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gerrit-public.fairphone.software / toolchain / llvm-project / 2fc6b024b981830ae7d1da09a5a8b5e19ca3c6ba / . / llvm / lib / CodeGen / GlobalISel / LegalizerHelper.cpp
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//===-- llvm/CodeGen/GlobalISel/LegalizerHelper.cpp -----------------------===//
//
// 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 LegalizerHelper class to legalize
/// individual instructions and the LegalizeMachineIR wrapper pass for the
/// primary legalization.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
#include "llvm/CodeGen/GlobalISel/CallLowering.h"
#include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h"
#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#define DEBUG_TYPE "legalizer"
using namespace llvm;
using namespace LegalizeActions;
/// Try to break down \p OrigTy into \p NarrowTy sized pieces.
///
/// Returns the number of \p NarrowTy elements needed to reconstruct \p OrigTy,
/// with any leftover piece as type \p LeftoverTy
///
/// Returns -1 in the first element of the pair if the breakdown is not
/// satisfiable.
static std::pair<int, int>
getNarrowTypeBreakDown(LLT OrigTy, LLT NarrowTy, LLT &LeftoverTy) {
assert(!LeftoverTy.isValid() && "this is an out argument");
unsigned Size = OrigTy.getSizeInBits();
unsigned NarrowSize = NarrowTy.getSizeInBits();
unsigned NumParts = Size / NarrowSize;
unsigned LeftoverSize = Size - NumParts * NarrowSize;
assert(Size > NarrowSize);
if (LeftoverSize == 0)
return {NumParts, 0};
if (NarrowTy.isVector()) {
unsigned EltSize = OrigTy.getScalarSizeInBits();
if (LeftoverSize % EltSize != 0)
return {-1, -1};
LeftoverTy = LLT::scalarOrVector(LeftoverSize / EltSize, EltSize);
} else {
LeftoverTy = LLT::scalar(LeftoverSize);
}
int NumLeftover = LeftoverSize / LeftoverTy.getSizeInBits();
return std::make_pair(NumParts, NumLeftover);
}
LegalizerHelper::LegalizerHelper(MachineFunction &MF,
GISelChangeObserver &Observer,
MachineIRBuilder &Builder)
: MIRBuilder(Builder), MRI(MF.getRegInfo()),
LI(*MF.getSubtarget().getLegalizerInfo()), Observer(Observer) {
MIRBuilder.setMF(MF);
MIRBuilder.setChangeObserver(Observer);
}
LegalizerHelper::LegalizerHelper(MachineFunction &MF, const LegalizerInfo &LI,
GISelChangeObserver &Observer,
MachineIRBuilder &B)
: MIRBuilder(B), MRI(MF.getRegInfo()), LI(LI), Observer(Observer) {
MIRBuilder.setMF(MF);
MIRBuilder.setChangeObserver(Observer);
}
LegalizerHelper::LegalizeResult
LegalizerHelper::legalizeInstrStep(MachineInstr &MI) {
LLVM_DEBUG(dbgs() << "Legalizing: "; MI.print(dbgs()));
auto Step = LI.getAction(MI, MRI);
switch (Step.Action) {
case Legal:
LLVM_DEBUG(dbgs() << ".. Already legal\n");
return AlreadyLegal;
case Libcall:
LLVM_DEBUG(dbgs() << ".. Convert to libcall\n");
return libcall(MI);
case NarrowScalar:
LLVM_DEBUG(dbgs() << ".. Narrow scalar\n");
return narrowScalar(MI, Step.TypeIdx, Step.NewType);
case WidenScalar:
LLVM_DEBUG(dbgs() << ".. Widen scalar\n");
return widenScalar(MI, Step.TypeIdx, Step.NewType);
case Lower:
LLVM_DEBUG(dbgs() << ".. Lower\n");
return lower(MI, Step.TypeIdx, Step.NewType);
case FewerElements:
LLVM_DEBUG(dbgs() << ".. Reduce number of elements\n");
return fewerElementsVector(MI, Step.TypeIdx, Step.NewType);
case MoreElements:
LLVM_DEBUG(dbgs() << ".. Increase number of elements\n");
return moreElementsVector(MI, Step.TypeIdx, Step.NewType);
case Custom:
LLVM_DEBUG(dbgs() << ".. Custom legalization\n");
return LI.legalizeCustom(MI, MRI, MIRBuilder, Observer) ? Legalized
: UnableToLegalize;
default:
LLVM_DEBUG(dbgs() << ".. Unable to legalize\n");
return UnableToLegalize;
}
}
void LegalizerHelper::extractParts(unsigned Reg, LLT Ty, int NumParts,
SmallVectorImpl<unsigned> &VRegs) {
for (int i = 0; i < NumParts; ++i)
VRegs.push_back(MRI.createGenericVirtualRegister(Ty));
MIRBuilder.buildUnmerge(VRegs, Reg);
}
bool LegalizerHelper::extractParts(unsigned Reg, LLT RegTy,
LLT MainTy, LLT &LeftoverTy,
SmallVectorImpl<unsigned> &VRegs,
SmallVectorImpl<unsigned> &LeftoverRegs) {
assert(!LeftoverTy.isValid() && "this is an out argument");
unsigned RegSize = RegTy.getSizeInBits();
unsigned MainSize = MainTy.getSizeInBits();
unsigned NumParts = RegSize / MainSize;
unsigned LeftoverSize = RegSize - NumParts * MainSize;
// Use an unmerge when possible.
if (LeftoverSize == 0) {
for (unsigned I = 0; I < NumParts; ++I)
VRegs.push_back(MRI.createGenericVirtualRegister(MainTy));
MIRBuilder.buildUnmerge(VRegs, Reg);
return true;
}
if (MainTy.isVector()) {
unsigned EltSize = MainTy.getScalarSizeInBits();
if (LeftoverSize % EltSize != 0)
return false;
LeftoverTy = LLT::scalarOrVector(LeftoverSize / EltSize, EltSize);
} else {
LeftoverTy = LLT::scalar(LeftoverSize);
}
// For irregular sizes, extract the individual parts.
for (unsigned I = 0; I != NumParts; ++I) {
unsigned NewReg = MRI.createGenericVirtualRegister(MainTy);
VRegs.push_back(NewReg);
MIRBuilder.buildExtract(NewReg, Reg, MainSize * I);
}
for (unsigned Offset = MainSize * NumParts; Offset < RegSize;
Offset += LeftoverSize) {
unsigned NewReg = MRI.createGenericVirtualRegister(LeftoverTy);
LeftoverRegs.push_back(NewReg);
MIRBuilder.buildExtract(NewReg, Reg, Offset);
}
return true;
}
void LegalizerHelper::insertParts(unsigned DstReg,
LLT ResultTy, LLT PartTy,
ArrayRef<unsigned> PartRegs,
LLT LeftoverTy,
ArrayRef<unsigned> LeftoverRegs) {
if (!LeftoverTy.isValid()) {
assert(LeftoverRegs.empty());
if (!ResultTy.isVector()) {
MIRBuilder.buildMerge(DstReg, PartRegs);
return;
}
if (PartTy.isVector())
MIRBuilder.buildConcatVectors(DstReg, PartRegs);
else
MIRBuilder.buildBuildVector(DstReg, PartRegs);
return;
}
unsigned PartSize = PartTy.getSizeInBits();
unsigned LeftoverPartSize = LeftoverTy.getSizeInBits();
unsigned CurResultReg = MRI.createGenericVirtualRegister(ResultTy);
MIRBuilder.buildUndef(CurResultReg);
unsigned Offset = 0;
for (unsigned PartReg : PartRegs) {
unsigned NewResultReg = MRI.createGenericVirtualRegister(ResultTy);
MIRBuilder.buildInsert(NewResultReg, CurResultReg, PartReg, Offset);
CurResultReg = NewResultReg;
Offset += PartSize;
}
for (unsigned I = 0, E = LeftoverRegs.size(); I != E; ++I) {
// Use the original output register for the final insert to avoid a copy.
unsigned NewResultReg = (I + 1 == E) ?
DstReg : MRI.createGenericVirtualRegister(ResultTy);
MIRBuilder.buildInsert(NewResultReg, CurResultReg, LeftoverRegs[I], Offset);
CurResultReg = NewResultReg;
Offset += LeftoverPartSize;
}
}
static RTLIB::Libcall getRTLibDesc(unsigned Opcode, unsigned Size) {
switch (Opcode) {
case TargetOpcode::G_SDIV:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::SDIV_I64 : RTLIB::SDIV_I32;
case TargetOpcode::G_UDIV:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::UDIV_I64 : RTLIB::UDIV_I32;
case TargetOpcode::G_SREM:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::SREM_I64 : RTLIB::SREM_I32;
case TargetOpcode::G_UREM:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::UREM_I64 : RTLIB::UREM_I32;
case TargetOpcode::G_CTLZ_ZERO_UNDEF:
assert(Size == 32 && "Unsupported size");
return RTLIB::CTLZ_I32;
case TargetOpcode::G_FADD:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::ADD_F64 : RTLIB::ADD_F32;
case TargetOpcode::G_FSUB:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::SUB_F64 : RTLIB::SUB_F32;
case TargetOpcode::G_FMUL:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::MUL_F64 : RTLIB::MUL_F32;
case TargetOpcode::G_FDIV:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::DIV_F64 : RTLIB::DIV_F32;
case TargetOpcode::G_FEXP:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::EXP_F64 : RTLIB::EXP_F32;
case TargetOpcode::G_FEXP2:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::EXP2_F64 : RTLIB::EXP2_F32;
case TargetOpcode::G_FREM:
return Size == 64 ? RTLIB::REM_F64 : RTLIB::REM_F32;
case TargetOpcode::G_FPOW:
return Size == 64 ? RTLIB::POW_F64 : RTLIB::POW_F32;
case TargetOpcode::G_FMA:
assert((Size == 32 || Size == 64) && "Unsupported size");
return Size == 64 ? RTLIB::FMA_F64 : RTLIB::FMA_F32;
case TargetOpcode::G_FSIN:
assert((Size == 32 || Size == 64 || Size == 128) && "Unsupported size");
return Size == 128 ? RTLIB::SIN_F128
: Size == 64 ? RTLIB::SIN_F64 : RTLIB::SIN_F32;
case TargetOpcode::G_FCOS:
assert((Size == 32 || Size == 64 || Size == 128) && "Unsupported size");
return Size == 128 ? RTLIB::COS_F128
: Size == 64 ? RTLIB::COS_F64 : RTLIB::COS_F32;
case TargetOpcode::G_FLOG10:
assert((Size == 32 || Size == 64 || Size == 128) && "Unsupported size");
return Size == 128 ? RTLIB::LOG10_F128
: Size == 64 ? RTLIB::LOG10_F64 : RTLIB::LOG10_F32;
case TargetOpcode::G_FLOG:
assert((Size == 32 || Size == 64 || Size == 128) && "Unsupported size");
return Size == 128 ? RTLIB::LOG_F128
: Size == 64 ? RTLIB::LOG_F64 : RTLIB::LOG_F32;
case TargetOpcode::G_FLOG2:
assert((Size == 32 || Size == 64 || Size == 128) && "Unsupported size");
return Size == 128 ? RTLIB::LOG2_F128
: Size == 64 ? RTLIB::LOG2_F64 : RTLIB::LOG2_F32;
}
llvm_unreachable("Unknown libcall function");
}
LegalizerHelper::LegalizeResult
llvm::createLibcall(MachineIRBuilder &MIRBuilder, RTLIB::Libcall Libcall,
const CallLowering::ArgInfo &Result,
ArrayRef<CallLowering::ArgInfo> Args) {
auto &CLI = *MIRBuilder.getMF().getSubtarget().getCallLowering();
auto &TLI = *MIRBuilder.getMF().getSubtarget().getTargetLowering();
const char *Name = TLI.getLibcallName(Libcall);
MIRBuilder.getMF().getFrameInfo().setHasCalls(true);
if (!CLI.lowerCall(MIRBuilder, TLI.getLibcallCallingConv(Libcall),
MachineOperand::CreateES(Name), Result, Args))
return LegalizerHelper::UnableToLegalize;
return LegalizerHelper::Legalized;
}
// Useful for libcalls where all operands have the same type.
