llvm-project/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
Pierre van Houtryve 2ae8bee8f1
[ARM][GlobalISel] Remove legacy legalizer rules (#82619)
I've been looking at LegacyLegalizerInfo and what its place in GISel is.
It seems like it's very close to being deleted so I'm checking if we can
remove the last remaining uses of it.

Looks like we can do a drop-in replacement with the new legalizer for
ARM.
2024-02-23 10:28:58 +01:00

447 lines
18 KiB
C++

//===- ARMLegalizerInfo.cpp --------------------------------------*- C++ -*-==//
//
// 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
//
//===----------------------------------------------------------------------===//
/// \file
/// This file implements the targeting of the Machinelegalizer class for ARM.
/// \todo This should be generated by TableGen.
//===----------------------------------------------------------------------===//
#include "ARMLegalizerInfo.h"
#include "ARMCallLowering.h"
#include "ARMSubtarget.h"
#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/LowLevelTypeUtils.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Type.h"
using namespace llvm;
using namespace LegalizeActions;
static bool AEABI(const ARMSubtarget &ST) {
return ST.isTargetAEABI() || ST.isTargetGNUAEABI() || ST.isTargetMuslAEABI();
}
ARMLegalizerInfo::ARMLegalizerInfo(const ARMSubtarget &ST) {
using namespace TargetOpcode;
const LLT p0 = LLT::pointer(0, 32);
const LLT s1 = LLT::scalar(1);
const LLT s8 = LLT::scalar(8);
const LLT s16 = LLT::scalar(16);
const LLT s32 = LLT::scalar(32);
const LLT s64 = LLT::scalar(64);
auto &LegacyInfo = getLegacyLegalizerInfo();
if (ST.isThumb1Only()) {
// Thumb1 is not supported yet.
LegacyInfo.computeTables();
verify(*ST.getInstrInfo());
return;
}
getActionDefinitionsBuilder({G_SEXT, G_ZEXT, G_ANYEXT})
.legalForCartesianProduct({s8, s16, s32}, {s1, s8, s16});
getActionDefinitionsBuilder(G_SEXT_INREG).lower();
getActionDefinitionsBuilder({G_MUL, G_AND, G_OR, G_XOR})
.legalFor({s32})
.clampScalar(0, s32, s32);
if (ST.hasNEON())
getActionDefinitionsBuilder({G_ADD, G_SUB})
.legalFor({s32, s64})
.minScalar(0, s32);
else
getActionDefinitionsBuilder({G_ADD, G_SUB})
.legalFor({s32})
.minScalar(0, s32);
getActionDefinitionsBuilder({G_ASHR, G_LSHR, G_SHL})
.legalFor({{s32, s32}})
.minScalar(0, s32)
.clampScalar(1, s32, s32);
bool HasHWDivide = (!ST.isThumb() && ST.hasDivideInARMMode()) ||
(ST.isThumb() && ST.hasDivideInThumbMode());
if (HasHWDivide)
getActionDefinitionsBuilder({G_SDIV, G_UDIV})
.legalFor({s32})
.clampScalar(0, s32, s32);
else
getActionDefinitionsBuilder({G_SDIV, G_UDIV})
.libcallFor({s32})
.clampScalar(0, s32, s32);
auto &REMBuilder =
getActionDefinitionsBuilder({G_SREM, G_UREM}).minScalar(0, s32);
if (HasHWDivide)
REMBuilder.lowerFor({s32});
else if (AEABI(ST))
REMBuilder.customFor({s32});
else
REMBuilder.libcallFor({s32});
getActionDefinitionsBuilder(G_INTTOPTR)
.legalFor({{p0, s32}})
.minScalar(1, s32);
getActionDefinitionsBuilder(G_PTRTOINT)
.legalFor({{s32, p0}})
.minScalar(0, s32);
getActionDefinitionsBuilder(G_CONSTANT)
.legalFor({s32, p0})
.clampScalar(0, s32, s32);
getActionDefinitionsBuilder(G_ICMP)
.legalForCartesianProduct({s1}, {s32, p0})
.minScalar(1, s32);
getActionDefinitionsBuilder(G_SELECT)
.legalForCartesianProduct({s32, p0}, {s1})
.minScalar(0, s32);
// We're keeping these builders around because we'll want to add support for
// floating point to them.
