::NearestTiesToEven) << 4 * RISCVFPRndMode::RNE) |
(int(RoundingMode::TowardZero) << 4 * RISCVFPRndMode::RTZ) |
(int(RoundingMode::TowardNegative) << 4 * RISCVFPRndMode::RDN) |
(int(RoundingMode::TowardPositive) << 4 * RISCVFPRndMode::RUP) |
(int(RoundingMode::NearestTiesToAway) << 4 * RISCVFPRndMode::RMM);
SDValue Shift =
DAG.getNode(ISD::SHL, DL, XLenVT, RM, DAG.getConstant(2, DL, XLenVT));
SDValue Shifted = DAG.getNode(ISD::SRL, DL, XLenVT,
DAG.getConstant(Table, DL, XLenVT), Shift);
SDValue Masked = DAG.getNode(ISD::AND, DL, XLenVT, Shifted,
DAG.getConstant(7, DL, XLenVT));
return DAG.getMergeValues({Masked, Chain}, DL);
}
SDValue RISCVTargetLowering::lowerSET_ROUNDING(SDValue Op,
SelectionDAG &DAG) const {
const MVT XLenVT = Subtarget.getXLenVT();
SDLoc DL(Op);
SDValue Chain = Op->getOperand(0);
SDValue RMValue = Op->getOperand(1);
SDValue SysRegNo = DAG.getTargetConstant(
RISCVSysReg::lookupSysRegByName("FRM")->Encoding, DL, XLenVT);
// Encoding used for rounding mode in RISC-V differs from that used in
// FLT_ROUNDS. To convert it the C rounding mode is used as an index in
// a table, which consists of a sequence of 4-bit fields, each representing
// corresponding RISC-V mode.
static const unsigned Table =
(RISCVFPRndMode::RNE << 4 * int(RoundingMode::NearestTiesToEven)) |
(RISCVFPRndMode::RTZ << 4 * int(RoundingMode::TowardZero)) |
(RISCVFPRndMode::RDN << 4 * int(RoundingMode::TowardNegative)) |
(RISCVFPRndMode::RUP << 4 * int(RoundingMode::TowardPositive)) |
(RISCVFPRndMode::RMM << 4 * int(RoundingMode::NearestTiesToAway));
SDValue Shift = DAG.getNode(ISD::SHL, DL, XLenVT, RMValue,
DAG.getConstant(2, DL, XLenVT));
SDValue Shifted = DAG.getNode(ISD::SRL, DL, XLenVT,
DAG.getConstant(Table, DL, XLenVT), Shift);
RMValue = DAG.getNode(ISD::AND, DL, XLenVT, Shifted,
DAG.getConstant(0x7, DL, XLenVT));
return DAG.getNode(RISCVISD::WRITE_CSR, DL, MVT::Other, Chain, SysRegNo,
RMValue);
}
SDValue RISCVTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
SelectionDAG &DAG) const {
MachineFunction &MF = DAG.getMachineFunction();
bool isRISCV64 = Subtarget.is64Bit();
EVT PtrVT = getPointerTy(DAG.getDataLayout());
int FI = MF.getFrameInfo().CreateFixedObject(isRISCV64 ? 8 : 4, 0, false);
return DAG.getFrameIndex(FI, PtrVT);
}
// Returns the opcode of the target-specific SDNode that implements the 32-bit
// form of the given Opcode.
static RISCVISD::NodeType getRISCVWOpcode(unsigned Opcode) {
switch (Opcode) {
default:
llvm_unreachable("Unexpected opcode");
case ISD::SHL:
return RISCVISD::SLLW;
case ISD::SRA:
return RISCVISD::SRAW;
case ISD::SRL:
return RISCVISD::SRLW;
case ISD::SDIV:
return RISCVISD::DIVW;
case ISD::UDIV:
return RISCVISD::DIVUW;
case ISD::UREM:
return RISCVISD::REMUW;
case ISD::ROTL:
return RISCVISD::ROLW;
case ISD::ROTR:
return RISCVISD::RORW;
}
}
// Converts the given i8/i16/i32 operation to a target-specific SelectionDAG
// node. Because i8/i16/i32 isn't a legal type for RV64, these operations would
// otherwise be promoted to i64, making it difficult to select the
// SLLW/DIVUW/.../*W later one because the fact the operation was originally of
// type i8/i16/i32 is lost.
static SDValue customLegalizeToWOp(SDNode *N, SelectionDAG &DAG,
unsigned ExtOpc = ISD::ANY_EXTEND) {
SDLoc DL(N);
RISCVISD::NodeType WOpcode = getRISCVWOpcode(N->getOpcode());
SDValue NewOp0 = DAG.getNode(ExtOpc, DL, MVT::i64, N->getOperand(0));
SDValue NewOp1 = DAG.getNode(ExtOpc, DL, MVT::i64, N->getOperand(1));
SDValue NewRes = DAG.getNode(WOpcode, DL, MVT::i64, NewOp0, NewOp1);
// ReplaceNodeResults requires we maintain the same type for the return value.
return DAG.getNode(ISD::TRUNCATE, DL, N->getValueType(0), NewRes);
}
// Converts the given 32-bit operation to a i64 operation with signed extension
// semantic to reduce the signed extension instructions.
static SDValue customLegalizeToWOpWithSExt(SDNode *N, SelectionDAG &DAG) {
SDLoc DL(N);
SDValue NewOp0 = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(0));
SDValue NewOp1 = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(1));
SDValue NewWOp = DAG.getNode(N->getOpcode(), DL, MVT::i64, NewOp0, NewOp1);
SDValue NewRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i64, NewWOp,
DAG.getValueType(MVT::i32));
return DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, NewRes);
}
void RISCVTargetLowering::ReplaceNodeResults(SDNode *N,
SmallVectorImpl<SDValue> &Results,
SelectionDAG &DAG) const {
SDLoc DL(N);
switch (N->getOpcode()) {
default:
llvm_unreachable("Don't know how to custom type legalize this operation!");
case ISD::STRICT_FP_TO_SINT:
case ISD::STRICT_FP_TO_UINT:
case ISD::FP_TO_SINT:
case ISD::FP_TO_UINT: {
assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
bool IsStrict = N->isStrictFPOpcode();
bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT ||
N->getOpcode() == ISD::STRICT_FP_TO_SINT;
SDValue Op0 = IsStrict ? N->getOperand(1) : N->getOperand(0);
if (getTypeAction(*DAG.getContext(), Op0.getValueType()) !=
TargetLowering::TypeSoftenFloat) {
if (!isTypeLegal(Op0.getValueType()))
return;
if (IsStrict) {
SDValue Chain = N->getOperand(0);
// In absense of Zfh, promote f16 to f32, then convert.
if (Op0.getValueType() == MVT::f16 && !Subtarget.hasStdExtZfh()) {
Op0 = DAG.getNode(ISD::STRICT_FP_EXTEND, DL, {MVT::f32, MVT::Other},
{Chain, Op0});
Chain = Op0.getValue(1);
}
unsigned Opc = IsSigned ? RISCVISD::STRICT_FCVT_W_RV64
: RISCVISD::STRICT_FCVT_WU_RV64;
SDVTList VTs = DAG.getVTList(MVT::i64, MVT::Other);
SDValue Res = DAG.getNode(
Opc, DL, VTs, Chain, Op0,
DAG.getTargetConstant(RISCVFPRndMode::RTZ, DL, MVT::i64));
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Res));
Results.push_back(Res.getValue(1));
return;
}
// In absense of Zfh, promote f16 to f32, then convert.
if (Op0.getValueType() == MVT::f16 && !Subtarget.hasStdExtZfh())
Op0 = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Op0);
unsigned Opc = IsSigned ? RISCVISD::FCVT_W_RV64 : RISCVISD::FCVT_WU_RV64;
SDValue Res =
DAG.getNode(Opc, DL, MVT::i64, Op0,
DAG.getTargetConstant(RISCVFPRndMode::RTZ, DL, MVT::i64));
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Res));
return;
}
// If the FP type needs to be softened, emit a library call using the 'si'
// version. If we left it to default legalization we'd end up with 'di'. If
// the FP type doesn't need to be softened just let generic type
// legalization promote the result type.
RTLIB::Libcall LC;
if (IsSigned)
LC = RTLIB::getFPTOSINT(Op0.getValueType(), N->getValueType(0));
else
LC = RTLIB::getFPTOUINT(Op0.getValueType(), N->getValueType(0));
MakeLibCallOptions CallOptions;
EVT OpVT = Op0.getValueType();
CallOptions.setTypeListBeforeSoften(OpVT, N->getValueType(0), true);
SDValue Chain = IsStrict ? N->getOperand(0) : SDValue();
SDValue Result;
std::tie(Result, Chain) =
makeLibCall(DAG, LC, N->getValueType(0), Op0, CallOptions, DL, Chain);
Results.push_back(Result);
if (IsStrict)
Results.push_back(Chain);
break;
}
case ISD::LROUND: {
SDValue Op0 = N->getOperand(0);
EVT Op0VT = Op0.getValueType();
if (getTypeAction(*DAG.getContext(), Op0.getValueType()) !=
TargetLowering::TypeSoftenFloat) {
if (!isTypeLegal(Op0VT))
return;
// In absense of Zfh, promote f16 to f32, then convert.
if (Op0.getValueType() == MVT::f16 && !Subtarget.hasStdExtZfh())
Op0 = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Op0);
SDValue Res =
DAG.getNode(RISCVISD::FCVT_W_RV64, DL, MVT::i64, Op0,
DAG.getTargetConstant(RISCVFPRndMode::RMM, DL, MVT::i64));
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Res));
return;
}
// If the FP type needs to be softened, emit a library call to lround. We'll
// need to truncate the result. We assume any value that doesn't fit in i32
// is allowed to return an unspecified value.
RTLIB::Libcall LC =
Op0.getValueType() == MVT::f64 ? RTLIB::LROUND_F64 : RTLIB::LROUND_F32;
MakeLibCallOptions CallOptions;
EVT OpVT = Op0.getValueType();
CallOptions.setTypeListBeforeSoften(OpVT, MVT::i64, true);
SDValue Result = makeLibCall(DAG, LC, MVT::i64, Op0, CallOptions, DL).first;
Result = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Result);
Results.push_back(Result);
break;
}
case ISD::READCYCLECOUNTER: {
assert(!Subtarget.is64Bit() &&
"READCYCLECOUNTER only has custom type legalization on riscv32");
SDVTList VTs = DAG.getVTList(MVT::i32, MVT::i32, MVT::Other);
SDValue RCW =
DAG.getNode(RISCVISD::READ_CYCLE_WIDE, DL, VTs, N->getOperand(0));
Results.push_back(
DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, RCW, RCW.getValue(1)));
Results.push_back(RCW.getValue(2));
break;
}
case ISD::LOAD: {
if (!ISD::isNON_EXTLoad(N))
return;
// Use a SEXTLOAD instead of the default EXTLOAD. Similar to the
// sext_inreg we emit for ADD/SUB/MUL/SLLI.
LoadSDNode *Ld = cast<LoadSDNode>(N);
SDLoc dl(N);
SDValue Res = DAG.getExtLoad(ISD::SEXTLOAD, dl, MVT::i64, Ld->getChain(),
Ld->getBasePtr(), Ld->getMemoryVT(),
Ld->getMemOperand());
Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Res));
Results.push_back(Res.getValue(1));
return;
}
case ISD::MUL: {
unsigned Size = N->getSimpleValueType(0).getSizeInBits();
unsigned XLen = Subtarget.getXLen();
// This multiply needs to be expanded, try to use MULHSU+MUL if possible.
if (Size > XLen) {
assert(Size == (XLen * 2) && "Unexpected custom legalisation");
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
APInt HighMask = APInt::getHighBitsSet(Size, XLen);
bool LHSIsU = DAG.MaskedValueIsZero(LHS, HighMask);
bool RHSIsU = DAG.MaskedValueIsZero(RHS, HighMask);
// We need exactly one side to be unsigned.
if (LHSIsU == RHSIsU)
return;
auto MakeMULPair = [&](SDValue S, SDValue U) {
MVT XLenVT = Subtarget.getXLenVT();
S = DAG.getNode(ISD::TRUNCATE, DL, XLenVT, S);
U = DAG.getNode(ISD::TRUNCATE, DL, XLenVT, U);
SDValue Lo = DAG.getNode(ISD::MUL, DL, XLenVT, S, U);
SDValue Hi = DAG.getNode(RISCVISD::MULHSU, DL, XLenVT, S, U);
return DAG.getNode(ISD::BUILD_PAIR, DL, N->getValueType(0), Lo, Hi);
};
bool LHSIsS = DAG.ComputeNumSignBits(LHS) > XLen;
bool RHSIsS = DAG.ComputeNumSignBits(RHS) > XLen;
// The other operand should be signed, but still prefer MULH when
// possible.
if (RHSIsU && LHSIsS && !RHSIsS)
Results.push_back(MakeMULPair(LHS, RHS));
else if (LHSIsU && RHSIsS && !LHSIsS)
Results.push_back(MakeMULPair(RHS, LHS));
return;
}
[[fallthrough]];
}
case ISD::ADD:
case ISD::SUB:
assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
Results.push_back(customLegalizeToWOpWithSExt(N, DAG));
break;
case ISD::SHL:
case ISD::SRA:
case ISD::SRL:
assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
if (N->getOperand(1).getOpcode() != ISD::Constant) {
// If we can use a BSET instruction, allow default promotion to apply.
if (N->getOpcode() == ISD::SHL && Subtarget.hasStdExtZbs() &&
isOneConstant(N->getOperand(0)))
break;
Results.push_back(customLegalizeToWOp(N, DAG));
break;
}
// Custom legalize ISD::SHL by placing a SIGN_EXTEND_INREG after. This is
// similar to customLegalizeToWOpWithSExt, but we must zero_extend the
// shift amount.
if (N->getOpcode() == ISD::SHL) {
SDLoc DL(N);
SDValue NewOp0 =
DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(0));
SDValue NewOp1 =
DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, N->getOperand(1));
SDValue NewWOp = DAG.getNode(ISD::SHL, DL, MVT::i64, NewOp0, NewOp1);
SDValue NewRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i64, NewWOp,
DAG.getValueType(MVT::i32));
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, NewRes));
}
break;
case ISD::ROTL:
case ISD::ROTR:
assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
Results.push_back(customLegalizeToWOp(N, DAG));
break;
case ISD::CTTZ:
case ISD::CTTZ_ZERO_UNDEF:
case ISD::CTLZ:
case ISD::CTLZ_ZERO_UNDEF: {
assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
SDValue NewOp0 =
DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(0));
bool IsCTZ =
N->getOpcode() == ISD::CTTZ || N->getOpcode() == ISD::CTTZ_ZERO_UNDEF;
unsigned Opc = IsCTZ ? RISCVISD::CTZW : RISCVISD::CLZW;
SDValue Res = DAG.getNode(Opc, DL, MVT::i64, NewOp0);
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Res));
return;
}
case ISD::SDIV:
case ISD::UDIV:
case ISD::UREM: {
MVT VT = N->getSimpleValueType(0);
assert((VT == MVT::i8 || VT == MVT::i16 || VT == MVT::i32) &&
Subtarget.is64Bit() && Subtarget.hasStdExtM() &&
"Unexpected custom legalisation");
// Don't promote division/remainder by constant since we should expand those
// to multiply by magic constant.
AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes();
if (N->getOperand(1).getOpcode() == ISD::Constant &&
!isIntDivCheap(N->getValueType(0), Attr))
return;
// If the input is i32, use ANY_EXTEND since the W instructions don't read
// the upper 32 bits. For other types we need to sign or zero extend
// based on the opcode.
unsigned ExtOpc = ISD::ANY_EXTEND;
if (VT != MVT::i32)
ExtOpc = N->getOpcode() == ISD::SDIV ? ISD::SIGN_EXTEND
: ISD::ZERO_EXTEND;
Results.push_back(customLegalizeToWOp(N, DAG, ExtOpc));
break;
}
case ISD::UADDO:
case ISD::USUBO: {
assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
bool IsAdd = N->getOpcode() == ISD::UADDO;
// Create an ADDW or SUBW.
SDValue LHS = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(0));
SDValue RHS = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(1));
SDValue Res =
DAG.getNode(IsAdd ? ISD::ADD : ISD::SUB, DL, MVT::i64, LHS, RHS);
Res = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i64, Res,
DAG.getValueType(MVT::i32));
SDValue Overflow;
if (IsAdd && isOneConstant(RHS)) {
// Special case uaddo X, 1 overflowed if the addition result is 0.
// The general case (X + C) < C is not necessarily beneficial. Although we
// reduce the live range of X, we may introduce the materialization of
// constant C, especially when the setcc result is used by branch. We have
// no compare with constant and branch instructions.
Overflow = DAG.getSetCC(DL, N->getValueType(1), Res,
DAG.getConstant(0, DL, MVT::i64), ISD::SETEQ);
} else if (IsAdd && isAllOnesConstant(RHS)) {
// Special case uaddo X, -1 overflowed if X != 0.
Overflow = DAG.getSetCC(DL, N->getValueType(1), N->getOperand(0),
DAG.getConstant(0, DL, MVT::i32), ISD::SETNE);
} else {
// Sign extend the LHS and perform an unsigned compare with the ADDW
// result. Since the inputs are sign extended from i32, this is equivalent
// to comparing the lower 32 bits.
LHS = DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i64, N->getOperand(0));
Overflow = DAG.getSetCC(DL, N->getValueType(1), Res, LHS,
IsAdd ? ISD::SETULT : ISD::SETUGT);
}
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Res));
Results.push_back(Overflow);
return;
}
case ISD::UADDSAT:
case ISD::USUBSAT: {
assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
if (Subtarget.hasStdExtZbb()) {
// With Zbb we can sign extend and let LegalizeDAG use minu/maxu. Using
// sign extend allows overflow of the lower 32 bits to be detected on
// the promoted size.
SDValue LHS =
DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i64, N->getOperand(0));
SDValue RHS =
DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i64, N->getOperand(1));
SDValue Res = DAG.getNode(N->getOpcode(), DL, MVT::i64, LHS, RHS);
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Res));
return;
}
// Without Zbb, expand to UADDO/USUBO+select which will trigger our custom
// promotion for UADDO/USUBO.
Results.push_back(expandAddSubSat(N, DAG));
return;
}
case ISD::ABS: {
assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
"Unexpected custom legalisation");
if (Subtarget.hasStdExtZbb()) {
// Emit a special ABSW node that will be expanded to NEGW+MAX at isel.
// This allows us to remember that the result is sign extended. Expanding
// to NEGW+MAX here requires a Freeze which breaks ComputeNumSignBits.
SDValue Src = DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i64,
N->getOperand(0));
SDValue Abs = DAG.getNode(RISCVISD::ABSW, DL, MVT::i64, Src);
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Abs));
return;
}
// Expand abs to Y = (sraiw X, 31); subw(xor(X, Y), Y)
SDValue Src = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(0));
// Freeze the source so we can increase it's use count.
Src = DAG.getFreeze(Src);
// Copy sign bit to all bits using the sraiw pattern.
SDValue SignFill = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i64, Src,
DAG.getValueType(MVT::i32));
SignFill = DAG.getNode(ISD::SRA, DL, MVT::i64, SignFill,
DAG.getConstant(31, DL, MVT::i64));
SDValue NewRes = DAG.getNode(ISD::XOR, DL, MVT::i64, Src, SignFill);
NewRes = DAG.getNode(ISD::SUB, DL, MVT::i64, NewRes, SignFill);
// NOTE: The result is only required to be anyextended, but sext is
// consistent with type legalization of sub.
NewRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i64, NewRes,
DAG.getValueType(MVT::i32));
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, NewRes));
return;
}
case ISD::BITCAST: {
EVT VT = N->getValueType(0);
assert(VT.isInteger() && !VT.isVector() && "Unexpected VT!");
SDValue Op0 = N->getOperand(0);
EVT Op0VT = Op0.getValueType();
MVT XLenVT = Subtarget.getXLenVT();
if (VT == MVT::i16 && Op0VT == MVT::f16 &&
Subtarget.hasStdExtZfhOrZfhmin()) {
SDValue FPConv = DAG.getNode(RISCVISD::FMV_X_ANYEXTH, DL, XLenVT, Op0);
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i16, FPConv));
} else if (VT == MVT::i32 && Op0VT == MVT::f32 && Subtarget.is64Bit() &&
Subtarget.hasStdExtF()) {
SDValue FPConv =
DAG.getNode(RISCVISD::FMV_X_ANYEXTW_RV64, DL, MVT::i64, Op0);
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, FPConv));
} else if (VT == MVT::i64 && Op0VT == MVT::f64 && XLenVT == MVT::i32 &&
Subtarget.hasStdExtZfa()) {
SDValue NewReg = DAG.getNode(RISCVISD::SplitF64, DL,
DAG.getVTList(MVT::i32, MVT::i32), Op0);
SDValue RetReg = DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64,
NewReg.getValue(0), NewReg.getValue(1));
Results.push_back(RetReg);
} else if (!VT.isVector() && Op0VT.isFixedLengthVector() &&
isTypeLegal(Op0VT)) {
// Custom-legalize bitcasts from fixed-length vector types to illegal
// scalar types in order to improve codegen. Bitcast the vector to a
// one-element vector type whose element type is the same as the result
// type, and extract the first element.
EVT BVT = EVT::getVectorVT(*DAG.getContext(), VT, 1);
if (isTypeLegal(BVT)) {
SDValue BVec = DAG.getBitcast(BVT, Op0);
Results.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, BVec,
DAG.getConstant(0, DL, XLenVT)));
}
}
break;
}
case RISCVISD::BREV8: {
MVT VT = N->getSimpleValueType(0);
MVT XLenVT = Subtarget.getXLenVT();
assert((VT == MVT::i16 || (VT == MVT::i32 && Subtarget.is64Bit())) &&
"Unexpected custom legalisation");
assert(Subtarget.hasStdExtZbkb() && "Unexpected extension");
SDValue NewOp = DAG.getNode(ISD::ANY_EXTEND, DL, XLenVT, N->getOperand(0));
SDValue NewRes = DAG.getNode(N->getOpcode(), DL, XLenVT, NewOp);
// ReplaceNodeResults requires we maintain the same type for the return
// value.
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, VT, NewRes));
break;
}
case ISD::EXTRACT_VECTOR_ELT: {
// Custom-legalize an EXTRACT_VECTOR_ELT where XLEN<SEW, as the SEW element
// type is illegal (currently only vXi64 RV32).
// With vmv.x.s, when SEW > XLEN, only the least-significant XLEN bits are
// transferred to the destination register. We issue two of these from the
// upper- and lower- halves of the SEW-bit vector element, slid down to the
// first element.
SDValue Vec = N->getOperand(0);
SDValue Idx = N->getOperand(1);
// The vector type hasn't been legalized yet so we can't issue target
// specific nodes if it needs legalization.
// FIXME: We would manually legalize if it's important.
if (!isTypeLegal(Vec.getValueType()))
return;
MVT VecVT = Vec.getSimpleValueType();
assert(!Subtarget.is64Bit() && N->getValueType(0) == MVT::i64 &&
VecVT.getVectorElementType() == MVT::i64 &&
"Unexpected EXTRACT_VECTOR_ELT legalization");
// If this is a fixed vector, we need to convert it to a scalable vector.
MVT ContainerVT = VecVT;
if (VecVT.isFixedLengthVector()) {
ContainerVT = getContainerForFixedLengthVector(VecVT);
Vec = convertToScalableVector(ContainerVT, Vec, DAG, Subtarget);
}
MVT XLenVT = Subtarget.getXLenVT();
// Use a VL of 1 to avoid processing more elements than we need.
auto [Mask, VL] = getDefaultVLOps(1, ContainerVT, DL, DAG, Subtarget);
// Unless the index is known to be 0, we must slide the vector down to get
// the desired element into index 0.
if (!isNullConstant(Idx)) {
Vec = getVSlidedown(DAG, Subtarget, DL, ContainerVT,
DAG.getUNDEF(ContainerVT), Vec, Idx, Mask, VL);
}
// Extract the lower XLEN bits of the correct vector element.
SDValue EltLo = DAG.getNode(RISCVISD::VMV_X_S, DL, XLenVT, Vec);
// To extract the upper XLEN bits of the vector element, shift the first
// element right by 32 bits and re-extract the lower XLEN bits.
SDValue ThirtyTwoV = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ContainerVT,
DAG.getUNDEF(ContainerVT),
DAG.getConstant(32, DL, XLenVT), VL);
SDValue LShr32 =
DAG.getNode(RISCVISD::SRL_VL, DL, ContainerVT, Vec, ThirtyTwoV,
DAG.getUNDEF(ContainerVT), Mask, VL);
SDValue EltHi = DAG.getNode(RISCVISD::VMV_X_S, DL, XLenVT, LShr32);
Results.push_back(DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, EltLo, EltHi));
break;
}
case ISD::INTRINSIC_WO_CHAIN: {
unsigned IntNo = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
switch (IntNo) {
default:
llvm_unreachable(
"Don't know how to custom type legalize this intrinsic!");
case Intrinsic::riscv_orc_b: {
SDValue NewOp =
DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(1));
SDValue Res = DAG.getNode(RISCVISD::ORC_B, DL, MVT::i64, NewOp);
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Res));
return;
}
case Intrinsic::riscv_vmv_x_s: {
EVT VT = N->getValueType(0);
MVT XLenVT = Subtarget.getXLenVT();
if (VT.bitsLT(XLenVT)) {
// Simple case just extract using vmv.x.s and truncate.
SDValue Extract = DAG.getNode(RISCVISD::VMV_X_S, DL,
Subtarget.getXLenVT(), N->getOperand(1));
Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, VT, Extract));
return;
}
assert(VT == MVT::i64 && !Subtarget.is64Bit() &&
"Unexpected custom legalization");
// We need to do the move in two steps.
SDValue Vec = N->getOperand(1);
MVT VecVT = Vec.getSimpleValueType();
// First extract the lower XLEN bits of the element.
SDValue EltLo = DAG.getNode(RISCVISD::VMV_X_S, DL, XLenVT, Vec);
// To extract the upper XLEN bits of the vector element, shift the first
// element right by 32 bits and re-extract the lower XLEN bits.
auto [Mask, VL] = getDefaultVLOps(1, VecVT, DL, DAG, Subtarget);
SDValue ThirtyTwoV =
DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VecVT, DAG.getUNDEF(VecVT),
DAG.getConstant(32, DL, XLenVT), VL);
SDValue LShr32 = DAG.getNode(RISCVISD::SRL_VL, DL, VecVT, Vec, ThirtyTwoV,
DAG.getUNDEF(VecVT), Mask, VL);
SDValue EltHi = DAG.getNode(RISCVISD::VMV_X_S, DL, XLenVT, LShr32);
Results.push_back(
DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, EltLo, EltHi));
break;
}
}
break;
}
case ISD::VECREDUCE_ADD:
case ISD::VECREDUCE_AND:
case ISD::VECREDUCE_OR:
case ISD::VECREDUCE_XOR:
case ISD::VECREDUCE_SMAX:
case ISD::VECREDUCE_UMAX:
case ISD::VECREDUCE_SMIN:
case ISD::VECREDUCE_UMIN:
if (SDValue V = lowerVECREDUCE(SDValue(N, 0), DAG))
Results.push_back(V);
break;
case ISD::VP_REDUCE_ADD:
case ISD::VP_REDUCE_AND:
case ISD::VP_REDUCE_OR:
case ISD::VP_REDUCE_XOR:
case ISD::VP_REDUCE_SMAX:
case ISD::VP_REDUCE_UMAX:
case ISD::VP_REDUCE_SMIN:
case ISD::VP_REDUCE_UMIN:
if (SDValue V = lowerVPREDUCE(SDValue(N, 0), DAG))
Results.push_back(V);
break;
case ISD::GET_ROUNDING: {
SDVTList VTs = DAG.getVTList(Subtarget.getXLenVT(), MVT::Other);
SDValue Res = DAG.getNode(ISD::GET_ROUNDING, DL, VTs, N->getOperand(0));
Results.push_back(Res.getValue(0));
Results.push_back(Res.getValue(1));
break;
}
}
}
// Try to fold (<bop> x, (reduction.<bop> vec, start))
static SDValue combineBinOpToReduce(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
auto BinOpToRVVReduce = [](unsigned Opc) {
switch (Opc) {
default:
llvm_unreachable("Unhandled binary to transfrom reduction");
case ISD::ADD:
return RISCVISD::VECREDUCE_ADD_VL;
case ISD::UMAX:
return RISCVISD::VECREDUCE_UMAX_VL;
case ISD::SMAX:
return RISCVISD::VECREDUCE_SMAX_VL;
case ISD::UMIN:
return RISCVISD::VECREDUCE_UMIN_VL;
case ISD::SMIN:
return RISCVISD::VECREDUCE_SMIN_VL;
case ISD::AND:
return RISCVISD::VECREDUCE_AND_VL;
case ISD::OR:
return RISCVISD::VECREDUCE_OR_VL;
case ISD::XOR:
return RISCVISD::VECREDUCE_XOR_VL;
case ISD::FADD:
return RISCVISD::VECREDUCE_FADD_VL;
case ISD::FMAXNUM:
return RISCVISD::VECREDUCE_FMAX_VL;
case ISD::FMINNUM:
return RISCVISD::VECREDUCE_FMIN_VL;
}
};
auto IsReduction = [&BinOpToRVVReduce](SDValue V, unsigned Opc) {
return V.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
isNullConstant(V.getOperand(1)) &&
V.getOperand(0).getOpcode() == BinOpToRVVReduce(Opc);
};
unsigned Opc = N->getOpcode();
unsigned ReduceIdx;
if (IsReduction(N->getOperand(0), Opc))
ReduceIdx = 0;
else if (IsReduction(N->getOperand(1), Opc))
ReduceIdx = 1;
else
return SDValue();
// Skip if FADD disallows reassociation but the combiner needs.
if (Opc == ISD::FADD && !N->getFlags().hasAllowReassociation())
return SDValue();
SDValue Extract = N->getOperand(ReduceIdx);
SDValue Reduce = Extract.getOperand(0);
if (!Reduce.hasOneUse())
return SDValue();
SDValue ScalarV = Reduce.getOperand(2);
EVT ScalarVT = ScalarV.getValueType();
if (ScalarV.getOpcode() == ISD::INSERT_SUBVECTOR &&
ScalarV.getOperand(0)->isUndef())
ScalarV = ScalarV.getOperand(1);
// Make sure that ScalarV is a splat with VL=1.
if (ScalarV.getOpcode() != RISCVISD::VFMV_S_F_VL &&
ScalarV.getOpcode() != RISCVISD::VMV_S_X_VL &&
ScalarV.getOpcode() != RISCVISD::VMV_V_X_VL)
return SDValue();
if (!hasNonZeroAVL(ScalarV.getOperand(2)))
return SDValue();
// Check the scalar of ScalarV is neutral element
// TODO: Deal with value other than neutral element.
if (!isNeutralConstant(N->getOpcode(), N->getFlags(), ScalarV.getOperand(1),
0))
return SDValue();
if (!ScalarV.hasOneUse())
return SDValue();
SDValue NewStart = N->getOperand(1 - ReduceIdx);
SDLoc DL(N);
SDValue NewScalarV =
lowerScalarInsert(NewStart, ScalarV.getOperand(2),
ScalarV.getSimpleValueType(), DL, DAG, Subtarget);
// If we looked through an INSERT_SUBVECTOR we need to restore it.
if (ScalarVT != ScalarV.getValueType())
NewScalarV =
DAG.getNode(ISD::INSERT_SUBVECTOR, DL, ScalarVT, DAG.getUNDEF(ScalarVT),
NewScalarV, DAG.getConstant(0, DL, Subtarget.getXLenVT()));
SDValue Ops[] = {Reduce.getOperand(0), Reduce.getOperand(1),
NewScalarV, Reduce.getOperand(3),
Reduce.getOperand(4), Reduce.getOperand(5)};
SDValue NewReduce =
DAG.getNode(Reduce.getOpcode(), DL, Reduce.getValueType(), Ops);
return DAG.getNode(Extract.getOpcode(), DL, Extract.getValueType(), NewReduce,
Extract.getOperand(1));
}
// Optimize (add (shl x, c0), (shl y, c1)) ->
// (SLLI (SH*ADD x, y), c0), if c1-c0 equals to [1|2|3].
static SDValue transformAddShlImm(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
// Perform this optimization only in the zba extension.
if (!Subtarget.hasStdExtZba())
return SDValue();
// Skip for vector types and larger types.
EVT VT = N->getValueType(0);
if (VT.isVector() || VT.getSizeInBits() > Subtarget.getXLen())
return SDValue();
// The two operand nodes must be SHL and have no other use.
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
if (N0->getOpcode() != ISD::SHL || N1->getOpcode() != ISD::SHL ||
!N0->hasOneUse() || !N1->hasOneUse())
return SDValue();
// Check c0 and c1.
auto *N0C = dyn_cast<ConstantSDNode>(N0->getOperand(1));
auto *N1C = dyn_cast<ConstantSDNode>(N1->getOperand(1));
if (!N0C || !N1C)
return SDValue();
int64_t C0 = N0C->getSExtValue();
int64_t C1 = N1C->getSExtValue();
if (C0 <= 0 || C1 <= 0)
return SDValue();
// Skip if SH1ADD/SH2ADD/SH3ADD are not applicable.
int64_t Bits = std::min(C0, C1);
int64_t Diff = std::abs(C0 - C1);
if (Diff != 1 && Diff != 2 && Diff != 3)
return SDValue();
// Build nodes.
SDLoc DL(N);
SDValue NS = (C0 < C1) ? N0->getOperand(0) : N1->getOperand(0);
SDValue NL = (C0 > C1) ? N0->getOperand(0) : N1->getOperand(0);
SDValue NA0 =
DAG.getNode(ISD::SHL, DL, VT, NL, DAG.getConstant(Diff, DL, VT));
SDValue NA1 = DAG.getNode(ISD::ADD, DL, VT, NA0, NS);
return DAG.getNode(ISD::SHL, DL, VT, NA1, DAG.getConstant(Bits, DL, VT));
}
// Combine a constant select operand into its use:
//
// (and (select cond, -1, c), x)
// -> (select cond, x, (and x, c)) [AllOnes=1]
// (or (select cond, 0, c), x)
// -> (select cond, x, (or x, c)) [AllOnes=0]
// (xor (select cond, 0, c), x)
// -> (select cond, x, (xor x, c)) [AllOnes=0]
// (add (select cond, 0, c), x)
// -> (select cond, x, (add x, c)) [AllOnes=0]
// (sub x, (select cond, 0, c))
// -> (select cond, x, (sub x, c)) [AllOnes=0]
static SDValue combineSelectAndUse(SDNode *N, SDValue Slct, SDValue OtherOp,
SelectionDAG &DAG, bool AllOnes,
const RISCVSubtarget &Subtarget) {
EVT VT = N->getValueType(0);
// Skip vectors.
if (VT.isVector())
return SDValue();
if (!Subtarget.hasShortForwardBranchOpt() ||
(Slct.getOpcode() != ISD::SELECT &&
Slct.getOpcode() != RISCVISD::SELECT_CC) ||
!Slct.hasOneUse())
return SDValue();
auto isZeroOrAllOnes = [](SDValue N, bool AllOnes) {
return AllOnes ? isAllOnesConstant(N) : isNullConstant(N);
};
bool SwapSelectOps;
unsigned OpOffset = Slct.getOpcode() == RISCVISD::SELECT_CC ? 2 : 0;
SDValue TrueVal = Slct.getOperand(1 + OpOffset);
SDValue FalseVal = Slct.getOperand(2 + OpOffset);
SDValue NonConstantVal;
if (isZeroOrAllOnes(TrueVal, AllOnes)) {
SwapSelectOps = false;
NonConstantVal = FalseVal;
} else if (isZeroOrAllOnes(FalseVal, AllOnes)) {
SwapSelectOps = true;
NonConstantVal = TrueVal;
} else
return SDValue();
// Slct is now know to be the desired identity constant when CC is true.
TrueVal = OtherOp;
FalseVal = DAG.getNode(N->getOpcode(), SDLoc(N), VT, OtherOp, NonConstantVal);
// Unless SwapSelectOps says the condition should be false.
if (SwapSelectOps)
std::swap(TrueVal, FalseVal);
if (Slct.getOpcode() == RISCVISD::SELECT_CC)
return DAG.getNode(RISCVISD::SELECT_CC, SDLoc(N), VT,
{Slct.getOperand(0), Slct.getOperand(1),
Slct.getOperand(2), TrueVal, FalseVal});
return DAG.getNode(ISD::SELECT, SDLoc(N), VT,
{Slct.getOperand(0), TrueVal, FalseVal});
}
// Attempt combineSelectAndUse on each operand of a commutative operator N.
static SDValue combineSelectAndUseCommutative(SDNode *N, SelectionDAG &DAG,
bool AllOnes,
const RISCVSubtarget &Subtarget) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
if (SDValue Result = combineSelectAndUse(N, N0, N1, DAG, AllOnes, Subtarget))
return Result;
if (SDValue Result = combineSelectAndUse(N, N1, N0, DAG, AllOnes, Subtarget))
return Result;
return SDValue();
}
// Transform (add (mul x, c0), c1) ->
// (add (mul (add x, c1/c0), c0), c1%c0).
// if c1/c0 and c1%c0 are simm12, while c1 is not. A special corner case
// that should be excluded is when c0*(c1/c0) is simm12, which will lead
// to an infinite loop in DAGCombine if transformed.
// Or transform (add (mul x, c0), c1) ->
// (add (mul (add x, c1/c0+1), c0), c1%c0-c0),
// if c1/c0+1 and c1%c0-c0 are simm12, while c1 is not. A special corner
// case that should be excluded is when c0*(c1/c0+1) is simm12, which will
// lead to an infinite loop in DAGCombine if transformed.
// Or transform (add (mul x, c0), c1) ->
// (add (mul (add x, c1/c0-1), c0), c1%c0+c0),
// if c1/c0-1 and c1%c0+c0 are simm12, while c1 is not. A special corner
// case that should be excluded is when c0*(c1/c0-1) is simm12, which will
// lead to an infinite loop in DAGCombine if transformed.