static LegalizerHelper::LegalizeResult
simpleLibcall(MachineInstr &MI, MachineIRBuilder &MIRBuilder, unsigned Size,
Type *OpType) {
auto Libcall = getRTLibDesc(MI.getOpcode(), Size);
SmallVector<CallLowering::ArgInfo, 3> Args;
for (unsigned i = 1; i < MI.getNumOperands(); i++)
Args.push_back({MI.getOperand(i).getReg(), OpType});
return createLibcall(MIRBuilder, Libcall, {MI.getOperand(0).getReg(), OpType},
Args);
}
static RTLIB::Libcall getConvRTLibDesc(unsigned Opcode, Type *ToType,
Type *FromType) {
auto ToMVT = MVT::getVT(ToType);
auto FromMVT = MVT::getVT(FromType);
switch (Opcode) {
case TargetOpcode::G_FPEXT:
return RTLIB::getFPEXT(FromMVT, ToMVT);
case TargetOpcode::G_FPTRUNC:
return RTLIB::getFPROUND(FromMVT, ToMVT);
case TargetOpcode::G_FPTOSI:
return RTLIB::getFPTOSINT(FromMVT, ToMVT);
case TargetOpcode::G_FPTOUI:
return RTLIB::getFPTOUINT(FromMVT, ToMVT);
case TargetOpcode::G_SITOFP:
return RTLIB::getSINTTOFP(FromMVT, ToMVT);
case TargetOpcode::G_UITOFP:
return RTLIB::getUINTTOFP(FromMVT, ToMVT);
}
llvm_unreachable("Unsupported libcall function");
}
static LegalizerHelper::LegalizeResult
conversionLibcall(MachineInstr &MI, MachineIRBuilder &MIRBuilder, Type *ToType,
Type *FromType) {
RTLIB::Libcall Libcall = getConvRTLibDesc(MI.getOpcode(), ToType, FromType);
return createLibcall(MIRBuilder, Libcall, {MI.getOperand(0).getReg(), ToType},
{{MI.getOperand(1).getReg(), FromType}});
}
LegalizerHelper::LegalizeResult
LegalizerHelper::libcall(MachineInstr &MI) {
LLT LLTy = MRI.getType(MI.getOperand(0).getReg());
unsigned Size = LLTy.getSizeInBits();
auto &Ctx = MIRBuilder.getMF().getFunction().getContext();
MIRBuilder.setInstr(MI);
switch (MI.getOpcode()) {
default:
return UnableToLegalize;
case TargetOpcode::G_SDIV:
case TargetOpcode::G_UDIV:
case TargetOpcode::G_SREM:
case TargetOpcode::G_UREM:
case TargetOpcode::G_CTLZ_ZERO_UNDEF: {
Type *HLTy = IntegerType::get(Ctx, Size);
auto Status = simpleLibcall(MI, MIRBuilder, Size, HLTy);
if (Status != Legalized)
return Status;
break;
}
case TargetOpcode::G_FADD:
case TargetOpcode::G_FSUB:
case TargetOpcode::G_FMUL:
case TargetOpcode::G_FDIV:
case TargetOpcode::G_FMA:
case TargetOpcode::G_FPOW:
case TargetOpcode::G_FREM:
case TargetOpcode::G_FCOS:
case TargetOpcode::G_FSIN:
case TargetOpcode::G_FLOG10:
case TargetOpcode::G_FLOG:
case TargetOpcode::G_FLOG2:
case TargetOpcode::G_FEXP:
case TargetOpcode::G_FEXP2: {
if (Size > 64) {
LLVM_DEBUG(dbgs() << "Size " << Size << " too large to legalize.\n");
return UnableToLegalize;
}
Type *HLTy = Size == 64 ? Type::getDoubleTy(Ctx) : Type::getFloatTy(Ctx);
auto Status = simpleLibcall(MI, MIRBuilder, Size, HLTy);
if (Status != Legalized)
return Status;
break;
}
case TargetOpcode::G_FPEXT: {
// FIXME: Support other floating point types (half, fp128 etc)
unsigned FromSize = MRI.getType(MI.getOperand(1).getReg()).getSizeInBits();
unsigned ToSize = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
if (ToSize != 64 || FromSize != 32)
return UnableToLegalize;
LegalizeResult Status = conversionLibcall(
MI, MIRBuilder, Type::getDoubleTy(Ctx), Type::getFloatTy(Ctx));
if (Status != Legalized)
return Status;
break;
}
case TargetOpcode::G_FPTRUNC: {
// FIXME: Support other floating point types (half, fp128 etc)
unsigned FromSize = MRI.getType(MI.getOperand(1).getReg()).getSizeInBits();
unsigned ToSize = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
if (ToSize != 32 || FromSize != 64)
return UnableToLegalize;
LegalizeResult Status = conversionLibcall(
MI, MIRBuilder, Type::getFloatTy(Ctx), Type::getDoubleTy(Ctx));
if (Status != Legalized)
return Status;
break;
}
case TargetOpcode::G_FPTOSI:
case TargetOpcode::G_FPTOUI: {
// FIXME: Support other types
unsigned FromSize = MRI.getType(MI.getOperand(1).getReg()).getSizeInBits();
unsigned ToSize = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
if (ToSize != 32 || (FromSize != 32 && FromSize != 64))
return UnableToLegalize;
LegalizeResult Status = conversionLibcall(
MI, MIRBuilder, Type::getInt32Ty(Ctx),
FromSize == 64 ? Type::getDoubleTy(Ctx) : Type::getFloatTy(Ctx));
if (Status != Legalized)
return Status;
break;
}
case TargetOpcode::G_SITOFP:
case TargetOpcode::G_UITOFP: {
// FIXME: Support other types
unsigned FromSize = MRI.getType(MI.getOperand(1).getReg()).getSizeInBits();
unsigned ToSize = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
if (FromSize != 32 || (ToSize != 32 && ToSize != 64))
return UnableToLegalize;
LegalizeResult Status = conversionLibcall(
MI, MIRBuilder,
ToSize == 64 ? Type::getDoubleTy(Ctx) : Type::getFloatTy(Ctx),
Type::getInt32Ty(Ctx));
if (Status != Legalized)
return Status;
break;
}
}
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult LegalizerHelper::narrowScalar(MachineInstr &MI,
unsigned TypeIdx,
LLT NarrowTy) {
MIRBuilder.setInstr(MI);
uint64_t SizeOp0 = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
uint64_t NarrowSize = NarrowTy.getSizeInBits();
switch (MI.getOpcode()) {
default:
return UnableToLegalize;
case TargetOpcode::G_IMPLICIT_DEF: {
// FIXME: add support for when SizeOp0 isn't an exact multiple of
// NarrowSize.
if (SizeOp0 % NarrowSize != 0)
return UnableToLegalize;
int NumParts = SizeOp0 / NarrowSize;
SmallVector<unsigned, 2> DstRegs;
for (int i = 0; i < NumParts; ++i)
DstRegs.push_back(
MIRBuilder.buildUndef(NarrowTy)->getOperand(0).getReg());
unsigned DstReg = MI.getOperand(0).getReg();
if(MRI.getType(DstReg).isVector())
MIRBuilder.buildBuildVector(DstReg, DstRegs);
else
MIRBuilder.buildMerge(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_CONSTANT: {
LLT Ty = MRI.getType(MI.getOperand(0).getReg());
const APInt &Val = MI.getOperand(1).getCImm()->getValue();
unsigned TotalSize = Ty.getSizeInBits();
unsigned NarrowSize = NarrowTy.getSizeInBits();
int NumParts = TotalSize / NarrowSize;
SmallVector<unsigned, 4> PartRegs;
for (int I = 0; I != NumParts; ++I) {
unsigned Offset = I * NarrowSize;
auto K = MIRBuilder.buildConstant(NarrowTy,
Val.lshr(Offset).trunc(NarrowSize));
PartRegs.push_back(K.getReg(0));
}
LLT LeftoverTy;
unsigned LeftoverBits = TotalSize - NumParts * NarrowSize;
SmallVector<unsigned, 1> LeftoverRegs;
if (LeftoverBits != 0) {
LeftoverTy = LLT::scalar(LeftoverBits);
auto K = MIRBuilder.buildConstant(
LeftoverTy,
Val.lshr(NumParts * NarrowSize).trunc(LeftoverBits));
LeftoverRegs.push_back(K.getReg(0));
}
insertParts(MI.getOperand(0).getReg(),
Ty, NarrowTy, PartRegs, LeftoverTy, LeftoverRegs);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_ADD: {
// FIXME: add support for when SizeOp0 isn't an exact multiple of
// NarrowSize.
if (SizeOp0 % NarrowSize != 0)
return UnableToLegalize;
// Expand in terms of carry-setting/consuming G_ADDE instructions.
int NumParts = SizeOp0 / NarrowTy.getSizeInBits();
SmallVector<unsigned, 2> Src1Regs, Src2Regs, DstRegs;
extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, Src1Regs);
extractParts(MI.getOperand(2).getReg(), NarrowTy, NumParts, Src2Regs);
unsigned CarryIn = MRI.createGenericVirtualRegister(LLT::scalar(1));
MIRBuilder.buildConstant(CarryIn, 0);
for (int i = 0; i < NumParts; ++i) {
unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy);
unsigned CarryOut = MRI.createGenericVirtualRegister(LLT::scalar(1));
MIRBuilder.buildUAdde(DstReg, CarryOut, Src1Regs[i],
Src2Regs[i], CarryIn);
DstRegs.push_back(DstReg);
CarryIn = CarryOut;
}
unsigned DstReg = MI.getOperand(0).getReg();
if(MRI.getType(DstReg).isVector())
MIRBuilder.buildBuildVector(DstReg, DstRegs);
else
MIRBuilder.buildMerge(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_SUB: {
// FIXME: add support for when SizeOp0 isn't an exact multiple of
// NarrowSize.
if (SizeOp0 % NarrowSize != 0)
return UnableToLegalize;
int NumParts = SizeOp0 / NarrowTy.getSizeInBits();
SmallVector<unsigned, 2> Src1Regs, Src2Regs, DstRegs;
extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, Src1Regs);
extractParts(MI.getOperand(2).getReg(), NarrowTy, NumParts, Src2Regs);
unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy);
unsigned BorrowOut = MRI.createGenericVirtualRegister(LLT::scalar(1));
MIRBuilder.buildInstr(TargetOpcode::G_USUBO, {DstReg, BorrowOut},
{Src1Regs[0], Src2Regs[0]});
DstRegs.push_back(DstReg);
unsigned BorrowIn = BorrowOut;
for (int i = 1; i < NumParts; ++i) {
DstReg = MRI.createGenericVirtualRegister(NarrowTy);
BorrowOut = MRI.createGenericVirtualRegister(LLT::scalar(1));
MIRBuilder.buildInstr(TargetOpcode::G_USUBE, {DstReg, BorrowOut},
{Src1Regs[i], Src2Regs[i], BorrowIn});
DstRegs.push_back(DstReg);
BorrowIn = BorrowOut;
}
MIRBuilder.buildMerge(MI.getOperand(0).getReg(), DstRegs);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_MUL:
case TargetOpcode::G_UMULH:
return narrowScalarMul(MI, NarrowTy);
case TargetOpcode::G_EXTRACT:
return narrowScalarExtract(MI, TypeIdx, NarrowTy);
case TargetOpcode::G_INSERT:
return narrowScalarInsert(MI, TypeIdx, NarrowTy);
case TargetOpcode::G_LOAD: {
const auto &MMO = **MI.memoperands_begin();
unsigned DstReg = MI.getOperand(0).getReg();
LLT DstTy = MRI.getType(DstReg);
if (DstTy.isVector())
return UnableToLegalize;
if (8 * MMO.getSize() != DstTy.getSizeInBits()) {
unsigned TmpReg = MRI.createGenericVirtualRegister(NarrowTy);
auto &MMO = **MI.memoperands_begin();
MIRBuilder.buildLoad(TmpReg, MI.getOperand(1).getReg(), MMO);
MIRBuilder.buildAnyExt(DstReg, TmpReg);
MI.eraseFromParent();
return Legalized;
}
return reduceLoadStoreWidth(MI, TypeIdx, NarrowTy);
}
case TargetOpcode::G_ZEXTLOAD:
case TargetOpcode::G_SEXTLOAD: {
bool ZExt = MI.getOpcode() == TargetOpcode::G_ZEXTLOAD;
unsigned DstReg = MI.getOperand(0).getReg();
unsigned PtrReg = MI.getOperand(1).getReg();
unsigned TmpReg = MRI.createGenericVirtualRegister(NarrowTy);
auto &MMO = **MI.memoperands_begin();
if (MMO.getSizeInBits() == NarrowSize) {
MIRBuilder.buildLoad(TmpReg, PtrReg, MMO);
} else {
unsigned ExtLoad = ZExt ? TargetOpcode::G_ZEXTLOAD
: TargetOpcode::G_SEXTLOAD;
MIRBuilder.buildInstr(ExtLoad)
.addDef(TmpReg)
.addUse(PtrReg)
.addMemOperand(&MMO);
}
if (ZExt)
MIRBuilder.buildZExt(DstReg, TmpReg);
else
MIRBuilder.buildSExt(DstReg, TmpReg);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_STORE: {
const auto &MMO = **MI.memoperands_begin();
unsigned SrcReg = MI.getOperand(0).getReg();
LLT SrcTy = MRI.getType(SrcReg);
if (SrcTy.isVector())
return UnableToLegalize;
int NumParts = SizeOp0 / NarrowSize;
unsigned HandledSize = NumParts * NarrowTy.getSizeInBits();
unsigned LeftoverBits = SrcTy.getSizeInBits() - HandledSize;
if (SrcTy.isVector() && LeftoverBits != 0)
return UnableToLegalize;
if (8 * MMO.getSize() != SrcTy.getSizeInBits()) {
unsigned TmpReg = MRI.createGenericVirtualRegister(NarrowTy);
auto &MMO = **MI.memoperands_begin();
MIRBuilder.buildTrunc(TmpReg, SrcReg);
MIRBuilder.buildStore(TmpReg, MI.getOperand(1).getReg(), MMO);
MI.eraseFromParent();
return Legalized;
}
return reduceLoadStoreWidth(MI, 0, NarrowTy);
}
case TargetOpcode::G_SELECT:
return narrowScalarSelect(MI, TypeIdx, NarrowTy);
case TargetOpcode::G_AND:
case TargetOpcode::G_OR:
case TargetOpcode::G_XOR: {
// Legalize bitwise operation:
// A = BinOp<Ty> B, C
// into:
// B1, ..., BN = G_UNMERGE_VALUES B
// C1, ..., CN = G_UNMERGE_VALUES C
// A1 = BinOp<Ty/N> B1, C2
// ...
