| //===-- llvm/CodeGen/GlobalISel/LegalizerHelper.cpp -----------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| /// \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/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; |
| |
| LegalizerHelper::LegalizerHelper(MachineFunction &MF) |
| : MRI(MF.getRegInfo()), LI(*MF.getSubtarget().getLegalizerInfo()) { |
| MIRBuilder.setMF(MF); |
| } |
| |
| LegalizerHelper::LegalizerHelper(MachineFunction &MF, const LegalizerInfo &LI) |
| : MRI(MF.getRegInfo()), LI(LI) { |
| MIRBuilder.setMF(MF); |
| } |
| 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 Custom: |
| LLVM_DEBUG(dbgs() << ".. Custom legalization\n"); |
| return LI.legalizeCustom(MI, MRI, MIRBuilder) ? 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); |
| } |
| |
| static RTLIB::Libcall getRTLibDesc(unsigned Opcode, unsigned Size) { |
| switch (Opcode) { |
| case TargetOpcode::G_SDIV: |
| assert(Size == 32 && "Unsupported size"); |
| return RTLIB::SDIV_I32; |
| case TargetOpcode::G_UDIV: |
| assert(Size == 32 && "Unsupported size"); |
| return RTLIB::UDIV_I32; |
| case TargetOpcode::G_SREM: |
| assert(Size == 32 && "Unsupported size"); |
| return RTLIB::SREM_I32; |
| case TargetOpcode::G_UREM: |
| assert(Size == 32 && "Unsupported size"); |
| return RTLIB::UREM_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_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; |
| } |
| 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: { |
| Type *HLTy = Type::getInt32Ty(Ctx); |
| 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: { |
| 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) { |
| // FIXME: Don't know how to handle secondary types yet. |
| if (TypeIdx != 0 && MI.getOpcode() != TargetOpcode::G_EXTRACT) |
| return UnableToLegalize; |
| |
| 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()); |
| MIRBuilder.buildMerge(MI.getOperand(0).getReg(), DstRegs); |
| 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(); |
| MIRBuilder.buildMerge(DstReg, DstRegs); |
| MI.eraseFromParent(); |
| return Legalized; |
| } |
| case TargetOpcode::G_EXTRACT: { |
| if (TypeIdx != 1) |
| return UnableToLegalize; |
| |
| 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); |
| } |
| |
| MIRBuilder.buildMerge(MI.getOperand(0).getReg(), DstRegs); |
| MI.eraseFromParent(); |
| return Legalized; |
| } |
| case TargetOpcode::G_INSERT: { |
| // 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"); |
| MIRBuilder.buildMerge(MI.getOperand(0).getReg(), DstRegs); |
| MI.eraseFromParent(); |
| return Legalized; |
| } |
| case TargetOpcode::G_LOAD: { |
| // FIXME: add support for when SizeOp0 isn't an exact multiple of |
| // NarrowSize. |
| if (SizeOp0 % NarrowSize != 0) |
| return UnableToLegalize; |
| |
| const auto &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; |
| |
| int NumParts = SizeOp0 / NarrowSize; |
| LLT OffsetTy = LLT::scalar( |
| MRI.getType(MI.getOperand(1).getReg()).getScalarSizeInBits()); |
| |
| SmallVector<unsigned, 2> DstRegs; |
| for (int i = 0; i < NumParts; ++i) { |
| unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy); |
| unsigned SrcReg = 0; |
| unsigned Adjustment = i * NarrowSize / 8; |
| |
| MachineMemOperand *SplitMMO = MIRBuilder.getMF().getMachineMemOperand( |
| MMO.getPointerInfo().getWithOffset(Adjustment), MMO.getFlags(), |
| NarrowSize / 8, i == 0 ? MMO.getAlignment() : NarrowSize / 8, |
| MMO.getAAInfo(), MMO.getRanges(), MMO.getSyncScopeID(), |
| MMO.getOrdering(), MMO.getFailureOrdering()); |
| |
| MIRBuilder.materializeGEP(SrcReg, MI.getOperand(1).getReg(), OffsetTy, |
| Adjustment); |
| |
| MIRBuilder.buildLoad(DstReg, SrcReg, *SplitMMO); |
| |
| DstRegs.push_back(DstReg); |
| } |
| unsigned DstReg = MI.getOperand(0).getReg(); |
| MIRBuilder.buildMerge(DstReg, DstRegs); |
| MI.eraseFromParent(); |
| return Legalized; |
| } |
| case TargetOpcode::G_STORE: { |
| // FIXME: add support for when SizeOp0 isn't an exact multiple of |
| // NarrowSize. |
| if (SizeOp0 % NarrowSize != 0) |