// Or transform (add (mul x, c0), c1) ->
// (mul (add x, c1/c0), c0).
// if c1%c0 is zero, and c1/c0 is simm12 while c1 is not.
static SDValue transformAddImmMulImm(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
// Skip for vector types and larger types.
EVT VT = N->getValueType(0);
if (VT.isVector() || VT.getSizeInBits() > Subtarget.getXLen())
return SDValue();
// The first operand node must be a MUL and has no other use.
SDValue N0 = N->getOperand(0);
if (!N0->hasOneUse() || N0->getOpcode() != ISD::MUL)
return SDValue();
// Check if c0 and c1 match above conditions.
auto *N0C = dyn_cast<ConstantSDNode>(N0->getOperand(1));
auto *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1));
if (!N0C || !N1C)
return SDValue();
// If N0C has multiple uses it's possible one of the cases in
// DAGCombiner::isMulAddWithConstProfitable will be true, which would result
// in an infinite loop.
if (!N0C->hasOneUse())
return SDValue();
int64_t C0 = N0C->getSExtValue();
int64_t C1 = N1C->getSExtValue();
int64_t CA, CB;
if (C0 == -1 || C0 == 0 || C0 == 1 || isInt<12>(C1))
return SDValue();
// Search for proper CA (non-zero) and CB that both are simm12.
if ((C1 / C0) != 0 && isInt<12>(C1 / C0) && isInt<12>(C1 % C0) &&
!isInt<12>(C0 * (C1 / C0))) {
CA = C1 / C0;
CB = C1 % C0;
} else if ((C1 / C0 + 1) != 0 && isInt<12>(C1 / C0 + 1) &&
isInt<12>(C1 % C0 - C0) && !isInt<12>(C0 * (C1 / C0 + 1))) {
CA = C1 / C0 + 1;
CB = C1 % C0 - C0;
} else if ((C1 / C0 - 1) != 0 && isInt<12>(C1 / C0 - 1) &&
isInt<12>(C1 % C0 + C0) && !isInt<12>(C0 * (C1 / C0 - 1))) {
CA = C1 / C0 - 1;
CB = C1 % C0 + C0;
} else
return SDValue();
// Build new nodes (add (mul (add x, c1/c0), c0), c1%c0).
SDLoc DL(N);
SDValue New0 = DAG.getNode(ISD::ADD, DL, VT, N0->getOperand(0),
DAG.getConstant(CA, DL, VT));
SDValue New1 =
DAG.getNode(ISD::MUL, DL, VT, New0, DAG.getConstant(C0, DL, VT));
return DAG.getNode(ISD::ADD, DL, VT, New1, DAG.getConstant(CB, DL, VT));
}
static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
if (SDValue V = transformAddImmMulImm(N, DAG, Subtarget))
return V;
if (SDValue V = transformAddShlImm(N, DAG, Subtarget))
return V;
if (SDValue V = combineBinOpToReduce(N, DAG, Subtarget))
return V;
// fold (add (select lhs, rhs, cc, 0, y), x) ->
// (select lhs, rhs, cc, x, (add x, y))
return combineSelectAndUseCommutative(N, DAG, /*AllOnes*/ false, Subtarget);
}
// Try to turn a sub boolean RHS and constant LHS into an addi.
static SDValue combineSubOfBoolean(SDNode *N, SelectionDAG &DAG) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
SDLoc DL(N);
// Require a constant LHS.
auto *N0C = dyn_cast<ConstantSDNode>(N0);
if (!N0C)
return SDValue();
// All our optimizations involve subtracting 1 from the immediate and forming
// an ADDI. Make sure the new immediate is valid for an ADDI.
APInt ImmValMinus1 = N0C->getAPIntValue() - 1;
if (!ImmValMinus1.isSignedIntN(12))
return SDValue();
SDValue NewLHS;
if (N1.getOpcode() == ISD::SETCC && N1.hasOneUse()) {
// (sub constant, (setcc x, y, eq/neq)) ->
// (add (setcc x, y, neq/eq), constant - 1)
ISD::CondCode CCVal = cast<CondCodeSDNode>(N1.getOperand(2))->get();
EVT SetCCOpVT = N1.getOperand(0).getValueType();
if (!isIntEqualitySetCC(CCVal) || !SetCCOpVT.isInteger())
return SDValue();
CCVal = ISD::getSetCCInverse(CCVal, SetCCOpVT);
NewLHS =
DAG.getSetCC(SDLoc(N1), VT, N1.getOperand(0), N1.getOperand(1), CCVal);
} else if (N1.getOpcode() == ISD::XOR && isOneConstant(N1.getOperand(1)) &&
N1.getOperand(0).getOpcode() == ISD::SETCC) {
// (sub C, (xor (setcc), 1)) -> (add (setcc), C-1).
// Since setcc returns a bool the xor is equivalent to 1-setcc.
NewLHS = N1.getOperand(0);
} else
return SDValue();
SDValue NewRHS = DAG.getConstant(ImmValMinus1, DL, VT);
return DAG.getNode(ISD::ADD, DL, VT, NewLHS, NewRHS);
}
static SDValue performSUBCombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
if (SDValue V = combineSubOfBoolean(N, DAG))
return V;
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
// fold (sub 0, (setcc x, 0, setlt)) -> (sra x, xlen - 1)
if (isNullConstant(N0) && N1.getOpcode() == ISD::SETCC && N1.hasOneUse() &&
isNullConstant(N1.getOperand(1))) {
ISD::CondCode CCVal = cast<CondCodeSDNode>(N1.getOperand(2))->get();
if (CCVal == ISD::SETLT) {
EVT VT = N->getValueType(0);
SDLoc DL(N);
unsigned ShAmt = N0.getValueSizeInBits() - 1;
return DAG.getNode(ISD::SRA, DL, VT, N1.getOperand(0),
DAG.getConstant(ShAmt, DL, VT));
}
}
// fold (sub x, (select lhs, rhs, cc, 0, y)) ->
// (select lhs, rhs, cc, x, (sub x, y))
return combineSelectAndUse(N, N1, N0, DAG, /*AllOnes*/ false, Subtarget);
}
// Apply DeMorgan's law to (and/or (xor X, 1), (xor Y, 1)) if X and Y are 0/1.
// Legalizing setcc can introduce xors like this. Doing this transform reduces
// the number of xors and may allow the xor to fold into a branch condition.
static SDValue combineDeMorganOfBoolean(SDNode *N, SelectionDAG &DAG) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
bool IsAnd = N->getOpcode() == ISD::AND;
if (N0.getOpcode() != ISD::XOR || N1.getOpcode() != ISD::XOR)
return SDValue();
if (!N0.hasOneUse() || !N1.hasOneUse())
return SDValue();
SDValue N01 = N0.getOperand(1);
SDValue N11 = N1.getOperand(1);
// For AND, SimplifyDemandedBits may have turned one of the (xor X, 1) into
// (xor X, -1) based on the upper bits of the other operand being 0. If the
// operation is And, allow one of the Xors to use -1.
if (isOneConstant(N01)) {
if (!isOneConstant(N11) && !(IsAnd && isAllOnesConstant(N11)))
return SDValue();
} else if (isOneConstant(N11)) {
// N01 and N11 being 1 was already handled. Handle N11==1 and N01==-1.
if (!(IsAnd && isAllOnesConstant(N01)))
return SDValue();
} else
return SDValue();
EVT VT = N->getValueType(0);
SDValue N00 = N0.getOperand(0);
SDValue N10 = N1.getOperand(0);
// The LHS of the xors needs to be 0/1.
APInt Mask = APInt::getBitsSetFrom(VT.getSizeInBits(), 1);
if (!DAG.MaskedValueIsZero(N00, Mask) || !DAG.MaskedValueIsZero(N10, Mask))
return SDValue();
// Invert the opcode and insert a new xor.
SDLoc DL(N);
unsigned Opc = IsAnd ? ISD::OR : ISD::AND;
SDValue Logic = DAG.getNode(Opc, DL, VT, N00, N10);
return DAG.getNode(ISD::XOR, DL, VT, Logic, DAG.getConstant(1, DL, VT));
}
static SDValue performTRUNCATECombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
// Pre-promote (i1 (truncate (srl X, Y))) on RV64 with Zbs without zero
// extending X. This is safe since we only need the LSB after the shift and
// shift amounts larger than 31 would produce poison. If we wait until
// type legalization, we'll create RISCVISD::SRLW and we can't recover it
// to use a BEXT instruction.
if (Subtarget.is64Bit() && Subtarget.hasStdExtZbs() && VT == MVT::i1 &&
N0.getValueType() == MVT::i32 && N0.getOpcode() == ISD::SRL &&
!isa<ConstantSDNode>(N0.getOperand(1)) && N0.hasOneUse()) {
SDLoc DL(N0);
SDValue Op0 = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N0.getOperand(0));
SDValue Op1 = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, N0.getOperand(1));
SDValue Srl = DAG.getNode(ISD::SRL, DL, MVT::i64, Op0, Op1);
return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Srl);
}
return SDValue();
}
namespace {
// Helper class contains information about comparison operation.
// The first two operands of this operation are compared values and the
// last one is the operation.
// Compared values are stored in Ops.
// Comparison operation is stored in CCode.
class CmpOpInfo {
static unsigned constexpr Size = 2u;
// Type for storing operands of compare operation.
using OpsArray = std::array<SDValue, Size>;
OpsArray Ops;
using const_iterator = OpsArray::const_iterator;
const_iterator begin() const { return Ops.begin(); }
const_iterator end() const { return Ops.end(); }
ISD::CondCode CCode;
unsigned CommonPos{Size};
unsigned DifferPos{Size};
// Sets CommonPos and DifferPos based on incoming position
// of common operand CPos.
void setPositions(const_iterator CPos) {
assert(CPos != Ops.end() && "Common operand has to be in OpsArray.\n");
CommonPos = CPos == Ops.begin() ? 0 : 1;
DifferPos = 1 - CommonPos;
assert((DifferPos == 0 || DifferPos == 1) &&
"Positions can be only 0 or 1.");
}
// Private constructor of comparison info based on comparison operator.
// It is private because CmpOpInfo only reasonable relative to other
// comparison operator. Therefore, infos about comparison operation
// have to be collected simultaneously via CmpOpInfo::getInfoAbout().
CmpOpInfo(const SDValue &CmpOp)
: Ops{CmpOp.getOperand(0), CmpOp.getOperand(1)},
CCode{cast<CondCodeSDNode>(CmpOp.getOperand(2))->get()} {}
// Finds common operand of Op1 and Op2 and finishes filling CmpOpInfos.
// Returns true if common operand is found. Otherwise - false.
static bool establishCorrespondence(CmpOpInfo &Op1, CmpOpInfo &Op2) {
const auto CommonOpIt1 =
std::find_first_of(Op1.begin(), Op1.end(), Op2.begin(), Op2.end());
if (CommonOpIt1 == Op1.end())
return false;
const auto CommonOpIt2 = std::find(Op2.begin(), Op2.end(), *CommonOpIt1);
assert(CommonOpIt2 != Op2.end() &&
"Cannot find common operand in the second comparison operation.");
Op1.setPositions(CommonOpIt1);
Op2.setPositions(CommonOpIt2);
return true;
}
public:
CmpOpInfo(const CmpOpInfo &) = default;
CmpOpInfo(CmpOpInfo &&) = default;
SDValue const &operator[](unsigned Pos) const {
assert(Pos < Size && "Out of range\n");
return Ops[Pos];
}
// Creates infos about comparison operations CmpOp0 and CmpOp1.
// If there is no common operand returns None. Otherwise, returns
// correspondence info about comparison operations.
static std::optional<std::pair<CmpOpInfo, CmpOpInfo>>
getInfoAbout(SDValue const &CmpOp0, SDValue const &CmpOp1) {
CmpOpInfo Op0{CmpOp0};
CmpOpInfo Op1{CmpOp1};
if (!establishCorrespondence(Op0, Op1))
return std::nullopt;
return std::make_pair(Op0, Op1);
}
// Returns position of common operand.
unsigned getCPos() const { return CommonPos; }
// Returns position of differ operand.
unsigned getDPos() const { return DifferPos; }
// Returns common operand.
SDValue const &getCOp() const { return operator[](CommonPos); }
// Returns differ operand.
SDValue const &getDOp() const { return operator[](DifferPos); }
// Returns consition code of comparison operation.
ISD::CondCode getCondCode() const { return CCode; }
};
} // namespace
// Verifies conditions to apply an optimization.
// Returns Reference comparison code and three operands A, B, C.
// Conditions for optimization:
// One operand of the compasions has to be common.
// This operand is written to C.
// Two others operands are differend. They are written to A and B.
// Comparisons has to be similar with respect to common operand C.
// e.g. A < C; C > B are similar
// but A < C; B > C are not.
// Reference comparison code is the comparison code if
// common operand is right placed.
// e.g. C > A will be swapped to A < C.
static std::optional<std::tuple<ISD::CondCode, SDValue, SDValue, SDValue>>
verifyCompareConds(SDNode *N, SelectionDAG &DAG) {
LLVM_DEBUG(
dbgs() << "Checking conditions for comparison operation combining.\n";);
SDValue V0 = N->getOperand(0);
SDValue V1 = N->getOperand(1);
assert(V0.getValueType() == V1.getValueType() &&
"Operations must have the same value type.");
// Condition 1. Operations have to be used only in logic operation.
if (!V0.hasOneUse() || !V1.hasOneUse())
return std::nullopt;
// Condition 2. Operands have to be comparison operations.
if (V0.getOpcode() != ISD::SETCC || V1.getOpcode() != ISD::SETCC)
return std::nullopt;
// Condition 3.1. Operations only with integers.
if (!V0.getOperand(0).getValueType().isInteger())
return std::nullopt;
const auto ComparisonInfo = CmpOpInfo::getInfoAbout(V0, V1);
// Condition 3.2. Common operand has to be in comparison.
if (!ComparisonInfo)
return std::nullopt;
const auto [Op0, Op1] = ComparisonInfo.value();
LLVM_DEBUG(dbgs() << "Shared operands are on positions: " << Op0.getCPos()
<< " and " << Op1.getCPos() << '\n';);
// If common operand at the first position then swap operation to convert to
// strict pattern. Common operand has to be right hand side.
ISD::CondCode RefCond = Op0.getCondCode();
ISD::CondCode AssistCode = Op1.getCondCode();
if (!Op0.getCPos())
RefCond = ISD::getSetCCSwappedOperands(RefCond);
if (!Op1.getCPos())
AssistCode = ISD::getSetCCSwappedOperands(AssistCode);
LLVM_DEBUG(dbgs() << "Reference condition is: " << RefCond << '\n';);
// If there are different comparison operations then do not perform an
// optimization. a < c; c < b -> will be changed to b > c.
if (RefCond != AssistCode)
return std::nullopt;
// Conditions can be only similar to Less or Greater. (>, >=, <, <=)
// Applying this mask to the operation will determine Less and Greater
// operations.
const unsigned CmpMask = 0b110;
const unsigned MaskedOpcode = CmpMask & RefCond;
// If masking gave 0b110, then this is an operation NE, O or TRUE.
if (MaskedOpcode == CmpMask)
return std::nullopt;
// If masking gave 00000, then this is an operation E, O or FALSE.
if (MaskedOpcode == 0)
return std::nullopt;
// Everything else is similar to Less or Greater.
SDValue A = Op0.getDOp();
SDValue B = Op1.getDOp();
SDValue C = Op0.getCOp();
LLVM_DEBUG(
dbgs() << "The conditions for combining comparisons are satisfied.\n";);
return std::make_tuple(RefCond, A, B, C);
}
static ISD::NodeType getSelectionCode(bool IsUnsigned, bool IsAnd,
bool IsGreaterOp) {
// Codes of selection operation. The first index selects signed or unsigned,
// the second index selects MIN/MAX.
static constexpr ISD::NodeType SelectionCodes[2][2] = {
{ISD::SMIN, ISD::SMAX}, {ISD::UMIN, ISD::UMAX}};
const bool ChooseSelCode = IsAnd ^ IsGreaterOp;
return SelectionCodes[IsUnsigned][ChooseSelCode];
}
// Combines two comparison operation and logic operation to one selection
// operation(min, max) and logic operation. Returns new constructed Node if
// conditions for optimization are satisfied.
static SDValue combineCmpOp(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
if (!Subtarget.hasStdExtZbb())
return SDValue();
const unsigned BitOpcode = N->getOpcode();
assert((BitOpcode == ISD::AND || BitOpcode == ISD::OR) &&
"This optimization can be used only with AND/OR operations");
const auto Props = verifyCompareConds(N, DAG);
// If conditions are invalidated then do not perform an optimization.
if (!Props)
return SDValue();
const auto [RefOpcode, A, B, C] = Props.value();
const EVT CmpOpVT = A.getValueType();
const bool IsGreaterOp = RefOpcode & 0b10;
const bool IsUnsigned = ISD::isUnsignedIntSetCC(RefOpcode);
assert((IsUnsigned || ISD::isSignedIntSetCC(RefOpcode)) &&
"Operation neither with signed or unsigned integers.");
const bool IsAnd = BitOpcode == ISD::AND;
const ISD::NodeType PickCode =
getSelectionCode(IsUnsigned, IsAnd, IsGreaterOp);
SDLoc DL(N);
SDValue Pick = DAG.getNode(PickCode, DL, CmpOpVT, A, B);
SDValue Cmp =
DAG.getSetCC(DL, N->getOperand(0).getValueType(), Pick, C, RefOpcode);
return Cmp;
}
static SDValue performANDCombine(SDNode *N,
TargetLowering::DAGCombinerInfo &DCI,
const RISCVSubtarget &Subtarget) {
SelectionDAG &DAG = DCI.DAG;
SDValue N0 = N->getOperand(0);
// Pre-promote (i32 (and (srl X, Y), 1)) on RV64 with Zbs without zero
// extending X. This is safe since we only need the LSB after the shift and
// shift amounts larger than 31 would produce poison. If we wait until
// type legalization, we'll create RISCVISD::SRLW and we can't recover it
// to use a BEXT instruction.
if (Subtarget.is64Bit() && Subtarget.hasStdExtZbs() &&
N->getValueType(0) == MVT::i32 && isOneConstant(N->getOperand(1)) &&
N0.getOpcode() == ISD::SRL && !isa<ConstantSDNode>(N0.getOperand(1)) &&
N0.hasOneUse()) {
SDLoc DL(N);
SDValue Op0 = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N0.getOperand(0));
SDValue Op1 = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, N0.getOperand(1));
SDValue Srl = DAG.getNode(ISD::SRL, DL, MVT::i64, Op0, Op1);
SDValue And = DAG.getNode(ISD::AND, DL, MVT::i64, Srl,
DAG.getConstant(1, DL, MVT::i64));
return DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, And);
}
if (SDValue V = combineCmpOp(N, DAG, Subtarget))
return V;
if (SDValue V = combineBinOpToReduce(N, DAG, Subtarget))
return V;
if (DCI.isAfterLegalizeDAG())
if (SDValue V = combineDeMorganOfBoolean(N, DAG))
return V;
// fold (and (select lhs, rhs, cc, -1, y), x) ->
// (select lhs, rhs, cc, x, (and x, y))
return combineSelectAndUseCommutative(N, DAG, /*AllOnes*/ true, Subtarget);
}
static SDValue performORCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI,
const RISCVSubtarget &Subtarget) {
SelectionDAG &DAG = DCI.DAG;
if (SDValue V = combineCmpOp(N, DAG, Subtarget))
return V;
if (SDValue V = combineBinOpToReduce(N, DAG, Subtarget))
return V;
if (DCI.isAfterLegalizeDAG())
if (SDValue V = combineDeMorganOfBoolean(N, DAG))
return V;
// fold (or (select cond, 0, y), x) ->
// (select cond, x, (or x, y))
return combineSelectAndUseCommutative(N, DAG, /*AllOnes*/ false, Subtarget);
}
static SDValue performXORCombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
// fold (xor (sllw 1, x), -1) -> (rolw ~1, x)
// NOTE: Assumes ROL being legal means ROLW is legal.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (N0.getOpcode() == RISCVISD::SLLW &&
isAllOnesConstant(N1) && isOneConstant(N0.getOperand(0)) &&
TLI.isOperationLegal(ISD::ROTL, MVT::i64)) {
SDLoc DL(N);
return DAG.getNode(RISCVISD::ROLW, DL, MVT::i64,
DAG.getConstant(~1, DL, MVT::i64), N0.getOperand(1));
}
if (SDValue V = combineBinOpToReduce(N, DAG, Subtarget))
return V;
// fold (xor (select cond, 0, y), x) ->
// (select cond, x, (xor x, y))
return combineSelectAndUseCommutative(N, DAG, /*AllOnes*/ false, Subtarget);
}
// Replace (seteq (i64 (and X, 0xffffffff)), C1) with
// (seteq (i64 (sext_inreg (X, i32)), C1')) where C1' is C1 sign extended from
// bit 31. Same for setne. C1' may be cheaper to materialize and the sext_inreg
// can become a sext.w instead of a shift pair.
static SDValue performSETCCCombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
EVT OpVT = N0.getValueType();
if (OpVT != MVT::i64 || !Subtarget.is64Bit())
return SDValue();
// RHS needs to be a constant.
auto *N1C = dyn_cast<ConstantSDNode>(N1);
if (!N1C)
return SDValue();
// LHS needs to be (and X, 0xffffffff).
if (N0.getOpcode() != ISD::AND || !N0.hasOneUse() ||
!isa<ConstantSDNode>(N0.getOperand(1)) ||
N0.getConstantOperandVal(1) != UINT64_C(0xffffffff))
return SDValue();
// Looking for an equality compare.
ISD::CondCode Cond = cast<CondCodeSDNode>(N->getOperand(2))->get();
if (!isIntEqualitySetCC(Cond))
return SDValue();
// Don't do this if the sign bit is provably zero, it will be turned back into
// an AND.
APInt SignMask = APInt::getOneBitSet(64, 31);
if (DAG.MaskedValueIsZero(N0.getOperand(0), SignMask))
return SDValue();
const APInt &C1 = N1C->getAPIntValue();
SDLoc dl(N);
// If the constant is larger than 2^32 - 1 it is impossible for both sides
// to be equal.
if (C1.getActiveBits() > 32)
return DAG.getBoolConstant(Cond == ISD::SETNE, dl, VT, OpVT);
SDValue SExtOp = DAG.getNode(ISD::SIGN_EXTEND_INREG, N, OpVT,
N0.getOperand(0), DAG.getValueType(MVT::i32));
return DAG.getSetCC(dl, VT, SExtOp, DAG.getConstant(C1.trunc(32).sext(64),
dl, OpVT), Cond);
}
static SDValue
performSIGN_EXTEND_INREGCombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
SDValue Src = N->getOperand(0);
EVT VT = N->getValueType(0);
// Fold (sext_inreg (fmv_x_anyexth X), i16) -> (fmv_x_signexth X)
if (Src.getOpcode() == RISCVISD::FMV_X_ANYEXTH &&
cast<VTSDNode>(N->getOperand(1))->getVT().bitsGE(MVT::i16))
return DAG.getNode(RISCVISD::FMV_X_SIGNEXTH, SDLoc(N), VT,
Src.getOperand(0));
return SDValue();
}
namespace {
// Forward declaration of the structure holding the necessary information to
// apply a combine.
struct CombineResult;
/// Helper class for folding sign/zero extensions.
/// In particular, this class is used for the following combines:
/// add_vl -> vwadd(u) | vwadd(u)_w
/// sub_vl -> vwsub(u) | vwsub(u)_w
/// mul_vl -> vwmul(u) | vwmul_su
///
/// An object of this class represents an operand of the operation we want to
/// combine.
/// E.g., when trying to combine `mul_vl a, b`, we will have one instance of
/// NodeExtensionHelper for `a` and one for `b`.
///
/// This class abstracts away how the extension is materialized and
/// how its Mask, VL, number of users affect the combines.
///
/// In particular:
/// - VWADD_W is conceptually == add(op0, sext(op1))
/// - VWADDU_W == add(op0, zext(op1))
/// - VWSUB_W == sub(op0, sext(op1))
/// - VWSUBU_W == sub(op0, zext(op1))
///
/// And VMV_V_X_VL, depending on the value, is conceptually equivalent to
/// zext|sext(smaller_value).
struct NodeExtensionHelper {
/// Records if this operand is like being zero extended.
bool SupportsZExt;
/// Records if this operand is like being sign extended.
/// Note: SupportsZExt and SupportsSExt are not mutually exclusive. For
/// instance, a splat constant (e.g., 3), would support being both sign and
/// zero extended.
bool SupportsSExt;
/// This boolean captures whether we care if this operand would still be
/// around after the folding happens.
bool EnforceOneUse;
/// Records if this operand's mask needs to match the mask of the operation
/// that it will fold into.
bool CheckMask;
/// Value of the Mask for this operand.
/// It may be SDValue().
SDValue Mask;
/// Value of the vector length operand.
/// It may be SDValue().
SDValue VL;
/// Original value that this NodeExtensionHelper represents.
SDValue OrigOperand;
/// Get the value feeding the extension or the value itself.
/// E.g., for zext(a), this would return a.
SDValue getSource() const {
switch (OrigOperand.getOpcode()) {
case RISCVISD::VSEXT_VL:
case RISCVISD::VZEXT_VL:
return OrigOperand.getOperand(0);
default:
return OrigOperand;
}
}
/// Check if this instance represents a splat.
bool isSplat() const {
return OrigOperand.getOpcode() == RISCVISD::VMV_V_X_VL;
}
/// Get or create a value that can feed \p Root with the given extension \p
/// SExt. If \p SExt is None, this returns the source of this operand.
/// \see ::getSource().
SDValue getOrCreateExtendedOp(const SDNode *Root, SelectionDAG &DAG,
std::optional<bool> SExt) const {
if (!SExt.has_value())
return OrigOperand;
MVT NarrowVT = getNarrowType(Root);
SDValue Source = getSource();
if (Source.getValueType() == NarrowVT)
return Source;
unsigned ExtOpc = *SExt ? RISCVISD::VSEXT_VL : RISCVISD::VZEXT_VL;
// If we need an extension, we should be changing the type.
SDLoc DL(Root);
auto [Mask, VL] = getMaskAndVL(Root);
switch (OrigOperand.getOpcode()) {
case RISCVISD::VSEXT_VL:
case RISCVISD::VZEXT_VL:
return DAG.getNode(ExtOpc, DL, NarrowVT, Source, Mask, VL);
case RISCVISD::VMV_V_X_VL:
return DAG.getNode(RISCVISD::VMV_V_X_VL, DL, NarrowVT,
DAG.getUNDEF(NarrowVT), Source.getOperand(1), VL);
default:
// Other opcodes can only come from the original LHS of VW(ADD|SUB)_W_VL
// and that operand should already have the right NarrowVT so no
// extension should be required at this point.
llvm_unreachable("Unsupported opcode");
}
}
/// Helper function to get the narrow type for \p Root.
/// The narrow type is the type of \p Root where we divided the size of each
/// element by 2. E.g., if Root's type <2xi16> -> narrow type <2xi8>.
/// \pre The size of the type of the elements of Root must be a multiple of 2
/// and be greater than 16.
static MVT getNarrowType(const SDNode *Root) {
MVT VT = Root->getSimpleValueType(0);
// Determine the narrow size.
unsigned NarrowSize = VT.getScalarSizeInBits() / 2;
assert(NarrowSize >= 8 && "Trying to extend something we can't represent");
MVT NarrowVT = MVT::getVectorVT(MVT::getIntegerVT(NarrowSize),
VT.getVectorElementCount());
return NarrowVT;
}
/// Return the opcode required to materialize the folding of the sign
/// extensions (\p IsSExt == true) or zero extensions (IsSExt == false) for
/// both operands for \p Opcode.
/// Put differently, get the opcode to materialize:
/// - ISExt == true: \p Opcode(sext(a), sext(b)) -> newOpcode(a, b)
/// - ISExt == false: \p Opcode(zext(a), zext(b)) -> newOpcode(a, b)
/// \pre \p Opcode represents a supported root (\see ::isSupportedRoot()).
static unsigned getSameExtensionOpcode(unsigned Opcode, bool IsSExt) {
switch (Opcode) {
case RISCVISD::ADD_VL:
case RISCVISD::VWADD_W_VL:
case RISCVISD::VWADDU_W_VL:
return IsSExt ? RISCVISD::VWADD_VL : RISCVISD::VWADDU_VL;
case RISCVISD::MUL_VL:
return IsSExt ? RISCVISD::VWMUL_VL : RISCVISD::VWMULU_VL;
case RISCVISD::SUB_VL:
case RISCVISD::VWSUB_W_VL:
case RISCVISD::VWSUBU_W_VL:
return IsSExt ? RISCVISD::VWSUB_VL : RISCVISD::VWSUBU_VL;
default:
llvm_unreachable("Unexpected opcode");
}
}
/// Get the opcode to materialize \p Opcode(sext(a), zext(b)) ->
/// newOpcode(a, b).
static unsigned getSUOpcode(unsigned Opcode) {
assert(Opcode == RISCVISD::MUL_VL && "SU is only supported for MUL");
return RISCVISD::VWMULSU_VL;
}
/// Get the opcode to materialize \p Opcode(a, s|zext(b)) ->
/// newOpcode(a, b).
static unsigned getWOpcode(unsigned Opcode, bool IsSExt) {
switch (Opcode) {
case RISCVISD::ADD_VL:
return IsSExt ? RISCVISD::VWADD_W_VL : RISCVISD::VWADDU_W_VL;
case RISCVISD::SUB_VL:
return IsSExt ? RISCVISD::VWSUB_W_VL : RISCVISD::VWSUBU_W_VL;
default:
llvm_unreachable("Unexpected opcode");
}
}
using CombineToTry = std::function<std::optional<CombineResult>(
SDNode * /*Root*/, const NodeExtensionHelper & /*LHS*/,
const NodeExtensionHelper & /*RHS*/)>;
/// Check if this node needs to be fully folded or extended for all users.
bool needToPromoteOtherUsers() const { return EnforceOneUse; }
/// Helper method to set the various fields of this struct based on the
/// type of \p Root.
void fillUpExtensionSupport(SDNode *Root, SelectionDAG &DAG) {
SupportsZExt = false;
SupportsSExt = false;
EnforceOneUse = true;
CheckMask = true;
switch (OrigOperand.getOpcode()) {
case RISCVISD::VZEXT_VL:
SupportsZExt = true;
Mask = OrigOperand.getOperand(1);
VL = OrigOperand.getOperand(2);
break;
case RISCVISD::VSEXT_VL:
SupportsSExt = true;
Mask = OrigOperand.getOperand(1);
VL = OrigOperand.getOperand(2);
break;
case RISCVISD::VMV_V_X_VL: {
// Historically, we didn't care about splat values not disappearing during
// combines.
EnforceOneUse = false;
CheckMask = false;
VL = OrigOperand.getOperand(2);
// The operand is a splat of a scalar.
// The pasthru must be undef for tail agnostic.
if (!OrigOperand.getOperand(0).isUndef())
break;
// Get the scalar value.
SDValue Op = OrigOperand.getOperand(1);
// See if we have enough sign bits or zero bits in the scalar to use a
// widening opcode by splatting to smaller element size.
MVT VT = Root->getSimpleValueType(0);
unsigned EltBits = VT.getScalarSizeInBits();
unsigned ScalarBits = Op.getValueSizeInBits();
// Make sure we're getting all element bits from the scalar register.
// FIXME: Support implicit sign extension of vmv.v.x?
if (ScalarBits < EltBits)
break;
unsigned NarrowSize = VT.getScalarSizeInBits() / 2;
// If the narrow type cannot be expressed with a legal VMV,
// this is not a valid candidate.
if (NarrowSize < 8)
break;
if (DAG.ComputeMaxSignificantBits(Op) <= NarrowSize)
SupportsSExt = true;
if (DAG.MaskedValueIsZero(Op,
APInt::getBitsSetFrom(ScalarBits, NarrowSize)))
SupportsZExt = true;
break;
}
default:
break;
}
}
/// Check if \p Root supports any extension folding combines.
static bool isSupportedRoot(const SDNode *Root) {
switch (Root->getOpcode()) {
case RISCVISD::ADD_VL:
case RISCVISD::MUL_VL:
case RISCVISD::VWADD_W_VL:
case RISCVISD::VWADDU_W_VL:
case RISCVISD::SUB_VL:
case RISCVISD::VWSUB_W_VL:
case RISCVISD::VWSUBU_W_VL:
return true;
default:
return false;
}
}
/// Build a NodeExtensionHelper for \p Root.getOperand(\p OperandIdx).
NodeExtensionHelper(SDNode *Root, unsigned OperandIdx, SelectionDAG &DAG) {
assert(isSupportedRoot(Root) && "Trying to build an helper with an "
"unsupported root");
assert(OperandIdx < 2 && "Requesting something else than LHS or RHS");
OrigOperand = Root->getOperand(OperandIdx);
unsigned Opc = Root->getOpcode();
switch (Opc) {
// We consider VW<ADD|SUB>(U)_W(LHS, RHS) as if they were
// <ADD|SUB>(LHS, S|ZEXT(RHS))
case RISCVISD::VWADD_W_VL:
case RISCVISD::VWADDU_W_VL:
case RISCVISD::VWSUB_W_VL:
case RISCVISD::VWSUBU_W_VL:
if (OperandIdx == 1) {
SupportsZExt =
Opc == RISCVISD::VWADDU_W_VL || Opc == RISCVISD::VWSUBU_W_VL;
SupportsSExt = !SupportsZExt;
std::tie(Mask, VL) = getMaskAndVL(Root);
CheckMask = true;
// There's no existing extension here, so we don't have to worry about
// making sure it gets removed.
EnforceOneUse = false;
break;
}
[[fallthrough]];
default:
fillUpExtensionSupport(Root, DAG);
break;
}
}
/// Check if this operand is compatible with the given vector length \p VL.
bool isVLCompatible(SDValue VL) const {
return this->VL != SDValue() && this->VL == VL;
}
/// Check if this operand is compatible with the given \p Mask.
bool isMaskCompatible(SDValue Mask) const {
return !CheckMask || (this->Mask != SDValue() && this->Mask == Mask);
}
/// Helper function to get the Mask and VL from \p Root.
static std::pair<SDValue, SDValue> getMaskAndVL(const SDNode *Root) {
assert(isSupportedRoot(Root) && "Unexpected root");
return std::make_pair(Root->getOperand(3), Root->getOperand(4));
}
/// Check if the Mask and VL of this operand are compatible with \p Root.
bool areVLAndMaskCompatible(const SDNode *Root) const {
auto [Mask, VL] = getMaskAndVL(Root);
return isMaskCompatible(Mask) && isVLCompatible(VL);
}
/// Helper function to check if \p N is commutative with respect to the
/// foldings that are supported by this class.
static bool isCommutative(const SDNode *N) {
switch (N->getOpcode()) {
case RISCVISD::ADD_VL:
case RISCVISD::MUL_VL:
case RISCVISD::VWADD_W_VL:
case RISCVISD::VWADDU_W_VL:
return true;
case RISCVISD::SUB_VL:
case RISCVISD::VWSUB_W_VL:
case RISCVISD::VWSUBU_W_VL:
return false;
default:
llvm_unreachable("Unexpected opcode");
}
}
/// Get a list of combine to try for folding extensions in \p Root.
/// Note that each returned CombineToTry function doesn't actually modify
/// anything. Instead they produce an optional CombineResult that if not None,
/// need to be materialized for the combine to be applied.
/// \see CombineResult::materialize.
/// If the related CombineToTry function returns std::nullopt, that means the
/// combine didn't match.
static SmallVector<CombineToTry> getSupportedFoldings(const SDNode *Root);
};
/// Helper structure that holds all the necessary information to materialize a
/// combine that does some extension folding.
struct CombineResult {
/// Opcode to be generated when materializing the combine.
unsigned TargetOpcode;
// No value means no extension is needed. If extension is needed, the value
// indicates if it needs to be sign extended.
std::optional<bool> SExtLHS;
std::optional<bool> SExtRHS;
/// Root of the combine.
SDNode *Root;
/// LHS of the TargetOpcode.
NodeExtensionHelper LHS;
/// RHS of the TargetOpcode.
NodeExtensionHelper RHS;
CombineResult(unsigned TargetOpcode, SDNode *Root,
const NodeExtensionHelper &LHS, std::optional<bool> SExtLHS,
const NodeExtensionHelper &RHS, std::optional<bool> SExtRHS)
: TargetOpcode(TargetOpcode), SExtLHS(SExtLHS), SExtRHS(SExtRHS),
Root(Root), LHS(LHS), RHS(RHS) {}
/// Return a value that uses TargetOpcode and that can be used to replace
/// Root.
/// The actual replacement is *not* done in that method.
SDValue materialize(SelectionDAG &DAG) const {
SDValue Mask, VL, Merge;
std::tie(Mask, VL) = NodeExtensionHelper::getMaskAndVL(Root);
Merge = Root->getOperand(2);
return DAG.getNode(TargetOpcode, SDLoc(Root), Root->getValueType(0),
LHS.getOrCreateExtendedOp(Root, DAG, SExtLHS),
RHS.getOrCreateExtendedOp(Root, DAG, SExtRHS), Merge,
Mask, VL);
}
};
/// Check if \p Root follows a pattern Root(ext(LHS), ext(RHS))
/// where `ext` is the same for both LHS and RHS (i.e., both are sext or both
/// are zext) and LHS and RHS can be folded into Root.
/// AllowSExt and AllozZExt define which form `ext` can take in this pattern.
///
/// \note If the pattern can match with both zext and sext, the returned
/// CombineResult will feature the zext result.