// AN = BinOp<Ty/N> BN, CN
// A = G_MERGE_VALUES A1, ..., AN
return narrowScalarBasic(MI, TypeIdx, NarrowTy);
}
case TargetOpcode::G_SHL:
case TargetOpcode::G_LSHR:
case TargetOpcode::G_ASHR:
return narrowScalarShift(MI, TypeIdx, NarrowTy);
case TargetOpcode::G_CTLZ:
case TargetOpcode::G_CTLZ_ZERO_UNDEF:
case TargetOpcode::G_CTTZ:
case TargetOpcode::G_CTTZ_ZERO_UNDEF:
case TargetOpcode::G_CTPOP:
if (TypeIdx != 0)
return UnableToLegalize; // TODO
Observer.changingInstr(MI);
narrowScalarDst(MI, NarrowTy, 0, TargetOpcode::G_ZEXT);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_INTTOPTR:
if (TypeIdx != 1)
return UnableToLegalize;
Observer.changingInstr(MI);
narrowScalarSrc(MI, NarrowTy, 1);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_PTRTOINT:
if (TypeIdx != 0)
return UnableToLegalize;
Observer.changingInstr(MI);
narrowScalarDst(MI, NarrowTy, 0, TargetOpcode::G_ZEXT);
Observer.changedInstr(MI);
return Legalized;
}
}
void LegalizerHelper::widenScalarSrc(MachineInstr &MI, LLT WideTy,
unsigned OpIdx, unsigned ExtOpcode) {
MachineOperand &MO = MI.getOperand(OpIdx);
auto ExtB = MIRBuilder.buildInstr(ExtOpcode, {WideTy}, {MO.getReg()});
MO.setReg(ExtB->getOperand(0).getReg());
}
void LegalizerHelper::narrowScalarSrc(MachineInstr &MI, LLT NarrowTy,
unsigned OpIdx) {
MachineOperand &MO = MI.getOperand(OpIdx);
auto ExtB = MIRBuilder.buildInstr(TargetOpcode::G_TRUNC, {NarrowTy},
{MO.getReg()});
MO.setReg(ExtB->getOperand(0).getReg());
}
void LegalizerHelper::widenScalarDst(MachineInstr &MI, LLT WideTy,
unsigned OpIdx, unsigned TruncOpcode) {
MachineOperand &MO = MI.getOperand(OpIdx);
unsigned DstExt = MRI.createGenericVirtualRegister(WideTy);
MIRBuilder.setInsertPt(MIRBuilder.getMBB(), ++MIRBuilder.getInsertPt());
MIRBuilder.buildInstr(TruncOpcode, {MO.getReg()}, {DstExt});
MO.setReg(DstExt);
}
void LegalizerHelper::narrowScalarDst(MachineInstr &MI, LLT NarrowTy,
unsigned OpIdx, unsigned ExtOpcode) {
MachineOperand &MO = MI.getOperand(OpIdx);
unsigned DstTrunc = MRI.createGenericVirtualRegister(NarrowTy);
MIRBuilder.setInsertPt(MIRBuilder.getMBB(), ++MIRBuilder.getInsertPt());
MIRBuilder.buildInstr(ExtOpcode, {MO.getReg()}, {DstTrunc});
MO.setReg(DstTrunc);
}
void LegalizerHelper::moreElementsVectorDst(MachineInstr &MI, LLT WideTy,
unsigned OpIdx) {
MachineOperand &MO = MI.getOperand(OpIdx);
unsigned DstExt = MRI.createGenericVirtualRegister(WideTy);
MIRBuilder.setInsertPt(MIRBuilder.getMBB(), ++MIRBuilder.getInsertPt());
MIRBuilder.buildExtract(MO.getReg(), DstExt, 0);
MO.setReg(DstExt);
}
void LegalizerHelper::moreElementsVectorSrc(MachineInstr &MI, LLT MoreTy,
unsigned OpIdx) {
MachineOperand &MO = MI.getOperand(OpIdx);
LLT OldTy = MRI.getType(MO.getReg());
unsigned OldElts = OldTy.getNumElements();
unsigned NewElts = MoreTy.getNumElements();
unsigned NumParts = NewElts / OldElts;
// Use concat_vectors if the result is a multiple of the number of elements.
if (NumParts * OldElts == NewElts) {
SmallVector<unsigned, 8> Parts;
Parts.push_back(MO.getReg());
unsigned ImpDef = MIRBuilder.buildUndef(OldTy).getReg(0);
for (unsigned I = 1; I != NumParts; ++I)
Parts.push_back(ImpDef);
auto Concat = MIRBuilder.buildConcatVectors(MoreTy, Parts);
MO.setReg(Concat.getReg(0));
return;
}
unsigned MoreReg = MRI.createGenericVirtualRegister(MoreTy);
unsigned ImpDef = MIRBuilder.buildUndef(MoreTy).getReg(0);
MIRBuilder.buildInsert(MoreReg, ImpDef, MO.getReg(), 0);
MO.setReg(MoreReg);
}
LegalizerHelper::LegalizeResult
LegalizerHelper::widenScalarMergeValues(MachineInstr &MI, unsigned TypeIdx,
LLT WideTy) {
if (TypeIdx != 1)
return UnableToLegalize;
unsigned DstReg = MI.getOperand(0).getReg();
LLT DstTy = MRI.getType(DstReg);
if (!DstTy.isScalar())
return UnableToLegalize;
unsigned NumOps = MI.getNumOperands();
unsigned NumSrc = MI.getNumOperands() - 1;
unsigned PartSize = DstTy.getSizeInBits() / NumSrc;
unsigned Src1 = MI.getOperand(1).getReg();
unsigned ResultReg = MIRBuilder.buildZExt(DstTy, Src1)->getOperand(0).getReg();
for (unsigned I = 2; I != NumOps; ++I) {
const unsigned Offset = (I - 1) * PartSize;
unsigned SrcReg = MI.getOperand(I).getReg();
assert(MRI.getType(SrcReg) == LLT::scalar(PartSize));
auto ZextInput = MIRBuilder.buildZExt(DstTy, SrcReg);
unsigned NextResult = I + 1 == NumOps ? DstReg :
MRI.createGenericVirtualRegister(DstTy);
auto ShiftAmt = MIRBuilder.buildConstant(DstTy, Offset);
auto Shl = MIRBuilder.buildShl(DstTy, ZextInput, ShiftAmt);
MIRBuilder.buildOr(NextResult, ResultReg, Shl);
ResultReg = NextResult;
}
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::widenScalarUnmergeValues(MachineInstr &MI, unsigned TypeIdx,
LLT WideTy) {
if (TypeIdx != 0)
return UnableToLegalize;
unsigned NumDst = MI.getNumOperands() - 1;
unsigned SrcReg = MI.getOperand(NumDst).getReg();
LLT SrcTy = MRI.getType(SrcReg);
if (!SrcTy.isScalar())
return UnableToLegalize;
unsigned Dst0Reg = MI.getOperand(0).getReg();
LLT DstTy = MRI.getType(Dst0Reg);
if (!DstTy.isScalar())
return UnableToLegalize;
unsigned NewSrcSize = NumDst * WideTy.getSizeInBits();
LLT NewSrcTy = LLT::scalar(NewSrcSize);
unsigned SizeDiff = WideTy.getSizeInBits() - DstTy.getSizeInBits();
auto WideSrc = MIRBuilder.buildZExt(NewSrcTy, SrcReg);
for (unsigned I = 1; I != NumDst; ++I) {
auto ShiftAmt = MIRBuilder.buildConstant(NewSrcTy, SizeDiff * I);
auto Shl = MIRBuilder.buildShl(NewSrcTy, WideSrc, ShiftAmt);
WideSrc = MIRBuilder.buildOr(NewSrcTy, WideSrc, Shl);
}
Observer.changingInstr(MI);
MI.getOperand(NumDst).setReg(WideSrc->getOperand(0).getReg());
for (unsigned I = 0; I != NumDst; ++I)
widenScalarDst(MI, WideTy, I);
Observer.changedInstr(MI);
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::widenScalarExtract(MachineInstr &MI, unsigned TypeIdx,
LLT WideTy) {
unsigned DstReg = MI.getOperand(0).getReg();
unsigned SrcReg = MI.getOperand(1).getReg();
LLT SrcTy = MRI.getType(SrcReg);
LLT DstTy = MRI.getType(DstReg);
unsigned Offset = MI.getOperand(2).getImm();
if (TypeIdx == 0) {
if (SrcTy.isVector() || DstTy.isVector())
return UnableToLegalize;
SrcOp Src(SrcReg);
if (SrcTy.isPointer()) {
// Extracts from pointers can be handled only if they are really just
// simple integers.
const DataLayout &DL = MIRBuilder.getDataLayout();
if (DL.isNonIntegralAddressSpace(SrcTy.getAddressSpace()))
return UnableToLegalize;
LLT SrcAsIntTy = LLT::scalar(SrcTy.getSizeInBits());
Src = MIRBuilder.buildPtrToInt(SrcAsIntTy, Src);
SrcTy = SrcAsIntTy;
}
if (DstTy.isPointer())
return UnableToLegalize;
if (Offset == 0) {
// Avoid a shift in the degenerate case.
MIRBuilder.buildTrunc(DstReg,
MIRBuilder.buildAnyExtOrTrunc(WideTy, Src));
MI.eraseFromParent();
return Legalized;
}
// Do a shift in the source type.
LLT ShiftTy = SrcTy;
if (WideTy.getSizeInBits() > SrcTy.getSizeInBits()) {
Src = MIRBuilder.buildAnyExt(WideTy, Src);
ShiftTy = WideTy;
} else if (WideTy.getSizeInBits() > SrcTy.getSizeInBits())
return UnableToLegalize;
auto LShr = MIRBuilder.buildLShr(
ShiftTy, Src, MIRBuilder.buildConstant(ShiftTy, Offset));
MIRBuilder.buildTrunc(DstReg, LShr);
MI.eraseFromParent();
return Legalized;
}
if (SrcTy.isScalar()) {
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
Observer.changedInstr(MI);
return Legalized;
}
if (!SrcTy.isVector())
return UnableToLegalize;
if (DstTy != SrcTy.getElementType())
return UnableToLegalize;
if (Offset % SrcTy.getScalarSizeInBits() != 0)
return UnableToLegalize;
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
MI.getOperand(2).setImm((WideTy.getSizeInBits() / SrcTy.getSizeInBits()) *
Offset);
widenScalarDst(MI, WideTy.getScalarType(), 0);
Observer.changedInstr(MI);
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::widenScalarInsert(MachineInstr &MI, unsigned TypeIdx,
LLT WideTy) {
if (TypeIdx != 0)
return UnableToLegalize;
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
MIRBuilder.setInstr(MI);
switch (MI.getOpcode()) {
default:
return UnableToLegalize;
case TargetOpcode::G_EXTRACT:
return widenScalarExtract(MI, TypeIdx, WideTy);
case TargetOpcode::G_INSERT:
return widenScalarInsert(MI, TypeIdx, WideTy);
case TargetOpcode::G_MERGE_VALUES:
return widenScalarMergeValues(MI, TypeIdx, WideTy);
case TargetOpcode::G_UNMERGE_VALUES:
return widenScalarUnmergeValues(MI, TypeIdx, WideTy);
case TargetOpcode::G_UADDO:
case TargetOpcode::G_USUBO: {
if (TypeIdx == 1)
return UnableToLegalize; // TODO
auto LHSZext = MIRBuilder.buildInstr(TargetOpcode::G_ZEXT, {WideTy},
{MI.getOperand(2).getReg()});
auto RHSZext = MIRBuilder.buildInstr(TargetOpcode::G_ZEXT, {WideTy},
{MI.getOperand(3).getReg()});
unsigned Opcode = MI.getOpcode() == TargetOpcode::G_UADDO
? TargetOpcode::G_ADD
: TargetOpcode::G_SUB;
// Do the arithmetic in the larger type.
auto NewOp = MIRBuilder.buildInstr(Opcode, {WideTy}, {LHSZext, RHSZext});
LLT OrigTy = MRI.getType(MI.getOperand(0).getReg());
APInt Mask = APInt::getAllOnesValue(OrigTy.getSizeInBits());
auto AndOp = MIRBuilder.buildInstr(
TargetOpcode::G_AND, {WideTy},
{NewOp, MIRBuilder.buildConstant(WideTy, Mask.getZExtValue())});
// There is no overflow if the AndOp is the same as NewOp.
MIRBuilder.buildICmp(CmpInst::ICMP_NE, MI.getOperand(1).getReg(), NewOp,
AndOp);
// Now trunc the NewOp to the original result.
MIRBuilder.buildTrunc(MI.getOperand(0).getReg(), NewOp);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_CTTZ:
case TargetOpcode::G_CTTZ_ZERO_UNDEF:
case TargetOpcode::G_CTLZ:
case TargetOpcode::G_CTLZ_ZERO_UNDEF:
case TargetOpcode::G_CTPOP: {
if (TypeIdx == 0) {
Observer.changingInstr(MI);
widenScalarDst(MI, WideTy, 0);
Observer.changedInstr(MI);
return Legalized;
}
unsigned SrcReg = MI.getOperand(1).getReg();
// First ZEXT the input.
auto MIBSrc = MIRBuilder.buildZExt(WideTy, SrcReg);
LLT CurTy = MRI.getType(SrcReg);
if (MI.getOpcode() == TargetOpcode::G_CTTZ) {
// The count is the same in the larger type except if the original
// value was zero. This can be handled by setting the bit just off
// the top of the original type.
auto TopBit =
APInt::getOneBitSet(WideTy.getSizeInBits(), CurTy.getSizeInBits());
MIBSrc = MIRBuilder.buildOr(
WideTy, MIBSrc, MIRBuilder.buildConstant(WideTy, TopBit));
}
// Perform the operation at the larger size.
auto MIBNewOp = MIRBuilder.buildInstr(MI.getOpcode(), {WideTy}, {MIBSrc});
// This is already the correct result for CTPOP and CTTZs
if (MI.getOpcode() == TargetOpcode::G_CTLZ ||
MI.getOpcode() == TargetOpcode::G_CTLZ_ZERO_UNDEF) {
// The correct result is NewOp - (Difference in widety and current ty).
unsigned SizeDiff = WideTy.getSizeInBits() - CurTy.getSizeInBits();
MIBNewOp = MIRBuilder.buildInstr(
TargetOpcode::G_SUB, {WideTy},
{MIBNewOp, MIRBuilder.buildConstant(WideTy, SizeDiff)});
}
MIRBuilder.buildZExtOrTrunc(MI.getOperand(0), MIBNewOp);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_BSWAP: {
Observer.changingInstr(MI);
unsigned DstReg = MI.getOperand(0).getReg();
unsigned ShrReg = MRI.createGenericVirtualRegister(WideTy);
unsigned DstExt = MRI.createGenericVirtualRegister(WideTy);
unsigned ShiftAmtReg = MRI.createGenericVirtualRegister(WideTy);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
MI.getOperand(0).setReg(DstExt);
MIRBuilder.setInsertPt(MIRBuilder.getMBB(), ++MIRBuilder.getInsertPt());
LLT Ty = MRI.getType(DstReg);
unsigned DiffBits = WideTy.getScalarSizeInBits() - Ty.getScalarSizeInBits();
MIRBuilder.buildConstant(ShiftAmtReg, DiffBits);
MIRBuilder.buildInstr(TargetOpcode::G_LSHR)
.addDef(ShrReg)
.addUse(DstExt)
.addUse(ShiftAmtReg);
MIRBuilder.buildTrunc(DstReg, ShrReg);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_ADD:
case TargetOpcode::G_AND:
case TargetOpcode::G_MUL:
case TargetOpcode::G_OR:
case TargetOpcode::G_XOR:
case TargetOpcode::G_SUB:
// Perform operation at larger width (any extension is fines here, high bits
// don't affect the result) and then truncate the result back to the
// original type.
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ANYEXT);
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_SHL:
Observer.changingInstr(MI);
if (TypeIdx == 0) {
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
widenScalarDst(MI, WideTy);
} else {
assert(TypeIdx == 1);
// The "number of bits to shift" operand must preserve its value as an
// unsigned integer:
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ZEXT);
}
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_SDIV:
case TargetOpcode::G_SREM:
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_SEXT);
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_SEXT);
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_ASHR:
case TargetOpcode::G_LSHR:
Observer.changingInstr(MI);
if (TypeIdx == 0) {
unsigned CvtOp = MI.getOpcode() == TargetOpcode::G_ASHR ?