auto &LoadStoreBuilder = getActionDefinitionsBuilder({G_LOAD, G_STORE})
.legalForTypesWithMemDesc({{s8, p0, s8, 8},
{s16, p0, s16, 8},
{s32, p0, s32, 8},
{p0, p0, p0, 8}})
.unsupportedIfMemSizeNotPow2();
getActionDefinitionsBuilder(G_FRAME_INDEX).legalFor({p0});
getActionDefinitionsBuilder(G_GLOBAL_VALUE).legalFor({p0});
auto &PhiBuilder =
getActionDefinitionsBuilder(G_PHI)
.legalFor({s32, p0})
.minScalar(0, s32);
getActionDefinitionsBuilder(G_PTR_ADD)
.legalFor({{p0, s32}})
.minScalar(1, s32);
getActionDefinitionsBuilder(G_BRCOND).legalFor({s1});
if (!ST.useSoftFloat() && ST.hasVFP2Base()) {
getActionDefinitionsBuilder(
{G_FADD, G_FSUB, G_FMUL, G_FDIV, G_FCONSTANT, G_FNEG})
.legalFor({s32, s64});
LoadStoreBuilder
.legalForTypesWithMemDesc({{s64, p0, s64, 32}})
.maxScalar(0, s32);
PhiBuilder.legalFor({s64});
getActionDefinitionsBuilder(G_FCMP).legalForCartesianProduct({s1},
{s32, s64});
getActionDefinitionsBuilder(G_MERGE_VALUES).legalFor({{s64, s32}});
getActionDefinitionsBuilder(G_UNMERGE_VALUES).legalFor({{s32, s64}});
getActionDefinitionsBuilder(G_FPEXT).legalFor({{s64, s32}});
getActionDefinitionsBuilder(G_FPTRUNC).legalFor({{s32, s64}});
getActionDefinitionsBuilder({G_FPTOSI, G_FPTOUI})
.legalForCartesianProduct({s32}, {s32, s64});
getActionDefinitionsBuilder({G_SITOFP, G_UITOFP})
.legalForCartesianProduct({s32, s64}, {s32});
getActionDefinitionsBuilder({G_GET_FPENV, G_SET_FPENV}).legalFor({s32});
getActionDefinitionsBuilder(G_RESET_FPENV).alwaysLegal();
} else {
getActionDefinitionsBuilder({G_FADD, G_FSUB, G_FMUL, G_FDIV})
.libcallFor({s32, s64});
LoadStoreBuilder.maxScalar(0, s32);
getActionDefinitionsBuilder(G_FNEG).lowerFor({s32, s64});
getActionDefinitionsBuilder(G_FCONSTANT).customFor({s32, s64});
getActionDefinitionsBuilder(G_FCMP).customForCartesianProduct({s1},
{s32, s64});
if (AEABI(ST))
setFCmpLibcallsAEABI();
else
setFCmpLibcallsGNU();
getActionDefinitionsBuilder(G_FPEXT).libcallFor({{s64, s32}});
getActionDefinitionsBuilder(G_FPTRUNC).libcallFor({{s32, s64}});
getActionDefinitionsBuilder({G_FPTOSI, G_FPTOUI})
.libcallForCartesianProduct({s32}, {s32, s64});
getActionDefinitionsBuilder({G_SITOFP, G_UITOFP})
.libcallForCartesianProduct({s32, s64}, {s32});
getActionDefinitionsBuilder({G_GET_FPENV, G_SET_FPENV, G_RESET_FPENV})
.libcall();
}
// Just expand whatever loads and stores are left.