///
/// \returns std::nullopt if the pattern doesn't match or a CombineResult that
/// can be used to apply the pattern.
static std::optional<CombineResult>
canFoldToVWWithSameExtensionImpl(SDNode *Root, const NodeExtensionHelper &LHS,
const NodeExtensionHelper &RHS, bool AllowSExt,
bool AllowZExt) {
assert((AllowSExt || AllowZExt) && "Forgot to set what you want?");
if (!LHS.areVLAndMaskCompatible(Root) || !RHS.areVLAndMaskCompatible(Root))
return std::nullopt;
if (AllowZExt && LHS.SupportsZExt && RHS.SupportsZExt)
return CombineResult(NodeExtensionHelper::getSameExtensionOpcode(
Root->getOpcode(), /*IsSExt=*/false),
Root, LHS, /*SExtLHS=*/false, RHS,
/*SExtRHS=*/false);
if (AllowSExt && LHS.SupportsSExt && RHS.SupportsSExt)
return CombineResult(NodeExtensionHelper::getSameExtensionOpcode(
Root->getOpcode(), /*IsSExt=*/true),
Root, LHS, /*SExtLHS=*/true, RHS,
/*SExtRHS=*/true);
return std::nullopt;
}
/// Check if \p Root follows a pattern Root(ext(LHS), ext(RHS))
/// where `ext` is the same for both LHS and RHS (i.e., both are sext or both
/// are zext) and LHS and RHS can be folded into Root.
///
/// \returns std::nullopt if the pattern doesn't match or a CombineResult that
/// can be used to apply the pattern.
static std::optional<CombineResult>
canFoldToVWWithSameExtension(SDNode *Root, const NodeExtensionHelper &LHS,
const NodeExtensionHelper &RHS) {
return canFoldToVWWithSameExtensionImpl(Root, LHS, RHS, /*AllowSExt=*/true,
/*AllowZExt=*/true);
}
/// Check if \p Root follows a pattern Root(LHS, ext(RHS))
///
/// \returns std::nullopt if the pattern doesn't match or a CombineResult that
/// can be used to apply the pattern.
static std::optional<CombineResult>
canFoldToVW_W(SDNode *Root, const NodeExtensionHelper &LHS,
const NodeExtensionHelper &RHS) {
if (!RHS.areVLAndMaskCompatible(Root))
return std::nullopt;
// FIXME: Is it useful to form a vwadd.wx or vwsub.wx if it removes a scalar
// sext/zext?
// Control this behavior behind an option (AllowSplatInVW_W) for testing
// purposes.
if (RHS.SupportsZExt && (!RHS.isSplat() || AllowSplatInVW_W))
return CombineResult(
NodeExtensionHelper::getWOpcode(Root->getOpcode(), /*IsSExt=*/false),
Root, LHS, /*SExtLHS=*/std::nullopt, RHS, /*SExtRHS=*/false);
if (RHS.SupportsSExt && (!RHS.isSplat() || AllowSplatInVW_W))
return CombineResult(
NodeExtensionHelper::getWOpcode(Root->getOpcode(), /*IsSExt=*/true),
Root, LHS, /*SExtLHS=*/std::nullopt, RHS, /*SExtRHS=*/true);
return std::nullopt;
}
/// Check if \p Root follows a pattern Root(sext(LHS), sext(RHS))
///
/// \returns std::nullopt if the pattern doesn't match or a CombineResult that
/// can be used to apply the pattern.
static std::optional<CombineResult>
canFoldToVWWithSEXT(SDNode *Root, const NodeExtensionHelper &LHS,
const NodeExtensionHelper &RHS) {
return canFoldToVWWithSameExtensionImpl(Root, LHS, RHS, /*AllowSExt=*/true,
/*AllowZExt=*/false);
}
/// Check if \p Root follows a pattern Root(zext(LHS), zext(RHS))
///
/// \returns std::nullopt if the pattern doesn't match or a CombineResult that
/// can be used to apply the pattern.
static std::optional<CombineResult>
canFoldToVWWithZEXT(SDNode *Root, const NodeExtensionHelper &LHS,
const NodeExtensionHelper &RHS) {
return canFoldToVWWithSameExtensionImpl(Root, LHS, RHS, /*AllowSExt=*/false,
/*AllowZExt=*/true);
}
/// Check if \p Root follows a pattern Root(sext(LHS), zext(RHS))
///
/// \returns std::nullopt if the pattern doesn't match or a CombineResult that
/// can be used to apply the pattern.
static std::optional<CombineResult>
canFoldToVW_SU(SDNode *Root, const NodeExtensionHelper &LHS,
const NodeExtensionHelper &RHS) {
if (!LHS.SupportsSExt || !RHS.SupportsZExt)
return std::nullopt;
if (!LHS.areVLAndMaskCompatible(Root) || !RHS.areVLAndMaskCompatible(Root))
return std::nullopt;
return CombineResult(NodeExtensionHelper::getSUOpcode(Root->getOpcode()),
Root, LHS, /*SExtLHS=*/true, RHS, /*SExtRHS=*/false);
}
SmallVector<NodeExtensionHelper::CombineToTry>
NodeExtensionHelper::getSupportedFoldings(const SDNode *Root) {
SmallVector<CombineToTry> Strategies;
switch (Root->getOpcode()) {
case RISCVISD::ADD_VL:
case RISCVISD::SUB_VL:
// add|sub -> vwadd(u)|vwsub(u)
Strategies.push_back(canFoldToVWWithSameExtension);
// add|sub -> vwadd(u)_w|vwsub(u)_w
Strategies.push_back(canFoldToVW_W);
break;
case RISCVISD::MUL_VL:
// mul -> vwmul(u)
Strategies.push_back(canFoldToVWWithSameExtension);
// mul -> vwmulsu
Strategies.push_back(canFoldToVW_SU);
break;
case RISCVISD::VWADD_W_VL:
case RISCVISD::VWSUB_W_VL:
// vwadd_w|vwsub_w -> vwadd|vwsub
Strategies.push_back(canFoldToVWWithSEXT);
break;
case RISCVISD::VWADDU_W_VL:
case RISCVISD::VWSUBU_W_VL:
// vwaddu_w|vwsubu_w -> vwaddu|vwsubu
Strategies.push_back(canFoldToVWWithZEXT);
break;
default:
llvm_unreachable("Unexpected opcode");
}
return Strategies;
}
} // End anonymous namespace.
/// Combine a binary operation to its equivalent VW or VW_W form.
/// The supported combines are:
/// add_vl -> vwadd(u) | vwadd(u)_w
/// sub_vl -> vwsub(u) | vwsub(u)_w
/// mul_vl -> vwmul(u) | vwmul_su
/// vwadd_w(u) -> vwadd(u)
/// vwub_w(u) -> vwadd(u)
static SDValue
combineBinOp_VLToVWBinOp_VL(SDNode *N, TargetLowering::DAGCombinerInfo &DCI) {
SelectionDAG &DAG = DCI.DAG;
assert(NodeExtensionHelper::isSupportedRoot(N) &&
"Shouldn't have called this method");
SmallVector<SDNode *> Worklist;
SmallSet<SDNode *, 8> Inserted;
Worklist.push_back(N);
Inserted.insert(N);
SmallVector<CombineResult> CombinesToApply;
while (!Worklist.empty()) {
SDNode *Root = Worklist.pop_back_val();
if (!NodeExtensionHelper::isSupportedRoot(Root))
return SDValue();
NodeExtensionHelper LHS(N, 0, DAG);
NodeExtensionHelper RHS(N, 1, DAG);
auto AppendUsersIfNeeded = [&Worklist,
&Inserted](const NodeExtensionHelper &Op) {
if (Op.needToPromoteOtherUsers()) {
for (SDNode *TheUse : Op.OrigOperand->uses()) {
if (Inserted.insert(TheUse).second)
Worklist.push_back(TheUse);
}
}
};
// Control the compile time by limiting the number of node we look at in
// total.
if (Inserted.size() > ExtensionMaxWebSize)
return SDValue();
SmallVector<NodeExtensionHelper::CombineToTry> FoldingStrategies =
NodeExtensionHelper::getSupportedFoldings(N);
assert(!FoldingStrategies.empty() && "Nothing to be folded");
bool Matched = false;
for (int Attempt = 0;
(Attempt != 1 + NodeExtensionHelper::isCommutative(N)) && !Matched;
++Attempt) {
for (NodeExtensionHelper::CombineToTry FoldingStrategy :
FoldingStrategies) {
std::optional<CombineResult> Res = FoldingStrategy(N, LHS, RHS);
if (Res) {
Matched = true;
CombinesToApply.push_back(*Res);
// All the inputs that are extended need to be folded, otherwise
// we would be leaving the old input (since it is may still be used),
// and the new one.
if (Res->SExtLHS.has_value())
AppendUsersIfNeeded(LHS);
if (Res->SExtRHS.has_value())
AppendUsersIfNeeded(RHS);
break;
}
}
std::swap(LHS, RHS);
}
// Right now we do an all or nothing approach.
if (!Matched)
return SDValue();
}
// Store the value for the replacement of the input node separately.
SDValue InputRootReplacement;
// We do the RAUW after we materialize all the combines, because some replaced
// nodes may be feeding some of the yet-to-be-replaced nodes. Put differently,
// some of these nodes may appear in the NodeExtensionHelpers of some of the
// yet-to-be-visited CombinesToApply roots.
SmallVector<std::pair<SDValue, SDValue>> ValuesToReplace;
ValuesToReplace.reserve(CombinesToApply.size());
for (CombineResult Res : CombinesToApply) {
SDValue NewValue = Res.materialize(DAG);
if (!InputRootReplacement) {
assert(Res.Root == N &&
"First element is expected to be the current node");
InputRootReplacement = NewValue;
} else {
ValuesToReplace.emplace_back(SDValue(Res.Root, 0), NewValue);
}
}
for (std::pair<SDValue, SDValue> OldNewValues : ValuesToReplace) {
DAG.ReplaceAllUsesOfValueWith(OldNewValues.first, OldNewValues.second);
DCI.AddToWorklist(OldNewValues.second.getNode());
}
return InputRootReplacement;
}
// Helper function for performMemPairCombine.
// Try to combine the memory loads/stores LSNode1 and LSNode2
// into a single memory pair operation.
static SDValue tryMemPairCombine(SelectionDAG &DAG, LSBaseSDNode *LSNode1,
LSBaseSDNode *LSNode2, SDValue BasePtr,
uint64_t Imm) {
SmallPtrSet<const SDNode *, 32> Visited;
SmallVector<const SDNode *, 8> Worklist = {LSNode1, LSNode2};
if (SDNode::hasPredecessorHelper(LSNode1, Visited, Worklist) ||
SDNode::hasPredecessorHelper(LSNode2, Visited, Worklist))
return SDValue();
MachineFunction &MF = DAG.getMachineFunction();
const RISCVSubtarget &Subtarget = MF.getSubtarget<RISCVSubtarget>();
// The new operation has twice the width.
MVT XLenVT = Subtarget.getXLenVT();
EVT MemVT = LSNode1->getMemoryVT();
EVT NewMemVT = (MemVT == MVT::i32) ? MVT::i64 : MVT::i128;
MachineMemOperand *MMO = LSNode1->getMemOperand();
MachineMemOperand *NewMMO = MF.getMachineMemOperand(
MMO, MMO->getPointerInfo(), MemVT == MVT::i32 ? 8 : 16);
if (LSNode1->getOpcode() == ISD::LOAD) {
auto Ext = cast<LoadSDNode>(LSNode1)->getExtensionType();
unsigned Opcode;
if (MemVT == MVT::i32)
Opcode = (Ext == ISD::ZEXTLOAD) ? RISCVISD::TH_LWUD : RISCVISD::TH_LWD;
else
Opcode = RISCVISD::TH_LDD;
SDValue Res = DAG.getMemIntrinsicNode(
Opcode, SDLoc(LSNode1), DAG.getVTList({XLenVT, XLenVT, MVT::Other}),
{LSNode1->getChain(), BasePtr,
DAG.getConstant(Imm, SDLoc(LSNode1), XLenVT)},
NewMemVT, NewMMO);
SDValue Node1 =
DAG.getMergeValues({Res.getValue(0), Res.getValue(2)}, SDLoc(LSNode1));
SDValue Node2 =
DAG.getMergeValues({Res.getValue(1), Res.getValue(2)}, SDLoc(LSNode2));
DAG.ReplaceAllUsesWith(LSNode2, Node2.getNode());
return Node1;
} else {
unsigned Opcode = (MemVT == MVT::i32) ? RISCVISD::TH_SWD : RISCVISD::TH_SDD;
SDValue Res = DAG.getMemIntrinsicNode(
Opcode, SDLoc(LSNode1), DAG.getVTList(MVT::Other),
{LSNode1->getChain(), LSNode1->getOperand(1), LSNode2->getOperand(1),
BasePtr, DAG.getConstant(Imm, SDLoc(LSNode1), XLenVT)},
NewMemVT, NewMMO);
DAG.ReplaceAllUsesWith(LSNode2, Res.getNode());
return Res;
}
}
// Try to combine two adjacent loads/stores to a single pair instruction from
// the XTHeadMemPair vendor extension.
static SDValue performMemPairCombine(SDNode *N,
TargetLowering::DAGCombinerInfo &DCI) {
SelectionDAG &DAG = DCI.DAG;
MachineFunction &MF = DAG.getMachineFunction();
const RISCVSubtarget &Subtarget = MF.getSubtarget<RISCVSubtarget>();
// Target does not support load/store pair.
if (!Subtarget.hasVendorXTHeadMemPair())
return SDValue();
LSBaseSDNode *LSNode1 = cast<LSBaseSDNode>(N);
EVT MemVT = LSNode1->getMemoryVT();
unsigned OpNum = LSNode1->getOpcode() == ISD::LOAD ? 1 : 2;
// No volatile, indexed or atomic loads/stores.
if (!LSNode1->isSimple() || LSNode1->isIndexed())
return SDValue();
// Function to get a base + constant representation from a memory value.
auto ExtractBaseAndOffset = [](SDValue Ptr) -> std::pair<SDValue, uint64_t> {
if (Ptr->getOpcode() == ISD::ADD)
if (auto *C1 = dyn_cast<ConstantSDNode>(Ptr->getOperand(1)))
return {Ptr->getOperand(0), C1->getZExtValue()};
return {Ptr, 0};
};
auto [Base1, Offset1] = ExtractBaseAndOffset(LSNode1->getOperand(OpNum));
SDValue Chain = N->getOperand(0);
for (SDNode::use_iterator UI = Chain->use_begin(), UE = Chain->use_end();
UI != UE; ++UI) {
SDUse &Use = UI.getUse();
if (Use.getUser() != N && Use.getResNo() == 0 &&
Use.getUser()->getOpcode() == N->getOpcode()) {
LSBaseSDNode *LSNode2 = cast<LSBaseSDNode>(Use.getUser());
// No volatile, indexed or atomic loads/stores.
if (!LSNode2->isSimple() || LSNode2->isIndexed())
continue;
// Check if LSNode1 and LSNode2 have the same type and extension.
if (LSNode1->getOpcode() == ISD::LOAD)
if (cast<LoadSDNode>(LSNode2)->getExtensionType() !=
cast<LoadSDNode>(LSNode1)->getExtensionType())
continue;
if (LSNode1->getMemoryVT() != LSNode2->getMemoryVT())
continue;
auto [Base2, Offset2] = ExtractBaseAndOffset(LSNode2->getOperand(OpNum));
// Check if the base pointer is the same for both instruction.
if (Base1 != Base2)
continue;
// Check if the offsets match the XTHeadMemPair encoding contraints.
bool Valid = false;
if (MemVT == MVT::i32) {
// Check for adjacent i32 values and a 2-bit index.
if ((Offset1 + 4 == Offset2) && isShiftedUInt<2, 3>(Offset1))
Valid = true;
} else if (MemVT == MVT::i64) {
// Check for adjacent i64 values and a 2-bit index.
if ((Offset1 + 8 == Offset2) && isShiftedUInt<2, 4>(Offset1))
Valid = true;
}
if (!Valid)
continue;
// Try to combine.
if (SDValue Res =
tryMemPairCombine(DAG, LSNode1, LSNode2, Base1, Offset1))
return Res;
}
}
return SDValue();
}
// Fold
// (fp_to_int (froundeven X)) -> fcvt X, rne
// (fp_to_int (ftrunc X)) -> fcvt X, rtz
// (fp_to_int (ffloor X)) -> fcvt X, rdn
// (fp_to_int (fceil X)) -> fcvt X, rup
// (fp_to_int (fround X)) -> fcvt X, rmm
static SDValue performFP_TO_INTCombine(SDNode *N,
TargetLowering::DAGCombinerInfo &DCI,
const RISCVSubtarget &Subtarget) {
SelectionDAG &DAG = DCI.DAG;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
MVT XLenVT = Subtarget.getXLenVT();
SDValue Src = N->getOperand(0);
// Ensure the FP type is legal.
if (!TLI.isTypeLegal(Src.getValueType()))
return SDValue();
// Don't do this for f16 with Zfhmin and not Zfh.
if (Src.getValueType() == MVT::f16 && !Subtarget.hasStdExtZfh())
return SDValue();
RISCVFPRndMode::RoundingMode FRM = matchRoundingOp(Src.getOpcode());
if (FRM == RISCVFPRndMode::Invalid)
return SDValue();
SDLoc DL(N);
bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT;
EVT VT = N->getValueType(0);
if (VT.isVector() && TLI.isTypeLegal(VT)) {
MVT SrcVT = Src.getSimpleValueType();
MVT SrcContainerVT = SrcVT;
MVT ContainerVT = VT.getSimpleVT();
SDValue XVal = Src.getOperand(0);
// For widening and narrowing conversions we just combine it into a
// VFCVT_..._VL node, as there are no specific VFWCVT/VFNCVT VL nodes. They
// end up getting lowered to their appropriate pseudo instructions based on
// their operand types
if (VT.getScalarSizeInBits() > SrcVT.getScalarSizeInBits() * 2 ||
VT.getScalarSizeInBits() * 2 < SrcVT.getScalarSizeInBits())
return SDValue();
// Make fixed-length vectors scalable first
if (SrcVT.isFixedLengthVector()) {
SrcContainerVT = getContainerForFixedLengthVector(DAG, SrcVT, Subtarget);
XVal = convertToScalableVector(SrcContainerVT, XVal, DAG, Subtarget);
ContainerVT =
getContainerForFixedLengthVector(DAG, ContainerVT, Subtarget);
}
auto [Mask, VL] =
getDefaultVLOps(SrcVT, SrcContainerVT, DL, DAG, Subtarget);
SDValue FpToInt;
if (FRM == RISCVFPRndMode::RTZ) {
// Use the dedicated trunc static rounding mode if we're truncating so we
// don't need to generate calls to fsrmi/fsrm
unsigned Opc =
IsSigned ? RISCVISD::VFCVT_RTZ_X_F_VL : RISCVISD::VFCVT_RTZ_XU_F_VL;
FpToInt = DAG.getNode(Opc, DL, ContainerVT, XVal, Mask, VL);
} else {
unsigned Opc =
IsSigned ? RISCVISD::VFCVT_RM_X_F_VL : RISCVISD::VFCVT_RM_XU_F_VL;
FpToInt = DAG.getNode(Opc, DL, ContainerVT, XVal, Mask,
DAG.getTargetConstant(FRM, DL, XLenVT), VL);
}
// If converted from fixed-length to scalable, convert back
if (VT.isFixedLengthVector())
FpToInt = convertFromScalableVector(VT, FpToInt, DAG, Subtarget);
return FpToInt;
}
// Only handle XLen or i32 types. Other types narrower than XLen will
// eventually be legalized to XLenVT.
if (VT != MVT::i32 && VT != XLenVT)
return SDValue();
unsigned Opc;
if (VT == XLenVT)
Opc = IsSigned ? RISCVISD::FCVT_X : RISCVISD::FCVT_XU;
else
Opc = IsSigned ? RISCVISD::FCVT_W_RV64 : RISCVISD::FCVT_WU_RV64;
SDValue FpToInt = DAG.getNode(Opc, DL, XLenVT, Src.getOperand(0),
DAG.getTargetConstant(FRM, DL, XLenVT));
return DAG.getNode(ISD::TRUNCATE, DL, VT, FpToInt);
}
// Fold
// (fp_to_int_sat (froundeven X)) -> (select X == nan, 0, (fcvt X, rne))
// (fp_to_int_sat (ftrunc X)) -> (select X == nan, 0, (fcvt X, rtz))
// (fp_to_int_sat (ffloor X)) -> (select X == nan, 0, (fcvt X, rdn))
// (fp_to_int_sat (fceil X)) -> (select X == nan, 0, (fcvt X, rup))
// (fp_to_int_sat (fround X)) -> (select X == nan, 0, (fcvt X, rmm))
static SDValue performFP_TO_INT_SATCombine(SDNode *N,
TargetLowering::DAGCombinerInfo &DCI,
const RISCVSubtarget &Subtarget) {
SelectionDAG &DAG = DCI.DAG;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
MVT XLenVT = Subtarget.getXLenVT();
// Only handle XLen types. Other types narrower than XLen will eventually be
// legalized to XLenVT.
EVT DstVT = N->getValueType(0);
if (DstVT != XLenVT)
return SDValue();
SDValue Src = N->getOperand(0);
// Ensure the FP type is also legal.
if (!TLI.isTypeLegal(Src.getValueType()))
return SDValue();
// Don't do this for f16 with Zfhmin and not Zfh.
if (Src.getValueType() == MVT::f16 && !Subtarget.hasStdExtZfh())
return SDValue();
EVT SatVT = cast<VTSDNode>(N->getOperand(1))->getVT();
RISCVFPRndMode::RoundingMode FRM = matchRoundingOp(Src.getOpcode());
if (FRM == RISCVFPRndMode::Invalid)
return SDValue();
bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT_SAT;
unsigned Opc;
if (SatVT == DstVT)
Opc = IsSigned ? RISCVISD::FCVT_X : RISCVISD::FCVT_XU;
else if (DstVT == MVT::i64 && SatVT == MVT::i32)
Opc = IsSigned ? RISCVISD::FCVT_W_RV64 : RISCVISD::FCVT_WU_RV64;
else
return SDValue();
// FIXME: Support other SatVTs by clamping before or after the conversion.
Src = Src.getOperand(0);
SDLoc DL(N);
SDValue FpToInt = DAG.getNode(Opc, DL, XLenVT, Src,
DAG.getTargetConstant(FRM, DL, XLenVT));
// fcvt.wu.* sign extends bit 31 on RV64. FP_TO_UINT_SAT expects to zero
// extend.
if (Opc == RISCVISD::FCVT_WU_RV64)
FpToInt = DAG.getZeroExtendInReg(FpToInt, DL, MVT::i32);
// RISC-V FP-to-int conversions saturate to the destination register size, but
// don't produce 0 for nan.
SDValue ZeroInt = DAG.getConstant(0, DL, DstVT);
return DAG.getSelectCC(DL, Src, Src, ZeroInt, FpToInt, ISD::CondCode::SETUO);
}
// Combine (bitreverse (bswap X)) to the BREV8 GREVI encoding if the type is
// smaller than XLenVT.
static SDValue performBITREVERSECombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
assert(Subtarget.hasStdExtZbkb() && "Unexpected extension");
SDValue Src = N->getOperand(0);
if (Src.getOpcode() != ISD::BSWAP)
return SDValue();
EVT VT = N->getValueType(0);
if (!VT.isScalarInteger() || VT.getSizeInBits() >= Subtarget.getXLen() ||
!llvm::has_single_bit<uint32_t>(VT.getSizeInBits()))
return SDValue();
SDLoc DL(N);
return DAG.getNode(RISCVISD::BREV8, DL, VT, Src.getOperand(0));
}
// Convert from one FMA opcode to another based on whether we are negating the
// multiply result and/or the accumulator.
// NOTE: Only supports RVV operations with VL.
static unsigned negateFMAOpcode(unsigned Opcode, bool NegMul, bool NegAcc) {
assert((NegMul || NegAcc) && "Not negating anything?");
// Negating the multiply result changes ADD<->SUB and toggles 'N'.
if (NegMul) {
// clang-format off
switch (Opcode) {
default: llvm_unreachable("Unexpected opcode");
case RISCVISD::VFMADD_VL: Opcode = RISCVISD::VFNMSUB_VL; break;
case RISCVISD::VFNMSUB_VL: Opcode = RISCVISD::VFMADD_VL; break;
case RISCVISD::VFNMADD_VL: Opcode = RISCVISD::VFMSUB_VL; break;
case RISCVISD::VFMSUB_VL: Opcode = RISCVISD::VFNMADD_VL; break;
case RISCVISD::STRICT_VFMADD_VL: Opcode = RISCVISD::STRICT_VFNMSUB_VL; break;
case RISCVISD::STRICT_VFNMSUB_VL: Opcode = RISCVISD::STRICT_VFMADD_VL; break;
case RISCVISD::STRICT_VFNMADD_VL: Opcode = RISCVISD::STRICT_VFMSUB_VL; break;
case RISCVISD::STRICT_VFMSUB_VL: Opcode = RISCVISD::STRICT_VFNMADD_VL; break;
}
// clang-format on
}
// Negating the accumulator changes ADD<->SUB.
if (NegAcc) {
// clang-format off
switch (Opcode) {
default: llvm_unreachable("Unexpected opcode");
case RISCVISD::VFMADD_VL: Opcode = RISCVISD::VFMSUB_VL; break;
case RISCVISD::VFMSUB_VL: Opcode = RISCVISD::VFMADD_VL; break;
case RISCVISD::VFNMADD_VL: Opcode = RISCVISD::VFNMSUB_VL; break;
case RISCVISD::VFNMSUB_VL: Opcode = RISCVISD::VFNMADD_VL; break;
case RISCVISD::STRICT_VFMADD_VL: Opcode = RISCVISD::STRICT_VFMSUB_VL; break;
case RISCVISD::STRICT_VFMSUB_VL: Opcode = RISCVISD::STRICT_VFMADD_VL; break;
case RISCVISD::STRICT_VFNMADD_VL: Opcode = RISCVISD::STRICT_VFNMSUB_VL; break;
case RISCVISD::STRICT_VFNMSUB_VL: Opcode = RISCVISD::STRICT_VFNMADD_VL; break;
}
// clang-format on
}
return Opcode;
}
static SDValue performSRACombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
assert(N->getOpcode() == ISD::SRA && "Unexpected opcode");
if (N->getValueType(0) != MVT::i64 || !Subtarget.is64Bit())
return SDValue();
if (!isa<ConstantSDNode>(N->getOperand(1)))
return SDValue();
uint64_t ShAmt = N->getConstantOperandVal(1);
if (ShAmt > 32)
return SDValue();
SDValue N0 = N->getOperand(0);
// Combine (sra (sext_inreg (shl X, C1), i32), C2) ->
// (sra (shl X, C1+32), C2+32) so it gets selected as SLLI+SRAI instead of
// SLLIW+SRAIW. SLLI+SRAI have compressed forms.
if (ShAmt < 32 &&
N0.getOpcode() == ISD::SIGN_EXTEND_INREG && N0.hasOneUse() &&
cast<VTSDNode>(N0.getOperand(1))->getVT() == MVT::i32 &&
N0.getOperand(0).getOpcode() == ISD::SHL && N0.getOperand(0).hasOneUse() &&
isa<ConstantSDNode>(N0.getOperand(0).getOperand(1))) {
uint64_t LShAmt = N0.getOperand(0).getConstantOperandVal(1);
if (LShAmt < 32) {
SDLoc ShlDL(N0.getOperand(0));
SDValue Shl = DAG.getNode(ISD::SHL, ShlDL, MVT::i64,
N0.getOperand(0).getOperand(0),
DAG.getConstant(LShAmt + 32, ShlDL, MVT::i64));
SDLoc DL(N);
return DAG.getNode(ISD::SRA, DL, MVT::i64, Shl,
DAG.getConstant(ShAmt + 32, DL, MVT::i64));
}
}
// Combine (sra (shl X, 32), 32 - C) -> (shl (sext_inreg X, i32), C)
// FIXME: Should this be a generic combine? There's a similar combine on X86.
//
// Also try these folds where an add or sub is in the middle.
// (sra (add (shl X, 32), C1), 32 - C) -> (shl (sext_inreg (add X, C1), C)
// (sra (sub C1, (shl X, 32)), 32 - C) -> (shl (sext_inreg (sub C1, X), C)
SDValue Shl;
ConstantSDNode *AddC = nullptr;
// We might have an ADD or SUB between the SRA and SHL.
bool IsAdd = N0.getOpcode() == ISD::ADD;
if ((IsAdd || N0.getOpcode() == ISD::SUB)) {
// Other operand needs to be a constant we can modify.
AddC = dyn_cast<ConstantSDNode>(N0.getOperand(IsAdd ? 1 : 0));
if (!AddC)
return SDValue();
// AddC needs to have at least 32 trailing zeros.
if (AddC->getAPIntValue().countr_zero() < 32)
return SDValue();
// All users should be a shift by constant less than or equal to 32. This
// ensures we'll do this optimization for each of them to produce an
// add/sub+sext_inreg they can all share.
for (SDNode *U : N0->uses()) {
if (U->getOpcode() != ISD::SRA ||
!isa<ConstantSDNode>(U->getOperand(1)) ||
cast<ConstantSDNode>(U->getOperand(1))->getZExtValue() > 32)
return SDValue();
}
Shl = N0.getOperand(IsAdd ? 0 : 1);
} else {
// Not an ADD or SUB.
Shl = N0;
}
// Look for a shift left by 32.
if (Shl.getOpcode() != ISD::SHL || !isa<ConstantSDNode>(Shl.getOperand(1)) ||
Shl.getConstantOperandVal(1) != 32)
return SDValue();
// We if we didn't look through an add/sub, then the shl should have one use.
// If we did look through an add/sub, the sext_inreg we create is free so
// we're only creating 2 new instructions. It's enough to only remove the
// original sra+add/sub.
if (!AddC && !Shl.hasOneUse())
return SDValue();
SDLoc DL(N);
SDValue In = Shl.getOperand(0);
// If we looked through an ADD or SUB, we need to rebuild it with the shifted
// constant.
if (AddC) {
SDValue ShiftedAddC =
DAG.getConstant(AddC->getAPIntValue().lshr(32), DL, MVT::i64);
if (IsAdd)
In = DAG.getNode(ISD::ADD, DL, MVT::i64, In, ShiftedAddC);
else
In = DAG.getNode(ISD::SUB, DL, MVT::i64, ShiftedAddC, In);
}
SDValue SExt = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i64, In,
DAG.getValueType(MVT::i32));
if (ShAmt == 32)
return SExt;
return DAG.getNode(
ISD::SHL, DL, MVT::i64, SExt,
DAG.getConstant(32 - ShAmt, DL, MVT::i64));
}
// Invert (and/or (set cc X, Y), (xor Z, 1)) to (or/and (set !cc X, Y)), Z) if
// the result is used as the conditon of a br_cc or select_cc we can invert,
// inverting the setcc is free, and Z is 0/1. Caller will invert the
// br_cc/select_cc.
static SDValue tryDemorganOfBooleanCondition(SDValue Cond, SelectionDAG &DAG) {
bool IsAnd = Cond.getOpcode() == ISD::AND;
if (!IsAnd && Cond.getOpcode() != ISD::OR)
return SDValue();
if (!Cond.hasOneUse())
return SDValue();
SDValue Setcc = Cond.getOperand(0);
SDValue Xor = Cond.getOperand(1);
// Canonicalize setcc to LHS.
if (Setcc.getOpcode() != ISD::SETCC)
std::swap(Setcc, Xor);
// LHS should be a setcc and RHS should be an xor.
if (Setcc.getOpcode() != ISD::SETCC || !Setcc.hasOneUse() ||
Xor.getOpcode() != ISD::XOR || !Xor.hasOneUse())
return SDValue();
// If the condition is an And, SimplifyDemandedBits may have changed
// (xor Z, 1) to (not Z).
SDValue Xor1 = Xor.getOperand(1);
if (!isOneConstant(Xor1) && !(IsAnd && isAllOnesConstant(Xor1)))
return SDValue();
EVT VT = Cond.getValueType();
SDValue Xor0 = Xor.getOperand(0);
// The LHS of the xor needs to be 0/1.
APInt Mask = APInt::getBitsSetFrom(VT.getSizeInBits(), 1);
if (!DAG.MaskedValueIsZero(Xor0, Mask))
return SDValue();
// We can only invert integer setccs.
EVT SetCCOpVT = Setcc.getOperand(0).getValueType();
if (!SetCCOpVT.isScalarInteger())
return SDValue();
ISD::CondCode CCVal = cast<CondCodeSDNode>(Setcc.getOperand(2))->get();
if (ISD::isIntEqualitySetCC(CCVal)) {
CCVal = ISD::getSetCCInverse(CCVal, SetCCOpVT);
Setcc = DAG.getSetCC(SDLoc(Setcc), VT, Setcc.getOperand(0),
Setcc.getOperand(1), CCVal);
} else if (CCVal == ISD::SETLT && isNullConstant(Setcc.getOperand(0))) {
// Invert (setlt 0, X) by converting to (setlt X, 1).
Setcc = DAG.getSetCC(SDLoc(Setcc), VT, Setcc.getOperand(1),
DAG.getConstant(1, SDLoc(Setcc), VT), CCVal);
} else if (CCVal == ISD::SETLT && isOneConstant(Setcc.getOperand(1))) {
// (setlt X, 1) by converting to (setlt 0, X).
Setcc = DAG.getSetCC(SDLoc(Setcc), VT,
DAG.getConstant(0, SDLoc(Setcc), VT),
Setcc.getOperand(0), CCVal);
} else
return SDValue();
unsigned Opc = IsAnd ? ISD::OR : ISD::AND;
return DAG.getNode(Opc, SDLoc(Cond), VT, Setcc, Xor.getOperand(0));
}
// Perform common combines for BR_CC and SELECT_CC condtions.
static bool combine_CC(SDValue &LHS, SDValue &RHS, SDValue &CC, const SDLoc &DL,
SelectionDAG &DAG, const RISCVSubtarget &Subtarget) {
ISD::CondCode CCVal = cast<CondCodeSDNode>(CC)->get();
// As far as arithmetic right shift always saves the sign,
// shift can be omitted.
// Fold setlt (sra X, N), 0 -> setlt X, 0 and
// setge (sra X, N), 0 -> setge X, 0
if (auto *RHSConst = dyn_cast<ConstantSDNode>(RHS.getNode())) {
if ((CCVal == ISD::SETGE || CCVal == ISD::SETLT) &&
LHS.getOpcode() == ISD::SRA && RHSConst->isZero()) {
LHS = LHS.getOperand(0);
return true;
}
}
if (!ISD::isIntEqualitySetCC(CCVal))
return false;
// Fold ((setlt X, Y), 0, ne) -> (X, Y, lt)
// Sometimes the setcc is introduced after br_cc/select_cc has been formed.
if (LHS.getOpcode() == ISD::SETCC && isNullConstant(RHS) &&
LHS.getOperand(0).getValueType() == Subtarget.getXLenVT()) {
// If we're looking for eq 0 instead of ne 0, we need to invert the
// condition.
bool Invert = CCVal == ISD::SETEQ;
CCVal = cast<CondCodeSDNode>(LHS.getOperand(2))->get();
if (Invert)
CCVal = ISD::getSetCCInverse(CCVal, LHS.getValueType());
RHS = LHS.getOperand(1);
LHS = LHS.getOperand(0);
translateSetCCForBranch(DL, LHS, RHS, CCVal, DAG);
CC = DAG.getCondCode(CCVal);
return true;
}
// Fold ((xor X, Y), 0, eq/ne) -> (X, Y, eq/ne)
if (LHS.getOpcode() == ISD::XOR && isNullConstant(RHS)) {
RHS = LHS.getOperand(1);
LHS = LHS.getOperand(0);
return true;
}
// Fold ((srl (and X, 1<<C), C), 0, eq/ne) -> ((shl X, XLen-1-C), 0, ge/lt)
if (isNullConstant(RHS) && LHS.getOpcode() == ISD::SRL && LHS.hasOneUse() &&
LHS.getOperand(1).getOpcode() == ISD::Constant) {
SDValue LHS0 = LHS.getOperand(0);
if (LHS0.getOpcode() == ISD::AND &&
LHS0.getOperand(1).getOpcode() == ISD::Constant) {
uint64_t Mask = LHS0.getConstantOperandVal(1);
uint64_t ShAmt = LHS.getConstantOperandVal(1);
if (isPowerOf2_64(Mask) && Log2_64(Mask) == ShAmt) {
CCVal = CCVal == ISD::SETEQ ? ISD::SETGE : ISD::SETLT;
CC = DAG.getCondCode(CCVal);
ShAmt = LHS.getValueSizeInBits() - 1 - ShAmt;
LHS = LHS0.getOperand(0);
if (ShAmt != 0)
LHS =
DAG.getNode(ISD::SHL, DL, LHS.getValueType(), LHS0.getOperand(0),
DAG.getConstant(ShAmt, DL, LHS.getValueType()));
return true;
}
}
}
// (X, 1, setne) -> // (X, 0, seteq) if we can prove X is 0/1.
// This can occur when legalizing some floating point comparisons.
APInt Mask = APInt::getBitsSetFrom(LHS.getValueSizeInBits(), 1);
if (isOneConstant(RHS) && DAG.MaskedValueIsZero(LHS, Mask)) {
CCVal = ISD::getSetCCInverse(CCVal, LHS.getValueType());
CC = DAG.getCondCode(CCVal);
RHS = DAG.getConstant(0, DL, LHS.getValueType());
return true;
}
if (isNullConstant(RHS)) {
if (SDValue NewCond = tryDemorganOfBooleanCondition(LHS, DAG)) {
CCVal = ISD::getSetCCInverse(CCVal, LHS.getValueType());
CC = DAG.getCondCode(CCVal);
LHS = NewCond;
return true;
}
}
return false;
}
// Fold
// (select C, (add Y, X), Y) -> (add Y, (select C, X, 0)).
// (select C, (sub Y, X), Y) -> (sub Y, (select C, X, 0)).
// (select C, (or Y, X), Y) -> (or Y, (select C, X, 0)).