TargetOpcode::G_SEXT : TargetOpcode::G_ZEXT;
widenScalarSrc(MI, WideTy, 1, CvtOp);
widenScalarDst(MI, WideTy);
} else {
assert(TypeIdx == 1);
// The "number of bits to shift" operand must preserve its value as an
// unsigned integer:
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ZEXT);
}
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_UDIV:
case TargetOpcode::G_UREM:
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ZEXT);
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ZEXT);
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_SELECT:
Observer.changingInstr(MI);
if (TypeIdx == 0) {
// Perform operation at larger width (any extension is fine here, high
// bits don't affect the result) and then truncate the result back to the
// original type.
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ANYEXT);
widenScalarSrc(MI, WideTy, 3, TargetOpcode::G_ANYEXT);
widenScalarDst(MI, WideTy);
} else {
bool IsVec = MRI.getType(MI.getOperand(1).getReg()).isVector();
// Explicit extension is required here since high bits affect the result.
widenScalarSrc(MI, WideTy, 1, MIRBuilder.getBoolExtOp(IsVec, false));
}
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_FPTOSI:
case TargetOpcode::G_FPTOUI:
if (TypeIdx != 0)
return UnableToLegalize;
Observer.changingInstr(MI);
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_SITOFP:
if (TypeIdx != 1)
return UnableToLegalize;
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_SEXT);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_UITOFP:
if (TypeIdx != 1)
return UnableToLegalize;
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ZEXT);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_LOAD:
case TargetOpcode::G_SEXTLOAD:
case TargetOpcode::G_ZEXTLOAD:
Observer.changingInstr(MI);
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_STORE: {
if (TypeIdx != 0)
return UnableToLegalize;
LLT Ty = MRI.getType(MI.getOperand(0).getReg());
if (!isPowerOf2_32(Ty.getSizeInBits()))
return UnableToLegalize;
Observer.changingInstr(MI);
unsigned ExtType = Ty.getScalarSizeInBits() == 1 ?
TargetOpcode::G_ZEXT : TargetOpcode::G_ANYEXT;
widenScalarSrc(MI, WideTy, 0, ExtType);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_CONSTANT: {
MachineOperand &SrcMO = MI.getOperand(1);
LLVMContext &Ctx = MIRBuilder.getMF().getFunction().getContext();
const APInt &Val = SrcMO.getCImm()->getValue().sext(WideTy.getSizeInBits());
Observer.changingInstr(MI);
SrcMO.setCImm(ConstantInt::get(Ctx, Val));
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_FCONSTANT: {
MachineOperand &SrcMO = MI.getOperand(1);
LLVMContext &Ctx = MIRBuilder.getMF().getFunction().getContext();
APFloat Val = SrcMO.getFPImm()->getValueAPF();
bool LosesInfo;
switch (WideTy.getSizeInBits()) {
case 32:
Val.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven,
&LosesInfo);
break;
case 64:
Val.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven,
&LosesInfo);
break;
default:
return UnableToLegalize;
}
assert(!LosesInfo && "extend should always be lossless");
Observer.changingInstr(MI);
SrcMO.setFPImm(ConstantFP::get(Ctx, Val));
widenScalarDst(MI, WideTy, 0, TargetOpcode::G_FPTRUNC);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_IMPLICIT_DEF: {
Observer.changingInstr(MI);
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_BRCOND:
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 0, MIRBuilder.getBoolExtOp(false, false));
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_FCMP:
Observer.changingInstr(MI);
if (TypeIdx == 0)
widenScalarDst(MI, WideTy);
else {
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_FPEXT);
widenScalarSrc(MI, WideTy, 3, TargetOpcode::G_FPEXT);
}
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_ICMP:
Observer.changingInstr(MI);
if (TypeIdx == 0)
widenScalarDst(MI, WideTy);
else {
unsigned ExtOpcode = CmpInst::isSigned(static_cast<CmpInst::Predicate>(
MI.getOperand(1).getPredicate()))
? TargetOpcode::G_SEXT
: TargetOpcode::G_ZEXT;
widenScalarSrc(MI, WideTy, 2, ExtOpcode);
widenScalarSrc(MI, WideTy, 3, ExtOpcode);
}
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_GEP:
assert(TypeIdx == 1 && "unable to legalize pointer of GEP");
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_SEXT);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_PHI: {
assert(TypeIdx == 0 && "Expecting only Idx 0");
Observer.changingInstr(MI);
for (unsigned I = 1; I < MI.getNumOperands(); I += 2) {
MachineBasicBlock &OpMBB = *MI.getOperand(I + 1).getMBB();
MIRBuilder.setInsertPt(OpMBB, OpMBB.getFirstTerminator());
widenScalarSrc(MI, WideTy, I, TargetOpcode::G_ANYEXT);
}
MachineBasicBlock &MBB = *MI.getParent();
MIRBuilder.setInsertPt(MBB, --MBB.getFirstNonPHI());
widenScalarDst(MI, WideTy);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_EXTRACT_VECTOR_ELT: {
if (TypeIdx == 0) {
unsigned VecReg = MI.getOperand(1).getReg();
LLT VecTy = MRI.getType(VecReg);
Observer.changingInstr(MI);
widenScalarSrc(MI, LLT::vector(VecTy.getNumElements(),
WideTy.getSizeInBits()),
1, TargetOpcode::G_SEXT);
widenScalarDst(MI, WideTy, 0);
Observer.changedInstr(MI);
return Legalized;
}
if (TypeIdx != 2)
return UnableToLegalize;
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_SEXT);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_FADD:
case TargetOpcode::G_FMUL:
case TargetOpcode::G_FSUB:
case TargetOpcode::G_FMA:
case TargetOpcode::G_FNEG:
case TargetOpcode::G_FABS:
case TargetOpcode::G_FCANONICALIZE:
case TargetOpcode::G_FDIV:
case TargetOpcode::G_FREM:
case TargetOpcode::G_FCEIL:
case TargetOpcode::G_FFLOOR:
case TargetOpcode::G_FCOS:
case TargetOpcode::G_FSIN:
case TargetOpcode::G_FLOG10:
case TargetOpcode::G_FLOG:
case TargetOpcode::G_FLOG2:
case TargetOpcode::G_FRINT:
case TargetOpcode::G_FNEARBYINT:
case TargetOpcode::G_FSQRT:
case TargetOpcode::G_FEXP:
case TargetOpcode::G_FEXP2:
case TargetOpcode::G_FPOW:
case TargetOpcode::G_INTRINSIC_TRUNC:
case TargetOpcode::G_INTRINSIC_ROUND:
assert(TypeIdx == 0);
Observer.changingInstr(MI);
for (unsigned I = 1, E = MI.getNumOperands(); I != E; ++I)
widenScalarSrc(MI, WideTy, I, TargetOpcode::G_FPEXT);
widenScalarDst(MI, WideTy, 0, TargetOpcode::G_FPTRUNC);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_INTTOPTR:
if (TypeIdx != 1)
return UnableToLegalize;
Observer.changingInstr(MI);
widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ZEXT);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_PTRTOINT:
if (TypeIdx != 0)
return UnableToLegalize;
Observer.changingInstr(MI);
widenScalarDst(MI, WideTy, 0);
Observer.changedInstr(MI);
return Legalized;
}
}
LegalizerHelper::LegalizeResult
LegalizerHelper::lower(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
using namespace TargetOpcode;
MIRBuilder.setInstr(MI);
switch(MI.getOpcode()) {
default:
return UnableToLegalize;
case TargetOpcode::G_SREM:
case TargetOpcode::G_UREM: {
unsigned QuotReg = MRI.createGenericVirtualRegister(Ty);
MIRBuilder.buildInstr(MI.getOpcode() == G_SREM ? G_SDIV : G_UDIV)
.addDef(QuotReg)
.addUse(MI.getOperand(1).getReg())
.addUse(MI.getOperand(2).getReg());
unsigned ProdReg = MRI.createGenericVirtualRegister(Ty);
MIRBuilder.buildMul(ProdReg, QuotReg, MI.getOperand(2).getReg());
MIRBuilder.buildSub(MI.getOperand(0).getReg(), MI.getOperand(1).getReg(),
ProdReg);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_SMULO:
case TargetOpcode::G_UMULO: {
// Generate G_UMULH/G_SMULH to check for overflow and a normal G_MUL for the
// result.
unsigned Res = MI.getOperand(0).getReg();
unsigned Overflow = MI.getOperand(1).getReg();
unsigned LHS = MI.getOperand(2).getReg();
unsigned RHS = MI.getOperand(3).getReg();
MIRBuilder.buildMul(Res, LHS, RHS);
unsigned Opcode = MI.getOpcode() == TargetOpcode::G_SMULO
? TargetOpcode::G_SMULH
: TargetOpcode::G_UMULH;
unsigned HiPart = MRI.createGenericVirtualRegister(Ty);
MIRBuilder.buildInstr(Opcode)
.addDef(HiPart)
.addUse(LHS)
.addUse(RHS);
unsigned Zero = MRI.createGenericVirtualRegister(Ty);
MIRBuilder.buildConstant(Zero, 0);
// For *signed* multiply, overflow is detected by checking:
// (hi != (lo >> bitwidth-1))
if (Opcode == TargetOpcode::G_SMULH) {
unsigned Shifted = MRI.createGenericVirtualRegister(Ty);
unsigned ShiftAmt = MRI.createGenericVirtualRegister(Ty);
MIRBuilder.buildConstant(ShiftAmt, Ty.getSizeInBits() - 1);
MIRBuilder.buildInstr(TargetOpcode::G_ASHR)
.addDef(Shifted)
.addUse(Res)
.addUse(ShiftAmt);
MIRBuilder.buildICmp(CmpInst::ICMP_NE, Overflow, HiPart, Shifted);
} else {
MIRBuilder.buildICmp(CmpInst::ICMP_NE, Overflow, HiPart, Zero);
}
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_FNEG: {
// TODO: Handle vector types once we are able to
// represent them.
if (Ty.isVector())
return UnableToLegalize;
unsigned Res = MI.getOperand(0).getReg();
Type *ZeroTy;
LLVMContext &Ctx = MIRBuilder.getMF().getFunction().getContext();
switch (Ty.getSizeInBits()) {
case 16:
ZeroTy = Type::getHalfTy(Ctx);
break;
case 32:
ZeroTy = Type::getFloatTy(Ctx);
break;
case 64:
ZeroTy = Type::getDoubleTy(Ctx);
break;
case 128:
ZeroTy = Type::getFP128Ty(Ctx);
break;
default:
llvm_unreachable("unexpected floating-point type");
}
ConstantFP &ZeroForNegation =
*cast<ConstantFP>(ConstantFP::getZeroValueForNegation(ZeroTy));
auto Zero = MIRBuilder.buildFConstant(Ty, ZeroForNegation);
unsigned SubByReg = MI.getOperand(1).getReg();
unsigned ZeroReg = Zero->getOperand(0).getReg();
MachineInstr *SrcMI = MRI.getVRegDef(SubByReg);
MIRBuilder.buildInstr(TargetOpcode::G_FSUB, {Res}, {ZeroReg, SubByReg},
SrcMI->getFlags());
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_FSUB: {
// Lower (G_FSUB LHS, RHS) to (G_FADD LHS, (G_FNEG RHS)).
// First, check if G_FNEG is marked as Lower. If so, we may
// end up with an infinite loop as G_FSUB is used to legalize G_FNEG.
if (LI.getAction({G_FNEG, {Ty}}).Action == Lower)
return UnableToLegalize;
unsigned Res = MI.getOperand(0).getReg();
unsigned LHS = MI.getOperand(1).getReg();
unsigned RHS = MI.getOperand(2).getReg();
unsigned Neg = MRI.createGenericVirtualRegister(Ty);
MIRBuilder.buildInstr(TargetOpcode::G_FNEG).addDef(Neg).addUse(RHS);
MIRBuilder.buildInstr(TargetOpcode::G_FADD, {Res}, {LHS, Neg}, MI.getFlags());
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_ATOMIC_CMPXCHG_WITH_SUCCESS: {
unsigned OldValRes = MI.getOperand(0).getReg();
unsigned SuccessRes = MI.getOperand(1).getReg();
unsigned Addr = MI.getOperand(2).getReg();
unsigned CmpVal = MI.getOperand(3).getReg();
unsigned NewVal = MI.getOperand(4).getReg();
MIRBuilder.buildAtomicCmpXchg(OldValRes, Addr, CmpVal, NewVal,
**MI.memoperands_begin());
MIRBuilder.buildICmp(CmpInst::ICMP_EQ, SuccessRes, OldValRes, CmpVal);
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_LOAD:
case TargetOpcode::G_SEXTLOAD:
case TargetOpcode::G_ZEXTLOAD: {
// Lower to a memory-width G_LOAD and a G_SEXT/G_ZEXT/G_ANYEXT
unsigned DstReg = MI.getOperand(0).getReg();
unsigned PtrReg = MI.getOperand(1).getReg();
LLT DstTy = MRI.getType(DstReg);
auto &MMO = **MI.memoperands_begin();
if (DstTy.getSizeInBits() == MMO.getSize() /* in bytes */ * 8) {
// In the case of G_LOAD, this was a non-extending load already and we're
// about to lower to the same instruction.