LoadStoreBuilder.lower();
if (!ST.useSoftFloat() && ST.hasVFP4Base())
getActionDefinitionsBuilder(G_FMA).legalFor({s32, s64});
else
getActionDefinitionsBuilder(G_FMA).libcallFor({s32, s64});
getActionDefinitionsBuilder({G_FREM, G_FPOW}).libcallFor({s32, s64});
if (ST.hasV5TOps()) {
getActionDefinitionsBuilder(G_CTLZ)
.legalFor({s32, s32})
.clampScalar(1, s32, s32)
.clampScalar(0, s32, s32);
getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
.lowerFor({s32, s32})
.clampScalar(1, s32, s32)
.clampScalar(0, s32, s32);
} else {
getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
.libcallFor({s32, s32})
.clampScalar(1, s32, s32)
.clampScalar(0, s32, s32);
getActionDefinitionsBuilder(G_CTLZ)
.lowerFor({s32, s32})
.clampScalar(1, s32, s32)
.clampScalar(0, s32, s32);
}
LegacyInfo.computeTables();
verify(*ST.getInstrInfo());
}
void ARMLegalizerInfo::setFCmpLibcallsAEABI() {
// FCMP_TRUE and FCMP_FALSE don't need libcalls, they should be
// default-initialized.
FCmp32Libcalls.resize(CmpInst::LAST_FCMP_PREDICATE + 1);
FCmp32Libcalls[CmpInst::FCMP_OEQ] = {
{RTLIB::OEQ_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_OGE] = {
{RTLIB::OGE_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_OGT] = {
{RTLIB::OGT_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_OLE] = {
{RTLIB::OLE_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_OLT] = {
{RTLIB::OLT_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::UO_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_ULT] = {{RTLIB::OGE_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UNE] = {{RTLIB::UNE_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UNO] = {
{RTLIB::UO_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_ONE] = {
{RTLIB::OGT_F32, CmpInst::BAD_ICMP_PREDICATE},
{RTLIB::OLT_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_UEQ] = {
{RTLIB::OEQ_F32, CmpInst::BAD_ICMP_PREDICATE},
{RTLIB::UO_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls.resize(CmpInst::LAST_FCMP_PREDICATE + 1);
FCmp64Libcalls[CmpInst::FCMP_OEQ] = {
{RTLIB::OEQ_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_OGE] = {
{RTLIB::OGE_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_OGT] = {
{RTLIB::OGT_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_OLE] = {
{RTLIB::OLE_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_OLT] = {
{RTLIB::OLT_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::UO_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_ULT] = {{RTLIB::OGE_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UNE] = {{RTLIB::UNE_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UNO] = {
{RTLIB::UO_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_ONE] = {
{RTLIB::OGT_F64, CmpInst::BAD_ICMP_PREDICATE},
{RTLIB::OLT_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_UEQ] = {
{RTLIB::OEQ_F64, CmpInst::BAD_ICMP_PREDICATE},
{RTLIB::UO_F64, CmpInst::BAD_ICMP_PREDICATE}};
}
void ARMLegalizerInfo::setFCmpLibcallsGNU() {
// FCMP_TRUE and FCMP_FALSE don't need libcalls, they should be
// default-initialized.