// (select C, (xor Y, X), Y) -> (xor Y, (select C, X, 0)).
static SDValue tryFoldSelectIntoOp(SDNode *N, SelectionDAG &DAG,
SDValue TrueVal, SDValue FalseVal,
bool Swapped) {
bool Commutative = true;
switch (TrueVal.getOpcode()) {
default:
return SDValue();
case ISD::SUB:
Commutative = false;
break;
case ISD::ADD:
case ISD::OR:
case ISD::XOR:
break;
}
if (!TrueVal.hasOneUse() || isa<ConstantSDNode>(FalseVal))
return SDValue();
unsigned OpToFold;
if (FalseVal == TrueVal.getOperand(0))
OpToFold = 0;
else if (Commutative && FalseVal == TrueVal.getOperand(1))
OpToFold = 1;
else
return SDValue();
EVT VT = N->getValueType(0);
SDLoc DL(N);
SDValue Zero = DAG.getConstant(0, DL, VT);
SDValue OtherOp = TrueVal.getOperand(1 - OpToFold);
if (Swapped)
std::swap(OtherOp, Zero);
SDValue NewSel = DAG.getSelect(DL, VT, N->getOperand(0), OtherOp, Zero);
return DAG.getNode(TrueVal.getOpcode(), DL, VT, FalseVal, NewSel);
}
static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
const RISCVSubtarget &Subtarget) {
if (Subtarget.hasShortForwardBranchOpt())
return SDValue();
// Only support XLenVT.
if (N->getValueType(0) != Subtarget.getXLenVT())
return SDValue();
SDValue TrueVal = N->getOperand(1);
SDValue FalseVal = N->getOperand(2);
if (SDValue V = tryFoldSelectIntoOp(N, DAG, TrueVal, FalseVal, /*Swapped*/false))
return V;
return tryFoldSelectIntoOp(N, DAG, FalseVal, TrueVal, /*Swapped*/true);
}
SDValue RISCVTargetLowering::PerformDAGCombine(SDNode *N,
DAGCombinerInfo &DCI) const {
SelectionDAG &DAG = DCI.DAG;
// Helper to call SimplifyDemandedBits on an operand of N where only some low
// bits are demanded. N will be added to the Worklist if it was not deleted.
// Caller should return SDValue(N, 0) if this returns true.
auto SimplifyDemandedLowBitsHelper = [&](unsigned OpNo, unsigned LowBits) {
SDValue Op = N->getOperand(OpNo);
APInt Mask = APInt::getLowBitsSet(Op.getValueSizeInBits(), LowBits);
if (!SimplifyDemandedBits(Op, Mask, DCI))
return false;
if (N->getOpcode() != ISD::DELETED_NODE)
DCI.AddToWorklist(N);
return true;
};
switch (N->getOpcode()) {
default:
break;
case RISCVISD::SplitF64: {
SDValue Op0 = N->getOperand(0);
// If the input to SplitF64 is just BuildPairF64 then the operation is
// redundant. Instead, use BuildPairF64's operands directly.
if (Op0->getOpcode() == RISCVISD::BuildPairF64)
return DCI.CombineTo(N, Op0.getOperand(0), Op0.getOperand(1));
if (Op0->isUndef()) {
SDValue Lo = DAG.getUNDEF(MVT::i32);
SDValue Hi = DAG.getUNDEF(MVT::i32);
return DCI.CombineTo(N, Lo, Hi);
}
SDLoc DL(N);
// It's cheaper to materialise two 32-bit integers than to load a double
// from the constant pool and transfer it to integer registers through the
// stack.
if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Op0)) {
APInt V = C->getValueAPF().bitcastToAPInt();
SDValue Lo = DAG.getConstant(V.trunc(32), DL, MVT::i32);
SDValue Hi = DAG.getConstant(V.lshr(32).trunc(32), DL, MVT::i32);
return DCI.CombineTo(N, Lo, Hi);
}
// This is a target-specific version of a DAGCombine performed in
// DAGCombiner::visitBITCAST. It performs the equivalent of:
// fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
// fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
if (!(Op0.getOpcode() == ISD::FNEG || Op0.getOpcode() == ISD::FABS) ||
!Op0.getNode()->hasOneUse())
break;
SDValue NewSplitF64 =
DAG.getNode(RISCVISD::SplitF64, DL, DAG.getVTList(MVT::i32, MVT::i32),
Op0.getOperand(0));
SDValue Lo = NewSplitF64.getValue(0);
SDValue Hi = NewSplitF64.getValue(1);
APInt SignBit = APInt::getSignMask(32);
if (Op0.getOpcode() == ISD::FNEG) {
SDValue NewHi = DAG.getNode(ISD::XOR, DL, MVT::i32, Hi,
DAG.getConstant(SignBit, DL, MVT::i32));
return DCI.CombineTo(N, Lo, NewHi);
}
assert(Op0.getOpcode() == ISD::FABS);
SDValue NewHi = DAG.getNode(ISD::AND, DL, MVT::i32, Hi,
DAG.getConstant(~SignBit, DL, MVT::i32));
return DCI.CombineTo(N, Lo, NewHi);
}
case RISCVISD::SLLW:
case RISCVISD::SRAW:
case RISCVISD::SRLW:
case RISCVISD::RORW:
case RISCVISD::ROLW: {
// Only the lower 32 bits of LHS and lower 5 bits of RHS are read.
if (SimplifyDemandedLowBitsHelper(0, 32) ||
SimplifyDemandedLowBitsHelper(1, 5))
return SDValue(N, 0);
break;
}
case RISCVISD::CLZW:
case RISCVISD::CTZW: {
// Only the lower 32 bits of the first operand are read
if (SimplifyDemandedLowBitsHelper(0, 32))
return SDValue(N, 0);
break;
}
case RISCVISD::FMV_X_ANYEXTH:
case RISCVISD::FMV_X_ANYEXTW_RV64: {
SDLoc DL(N);
SDValue Op0 = N->getOperand(0);
MVT VT = N->getSimpleValueType(0);
// If the input to FMV_X_ANYEXTW_RV64 is just FMV_W_X_RV64 then the
// conversion is unnecessary and can be replaced with the FMV_W_X_RV64
// operand. Similar for FMV_X_ANYEXTH and FMV_H_X.
if ((N->getOpcode() == RISCVISD::FMV_X_ANYEXTW_RV64 &&
Op0->getOpcode() == RISCVISD::FMV_W_X_RV64) ||
(N->getOpcode() == RISCVISD::FMV_X_ANYEXTH &&
Op0->getOpcode() == RISCVISD::FMV_H_X)) {
assert(Op0.getOperand(0).getValueType() == VT &&
"Unexpected value type!");
return Op0.getOperand(0);
}
// This is a target-specific version of a DAGCombine performed in
// DAGCombiner::visitBITCAST. It performs the equivalent of:
// fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
// fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
if (!(Op0.getOpcode() == ISD::FNEG || Op0.getOpcode() == ISD::FABS) ||
!Op0.getNode()->hasOneUse())
break;
SDValue NewFMV = DAG.getNode(N->getOpcode(), DL, VT, Op0.getOperand(0));
unsigned FPBits = N->getOpcode() == RISCVISD::FMV_X_ANYEXTW_RV64 ? 32 : 16;
APInt SignBit = APInt::getSignMask(FPBits).sext(VT.getSizeInBits());
if (Op0.getOpcode() == ISD::FNEG)
return DAG.getNode(ISD::XOR, DL, VT, NewFMV,
DAG.getConstant(SignBit, DL, VT));
assert(Op0.getOpcode() == ISD::FABS);
return DAG.getNode(ISD::AND, DL, VT, NewFMV,
DAG.getConstant(~SignBit, DL, VT));
}
case ISD::ADD:
return performADDCombine(N, DAG, Subtarget);
case ISD::SUB:
return performSUBCombine(N, DAG, Subtarget);
case ISD::AND:
return performANDCombine(N, DCI, Subtarget);
case ISD::OR:
return performORCombine(N, DCI, Subtarget);
case ISD::XOR:
return performXORCombine(N, DAG, Subtarget);
case ISD::FADD:
case ISD::UMAX:
case ISD::UMIN:
case ISD::SMAX:
case ISD::SMIN:
case ISD::FMAXNUM:
case ISD::FMINNUM:
return combineBinOpToReduce(N, DAG, Subtarget);
case ISD::SETCC:
return performSETCCCombine(N, DAG, Subtarget);
case ISD::SIGN_EXTEND_INREG:
return performSIGN_EXTEND_INREGCombine(N, DAG, Subtarget);
case ISD::ZERO_EXTEND:
// Fold (zero_extend (fp_to_uint X)) to prevent forming fcvt+zexti32 during
// type legalization. This is safe because fp_to_uint produces poison if
// it overflows.
if (N->getValueType(0) == MVT::i64 && Subtarget.is64Bit()) {
SDValue Src = N->getOperand(0);
if (Src.getOpcode() == ISD::FP_TO_UINT &&
isTypeLegal(Src.getOperand(0).getValueType()))
return DAG.getNode(ISD::FP_TO_UINT, SDLoc(N), MVT::i64,
Src.getOperand(0));
if (Src.getOpcode() == ISD::STRICT_FP_TO_UINT && Src.hasOneUse() &&
isTypeLegal(Src.getOperand(1).getValueType())) {
SDVTList VTs = DAG.getVTList(MVT::i64, MVT::Other);
SDValue Res = DAG.getNode(ISD::STRICT_FP_TO_UINT, SDLoc(N), VTs,
Src.getOperand(0), Src.getOperand(1));
DCI.CombineTo(N, Res);
DAG.ReplaceAllUsesOfValueWith(Src.getValue(1), Res.getValue(1));
DCI.recursivelyDeleteUnusedNodes(Src.getNode());
return SDValue(N, 0); // Return N so it doesn't get rechecked.
}
}
return SDValue();
case ISD::TRUNCATE:
return performTRUNCATECombine(N, DAG, Subtarget);
case ISD::SELECT:
return performSELECTCombine(N, DAG, Subtarget);
case RISCVISD::SELECT_CC: {
// Transform
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
SDValue CC = N->getOperand(2);
ISD::CondCode CCVal = cast<CondCodeSDNode>(CC)->get();
SDValue TrueV = N->getOperand(3);
SDValue FalseV = N->getOperand(4);
SDLoc DL(N);
EVT VT = N->getValueType(0);
// If the True and False values are the same, we don't need a select_cc.
if (TrueV == FalseV)
return TrueV;
// (select (x < 0), y, z) -> x >> (XLEN - 1) & (y - z) + z
// (select (x >= 0), y, z) -> x >> (XLEN - 1) & (z - y) + y
if (!Subtarget.hasShortForwardBranchOpt() && isa<ConstantSDNode>(TrueV) &&
isa<ConstantSDNode>(FalseV) && isNullConstant(RHS) &&
(CCVal == ISD::CondCode::SETLT || CCVal == ISD::CondCode::SETGE)) {
if (CCVal == ISD::CondCode::SETGE)
std::swap(TrueV, FalseV);
int64_t TrueSImm = cast<ConstantSDNode>(TrueV)->getSExtValue();
int64_t FalseSImm = cast<ConstantSDNode>(FalseV)->getSExtValue();
// Only handle simm12, if it is not in this range, it can be considered as
// register.
if (isInt<12>(TrueSImm) && isInt<12>(FalseSImm) &&
isInt<12>(TrueSImm - FalseSImm)) {
SDValue SRA =
DAG.getNode(ISD::SRA, DL, VT, LHS,
DAG.getConstant(Subtarget.getXLen() - 1, DL, VT));
SDValue AND =
DAG.getNode(ISD::AND, DL, VT, SRA,
DAG.getConstant(TrueSImm - FalseSImm, DL, VT));
return DAG.getNode(ISD::ADD, DL, VT, AND, FalseV);
}
if (CCVal == ISD::CondCode::SETGE)
std::swap(TrueV, FalseV);
}
if (combine_CC(LHS, RHS, CC, DL, DAG, Subtarget))
return DAG.getNode(RISCVISD::SELECT_CC, DL, N->getValueType(0),
{LHS, RHS, CC, TrueV, FalseV});
if (!Subtarget.hasShortForwardBranchOpt()) {
// (select c, -1, y) -> -c | y
if (isAllOnesConstant(TrueV)) {
SDValue C = DAG.getSetCC(DL, VT, LHS, RHS, CCVal);
SDValue Neg = DAG.getNegative(C, DL, VT);
return DAG.getNode(ISD::OR, DL, VT, Neg, FalseV);
}
// (select c, y, -1) -> -!c | y
if (isAllOnesConstant(FalseV)) {
SDValue C =
DAG.getSetCC(DL, VT, LHS, RHS, ISD::getSetCCInverse(CCVal, VT));
SDValue Neg = DAG.getNegative(C, DL, VT);
return DAG.getNode(ISD::OR, DL, VT, Neg, TrueV);
}
// (select c, 0, y) -> -!c & y
if (isNullConstant(TrueV)) {
SDValue C =
DAG.getSetCC(DL, VT, LHS, RHS, ISD::getSetCCInverse(CCVal, VT));
SDValue Neg = DAG.getNegative(C, DL, VT);
return DAG.getNode(ISD::AND, DL, VT, Neg, FalseV);
}
// (select c, y, 0) -> -c & y
if (isNullConstant(FalseV)) {
SDValue C = DAG.getSetCC(DL, VT, LHS, RHS, CCVal);
SDValue Neg = DAG.getNegative(C, DL, VT);
return DAG.getNode(ISD::AND, DL, VT, Neg, TrueV);
}
// (riscvisd::select_cc x, 0, ne, x, 1) -> (add x, (setcc x, 0, eq))
// (riscvisd::select_cc x, 0, eq, 1, x) -> (add x, (setcc x, 0, eq))
if (((isOneConstant(FalseV) && LHS == TrueV &&
CCVal == ISD::CondCode::SETNE) ||
(isOneConstant(TrueV) && LHS == FalseV &&
CCVal == ISD::CondCode::SETEQ)) &&
isNullConstant(RHS)) {
// freeze it to be safe.
LHS = DAG.getFreeze(LHS);
SDValue C = DAG.getSetCC(DL, VT, LHS, RHS, ISD::CondCode::SETEQ);
return DAG.getNode(ISD::ADD, DL, VT, LHS, C);
}
}
return SDValue();
}
case RISCVISD::BR_CC: {
SDValue LHS = N->getOperand(1);
SDValue RHS = N->getOperand(2);
SDValue CC = N->getOperand(3);
SDLoc DL(N);
if (combine_CC(LHS, RHS, CC, DL, DAG, Subtarget))
return DAG.getNode(RISCVISD::BR_CC, DL, N->getValueType(0),
N->getOperand(0), LHS, RHS, CC, N->getOperand(4));
return SDValue();
}
case ISD::BITREVERSE:
return performBITREVERSECombine(N, DAG, Subtarget);
case ISD::FP_TO_SINT:
case ISD::FP_TO_UINT:
return performFP_TO_INTCombine(N, DCI, Subtarget);
case ISD::FP_TO_SINT_SAT:
case ISD::FP_TO_UINT_SAT:
return performFP_TO_INT_SATCombine(N, DCI, Subtarget);
case ISD::FCOPYSIGN: {
EVT VT = N->getValueType(0);
if (!VT.isVector())
break;
// There is a form of VFSGNJ which injects the negated sign of its second
// operand. Try and bubble any FNEG up after the extend/round to produce
// this optimized pattern. Avoid modifying cases where FP_ROUND and
// TRUNC=1.
SDValue In2 = N->getOperand(1);
// Avoid cases where the extend/round has multiple uses, as duplicating
// those is typically more expensive than removing a fneg.
if (!In2.hasOneUse())
break;
if (In2.getOpcode() != ISD::FP_EXTEND &&
(In2.getOpcode() != ISD::FP_ROUND || In2.getConstantOperandVal(1) != 0))
break;
In2 = In2.getOperand(0);
if (In2.getOpcode() != ISD::FNEG)
break;
SDLoc DL(N);
SDValue NewFPExtRound = DAG.getFPExtendOrRound(In2.getOperand(0), DL, VT);
return DAG.getNode(ISD::FCOPYSIGN, DL, VT, N->getOperand(0),
DAG.getNode(ISD::FNEG, DL, VT, NewFPExtRound));
}
case ISD::MGATHER:
case ISD::MSCATTER:
case ISD::VP_GATHER:
case ISD::VP_SCATTER: {
if (!DCI.isBeforeLegalize())
break;
SDValue Index, ScaleOp;
bool IsIndexSigned = false;
if (const auto *VPGSN = dyn_cast<VPGatherScatterSDNode>(N)) {
Index = VPGSN->getIndex();
ScaleOp = VPGSN->getScale();
IsIndexSigned = VPGSN->isIndexSigned();
assert(!VPGSN->isIndexScaled() &&
"Scaled gather/scatter should not be formed");
} else {
const auto *MGSN = cast<MaskedGatherScatterSDNode>(N);
Index = MGSN->getIndex();
ScaleOp = MGSN->getScale();
IsIndexSigned = MGSN->isIndexSigned();
assert(!MGSN->isIndexScaled() &&
"Scaled gather/scatter should not be formed");
}
EVT IndexVT = Index.getValueType();
MVT XLenVT = Subtarget.getXLenVT();
// RISC-V indexed loads only support the "unsigned unscaled" addressing
// mode, so anything else must be manually legalized.
bool NeedsIdxLegalization =
(IsIndexSigned && IndexVT.getVectorElementType().bitsLT(XLenVT));
if (!NeedsIdxLegalization)
break;
SDLoc DL(N);
// Any index legalization should first promote to XLenVT, so we don't lose
// bits when scaling. This may create an illegal index type so we let
// LLVM's legalization take care of the splitting.
// FIXME: LLVM can't split VP_GATHER or VP_SCATTER yet.
if (IndexVT.getVectorElementType().bitsLT(XLenVT)) {
IndexVT = IndexVT.changeVectorElementType(XLenVT);
Index = DAG.getNode(IsIndexSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
DL, IndexVT, Index);
}
ISD::MemIndexType NewIndexTy = ISD::UNSIGNED_SCALED;
if (const auto *VPGN = dyn_cast<VPGatherSDNode>(N))
return DAG.getGatherVP(N->getVTList(), VPGN->getMemoryVT(), DL,
{VPGN->getChain(), VPGN->getBasePtr(), Index,
ScaleOp, VPGN->getMask(),
VPGN->getVectorLength()},
VPGN->getMemOperand(), NewIndexTy);
if (const auto *VPSN = dyn_cast<VPScatterSDNode>(N))
return DAG.getScatterVP(N->getVTList(), VPSN->getMemoryVT(), DL,
{VPSN->getChain(), VPSN->getValue(),
VPSN->getBasePtr(), Index, ScaleOp,
VPSN->getMask(), VPSN->getVectorLength()},
VPSN->getMemOperand(), NewIndexTy);
if (const auto *MGN = dyn_cast<MaskedGatherSDNode>(N))
return DAG.getMaskedGather(
N->getVTList(), MGN->getMemoryVT(), DL,
{MGN->getChain(), MGN->getPassThru(), MGN->getMask(),
MGN->getBasePtr(), Index, ScaleOp},
MGN->getMemOperand(), NewIndexTy, MGN->getExtensionType());
const auto *MSN = cast<MaskedScatterSDNode>(N);
return DAG.getMaskedScatter(
N->getVTList(), MSN->getMemoryVT(), DL,
{MSN->getChain(), MSN->getValue(), MSN->getMask(), MSN->getBasePtr(),
Index, ScaleOp},
MSN->getMemOperand(), NewIndexTy, MSN->isTruncatingStore());
}
case RISCVISD::SRA_VL:
case RISCVISD::SRL_VL:
case RISCVISD::SHL_VL: {
SDValue ShAmt = N->getOperand(1);
if (ShAmt.getOpcode() == RISCVISD::SPLAT_VECTOR_SPLIT_I64_VL) {
// We don't need the upper 32 bits of a 64-bit element for a shift amount.
SDLoc DL(N);
SDValue VL = N->getOperand(3);
EVT VT = N->getValueType(0);
ShAmt = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VT, DAG.getUNDEF(VT),
ShAmt.getOperand(1), VL);
return DAG.getNode(N->getOpcode(), DL, VT, N->getOperand(0), ShAmt,
N->getOperand(2), N->getOperand(3), N->getOperand(4));
}
break;
}
case ISD::SRA:
if (SDValue V = performSRACombine(N, DAG, Subtarget))
return V;
[[fallthrough]];
case ISD::SRL:
case ISD::SHL: {
SDValue ShAmt = N->getOperand(1);
if (ShAmt.getOpcode() == RISCVISD::SPLAT_VECTOR_SPLIT_I64_VL) {
// We don't need the upper 32 bits of a 64-bit element for a shift amount.
SDLoc DL(N);
EVT VT = N->getValueType(0);
ShAmt = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, VT, DAG.getUNDEF(VT),
ShAmt.getOperand(1),
DAG.getRegister(RISCV::X0, Subtarget.getXLenVT()));
return DAG.getNode(N->getOpcode(), DL, VT, N->getOperand(0), ShAmt);
}
break;
}
case RISCVISD::ADD_VL:
case RISCVISD::SUB_VL:
case RISCVISD::VWADD_W_VL:
case RISCVISD::VWADDU_W_VL:
case RISCVISD::VWSUB_W_VL:
case RISCVISD::VWSUBU_W_VL:
case RISCVISD::MUL_VL:
return combineBinOp_VLToVWBinOp_VL(N, DCI);
case RISCVISD::VFMADD_VL:
case RISCVISD::VFNMADD_VL:
case RISCVISD::VFMSUB_VL:
case RISCVISD::VFNMSUB_VL:
case RISCVISD::STRICT_VFMADD_VL:
case RISCVISD::STRICT_VFNMADD_VL:
case RISCVISD::STRICT_VFMSUB_VL:
case RISCVISD::STRICT_VFNMSUB_VL: {
// Fold FNEG_VL into FMA opcodes.
// The first operand of strict-fp is chain.
unsigned Offset = N->isTargetStrictFPOpcode();
SDValue A = N->getOperand(0 + Offset);
SDValue B = N->getOperand(1 + Offset);
SDValue C = N->getOperand(2 + Offset);
SDValue Mask = N->getOperand(3 + Offset);
SDValue VL = N->getOperand(4 + Offset);
auto invertIfNegative = [&Mask, &VL](SDValue &V) {
if (V.getOpcode() == RISCVISD::FNEG_VL && V.getOperand(1) == Mask &&
V.getOperand(2) == VL) {
// Return the negated input.
V = V.getOperand(0);
return true;
}
return false;
};
bool NegA = invertIfNegative(A);
bool NegB = invertIfNegative(B);
bool NegC = invertIfNegative(C);
// If no operands are negated, we're done.
if (!NegA && !NegB && !NegC)
return SDValue();
unsigned NewOpcode = negateFMAOpcode(N->getOpcode(), NegA != NegB, NegC);
if (Offset > 0)
return DAG.getNode(NewOpcode, SDLoc(N), N->getVTList(),
{N->getOperand(0), A, B, C, Mask, VL});
return DAG.getNode(NewOpcode, SDLoc(N), N->getValueType(0), A, B, C, Mask,
VL);
}
case ISD::LOAD:
case ISD::STORE: {
if (DCI.isAfterLegalizeDAG())
if (SDValue V = performMemPairCombine(N, DCI))
return V;
if (N->getOpcode() != ISD::STORE)
break;
auto *Store = cast<StoreSDNode>(N);
SDValue Val = Store->getValue();
// Combine store of vmv.x.s/vfmv.f.s to vse with VL of 1.
// vfmv.f.s is represented as extract element from 0. Match it late to avoid
// any illegal types.
if (Val.getOpcode() == RISCVISD::VMV_X_S ||
(DCI.isAfterLegalizeDAG() &&
Val.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
isNullConstant(Val.getOperand(1)))) {
SDValue Src = Val.getOperand(0);
MVT VecVT = Src.getSimpleValueType();
EVT MemVT = Store->getMemoryVT();
// VecVT should be scalable and memory VT should match the element type.
if (VecVT.isScalableVector() &&
MemVT == VecVT.getVectorElementType()) {
SDLoc DL(N);
MVT MaskVT = getMaskTypeFor(VecVT);
return DAG.getStoreVP(
Store->getChain(), DL, Src, Store->getBasePtr(), Store->getOffset(),
DAG.getConstant(1, DL, MaskVT),
DAG.getConstant(1, DL, Subtarget.getXLenVT()), MemVT,
Store->getMemOperand(), Store->getAddressingMode(),
Store->isTruncatingStore(), /*IsCompress*/ false);
}
}
break;
}
case ISD::SPLAT_VECTOR: {
EVT VT = N->getValueType(0);
// Only perform this combine on legal MVT types.
if (!isTypeLegal(VT))
break;
if (auto Gather = matchSplatAsGather(N->getOperand(0), VT.getSimpleVT(), N,
DAG, Subtarget))
return Gather;
break;
}
case RISCVISD::VMV_V_X_VL: {
// Tail agnostic VMV.V.X only demands the vector element bitwidth from the
// scalar input.
unsigned ScalarSize = N->getOperand(1).getValueSizeInBits();
unsigned EltWidth = N->getValueType(0).getScalarSizeInBits();
if (ScalarSize > EltWidth && N->getOperand(0).isUndef())
if (SimplifyDemandedLowBitsHelper(1, EltWidth))
return SDValue(N, 0);
break;
}
case RISCVISD::VFMV_S_F_VL: {
SDValue Src = N->getOperand(1);
// Try to remove vector->scalar->vector if the scalar->vector is inserting
// into an undef vector.
// TODO: Could use a vslide or vmv.v.v for non-undef.
if (N->getOperand(0).isUndef() &&
Src.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
isNullConstant(Src.getOperand(1)) &&
Src.getOperand(0).getValueType().isScalableVector()) {
EVT VT = N->getValueType(0);
EVT SrcVT = Src.getOperand(0).getValueType();
assert(SrcVT.getVectorElementType() == VT.getVectorElementType());
// Widths match, just return the original vector.
if (SrcVT == VT)
return Src.getOperand(0);
// TODO: Use insert_subvector/extract_subvector to change widen/narrow?
}
break;
}
case ISD::INTRINSIC_WO_CHAIN: {
unsigned IntNo = N->getConstantOperandVal(0);
switch (IntNo) {
// By default we do not combine any intrinsic.
default:
return SDValue();
case Intrinsic::riscv_vcpop:
case Intrinsic::riscv_vcpop_mask:
case Intrinsic::riscv_vfirst:
case Intrinsic::riscv_vfirst_mask: {
SDValue VL = N->getOperand(2);
if (IntNo == Intrinsic::riscv_vcpop_mask ||
IntNo == Intrinsic::riscv_vfirst_mask)
VL = N->getOperand(3);
if (!isNullConstant(VL))
return SDValue();
// If VL is 0, vcpop -> li 0, vfirst -> li -1.
SDLoc DL(N);
EVT VT = N->getValueType(0);
if (IntNo == Intrinsic::riscv_vfirst ||
IntNo == Intrinsic::riscv_vfirst_mask)
return DAG.getConstant(-1, DL, VT);
return DAG.getConstant(0, DL, VT);
}
}
}
case ISD::BITCAST: {
assert(Subtarget.useRVVForFixedLengthVectors());
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
EVT SrcVT = N0.getValueType();
// If this is a bitcast between a MVT::v4i1/v2i1/v1i1 and an illegal integer
// type, widen both sides to avoid a trip through memory.
if ((SrcVT == MVT::v1i1 || SrcVT == MVT::v2i1 || SrcVT == MVT::v4i1) &&
VT.isScalarInteger()) {
unsigned NumConcats = 8 / SrcVT.getVectorNumElements();
SmallVector<SDValue, 4> Ops(NumConcats, DAG.getUNDEF(SrcVT));
Ops[0] = N0;
SDLoc DL(N);
N0 = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v8i1, Ops);
N0 = DAG.getBitcast(MVT::i8, N0);
return DAG.getNode(ISD::TRUNCATE, DL, VT, N0);
}
return SDValue();
}
}
return SDValue();
}
bool RISCVTargetLowering::isDesirableToCommuteWithShift(
const SDNode *N, CombineLevel Level) const {
assert((N->getOpcode() == ISD::SHL || N->getOpcode() == ISD::SRA ||
N->getOpcode() == ISD::SRL) &&
"Expected shift op");
// The following folds are only desirable if `(OP _, c1 << c2)` can be
// materialised in fewer instructions than `(OP _, c1)`:
//
// (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2)
// (shl (or x, c1), c2) -> (or (shl x, c2), c1 << c2)
SDValue N0 = N->getOperand(0);
EVT Ty = N0.getValueType();
if (Ty.isScalarInteger() &&
(N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::OR)) {
auto *C1 = dyn_cast<ConstantSDNode>(N0->getOperand(1));
auto *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1));
if (C1 && C2) {
const APInt &C1Int = C1->getAPIntValue();
APInt ShiftedC1Int = C1Int << C2->getAPIntValue();
// We can materialise `c1 << c2` into an add immediate, so it's "free",
// and the combine should happen, to potentially allow further combines
// later.
if (ShiftedC1Int.getSignificantBits() <= 64 &&
isLegalAddImmediate(ShiftedC1Int.getSExtValue()))
return true;
// We can materialise `c1` in an add immediate, so it's "free", and the
// combine should be prevented.
if (C1Int.getSignificantBits() <= 64 &&
isLegalAddImmediate(C1Int.getSExtValue()))
return false;
// Neither constant will fit into an immediate, so find materialisation
// costs.
int C1Cost = RISCVMatInt::getIntMatCost(C1Int, Ty.getSizeInBits(),
Subtarget.getFeatureBits(),
/*CompressionCost*/true);
int ShiftedC1Cost = RISCVMatInt::getIntMatCost(
ShiftedC1Int, Ty.getSizeInBits(), Subtarget.getFeatureBits(),
/*CompressionCost*/true);
// Materialising `c1` is cheaper than materialising `c1 << c2`, so the
// combine should be prevented.
if (C1Cost < ShiftedC1Cost)
return false;
}
}
return true;
}
bool RISCVTargetLowering::targetShrinkDemandedConstant(
SDValue Op, const APInt &DemandedBits, const APInt &DemandedElts,
TargetLoweringOpt &TLO) const {
// Delay this optimization as late as possible.
if (!TLO.LegalOps)
return false;
EVT VT = Op.getValueType();
if (VT.isVector())
return false;
unsigned Opcode = Op.getOpcode();
if (Opcode != ISD::AND && Opcode != ISD::OR && Opcode != ISD::XOR)
return false;
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
if (!C)
return false;
const APInt &Mask = C->getAPIntValue();
// Clear all non-demanded bits initially.
APInt ShrunkMask = Mask & DemandedBits;
// Try to make a smaller immediate by setting undemanded bits.
APInt ExpandedMask = Mask | ~DemandedBits;
auto IsLegalMask = [ShrunkMask, ExpandedMask](const APInt &Mask) -> bool {
return ShrunkMask.isSubsetOf(Mask) && Mask.isSubsetOf(ExpandedMask);
};
auto UseMask = [Mask, Op, &TLO](const APInt &NewMask) -> bool {
if (NewMask == Mask)
return true;
SDLoc DL(Op);
SDValue NewC = TLO.DAG.getConstant(NewMask, DL, Op.getValueType());
SDValue NewOp = TLO.DAG.getNode(Op.getOpcode(), DL, Op.getValueType(),
Op.getOperand(0), NewC);
return TLO.CombineTo(Op, NewOp);
};
// If the shrunk mask fits in sign extended 12 bits, let the target
// independent code apply it.
if (ShrunkMask.isSignedIntN(12))
return false;
// And has a few special cases for zext.
if (Opcode == ISD::AND) {
// Preserve (and X, 0xffff), if zext.h exists use zext.h,
// otherwise use SLLI + SRLI.
APInt NewMask = APInt(Mask.getBitWidth(), 0xffff);
if (IsLegalMask(NewMask))
return UseMask(NewMask);
// Try to preserve (and X, 0xffffffff), the (zext_inreg X, i32) pattern.
if (VT == MVT::i64) {
APInt NewMask = APInt(64, 0xffffffff);
if (IsLegalMask(NewMask))
return UseMask(NewMask);
}
}
// For the remaining optimizations, we need to be able to make a negative
// number through a combination of mask and undemanded bits.
if (!ExpandedMask.isNegative())
return false;
// What is the fewest number of bits we need to represent the negative number.
unsigned MinSignedBits = ExpandedMask.getSignificantBits();
// Try to make a 12 bit negative immediate. If that fails try to make a 32
// bit negative immediate unless the shrunk immediate already fits in 32 bits.
// If we can't create a simm12, we shouldn't change opaque constants.
APInt NewMask = ShrunkMask;
if (MinSignedBits <= 12)
NewMask.setBitsFrom(11);
else if (!C->isOpaque() && MinSignedBits <= 32 && !ShrunkMask.isSignedIntN(32))
NewMask.setBitsFrom(31);
else
return false;
// Check that our new mask is a subset of the demanded mask.
assert(IsLegalMask(NewMask));
return UseMask(NewMask);
}
static uint64_t computeGREVOrGORC(uint64_t x, unsigned ShAmt, bool IsGORC) {
static const uint64_t GREVMasks[] = {
0x5555555555555555ULL, 0x3333333333333333ULL, 0x0F0F0F0F0F0F0F0FULL,
0x00FF00FF00FF00FFULL, 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL};
for (unsigned Stage = 0; Stage != 6; ++Stage) {
unsigned Shift = 1 << Stage;
if (ShAmt & Shift) {
uint64_t Mask = GREVMasks[Stage];
uint64_t Res = ((x & Mask) << Shift) | ((x >> Shift) & Mask);
if (IsGORC)
Res |= x;
x = Res;
}
}
return x;
}
void RISCVTargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
KnownBits &Known,
const APInt &DemandedElts,
const SelectionDAG &DAG,
unsigned Depth) const {
unsigned BitWidth = Known.getBitWidth();
unsigned Opc = Op.getOpcode();
assert((Opc >= ISD::BUILTIN_OP_END ||
Opc == ISD::INTRINSIC_WO_CHAIN ||
Opc == ISD::INTRINSIC_W_CHAIN ||
Opc == ISD::INTRINSIC_VOID) &&
"Should use MaskedValueIsZero if you don't know whether Op"
" is a target node!");
Known.resetAll();
switch (Opc) {
default: break;
case RISCVISD::SELECT_CC: {
Known = DAG.computeKnownBits(Op.getOperand(4), Depth + 1);
// If we don't know any bits, early out.
if (Known.isUnknown())
break;
KnownBits Known2 = DAG.computeKnownBits(Op.getOperand(3), Depth + 1);
// Only known if known in both the LHS and RHS.
Known = KnownBits::commonBits(Known, Known2);
break;
}
case RISCVISD::REMUW: {
KnownBits Known2;
Known = DAG.computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1);
Known2 = DAG.computeKnownBits(Op.getOperand(1), DemandedElts, Depth + 1);
// We only care about the lower 32 bits.
Known = KnownBits::urem(Known.trunc(32), Known2.trunc(32));
// Restore the original width by sign extending.
Known = Known.sext(BitWidth);
break;
}
case RISCVISD::DIVUW: {
KnownBits Known2;
Known = DAG.computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1);
Known2 = DAG.computeKnownBits(Op.getOperand(1), DemandedElts, Depth + 1);
// We only care about the lower 32 bits.
Known = KnownBits::udiv(Known.trunc(32), Known2.trunc(32));
// Restore the original width by sign extending.
Known = Known.sext(BitWidth);
break;
}
case RISCVISD::CTZW: {
KnownBits Known2 = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
unsigned PossibleTZ = Known2.trunc(32).countMaxTrailingZeros();
unsigned LowBits = llvm::bit_width(PossibleTZ);
Known.Zero.setBitsFrom(LowBits);
break;
}
case RISCVISD::CLZW: {
KnownBits Known2 = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
unsigned PossibleLZ = Known2.trunc(32).countMaxLeadingZeros();
unsigned LowBits = llvm::bit_width(PossibleLZ);
Known.Zero.setBitsFrom(LowBits);
break;
}
case RISCVISD::BREV8:
case RISCVISD::ORC_B: {
// FIXME: This is based on the non-ratified Zbp GREV and GORC where a
// control value of 7 is equivalent to brev8 and orc.b.
Known = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
bool IsGORC = Op.getOpcode() == RISCVISD::ORC_B;
// To compute zeros, we need to invert the value and invert it back after.
Known.Zero =
~computeGREVOrGORC(~Known.Zero.getZExtValue(), 7, IsGORC);
Known.One = computeGREVOrGORC(Known.One.getZExtValue(), 7, IsGORC);
break;
}
case RISCVISD::READ_VLENB: {
// We can use the minimum and maximum VLEN values to bound VLENB. We
// know VLEN must be a power of two.
const unsigned MinVLenB = Subtarget.getRealMinVLen() / 8;
const unsigned MaxVLenB = Subtarget.getRealMaxVLen() / 8;
assert(MinVLenB > 0 && "READ_VLENB without vector extension enabled?");
Known.Zero.setLowBits(Log2_32(MinVLenB));
Known.Zero.setBitsFrom(Log2_32(MaxVLenB)+1);
if (MaxVLenB == MinVLenB)
Known.One.setBit(Log2_32(MinVLenB));
break;
}
case ISD::INTRINSIC_W_CHAIN:
case ISD::INTRINSIC_WO_CHAIN: {
unsigned IntNo =
Op.getConstantOperandVal(Opc == ISD::INTRINSIC_WO_CHAIN ? 0 : 1);
switch (IntNo) {
default:
// We can't do anything for most intrinsics.
break;
case Intrinsic::riscv_vsetvli:
case Intrinsic::riscv_vsetvlimax:
// Assume that VL output is >= 65536.