if (MI.getOpcode() == TargetOpcode::G_LOAD)
return UnableToLegalize;
MIRBuilder.buildLoad(DstReg, PtrReg, MMO);
MI.eraseFromParent();
return Legalized;
}
if (DstTy.isScalar()) {
unsigned TmpReg =
MRI.createGenericVirtualRegister(LLT::scalar(MMO.getSizeInBits()));
MIRBuilder.buildLoad(TmpReg, PtrReg, MMO);
switch (MI.getOpcode()) {
default:
llvm_unreachable("Unexpected opcode");
case TargetOpcode::G_LOAD:
MIRBuilder.buildAnyExt(DstReg, TmpReg);
break;
case TargetOpcode::G_SEXTLOAD:
MIRBuilder.buildSExt(DstReg, TmpReg);
break;
case TargetOpcode::G_ZEXTLOAD:
MIRBuilder.buildZExt(DstReg, TmpReg);
break;
}
MI.eraseFromParent();
return Legalized;
}
return UnableToLegalize;
}
case TargetOpcode::G_CTLZ_ZERO_UNDEF:
case TargetOpcode::G_CTTZ_ZERO_UNDEF:
case TargetOpcode::G_CTLZ:
case TargetOpcode::G_CTTZ:
case TargetOpcode::G_CTPOP:
return lowerBitCount(MI, TypeIdx, Ty);
case G_UADDO: {
unsigned Res = MI.getOperand(0).getReg();
unsigned CarryOut = MI.getOperand(1).getReg();
unsigned LHS = MI.getOperand(2).getReg();
unsigned RHS = MI.getOperand(3).getReg();
MIRBuilder.buildAdd(Res, LHS, RHS);
MIRBuilder.buildICmp(CmpInst::ICMP_ULT, CarryOut, Res, RHS);
MI.eraseFromParent();
return Legalized;
}
case G_UADDE: {
unsigned Res = MI.getOperand(0).getReg();
unsigned CarryOut = MI.getOperand(1).getReg();
unsigned LHS = MI.getOperand(2).getReg();
unsigned RHS = MI.getOperand(3).getReg();
unsigned CarryIn = MI.getOperand(4).getReg();
unsigned TmpRes = MRI.createGenericVirtualRegister(Ty);
unsigned ZExtCarryIn = MRI.createGenericVirtualRegister(Ty);
MIRBuilder.buildAdd(TmpRes, LHS, RHS);
MIRBuilder.buildZExt(ZExtCarryIn, CarryIn);
MIRBuilder.buildAdd(Res, TmpRes, ZExtCarryIn);
MIRBuilder.buildICmp(CmpInst::ICMP_ULT, CarryOut, Res, LHS);
MI.eraseFromParent();
return Legalized;
}
case G_USUBO: {
unsigned Res = MI.getOperand(0).getReg();
unsigned BorrowOut = MI.getOperand(1).getReg();
unsigned LHS = MI.getOperand(2).getReg();
unsigned RHS = MI.getOperand(3).getReg();
MIRBuilder.buildSub(Res, LHS, RHS);
MIRBuilder.buildICmp(CmpInst::ICMP_ULT, BorrowOut, LHS, RHS);
MI.eraseFromParent();
return Legalized;
}
case G_USUBE: {
unsigned Res = MI.getOperand(0).getReg();
unsigned BorrowOut = MI.getOperand(1).getReg();
unsigned LHS = MI.getOperand(2).getReg();
unsigned RHS = MI.getOperand(3).getReg();
unsigned BorrowIn = MI.getOperand(4).getReg();
unsigned TmpRes = MRI.createGenericVirtualRegister(Ty);
unsigned ZExtBorrowIn = MRI.createGenericVirtualRegister(Ty);
unsigned LHS_EQ_RHS = MRI.createGenericVirtualRegister(LLT::scalar(1));
unsigned LHS_ULT_RHS = MRI.createGenericVirtualRegister(LLT::scalar(1));
MIRBuilder.buildSub(TmpRes, LHS, RHS);
MIRBuilder.buildZExt(ZExtBorrowIn, BorrowIn);
MIRBuilder.buildSub(Res, TmpRes, ZExtBorrowIn);
MIRBuilder.buildICmp(CmpInst::ICMP_EQ, LHS_EQ_RHS, LHS, RHS);
MIRBuilder.buildICmp(CmpInst::ICMP_ULT, LHS_ULT_RHS, LHS, RHS);
MIRBuilder.buildSelect(BorrowOut, LHS_EQ_RHS, BorrowIn, LHS_ULT_RHS);
MI.eraseFromParent();
return Legalized;
}
}
}
LegalizerHelper::LegalizeResult LegalizerHelper::fewerElementsVectorImplicitDef(
MachineInstr &MI, unsigned TypeIdx, LLT NarrowTy) {
SmallVector<unsigned, 2> DstRegs;
unsigned NarrowSize = NarrowTy.getSizeInBits();
unsigned DstReg = MI.getOperand(0).getReg();
unsigned Size = MRI.getType(DstReg).getSizeInBits();
int NumParts = Size / NarrowSize;
// FIXME: Don't know how to handle the situation where the small vectors
// aren't all the same size yet.
if (Size % NarrowSize != 0)
return UnableToLegalize;
for (int i = 0; i < NumParts; ++i) {
unsigned TmpReg = MRI.createGenericVirtualRegister(NarrowTy);
MIRBuilder.buildUndef(TmpReg);
DstRegs.push_back(TmpReg);
}
if (NarrowTy.isVector())
MIRBuilder.buildConcatVectors(DstReg, DstRegs);
else
MIRBuilder.buildBuildVector(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::fewerElementsVectorBasic(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
const unsigned Opc = MI.getOpcode();
const unsigned NumOps = MI.getNumOperands() - 1;
const unsigned NarrowSize = NarrowTy.getSizeInBits();
const unsigned DstReg = MI.getOperand(0).getReg();
const unsigned Flags = MI.getFlags();
const LLT DstTy = MRI.getType(DstReg);
const unsigned Size = DstTy.getSizeInBits();
const int NumParts = Size / NarrowSize;
const LLT EltTy = DstTy.getElementType();
const unsigned EltSize = EltTy.getSizeInBits();
const unsigned BitsForNumParts = NarrowSize * NumParts;
// Check if we have any leftovers. If we do, then only handle the case where
// the leftover is one element.
if (BitsForNumParts != Size && BitsForNumParts + EltSize != Size)
return UnableToLegalize;
if (BitsForNumParts != Size) {
unsigned AccumDstReg = MRI.createGenericVirtualRegister(DstTy);
MIRBuilder.buildUndef(AccumDstReg);
// Handle the pieces which evenly divide into the requested type with
// extract/op/insert sequence.
for (unsigned Offset = 0; Offset < BitsForNumParts; Offset += NarrowSize) {
SmallVector<SrcOp, 4> SrcOps;
for (unsigned I = 1, E = MI.getNumOperands(); I != E; ++I) {
unsigned PartOpReg = MRI.createGenericVirtualRegister(NarrowTy);
MIRBuilder.buildExtract(PartOpReg, MI.getOperand(I).getReg(), Offset);
SrcOps.push_back(PartOpReg);
}
unsigned PartDstReg = MRI.createGenericVirtualRegister(NarrowTy);
MIRBuilder.buildInstr(Opc, {PartDstReg}, SrcOps, Flags);
unsigned PartInsertReg = MRI.createGenericVirtualRegister(DstTy);
MIRBuilder.buildInsert(PartInsertReg, AccumDstReg, PartDstReg, Offset);
AccumDstReg = PartInsertReg;
}
// Handle the remaining element sized leftover piece.
SmallVector<SrcOp, 4> SrcOps;
for (unsigned I = 1, E = MI.getNumOperands(); I != E; ++I) {
unsigned PartOpReg = MRI.createGenericVirtualRegister(EltTy);
MIRBuilder.buildExtract(PartOpReg, MI.getOperand(I).getReg(),
BitsForNumParts);
SrcOps.push_back(PartOpReg);
}
unsigned PartDstReg = MRI.createGenericVirtualRegister(EltTy);
MIRBuilder.buildInstr(Opc, {PartDstReg}, SrcOps, Flags);
MIRBuilder.buildInsert(DstReg, AccumDstReg, PartDstReg, BitsForNumParts);
MI.eraseFromParent();
return Legalized;
}
SmallVector<unsigned, 2> DstRegs, Src0Regs, Src1Regs, Src2Regs;
extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, Src0Regs);
if (NumOps >= 2)
extractParts(MI.getOperand(2).getReg(), NarrowTy, NumParts, Src1Regs);
if (NumOps >= 3)
extractParts(MI.getOperand(3).getReg(), NarrowTy, NumParts, Src2Regs);
for (int i = 0; i < NumParts; ++i) {
unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy);
if (NumOps == 1)
MIRBuilder.buildInstr(Opc, {DstReg}, {Src0Regs[i]}, Flags);
else if (NumOps == 2) {
MIRBuilder.buildInstr(Opc, {DstReg}, {Src0Regs[i], Src1Regs[i]}, Flags);
} else if (NumOps == 3) {
MIRBuilder.buildInstr(Opc, {DstReg},
{Src0Regs[i], Src1Regs[i], Src2Regs[i]}, Flags);
}
DstRegs.push_back(DstReg);
}
if (NarrowTy.isVector())
MIRBuilder.buildConcatVectors(DstReg, DstRegs);
else
MIRBuilder.buildBuildVector(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
// Handle splitting vector operations which need to have the same number of
// elements in each type index, but each type index may have a different element
// type.
//
// e.g. <4 x s64> = G_SHL <4 x s64>, <4 x s32> ->
// <2 x s64> = G_SHL <2 x s64>, <2 x s32>
// <2 x s64> = G_SHL <2 x s64>, <2 x s32>
//
// Also handles some irregular breakdown cases, e.g.
// e.g. <3 x s64> = G_SHL <3 x s64>, <3 x s32> ->
// <2 x s64> = G_SHL <2 x s64>, <2 x s32>
// s64 = G_SHL s64, s32
LegalizerHelper::LegalizeResult
LegalizerHelper::fewerElementsVectorMultiEltType(
MachineInstr &MI, unsigned TypeIdx, LLT NarrowTyArg) {
if (TypeIdx != 0)
return UnableToLegalize;
const LLT NarrowTy0 = NarrowTyArg;
const unsigned NewNumElts =
NarrowTy0.isVector() ? NarrowTy0.getNumElements() : 1;
const unsigned DstReg = MI.getOperand(0).getReg();
LLT DstTy = MRI.getType(DstReg);
LLT LeftoverTy0;
int NumParts, NumLeftover;
// All of the operands need to have the same number of elements, so if we can
// determine a type breakdown for the result type, we can for all of the
// source types.
std::tie(NumParts, NumLeftover)
= getNarrowTypeBreakDown(DstTy, NarrowTy0, LeftoverTy0);
if (NumParts < 0)
return UnableToLegalize;
SmallVector<MachineInstrBuilder, 4> NewInsts;
SmallVector<unsigned, 4> DstRegs, LeftoverDstRegs;
SmallVector<unsigned, 4> PartRegs, LeftoverRegs;
for (unsigned I = 1, E = MI.getNumOperands(); I != E; ++I) {
LLT LeftoverTy;
unsigned SrcReg = MI.getOperand(I).getReg();
LLT SrcTyI = MRI.getType(SrcReg);
LLT NarrowTyI = LLT::scalarOrVector(NewNumElts, SrcTyI.getScalarType());
LLT LeftoverTyI;
// Split this operand into the requested typed registers, and any leftover
// required to reproduce the original type.
if (!extractParts(SrcReg, SrcTyI, NarrowTyI, LeftoverTyI, PartRegs,
LeftoverRegs))
return UnableToLegalize;
if (I == 1) {
// For the first operand, create an instruction for each part and setup
// the result.
for (unsigned PartReg : PartRegs) {
unsigned PartDstReg = MRI.createGenericVirtualRegister(NarrowTy0);
NewInsts.push_back(MIRBuilder.buildInstrNoInsert(MI.getOpcode())
.addDef(PartDstReg)
.addUse(PartReg));
DstRegs.push_back(PartDstReg);
}
for (unsigned LeftoverReg : LeftoverRegs) {
unsigned PartDstReg = MRI.createGenericVirtualRegister(LeftoverTy0);
NewInsts.push_back(MIRBuilder.buildInstrNoInsert(MI.getOpcode())
.addDef(PartDstReg)
.addUse(LeftoverReg));
LeftoverDstRegs.push_back(PartDstReg);
}
} else {
assert(NewInsts.size() == PartRegs.size() + LeftoverRegs.size());
// Add the newly created operand splits to the existing instructions. The
// odd-sized pieces are ordered after the requested NarrowTyArg sized
// pieces.
unsigned InstCount = 0;
for (unsigned J = 0, JE = PartRegs.size(); J != JE; ++J)
NewInsts[InstCount++].addUse(PartRegs[J]);
for (unsigned J = 0, JE = LeftoverRegs.size(); J != JE; ++J)
NewInsts[InstCount++].addUse(LeftoverRegs[J]);
}
PartRegs.clear();
LeftoverRegs.clear();
}
// Insert the newly built operations and rebuild the result register.
for (auto &MIB : NewInsts)
MIRBuilder.insertInstr(MIB);
insertParts(DstReg, DstTy, NarrowTy0, DstRegs, LeftoverTy0, LeftoverDstRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::fewerElementsVectorCasts(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
if (TypeIdx != 0)
return UnableToLegalize;
unsigned DstReg = MI.getOperand(0).getReg();
unsigned SrcReg = MI.getOperand(1).getReg();
LLT DstTy = MRI.getType(DstReg);
LLT SrcTy = MRI.getType(SrcReg);
LLT NarrowTy0 = NarrowTy;
LLT NarrowTy1;
unsigned NumParts;
if (NarrowTy.isVector()) {
// Uneven breakdown not handled.
NumParts = DstTy.getNumElements() / NarrowTy.getNumElements();
if (NumParts * NarrowTy.getNumElements() != DstTy.getNumElements())
return UnableToLegalize;
NarrowTy1 = LLT::vector(NumParts, SrcTy.getElementType().getSizeInBits());
} else {
NumParts = DstTy.getNumElements();
NarrowTy1 = SrcTy.getElementType();
}
SmallVector<unsigned, 4> SrcRegs, DstRegs;
extractParts(SrcReg, NarrowTy1, NumParts, SrcRegs);
for (unsigned I = 0; I < NumParts; ++I) {
unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy0);
MachineInstr *NewInst = MIRBuilder.buildInstr(MI.getOpcode())
.addDef(DstReg)
.addUse(SrcRegs[I]);
NewInst->setFlags(MI.getFlags());
DstRegs.push_back(DstReg);
}
if (NarrowTy.isVector())
MIRBuilder.buildConcatVectors(DstReg, DstRegs);
else
MIRBuilder.buildBuildVector(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::fewerElementsVectorCmp(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
unsigned DstReg = MI.getOperand(0).getReg();
unsigned Src0Reg = MI.getOperand(2).getReg();
LLT DstTy = MRI.getType(DstReg);
LLT SrcTy = MRI.getType(Src0Reg);
unsigned NumParts;
LLT NarrowTy0, NarrowTy1;
if (TypeIdx == 0) {
unsigned NewElts = NarrowTy.isVector() ? NarrowTy.getNumElements() : 1;
unsigned OldElts = DstTy.getNumElements();
NarrowTy0 = NarrowTy;
NumParts = NarrowTy.isVector() ? (OldElts / NewElts) : DstTy.getNumElements();
NarrowTy1 = NarrowTy.isVector() ?