FCmp32Libcalls.resize(CmpInst::LAST_FCMP_PREDICATE + 1);
FCmp32Libcalls[CmpInst::FCMP_OEQ] = {{RTLIB::OEQ_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_OGE] = {{RTLIB::OGE_F32, CmpInst::ICMP_SGE}};
FCmp32Libcalls[CmpInst::FCMP_OGT] = {{RTLIB::OGT_F32, CmpInst::ICMP_SGT}};
FCmp32Libcalls[CmpInst::FCMP_OLE] = {{RTLIB::OLE_F32, CmpInst::ICMP_SLE}};
FCmp32Libcalls[CmpInst::FCMP_OLT] = {{RTLIB::OLT_F32, CmpInst::ICMP_SLT}};
FCmp32Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::UO_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F32, CmpInst::ICMP_SGE}};
FCmp32Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F32, CmpInst::ICMP_SGT}};
FCmp32Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F32, CmpInst::ICMP_SLE}};
FCmp32Libcalls[CmpInst::FCMP_ULT] = {{RTLIB::OGE_F32, CmpInst::ICMP_SLT}};
FCmp32Libcalls[CmpInst::FCMP_UNE] = {{RTLIB::UNE_F32, CmpInst::ICMP_NE}};
FCmp32Libcalls[CmpInst::FCMP_UNO] = {{RTLIB::UO_F32, CmpInst::ICMP_NE}};
FCmp32Libcalls[CmpInst::FCMP_ONE] = {{RTLIB::OGT_F32, CmpInst::ICMP_SGT},
{RTLIB::OLT_F32, CmpInst::ICMP_SLT}};
FCmp32Libcalls[CmpInst::FCMP_UEQ] = {{RTLIB::OEQ_F32, CmpInst::ICMP_EQ},
{RTLIB::UO_F32, CmpInst::ICMP_NE}};
FCmp64Libcalls.resize(CmpInst::LAST_FCMP_PREDICATE + 1);
FCmp64Libcalls[CmpInst::FCMP_OEQ] = {{RTLIB::OEQ_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_OGE] = {{RTLIB::OGE_F64, CmpInst::ICMP_SGE}};
FCmp64Libcalls[CmpInst::FCMP_OGT] = {{RTLIB::OGT_F64, CmpInst::ICMP_SGT}};
FCmp64Libcalls[CmpInst::FCMP_OLE] = {{RTLIB::OLE_F64, CmpInst::ICMP_SLE}};
FCmp64Libcalls[CmpInst::FCMP_OLT] = {{RTLIB::OLT_F64, CmpInst::ICMP_SLT}};
FCmp64Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::UO_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F64, CmpInst::ICMP_SGE}};
FCmp64Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F64, CmpInst::ICMP_SGT}};
FCmp64Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F64, CmpInst::ICMP_SLE}};
FCmp64Libcalls[CmpInst::FCMP_ULT] = {{RTLIB::OGE_F64, CmpInst::ICMP_SLT}};
FCmp64Libcalls[CmpInst::FCMP_UNE] = {{RTLIB::UNE_F64, CmpInst::ICMP_NE}};
FCmp64Libcalls[CmpInst::FCMP_UNO] = {{RTLIB::UO_F64, CmpInst::ICMP_NE}};
FCmp64Libcalls[CmpInst::FCMP_ONE] = {{RTLIB::OGT_F64, CmpInst::ICMP_SGT},
{RTLIB::OLT_F64, CmpInst::ICMP_SLT}};
FCmp64Libcalls[CmpInst::FCMP_UEQ] = {{RTLIB::OEQ_F64, CmpInst::ICMP_EQ},
{RTLIB::UO_F64, CmpInst::ICMP_NE}};
}
ARMLegalizerInfo::FCmpLibcallsList
ARMLegalizerInfo::getFCmpLibcalls(CmpInst::Predicate Predicate,
unsigned Size) const {
assert(CmpInst::isFPPredicate(Predicate) && "Unsupported FCmp predicate");
if (Size == 32)
return FCmp32Libcalls[Predicate];
if (Size == 64)
return FCmp64Libcalls[Predicate];
llvm_unreachable("Unsupported size for FCmp predicate");
}
bool ARMLegalizerInfo::legalizeCustom(LegalizerHelper &Helper, MachineInstr &MI,
LostDebugLocObserver &LocObserver) const {
using namespace TargetOpcode;
MachineIRBuilder &MIRBuilder = Helper.MIRBuilder;
MachineRegisterInfo &MRI = *MIRBuilder.getMRI();
LLVMContext &Ctx = MIRBuilder.getMF().getFunction().getContext();
switch (MI.getOpcode()) {
default:
return false;
case G_SREM:
case G_UREM: {
Register OriginalResult = MI.getOperand(0).getReg();
auto Size = MRI.getType(OriginalResult).getSizeInBits();
if (Size != 32)
return false;
auto Libcall =
MI.getOpcode() == G_SREM ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32;
// Our divmod libcalls return a struct containing the quotient and the
// remainder. Create a new, unused register for the quotient and use the
// destination of the original instruction for the remainder.
