llvm/llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp

//===-- RISCVLegalizerInfo.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 RISC-V.
/// \todo This should be generated by TableGen.
//===----------------------------------------------------------------------===//

#include "RISCVLegalizerInfo.h"
#include "MCTargetDesc/RISCVMatInt.h"
#include "RISCVMachineFunctionInfo.h"
#include "RISCVSubtarget.h"
#include "llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h"
#include "llvm/CodeGen/GlobalISel/GenericMachineInstrs.h"
#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineMemOperand.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"

usingnamespacellvm;
usingnamespaceLegalityPredicates;
usingnamespaceLegalizeMutations;

// Is this type supported by scalar FP arithmetic operations given the current
// subtarget.
static LegalityPredicate typeIsScalarFPArith(unsigned TypeIdx,
                                             const RISCVSubtarget &ST) { … }

static LegalityPredicate
typeIsLegalIntOrFPVec(unsigned TypeIdx,
                      std::initializer_list<LLT> IntOrFPVecTys,
                      const RISCVSubtarget &ST) { … }

static LegalityPredicate
typeIsLegalBoolVec(unsigned TypeIdx, std::initializer_list<LLT> BoolVecTys,
                   const RISCVSubtarget &ST) { … }

static LegalityPredicate typeIsLegalPtrVec(unsigned TypeIdx,
                                           std::initializer_list<LLT> PtrVecTys,
                                           const RISCVSubtarget &ST) { … }

RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST)
    : … { … }

bool RISCVLegalizerInfo::legalizeIntrinsic(LegalizerHelper &Helper,
                                           MachineInstr &MI) const { … }

bool RISCVLegalizerInfo::legalizeShlAshrLshr(
    MachineInstr &MI, MachineIRBuilder &MIRBuilder,
    GISelChangeObserver &Observer) const { … }

bool RISCVLegalizerInfo::legalizeVAStart(MachineInstr &MI,
                                         MachineIRBuilder &MIRBuilder) const { … }

bool RISCVLegalizerInfo::shouldBeInConstantPool(APInt APImm,
                                                bool ShouldOptForSize) const { … }

bool RISCVLegalizerInfo::legalizeVScale(MachineInstr &MI,
                                        MachineIRBuilder &MIB) const { … }

// 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.
bool RISCVLegalizerInfo::legalizeExt(MachineInstr &MI,
                                     MachineIRBuilder &MIB) const { … }

bool RISCVLegalizerInfo::legalizeLoadStore(MachineInstr &MI,
                                           LegalizerHelper &Helper,
                                           MachineIRBuilder &MIB) const { … }

/// 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 LLT getMaskTypeFor(LLT VecTy) { … }

/// Creates an all ones mask suitable for masking a vector of type VecTy with
/// vector length VL.
static MachineInstrBuilder buildAllOnesMask(LLT VecTy, const SrcOp &VL,
                                            MachineIRBuilder &MIB,
                                            MachineRegisterInfo &MRI) { … }

/// Gets the two common "VL" operands: an all-ones mask and the vector length.
/// VecTy is a scalable vector type.
static std::pair<MachineInstrBuilder, Register>
buildDefaultVLOps(const DstOp &Dst, MachineIRBuilder &MIB,
                  MachineRegisterInfo &MRI) { … }

static MachineInstrBuilder
buildSplatPartsS64WithVL(const DstOp &Dst, const SrcOp &Passthru, Register Lo,
                         Register Hi, Register VL, MachineIRBuilder &MIB,
                         MachineRegisterInfo &MRI) { … }

static MachineInstrBuilder
buildSplatSplitS64WithVL(const DstOp &Dst, const SrcOp &Passthru,
                         const SrcOp &Scalar, Register VL,
                         MachineIRBuilder &MIB, MachineRegisterInfo &MRI) { … }

// Lower splats of s1 types to G_ICMP. For each mask vector type, we have a
// legal equivalently-sized i8 type, so we can use that as a go-between.
// Splats of s1 types that have constant value can be legalized as VMSET_VL or
// VMCLR_VL.
bool RISCVLegalizerInfo::legalizeSplatVector(MachineInstr &MI,
                                             MachineIRBuilder &MIB) const { … }

bool RISCVLegalizerInfo::legalizeCustom(
    LegalizerHelper &Helper, MachineInstr &MI,
    LostDebugLocObserver &LocObserver) const { … }