LLT::vector(NarrowTy.getNumElements(), SrcTy.getScalarSizeInBits()) :
SrcTy.getElementType();
} else {
unsigned NewElts = NarrowTy.isVector() ? NarrowTy.getNumElements() : 1;
unsigned OldElts = SrcTy.getNumElements();
NumParts = NarrowTy.isVector() ? (OldElts / NewElts) :
NarrowTy.getNumElements();
NarrowTy0 = LLT::vector(NarrowTy.getNumElements(),
DstTy.getScalarSizeInBits());
NarrowTy1 = NarrowTy;
}
// FIXME: Don't know how to handle the situation where the small vectors
// aren't all the same size yet.
if (NarrowTy1.isVector() &&
NarrowTy1.getNumElements() * NumParts != DstTy.getNumElements())
return UnableToLegalize;
CmpInst::Predicate Pred
= static_cast<CmpInst::Predicate>(MI.getOperand(1).getPredicate());
SmallVector<unsigned, 2> Src1Regs, Src2Regs, DstRegs;
extractParts(MI.getOperand(2).getReg(), NarrowTy1, NumParts, Src1Regs);
extractParts(MI.getOperand(3).getReg(), NarrowTy1, NumParts, Src2Regs);
for (unsigned I = 0; I < NumParts; ++I) {
unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy0);
DstRegs.push_back(DstReg);
if (MI.getOpcode() == TargetOpcode::G_ICMP)
MIRBuilder.buildICmp(Pred, DstReg, Src1Regs[I], Src2Regs[I]);
else {
MachineInstr *NewCmp
= MIRBuilder.buildFCmp(Pred, DstReg, Src1Regs[I], Src2Regs[I]);
NewCmp->setFlags(MI.getFlags());
}
}
if (NarrowTy1.isVector())
MIRBuilder.buildConcatVectors(DstReg, DstRegs);
else
MIRBuilder.buildBuildVector(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::fewerElementsVectorSelect(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
unsigned DstReg = MI.getOperand(0).getReg();
unsigned CondReg = MI.getOperand(1).getReg();
unsigned NumParts = 0;
LLT NarrowTy0, NarrowTy1;
LLT DstTy = MRI.getType(DstReg);
LLT CondTy = MRI.getType(CondReg);
unsigned Size = DstTy.getSizeInBits();
assert(TypeIdx == 0 || CondTy.isVector());
if (TypeIdx == 0) {
NarrowTy0 = NarrowTy;
NarrowTy1 = CondTy;
unsigned NarrowSize = NarrowTy0.getSizeInBits();
// FIXME: Don't know how to handle the situation where the small vectors
// aren't all the same size yet.
if (Size % NarrowSize != 0)
return UnableToLegalize;
NumParts = Size / NarrowSize;
// Need to break down the condition type
if (CondTy.isVector()) {
if (CondTy.getNumElements() == NumParts)
NarrowTy1 = CondTy.getElementType();
else
NarrowTy1 = LLT::vector(CondTy.getNumElements() / NumParts,
CondTy.getScalarSizeInBits());
}
} else {
NumParts = CondTy.getNumElements();
if (NarrowTy.isVector()) {
// TODO: Handle uneven breakdown.
if (NumParts * NarrowTy.getNumElements() != CondTy.getNumElements())
return UnableToLegalize;
return UnableToLegalize;
} else {
NarrowTy0 = DstTy.getElementType();
NarrowTy1 = NarrowTy;
}
}
SmallVector<unsigned, 2> DstRegs, Src0Regs, Src1Regs, Src2Regs;
if (CondTy.isVector())
extractParts(MI.getOperand(1).getReg(), NarrowTy1, NumParts, Src0Regs);
extractParts(MI.getOperand(2).getReg(), NarrowTy0, NumParts, Src1Regs);
extractParts(MI.getOperand(3).getReg(), NarrowTy0, NumParts, Src2Regs);
for (unsigned i = 0; i < NumParts; ++i) {
unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy0);
MIRBuilder.buildSelect(DstReg, CondTy.isVector() ? Src0Regs[i] : CondReg,
Src1Regs[i], Src2Regs[i]);
DstRegs.push_back(DstReg);
}
if (NarrowTy0.isVector())
MIRBuilder.buildConcatVectors(DstReg, DstRegs);
else
MIRBuilder.buildBuildVector(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::fewerElementsVectorPhi(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
const unsigned DstReg = MI.getOperand(0).getReg();
LLT PhiTy = MRI.getType(DstReg);
LLT LeftoverTy;
// All of the operands need to have the same number of elements, so if we can
// determine a type breakdown for the result type, we can for all of the
// source types.
int NumParts, NumLeftover;
std::tie(NumParts, NumLeftover)
= getNarrowTypeBreakDown(PhiTy, NarrowTy, LeftoverTy);
if (NumParts < 0)
return UnableToLegalize;
SmallVector<unsigned, 4> DstRegs, LeftoverDstRegs;
SmallVector<MachineInstrBuilder, 4> NewInsts;
const int TotalNumParts = NumParts + NumLeftover;
// Insert the new phis in the result block first.
for (int I = 0; I != TotalNumParts; ++I) {
LLT Ty = I < NumParts ? NarrowTy : LeftoverTy;
unsigned PartDstReg = MRI.createGenericVirtualRegister(Ty);
NewInsts.push_back(MIRBuilder.buildInstr(TargetOpcode::G_PHI)
.addDef(PartDstReg));
if (I < NumParts)
DstRegs.push_back(PartDstReg);
else
LeftoverDstRegs.push_back(PartDstReg);
}
MachineBasicBlock *MBB = MI.getParent();
MIRBuilder.setInsertPt(*MBB, MBB->getFirstNonPHI());
insertParts(DstReg, PhiTy, NarrowTy, DstRegs, LeftoverTy, LeftoverDstRegs);
SmallVector<unsigned, 4> PartRegs, LeftoverRegs;
// Insert code to extract the incoming values in each predecessor block.
for (unsigned I = 1, E = MI.getNumOperands(); I != E; I += 2) {
PartRegs.clear();
LeftoverRegs.clear();
unsigned SrcReg = MI.getOperand(I).getReg();
MachineBasicBlock &OpMBB = *MI.getOperand(I + 1).getMBB();
MIRBuilder.setInsertPt(OpMBB, OpMBB.getFirstTerminator());
LLT Unused;
if (!extractParts(SrcReg, PhiTy, NarrowTy, Unused, PartRegs,
LeftoverRegs))
return UnableToLegalize;
// Add the newly created operand splits to the existing instructions. The
// odd-sized pieces are ordered after the requested NarrowTyArg sized
// pieces.
for (int J = 0; J != TotalNumParts; ++J) {
MachineInstrBuilder MIB = NewInsts[J];
MIB.addUse(J < NumParts ? PartRegs[J] : LeftoverRegs[J - NumParts]);
MIB.addMBB(&OpMBB);
}
}
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::reduceLoadStoreWidth(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
// FIXME: Don't know how to handle secondary types yet.
if (TypeIdx != 0)
return UnableToLegalize;
MachineMemOperand *MMO = *MI.memoperands_begin();
// This implementation doesn't work for atomics. Give up instead of doing
// something invalid.
if (MMO->getOrdering() != AtomicOrdering::NotAtomic ||
MMO->getFailureOrdering() != AtomicOrdering::NotAtomic)
return UnableToLegalize;
bool IsLoad = MI.getOpcode() == TargetOpcode::G_LOAD;
unsigned ValReg = MI.getOperand(0).getReg();
unsigned AddrReg = MI.getOperand(1).getReg();
LLT ValTy = MRI.getType(ValReg);
int NumParts = -1;
int NumLeftover = -1;
LLT LeftoverTy;
SmallVector<unsigned, 8> NarrowRegs, NarrowLeftoverRegs;
if (IsLoad) {
std::tie(NumParts, NumLeftover) = getNarrowTypeBreakDown(ValTy, NarrowTy, LeftoverTy);
} else {
if (extractParts(ValReg, ValTy, NarrowTy, LeftoverTy, NarrowRegs,
NarrowLeftoverRegs)) {
NumParts = NarrowRegs.size();
NumLeftover = NarrowLeftoverRegs.size();
}
}
if (NumParts == -1)
return UnableToLegalize;
const LLT OffsetTy = LLT::scalar(MRI.getType(AddrReg).getScalarSizeInBits());
unsigned TotalSize = ValTy.getSizeInBits();
// Split the load/store into PartTy sized pieces starting at Offset. If this
// is a load, return the new registers in ValRegs. For a store, each elements
// of ValRegs should be PartTy. Returns the next offset that needs to be
// handled.
auto splitTypePieces = [=](LLT PartTy, SmallVectorImpl<unsigned> &ValRegs,
unsigned Offset) -> unsigned {
MachineFunction &MF = MIRBuilder.getMF();
unsigned PartSize = PartTy.getSizeInBits();
for (unsigned Idx = 0, E = NumParts; Idx != E && Offset < TotalSize;
Offset += PartSize, ++Idx) {
unsigned ByteSize = PartSize / 8;
unsigned ByteOffset = Offset / 8;
unsigned NewAddrReg = 0;
MIRBuilder.materializeGEP(NewAddrReg, AddrReg, OffsetTy, ByteOffset);
MachineMemOperand *NewMMO =
MF.getMachineMemOperand(MMO, ByteOffset, ByteSize);
if (IsLoad) {
unsigned Dst = MRI.createGenericVirtualRegister(PartTy);
ValRegs.push_back(Dst);
MIRBuilder.buildLoad(Dst, NewAddrReg, *NewMMO);
} else {
MIRBuilder.buildStore(ValRegs[Idx], NewAddrReg, *NewMMO);
}
}
return Offset;
};
unsigned HandledOffset = splitTypePieces(NarrowTy, NarrowRegs, 0);
// Handle the rest of the register if this isn't an even type breakdown.
if (LeftoverTy.isValid())
splitTypePieces(LeftoverTy, NarrowLeftoverRegs, HandledOffset);
if (IsLoad) {
insertParts(ValReg, ValTy, NarrowTy, NarrowRegs,
LeftoverTy, NarrowLeftoverRegs);
}
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::fewerElementsVector(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
using namespace TargetOpcode;
MIRBuilder.setInstr(MI);
switch (MI.getOpcode()) {
case G_IMPLICIT_DEF:
return fewerElementsVectorImplicitDef(MI, TypeIdx, NarrowTy);
case G_AND:
case G_OR:
case G_XOR:
case G_ADD:
case G_SUB:
case G_MUL:
case G_SMULH:
case G_UMULH:
case G_FADD:
case G_FMUL:
case G_FSUB:
case G_FNEG:
case G_FABS:
case G_FCANONICALIZE:
case G_FDIV:
case G_FREM:
case G_FMA:
case G_FPOW:
case G_FEXP:
case G_FEXP2:
case G_FLOG:
case G_FLOG2:
case G_FLOG10:
case G_FNEARBYINT:
case G_FCEIL:
case G_FFLOOR:
case G_FRINT:
case G_INTRINSIC_ROUND:
case G_INTRINSIC_TRUNC:
case G_FCOS:
case G_FSIN:
case G_FSQRT:
case G_BSWAP:
case G_SDIV:
return fewerElementsVectorBasic(MI, TypeIdx, NarrowTy);
case G_SHL:
case G_LSHR:
case G_ASHR:
case G_CTLZ:
case G_CTLZ_ZERO_UNDEF:
case G_CTTZ:
case G_CTTZ_ZERO_UNDEF:
case G_CTPOP:
case G_FCOPYSIGN:
return fewerElementsVectorMultiEltType(MI, TypeIdx, NarrowTy);
case G_ZEXT:
case G_SEXT:
case G_ANYEXT:
case G_FPEXT:
case G_FPTRUNC:
case G_SITOFP:
case G_UITOFP:
case G_FPTOSI:
case G_FPTOUI:
case G_INTTOPTR:
case G_PTRTOINT:
case G_ADDRSPACE_CAST:
return fewerElementsVectorCasts(MI, TypeIdx, NarrowTy);
case G_ICMP:
case G_FCMP:
return fewerElementsVectorCmp(MI, TypeIdx, NarrowTy);
case G_SELECT:
return fewerElementsVectorSelect(MI, TypeIdx, NarrowTy);
case G_PHI:
return fewerElementsVectorPhi(MI, TypeIdx, NarrowTy);
case G_LOAD:
case G_STORE:
return reduceLoadStoreWidth(MI, TypeIdx, NarrowTy);
default:
return UnableToLegalize;
}
}
LegalizerHelper::LegalizeResult
LegalizerHelper::narrowScalarShiftByConstant(MachineInstr &MI, const APInt &Amt,
const LLT HalfTy, const LLT AmtTy) {
unsigned InL = MRI.createGenericVirtualRegister(HalfTy);
unsigned InH = MRI.createGenericVirtualRegister(HalfTy);
MIRBuilder.buildUnmerge({InL, InH}, MI.getOperand(1).getReg());
if (Amt.isNullValue()) {
MIRBuilder.buildMerge(MI.getOperand(0).getReg(), {InL, InH});
MI.eraseFromParent();
return Legalized;
}
LLT NVT = HalfTy;
unsigned NVTBits = HalfTy.getSizeInBits();
unsigned VTBits = 2 * NVTBits;
SrcOp Lo(0), Hi(0);
if (MI.getOpcode() == TargetOpcode::G_SHL) {
if (Amt.ugt(VTBits)) {
Lo = Hi = MIRBuilder.buildConstant(NVT, 0);
} else if (Amt.ugt(NVTBits)) {
Lo = MIRBuilder.buildConstant(NVT, 0);
Hi = MIRBuilder.buildShl(NVT, InL,
MIRBuilder.buildConstant(AmtTy, Amt - NVTBits));
} else if (Amt == NVTBits) {
Lo = MIRBuilder.buildConstant(NVT, 0);
Hi = InL;
} else {
Lo = MIRBuilder.buildShl(NVT, InL, MIRBuilder.buildConstant(AmtTy, Amt));
auto OrLHS =
MIRBuilder.buildShl(NVT, InH, MIRBuilder.buildConstant(AmtTy, Amt));
auto OrRHS = MIRBuilder.buildLShr(
NVT, InL, MIRBuilder.buildConstant(AmtTy, -Amt + NVTBits));
Hi = MIRBuilder.buildOr(NVT, OrLHS, OrRHS);
}
} else if (MI.getOpcode() == TargetOpcode::G_LSHR) {
if (Amt.ugt(VTBits)) {
Lo = Hi = MIRBuilder.buildConstant(NVT, 0);
} else if (Amt.ugt(NVTBits)) {
Lo = MIRBuilder.buildLShr(NVT, InH,
MIRBuilder.buildConstant(AmtTy, Amt - NVTBits));
Hi = MIRBuilder.buildConstant(NVT, 0);
} else if (Amt == NVTBits) {
Lo = InH;
Hi = MIRBuilder.buildConstant(NVT, 0);
} else {
auto ShiftAmtConst = MIRBuilder.buildConstant(AmtTy, Amt);
auto OrLHS = MIRBuilder.buildLShr(NVT, InL, ShiftAmtConst);
auto OrRHS = MIRBuilder.buildShl(
NVT, InH, MIRBuilder.buildConstant(AmtTy, -Amt + NVTBits));
Lo = MIRBuilder.buildOr(NVT, OrLHS, OrRHS);
Hi = MIRBuilder.buildLShr(NVT, InH, ShiftAmtConst);
}
} else {
if (Amt.ugt(VTBits)) {
Hi = Lo = MIRBuilder.buildAShr(
NVT, InH, MIRBuilder.buildConstant(AmtTy, NVTBits - 1));
} else if (Amt.ugt(NVTBits)) {
Lo = MIRBuilder.buildAShr(NVT, InH,
MIRBuilder.buildConstant(AmtTy, Amt - NVTBits));
Hi = MIRBuilder.buildAShr(NVT, InH,
MIRBuilder.buildConstant(AmtTy, NVTBits - 1));
} else if (Amt == NVTBits) {
Lo = InH;
Hi = MIRBuilder.buildAShr(NVT, InH,
MIRBuilder.buildConstant(AmtTy, NVTBits - 1));
} else {
auto ShiftAmtConst = MIRBuilder.buildConstant(AmtTy, Amt);
auto OrLHS = MIRBuilder.buildLShr(NVT, InL, ShiftAmtConst);
auto OrRHS = MIRBuilder.buildShl(
NVT, InH, MIRBuilder.buildConstant(AmtTy, -Amt + NVTBits));
Lo = MIRBuilder.buildOr(NVT, OrLHS, OrRHS);
Hi = MIRBuilder.buildAShr(NVT, InH, ShiftAmtConst);
}
}
MIRBuilder.buildMerge(MI.getOperand(0).getReg(), {Lo.getReg(), Hi.getReg()});
MI.eraseFromParent();
return Legalized;
}
// TODO: Optimize if constant shift amount.