// TODO: Take SEW and LMUL into account.
if (BitWidth > 17)
Known.Zero.setBitsFrom(17);
break;
}
break;
}
}
}
unsigned RISCVTargetLowering::ComputeNumSignBitsForTargetNode(
SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
unsigned Depth) const {
switch (Op.getOpcode()) {
default:
break;
case RISCVISD::SELECT_CC: {
unsigned Tmp =
DAG.ComputeNumSignBits(Op.getOperand(3), DemandedElts, Depth + 1);
if (Tmp == 1) return 1; // Early out.
unsigned Tmp2 =
DAG.ComputeNumSignBits(Op.getOperand(4), DemandedElts, Depth + 1);
return std::min(Tmp, Tmp2);
}
case RISCVISD::ABSW: {
// We expand this at isel to negw+max. The result will have 33 sign bits
// if the input has at least 33 sign bits.
unsigned Tmp =
DAG.ComputeNumSignBits(Op.getOperand(0), DemandedElts, Depth + 1);
if (Tmp < 33) return 1;
return 33;
}
case RISCVISD::SLLW:
case RISCVISD::SRAW:
case RISCVISD::SRLW:
case RISCVISD::DIVW:
case RISCVISD::DIVUW:
case RISCVISD::REMUW:
case RISCVISD::ROLW:
case RISCVISD::RORW:
case RISCVISD::FCVT_W_RV64:
case RISCVISD::FCVT_WU_RV64:
case RISCVISD::STRICT_FCVT_W_RV64:
case RISCVISD::STRICT_FCVT_WU_RV64:
// TODO: As the result is sign-extended, this is conservatively correct. A
// more precise answer could be calculated for SRAW depending on known
// bits in the shift amount.
return 33;
case RISCVISD::VMV_X_S: {
// The number of sign bits of the scalar result is computed by obtaining the
// element type of the input vector operand, subtracting its width from the
// XLEN, and then adding one (sign bit within the element type). If the
// element type is wider than XLen, the least-significant XLEN bits are
// taken.
unsigned XLen = Subtarget.getXLen();
unsigned EltBits = Op.getOperand(0).getScalarValueSizeInBits();
if (EltBits <= XLen)
return XLen - EltBits + 1;
break;
}
case ISD::INTRINSIC_W_CHAIN: {
unsigned IntNo = Op.getConstantOperandVal(1);
switch (IntNo) {
default:
break;
case Intrinsic::riscv_masked_atomicrmw_xchg_i64:
case Intrinsic::riscv_masked_atomicrmw_add_i64:
case Intrinsic::riscv_masked_atomicrmw_sub_i64:
case Intrinsic::riscv_masked_atomicrmw_nand_i64:
case Intrinsic::riscv_masked_atomicrmw_max_i64:
case Intrinsic::riscv_masked_atomicrmw_min_i64:
case Intrinsic::riscv_masked_atomicrmw_umax_i64:
case Intrinsic::riscv_masked_atomicrmw_umin_i64:
case Intrinsic::riscv_masked_cmpxchg_i64:
// riscv_masked_{atomicrmw_*,cmpxchg} intrinsics represent an emulated
// narrow atomic operation. These are implemented using atomic
// operations at the minimum supported atomicrmw/cmpxchg width whose
// result is then sign extended to XLEN. With +A, the minimum width is
// 32 for both 64 and 32.
assert(Subtarget.getXLen() == 64);
assert(getMinCmpXchgSizeInBits() == 32);
assert(Subtarget.hasStdExtA());
return 33;
}
}
}
return 1;
}
const Constant *
RISCVTargetLowering::getTargetConstantFromLoad(LoadSDNode *Ld) const {
assert(Ld && "Unexpected null LoadSDNode");
if (!ISD::isNormalLoad(Ld))
return nullptr;
SDValue Ptr = Ld->getBasePtr();
// Only constant pools with no offset are supported.
auto GetSupportedConstantPool = [](SDValue Ptr) -> ConstantPoolSDNode * {
auto *CNode = dyn_cast<ConstantPoolSDNode>(Ptr);
if (!CNode || CNode->isMachineConstantPoolEntry() ||
CNode->getOffset() != 0)
return nullptr;
return CNode;
};
// Simple case, LLA.
if (Ptr.getOpcode() == RISCVISD::LLA) {
auto *CNode = GetSupportedConstantPool(Ptr);
if (!CNode || CNode->getTargetFlags() != 0)
return nullptr;
return CNode->getConstVal();
}
// Look for a HI and ADD_LO pair.
if (Ptr.getOpcode() != RISCVISD::ADD_LO ||
Ptr.getOperand(0).getOpcode() != RISCVISD::HI)
return nullptr;
auto *CNodeLo = GetSupportedConstantPool(Ptr.getOperand(1));
auto *CNodeHi = GetSupportedConstantPool(Ptr.getOperand(0).getOperand(0));
if (!CNodeLo || CNodeLo->getTargetFlags() != RISCVII::MO_LO ||
!CNodeHi || CNodeHi->getTargetFlags() != RISCVII::MO_HI)
return nullptr;
if (CNodeLo->getConstVal() != CNodeHi->getConstVal())
return nullptr;
return CNodeLo->getConstVal();
}
static MachineBasicBlock *emitReadCycleWidePseudo(MachineInstr &MI,
MachineBasicBlock *BB) {
assert(MI.getOpcode() == RISCV::ReadCycleWide && "Unexpected instruction");
// To read the 64-bit cycle CSR on a 32-bit target, we read the two halves.
// Should the count have wrapped while it was being read, we need to try
// again.
// ...
// read:
// rdcycleh x3 # load high word of cycle
// rdcycle x2 # load low word of cycle
// rdcycleh x4 # load high word of cycle
// bne x3, x4, read # check if high word reads match, otherwise try again
// ...
MachineFunction &MF = *BB->getParent();
const BasicBlock *LLVM_BB = BB->getBasicBlock();
MachineFunction::iterator It = ++BB->getIterator();
MachineBasicBlock *LoopMBB = MF.CreateMachineBasicBlock(LLVM_BB);
MF.insert(It, LoopMBB);
MachineBasicBlock *DoneMBB = MF.CreateMachineBasicBlock(LLVM_BB);
MF.insert(It, DoneMBB);
// Transfer the remainder of BB and its successor edges to DoneMBB.
DoneMBB->splice(DoneMBB->begin(), BB,
std::next(MachineBasicBlock::iterator(MI)), BB->end());
DoneMBB->transferSuccessorsAndUpdatePHIs(BB);
BB->addSuccessor(LoopMBB);
MachineRegisterInfo &RegInfo = MF.getRegInfo();
Register ReadAgainReg = RegInfo.createVirtualRegister(&RISCV::GPRRegClass);
Register LoReg = MI.getOperand(0).getReg();
Register HiReg = MI.getOperand(1).getReg();
DebugLoc DL = MI.getDebugLoc();
const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
BuildMI(LoopMBB, DL, TII->get(RISCV::CSRRS), HiReg)
.addImm(RISCVSysReg::lookupSysRegByName("CYCLEH")->Encoding)
.addReg(RISCV::X0);
BuildMI(LoopMBB, DL, TII->get(RISCV::CSRRS), LoReg)
.addImm(RISCVSysReg::lookupSysRegByName("CYCLE")->Encoding)
.addReg(RISCV::X0);
BuildMI(LoopMBB, DL, TII->get(RISCV::CSRRS), ReadAgainReg)
.addImm(RISCVSysReg::lookupSysRegByName("CYCLEH")->Encoding)
.addReg(RISCV::X0);
BuildMI(LoopMBB, DL, TII->get(RISCV::BNE))
.addReg(HiReg)
.addReg(ReadAgainReg)
.addMBB(LoopMBB);
LoopMBB->addSuccessor(LoopMBB);
LoopMBB->addSuccessor(DoneMBB);
MI.eraseFromParent();
return DoneMBB;
}
static MachineBasicBlock *emitSplitF64Pseudo(MachineInstr &MI,
MachineBasicBlock *BB,
const RISCVSubtarget &Subtarget) {
assert(MI.getOpcode() == RISCV::SplitF64Pseudo && "Unexpected instruction");
MachineFunction &MF = *BB->getParent();
DebugLoc DL = MI.getDebugLoc();
const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
const TargetRegisterInfo *RI = MF.getSubtarget().getRegisterInfo();
Register LoReg = MI.getOperand(0).getReg();
Register HiReg = MI.getOperand(1).getReg();
Register SrcReg = MI.getOperand(2).getReg();
const TargetRegisterClass *SrcRC = &RISCV::FPR64RegClass;
int FI = MF.getInfo<RISCVMachineFunctionInfo>()->getMoveF64FrameIndex(MF);
TII.storeRegToStackSlot(*BB, MI, SrcReg, MI.getOperand(2).isKill(), FI, SrcRC,
RI, Register());
MachinePointerInfo MPI = MachinePointerInfo::getFixedStack(MF, FI);
MachineMemOperand *MMOLo =
MF.getMachineMemOperand(MPI, MachineMemOperand::MOLoad, 4, Align(8));
MachineMemOperand *MMOHi = MF.getMachineMemOperand(
MPI.getWithOffset(4), MachineMemOperand::MOLoad, 4, Align(8));
BuildMI(*BB, MI, DL, TII.get(RISCV::LW), LoReg)
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMOLo);
BuildMI(*BB, MI, DL, TII.get(RISCV::LW), HiReg)
.addFrameIndex(FI)
.addImm(4)
.addMemOperand(MMOHi);
MI.eraseFromParent(); // The pseudo instruction is gone now.
return BB;
}
static MachineBasicBlock *emitBuildPairF64Pseudo(MachineInstr &MI,
MachineBasicBlock *BB,
const RISCVSubtarget &Subtarget) {
assert(MI.getOpcode() == RISCV::BuildPairF64Pseudo &&
"Unexpected instruction");
MachineFunction &MF = *BB->getParent();
DebugLoc DL = MI.getDebugLoc();
const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
const TargetRegisterInfo *RI = MF.getSubtarget().getRegisterInfo();
Register DstReg = MI.getOperand(0).getReg();
Register LoReg = MI.getOperand(1).getReg();
Register HiReg = MI.getOperand(2).getReg();
const TargetRegisterClass *DstRC = &RISCV::FPR64RegClass;
int FI = MF.getInfo<RISCVMachineFunctionInfo>()->getMoveF64FrameIndex(MF);
MachinePointerInfo MPI = MachinePointerInfo::getFixedStack(MF, FI);
MachineMemOperand *MMOLo =
MF.getMachineMemOperand(MPI, MachineMemOperand::MOStore, 4, Align(8));
MachineMemOperand *MMOHi = MF.getMachineMemOperand(
MPI.getWithOffset(4), MachineMemOperand::MOStore, 4, Align(8));
BuildMI(*BB, MI, DL, TII.get(RISCV::SW))
.addReg(LoReg, getKillRegState(MI.getOperand(1).isKill()))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMOLo);
BuildMI(*BB, MI, DL, TII.get(RISCV::SW))
.addReg(HiReg, getKillRegState(MI.getOperand(2).isKill()))
.addFrameIndex(FI)
.addImm(4)
.addMemOperand(MMOHi);
TII.loadRegFromStackSlot(*BB, MI, DstReg, FI, DstRC, RI, Register());
MI.eraseFromParent(); // The pseudo instruction is gone now.
return BB;
}
static bool isSelectPseudo(MachineInstr &MI) {
switch (MI.getOpcode()) {
default:
return false;
case RISCV::Select_GPR_Using_CC_GPR:
case RISCV::Select_FPR16_Using_CC_GPR:
case RISCV::Select_FPR32_Using_CC_GPR:
case RISCV::Select_FPR64_Using_CC_GPR:
return true;
}
}
static MachineBasicBlock *emitQuietFCMP(MachineInstr &MI, MachineBasicBlock *BB,
unsigned RelOpcode, unsigned EqOpcode,
const RISCVSubtarget &Subtarget) {
DebugLoc DL = MI.getDebugLoc();
Register DstReg = MI.getOperand(0).getReg();
Register Src1Reg = MI.getOperand(1).getReg();
Register Src2Reg = MI.getOperand(2).getReg();
MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
Register SavedFFlags = MRI.createVirtualRegister(&RISCV::GPRRegClass);
const TargetInstrInfo &TII = *BB->getParent()->getSubtarget().getInstrInfo();
// Save the current FFLAGS.
BuildMI(*BB, MI, DL, TII.get(RISCV::ReadFFLAGS), SavedFFlags);
auto MIB = BuildMI(*BB, MI, DL, TII.get(RelOpcode), DstReg)
.addReg(Src1Reg)
.addReg(Src2Reg);
if (MI.getFlag(MachineInstr::MIFlag::NoFPExcept))
MIB->setFlag(MachineInstr::MIFlag::NoFPExcept);
// Restore the FFLAGS.
BuildMI(*BB, MI, DL, TII.get(RISCV::WriteFFLAGS))
.addReg(SavedFFlags, RegState::Kill);
// Issue a dummy FEQ opcode to raise exception for signaling NaNs.
auto MIB2 = BuildMI(*BB, MI, DL, TII.get(EqOpcode), RISCV::X0)
.addReg(Src1Reg, getKillRegState(MI.getOperand(1).isKill()))
.addReg(Src2Reg, getKillRegState(MI.getOperand(2).isKill()));
if (MI.getFlag(MachineInstr::MIFlag::NoFPExcept))
MIB2->setFlag(MachineInstr::MIFlag::NoFPExcept);
// Erase the pseudoinstruction.
MI.eraseFromParent();
return BB;
}
static MachineBasicBlock *
EmitLoweredCascadedSelect(MachineInstr &First, MachineInstr &Second,
MachineBasicBlock *ThisMBB,
const RISCVSubtarget &Subtarget) {
// Select_FPRX_ (rs1, rs2, imm, rs4, (Select_FPRX_ rs1, rs2, imm, rs4, rs5)
// Without this, custom-inserter would have generated:
//
// A
// | \
// | B
// | /
// C
// | \
// | D
// | /
// E
//
// A: X = ...; Y = ...
// B: empty
// C: Z = PHI [X, A], [Y, B]
// D: empty
// E: PHI [X, C], [Z, D]
//
// If we lower both Select_FPRX_ in a single step, we can instead generate:
//
// A
// | \
// | C
// | /|
// |/ |
// | |
// | D
// | /
// E
//
// A: X = ...; Y = ...
// D: empty
// E: PHI [X, A], [X, C], [Y, D]
const RISCVInstrInfo &TII = *Subtarget.getInstrInfo();
const DebugLoc &DL = First.getDebugLoc();
const BasicBlock *LLVM_BB = ThisMBB->getBasicBlock();
MachineFunction *F = ThisMBB->getParent();
MachineBasicBlock *FirstMBB = F->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *SecondMBB = F->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *SinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
MachineFunction::iterator It = ++ThisMBB->getIterator();
F->insert(It, FirstMBB);
F->insert(It, SecondMBB);
F->insert(It, SinkMBB);
// Transfer the remainder of ThisMBB and its successor edges to SinkMBB.
SinkMBB->splice(SinkMBB->begin(), ThisMBB,
std::next(MachineBasicBlock::iterator(First)),
ThisMBB->end());
SinkMBB->transferSuccessorsAndUpdatePHIs(ThisMBB);
// Fallthrough block for ThisMBB.
ThisMBB->addSuccessor(FirstMBB);
// Fallthrough block for FirstMBB.
FirstMBB->addSuccessor(SecondMBB);
ThisMBB->addSuccessor(SinkMBB);
FirstMBB->addSuccessor(SinkMBB);
// This is fallthrough.
SecondMBB->addSuccessor(SinkMBB);
auto FirstCC = static_cast<RISCVCC::CondCode>(First.getOperand(3).getImm());
Register FLHS = First.getOperand(1).getReg();
Register FRHS = First.getOperand(2).getReg();
// Insert appropriate branch.
BuildMI(FirstMBB, DL, TII.getBrCond(FirstCC))
.addReg(FLHS)
.addReg(FRHS)
.addMBB(SinkMBB);
Register SLHS = Second.getOperand(1).getReg();
Register SRHS = Second.getOperand(2).getReg();
Register Op1Reg4 = First.getOperand(4).getReg();
Register Op1Reg5 = First.getOperand(5).getReg();
auto SecondCC = static_cast<RISCVCC::CondCode>(Second.getOperand(3).getImm());
// Insert appropriate branch.
BuildMI(ThisMBB, DL, TII.getBrCond(SecondCC))
.addReg(SLHS)
.addReg(SRHS)
.addMBB(SinkMBB);
Register DestReg = Second.getOperand(0).getReg();
Register Op2Reg4 = Second.getOperand(4).getReg();
BuildMI(*SinkMBB, SinkMBB->begin(), DL, TII.get(RISCV::PHI), DestReg)
.addReg(Op2Reg4)
.addMBB(ThisMBB)
.addReg(Op1Reg4)
.addMBB(FirstMBB)
.addReg(Op1Reg5)
.addMBB(SecondMBB);
// Now remove the Select_FPRX_s.
First.eraseFromParent();
Second.eraseFromParent();
return SinkMBB;
}
static MachineBasicBlock *emitSelectPseudo(MachineInstr &MI,
MachineBasicBlock *BB,
const RISCVSubtarget &Subtarget) {
// To "insert" Select_* instructions, we actually have to insert the triangle
// control-flow pattern. The incoming instructions know the destination vreg
// to set, the condition code register to branch on, the true/false values to
// select between, and the condcode to use to select the appropriate branch.
//
// We produce the following control flow:
// HeadMBB
// | \
// | IfFalseMBB
// | /
// TailMBB
//
// When we find a sequence of selects we attempt to optimize their emission
// by sharing the control flow. Currently we only handle cases where we have
// multiple selects with the exact same condition (same LHS, RHS and CC).
// The selects may be interleaved with other instructions if the other
// instructions meet some requirements we deem safe:
// - They are not pseudo instructions.
// - They are debug instructions. Otherwise,
// - They do not have side-effects, do not access memory and their inputs do
// not depend on the results of the select pseudo-instructions.
// The TrueV/FalseV operands of the selects cannot depend on the result of
// previous selects in the sequence.
// These conditions could be further relaxed. See the X86 target for a
// related approach and more information.
//
// Select_FPRX_ (rs1, rs2, imm, rs4, (Select_FPRX_ rs1, rs2, imm, rs4, rs5))
// is checked here and handled by a separate function -
// EmitLoweredCascadedSelect.
Register LHS = MI.getOperand(1).getReg();
Register RHS = MI.getOperand(2).getReg();
auto CC = static_cast<RISCVCC::CondCode>(MI.getOperand(3).getImm());
SmallVector<MachineInstr *, 4> SelectDebugValues;
SmallSet<Register, 4> SelectDests;
SelectDests.insert(MI.getOperand(0).getReg());
MachineInstr *LastSelectPseudo = &MI;
auto Next = next_nodbg(MI.getIterator(), BB->instr_end());
if (MI.getOpcode() != RISCV::Select_GPR_Using_CC_GPR && Next != BB->end() &&
Next->getOpcode() == MI.getOpcode() &&
Next->getOperand(5).getReg() == MI.getOperand(0).getReg() &&
Next->getOperand(5).isKill()) {
return EmitLoweredCascadedSelect(MI, *Next, BB, Subtarget);
}
for (auto E = BB->end(), SequenceMBBI = MachineBasicBlock::iterator(MI);
SequenceMBBI != E; ++SequenceMBBI) {
if (SequenceMBBI->isDebugInstr())
continue;
if (isSelectPseudo(*SequenceMBBI)) {
if (SequenceMBBI->getOperand(1).getReg() != LHS ||
SequenceMBBI->getOperand(2).getReg() != RHS ||
SequenceMBBI->getOperand(3).getImm() != CC ||
SelectDests.count(SequenceMBBI->getOperand(4).getReg()) ||
SelectDests.count(SequenceMBBI->getOperand(5).getReg()))
break;
LastSelectPseudo = &*SequenceMBBI;
SequenceMBBI->collectDebugValues(SelectDebugValues);
SelectDests.insert(SequenceMBBI->getOperand(0).getReg());
continue;
}
if (SequenceMBBI->hasUnmodeledSideEffects() ||
SequenceMBBI->mayLoadOrStore() ||
SequenceMBBI->usesCustomInsertionHook())
break;
if (llvm::any_of(SequenceMBBI->operands(), [&](MachineOperand &MO) {
return MO.isReg() && MO.isUse() && SelectDests.count(MO.getReg());
}))
break;
}
const RISCVInstrInfo &TII = *Subtarget.getInstrInfo();
const BasicBlock *LLVM_BB = BB->getBasicBlock();
DebugLoc DL = MI.getDebugLoc();
MachineFunction::iterator I = ++BB->getIterator();
MachineBasicBlock *HeadMBB = BB;
MachineFunction *F = BB->getParent();
MachineBasicBlock *TailMBB = F->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *IfFalseMBB = F->CreateMachineBasicBlock(LLVM_BB);
F->insert(I, IfFalseMBB);
F->insert(I, TailMBB);
// Transfer debug instructions associated with the selects to TailMBB.
for (MachineInstr *DebugInstr : SelectDebugValues) {
TailMBB->push_back(DebugInstr->removeFromParent());
}
// Move all instructions after the sequence to TailMBB.
TailMBB->splice(TailMBB->end(), HeadMBB,
std::next(LastSelectPseudo->getIterator()), HeadMBB->end());
// Update machine-CFG edges by transferring all successors of the current
// block to the new block which will contain the Phi nodes for the selects.
TailMBB->transferSuccessorsAndUpdatePHIs(HeadMBB);
// Set the successors for HeadMBB.
HeadMBB->addSuccessor(IfFalseMBB);
HeadMBB->addSuccessor(TailMBB);
// Insert appropriate branch.
BuildMI(HeadMBB, DL, TII.getBrCond(CC))
.addReg(LHS)
.addReg(RHS)
.addMBB(TailMBB);
// IfFalseMBB just falls through to TailMBB.
IfFalseMBB->addSuccessor(TailMBB);
// Create PHIs for all of the select pseudo-instructions.
auto SelectMBBI = MI.getIterator();
auto SelectEnd = std::next(LastSelectPseudo->getIterator());
auto InsertionPoint = TailMBB->begin();
while (SelectMBBI != SelectEnd) {
auto Next = std::next(SelectMBBI);
if (isSelectPseudo(*SelectMBBI)) {
// %Result = phi [ %TrueValue, HeadMBB ], [ %FalseValue, IfFalseMBB ]
BuildMI(*TailMBB, InsertionPoint, SelectMBBI->getDebugLoc(),
TII.get(RISCV::PHI), SelectMBBI->getOperand(0).getReg())
.addReg(SelectMBBI->getOperand(4).getReg())
.addMBB(HeadMBB)
.addReg(SelectMBBI->getOperand(5).getReg())
.addMBB(IfFalseMBB);
SelectMBBI->eraseFromParent();
}
SelectMBBI = Next;
}
F->getProperties().reset(MachineFunctionProperties::Property::NoPHIs);
return TailMBB;
}
static MachineBasicBlock *
emitVFCVT_RM_MASK(MachineInstr &MI, MachineBasicBlock *BB, unsigned Opcode) {
DebugLoc DL = MI.getDebugLoc();
const TargetInstrInfo &TII = *BB->getParent()->getSubtarget().getInstrInfo();
MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
Register SavedFRM = MRI.createVirtualRegister(&RISCV::GPRRegClass);
// Update FRM and save the old value.
BuildMI(*BB, MI, DL, TII.get(RISCV::SwapFRMImm), SavedFRM)
.addImm(MI.getOperand(4).getImm());
// Emit an VFCVT without the FRM operand.
assert(MI.getNumOperands() == 8);
auto MIB = BuildMI(*BB, MI, DL, TII.get(Opcode))
.add(MI.getOperand(0))
.add(MI.getOperand(1))
.add(MI.getOperand(2))
.add(MI.getOperand(3))
.add(MI.getOperand(5))
.add(MI.getOperand(6))
.add(MI.getOperand(7));
if (MI.getFlag(MachineInstr::MIFlag::NoFPExcept))
MIB->setFlag(MachineInstr::MIFlag::NoFPExcept);
// Restore FRM.
BuildMI(*BB, MI, DL, TII.get(RISCV::WriteFRM))
.addReg(SavedFRM, RegState::Kill);
// Erase the pseudoinstruction.
MI.eraseFromParent();
return BB;
}
static MachineBasicBlock *emitVFROUND_NOEXCEPT_MASK(MachineInstr &MI,
MachineBasicBlock *BB,
unsigned CVTXOpc,
unsigned CVTFOpc) {
DebugLoc DL = MI.getDebugLoc();
const TargetInstrInfo &TII = *BB->getParent()->getSubtarget().getInstrInfo();
MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
Register SavedFFLAGS = MRI.createVirtualRegister(&RISCV::GPRRegClass);
// Save the old value of FFLAGS.
BuildMI(*BB, MI, DL, TII.get(RISCV::ReadFFLAGS), SavedFFLAGS);
assert(MI.getNumOperands() == 7);
// Emit a VFCVT_X_F
const TargetRegisterInfo *TRI =
BB->getParent()->getSubtarget().getRegisterInfo();
const TargetRegisterClass *RC = MI.getRegClassConstraint(0, &TII, TRI);
Register Tmp = MRI.createVirtualRegister(RC);
BuildMI(*BB, MI, DL, TII.get(CVTXOpc), Tmp)
.add(MI.getOperand(1))
.add(MI.getOperand(2))
.add(MI.getOperand(3))
.add(MI.getOperand(4))
.add(MI.getOperand(5))
.add(MI.getOperand(6));
// Emit a VFCVT_F_X
BuildMI(*BB, MI, DL, TII.get(CVTFOpc))
.add(MI.getOperand(0))
.add(MI.getOperand(1))
.addReg(Tmp)
.add(MI.getOperand(3))
.add(MI.getOperand(4))
.add(MI.getOperand(5))
.add(MI.getOperand(6));
// Restore FFLAGS.
BuildMI(*BB, MI, DL, TII.get(RISCV::WriteFFLAGS))
.addReg(SavedFFLAGS, RegState::Kill);
// Erase the pseudoinstruction.
MI.eraseFromParent();
return BB;
}
static MachineBasicBlock *emitFROUND(MachineInstr &MI, MachineBasicBlock *MBB,
const RISCVSubtarget &Subtarget) {
unsigned CmpOpc, F2IOpc, I2FOpc, FSGNJOpc, FSGNJXOpc;
const TargetRegisterClass *RC;
switch (MI.getOpcode()) {
default:
llvm_unreachable("Unexpected opcode");
case RISCV::PseudoFROUND_H:
CmpOpc = RISCV::FLT_H;
F2IOpc = RISCV::FCVT_W_H;
I2FOpc = RISCV::FCVT_H_W;
FSGNJOpc = RISCV::FSGNJ_H;
FSGNJXOpc = RISCV::FSGNJX_H;
RC = &RISCV::FPR16RegClass;
break;
case RISCV::PseudoFROUND_S:
CmpOpc = RISCV::FLT_S;
F2IOpc = RISCV::FCVT_W_S;
I2FOpc = RISCV::FCVT_S_W;
FSGNJOpc = RISCV::FSGNJ_S;
FSGNJXOpc = RISCV::FSGNJX_S;
RC = &RISCV::FPR32RegClass;
break;
case RISCV::PseudoFROUND_D:
assert(Subtarget.is64Bit() && "Expected 64-bit GPR.");
CmpOpc = RISCV::FLT_D;
F2IOpc = RISCV::FCVT_L_D;
I2FOpc = RISCV::FCVT_D_L;
FSGNJOpc = RISCV::FSGNJ_D;
FSGNJXOpc = RISCV::FSGNJX_D;
RC = &RISCV::FPR64RegClass;
break;
}
const BasicBlock *BB = MBB->getBasicBlock();
DebugLoc DL = MI.getDebugLoc();
MachineFunction::iterator I = ++MBB->getIterator();
MachineFunction *F = MBB->getParent();
MachineBasicBlock *CvtMBB = F->CreateMachineBasicBlock(BB);
MachineBasicBlock *DoneMBB = F->CreateMachineBasicBlock(BB);
F->insert(I, CvtMBB);
F->insert(I, DoneMBB);
// Move all instructions after the sequence to DoneMBB.
DoneMBB->splice(DoneMBB->end(), MBB, MachineBasicBlock::iterator(MI),
MBB->end());
// Update machine-CFG edges by transferring all successors of the current
// block to the new block which will contain the Phi nodes for the selects.
DoneMBB->transferSuccessorsAndUpdatePHIs(MBB);
// Set the successors for MBB.
MBB->addSuccessor(CvtMBB);
MBB->addSuccessor(DoneMBB);
Register DstReg = MI.getOperand(0).getReg();
Register SrcReg = MI.getOperand(1).getReg();
Register MaxReg = MI.getOperand(2).getReg();
int64_t FRM = MI.getOperand(3).getImm();
const RISCVInstrInfo &TII = *Subtarget.getInstrInfo();
MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
Register FabsReg = MRI.createVirtualRegister(RC);
BuildMI(MBB, DL, TII.get(FSGNJXOpc), FabsReg).addReg(SrcReg).addReg(SrcReg);
// Compare the FP value to the max value.
Register CmpReg = MRI.createVirtualRegister(&RISCV::GPRRegClass);
auto MIB =
BuildMI(MBB, DL, TII.get(CmpOpc), CmpReg).addReg(FabsReg).addReg(MaxReg);
if (MI.getFlag(MachineInstr::MIFlag::NoFPExcept))
MIB->setFlag(MachineInstr::MIFlag::NoFPExcept);
// Insert branch.
BuildMI(MBB, DL, TII.get(RISCV::BEQ))
.addReg(CmpReg)
.addReg(RISCV::X0)
.addMBB(DoneMBB);
CvtMBB->addSuccessor(DoneMBB);
// Convert to integer.
Register F2IReg = MRI.createVirtualRegister(&RISCV::GPRRegClass);
MIB = BuildMI(CvtMBB, DL, TII.get(F2IOpc), F2IReg).addReg(SrcReg).addImm(FRM);
if (MI.getFlag(MachineInstr::MIFlag::NoFPExcept))
MIB->setFlag(MachineInstr::MIFlag::NoFPExcept);
// Convert back to FP.
Register I2FReg = MRI.createVirtualRegister(RC);
MIB = BuildMI(CvtMBB, DL, TII.get(I2FOpc), I2FReg).addReg(F2IReg).addImm(FRM);
if (MI.getFlag(MachineInstr::MIFlag::NoFPExcept))
MIB->setFlag(MachineInstr::MIFlag::NoFPExcept);
// Restore the sign bit.
Register CvtReg = MRI.createVirtualRegister(RC);
BuildMI(CvtMBB, DL, TII.get(FSGNJOpc), CvtReg).addReg(I2FReg).addReg(SrcReg);
// Merge the results.
BuildMI(*DoneMBB, DoneMBB->begin(), DL, TII.get(RISCV::PHI), DstReg)
.addReg(SrcReg)
.addMBB(MBB)
.addReg(CvtReg)
.addMBB(CvtMBB);
MI.eraseFromParent();
return DoneMBB;
}
MachineBasicBlock *
RISCVTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
MachineBasicBlock *BB) const {
switch (MI.getOpcode()) {
default:
llvm_unreachable("Unexpected instr type to insert");
case RISCV::ReadCycleWide:
assert(!Subtarget.is64Bit() &&
"ReadCycleWrite is only to be used on riscv32");
return emitReadCycleWidePseudo(MI, BB);
case RISCV::Select_GPR_Using_CC_GPR:
case RISCV::Select_FPR16_Using_CC_GPR:
case RISCV::Select_FPR32_Using_CC_GPR:
case RISCV::Select_FPR64_Using_CC_GPR:
return emitSelectPseudo(MI, BB, Subtarget);
case RISCV::BuildPairF64Pseudo:
return emitBuildPairF64Pseudo(MI, BB, Subtarget);
case RISCV::SplitF64Pseudo:
return emitSplitF64Pseudo(MI, BB, Subtarget);
case RISCV::PseudoQuietFLE_H:
return emitQuietFCMP(MI, BB, RISCV::FLE_H, RISCV::FEQ_H, Subtarget);
case RISCV::PseudoQuietFLT_H:
return emitQuietFCMP(MI, BB, RISCV::FLT_H, RISCV::FEQ_H, Subtarget);
case RISCV::PseudoQuietFLE_S:
return emitQuietFCMP(MI, BB, RISCV::FLE_S, RISCV::FEQ_S, Subtarget);
case RISCV::PseudoQuietFLT_S:
return emitQuietFCMP(MI, BB, RISCV::FLT_S, RISCV::FEQ_S, Subtarget);
case RISCV::PseudoQuietFLE_D:
return emitQuietFCMP(MI, BB, RISCV::FLE_D, RISCV::FEQ_D, Subtarget);
case RISCV::PseudoQuietFLT_D:
return emitQuietFCMP(MI, BB, RISCV::FLT_D, RISCV::FEQ_D, Subtarget);
// =========================================================================
// VFCVT
// =========================================================================
case RISCV::PseudoVFCVT_RM_X_F_V_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_M1_MASK);
case RISCV::PseudoVFCVT_RM_X_F_V_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_M2_MASK);
case RISCV::PseudoVFCVT_RM_X_F_V_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_M4_MASK);
case RISCV::PseudoVFCVT_RM_X_F_V_M8_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_M8_MASK);
case RISCV::PseudoVFCVT_RM_X_F_V_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_MF2_MASK);
case RISCV::PseudoVFCVT_RM_X_F_V_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_MF4_MASK);
case RISCV::PseudoVFCVT_RM_XU_F_V_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_XU_F_V_M1_MASK);
case RISCV::PseudoVFCVT_RM_XU_F_V_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_XU_F_V_M2_MASK);
case RISCV::PseudoVFCVT_RM_XU_F_V_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_XU_F_V_M4_MASK);
case RISCV::PseudoVFCVT_RM_XU_F_V_M8_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_XU_F_V_M8_MASK);
case RISCV::PseudoVFCVT_RM_XU_F_V_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_XU_F_V_MF2_MASK);
case RISCV::PseudoVFCVT_RM_XU_F_V_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_XU_F_V_MF4_MASK);
case RISCV::PseudoVFCVT_RM_F_XU_V_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_XU_V_M1_MASK);
case RISCV::PseudoVFCVT_RM_F_XU_V_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_XU_V_M2_MASK);
case RISCV::PseudoVFCVT_RM_F_XU_V_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_XU_V_M4_MASK);
case RISCV::PseudoVFCVT_RM_F_XU_V_M8_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_XU_V_M8_MASK);
case RISCV::PseudoVFCVT_RM_F_XU_V_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_XU_V_MF2_MASK);
case RISCV::PseudoVFCVT_RM_F_XU_V_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_XU_V_MF4_MASK);
case RISCV::PseudoVFCVT_RM_F_X_V_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_X_V_M1_MASK);
case RISCV::PseudoVFCVT_RM_F_X_V_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_X_V_M2_MASK);
case RISCV::PseudoVFCVT_RM_F_X_V_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_X_V_M4_MASK);
case RISCV::PseudoVFCVT_RM_F_X_V_M8_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_X_V_M8_MASK);
case RISCV::PseudoVFCVT_RM_F_X_V_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_X_V_MF2_MASK);
case RISCV::PseudoVFCVT_RM_F_X_V_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFCVT_F_X_V_MF4_MASK);
// =========================================================================
// VFWCVT
// =========================================================================
case RISCV::PseudoVFWCVT_RM_XU_F_V_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_M1_MASK);
case RISCV::PseudoVFWCVT_RM_XU_F_V_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_M2_MASK);
case RISCV::PseudoVFWCVT_RM_XU_F_V_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_M4_MASK);
case RISCV::PseudoVFWCVT_RM_XU_F_V_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_MF2_MASK);
case RISCV::PseudoVFWCVT_RM_XU_F_V_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_MF4_MASK);
case RISCV::PseudoVFWCVT_RM_X_F_V_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_M1_MASK);
case RISCV::PseudoVFWCVT_RM_X_F_V_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_M2_MASK);
case RISCV::PseudoVFWCVT_RM_X_F_V_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_M4_MASK);
case RISCV::PseudoVFWCVT_RM_X_F_V_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_MF2_MASK);
case RISCV::PseudoVFWCVT_RM_X_F_V_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_X_F_V_MF4_MASK);
case RISCV::PseudoVFWCVT_RM_F_XU_V_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_M1_MASK);
case RISCV::PseudoVFWCVT_RM_F_XU_V_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_M2_MASK);
case RISCV::PseudoVFWCVT_RM_F_XU_V_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_M4_MASK);
case RISCV::PseudoVFWCVT_RM_F_XU_V_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_MF2_MASK);
case RISCV::PseudoVFWCVT_RM_F_XU_V_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_MF4_MASK);
case RISCV::PseudoVFWCVT_RM_F_XU_V_MF8_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_MF8_MASK);
case RISCV::PseudoVFWCVT_RM_F_X_V_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_M1_MASK);
case RISCV::PseudoVFWCVT_RM_F_X_V_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_M2_MASK);
case RISCV::PseudoVFWCVT_RM_F_X_V_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_M4_MASK);
case RISCV::PseudoVFWCVT_RM_F_X_V_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_MF2_MASK);
case RISCV::PseudoVFWCVT_RM_F_X_V_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_MF4_MASK);
case RISCV::PseudoVFWCVT_RM_F_X_V_MF8_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFWCVT_F_XU_V_MF8_MASK);
// =========================================================================
// VFNCVT
// =========================================================================
case RISCV::PseudoVFNCVT_RM_XU_F_W_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_M1_MASK);
case RISCV::PseudoVFNCVT_RM_XU_F_W_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_M2_MASK);
case RISCV::PseudoVFNCVT_RM_XU_F_W_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_M4_MASK);
case RISCV::PseudoVFNCVT_RM_XU_F_W_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_MF2_MASK);
case RISCV::PseudoVFNCVT_RM_XU_F_W_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_MF4_MASK);
case RISCV::PseudoVFNCVT_RM_XU_F_W_MF8_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_XU_F_W_MF8_MASK);
case RISCV::PseudoVFNCVT_RM_X_F_W_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_M1_MASK);
case RISCV::PseudoVFNCVT_RM_X_F_W_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_M2_MASK);
case RISCV::PseudoVFNCVT_RM_X_F_W_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_M4_MASK);
case RISCV::PseudoVFNCVT_RM_X_F_W_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_MF2_MASK);
case RISCV::PseudoVFNCVT_RM_X_F_W_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_MF4_MASK);
case RISCV::PseudoVFNCVT_RM_X_F_W_MF8_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_X_F_W_MF8_MASK);
case RISCV::PseudoVFNCVT_RM_F_XU_W_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_M1_MASK);
case RISCV::PseudoVFNCVT_RM_F_XU_W_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_M2_MASK);
case RISCV::PseudoVFNCVT_RM_F_XU_W_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_M4_MASK);
case RISCV::PseudoVFNCVT_RM_F_XU_W_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_MF2_MASK);
case RISCV::PseudoVFNCVT_RM_F_XU_W_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_MF4_MASK);
case RISCV::PseudoVFNCVT_RM_F_X_W_M1_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_M1_MASK);
case RISCV::PseudoVFNCVT_RM_F_X_W_M2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_M2_MASK);
case RISCV::PseudoVFNCVT_RM_F_X_W_M4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_M4_MASK);
case RISCV::PseudoVFNCVT_RM_F_X_W_MF2_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_MF2_MASK);
case RISCV::PseudoVFNCVT_RM_F_X_W_MF4_MASK:
return emitVFCVT_RM_MASK(MI, BB, RISCV::PseudoVFNCVT_F_XU_W_MF4_MASK);
case RISCV::PseudoVFROUND_NOEXCEPT_V_M1_MASK:
return emitVFROUND_NOEXCEPT_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_M1_MASK,
RISCV::PseudoVFCVT_F_X_V_M1_MASK);
case RISCV::PseudoVFROUND_NOEXCEPT_V_M2_MASK:
return emitVFROUND_NOEXCEPT_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_M2_MASK,
RISCV::PseudoVFCVT_F_X_V_M2_MASK);
case RISCV::PseudoVFROUND_NOEXCEPT_V_M4_MASK:
return emitVFROUND_NOEXCEPT_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_M4_MASK,
RISCV::PseudoVFCVT_F_X_V_M4_MASK);
case RISCV::PseudoVFROUND_NOEXCEPT_V_M8_MASK:
return emitVFROUND_NOEXCEPT_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_M8_MASK,
RISCV::PseudoVFCVT_F_X_V_M8_MASK);
case RISCV::PseudoVFROUND_NOEXCEPT_V_MF2_MASK:
return emitVFROUND_NOEXCEPT_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_MF2_MASK,
RISCV::PseudoVFCVT_F_X_V_MF2_MASK);
case RISCV::PseudoVFROUND_NOEXCEPT_V_MF4_MASK:
return emitVFROUND_NOEXCEPT_MASK(MI, BB, RISCV::PseudoVFCVT_X_F_V_MF4_MASK,
RISCV::PseudoVFCVT_F_X_V_MF4_MASK);
case RISCV::PseudoFROUND_H:
case RISCV::PseudoFROUND_S:
case RISCV::PseudoFROUND_D:
return emitFROUND(MI, BB, Subtarget);
}
}
void RISCVTargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
SDNode *Node) const {
// Add FRM dependency to any instructions with dynamic rounding mode.
unsigned Opc = MI.getOpcode();
auto Idx = RISCV::getNamedOperandIdx(Opc, RISCV::OpName::frm);
if (Idx < 0)
return;
if (MI.getOperand(Idx).getImm() != RISCVFPRndMode::DYN)
return;
// If the instruction already reads FRM, don't add another read.
if (MI.readsRegister(RISCV::FRM))
return;
MI.addOperand(
MachineOperand::CreateReg(RISCV::FRM, /*isDef*/ false, /*isImp*/ true));
}
// Calling Convention Implementation.
