llvm-project/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h
Craig Topper 3f9b37ccb1 [RISCV] Remove sext_inreg+add/sub/mul/shl isel patterns.
Let the sext_inreg be selected to sext.w. Remove unneeded sext.w
during PostProcessISelDAG.

This gives opportunities for some other isel patterns to match
like the ADDIPair or matching mul with immediate to shXadd.

This becomes possible after D107658 started selecting W instructions
based on users. The sext.w will be considered a W user so isel
will often select a W instruction for the sext.w input and we can
just remove the sext.w. Otherwise we can combine the sext.w with
a ADD/SUB/MUL/SLLI to create a new W instruction in parallel
to the the original instruction.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D107708
2021-08-18 11:07:11 -07:00

200 lines
5.7 KiB
C++

//===---- RISCVISelDAGToDAG.h - A dag to dag inst selector for RISCV ------===//
//
// 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 an instruction selector for the RISCV target.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_RISCV_RISCVISELDAGTODAG_H
#define LLVM_LIB_TARGET_RISCV_RISCVISELDAGTODAG_H
#include "RISCV.h"
#include "RISCVTargetMachine.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
// RISCV-specific code to select RISCV machine instructions for
// SelectionDAG operations.
namespace llvm {
class RISCVDAGToDAGISel : public SelectionDAGISel {
const RISCVSubtarget *Subtarget = nullptr;
public:
explicit RISCVDAGToDAGISel(RISCVTargetMachine &TargetMachine)
: SelectionDAGISel(TargetMachine) {}
StringRef getPassName() const override {
return "RISCV DAG->DAG Pattern Instruction Selection";
}
bool runOnMachineFunction(MachineFunction &MF) override {
Subtarget = &MF.getSubtarget<RISCVSubtarget>();
return SelectionDAGISel::runOnMachineFunction(MF);
}
void PreprocessISelDAG() override;
void PostprocessISelDAG() override;
void Select(SDNode *Node) override;
bool SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID,
std::vector<SDValue> &OutOps) override;
bool SelectAddrFI(SDValue Addr, SDValue &Base);
bool SelectBaseAddr(SDValue Addr, SDValue &Base);
bool selectShiftMask(SDValue N, unsigned ShiftWidth, SDValue &ShAmt);
bool selectShiftMaskXLen(SDValue N, SDValue &ShAmt) {
return selectShiftMask(N, Subtarget->getXLen(), ShAmt);
}
bool selectShiftMask32(SDValue N, SDValue &ShAmt) {
return selectShiftMask(N, 32, ShAmt);
}
bool selectSExti32(SDValue N, SDValue &Val);
bool selectZExti32(SDValue N, SDValue &Val);
bool hasAllNBitUsers(SDNode *Node, unsigned Bits) const;
bool hasAllHUsers(SDNode *Node) const { return hasAllNBitUsers(Node, 16); }
bool hasAllWUsers(SDNode *Node) const { return hasAllNBitUsers(Node, 32); }
bool selectVLOp(SDValue N, SDValue &VL);
bool selectVSplat(SDValue N, SDValue &SplatVal);
bool selectVSplatSimm5(SDValue N, SDValue &SplatVal);
bool selectVSplatUimm5(SDValue N, SDValue &SplatVal);
bool selectVSplatSimm5Plus1(SDValue N, SDValue &SplatVal);
bool selectVSplatSimm5Plus1NonZero(SDValue N, SDValue &SplatVal);
bool selectRVVSimm5(SDValue N, unsigned Width, SDValue &Imm);
template <unsigned Width> bool selectRVVSimm5(SDValue N, SDValue &Imm) {
return selectRVVSimm5(N, Width, Imm);
}
void addVectorLoadStoreOperands(SDNode *Node, unsigned SEWImm,
const SDLoc &DL, unsigned CurOp,
bool IsMasked, bool IsStridedOrIndexed,
SmallVectorImpl<SDValue> &Operands,
MVT *IndexVT = nullptr);
void selectVLSEG(SDNode *Node, bool IsMasked, bool IsStrided);
void selectVLSEGFF(SDNode *Node, bool IsMasked);
void selectVLXSEG(SDNode *Node, bool IsMasked, bool IsOrdered);
void selectVSSEG(SDNode *Node, bool IsMasked, bool IsStrided);
void selectVSXSEG(SDNode *Node, bool IsMasked, bool IsOrdered);
// Return the RISC-V condition code that matches the given DAG integer
// condition code. The CondCode must be one of those supported by the RISC-V
// ISA (see translateSetCCForBranch).
static RISCVCC::CondCode getRISCVCCForIntCC(ISD::CondCode CC) {
switch (CC) {
default:
llvm_unreachable("Unsupported CondCode");
case ISD::SETEQ:
return RISCVCC::COND_EQ;
case ISD::SETNE:
return RISCVCC::COND_NE;
case ISD::SETLT:
return RISCVCC::COND_LT;
case ISD::SETGE:
return RISCVCC::COND_GE;
case ISD::SETULT:
return RISCVCC::COND_LTU;
case ISD::SETUGE:
return RISCVCC::COND_GEU;
}
}
// Include the pieces autogenerated from the target description.
#include "RISCVGenDAGISel.inc"
private:
bool doPeepholeLoadStoreADDI(SDNode *Node);
bool doPeepholeSExtW(SDNode *Node);
};
namespace RISCV {
struct VLSEGPseudo {
uint16_t NF : 4;
uint16_t Masked : 1;
uint16_t Strided : 1;
uint16_t FF : 1;
uint16_t Log2SEW : 3;
uint16_t LMUL : 3;
uint16_t Pseudo;
};
struct VLXSEGPseudo {
uint16_t NF : 4;
uint16_t Masked : 1;
uint16_t Ordered : 1;
uint16_t Log2SEW : 3;
uint16_t LMUL : 3;
uint16_t IndexLMUL : 3;
uint16_t Pseudo;
};
struct VSSEGPseudo {
uint16_t NF : 4;
uint16_t Masked : 1;
uint16_t Strided : 1;
uint16_t Log2SEW : 3;
uint16_t LMUL : 3;
uint16_t Pseudo;
};
struct VSXSEGPseudo {
uint16_t NF : 4;
uint16_t Masked : 1;
uint16_t Ordered : 1;
uint16_t Log2SEW : 3;
uint16_t LMUL : 3;
uint16_t IndexLMUL : 3;
uint16_t Pseudo;
};
struct VLEPseudo {
uint16_t Masked : 1;
uint16_t Strided : 1;
uint16_t FF : 1;
uint16_t Log2SEW : 3;
uint16_t LMUL : 3;
uint16_t Pseudo;
};
struct VSEPseudo {
uint16_t Masked :1;
uint16_t Strided : 1;
uint16_t Log2SEW : 3;
uint16_t LMUL : 3;
uint16_t Pseudo;
};
struct VLX_VSXPseudo {
uint16_t Masked : 1;
uint16_t Ordered : 1;
uint16_t Log2SEW : 3;
uint16_t LMUL : 3;
uint16_t IndexLMUL : 3;
uint16_t Pseudo;
};
#define GET_RISCVVSSEGTable_DECL
#define GET_RISCVVLSEGTable_DECL
#define GET_RISCVVLXSEGTable_DECL
#define GET_RISCVVSXSEGTable_DECL
#define GET_RISCVVLETable_DECL
#define GET_RISCVVSETable_DECL
#define GET_RISCVVLXTable_DECL
#define GET_RISCVVSXTable_DECL
#include "RISCVGenSearchableTables.inc"
} // namespace RISCV
} // namespace llvm
#endif