LegalizerHelper::LegalizeResult
LegalizerHelper::narrowScalarShift(MachineInstr &MI, unsigned TypeIdx,
LLT RequestedTy) {
if (TypeIdx == 1) {
Observer.changingInstr(MI);
narrowScalarSrc(MI, RequestedTy, 2);
Observer.changedInstr(MI);
return Legalized;
}
unsigned DstReg = MI.getOperand(0).getReg();
LLT DstTy = MRI.getType(DstReg);
if (DstTy.isVector())
return UnableToLegalize;
unsigned Amt = MI.getOperand(2).getReg();
LLT ShiftAmtTy = MRI.getType(Amt);
const unsigned DstEltSize = DstTy.getScalarSizeInBits();
if (DstEltSize % 2 != 0)
return UnableToLegalize;
// Ignore the input type. We can only go to exactly half the size of the
// input. If that isn't small enough, the resulting pieces will be further
// legalized.
const unsigned NewBitSize = DstEltSize / 2;
const LLT HalfTy = LLT::scalar(NewBitSize);
const LLT CondTy = LLT::scalar(1);
if (const MachineInstr *KShiftAmt =
getOpcodeDef(TargetOpcode::G_CONSTANT, Amt, MRI)) {
return narrowScalarShiftByConstant(
MI, KShiftAmt->getOperand(1).getCImm()->getValue(), HalfTy, ShiftAmtTy);
}
// TODO: Expand with known bits.
// Handle the fully general expansion by an unknown amount.
auto NewBits = MIRBuilder.buildConstant(ShiftAmtTy, NewBitSize);
unsigned InL = MRI.createGenericVirtualRegister(HalfTy);
unsigned InH = MRI.createGenericVirtualRegister(HalfTy);
MIRBuilder.buildUnmerge({InL, InH}, MI.getOperand(1).getReg());
auto AmtExcess = MIRBuilder.buildSub(ShiftAmtTy, Amt, NewBits);
auto AmtLack = MIRBuilder.buildSub(ShiftAmtTy, NewBits, Amt);
auto Zero = MIRBuilder.buildConstant(ShiftAmtTy, 0);
auto IsShort = MIRBuilder.buildICmp(ICmpInst::ICMP_ULT, CondTy, Amt, NewBits);
auto IsZero = MIRBuilder.buildICmp(ICmpInst::ICMP_EQ, CondTy, Amt, Zero);
unsigned ResultRegs[2];
switch (MI.getOpcode()) {
case TargetOpcode::G_SHL: {
// Short: ShAmt < NewBitSize
auto LoS = MIRBuilder.buildShl(HalfTy, InH, Amt);
auto OrLHS = MIRBuilder.buildShl(HalfTy, InH, Amt);
auto OrRHS = MIRBuilder.buildLShr(HalfTy, InL, AmtLack);
auto HiS = MIRBuilder.buildOr(HalfTy, OrLHS, OrRHS);
// Long: ShAmt >= NewBitSize
auto LoL = MIRBuilder.buildConstant(HalfTy, 0); // Lo part is zero.
auto HiL = MIRBuilder.buildShl(HalfTy, InL, AmtExcess); // Hi from Lo part.
auto Lo = MIRBuilder.buildSelect(HalfTy, IsShort, LoS, LoL);
auto Hi = MIRBuilder.buildSelect(
HalfTy, IsZero, InH, MIRBuilder.buildSelect(HalfTy, IsShort, HiS, HiL));
ResultRegs[0] = Lo.getReg(0);
ResultRegs[1] = Hi.getReg(0);
break;
}
case TargetOpcode::G_LSHR: {
// Short: ShAmt < NewBitSize
auto HiS = MIRBuilder.buildLShr(HalfTy, InH, Amt);
auto OrLHS = MIRBuilder.buildLShr(HalfTy, InL, Amt);
auto OrRHS = MIRBuilder.buildShl(HalfTy, InH, AmtLack);
auto LoS = MIRBuilder.buildOr(HalfTy, OrLHS, OrRHS);
// Long: ShAmt >= NewBitSize
auto HiL = MIRBuilder.buildConstant(HalfTy, 0); // Hi part is zero.
auto LoL = MIRBuilder.buildLShr(HalfTy, InH, AmtExcess); // Lo from Hi part.
auto Lo = MIRBuilder.buildSelect(
HalfTy, IsZero, InL, MIRBuilder.buildSelect(HalfTy, IsShort, LoS, LoL));
auto Hi = MIRBuilder.buildSelect(HalfTy, IsShort, HiS, HiL);
ResultRegs[0] = Lo.getReg(0);
ResultRegs[1] = Hi.getReg(0);
break;
}
case TargetOpcode::G_ASHR: {
// Short: ShAmt < NewBitSize
auto HiS = MIRBuilder.buildAShr(HalfTy, InH, Amt);
auto OrLHS = MIRBuilder.buildLShr(HalfTy, InL, Amt);
auto OrRHS = MIRBuilder.buildLShr(HalfTy, InH, AmtLack);
auto LoS = MIRBuilder.buildOr(HalfTy, OrLHS, OrRHS);
// Long: ShAmt >= NewBitSize
// Sign of Hi part.
auto HiL = MIRBuilder.buildAShr(
HalfTy, InH, MIRBuilder.buildConstant(ShiftAmtTy, NewBitSize - 1));
auto LoL = MIRBuilder.buildAShr(HalfTy, InH, AmtExcess); // Lo from Hi part.
auto Lo = MIRBuilder.buildSelect(
HalfTy, IsZero, InL, MIRBuilder.buildSelect(HalfTy, IsShort, LoS, LoL));
auto Hi = MIRBuilder.buildSelect(HalfTy, IsShort, HiS, HiL);
ResultRegs[0] = Lo.getReg(0);
ResultRegs[1] = Hi.getReg(0);
break;
}
default:
llvm_unreachable("not a shift");
}
MIRBuilder.buildMerge(DstReg, ResultRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::moreElementsVectorPhi(MachineInstr &MI, unsigned TypeIdx,
LLT MoreTy) {
assert(TypeIdx == 0 && "Expecting only Idx 0");
Observer.changingInstr(MI);
for (unsigned I = 1, E = MI.getNumOperands(); I != E; I += 2) {
MachineBasicBlock &OpMBB = *MI.getOperand(I + 1).getMBB();
MIRBuilder.setInsertPt(OpMBB, OpMBB.getFirstTerminator());
moreElementsVectorSrc(MI, MoreTy, I);
}
MachineBasicBlock &MBB = *MI.getParent();
MIRBuilder.setInsertPt(MBB, --MBB.getFirstNonPHI());
moreElementsVectorDst(MI, MoreTy, 0);
Observer.changedInstr(MI);
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::moreElementsVector(MachineInstr &MI, unsigned TypeIdx,
LLT MoreTy) {
MIRBuilder.setInstr(MI);
unsigned Opc = MI.getOpcode();
switch (Opc) {
case TargetOpcode::G_IMPLICIT_DEF: {
Observer.changingInstr(MI);
moreElementsVectorDst(MI, MoreTy, 0);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_AND:
case TargetOpcode::G_OR:
case TargetOpcode::G_XOR: {
Observer.changingInstr(MI);
moreElementsVectorSrc(MI, MoreTy, 1);
moreElementsVectorSrc(MI, MoreTy, 2);
moreElementsVectorDst(MI, MoreTy, 0);
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_EXTRACT:
if (TypeIdx != 1)
return UnableToLegalize;
Observer.changingInstr(MI);
moreElementsVectorSrc(MI, MoreTy, 1);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_INSERT:
if (TypeIdx != 0)
return UnableToLegalize;
Observer.changingInstr(MI);
moreElementsVectorSrc(MI, MoreTy, 1);
moreElementsVectorDst(MI, MoreTy, 0);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_SELECT:
if (TypeIdx != 0)
return UnableToLegalize;
if (MRI.getType(MI.getOperand(1).getReg()).isVector())
return UnableToLegalize;
Observer.changingInstr(MI);
moreElementsVectorSrc(MI, MoreTy, 2);
moreElementsVectorSrc(MI, MoreTy, 3);
moreElementsVectorDst(MI, MoreTy, 0);
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_PHI:
return moreElementsVectorPhi(MI, TypeIdx, MoreTy);
default:
return UnableToLegalize;
}
}
void LegalizerHelper::multiplyRegisters(SmallVectorImpl<unsigned> &DstRegs,
ArrayRef<unsigned> Src1Regs,
ArrayRef<unsigned> Src2Regs,
LLT NarrowTy) {
MachineIRBuilder &B = MIRBuilder;
unsigned SrcParts = Src1Regs.size();
unsigned DstParts = DstRegs.size();
unsigned DstIdx = 0; // Low bits of the result.
unsigned FactorSum =
B.buildMul(NarrowTy, Src1Regs[DstIdx], Src2Regs[DstIdx]).getReg(0);
DstRegs[DstIdx] = FactorSum;
unsigned CarrySumPrevDstIdx;
SmallVector<unsigned, 4> Factors;
for (DstIdx = 1; DstIdx < DstParts; DstIdx++) {
// Collect low parts of muls for DstIdx.
for (unsigned i = DstIdx + 1 < SrcParts ? 0 : DstIdx - SrcParts + 1;
i <= std::min(DstIdx, SrcParts - 1); ++i) {
MachineInstrBuilder Mul =
B.buildMul(NarrowTy, Src1Regs[DstIdx - i], Src2Regs[i]);
Factors.push_back(Mul.getReg(0));
}
// Collect high parts of muls from previous DstIdx.
for (unsigned i = DstIdx < SrcParts ? 0 : DstIdx - SrcParts;
i <= std::min(DstIdx - 1, SrcParts - 1); ++i) {
MachineInstrBuilder Umulh =
B.buildUMulH(NarrowTy, Src1Regs[DstIdx - 1 - i], Src2Regs[i]);
Factors.push_back(Umulh.getReg(0));
}
// Add CarrySum from additons calculated for previous DstIdx.
if (DstIdx != 1) {
Factors.push_back(CarrySumPrevDstIdx);
}
unsigned CarrySum = 0;
// Add all factors and accumulate all carries into CarrySum.
if (DstIdx != DstParts - 1) {
MachineInstrBuilder Uaddo =
B.buildUAddo(NarrowTy, LLT::scalar(1), Factors[0], Factors[1]);
FactorSum = Uaddo.getReg(0);
CarrySum = B.buildZExt(NarrowTy, Uaddo.getReg(1)).getReg(0);
for (unsigned i = 2; i < Factors.size(); ++i) {
MachineInstrBuilder Uaddo =
B.buildUAddo(NarrowTy, LLT::scalar(1), FactorSum, Factors[i]);
FactorSum = Uaddo.getReg(0);
MachineInstrBuilder Carry = B.buildZExt(NarrowTy, Uaddo.getReg(1));
CarrySum = B.buildAdd(NarrowTy, CarrySum, Carry).getReg(0);
}
} else {
// Since value for the next index is not calculated, neither is CarrySum.
FactorSum = B.buildAdd(NarrowTy, Factors[0], Factors[1]).getReg(0);
for (unsigned i = 2; i < Factors.size(); ++i)
FactorSum = B.buildAdd(NarrowTy, FactorSum, Factors[i]).getReg(0);
}
CarrySumPrevDstIdx = CarrySum;
DstRegs[DstIdx] = FactorSum;
Factors.clear();
}
}
LegalizerHelper::LegalizeResult
LegalizerHelper::narrowScalarMul(MachineInstr &MI, LLT NarrowTy) {
unsigned DstReg = MI.getOperand(0).getReg();
unsigned Src1 = MI.getOperand(1).getReg();
unsigned Src2 = MI.getOperand(2).getReg();
LLT Ty = MRI.getType(DstReg);
if (Ty.isVector())
return UnableToLegalize;
unsigned SrcSize = MRI.getType(Src1).getSizeInBits();
unsigned DstSize = Ty.getSizeInBits();
unsigned NarrowSize = NarrowTy.getSizeInBits();
if (DstSize % NarrowSize != 0 || SrcSize % NarrowSize != 0)
return UnableToLegalize;
unsigned NumDstParts = DstSize / NarrowSize;
unsigned NumSrcParts = SrcSize / NarrowSize;
bool IsMulHigh = MI.getOpcode() == TargetOpcode::G_UMULH;
unsigned DstTmpParts = NumDstParts * (IsMulHigh ? 2 : 1);
SmallVector<unsigned, 2> Src1Parts, Src2Parts, DstTmpRegs;
extractParts(Src1, NarrowTy, NumSrcParts, Src1Parts);
extractParts(Src2, NarrowTy, NumSrcParts, Src2Parts);
DstTmpRegs.resize(DstTmpParts);
multiplyRegisters(DstTmpRegs, Src1Parts, Src2Parts, NarrowTy);
// Take only high half of registers if this is high mul.