// The expectations for frontend ABI lowering vary from target to target.
// Ideally, an LLVM frontend would be able to avoid worrying about many ABI
// details, but this is a longer term goal. For now, we simply try to keep the
// role of the frontend as simple and well-defined as possible. The rules can
// be summarised as:
// * Never split up large scalar arguments. We handle them here.
// * If a hardfloat calling convention is being used, and the struct may be
// passed in a pair of registers (fp+fp, int+fp), and both registers are
// available, then pass as two separate arguments. If either the GPRs or FPRs
// are exhausted, then pass according to the rule below.
// * If a struct could never be passed in registers or directly in a stack
// slot (as it is larger than 2*XLEN and the floating point rules don't
// apply), then pass it using a pointer with the byval attribute.
// * If a struct is less than 2*XLEN, then coerce to either a two-element
// word-sized array or a 2*XLEN scalar (depending on alignment).
// * The frontend can determine whether a struct is returned by reference or
// not based on its size and fields. If it will be returned by reference, the
// frontend must modify the prototype so a pointer with the sret annotation is
// passed as the first argument. This is not necessary for large scalar
// returns.
// * Struct return values and varargs should be coerced to structs containing
// register-size fields in the same situations they would be for fixed
// arguments.
static const MCPhysReg ArgGPRs[] = {
RISCV::X10, RISCV::X11, RISCV::X12, RISCV::X13,
RISCV::X14, RISCV::X15, RISCV::X16, RISCV::X17
};
static const MCPhysReg ArgFPR16s[] = {
RISCV::F10_H, RISCV::F11_H, RISCV::F12_H, RISCV::F13_H,
RISCV::F14_H, RISCV::F15_H, RISCV::F16_H, RISCV::F17_H
};
static const MCPhysReg ArgFPR32s[] = {
RISCV::F10_F, RISCV::F11_F, RISCV::F12_F, RISCV::F13_F,
RISCV::F14_F, RISCV::F15_F, RISCV::F16_F, RISCV::F17_F
};
static const MCPhysReg ArgFPR64s[] = {
RISCV::F10_D, RISCV::F11_D, RISCV::F12_D, RISCV::F13_D,
RISCV::F14_D, RISCV::F15_D, RISCV::F16_D, RISCV::F17_D
};
// This is an interim calling convention and it may be changed in the future.
static const MCPhysReg ArgVRs[] = {
RISCV::V8, RISCV::V9, RISCV::V10, RISCV::V11, RISCV::V12, RISCV::V13,
RISCV::V14, RISCV::V15, RISCV::V16, RISCV::V17, RISCV::V18, RISCV::V19,
RISCV::V20, RISCV::V21, RISCV::V22, RISCV::V23};
static const MCPhysReg ArgVRM2s[] = {RISCV::V8M2, RISCV::V10M2, RISCV::V12M2,
RISCV::V14M2, RISCV::V16M2, RISCV::V18M2,
RISCV::V20M2, RISCV::V22M2};
static const MCPhysReg ArgVRM4s[] = {RISCV::V8M4, RISCV::V12M4, RISCV::V16M4,
RISCV::V20M4};
static const MCPhysReg ArgVRM8s[] = {RISCV::V8M8, RISCV::V16M8};
// Pass a 2*XLEN argument that has been split into two XLEN values through
// registers or the stack as necessary.
static bool CC_RISCVAssign2XLen(unsigned XLen, CCState &State, CCValAssign VA1,
ISD::ArgFlagsTy ArgFlags1, unsigned ValNo2,
MVT ValVT2, MVT LocVT2,
ISD::ArgFlagsTy ArgFlags2) {
unsigned XLenInBytes = XLen / 8;
if (Register Reg = State.AllocateReg(ArgGPRs)) {
// At least one half can be passed via register.
State.addLoc(CCValAssign::getReg(VA1.getValNo(), VA1.getValVT(), Reg,
VA1.getLocVT(), CCValAssign::Full));
} else {
// Both halves must be passed on the stack, with proper alignment.
Align StackAlign =
std::max(Align(XLenInBytes), ArgFlags1.getNonZeroOrigAlign());
State.addLoc(
CCValAssign::getMem(VA1.getValNo(), VA1.getValVT(),
State.AllocateStack(XLenInBytes, StackAlign),
VA1.getLocVT(), CCValAssign::Full));
State.addLoc(CCValAssign::getMem(
ValNo2, ValVT2, State.AllocateStack(XLenInBytes, Align(XLenInBytes)),
LocVT2, CCValAssign::Full));
return false;
}
if (Register Reg = State.AllocateReg(ArgGPRs)) {
// The second half can also be passed via register.
State.addLoc(
CCValAssign::getReg(ValNo2, ValVT2, Reg, LocVT2, CCValAssign::Full));
} else {
// The second half is passed via the stack, without additional alignment.
State.addLoc(CCValAssign::getMem(
ValNo2, ValVT2, State.AllocateStack(XLenInBytes, Align(XLenInBytes)),
LocVT2, CCValAssign::Full));
}
return false;
}
static unsigned allocateRVVReg(MVT ValVT, unsigned ValNo,
std::optional<unsigned> FirstMaskArgument,
CCState &State, const RISCVTargetLowering &TLI) {
const TargetRegisterClass *RC = TLI.getRegClassFor(ValVT);
if (RC == &RISCV::VRRegClass) {
// Assign the first mask argument to V0.
// This is an interim calling convention and it may be changed in the
// future.
if (FirstMaskArgument && ValNo == *FirstMaskArgument)
return State.AllocateReg(RISCV::V0);
return State.AllocateReg(ArgVRs);
}
if (RC == &RISCV::VRM2RegClass)
return State.AllocateReg(ArgVRM2s);
if (RC == &RISCV::VRM4RegClass)
return State.AllocateReg(ArgVRM4s);
if (RC == &RISCV::VRM8RegClass)
return State.AllocateReg(ArgVRM8s);
llvm_unreachable("Unhandled register class for ValueType");
}
// Implements the RISC-V calling convention. Returns true upon failure.
static bool CC_RISCV(const DataLayout &DL, RISCVABI::ABI ABI, unsigned ValNo,
MVT ValVT, MVT LocVT, CCValAssign::LocInfo LocInfo,
ISD::ArgFlagsTy ArgFlags, CCState &State, bool IsFixed,
bool IsRet, Type *OrigTy, const RISCVTargetLowering &TLI,
std::optional<unsigned> FirstMaskArgument) {
unsigned XLen = DL.getLargestLegalIntTypeSizeInBits();
assert(XLen == 32 || XLen == 64);
MVT XLenVT = XLen == 32 ? MVT::i32 : MVT::i64;
// Static chain parameter must not be passed in normal argument registers,
// so we assign t2 for it as done in GCC's __builtin_call_with_static_chain
if (ArgFlags.isNest()) {
if (unsigned Reg = State.AllocateReg(RISCV::X7)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
}
// Any return value split in to more than two values can't be returned
// directly. Vectors are returned via the available vector registers.
if (!LocVT.isVector() && IsRet && ValNo > 1)
return true;
// UseGPRForF16_F32 if targeting one of the soft-float ABIs, if passing a
// variadic argument, or if no F16/F32 argument registers are available.
bool UseGPRForF16_F32 = true;
// UseGPRForF64 if targeting soft-float ABIs or an FLEN=32 ABI, if passing a
// variadic argument, or if no F64 argument registers are available.
bool UseGPRForF64 = true;
switch (ABI) {
default:
llvm_unreachable("Unexpected ABI");
case RISCVABI::ABI_ILP32:
case RISCVABI::ABI_LP64:
break;
case RISCVABI::ABI_ILP32F:
case RISCVABI::ABI_LP64F:
UseGPRForF16_F32 = !IsFixed;
break;
case RISCVABI::ABI_ILP32D:
case RISCVABI::ABI_LP64D:
UseGPRForF16_F32 = !IsFixed;
UseGPRForF64 = !IsFixed;
break;
}
// FPR16, FPR32, and FPR64 alias each other.
if (State.getFirstUnallocated(ArgFPR32s) == std::size(ArgFPR32s)) {
UseGPRForF16_F32 = true;
UseGPRForF64 = true;
}
// From this point on, rely on UseGPRForF16_F32, UseGPRForF64 and
// similar local variables rather than directly checking against the target
// ABI.
if (UseGPRForF16_F32 && (ValVT == MVT::f16 || ValVT == MVT::f32)) {
LocVT = XLenVT;
LocInfo = CCValAssign::BCvt;
} else if (UseGPRForF64 && XLen == 64 && ValVT == MVT::f64) {
LocVT = MVT::i64;
LocInfo = CCValAssign::BCvt;
}
// If this is a variadic argument, the RISC-V calling convention requires
// that it is assigned an 'even' or 'aligned' register if it has 8-byte
// alignment (RV32) or 16-byte alignment (RV64). An aligned register should
// be used regardless of whether the original argument was split during
// legalisation or not. The argument will not be passed by registers if the
// original type is larger than 2*XLEN, so the register alignment rule does
// not apply.
unsigned TwoXLenInBytes = (2 * XLen) / 8;
if (!IsFixed && ArgFlags.getNonZeroOrigAlign() == TwoXLenInBytes &&
DL.getTypeAllocSize(OrigTy) == TwoXLenInBytes) {
unsigned RegIdx = State.getFirstUnallocated(ArgGPRs);
// Skip 'odd' register if necessary.
if (RegIdx != std::size(ArgGPRs) && RegIdx % 2 == 1)
State.AllocateReg(ArgGPRs);
}
SmallVectorImpl<CCValAssign> &PendingLocs = State.getPendingLocs();
SmallVectorImpl<ISD::ArgFlagsTy> &PendingArgFlags =
State.getPendingArgFlags();
assert(PendingLocs.size() == PendingArgFlags.size() &&
"PendingLocs and PendingArgFlags out of sync");
// Handle passing f64 on RV32D with a soft float ABI or when floating point
// registers are exhausted.
if (UseGPRForF64 && XLen == 32 && ValVT == MVT::f64) {
assert(!ArgFlags.isSplit() && PendingLocs.empty() &&
"Can't lower f64 if it is split");
// Depending on available argument GPRS, f64 may be passed in a pair of
// GPRs, split between a GPR and the stack, or passed completely on the
// stack. LowerCall/LowerFormalArguments/LowerReturn must recognise these
// cases.
Register Reg = State.AllocateReg(ArgGPRs);
LocVT = MVT::i32;
if (!Reg) {
unsigned StackOffset = State.AllocateStack(8, Align(8));
State.addLoc(
CCValAssign::getMem(ValNo, ValVT, StackOffset, LocVT, LocInfo));
return false;
}
if (!State.AllocateReg(ArgGPRs))
State.AllocateStack(4, Align(4));
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
// Fixed-length vectors are located in the corresponding scalable-vector
// container types.
if (ValVT.isFixedLengthVector())
LocVT = TLI.getContainerForFixedLengthVector(LocVT);
// Split arguments might be passed indirectly, so keep track of the pending
// values. Split vectors are passed via a mix of registers and indirectly, so
// treat them as we would any other argument.
if (ValVT.isScalarInteger() && (ArgFlags.isSplit() || !PendingLocs.empty())) {
LocVT = XLenVT;
LocInfo = CCValAssign::Indirect;
PendingLocs.push_back(
CCValAssign::getPending(ValNo, ValVT, LocVT, LocInfo));
PendingArgFlags.push_back(ArgFlags);
if (!ArgFlags.isSplitEnd()) {
return false;
}
}
// If the split argument only had two elements, it should be passed directly
// in registers or on the stack.
if (ValVT.isScalarInteger() && ArgFlags.isSplitEnd() &&
PendingLocs.size() <= 2) {
assert(PendingLocs.size() == 2 && "Unexpected PendingLocs.size()");
// Apply the normal calling convention rules to the first half of the
// split argument.
CCValAssign VA = PendingLocs[0];
ISD::ArgFlagsTy AF = PendingArgFlags[0];
PendingLocs.clear();
PendingArgFlags.clear();
return CC_RISCVAssign2XLen(XLen, State, VA, AF, ValNo, ValVT, LocVT,
ArgFlags);
}
// Allocate to a register if possible, or else a stack slot.
Register Reg;
unsigned StoreSizeBytes = XLen / 8;
Align StackAlign = Align(XLen / 8);
if (ValVT == MVT::f16 && !UseGPRForF16_F32)
Reg = State.AllocateReg(ArgFPR16s);
else if (ValVT == MVT::f32 && !UseGPRForF16_F32)
Reg = State.AllocateReg(ArgFPR32s);
else if (ValVT == MVT::f64 && !UseGPRForF64)
Reg = State.AllocateReg(ArgFPR64s);
else if (ValVT.isVector()) {
Reg = allocateRVVReg(ValVT, ValNo, FirstMaskArgument, State, TLI);
if (!Reg) {
// For return values, the vector must be passed fully via registers or
// via the stack.
// FIXME: The proposed vector ABI only mandates v8-v15 for return values,
// but we're using all of them.
if (IsRet)
return true;
// Try using a GPR to pass the address
if ((Reg = State.AllocateReg(ArgGPRs))) {
LocVT = XLenVT;
LocInfo = CCValAssign::Indirect;
} else if (ValVT.isScalableVector()) {
LocVT = XLenVT;
LocInfo = CCValAssign::Indirect;
} else {
// Pass fixed-length vectors on the stack.
LocVT = ValVT;
StoreSizeBytes = ValVT.getStoreSize();
// Align vectors to their element sizes, being careful for vXi1
// vectors.
StackAlign = MaybeAlign(ValVT.getScalarSizeInBits() / 8).valueOrOne();
}
}
} else {
Reg = State.AllocateReg(ArgGPRs);
}
unsigned StackOffset =
Reg ? 0 : State.AllocateStack(StoreSizeBytes, StackAlign);
// If we reach this point and PendingLocs is non-empty, we must be at the
// end of a split argument that must be passed indirectly.
if (!PendingLocs.empty()) {
assert(ArgFlags.isSplitEnd() && "Expected ArgFlags.isSplitEnd()");
assert(PendingLocs.size() > 2 && "Unexpected PendingLocs.size()");
for (auto &It : PendingLocs) {
if (Reg)
It.convertToReg(Reg);
else
It.convertToMem(StackOffset);
State.addLoc(It);
}
PendingLocs.clear();
PendingArgFlags.clear();
return false;
}
assert((!UseGPRForF16_F32 || !UseGPRForF64 || LocVT == XLenVT ||
(TLI.getSubtarget().hasVInstructions() && ValVT.isVector())) &&
"Expected an XLenVT or vector types at this stage");
if (Reg) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
// When a scalar floating-point value is passed on the stack, no
// bit-conversion is needed.
if (ValVT.isFloatingPoint() && LocInfo != CCValAssign::Indirect) {
assert(!ValVT.isVector());
LocVT = ValVT;
LocInfo = CCValAssign::Full;
}
State.addLoc(CCValAssign::getMem(ValNo, ValVT, StackOffset, LocVT, LocInfo));
return false;
}
template <typename ArgTy>
static std::optional<unsigned> preAssignMask(const ArgTy &Args) {
for (const auto &ArgIdx : enumerate(Args)) {
MVT ArgVT = ArgIdx.value().VT;
if (ArgVT.isVector() && ArgVT.getVectorElementType() == MVT::i1)
return ArgIdx.index();
}
return std::nullopt;
}
void RISCVTargetLowering::analyzeInputArgs(
MachineFunction &MF, CCState &CCInfo,
const SmallVectorImpl<ISD::InputArg> &Ins, bool IsRet,
RISCVCCAssignFn Fn) const {
unsigned NumArgs = Ins.size();
FunctionType *FType = MF.getFunction().getFunctionType();
std::optional<unsigned> FirstMaskArgument;
if (Subtarget.hasVInstructions())
FirstMaskArgument = preAssignMask(Ins);
for (unsigned i = 0; i != NumArgs; ++i) {
MVT ArgVT = Ins[i].VT;
ISD::ArgFlagsTy ArgFlags = Ins[i].Flags;
Type *ArgTy = nullptr;
if (IsRet)
ArgTy = FType->getReturnType();
else if (Ins[i].isOrigArg())
ArgTy = FType->getParamType(Ins[i].getOrigArgIndex());
RISCVABI::ABI ABI = MF.getSubtarget<RISCVSubtarget>().getTargetABI();
if (Fn(MF.getDataLayout(), ABI, i, ArgVT, ArgVT, CCValAssign::Full,
ArgFlags, CCInfo, /*IsFixed=*/true, IsRet, ArgTy, *this,
FirstMaskArgument)) {
LLVM_DEBUG(dbgs() << "InputArg #" << i << " has unhandled type "
<< ArgVT << '\n');
llvm_unreachable(nullptr);
}
}
}
void RISCVTargetLowering::analyzeOutputArgs(
MachineFunction &MF, CCState &CCInfo,
const SmallVectorImpl<ISD::OutputArg> &Outs, bool IsRet,
CallLoweringInfo *CLI, RISCVCCAssignFn Fn) const {
unsigned NumArgs = Outs.size();
std::optional<unsigned> FirstMaskArgument;
if (Subtarget.hasVInstructions())
FirstMaskArgument = preAssignMask(Outs);
for (unsigned i = 0; i != NumArgs; i++) {
MVT ArgVT = Outs[i].VT;
ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
Type *OrigTy = CLI ? CLI->getArgs()[Outs[i].OrigArgIndex].Ty : nullptr;
RISCVABI::ABI ABI = MF.getSubtarget<RISCVSubtarget>().getTargetABI();
if (Fn(MF.getDataLayout(), ABI, i, ArgVT, ArgVT, CCValAssign::Full,
ArgFlags, CCInfo, Outs[i].IsFixed, IsRet, OrigTy, *this,
FirstMaskArgument)) {
LLVM_DEBUG(dbgs() << "OutputArg #" << i << " has unhandled type "
<< ArgVT << "\n");
llvm_unreachable(nullptr);
}
}
}
// Convert Val to a ValVT. Should not be called for CCValAssign::Indirect
// values.
static SDValue convertLocVTToValVT(SelectionDAG &DAG, SDValue Val,
const CCValAssign &VA, const SDLoc &DL,
const RISCVSubtarget &Subtarget) {
switch (VA.getLocInfo()) {
default:
llvm_unreachable("Unexpected CCValAssign::LocInfo");
case CCValAssign::Full:
if (VA.getValVT().isFixedLengthVector() && VA.getLocVT().isScalableVector())
Val = convertFromScalableVector(VA.getValVT(), Val, DAG, Subtarget);
break;
case CCValAssign::BCvt:
if (VA.getLocVT().isInteger() && VA.getValVT() == MVT::f16)
Val = DAG.getNode(RISCVISD::FMV_H_X, DL, MVT::f16, Val);
else if (VA.getLocVT() == MVT::i64 && VA.getValVT() == MVT::f32)
Val = DAG.getNode(RISCVISD::FMV_W_X_RV64, DL, MVT::f32, Val);
else
Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
break;
}
return Val;
}
// The caller is responsible for loading the full value if the argument is
// passed with CCValAssign::Indirect.
static SDValue unpackFromRegLoc(SelectionDAG &DAG, SDValue Chain,
const CCValAssign &VA, const SDLoc &DL,
const ISD::InputArg &In,
const RISCVTargetLowering &TLI) {
MachineFunction &MF = DAG.getMachineFunction();
MachineRegisterInfo &RegInfo = MF.getRegInfo();
EVT LocVT = VA.getLocVT();
SDValue Val;
const TargetRegisterClass *RC = TLI.getRegClassFor(LocVT.getSimpleVT());
Register VReg = RegInfo.createVirtualRegister(RC);
RegInfo.addLiveIn(VA.getLocReg(), VReg);
Val = DAG.getCopyFromReg(Chain, DL, VReg, LocVT);
// If input is sign extended from 32 bits, note it for the SExtWRemoval pass.
if (In.isOrigArg()) {
Argument *OrigArg = MF.getFunction().getArg(In.getOrigArgIndex());
if (OrigArg->getType()->isIntegerTy()) {
unsigned BitWidth = OrigArg->getType()->getIntegerBitWidth();
// An input zero extended from i31 can also be considered sign extended.
if ((BitWidth <= 32 && In.Flags.isSExt()) ||
(BitWidth < 32 && In.Flags.isZExt())) {
RISCVMachineFunctionInfo *RVFI = MF.getInfo<RISCVMachineFunctionInfo>();
RVFI->addSExt32Register(VReg);
}
}
}
if (VA.getLocInfo() == CCValAssign::Indirect)
return Val;
return convertLocVTToValVT(DAG, Val, VA, DL, TLI.getSubtarget());
}
static SDValue convertValVTToLocVT(SelectionDAG &DAG, SDValue Val,
const CCValAssign &VA, const SDLoc &DL,
const RISCVSubtarget &Subtarget) {
EVT LocVT = VA.getLocVT();
switch (VA.getLocInfo()) {
default:
llvm_unreachable("Unexpected CCValAssign::LocInfo");
case CCValAssign::Full:
if (VA.getValVT().isFixedLengthVector() && LocVT.isScalableVector())
Val = convertToScalableVector(LocVT, Val, DAG, Subtarget);
break;
case CCValAssign::BCvt:
if (VA.getLocVT().isInteger() && VA.getValVT() == MVT::f16)
Val = DAG.getNode(RISCVISD::FMV_X_ANYEXTH, DL, VA.getLocVT(), Val);
else if (VA.getLocVT() == MVT::i64 && VA.getValVT() == MVT::f32)
Val = DAG.getNode(RISCVISD::FMV_X_ANYEXTW_RV64, DL, MVT::i64, Val);
else
Val = DAG.getNode(ISD::BITCAST, DL, LocVT, Val);
break;
}
return Val;
}
// The caller is responsible for loading the full value if the argument is
// passed with CCValAssign::Indirect.
static SDValue unpackFromMemLoc(SelectionDAG &DAG, SDValue Chain,
const CCValAssign &VA, const SDLoc &DL) {
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo &MFI = MF.getFrameInfo();
EVT LocVT = VA.getLocVT();
EVT ValVT = VA.getValVT();
EVT PtrVT = MVT::getIntegerVT(DAG.getDataLayout().getPointerSizeInBits(0));
if (ValVT.isScalableVector()) {
// When the value is a scalable vector, we save the pointer which points to
// the scalable vector value in the stack. The ValVT will be the pointer
// type, instead of the scalable vector type.
ValVT = LocVT;
}
int FI = MFI.CreateFixedObject(ValVT.getStoreSize(), VA.getLocMemOffset(),
/*IsImmutable=*/true);
SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
SDValue Val;
ISD::LoadExtType ExtType;
switch (VA.getLocInfo()) {
default:
llvm_unreachable("Unexpected CCValAssign::LocInfo");
case CCValAssign::Full:
case CCValAssign::Indirect:
case CCValAssign::BCvt:
ExtType = ISD::NON_EXTLOAD;
break;
}
Val = DAG.getExtLoad(
ExtType, DL, LocVT, Chain, FIN,
MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI), ValVT);
return Val;
}
static SDValue unpackF64OnRV32DSoftABI(SelectionDAG &DAG, SDValue Chain,
const CCValAssign &VA, const SDLoc &DL) {
assert(VA.getLocVT() == MVT::i32 && VA.getValVT() == MVT::f64 &&
"Unexpected VA");
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo &MFI = MF.getFrameInfo();
MachineRegisterInfo &RegInfo = MF.getRegInfo();
if (VA.isMemLoc()) {
// f64 is passed on the stack.
int FI =
MFI.CreateFixedObject(8, VA.getLocMemOffset(), /*IsImmutable=*/true);
SDValue FIN = DAG.getFrameIndex(FI, MVT::i32);
return DAG.getLoad(MVT::f64, DL, Chain, FIN,
MachinePointerInfo::getFixedStack(MF, FI));
}
assert(VA.isRegLoc() && "Expected register VA assignment");
Register LoVReg = RegInfo.createVirtualRegister(&RISCV::GPRRegClass);
RegInfo.addLiveIn(VA.getLocReg(), LoVReg);
SDValue Lo = DAG.getCopyFromReg(Chain, DL, LoVReg, MVT::i32);
SDValue Hi;
if (VA.getLocReg() == RISCV::X17) {
// Second half of f64 is passed on the stack.
int FI = MFI.CreateFixedObject(4, 0, /*IsImmutable=*/true);
SDValue FIN = DAG.getFrameIndex(FI, MVT::i32);
Hi = DAG.getLoad(MVT::i32, DL, Chain, FIN,
MachinePointerInfo::getFixedStack(MF, FI));
} else {
// Second half of f64 is passed in another GPR.
Register HiVReg = RegInfo.createVirtualRegister(&RISCV::GPRRegClass);
RegInfo.addLiveIn(VA.getLocReg() + 1, HiVReg);
Hi = DAG.getCopyFromReg(Chain, DL, HiVReg, MVT::i32);
}
return DAG.getNode(RISCVISD::BuildPairF64, DL, MVT::f64, Lo, Hi);
}
// FastCC has less than 1% performance improvement for some particular
// benchmark. But theoretically, it may has benenfit for some cases.
static bool CC_RISCV_FastCC(const DataLayout &DL, RISCVABI::ABI ABI,
unsigned ValNo, MVT ValVT, MVT LocVT,
CCValAssign::LocInfo LocInfo,
ISD::ArgFlagsTy ArgFlags, CCState &State,
bool IsFixed, bool IsRet, Type *OrigTy,
const RISCVTargetLowering &TLI,
std::optional<unsigned> FirstMaskArgument) {
// X5 and X6 might be used for save-restore libcall.
static const MCPhysReg GPRList[] = {
RISCV::X10, RISCV::X11, RISCV::X12, RISCV::X13, RISCV::X14,
RISCV::X15, RISCV::X16, RISCV::X17, RISCV::X7, RISCV::X28,
RISCV::X29, RISCV::X30, RISCV::X31};
if (LocVT == MVT::i32 || LocVT == MVT::i64) {
if (unsigned Reg = State.AllocateReg(GPRList)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
}
if (LocVT == MVT::f16) {
static const MCPhysReg FPR16List[] = {
RISCV::F10_H, RISCV::F11_H, RISCV::F12_H, RISCV::F13_H, RISCV::F14_H,
RISCV::F15_H, RISCV::F16_H, RISCV::F17_H, RISCV::F0_H, RISCV::F1_H,
RISCV::F2_H, RISCV::F3_H, RISCV::F4_H, RISCV::F5_H, RISCV::F6_H,
RISCV::F7_H, RISCV::F28_H, RISCV::F29_H, RISCV::F30_H, RISCV::F31_H};
if (unsigned Reg = State.AllocateReg(FPR16List)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
}
if (LocVT == MVT::f32) {
static const MCPhysReg FPR32List[] = {
RISCV::F10_F, RISCV::F11_F, RISCV::F12_F, RISCV::F13_F, RISCV::F14_F,
RISCV::F15_F, RISCV::F16_F, RISCV::F17_F, RISCV::F0_F, RISCV::F1_F,
RISCV::F2_F, RISCV::F3_F, RISCV::F4_F, RISCV::F5_F, RISCV::F6_F,
RISCV::F7_F, RISCV::F28_F, RISCV::F29_F, RISCV::F30_F, RISCV::F31_F};
if (unsigned Reg = State.AllocateReg(FPR32List)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
}
if (LocVT == MVT::f64) {
static const MCPhysReg FPR64List[] = {
RISCV::F10_D, RISCV::F11_D, RISCV::F12_D, RISCV::F13_D, RISCV::F14_D,
RISCV::F15_D, RISCV::F16_D, RISCV::F17_D, RISCV::F0_D, RISCV::F1_D,
RISCV::F2_D, RISCV::F3_D, RISCV::F4_D, RISCV::F5_D, RISCV::F6_D,
RISCV::F7_D, RISCV::F28_D, RISCV::F29_D, RISCV::F30_D, RISCV::F31_D};
if (unsigned Reg = State.AllocateReg(FPR64List)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
}
if (LocVT == MVT::i32 || LocVT == MVT::f32) {
unsigned Offset4 = State.AllocateStack(4, Align(4));
State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset4, LocVT, LocInfo));
return false;
}
if (LocVT == MVT::i64 || LocVT == MVT::f64) {
unsigned Offset5 = State.AllocateStack(8, Align(8));
State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset5, LocVT, LocInfo));
return false;
}
if (LocVT.isVector()) {
if (unsigned Reg =
allocateRVVReg(ValVT, ValNo, FirstMaskArgument, State, TLI)) {
// Fixed-length vectors are located in the corresponding scalable-vector
// container types.
if (ValVT.isFixedLengthVector())
LocVT = TLI.getContainerForFixedLengthVector(LocVT);
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
} else {
// Try and pass the address via a "fast" GPR.
if (unsigned GPRReg = State.AllocateReg(GPRList)) {
LocInfo = CCValAssign::Indirect;
LocVT = TLI.getSubtarget().getXLenVT();
State.addLoc(CCValAssign::getReg(ValNo, ValVT, GPRReg, LocVT, LocInfo));
} else if (ValVT.isFixedLengthVector()) {
auto StackAlign =
MaybeAlign(ValVT.getScalarSizeInBits() / 8).valueOrOne();
unsigned StackOffset =
State.AllocateStack(ValVT.getStoreSize(), StackAlign);
State.addLoc(
CCValAssign::getMem(ValNo, ValVT, StackOffset, LocVT, LocInfo));
} else {
// Can't pass scalable vectors on the stack.
return true;
}
}
return false;
}
return true; // CC didn't match.
}
static bool CC_RISCV_GHC(unsigned ValNo, MVT ValVT, MVT LocVT,
CCValAssign::LocInfo LocInfo,
ISD::ArgFlagsTy ArgFlags, CCState &State) {
if (ArgFlags.isNest()) {
report_fatal_error(
"Attribute 'nest' is not supported in GHC calling convention");
}
if (LocVT == MVT::i32 || LocVT == MVT::i64) {
// Pass in STG registers: Base, Sp, Hp, R1, R2, R3, R4, R5, R6, R7, SpLim
// s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
static const MCPhysReg GPRList[] = {
RISCV::X9, RISCV::X18, RISCV::X19, RISCV::X20, RISCV::X21, RISCV::X22,
RISCV::X23, RISCV::X24, RISCV::X25, RISCV::X26, RISCV::X27};
if (unsigned Reg = State.AllocateReg(GPRList)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
}
if (LocVT == MVT::f32) {
// Pass in STG registers: F1, ..., F6
// fs0 ... fs5
static const MCPhysReg FPR32List[] = {RISCV::F8_F, RISCV::F9_F,
RISCV::F18_F, RISCV::F19_F,
RISCV::F20_F, RISCV::F21_F};
if (unsigned Reg = State.AllocateReg(FPR32List)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
}
if (LocVT == MVT::f64) {
// Pass in STG registers: D1, ..., D6
// fs6 ... fs11
static const MCPhysReg FPR64List[] = {RISCV::F22_D, RISCV::F23_D,
RISCV::F24_D, RISCV::F25_D,
RISCV::F26_D, RISCV::F27_D};
if (unsigned Reg = State.AllocateReg(FPR64List)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false;
}
}
report_fatal_error("No registers left in GHC calling convention");
return true;
}
// Transform physical registers into virtual registers.
SDValue RISCVTargetLowering::LowerFormalArguments(
SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
MachineFunction &MF = DAG.getMachineFunction();
switch (CallConv) {
default:
report_fatal_error("Unsupported calling convention");
case CallingConv::C:
case CallingConv::Fast:
break;
case CallingConv::GHC:
if (!Subtarget.hasStdExtF() || !Subtarget.hasStdExtD())
report_fatal_error(
"GHC calling convention requires the F and D instruction set extensions");
}
const Function &Func = MF.getFunction();
if (Func.hasFnAttribute("interrupt")) {
if (!Func.arg_empty())
report_fatal_error(
"Functions with the interrupt attribute cannot have arguments!");
StringRef Kind =
MF.getFunction().getFnAttribute("interrupt").getValueAsString();
if (!(Kind == "user" || Kind == "supervisor" || Kind == "machine"))
report_fatal_error(
"Function interrupt attribute argument not supported!");
}
EVT PtrVT = getPointerTy(DAG.getDataLayout());
MVT XLenVT = Subtarget.getXLenVT();
unsigned XLenInBytes = Subtarget.getXLen() / 8;
// Used with vargs to acumulate store chains.
std::vector<SDValue> OutChains;
// Assign locations to all of the incoming arguments.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, IsVarArg, MF, ArgLocs, *DAG.getContext());
if (CallConv == CallingConv::GHC)
CCInfo.AnalyzeFormalArguments(Ins, CC_RISCV_GHC);
else
analyzeInputArgs(MF, CCInfo, Ins, /*IsRet=*/false,
CallConv == CallingConv::Fast ? CC_RISCV_FastCC
: CC_RISCV);
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
SDValue ArgValue;
// Passing f64 on RV32D with a soft float ABI must be handled as a special
// case.
if (VA.getLocVT() == MVT::i32 && VA.getValVT() == MVT::f64)
ArgValue = unpackF64OnRV32DSoftABI(DAG, Chain, VA, DL);
else if (VA.isRegLoc())
ArgValue = unpackFromRegLoc(DAG, Chain, VA, DL, Ins[i], *this);
else
ArgValue = unpackFromMemLoc(DAG, Chain, VA, DL);
if (VA.getLocInfo() == CCValAssign::Indirect) {
// If the original argument was split and passed by reference (e.g. i128
// on RV32), we need to load all parts of it here (using the same
// address). Vectors may be partly split to registers and partly to the
// stack, in which case the base address is partly offset and subsequent
// stores are relative to that.