Type *ArgTy = Type::getInt32Ty(Ctx);
StructType *RetTy = StructType::get(Ctx, {ArgTy, ArgTy}, /* Packed */ true);
Register RetRegs[] = {MRI.createGenericVirtualRegister(LLT::scalar(32)),
OriginalResult};
auto Status = createLibcall(MIRBuilder, Libcall, {RetRegs, RetTy, 0},
{{MI.getOperand(1).getReg(), ArgTy, 0},
{MI.getOperand(2).getReg(), ArgTy, 0}},
LocObserver, &MI);
if (Status != LegalizerHelper::Legalized)
return false;
break;
}
case G_FCMP: {
assert(MRI.getType(MI.getOperand(2).getReg()) ==
MRI.getType(MI.getOperand(3).getReg()) &&
"Mismatched operands for G_FCMP");
auto OpSize = MRI.getType(MI.getOperand(2).getReg()).getSizeInBits();
auto OriginalResult = MI.getOperand(0).getReg();
auto Predicate =
static_cast<CmpInst::Predicate>(MI.getOperand(1).getPredicate());
auto Libcalls = getFCmpLibcalls(Predicate, OpSize);
if (Libcalls.empty()) {
assert((Predicate == CmpInst::FCMP_TRUE ||
Predicate == CmpInst::FCMP_FALSE) &&
"Predicate needs libcalls, but none specified");
MIRBuilder.buildConstant(OriginalResult,
Predicate == CmpInst::FCMP_TRUE ? 1 : 0);
MI.eraseFromParent();
return true;
}
assert((OpSize == 32 || OpSize == 64) && "Unsupported operand size");
auto *ArgTy = OpSize == 32 ? Type::getFloatTy(Ctx) : Type::getDoubleTy(Ctx);
auto *RetTy = Type::getInt32Ty(Ctx);
SmallVector<Register, 2> Results;
for (auto Libcall : Libcalls) {
auto LibcallResult = MRI.createGenericVirtualRegister(LLT::scalar(32));
auto Status = createLibcall(MIRBuilder, Libcall.LibcallID,
{LibcallResult, RetTy, 0},
{{MI.getOperand(2).getReg(), ArgTy, 0},
{MI.getOperand(3).getReg(), ArgTy, 0}},
LocObserver, &MI);
if (Status != LegalizerHelper::Legalized)
return false;
auto ProcessedResult =
Libcalls.size() == 1
? OriginalResult
: MRI.createGenericVirtualRegister(MRI.getType(OriginalResult));
// We have a result, but we need to transform it into a proper 1-bit 0 or
// 1, taking into account the different peculiarities of the values
// returned by the comparison functions.
CmpInst::Predicate ResultPred = Libcall.Predicate;
if (ResultPred == CmpInst::BAD_ICMP_PREDICATE) {
// We have a nice 0 or 1, and we just need to truncate it back to 1 bit
// to keep the types consistent.
MIRBuilder.buildTrunc(ProcessedResult, LibcallResult);
} else {
// We need to compare against 0.
assert(CmpInst::isIntPredicate(ResultPred) && "Unsupported predicate");
auto Zero = MIRBuilder.buildConstant(LLT::scalar(32), 0);
MIRBuilder.buildICmp(ResultPred, ProcessedResult, LibcallResult, Zero);
}
Results.push_back(ProcessedResult);
}
if (Results.size() != 1) {
assert(Results.size() == 2 && "Unexpected number of results");
MIRBuilder.buildOr(OriginalResult, Results[0], Results[1]);
}
break;
}
case G_FCONSTANT: {
// Convert to integer constants, while preserving the binary representation.
auto AsInteger =
MI.getOperand(1).getFPImm()->getValueAPF().bitcastToAPInt();
MIRBuilder.buildConstant(MI.getOperand(0),
*ConstantInt::get(Ctx, AsInteger));
break;
}
}
MI.eraseFromParent();
return true;
}