ArrayRef<unsigned> DstRegs(
IsMulHigh ? &DstTmpRegs[DstTmpParts / 2] : &DstTmpRegs[0], NumDstParts);
MIRBuilder.buildMerge(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::narrowScalarExtract(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
if (TypeIdx != 1)
return UnableToLegalize;
uint64_t NarrowSize = NarrowTy.getSizeInBits();
int64_t SizeOp1 = MRI.getType(MI.getOperand(1).getReg()).getSizeInBits();
// FIXME: add support for when SizeOp1 isn't an exact multiple of
// NarrowSize.
if (SizeOp1 % NarrowSize != 0)
return UnableToLegalize;
int NumParts = SizeOp1 / NarrowSize;
SmallVector<unsigned, 2> SrcRegs, DstRegs;
SmallVector<uint64_t, 2> Indexes;
extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, SrcRegs);
unsigned OpReg = MI.getOperand(0).getReg();
uint64_t OpStart = MI.getOperand(2).getImm();
uint64_t OpSize = MRI.getType(OpReg).getSizeInBits();
for (int i = 0; i < NumParts; ++i) {
unsigned SrcStart = i * NarrowSize;
if (SrcStart + NarrowSize <= OpStart || SrcStart >= OpStart + OpSize) {
// No part of the extract uses this subregister, ignore it.
continue;
} else if (SrcStart == OpStart && NarrowTy == MRI.getType(OpReg)) {
// The entire subregister is extracted, forward the value.
DstRegs.push_back(SrcRegs[i]);
continue;
}
// OpSegStart is where this destination segment would start in OpReg if it
// extended infinitely in both directions.
int64_t ExtractOffset;
uint64_t SegSize;
if (OpStart < SrcStart) {
ExtractOffset = 0;
SegSize = std::min(NarrowSize, OpStart + OpSize - SrcStart);
} else {
ExtractOffset = OpStart - SrcStart;
SegSize = std::min(SrcStart + NarrowSize - OpStart, OpSize);
}
unsigned SegReg = SrcRegs[i];
if (ExtractOffset != 0 || SegSize != NarrowSize) {
// A genuine extract is needed.
SegReg = MRI.createGenericVirtualRegister(LLT::scalar(SegSize));
MIRBuilder.buildExtract(SegReg, SrcRegs[i], ExtractOffset);
}
DstRegs.push_back(SegReg);
}
unsigned DstReg = MI.getOperand(0).getReg();
if(MRI.getType(DstReg).isVector())
MIRBuilder.buildBuildVector(DstReg, DstRegs);
else
MIRBuilder.buildMerge(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::narrowScalarInsert(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
// FIXME: Don't know how to handle secondary types yet.
if (TypeIdx != 0)
return UnableToLegalize;
uint64_t SizeOp0 = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
uint64_t NarrowSize = NarrowTy.getSizeInBits();
// FIXME: add support for when SizeOp0 isn't an exact multiple of
// NarrowSize.
if (SizeOp0 % NarrowSize != 0)
return UnableToLegalize;
int NumParts = SizeOp0 / NarrowSize;
SmallVector<unsigned, 2> SrcRegs, DstRegs;
SmallVector<uint64_t, 2> Indexes;
extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, SrcRegs);
unsigned OpReg = MI.getOperand(2).getReg();
uint64_t OpStart = MI.getOperand(3).getImm();
uint64_t OpSize = MRI.getType(OpReg).getSizeInBits();
for (int i = 0; i < NumParts; ++i) {
unsigned DstStart = i * NarrowSize;
if (DstStart + NarrowSize <= OpStart || DstStart >= OpStart + OpSize) {
// No part of the insert affects this subregister, forward the original.
DstRegs.push_back(SrcRegs[i]);
continue;
} else if (DstStart == OpStart && NarrowTy == MRI.getType(OpReg)) {
// The entire subregister is defined by this insert, forward the new
// value.
DstRegs.push_back(OpReg);
continue;
}
// OpSegStart is where this destination segment would start in OpReg if it
// extended infinitely in both directions.
int64_t ExtractOffset, InsertOffset;
uint64_t SegSize;
if (OpStart < DstStart) {
InsertOffset = 0;
ExtractOffset = DstStart - OpStart;
SegSize = std::min(NarrowSize, OpStart + OpSize - DstStart);
} else {
InsertOffset = OpStart - DstStart;
ExtractOffset = 0;
SegSize =
std::min(NarrowSize - InsertOffset, OpStart + OpSize - DstStart);
}
unsigned SegReg = OpReg;
if (ExtractOffset != 0 || SegSize != OpSize) {
// A genuine extract is needed.
SegReg = MRI.createGenericVirtualRegister(LLT::scalar(SegSize));
MIRBuilder.buildExtract(SegReg, OpReg, ExtractOffset);
}
unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy);
MIRBuilder.buildInsert(DstReg, SrcRegs[i], SegReg, InsertOffset);
DstRegs.push_back(DstReg);
}
assert(DstRegs.size() == (unsigned)NumParts && "not all parts covered");
unsigned DstReg = MI.getOperand(0).getReg();
if(MRI.getType(DstReg).isVector())
MIRBuilder.buildBuildVector(DstReg, DstRegs);
else
MIRBuilder.buildMerge(DstReg, DstRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::narrowScalarBasic(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
unsigned DstReg = MI.getOperand(0).getReg();
LLT DstTy = MRI.getType(DstReg);
assert(MI.getNumOperands() == 3 && TypeIdx == 0);
SmallVector<unsigned, 4> DstRegs, DstLeftoverRegs;
SmallVector<unsigned, 4> Src0Regs, Src0LeftoverRegs;
SmallVector<unsigned, 4> Src1Regs, Src1LeftoverRegs;
LLT LeftoverTy;
if (!extractParts(MI.getOperand(1).getReg(), DstTy, NarrowTy, LeftoverTy,
Src0Regs, Src0LeftoverRegs))
return UnableToLegalize;
LLT Unused;
if (!extractParts(MI.getOperand(2).getReg(), DstTy, NarrowTy, Unused,
Src1Regs, Src1LeftoverRegs))
llvm_unreachable("inconsistent extractParts result");
for (unsigned I = 0, E = Src1Regs.size(); I != E; ++I) {
auto Inst = MIRBuilder.buildInstr(MI.getOpcode(), {NarrowTy},
{Src0Regs[I], Src1Regs[I]});
DstRegs.push_back(Inst->getOperand(0).getReg());
}
for (unsigned I = 0, E = Src1LeftoverRegs.size(); I != E; ++I) {
auto Inst = MIRBuilder.buildInstr(
MI.getOpcode(),
{LeftoverTy}, {Src0LeftoverRegs[I], Src1LeftoverRegs[I]});
DstLeftoverRegs.push_back(Inst->getOperand(0).getReg());
}
insertParts(DstReg, DstTy, NarrowTy, DstRegs,
LeftoverTy, DstLeftoverRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::narrowScalarSelect(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
if (TypeIdx != 0)
return UnableToLegalize;
unsigned CondReg = MI.getOperand(1).getReg();
LLT CondTy = MRI.getType(CondReg);
if (CondTy.isVector()) // TODO: Handle vselect
return UnableToLegalize;
unsigned DstReg = MI.getOperand(0).getReg();
LLT DstTy = MRI.getType(DstReg);
SmallVector<unsigned, 4> DstRegs, DstLeftoverRegs;
SmallVector<unsigned, 4> Src1Regs, Src1LeftoverRegs;
SmallVector<unsigned, 4> Src2Regs, Src2LeftoverRegs;
LLT LeftoverTy;
if (!extractParts(MI.getOperand(2).getReg(), DstTy, NarrowTy, LeftoverTy,
Src1Regs, Src1LeftoverRegs))
return UnableToLegalize;
LLT Unused;
if (!extractParts(MI.getOperand(3).getReg(), DstTy, NarrowTy, Unused,
Src2Regs, Src2LeftoverRegs))
llvm_unreachable("inconsistent extractParts result");
for (unsigned I = 0, E = Src1Regs.size(); I != E; ++I) {
auto Select = MIRBuilder.buildSelect(NarrowTy,
CondReg, Src1Regs[I], Src2Regs[I]);
DstRegs.push_back(Select->getOperand(0).getReg());
}
for (unsigned I = 0, E = Src1LeftoverRegs.size(); I != E; ++I) {
auto Select = MIRBuilder.buildSelect(
LeftoverTy, CondReg, Src1LeftoverRegs[I], Src2LeftoverRegs[I]);
DstLeftoverRegs.push_back(Select->getOperand(0).getReg());
}
insertParts(DstReg, DstTy, NarrowTy, DstRegs,
LeftoverTy, DstLeftoverRegs);
MI.eraseFromParent();
return Legalized;
}
LegalizerHelper::LegalizeResult
LegalizerHelper::lowerBitCount(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
unsigned Opc = MI.getOpcode();
auto &TII = *MI.getMF()->getSubtarget().getInstrInfo();
auto isSupported = [this](const LegalityQuery &Q) {
auto QAction = LI.getAction(Q).Action;
return QAction == Legal || QAction == Libcall || QAction == Custom;
};
switch (Opc) {
default:
return UnableToLegalize;
case TargetOpcode::G_CTLZ_ZERO_UNDEF: {
// This trivially expands to CTLZ.
Observer.changingInstr(MI);
MI.setDesc(TII.get(TargetOpcode::G_CTLZ));
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_CTLZ: {
unsigned SrcReg = MI.getOperand(1).getReg();
unsigned Len = Ty.getSizeInBits();
if (isSupported({TargetOpcode::G_CTLZ_ZERO_UNDEF, {Ty, Ty}})) {
// If CTLZ_ZERO_UNDEF is supported, emit that and a select for zero.
auto MIBCtlzZU = MIRBuilder.buildInstr(TargetOpcode::G_CTLZ_ZERO_UNDEF,
{Ty}, {SrcReg});
auto MIBZero = MIRBuilder.buildConstant(Ty, 0);
auto MIBLen = MIRBuilder.buildConstant(Ty, Len);
auto MIBICmp = MIRBuilder.buildICmp(CmpInst::ICMP_EQ, LLT::scalar(1),
SrcReg, MIBZero);
MIRBuilder.buildSelect(MI.getOperand(0).getReg(), MIBICmp, MIBLen,
MIBCtlzZU);
MI.eraseFromParent();
return Legalized;
}
// for now, we do this:
// NewLen = NextPowerOf2(Len);
// x = x | (x >> 1);
// x = x | (x >> 2);
// ...
// x = x | (x >>16);
// x = x | (x >>32); // for 64-bit input
// Upto NewLen/2
// return Len - popcount(x);
//
// Ref: "Hacker's Delight" by Henry Warren
unsigned Op = SrcReg;
unsigned NewLen = PowerOf2Ceil(Len);
for (unsigned i = 0; (1U << i) <= (NewLen / 2); ++i) {
auto MIBShiftAmt = MIRBuilder.buildConstant(Ty, 1ULL << i);
auto MIBOp = MIRBuilder.buildInstr(
TargetOpcode::G_OR, {Ty},
{Op, MIRBuilder.buildInstr(TargetOpcode::G_LSHR, {Ty},
{Op, MIBShiftAmt})});
Op = MIBOp->getOperand(0).getReg();
}
auto MIBPop = MIRBuilder.buildInstr(TargetOpcode::G_CTPOP, {Ty}, {Op});
MIRBuilder.buildInstr(TargetOpcode::G_SUB, {MI.getOperand(0).getReg()},
{MIRBuilder.buildConstant(Ty, Len), MIBPop});
MI.eraseFromParent();
return Legalized;
}
case TargetOpcode::G_CTTZ_ZERO_UNDEF: {
// This trivially expands to CTTZ.
Observer.changingInstr(MI);
MI.setDesc(TII.get(TargetOpcode::G_CTTZ));
Observer.changedInstr(MI);
return Legalized;
}
case TargetOpcode::G_CTTZ: {
unsigned SrcReg = MI.getOperand(1).getReg();
unsigned Len = Ty.getSizeInBits();
if (isSupported({TargetOpcode::G_CTTZ_ZERO_UNDEF, {Ty, Ty}})) {
// If CTTZ_ZERO_UNDEF is legal or custom, emit that and a select with
// zero.
auto MIBCttzZU = MIRBuilder.buildInstr(TargetOpcode::G_CTTZ_ZERO_UNDEF,
{Ty}, {SrcReg});
auto MIBZero = MIRBuilder.buildConstant(Ty, 0);
auto MIBLen = MIRBuilder.buildConstant(Ty, Len);
auto MIBICmp = MIRBuilder.buildICmp(CmpInst::ICMP_EQ, LLT::scalar(1),
SrcReg, MIBZero);
MIRBuilder.buildSelect(MI.getOperand(0).getReg(), MIBICmp, MIBLen,
MIBCttzZU);
MI.eraseFromParent();
return Legalized;
}
// for now, we use: { return popcount(~x & (x - 1)); }
// unless the target has ctlz but not ctpop, in which case we use:
// { return 32 - nlz(~x & (x-1)); }
// Ref: "Hacker's Delight" by Henry Warren
auto MIBCstNeg1 = MIRBuilder.buildConstant(Ty, -1);
auto MIBNot =
MIRBuilder.buildInstr(TargetOpcode::G_XOR, {Ty}, {SrcReg, MIBCstNeg1});
auto MIBTmp = MIRBuilder.buildInstr(
TargetOpcode::G_AND, {Ty},
{MIBNot, MIRBuilder.buildInstr(TargetOpcode::G_ADD, {Ty},
{SrcReg, MIBCstNeg1})});
if (!isSupported({TargetOpcode::G_CTPOP, {Ty, Ty}}) &&
isSupported({TargetOpcode::G_CTLZ, {Ty, Ty}})) {
auto MIBCstLen = MIRBuilder.buildConstant(Ty, Len);
MIRBuilder.buildInstr(
TargetOpcode::G_SUB, {MI.getOperand(0).getReg()},
{MIBCstLen,
MIRBuilder.buildInstr(TargetOpcode::G_CTLZ, {Ty}, {MIBTmp})});
MI.eraseFromParent();
return Legalized;
}
MI.setDesc(TII.get(TargetOpcode::G_CTPOP));
MI.getOperand(1).setReg(MIBTmp->getOperand(0).getReg());
return Legalized;
}
}
}