InVals.push_back(DAG.getLoad(VA.getValVT(), DL, Chain, ArgValue,
MachinePointerInfo()));
unsigned ArgIndex = Ins[i].OrigArgIndex;
unsigned ArgPartOffset = Ins[i].PartOffset;
assert(VA.getValVT().isVector() || ArgPartOffset == 0);
while (i + 1 != e && Ins[i + 1].OrigArgIndex == ArgIndex) {
CCValAssign &PartVA = ArgLocs[i + 1];
unsigned PartOffset = Ins[i + 1].PartOffset - ArgPartOffset;
SDValue Offset = DAG.getIntPtrConstant(PartOffset, DL);
if (PartVA.getValVT().isScalableVector())
Offset = DAG.getNode(ISD::VSCALE, DL, XLenVT, Offset);
SDValue Address = DAG.getNode(ISD::ADD, DL, PtrVT, ArgValue, Offset);
InVals.push_back(DAG.getLoad(PartVA.getValVT(), DL, Chain, Address,
MachinePointerInfo()));
++i;
}
continue;
}
InVals.push_back(ArgValue);
}
if (any_of(ArgLocs,
[](CCValAssign &VA) { return VA.getLocVT().isScalableVector(); }))
MF.getInfo<RISCVMachineFunctionInfo>()->setIsVectorCall();
if (IsVarArg) {
ArrayRef<MCPhysReg> ArgRegs = ArrayRef(ArgGPRs);
unsigned Idx = CCInfo.getFirstUnallocated(ArgRegs);
const TargetRegisterClass *RC = &RISCV::GPRRegClass;
MachineFrameInfo &MFI = MF.getFrameInfo();
MachineRegisterInfo &RegInfo = MF.getRegInfo();
RISCVMachineFunctionInfo *RVFI = MF.getInfo<RISCVMachineFunctionInfo>();
// Offset of the first variable argument from stack pointer, and size of
// the vararg save area. For now, the varargs save area is either zero or
// large enough to hold a0-a7.
int VaArgOffset, VarArgsSaveSize;
// If all registers are allocated, then all varargs must be passed on the
// stack and we don't need to save any argregs.
if (ArgRegs.size() == Idx) {
VaArgOffset = CCInfo.getNextStackOffset();
VarArgsSaveSize = 0;
} else {
VarArgsSaveSize = XLenInBytes * (ArgRegs.size() - Idx);
VaArgOffset = -VarArgsSaveSize;
}
// Record the frame index of the first variable argument
// which is a value necessary to VASTART.
int FI = MFI.CreateFixedObject(XLenInBytes, VaArgOffset, true);
RVFI->setVarArgsFrameIndex(FI);
// If saving an odd number of registers then create an extra stack slot to
// ensure that the frame pointer is 2*XLEN-aligned, which in turn ensures
// offsets to even-numbered registered remain 2*XLEN-aligned.
if (Idx % 2) {
MFI.CreateFixedObject(XLenInBytes, VaArgOffset - (int)XLenInBytes, true);
VarArgsSaveSize += XLenInBytes;
}
// Copy the integer registers that may have been used for passing varargs
// to the vararg save area.
for (unsigned I = Idx; I < ArgRegs.size();
++I, VaArgOffset += XLenInBytes) {
const Register Reg = RegInfo.createVirtualRegister(RC);
RegInfo.addLiveIn(ArgRegs[I], Reg);
SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, XLenVT);
FI = MFI.CreateFixedObject(XLenInBytes, VaArgOffset, true);
SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
SDValue Store = DAG.getStore(Chain, DL, ArgValue, PtrOff,
MachinePointerInfo::getFixedStack(MF, FI));
cast<StoreSDNode>(Store.getNode())
->getMemOperand()
->setValue((Value *)nullptr);
OutChains.push_back(Store);
}
RVFI->setVarArgsSaveSize(VarArgsSaveSize);
}
// All stores are grouped in one node to allow the matching between
// the size of Ins and InVals. This only happens for vararg functions.
if (!OutChains.empty()) {
OutChains.push_back(Chain);
Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
}
return Chain;
}
/// isEligibleForTailCallOptimization - Check whether the call is eligible
/// for tail call optimization.
/// Note: This is modelled after ARM's IsEligibleForTailCallOptimization.
bool RISCVTargetLowering::isEligibleForTailCallOptimization(
CCState &CCInfo, CallLoweringInfo &CLI, MachineFunction &MF,
const SmallVector<CCValAssign, 16> &ArgLocs) const {
auto CalleeCC = CLI.CallConv;
auto &Outs = CLI.Outs;
auto &Caller = MF.getFunction();
auto CallerCC = Caller.getCallingConv();
// Exception-handling functions need a special set of instructions to
// indicate a return to the hardware. Tail-calling another function would
// probably break this.
// TODO: The "interrupt" attribute isn't currently defined by RISC-V. This
// should be expanded as new function attributes are introduced.
if (Caller.hasFnAttribute("interrupt"))
return false;
// Do not tail call opt if the stack is used to pass parameters.
if (CCInfo.getNextStackOffset() != 0)
return false;
// Do not tail call opt if any parameters need to be passed indirectly.
// Since long doubles (fp128) and i128 are larger than 2*XLEN, they are
// passed indirectly. So the address of the value will be passed in a
// register, or if not available, then the address is put on the stack. In
// order to pass indirectly, space on the stack often needs to be allocated
// in order to store the value. In this case the CCInfo.getNextStackOffset()
// != 0 check is not enough and we need to check if any CCValAssign ArgsLocs
// are passed CCValAssign::Indirect.
for (auto &VA : ArgLocs)
if (VA.getLocInfo() == CCValAssign::Indirect)
return false;
// Do not tail call opt if either caller or callee uses struct return
// semantics.
auto IsCallerStructRet = Caller.hasStructRetAttr();
auto IsCalleeStructRet = Outs.empty() ? false : Outs[0].Flags.isSRet();
if (IsCallerStructRet || IsCalleeStructRet)
return false;
// The callee has to preserve all registers the caller needs to preserve.
const RISCVRegisterInfo *TRI = Subtarget.getRegisterInfo();
const uint32_t *CallerPreserved = TRI->getCallPreservedMask(MF, CallerCC);
if (CalleeCC != CallerCC) {
const uint32_t *CalleePreserved = TRI->getCallPreservedMask(MF, CalleeCC);
if (!TRI->regmaskSubsetEqual(CallerPreserved, CalleePreserved))
return false;
}
// Byval parameters hand the function a pointer directly into the stack area
// we want to reuse during a tail call. Working around this *is* possible
// but less efficient and uglier in LowerCall.
for (auto &Arg : Outs)
if (Arg.Flags.isByVal())
return false;
return true;
}
static Align getPrefTypeAlign(EVT VT, SelectionDAG &DAG) {
return DAG.getDataLayout().getPrefTypeAlign(
VT.getTypeForEVT(*DAG.getContext()));
}
// Lower a call to a callseq_start + CALL + callseq_end chain, and add input
// and output parameter nodes.
SDValue RISCVTargetLowering::LowerCall(CallLoweringInfo &CLI,
SmallVectorImpl<SDValue> &InVals) const {
SelectionDAG &DAG = CLI.DAG;
SDLoc &DL = CLI.DL;
SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
SmallVectorImpl<SDValue> &OutVals = CLI.OutVals;
SmallVectorImpl<ISD::InputArg> &Ins = CLI.Ins;
SDValue Chain = CLI.Chain;
SDValue Callee = CLI.Callee;
bool &IsTailCall = CLI.IsTailCall;
CallingConv::ID CallConv = CLI.CallConv;
bool IsVarArg = CLI.IsVarArg;
EVT PtrVT = getPointerTy(DAG.getDataLayout());
MVT XLenVT = Subtarget.getXLenVT();
MachineFunction &MF = DAG.getMachineFunction();
// Analyze the operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState ArgCCInfo(CallConv, IsVarArg, MF, ArgLocs, *DAG.getContext());
if (CallConv == CallingConv::GHC)
ArgCCInfo.AnalyzeCallOperands(Outs, CC_RISCV_GHC);
else
analyzeOutputArgs(MF, ArgCCInfo, Outs, /*IsRet=*/false, &CLI,
CallConv == CallingConv::Fast ? CC_RISCV_FastCC
: CC_RISCV);
// Check if it's really possible to do a tail call.
if (IsTailCall)
IsTailCall = isEligibleForTailCallOptimization(ArgCCInfo, CLI, MF, ArgLocs);
if (IsTailCall)
++NumTailCalls;
else if (CLI.CB && CLI.CB->isMustTailCall())
report_fatal_error("failed to perform tail call elimination on a call "
"site marked musttail");
// Get a count of how many bytes are to be pushed on the stack.
unsigned NumBytes = ArgCCInfo.getNextStackOffset();
// Create local copies for byval args
SmallVector<SDValue, 8> ByValArgs;
for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
ISD::ArgFlagsTy Flags = Outs[i].Flags;
if (!Flags.isByVal())
continue;
SDValue Arg = OutVals[i];
unsigned Size = Flags.getByValSize();
Align Alignment = Flags.getNonZeroByValAlign();
int FI =
MF.getFrameInfo().CreateStackObject(Size, Alignment, /*isSS=*/false);
SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
SDValue SizeNode = DAG.getConstant(Size, DL, XLenVT);
Chain = DAG.getMemcpy(Chain, DL, FIPtr, Arg, SizeNode, Alignment,
/*IsVolatile=*/false,
/*AlwaysInline=*/false, IsTailCall,
MachinePointerInfo(), MachinePointerInfo());
ByValArgs.push_back(FIPtr);
}
if (!IsTailCall)
Chain = DAG.getCALLSEQ_START(Chain, NumBytes, 0, CLI.DL);
// Copy argument values to their designated locations.
SmallVector<std::pair<Register, SDValue>, 8> RegsToPass;
SmallVector<SDValue, 8> MemOpChains;
SDValue StackPtr;
for (unsigned i = 0, j = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
SDValue ArgValue = OutVals[i];
ISD::ArgFlagsTy Flags = Outs[i].Flags;
// Handle passing f64 on RV32D with a soft float ABI as a special case.
bool IsF64OnRV32DSoftABI =
VA.getLocVT() == MVT::i32 && VA.getValVT() == MVT::f64;
if (IsF64OnRV32DSoftABI && VA.isRegLoc()) {
SDValue SplitF64 = DAG.getNode(
RISCVISD::SplitF64, DL, DAG.getVTList(MVT::i32, MVT::i32), ArgValue);
SDValue Lo = SplitF64.getValue(0);
SDValue Hi = SplitF64.getValue(1);
Register RegLo = VA.getLocReg();
RegsToPass.push_back(std::make_pair(RegLo, Lo));
if (RegLo == RISCV::X17) {
// Second half of f64 is passed on the stack.
// Work out the address of the stack slot.
if (!StackPtr.getNode())
StackPtr = DAG.getCopyFromReg(Chain, DL, RISCV::X2, PtrVT);
// Emit the store.
MemOpChains.push_back(
DAG.getStore(Chain, DL, Hi, StackPtr, MachinePointerInfo()));
} else {
// Second half of f64 is passed in another GPR.
assert(RegLo < RISCV::X31 && "Invalid register pair");
Register RegHigh = RegLo + 1;
RegsToPass.push_back(std::make_pair(RegHigh, Hi));
}
continue;
}
// IsF64OnRV32DSoftABI && VA.isMemLoc() is handled below in the same way
// as any other MemLoc.
// Promote the value if needed.
// For now, only handle fully promoted and indirect arguments.
if (VA.getLocInfo() == CCValAssign::Indirect) {
// Store the argument in a stack slot and pass its address.
Align StackAlign =
std::max(getPrefTypeAlign(Outs[i].ArgVT, DAG),
getPrefTypeAlign(ArgValue.getValueType(), DAG));
TypeSize StoredSize = ArgValue.getValueType().getStoreSize();
// If the original argument was split (e.g. i128), we need
// to store the required parts of it here (and pass just one address).
// Vectors may be partly split to registers and partly to the stack, in
// which case the base address is partly offset and subsequent stores are
// relative to that.
unsigned ArgIndex = Outs[i].OrigArgIndex;
unsigned ArgPartOffset = Outs[i].PartOffset;
assert(VA.getValVT().isVector() || ArgPartOffset == 0);
// Calculate the total size to store. We don't have access to what we're
// actually storing other than performing the loop and collecting the
// info.
SmallVector<std::pair<SDValue, SDValue>> Parts;
while (i + 1 != e && Outs[i + 1].OrigArgIndex == ArgIndex) {
SDValue PartValue = OutVals[i + 1];
unsigned PartOffset = Outs[i + 1].PartOffset - ArgPartOffset;
SDValue Offset = DAG.getIntPtrConstant(PartOffset, DL);
EVT PartVT = PartValue.getValueType();
if (PartVT.isScalableVector())
Offset = DAG.getNode(ISD::VSCALE, DL, XLenVT, Offset);
StoredSize += PartVT.getStoreSize();
StackAlign = std::max(StackAlign, getPrefTypeAlign(PartVT, DAG));
Parts.push_back(std::make_pair(PartValue, Offset));
++i;
}
SDValue SpillSlot = DAG.CreateStackTemporary(StoredSize, StackAlign);
int FI = cast<FrameIndexSDNode>(SpillSlot)->getIndex();
MemOpChains.push_back(
DAG.getStore(Chain, DL, ArgValue, SpillSlot,
MachinePointerInfo::getFixedStack(MF, FI)));
for (const auto &Part : Parts) {
SDValue PartValue = Part.first;
SDValue PartOffset = Part.second;
SDValue Address =
DAG.getNode(ISD::ADD, DL, PtrVT, SpillSlot, PartOffset);
MemOpChains.push_back(
DAG.getStore(Chain, DL, PartValue, Address,
MachinePointerInfo::getFixedStack(MF, FI)));
}
ArgValue = SpillSlot;
} else {
ArgValue = convertValVTToLocVT(DAG, ArgValue, VA, DL, Subtarget);
}
// Use local copy if it is a byval arg.
if (Flags.isByVal())
ArgValue = ByValArgs[j++];
if (VA.isRegLoc()) {
// Queue up the argument copies and emit them at the end.
RegsToPass.push_back(std::make_pair(VA.getLocReg(), ArgValue));
} else {
assert(VA.isMemLoc() && "Argument not register or memory");
assert(!IsTailCall && "Tail call not allowed if stack is used "
"for passing parameters");
// Work out the address of the stack slot.
if (!StackPtr.getNode())
StackPtr = DAG.getCopyFromReg(Chain, DL, RISCV::X2, PtrVT);
SDValue Address =
DAG.getNode(ISD::ADD, DL, PtrVT, StackPtr,
DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
// Emit the store.
MemOpChains.push_back(
DAG.getStore(Chain, DL, ArgValue, Address, MachinePointerInfo()));
}
}
// Join the stores, which are independent of one another.
if (!MemOpChains.empty())
Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
SDValue Glue;
// Build a sequence of copy-to-reg nodes, chained and glued together.
for (auto &Reg : RegsToPass) {
Chain = DAG.getCopyToReg(Chain, DL, Reg.first, Reg.second, Glue);
Glue = Chain.getValue(1);
}
// Validate that none of the argument registers have been marked as
// reserved, if so report an error. Do the same for the return address if this
// is not a tailcall.
validateCCReservedRegs(RegsToPass, MF);
if (!IsTailCall &&
MF.getSubtarget<RISCVSubtarget>().isRegisterReservedByUser(RISCV::X1))
MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
MF.getFunction(),
"Return address register required, but has been reserved."});
// If the callee is a GlobalAddress/ExternalSymbol node, turn it into a
// TargetGlobalAddress/TargetExternalSymbol node so that legalize won't
// split it and then direct call can be matched by PseudoCALL.
if (GlobalAddressSDNode *S = dyn_cast<GlobalAddressSDNode>(Callee)) {
const GlobalValue *GV = S->getGlobal();
unsigned OpFlags = RISCVII::MO_CALL;
if (!getTargetMachine().shouldAssumeDSOLocal(*GV->getParent(), GV))
OpFlags = RISCVII::MO_PLT;
Callee = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, OpFlags);
} else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
unsigned OpFlags = RISCVII::MO_CALL;
if (!getTargetMachine().shouldAssumeDSOLocal(*MF.getFunction().getParent(),
nullptr))
OpFlags = RISCVII::MO_PLT;
Callee = DAG.getTargetExternalSymbol(S->getSymbol(), PtrVT, OpFlags);
}
// The first call operand is the chain and the second is the target address.
SmallVector<SDValue, 8> Ops;
Ops.push_back(Chain);
Ops.push_back(Callee);
// Add argument registers to the end of the list so that they are
// known live into the call.
for (auto &Reg : RegsToPass)
Ops.push_back(DAG.getRegister(Reg.first, Reg.second.getValueType()));
if (!IsTailCall) {
// Add a register mask operand representing the call-preserved registers.
const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
const uint32_t *Mask = TRI->getCallPreservedMask(MF, CallConv);
assert(Mask && "Missing call preserved mask for calling convention");
Ops.push_back(DAG.getRegisterMask(Mask));
}
// Glue the call to the argument copies, if any.
if (Glue.getNode())
Ops.push_back(Glue);
// Emit the call.
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
if (IsTailCall) {
MF.getFrameInfo().setHasTailCall();
return DAG.getNode(RISCVISD::TAIL, DL, NodeTys, Ops);
}
Chain = DAG.getNode(RISCVISD::CALL, DL, NodeTys, Ops);
DAG.addNoMergeSiteInfo(Chain.getNode(), CLI.NoMerge);
Glue = Chain.getValue(1);
// Mark the end of the call, which is glued to the call itself.
Chain = DAG.getCALLSEQ_END(Chain, NumBytes, 0, Glue, DL);
Glue = Chain.getValue(1);
// Assign locations to each value returned by this call.
SmallVector<CCValAssign, 16> RVLocs;
CCState RetCCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
analyzeInputArgs(MF, RetCCInfo, Ins, /*IsRet=*/true, CC_RISCV);
// Copy all of the result registers out of their specified physreg.
for (auto &VA : RVLocs) {
// Copy the value out
SDValue RetValue =
DAG.getCopyFromReg(Chain, DL, VA.getLocReg(), VA.getLocVT(), Glue);
// Glue the RetValue to the end of the call sequence
Chain = RetValue.getValue(1);
Glue = RetValue.getValue(2);
if (VA.getLocVT() == MVT::i32 && VA.getValVT() == MVT::f64) {
assert(VA.getLocReg() == ArgGPRs[0] && "Unexpected reg assignment");
SDValue RetValue2 =
DAG.getCopyFromReg(Chain, DL, ArgGPRs[1], MVT::i32, Glue);
Chain = RetValue2.getValue(1);
Glue = RetValue2.getValue(2);
RetValue = DAG.getNode(RISCVISD::BuildPairF64, DL, MVT::f64, RetValue,
RetValue2);
}
RetValue = convertLocVTToValVT(DAG, RetValue, VA, DL, Subtarget);
InVals.push_back(RetValue);
}
return Chain;
}
bool RISCVTargetLowering::CanLowerReturn(
CallingConv::ID CallConv, MachineFunction &MF, bool IsVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs, LLVMContext &Context) const {
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
std::optional<unsigned> FirstMaskArgument;
if (Subtarget.hasVInstructions())
FirstMaskArgument = preAssignMask(Outs);
for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
MVT VT = Outs[i].VT;
ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
RISCVABI::ABI ABI = MF.getSubtarget<RISCVSubtarget>().getTargetABI();
if (CC_RISCV(MF.getDataLayout(), ABI, i, VT, VT, CCValAssign::Full,
ArgFlags, CCInfo, /*IsFixed=*/true, /*IsRet=*/true, nullptr,
*this, FirstMaskArgument))
return false;
}
return true;
}
SDValue
RISCVTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
bool IsVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SDLoc &DL, SelectionDAG &DAG) const {
MachineFunction &MF = DAG.getMachineFunction();
const RISCVSubtarget &STI = MF.getSubtarget<RISCVSubtarget>();
// Stores the assignment of the return value to a location.
SmallVector<CCValAssign, 16> RVLocs;
// Info about the registers and stack slot.
CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
*DAG.getContext());
analyzeOutputArgs(DAG.getMachineFunction(), CCInfo, Outs, /*IsRet=*/true,
nullptr, CC_RISCV);
if (CallConv == CallingConv::GHC && !RVLocs.empty())
report_fatal_error("GHC functions return void only");
SDValue Glue;
SmallVector<SDValue, 4> RetOps(1, Chain);
// Copy the result values into the output registers.
for (unsigned i = 0, e = RVLocs.size(); i < e; ++i) {
SDValue Val = OutVals[i];
CCValAssign &VA = RVLocs[i];
assert(VA.isRegLoc() && "Can only return in registers!");
if (VA.getLocVT() == MVT::i32 && VA.getValVT() == MVT::f64) {
// Handle returning f64 on RV32D with a soft float ABI.
assert(VA.isRegLoc() && "Expected return via registers");
SDValue SplitF64 = DAG.getNode(RISCVISD::SplitF64, DL,
DAG.getVTList(MVT::i32, MVT::i32), Val);
SDValue Lo = SplitF64.getValue(0);
SDValue Hi = SplitF64.getValue(1);
Register RegLo = VA.getLocReg();
assert(RegLo < RISCV::X31 && "Invalid register pair");
Register RegHi = RegLo + 1;
if (STI.isRegisterReservedByUser(RegLo) ||
STI.isRegisterReservedByUser(RegHi))
MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
MF.getFunction(),
"Return value register required, but has been reserved."});
Chain = DAG.getCopyToReg(Chain, DL, RegLo, Lo, Glue);
Glue = Chain.getValue(1);
RetOps.push_back(DAG.getRegister(RegLo, MVT::i32));
Chain = DAG.getCopyToReg(Chain, DL, RegHi, Hi, Glue);
Glue = Chain.getValue(1);
RetOps.push_back(DAG.getRegister(RegHi, MVT::i32));
} else {
// Handle a 'normal' return.
Val = convertValVTToLocVT(DAG, Val, VA, DL, Subtarget);
Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Glue);
if (STI.isRegisterReservedByUser(VA.getLocReg()))
MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
MF.getFunction(),
"Return value register required, but has been reserved."});
// Guarantee that all emitted copies are stuck together.
Glue = Chain.getValue(1);
RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
}
}
RetOps[0] = Chain; // Update chain.
// Add the glue node if we have it.
if (Glue.getNode()) {
RetOps.push_back(Glue);
}
if (any_of(RVLocs,
[](CCValAssign &VA) { return VA.getLocVT().isScalableVector(); }))
MF.getInfo<RISCVMachineFunctionInfo>()->setIsVectorCall();
unsigned RetOpc = RISCVISD::RET_GLUE;
// Interrupt service routines use different return instructions.
const Function &Func = DAG.getMachineFunction().getFunction();
if (Func.hasFnAttribute("interrupt")) {
if (!Func.getReturnType()->isVoidTy())
report_fatal_error(
"Functions with the interrupt attribute must have void return type!");
MachineFunction &MF = DAG.getMachineFunction();
StringRef Kind =
MF.getFunction().getFnAttribute("interrupt").getValueAsString();
if (Kind == "user")
RetOpc = RISCVISD::URET_GLUE;
else if (Kind == "supervisor")
RetOpc = RISCVISD::SRET_GLUE;
else
RetOpc = RISCVISD::MRET_GLUE;
}
return DAG.getNode(RetOpc, DL, MVT::Other, RetOps);
}
void RISCVTargetLowering::validateCCReservedRegs(
const SmallVectorImpl<std::pair<llvm::Register, llvm::SDValue>> &Regs,
MachineFunction &MF) const {
const Function &F = MF.getFunction();
const RISCVSubtarget &STI = MF.getSubtarget<RISCVSubtarget>();
if (llvm::any_of(Regs, [&STI](auto Reg) {
return STI.isRegisterReservedByUser(Reg.first);
}))
F.getContext().diagnose(DiagnosticInfoUnsupported{
F, "Argument register required, but has been reserved."});
}
// Check if the result of the node is only used as a return value, as
// otherwise we can't perform a tail-call.
bool RISCVTargetLowering::isUsedByReturnOnly(SDNode *N, SDValue &Chain) const {
if (N->getNumValues() != 1)
return false;
if (!N->hasNUsesOfValue(1, 0))
return false;
SDNode *Copy = *N->use_begin();
if (Copy->getOpcode() == ISD::BITCAST) {
return isUsedByReturnOnly(Copy, Chain);
}
// TODO: Handle additional opcodes in order to support tail-calling libcalls
// with soft float ABIs.
if (Copy->getOpcode() != ISD::CopyToReg) {
return false;
}
// If the ISD::CopyToReg has a glue operand, we conservatively assume it
// isn't safe to perform a tail call.
if (Copy->getOperand(Copy->getNumOperands() - 1).getValueType() == MVT::Glue)
return false;
// The copy must be used by a RISCVISD::RET_GLUE, and nothing else.
bool HasRet = false;
for (SDNode *Node : Copy->uses()) {
if (Node->getOpcode() != RISCVISD::RET_GLUE)
return false;
HasRet = true;
}
if (!HasRet)
return false;
Chain = Copy->getOperand(0);
return true;
}
bool RISCVTargetLowering::mayBeEmittedAsTailCall(const CallInst *CI) const {
return CI->isTailCall();
}
const char *RISCVTargetLowering::getTargetNodeName(unsigned Opcode) const {
#define NODE_NAME_CASE(NODE) \
case RISCVISD::NODE: \
return "RISCVISD::" #NODE;
// clang-format off
switch ((RISCVISD::NodeType)Opcode) {
case RISCVISD::FIRST_NUMBER:
break;
NODE_NAME_CASE(RET_GLUE)
NODE_NAME_CASE(URET_GLUE)
NODE_NAME_CASE(SRET_GLUE)
NODE_NAME_CASE(MRET_GLUE)
NODE_NAME_CASE(CALL)
NODE_NAME_CASE(SELECT_CC)
NODE_NAME_CASE(BR_CC)
NODE_NAME_CASE(BuildPairF64)
NODE_NAME_CASE(SplitF64)
NODE_NAME_CASE(TAIL)
NODE_NAME_CASE(ADD_LO)
NODE_NAME_CASE(HI)
NODE_NAME_CASE(LLA)
NODE_NAME_CASE(ADD_TPREL)
NODE_NAME_CASE(LA)
NODE_NAME_CASE(LA_TLS_IE)
NODE_NAME_CASE(LA_TLS_GD)
NODE_NAME_CASE(MULHSU)
NODE_NAME_CASE(SLLW)
NODE_NAME_CASE(SRAW)
NODE_NAME_CASE(SRLW)
NODE_NAME_CASE(DIVW)
NODE_NAME_CASE(DIVUW)
NODE_NAME_CASE(REMUW)
NODE_NAME_CASE(ROLW)
NODE_NAME_CASE(RORW)
NODE_NAME_CASE(CLZW)
NODE_NAME_CASE(CTZW)
NODE_NAME_CASE(ABSW)
NODE_NAME_CASE(FMV_H_X)
NODE_NAME_CASE(FMV_X_ANYEXTH)
NODE_NAME_CASE(FMV_X_SIGNEXTH)
NODE_NAME_CASE(FMV_W_X_RV64)
NODE_NAME_CASE(FMV_X_ANYEXTW_RV64)
NODE_NAME_CASE(FCVT_X)
NODE_NAME_CASE(FCVT_XU)
NODE_NAME_CASE(FCVT_W_RV64)
NODE_NAME_CASE(FCVT_WU_RV64)
NODE_NAME_CASE(STRICT_FCVT_W_RV64)
NODE_NAME_CASE(STRICT_FCVT_WU_RV64)
NODE_NAME_CASE(FROUND)
NODE_NAME_CASE(READ_CYCLE_WIDE)
NODE_NAME_CASE(BREV8)
NODE_NAME_CASE(ORC_B)
NODE_NAME_CASE(ZIP)
NODE_NAME_CASE(UNZIP)
NODE_NAME_CASE(TH_LWD)
NODE_NAME_CASE(TH_LWUD)
NODE_NAME_CASE(TH_LDD)
NODE_NAME_CASE(TH_SWD)
NODE_NAME_CASE(TH_SDD)
NODE_NAME_CASE(VMV_V_X_VL)
NODE_NAME_CASE(VFMV_V_F_VL)
NODE_NAME_CASE(VMV_X_S)
NODE_NAME_CASE(VMV_S_X_VL)
NODE_NAME_CASE(VFMV_S_F_VL)
NODE_NAME_CASE(SPLAT_VECTOR_SPLIT_I64_VL)
NODE_NAME_CASE(READ_VLENB)
NODE_NAME_CASE(TRUNCATE_VECTOR_VL)
NODE_NAME_CASE(VSLIDEUP_VL)
NODE_NAME_CASE(VSLIDE1UP_VL)
NODE_NAME_CASE(VSLIDEDOWN_VL)
NODE_NAME_CASE(VSLIDE1DOWN_VL)
NODE_NAME_CASE(VID_VL)
NODE_NAME_CASE(VFNCVT_ROD_VL)
NODE_NAME_CASE(VECREDUCE_ADD_VL)
NODE_NAME_CASE(VECREDUCE_UMAX_VL)
NODE_NAME_CASE(VECREDUCE_SMAX_VL)
NODE_NAME_CASE(VECREDUCE_UMIN_VL)
NODE_NAME_CASE(VECREDUCE_SMIN_VL)
NODE_NAME_CASE(VECREDUCE_AND_VL)
NODE_NAME_CASE(VECREDUCE_OR_VL)
NODE_NAME_CASE(VECREDUCE_XOR_VL)
NODE_NAME_CASE(VECREDUCE_FADD_VL)
NODE_NAME_CASE(VECREDUCE_SEQ_FADD_VL)
NODE_NAME_CASE(VECREDUCE_FMIN_VL)
NODE_NAME_CASE(VECREDUCE_FMAX_VL)
NODE_NAME_CASE(ADD_VL)
NODE_NAME_CASE(AND_VL)
NODE_NAME_CASE(MUL_VL)
NODE_NAME_CASE(OR_VL)
NODE_NAME_CASE(SDIV_VL)
NODE_NAME_CASE(SHL_VL)
NODE_NAME_CASE(SREM_VL)
NODE_NAME_CASE(SRA_VL)
NODE_NAME_CASE(SRL_VL)
NODE_NAME_CASE(SUB_VL)
NODE_NAME_CASE(UDIV_VL)
NODE_NAME_CASE(UREM_VL)
NODE_NAME_CASE(XOR_VL)
NODE_NAME_CASE(SADDSAT_VL)
NODE_NAME_CASE(UADDSAT_VL)
NODE_NAME_CASE(SSUBSAT_VL)
NODE_NAME_CASE(USUBSAT_VL)
NODE_NAME_CASE(FADD_VL)
NODE_NAME_CASE(FSUB_VL)
NODE_NAME_CASE(FMUL_VL)
NODE_NAME_CASE(FDIV_VL)
NODE_NAME_CASE(FNEG_VL)
NODE_NAME_CASE(FABS_VL)
NODE_NAME_CASE(FSQRT_VL)
NODE_NAME_CASE(VFMADD_VL)
NODE_NAME_CASE(VFNMADD_VL)
NODE_NAME_CASE(VFMSUB_VL)
NODE_NAME_CASE(VFNMSUB_VL)
NODE_NAME_CASE(FCOPYSIGN_VL)
NODE_NAME_CASE(SMIN_VL)
NODE_NAME_CASE(SMAX_VL)
NODE_NAME_CASE(UMIN_VL)
NODE_NAME_CASE(UMAX_VL)
NODE_NAME_CASE(FMINNUM_VL)
NODE_NAME_CASE(FMAXNUM_VL)
NODE_NAME_CASE(MULHS_VL)
NODE_NAME_CASE(MULHU_VL)
NODE_NAME_CASE(VFCVT_RTZ_X_F_VL)
NODE_NAME_CASE(VFCVT_RTZ_XU_F_VL)
NODE_NAME_CASE(VFCVT_RM_X_F_VL)
NODE_NAME_CASE(VFCVT_RM_XU_F_VL)
NODE_NAME_CASE(VFCVT_X_F_VL)
NODE_NAME_CASE(VFCVT_XU_F_VL)
NODE_NAME_CASE(VFROUND_NOEXCEPT_VL)
NODE_NAME_CASE(SINT_TO_FP_VL)
NODE_NAME_CASE(UINT_TO_FP_VL)
NODE_NAME_CASE(VFCVT_RM_F_XU_VL)
NODE_NAME_CASE(VFCVT_RM_F_X_VL)
NODE_NAME_CASE(FP_EXTEND_VL)
NODE_NAME_CASE(FP_ROUND_VL)
NODE_NAME_CASE(STRICT_FADD_VL)
NODE_NAME_CASE(STRICT_FSUB_VL)
NODE_NAME_CASE(STRICT_FMUL_VL)
NODE_NAME_CASE(STRICT_FDIV_VL)
NODE_NAME_CASE(STRICT_FSQRT_VL)
NODE_NAME_CASE(STRICT_VFMADD_VL)
NODE_NAME_CASE(STRICT_VFNMADD_VL)
NODE_NAME_CASE(STRICT_VFMSUB_VL)
NODE_NAME_CASE(STRICT_VFNMSUB_VL)
NODE_NAME_CASE(STRICT_FP_ROUND_VL)
NODE_NAME_CASE(STRICT_FP_EXTEND_VL)
NODE_NAME_CASE(STRICT_VFNCVT_ROD_VL)
NODE_NAME_CASE(STRICT_SINT_TO_FP_VL)
NODE_NAME_CASE(STRICT_UINT_TO_FP_VL)
NODE_NAME_CASE(STRICT_VFCVT_RTZ_X_F_VL)
NODE_NAME_CASE(STRICT_VFCVT_RTZ_XU_F_VL)
NODE_NAME_CASE(STRICT_FSETCC_VL)
NODE_NAME_CASE(STRICT_FSETCCS_VL)
NODE_NAME_CASE(VWMUL_VL)
NODE_NAME_CASE(VWMULU_VL)
NODE_NAME_CASE(VWMULSU_VL)
NODE_NAME_CASE(VWADD_VL)
NODE_NAME_CASE(VWADDU_VL)
NODE_NAME_CASE(VWSUB_VL)
NODE_NAME_CASE(VWSUBU_VL)
NODE_NAME_CASE(VWADD_W_VL)
NODE_NAME_CASE(VWADDU_W_VL)
NODE_NAME_CASE(VWSUB_W_VL)
NODE_NAME_CASE(VWSUBU_W_VL)
NODE_NAME_CASE(VNSRL_VL)
NODE_NAME_CASE(SETCC_VL)
NODE_NAME_CASE(VSELECT_VL)
NODE_NAME_CASE(VP_MERGE_VL)
NODE_NAME_CASE(VMAND_VL)
NODE_NAME_CASE(VMOR_VL)
NODE_NAME_CASE(VMXOR_VL)
NODE_NAME_CASE(VMCLR_VL)
NODE_NAME_CASE(VMSET_VL)
NODE_NAME_CASE(VRGATHER_VX_VL)
NODE_NAME_CASE(VRGATHER_VV_VL)
NODE_NAME_CASE(VRGATHEREI16_VV_VL)
NODE_NAME_CASE(VSEXT_VL)
NODE_NAME_CASE(VZEXT_VL)
NODE_NAME_CASE(VCPOP_VL)
NODE_NAME_CASE(VFIRST_VL)
NODE_NAME_CASE(READ_CSR)
NODE_NAME_CASE(WRITE_CSR)
NODE_NAME_CASE(SWAP_CSR)
}
// clang-format on
return nullptr;
#undef NODE_NAME_CASE
}
/// getConstraintType - Given a constraint letter, return the type of
/// constraint it is for this target.
RISCVTargetLowering::ConstraintType
RISCVTargetLowering::getConstraintType(StringRef Constraint) const {
if (Constraint.size() == 1) {
switch (Constraint[0]) {
default:
break;
case 'f':
return C_RegisterClass;
case 'I':
case 'J':
case 'K':
return C_Immediate;
case 'A':
return C_Memory;
case 'S': // A symbolic address
return C_Other;
}
} else {
if (Constraint == "vr" || Constraint == "vm")
return C_RegisterClass;
}
return TargetLowering::getConstraintType(Constraint);
}
std::pair<unsigned, const TargetRegisterClass *>
RISCVTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
StringRef Constraint,
MVT VT) const {
// First, see if this is a constraint that directly corresponds to a RISC-V
// register class.
if (Constraint.size() == 1) {
switch (Constraint[0]) {
case 'r':
// TODO: Support fixed vectors up to XLen for P extension?
if (VT.isVector())
break;
return std::make_pair(0U, &RISCV::GPRRegClass);
case 'f':
if (Subtarget.hasStdExtZfhOrZfhmin() && VT == MVT::f16)
return std::make_pair(0U, &RISCV::FPR16RegClass);
if (Subtarget.hasStdExtF() && VT == MVT::f32)
return std::make_pair(0U, &RISCV::FPR32RegClass);
if (Subtarget.hasStdExtD() && VT == MVT::f64)
return std::make_pair(0U, &RISCV::FPR64RegClass);
break;
default:
break;
}
} else if (Constraint == "vr") {
for (const auto *RC : {&RISCV::VRRegClass, &RISCV::VRM2RegClass,
&RISCV::VRM4RegClass, &RISCV::VRM8RegClass}) {
if (TRI->isTypeLegalForClass(*RC, VT.SimpleTy))
return std::make_pair(0U, RC);
}
} else if (Constraint == "vm") {
if (TRI->isTypeLegalForClass(RISCV::VMV0RegClass, VT.SimpleTy))
return std::make_pair(0U, &RISCV::VMV0RegClass);
}
// Clang will correctly decode the usage of register name aliases into their
// official names. However, other frontends like `rustc` do not. This allows
// users of these frontends to use the ABI names for registers in LLVM-style
// register constraints.
unsigned XRegFromAlias = StringSwitch<unsigned>(Constraint.lower())
.Case("{zero}", RISCV::X0)
.Case("{ra}", RISCV::X1)
.Case("{sp}", RISCV::X2)
.Case("{gp}", RISCV::X3)
.Case("{tp}", RISCV::X4)
.Case("{t0}", RISCV::X5)
.Case("{t1}", RISCV::X6)
.Case("{t2}", RISCV::X7)
.Cases("{s0}", "{fp}", RISCV::X8)
.Case("{s1}", RISCV::X9)
.Case("{a0}", RISCV::X10)
.Case("{a1}", RISCV::X11)
.Case("{a2}", RISCV::X12)
.Case("{a3}", RISCV::X13)
.Case("{a4}", RISCV::X14)
.Case("{a5}", RISCV::X15)
.Case("{a6}", RISCV::X16)
.Case("{a7}", RISCV::X17)
.Case("{s2}", RISCV::X18)
.Case("{s3}", RISCV::X19)
.Case("{s4}", RISCV::X20)
.Case("{s5}", RISCV::X21)
.Case("{s6}", RISCV::X22)
.Case("{s7}", RISCV::X23)
.Case("{s8}", RISCV::X24)
.Case("{s9}", RISCV::X25)
.Case("{s10}", RISCV::X26)
.Case("{s11}", RISCV::X27)
.Case("{t3}", RISCV::X28)
.Case("{t4}", RISCV::X29)
.Case("{t5}", RISCV::X30)
.Case("{t6}", RISCV::X31)
.Default(RISCV::NoRegister);
if (XRegFromAlias != RISCV::NoRegister)
return std::make_pair(XRegFromAlias, &RISCV::GPRRegClass);
// Since TargetLowering::getRegForInlineAsmConstraint uses the name of the
// TableGen record rather than the AsmName to choose registers for InlineAsm
// constraints, plus we want to match those names to the widest floating point
// register type available, manually select floating point registers here.
//
// The second case is the ABI name of the register, so that frontends can also
// use the ABI names in register constraint lists.
if (Subtarget.hasStdExtF()) {
unsigned FReg = StringSwitch<unsigned>(Constraint.lower())
.Cases("{f0}", "{ft0}", RISCV::F0_F)
.Cases("{f1}", "{ft1}", RISCV::F1_F)
.Cases("{f2}", "{ft2}", RISCV::F2_F)
.Cases("{f3}", "{ft3}", RISCV::F3_F)
.Cases("{f4}", "{ft4}", RISCV::F4_F)
.Cases("{f5}", "{ft5}", RISCV::F5_F)
.Cases("{f6}", "{ft6}", RISCV::F6_F)
.Cases("{f7}", "{ft7}", RISCV::F7_F)
.Cases("{f8}", "{fs0}", RISCV::F8_F)
.Cases("{f9}", "{fs1}", RISCV::F9_F)
.Cases("{f10}", "{fa0}", RISCV::F10_F)
.Cases("{f11}", "{fa1}", RISCV::F11_F)
.Cases("{f12}", "{fa2}", RISCV::F12_F)
.Cases("{f13}", "{fa3}", RISCV::F13_F)
.Cases("{f14}", "{fa4}", RISCV::F14_F)
.Cases("{f15}", "{fa5}", RISCV::F15_F)
.Cases("{f16}", "{fa6}", RISCV::F16_F)
.Cases("{f17}", "{fa7}", RISCV::F17_F)
.Cases("{f18}", "{fs2}", RISCV::F18_F)
.Cases("{f19}", "{fs3}", RISCV::F19_F)
.Cases("{f20}", "{fs4}", RISCV::F20_F)
.Cases("{f21}", "{fs5}", RISCV::F21_F)
.Cases("{f22}", "{fs6}", RISCV::F22_F)
.Cases("{f23}", "{fs7}", RISCV::F23_F)
.Cases("{f24}", "{fs8}", RISCV::F24_F)
.Cases("{f25}", "{fs9}", RISCV::F25_F)
.Cases("{f26}", "{fs10}", RISCV::F26_F)
.Cases("{f27}", "{fs11}", RISCV::F27_F)
.Cases("{f28}", "{ft8}", RISCV::F28_F)
.Cases("{f29}", "{ft9}", RISCV::F29_F)
.Cases("{f30}", "{ft10}", RISCV::F30_F)
.Cases("{f31}", "{ft11}", RISCV::F31_F)
.Default(RISCV::NoRegister);
if (FReg != RISCV::NoRegister) {
assert(RISCV::F0_F <= FReg && FReg <= RISCV::F31_F && "Unknown fp-reg");
if (Subtarget.hasStdExtD() && (VT == MVT::f64 || VT == MVT::Other)) {
unsigned RegNo = FReg - RISCV::F0_F;
unsigned DReg = RISCV::F0_D + RegNo;
return std::make_pair(DReg, &RISCV::FPR64RegClass);
}
if (VT == MVT::f32 || VT == MVT::Other)
return std::make_pair(FReg, &RISCV::FPR32RegClass);
if (Subtarget.hasStdExtZfhOrZfhmin() && VT == MVT::f16) {
unsigned RegNo = FReg - RISCV::F0_F;
unsigned HReg = RISCV::F0_H + RegNo;
return std::make_pair(HReg, &RISCV::FPR16RegClass);
}
}
}
if (Subtarget.hasVInstructions()) {
Register VReg = StringSwitch<Register>(Constraint.lower())
.Case("{v0}", RISCV::V0)
.Case("{v1}", RISCV::V1)
.Case("{v2}", RISCV::V2)
.Case("{v3}", RISCV::V3)
.Case("{v4}", RISCV::V4)
.Case("{v5}", RISCV::V5)
.Case("{v6}", RISCV::V6)
.Case("{v7}", RISCV::V7)
.Case("{v8}", RISCV::V8)
.Case("{v9}", RISCV::V9)
.Case("{v10}", RISCV::V10)
.Case("{v11}", RISCV::V11)
.Case("{v12}", RISCV::V12)
.Case("{v13}", RISCV::V13)
.Case("{v14}", RISCV::V14)
.Case("{v15}", RISCV::V15)
.Case("{v16}", RISCV::V16)
.Case("{v17}", RISCV::V17)
.Case("{v18}", RISCV::V18)
.Case("{v19}", RISCV::V19)
.Case("{v20}", RISCV::V20)
.Case("{v21}", RISCV::V21)
.Case("{v22}", RISCV::V22)
.Case("{v23}", RISCV::V23)
.Case("{v24}", RISCV::V24)
.Case("{v25}", RISCV::V25)
.Case("{v26}", RISCV::V26)
.Case("{v27}", RISCV::V27)
.Case("{v28}", RISCV::V28)
.Case("{v29}", RISCV::V29)
.Case("{v30}", RISCV::V30)
.Case("{v31}", RISCV::V31)
.Default(RISCV::NoRegister);
if (VReg != RISCV::NoRegister) {
if (TRI->isTypeLegalForClass(RISCV::VMRegClass, VT.SimpleTy))
return std::make_pair(VReg, &RISCV::VMRegClass);
if (TRI->isTypeLegalForClass(RISCV::VRRegClass, VT.SimpleTy))
return std::make_pair(VReg, &RISCV::VRRegClass);
for (const auto *RC :
{&RISCV::VRM2RegClass, &RISCV::VRM4RegClass, &RISCV::VRM8RegClass}) {
if (TRI->isTypeLegalForClass(*RC, VT.SimpleTy)) {
VReg = TRI->getMatchingSuperReg(VReg, RISCV::sub_vrm1_0, RC);
return std::make_pair(VReg, RC);
}
}
}
}
std::pair<Register, const TargetRegisterClass *> Res =
TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
// If we picked one of the Zfinx register classes, remap it to the GPR class.
// FIXME: When Zfinx is supported in CodeGen this will need to take the
// Subtarget into account.
if (Res.second == &RISCV::GPRF16RegClass ||
Res.second == &RISCV::GPRF32RegClass ||
Res.second == &RISCV::GPRF64RegClass)
return std::make_pair(Res.first, &RISCV::GPRRegClass);
return Res;
}
unsigned
RISCVTargetLowering::getInlineAsmMemConstraint(StringRef ConstraintCode) const {
// Currently only support length 1 constraints.
if (ConstraintCode.size() == 1) {
switch (ConstraintCode[0]) {
case 'A':
return InlineAsm::Constraint_A;
default:
break;
}
}
return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
}
void RISCVTargetLowering::LowerAsmOperandForConstraint(
SDValue Op, std::string &Constraint, std::vector<SDValue> &Ops,
SelectionDAG &DAG) const {
// Currently only support length 1 constraints.
if (Constraint.length() == 1) {
switch (Constraint[0]) {
case 'I':
// Validate & create a 12-bit signed immediate operand.
if (auto *C = dyn_cast<ConstantSDNode>(Op)) {
uint64_t CVal = C->getSExtValue();
if (isInt<12>(CVal))
Ops.push_back(
DAG.getTargetConstant(CVal, SDLoc(Op), Subtarget.getXLenVT()));
}
return;
case 'J':
// Validate & create an integer zero operand.
if (isNullConstant(Op))
Ops.push_back(
DAG.getTargetConstant(0, SDLoc(Op), Subtarget.getXLenVT()));
return;
case 'K':
// Validate & create a 5-bit unsigned immediate operand.
if (auto *C = dyn_cast<ConstantSDNode>(Op)) {
uint64_t CVal = C->getZExtValue();
if (isUInt<5>(CVal))
Ops.push_back(
DAG.getTargetConstant(CVal, SDLoc(Op), Subtarget.getXLenVT()));
}
return;
case 'S':
if (const auto *GA = dyn_cast<GlobalAddressSDNode>(Op)) {
Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(), SDLoc(Op),
GA->getValueType(0)));
} else if (const auto *BA = dyn_cast<BlockAddressSDNode>(Op)) {
Ops.push_back(DAG.getTargetBlockAddress(BA->getBlockAddress(),
BA->getValueType(0)));
}
return;
default:
break;
}
}
TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
}
Instruction *RISCVTargetLowering::emitLeadingFence(IRBuilderBase &Builder,
Instruction *Inst,
AtomicOrdering Ord) const {
if (Subtarget.hasStdExtZtso()) {
if (isa<LoadInst>(Inst) && Ord == AtomicOrdering::SequentiallyConsistent)
return Builder.CreateFence(Ord);
return nullptr;
}
if (isa<LoadInst>(Inst) && Ord == AtomicOrdering::SequentiallyConsistent)
return Builder.CreateFence(Ord);
if (isa<StoreInst>(Inst) && isReleaseOrStronger(Ord))
return Builder.CreateFence(AtomicOrdering::Release);
return nullptr;
}
Instruction *RISCVTargetLowering::emitTrailingFence(IRBuilderBase &Builder,
Instruction *Inst,
AtomicOrdering Ord) const {
if (Subtarget.hasStdExtZtso())
return nullptr;
if (isa<LoadInst>(Inst) && isAcquireOrStronger(Ord))
return Builder.CreateFence(AtomicOrdering::Acquire);
return nullptr;
}
TargetLowering::AtomicExpansionKind
RISCVTargetLowering::shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const {
// atomicrmw {fadd,fsub} must be expanded to use compare-exchange, as floating
// point operations can't be used in an lr/sc sequence without breaking the
// forward-progress guarantee.
if (AI->isFloatingPointOperation() ||
AI->getOperation() == AtomicRMWInst::UIncWrap ||
AI->getOperation() == AtomicRMWInst::UDecWrap)
return AtomicExpansionKind::CmpXChg;
// Don't expand forced atomics, we want to have __sync libcalls instead.
if (Subtarget.hasForcedAtomics())
return AtomicExpansionKind::None;
unsigned Size = AI->getType()->getPrimitiveSizeInBits();
if (Size == 8 || Size == 16)
return AtomicExpansionKind::MaskedIntrinsic;
return AtomicExpansionKind::None;
}
static Intrinsic::ID
getIntrinsicForMaskedAtomicRMWBinOp(unsigned XLen, AtomicRMWInst::BinOp BinOp) {
if (XLen == 32) {
switch (BinOp) {
default:
llvm_unreachable("Unexpected AtomicRMW BinOp");
case AtomicRMWInst::Xchg:
return Intrinsic::riscv_masked_atomicrmw_xchg_i32;
case AtomicRMWInst::Add:
return Intrinsic::riscv_masked_atomicrmw_add_i32;
case AtomicRMWInst::Sub:
return Intrinsic::riscv_masked_atomicrmw_sub_i32;
case AtomicRMWInst::Nand:
return Intrinsic::riscv_masked_atomicrmw_nand_i32;
case AtomicRMWInst::Max:
return Intrinsic::riscv_masked_atomicrmw_max_i32;
case AtomicRMWInst::Min:
return Intrinsic::riscv_masked_atomicrmw_min_i32;
case AtomicRMWInst::UMax:
return Intrinsic::riscv_masked_atomicrmw_umax_i32;
case AtomicRMWInst::UMin:
return Intrinsic::riscv_masked_atomicrmw_umin_i32;
}
}
if (XLen == 64) {
switch (BinOp) {
default:
llvm_unreachable("Unexpected AtomicRMW BinOp");
case AtomicRMWInst::Xchg:
return Intrinsic::riscv_masked_atomicrmw_xchg_i64;
case AtomicRMWInst::Add:
return Intrinsic::riscv_masked_atomicrmw_add_i64;
case AtomicRMWInst::Sub:
return Intrinsic::riscv_masked_atomicrmw_sub_i64;
case AtomicRMWInst::Nand:
return Intrinsic::riscv_masked_atomicrmw_nand_i64;
case AtomicRMWInst::Max:
return Intrinsic::riscv_masked_atomicrmw_max_i64;
case AtomicRMWInst::Min:
return Intrinsic::riscv_masked_atomicrmw_min_i64;
case AtomicRMWInst::UMax:
return Intrinsic::riscv_masked_atomicrmw_umax_i64;
case AtomicRMWInst::UMin:
return Intrinsic::riscv_masked_atomicrmw_umin_i64;
}
}
llvm_unreachable("Unexpected XLen\n");
}
Value *RISCVTargetLowering::emitMaskedAtomicRMWIntrinsic(
IRBuilderBase &Builder, AtomicRMWInst *AI, Value *AlignedAddr, Value *Incr,
Value *Mask, Value *ShiftAmt, AtomicOrdering Ord) const {
unsigned XLen = Subtarget.getXLen();
Value *Ordering =
Builder.getIntN(XLen, static_cast<uint64_t>(AI->getOrdering()));
Type *Tys[] = {AlignedAddr->getType()};
Function *LrwOpScwLoop = Intrinsic::getDeclaration(
AI->getModule(),
getIntrinsicForMaskedAtomicRMWBinOp(XLen, AI->getOperation()), Tys);
if (XLen == 64) {
Incr = Builder.CreateSExt(Incr, Builder.getInt64Ty());
Mask = Builder.CreateSExt(Mask, Builder.getInt64Ty());
ShiftAmt = Builder.CreateSExt(ShiftAmt, Builder.getInt64Ty());
}
Value *Result;
// Must pass the shift amount needed to sign extend the loaded value prior
// to performing a signed comparison for min/max. ShiftAmt is the number of
// bits to shift the value into position. Pass XLen-ShiftAmt-ValWidth, which
// is the number of bits to left+right shift the value in order to
// sign-extend.
if (AI->getOperation() == AtomicRMWInst::Min ||
AI->getOperation() == AtomicRMWInst::Max) {
const DataLayout &DL = AI->getModule()->getDataLayout();
unsigned ValWidth =
DL.getTypeStoreSizeInBits(AI->getValOperand()->getType());
Value *SextShamt =
Builder.CreateSub(Builder.getIntN(XLen, XLen - ValWidth), ShiftAmt);
Result = Builder.CreateCall(LrwOpScwLoop,
{AlignedAddr, Incr, Mask, SextShamt, Ordering});
} else {
Result =
Builder.CreateCall(LrwOpScwLoop, {AlignedAddr, Incr, Mask, Ordering});
}
if (XLen == 64)
Result = Builder.CreateTrunc(Result, Builder.getInt32Ty());
return Result;
}
TargetLowering::AtomicExpansionKind
RISCVTargetLowering::shouldExpandAtomicCmpXchgInIR(
AtomicCmpXchgInst *CI) const {
// Don't expand forced atomics, we want to have __sync libcalls instead.
if (Subtarget.hasForcedAtomics())
return AtomicExpansionKind::None;
unsigned Size = CI->getCompareOperand()->getType()->getPrimitiveSizeInBits();
if (Size == 8 || Size == 16)
return AtomicExpansionKind::MaskedIntrinsic;
return AtomicExpansionKind::None;
}
Value *RISCVTargetLowering::emitMaskedAtomicCmpXchgIntrinsic(
IRBuilderBase &Builder, AtomicCmpXchgInst *CI, Value *AlignedAddr,
Value *CmpVal, Value *NewVal, Value *Mask, AtomicOrdering Ord) const {
unsigned XLen = Subtarget.getXLen();
Value *Ordering = Builder.getIntN(XLen, static_cast<uint64_t>(Ord));
Intrinsic::ID CmpXchgIntrID = Intrinsic::riscv_masked_cmpxchg_i32;
if (XLen == 64) {
CmpVal = Builder.CreateSExt(CmpVal, Builder.getInt64Ty());
NewVal = Builder.CreateSExt(NewVal, Builder.getInt64Ty());
Mask = Builder.CreateSExt(Mask, Builder.getInt64Ty());
CmpXchgIntrID = Intrinsic::riscv_masked_cmpxchg_i64;
}
Type *Tys[] = {AlignedAddr->getType()};
Function *MaskedCmpXchg =
Intrinsic::getDeclaration(CI->getModule(), CmpXchgIntrID, Tys);
Value *Result = Builder.CreateCall(
MaskedCmpXchg, {AlignedAddr, CmpVal, NewVal, Mask, Ordering});
if (XLen == 64)
Result = Builder.CreateTrunc(Result, Builder.getInt32Ty());
return Result;
}
bool RISCVTargetLowering::shouldRemoveExtendFromGSIndex(EVT IndexVT,
EVT DataVT) const {
return false;
}
bool RISCVTargetLowering::shouldConvertFpToSat(unsigned Op, EVT FPVT,
EVT VT) const {
if (!isOperationLegalOrCustom(Op, VT) || !FPVT.isSimple())
return false;
switch (FPVT.getSimpleVT().SimpleTy) {
case MVT::f16:
return Subtarget.hasStdExtZfhOrZfhmin();
case MVT::f32:
return Subtarget.hasStdExtF();
case MVT::f64:
return Subtarget.hasStdExtD();
default:
return false;
}
}
unsigned RISCVTargetLowering::getJumpTableEncoding() const {
// If we are using the small code model, we can reduce size of jump table
// entry to 4 bytes.
if (Subtarget.is64Bit() && !isPositionIndependent() &&
getTargetMachine().getCodeModel() == CodeModel::Small) {
return MachineJumpTableInfo::EK_Custom32;
}
return TargetLowering::getJumpTableEncoding();
}
const MCExpr *RISCVTargetLowering::LowerCustomJumpTableEntry(
const MachineJumpTableInfo *MJTI, const MachineBasicBlock *MBB,
unsigned uid, MCContext &Ctx) const {
assert(Subtarget.is64Bit() && !isPositionIndependent() &&
getTargetMachine().getCodeModel() == CodeModel::Small);
return MCSymbolRefExpr::create(MBB->getSymbol(), Ctx);
}
bool RISCVTargetLowering::isVScaleKnownToBeAPowerOfTwo() const {
// We define vscale to be VLEN/RVVBitsPerBlock. VLEN is always a power
// of two >= 64, and RVVBitsPerBlock is 64. Thus, vscale must be
// a power of two as well.
// FIXME: This doesn't work for zve32, but that's already broken
// elsewhere for the same reason.
assert(Subtarget.getRealMinVLen() >= 64 && "zve32* unsupported");
static_assert(RISCV::RVVBitsPerBlock == 64,
"RVVBitsPerBlock changed, audit needed");
return true;
}
bool RISCVTargetLowering::getIndexedAddressParts(SDNode *Op, SDValue &Base,
SDValue &Offset,
ISD::MemIndexedMode &AM,
bool &IsInc,
SelectionDAG &DAG) const {
// Target does not support indexed loads.
if (!Subtarget.hasVendorXTHeadMemIdx())
return false;
if (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB)
return false;
Base = Op->getOperand(0);
if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Op->getOperand(1))) {
int64_t RHSC = RHS->getSExtValue();
if (Op->getOpcode() == ISD::SUB)
RHSC = -(uint64_t)RHSC;
// The constants that can be encoded in the THeadMemIdx instructions
// are of the form (sign_extend(imm5) << imm2).
bool isLegalIndexedOffset = false;
for (unsigned i = 0; i < 4; i++)
if (isInt<5>(RHSC >> i) && ((RHSC % (1LL << i)) == 0)) {
isLegalIndexedOffset = true;
break;
}
if (!isLegalIndexedOffset)
return false;
IsInc = (Op->getOpcode() == ISD::ADD);
Offset = Op->getOperand(1);
return true;
}
return false;
}
bool RISCVTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
SDValue &Offset,
ISD::MemIndexedMode &AM,
SelectionDAG &DAG) const {
EVT VT;
SDValue Ptr;
if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
VT = LD->getMemoryVT();
Ptr = LD->getBasePtr();
} else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
VT = ST->getMemoryVT();
Ptr = ST->getBasePtr();
} else
return false;
bool IsInc;
if (!getIndexedAddressParts(Ptr.getNode(), Base, Offset, AM, IsInc, DAG))
return false;
AM = IsInc ? ISD::PRE_INC : ISD::PRE_DEC;
return true;
}
bool RISCVTargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
SDValue &Base,
SDValue &Offset,
ISD::MemIndexedMode &AM,
SelectionDAG &DAG) const {
EVT VT;
SDValue Ptr;
if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
VT = LD->getMemoryVT();
Ptr = LD->getBasePtr();
} else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
VT = ST->getMemoryVT();
Ptr = ST->getBasePtr();
} else
return false;
bool IsInc;
if (!getIndexedAddressParts(Op, Base, Offset, AM, IsInc, DAG))
return false;
// Post-indexing updates the base, so it's not a valid transform
// if that's not the same as the load's pointer.
if (Ptr != Base)
return false;
AM = IsInc ? ISD::POST_INC : ISD::POST_DEC;
return true;
}
bool RISCVTargetLowering::isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,
EVT VT) const {
EVT SVT = VT.getScalarType();
if (!SVT.isSimple())
return false;
switch (SVT.getSimpleVT().SimpleTy) {
case MVT::f16:
return VT.isVector() ? Subtarget.hasVInstructionsF16()
: Subtarget.hasStdExtZfh();
case MVT::f32:
return Subtarget.hasStdExtF();
case MVT::f64:
return Subtarget.hasStdExtD();
default:
break;
}
return false;
}
Register RISCVTargetLowering::getExceptionPointerRegister(
const Constant *PersonalityFn) const {
return RISCV::X10;
}
Register RISCVTargetLowering::getExceptionSelectorRegister(
const Constant *PersonalityFn) const {
return RISCV::X11;
}
bool RISCVTargetLowering::shouldExtendTypeInLibCall(EVT Type) const {
// Return false to suppress the unnecessary extensions if the LibCall
// arguments or return value is f32 type for LP64 ABI.
RISCVABI::ABI ABI = Subtarget.getTargetABI();
if (ABI == RISCVABI::ABI_LP64 && (Type == MVT::f32))
return false;
return true;
}
bool RISCVTargetLowering::shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const {
if (Subtarget.is64Bit() && Type == MVT::i32)
return true;
return IsSigned;
}
bool RISCVTargetLowering::decomposeMulByConstant(LLVMContext &Context, EVT VT,
SDValue C) const {
// Check integral scalar types.
const bool HasExtMOrZmmul =
Subtarget.hasStdExtM() || Subtarget.hasStdExtZmmul();
if (VT.isScalarInteger()) {
// Omit the optimization if the sub target has the M extension and the data
// size exceeds XLen.
if (HasExtMOrZmmul && VT.getSizeInBits() > Subtarget.getXLen())
return false;
if (auto *ConstNode = dyn_cast<ConstantSDNode>(C.getNode())) {
// Break the MUL to a SLLI and an ADD/SUB.
const APInt &Imm = ConstNode->getAPIntValue();
if ((Imm + 1).isPowerOf2() || (Imm - 1).isPowerOf2() ||
(1 - Imm).isPowerOf2() || (-1 - Imm).isPowerOf2())
return true;
// Optimize the MUL to (SH*ADD x, (SLLI x, bits)) if Imm is not simm12.
if (Subtarget.hasStdExtZba() && !Imm.isSignedIntN(12) &&
((Imm - 2).isPowerOf2() || (Imm - 4).isPowerOf2() ||
(Imm - 8).isPowerOf2()))
return true;
// Break the MUL to two SLLI instructions and an ADD/SUB, if Imm needs
// a pair of LUI/ADDI.
if (!Imm.isSignedIntN(12) && Imm.countr_zero() < 12 &&
ConstNode->hasOneUse()) {
APInt ImmS = Imm.ashr(Imm.countr_zero());
if ((ImmS + 1).isPowerOf2() || (ImmS - 1).isPowerOf2() ||
(1 - ImmS).isPowerOf2())
return true;
}
}
}
return false;
}
bool RISCVTargetLowering::isMulAddWithConstProfitable(SDValue AddNode,
SDValue ConstNode) const {
// Let the DAGCombiner decide for vectors.
EVT VT = AddNode.getValueType();
if (VT.isVector())
return true;
// Let the DAGCombiner decide for larger types.
if (VT.getScalarSizeInBits() > Subtarget.getXLen())
return true;
// It is worse if c1 is simm12 while c1*c2 is not.
ConstantSDNode *C1Node = cast<ConstantSDNode>(AddNode.getOperand(1));
ConstantSDNode *C2Node = cast<ConstantSDNode>(ConstNode);
const APInt &C1 = C1Node->getAPIntValue();
const APInt &C2 = C2Node->getAPIntValue();
if (C1.isSignedIntN(12) && !(C1 * C2).isSignedIntN(12))
return false;
// Default to true and let the DAGCombiner decide.
return true;
}
bool RISCVTargetLowering::allowsMisalignedMemoryAccesses(
EVT VT, unsigned AddrSpace, Align Alignment, MachineMemOperand::Flags Flags,
unsigned *Fast) const {
if (!VT.isVector()) {
if (Fast)
*Fast = 0;
return Subtarget.enableUnalignedScalarMem();
}
// All vector implementations must support element alignment
EVT ElemVT = VT.getVectorElementType();
if (Alignment >= ElemVT.getStoreSize()) {
if (Fast)
*Fast = 1;
return true;
}
return false;
}
bool RISCVTargetLowering::splitValueIntoRegisterParts(
SelectionDAG &DAG, const SDLoc &DL, SDValue Val, SDValue *Parts,
unsigned NumParts, MVT PartVT, std::optional<CallingConv::ID> CC) const {
bool IsABIRegCopy = CC.has_value();
EVT ValueVT = Val.getValueType();
if (IsABIRegCopy && ValueVT == MVT::f16 && PartVT == MVT::f32) {
// Cast the f16 to i16, extend to i32, pad with ones to make a float nan,
// and cast to f32.
Val = DAG.getNode(ISD::BITCAST, DL, MVT::i16, Val);
Val = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i32, Val);
Val = DAG.getNode(ISD::OR, DL, MVT::i32, Val,
DAG.getConstant(0xFFFF0000, DL, MVT::i32));
Val = DAG.getNode(ISD::BITCAST, DL, MVT::f32, Val);
Parts[0] = Val;
return true;
}
if (ValueVT.isScalableVector() && PartVT.isScalableVector()) {
LLVMContext &Context = *DAG.getContext();
EVT ValueEltVT = ValueVT.getVectorElementType();
EVT PartEltVT = PartVT.getVectorElementType();
unsigned ValueVTBitSize = ValueVT.getSizeInBits().getKnownMinValue();
unsigned PartVTBitSize = PartVT.getSizeInBits().getKnownMinValue();
if (PartVTBitSize % ValueVTBitSize == 0) {
assert(PartVTBitSize >= ValueVTBitSize);
// If the element types are different, bitcast to the same element type of
// PartVT first.
// Give an example here, we want copy a <vscale x 1 x i8> value to
// <vscale x 4 x i16>.
// We need to convert <vscale x 1 x i8> to <vscale x 8 x i8> by insert
// subvector, then we can bitcast to <vscale x 4 x i16>.
if (ValueEltVT != PartEltVT) {
if (PartVTBitSize > ValueVTBitSize) {
unsigned Count = PartVTBitSize / ValueEltVT.getFixedSizeInBits();
assert(Count != 0 && "The number of element should not be zero.");
EVT SameEltTypeVT =
EVT::getVectorVT(Context, ValueEltVT, Count, /*IsScalable=*/true);
Val = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, SameEltTypeVT,
DAG.getUNDEF(SameEltTypeVT), Val,
DAG.getVectorIdxConstant(0, DL));
}
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
} else {
Val =
DAG.getNode(ISD::INSERT_SUBVECTOR, DL, PartVT, DAG.getUNDEF(PartVT),
Val, DAG.getVectorIdxConstant(0, DL));
}
Parts[0] = Val;
return true;
}
}
return false;
}
SDValue RISCVTargetLowering::joinRegisterPartsIntoValue(
SelectionDAG &DAG, const SDLoc &DL, const SDValue *Parts, unsigned NumParts,
MVT PartVT, EVT ValueVT, std::optional<CallingConv::ID> CC) const {
bool IsABIRegCopy = CC.has_value();
if (IsABIRegCopy && ValueVT == MVT::f16 && PartVT == MVT::f32) {
SDValue Val = Parts[0];
// Cast the f32 to i32, truncate to i16, and cast back to f16.
Val = DAG.getNode(ISD::BITCAST, DL, MVT::i32, Val);
Val = DAG.getNode(ISD::TRUNCATE, DL, MVT::i16, Val);
Val = DAG.getNode(ISD::BITCAST, DL, MVT::f16, Val);
return Val;
}
if (ValueVT.isScalableVector() && PartVT.isScalableVector()) {
LLVMContext &Context = *DAG.getContext();
SDValue Val = Parts[0];
EVT ValueEltVT = ValueVT.getVectorElementType();
EVT PartEltVT = PartVT.getVectorElementType();
unsigned ValueVTBitSize = ValueVT.getSizeInBits().getKnownMinValue();
unsigned PartVTBitSize = PartVT.getSizeInBits().getKnownMinValue();
if (PartVTBitSize % ValueVTBitSize == 0) {
assert(PartVTBitSize >= ValueVTBitSize);
EVT SameEltTypeVT = ValueVT;
// If the element types are different, convert it to the same element type
// of PartVT.
// Give an example here, we want copy a <vscale x 1 x i8> value from
// <vscale x 4 x i16>.
// We need to convert <vscale x 4 x i16> to <vscale x 8 x i8> first,
// then we can extract <vscale x 1 x i8>.
if (ValueEltVT != PartEltVT) {
unsigned Count = PartVTBitSize / ValueEltVT.getFixedSizeInBits();
assert(Count != 0 && "The number of element should not be zero.");
SameEltTypeVT =
EVT::getVectorVT(Context, ValueEltVT, Count, /*IsScalable=*/true);
Val = DAG.getNode(ISD::BITCAST, DL, SameEltTypeVT, Val);
}
Val = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, ValueVT, Val,
DAG.getVectorIdxConstant(0, DL));
return Val;
}
}
return SDValue();
}
bool RISCVTargetLowering::isIntDivCheap(EVT VT, AttributeList Attr) const {
// When aggressively optimizing for code size, we prefer to use a div
// instruction, as it is usually smaller than the alternative sequence.
// TODO: Add vector division?
bool OptSize = Attr.hasFnAttr(Attribute::MinSize);
return OptSize && !VT.isVector();
}
bool RISCVTargetLowering::preferScalarizeSplat(SDNode *N) const {
// Scalarize zero_ext and sign_ext might stop match to widening instruction in
// some situation.
unsigned Opc = N->getOpcode();
if (Opc == ISD::ZERO_EXTEND || Opc == ISD::SIGN_EXTEND)
return false;
return true;
}
static Value *useTpOffset(IRBuilderBase &IRB, unsigned Offset) {
Module *M = IRB.GetInsertBlock()->getParent()->getParent();
Function *ThreadPointerFunc =
Intrinsic::getDeclaration(M, Intrinsic::thread_pointer);
return IRB.CreatePointerCast(
IRB.CreateConstGEP1_32(IRB.getInt8Ty(),
IRB.CreateCall(ThreadPointerFunc), Offset),
IRB.getInt8PtrTy()->getPointerTo(0));
}
Value *RISCVTargetLowering::getIRStackGuard(IRBuilderBase &IRB) const {
// Fuchsia provides a fixed TLS slot for the stack cookie.
// <zircon/tls.h> defines ZX_TLS_STACK_GUARD_OFFSET with this value.
if (Subtarget.isTargetFuchsia())
return useTpOffset(IRB, -0x10);
return TargetLowering::getIRStackGuard(IRB);
}
bool RISCVTargetLowering::isLegalInterleavedAccessType(
FixedVectorType *VTy, unsigned Factor, const DataLayout &DL) const {
if (!Subtarget.useRVVForFixedLengthVectors())
return false;
if (!isLegalElementTypeForRVV(VTy->getElementType()))
return false;
EVT VT = getValueType(DL, VTy);
// Don't lower vlseg/vsseg for fixed length vector types that can't be split.
if (!isTypeLegal(VT))
return false;
// Sometimes the interleaved access pass picks up splats as interleaves of one
// element. Don't lower these.
if (VTy->getNumElements() < 2)
return false;
// Need to make sure that EMUL * NFIELDS ≤ 8
MVT ContainerVT = getContainerForFixedLengthVector(VT.getSimpleVT());
auto [LMUL, Fractional] = RISCVVType::decodeVLMUL(getLMUL(ContainerVT));
if (Fractional)
return true;
return Factor * LMUL <= 8;
}
/// Lower an interleaved load into a vlsegN intrinsic.
///
/// E.g. Lower an interleaved load (Factor = 2):
/// %wide.vec = load <8 x i32>, <8 x i32>* %ptr
/// %v0 = shuffle %wide.vec, undef, <0, 2, 4, 6> ; Extract even elements
/// %v1 = shuffle %wide.vec, undef, <1, 3, 5, 7> ; Extract odd elements
///
/// Into:
/// %ld2 = { <4 x i32>, <4 x i32> } call llvm.riscv.vlseg.v4i32.p0.i64(
/// %ptr, i64 4)
/// %vec0 = extractelement { <4 x i32>, <4 x i32> } %ld2, i32 0
/// %vec1 = extractelement { <4 x i32>, <4 x i32> } %ld2, i32 1
bool RISCVTargetLowering::lowerInterleavedLoad(
LoadInst *LI, ArrayRef<ShuffleVectorInst *> Shuffles,
ArrayRef<unsigned> Indices, unsigned Factor) const {
IRBuilder<> Builder(LI);
auto *VTy = cast<FixedVectorType>(Shuffles[0]->getType());
if (!isLegalInterleavedAccessType(VTy, Factor,
LI->getModule()->getDataLayout()))
return false;
auto *XLenTy = Type::getIntNTy(LI->getContext(), Subtarget.getXLen());
static const Intrinsic::ID FixedLenIntrIds[] = {
Intrinsic::riscv_seg2_load, Intrinsic::riscv_seg3_load,
Intrinsic::riscv_seg4_load, Intrinsic::riscv_seg5_load,
Intrinsic::riscv_seg6_load, Intrinsic::riscv_seg7_load,
Intrinsic::riscv_seg8_load};
Function *VlsegNFunc =
Intrinsic::getDeclaration(LI->getModule(), FixedLenIntrIds[Factor - 2],
{VTy, LI->getPointerOperandType(), XLenTy});
Value *VL = ConstantInt::get(XLenTy, VTy->getNumElements());
CallInst *VlsegN =
Builder.CreateCall(VlsegNFunc, {LI->getPointerOperand(), VL});
for (unsigned i = 0; i < Shuffles.size(); i++) {
Value *SubVec = Builder.CreateExtractValue(VlsegN, Indices[i]);
Shuffles[i]->replaceAllUsesWith(SubVec);
}
return true;
}
/// Lower an interleaved store into a vssegN intrinsic.
///
/// E.g. Lower an interleaved store (Factor = 3):
/// %i.vec = shuffle <8 x i32> %v0, <8 x i32> %v1,
/// <0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 11>
/// store <12 x i32> %i.vec, <12 x i32>* %ptr
///
/// Into:
/// %sub.v0 = shuffle <8 x i32> %v0, <8 x i32> v1, <0, 1, 2, 3>
/// %sub.v1 = shuffle <8 x i32> %v0, <8 x i32> v1, <4, 5, 6, 7>
/// %sub.v2 = shuffle <8 x i32> %v0, <8 x i32> v1, <8, 9, 10, 11>
/// call void llvm.riscv.vsseg3.v4i32.p0.i64(%sub.v0, %sub.v1, %sub.v2,
/// %ptr, i32 4)
///
/// Note that the new shufflevectors will be removed and we'll only generate one
/// vsseg3 instruction in CodeGen.
bool RISCVTargetLowering::lowerInterleavedStore(StoreInst *SI,
ShuffleVectorInst *SVI,
unsigned Factor) const {
IRBuilder<> Builder(SI);
auto *ShuffleVTy = cast<FixedVectorType>(SVI->getType());
// Given SVI : <n*factor x ty>, then VTy : <n x ty>
auto *VTy = FixedVectorType::get(ShuffleVTy->getElementType(),
ShuffleVTy->getNumElements() / Factor);
if (!isLegalInterleavedAccessType(VTy, Factor,
SI->getModule()->getDataLayout()))
return false;
auto *XLenTy = Type::getIntNTy(SI->getContext(), Subtarget.getXLen());
static const Intrinsic::ID FixedLenIntrIds[] = {
Intrinsic::riscv_seg2_store, Intrinsic::riscv_seg3_store,
Intrinsic::riscv_seg4_store, Intrinsic::riscv_seg5_store,
Intrinsic::riscv_seg6_store, Intrinsic::riscv_seg7_store,
Intrinsic::riscv_seg8_store};
Function *VssegNFunc =
Intrinsic::getDeclaration(SI->getModule(), FixedLenIntrIds[Factor - 2],
{VTy, SI->getPointerOperandType(), XLenTy});
auto Mask = SVI->getShuffleMask();
SmallVector<Value *, 10> Ops;
for (unsigned i = 0; i < Factor; i++) {
Value *Shuffle = Builder.CreateShuffleVector(
SVI->getOperand(0), SVI->getOperand(1),
createSequentialMask(Mask[i], VTy->getNumElements(), 0));
Ops.push_back(Shuffle);
}
// This VL should be OK (should be executable in one vsseg instruction,
// potentially under larger LMULs) because we checked that the fixed vector
// type fits in isLegalInterleavedAccessType
Value *VL = ConstantInt::get(XLenTy, VTy->getNumElements());
Ops.append({SI->getPointerOperand(), VL});
Builder.CreateCall(VssegNFunc, Ops);
return true;
}
#define GET_REGISTER_MATCHER
#include "RISCVGenAsmMatcher.inc"
Register
RISCVTargetLowering::getRegisterByName(const char *RegName, LLT VT,
const MachineFunction &MF) const {
Register Reg = MatchRegisterAltName(RegName);
if (Reg == RISCV::NoRegister)
Reg = MatchRegisterName(RegName);
if (Reg == RISCV::NoRegister)
report_fatal_error(
Twine("Invalid register name \"" + StringRef(RegName) + "\"."));
BitVector ReservedRegs = Subtarget.getRegisterInfo()->getReservedRegs(MF);
if (!ReservedRegs.test(Reg) && !Subtarget.isRegisterReservedByUser(Reg))
report_fatal_error(Twine("Trying to obtain non-reserved register \"" +
StringRef(RegName) + "\"."));
return Reg;
}
namespace llvm::RISCVVIntrinsicsTable {
#define GET_RISCVVIntrinsicsTable_IMPL
#include "RISCVGenSearchableTables.inc"
} // namespace llvm::RISCVVIntrinsicsTable
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