| return UnableToLegalize; |
| |
| const auto &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; |
| |
| int NumParts = SizeOp0 / NarrowSize; |
| LLT OffsetTy = LLT::scalar( |
| MRI.getType(MI.getOperand(1).getReg()).getScalarSizeInBits()); |
| |
| SmallVector<unsigned, 2> SrcRegs; |
| extractParts(MI.getOperand(0).getReg(), NarrowTy, NumParts, SrcRegs); |
| |
| for (int i = 0; i < NumParts; ++i) { |
| unsigned DstReg = 0; |
| unsigned Adjustment = i * NarrowSize / 8; |
| |
| MachineMemOperand *SplitMMO = MIRBuilder.getMF().getMachineMemOperand( |
| MMO.getPointerInfo().getWithOffset(Adjustment), MMO.getFlags(), |
| NarrowSize / 8, i == 0 ? MMO.getAlignment() : NarrowSize / 8, |
| MMO.getAAInfo(), MMO.getRanges(), MMO.getSyncScopeID(), |
| MMO.getOrdering(), MMO.getFailureOrdering()); |
| |
| MIRBuilder.materializeGEP(DstReg, MI.getOperand(1).getReg(), OffsetTy, |
| Adjustment); |
| |
| MIRBuilder.buildStore(SrcRegs[i], DstReg, *SplitMMO); |
| } |
| MI.eraseFromParent(); |
| return Legalized; |
| } |
| case TargetOpcode::G_CONSTANT: { |
| // FIXME: add support for when SizeOp0 isn't an exact multiple of |
| // NarrowSize. |
| if (SizeOp0 % NarrowSize != 0) |
| return UnableToLegalize; |
| int NumParts = SizeOp0 / NarrowSize; |
| const APInt &Cst = MI.getOperand(1).getCImm()->getValue(); |
| LLVMContext &Ctx = MIRBuilder.getMF().getFunction().getContext(); |
| |
| SmallVector<unsigned, 2> DstRegs; |
| for (int i = 0; i < NumParts; ++i) { |
| unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy); |
| ConstantInt *CI = |
| ConstantInt::get(Ctx, Cst.lshr(NarrowSize * i).trunc(NarrowSize)); |
| MIRBuilder.buildConstant(DstReg, *CI); |
| DstRegs.push_back(DstReg); |
| } |
| unsigned DstReg = MI.getOperand(0).getReg(); |
| MIRBuilder.buildMerge(DstReg, DstRegs); |
| MI.eraseFromParent(); |
| return Legalized; |
| } |
| case TargetOpcode::G_OR: { |
| // 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 |
| |
| // FIXME: add support for when SizeOp0 isn't an exact multiple of |
| // NarrowSize. |
| if (SizeOp0 % NarrowSize != 0) |
| return UnableToLegalize; |
| int NumParts = SizeOp0 / NarrowSize; |
| |
| // List the registers where the destination will be scattered. |
| SmallVector<unsigned, 2> DstRegs; |
| // List the registers where the first argument will be split. |
| SmallVector<unsigned, 2> SrcsReg1; |
| // List the registers where the second argument will be split. |
| SmallVector<unsigned, 2> SrcsReg2; |
| // Create all the temporary registers. |
| for (int i = 0; i < NumParts; ++i) { |
| unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy); |
| unsigned SrcReg1 = MRI.createGenericVirtualRegister(NarrowTy); |
| unsigned SrcReg2 = MRI.createGenericVirtualRegister(NarrowTy); |
| |
| DstRegs.push_back(DstReg); |
| SrcsReg1.push_back(SrcReg1); |
| SrcsReg2.push_back(SrcReg2); |
| } |
| // Explode the big arguments into smaller chunks. |
| MIRBuilder.buildUnmerge(SrcsReg1, MI.getOperand(1).getReg()); |
| MIRBuilder.buildUnmerge(SrcsReg2, MI.getOperand(2).getReg()); |
| |
| // Do the operation on each small part. |
| for (int i = 0; i < NumParts; ++i) |
| MIRBuilder.buildOr(DstRegs[i], SrcsReg1[i], SrcsReg2[i]); |
| |
| // Gather the destination registers into the final destination. |
| unsigned DstReg = MI.getOperand(0).getReg(); |
| MIRBuilder.buildMerge(DstReg, DstRegs); |
| MI.eraseFromParent(); |
| 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::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); |
| } |
| |
| LegalizerHelper::LegalizeResult |
| LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) { |
| MIRBuilder.setInstr(MI); |
| |
| switch (MI.getOpcode()) { |
| default: |
| return UnableToLegalize; |
| case TargetOpcode::G_CTTZ: |
| case TargetOpcode::G_CTTZ_ZERO_UNDEF: |
| case TargetOpcode::G_CTLZ: |
| case TargetOpcode::G_CTLZ_ZERO_UNDEF: |
| case TargetOpcode::G_CTPOP: { |
| // First ZEXT the input. |
| auto MIBSrc = MIRBuilder.buildZExt(WideTy, MI.getOperand(1).getReg()); |
| LLT CurTy = MRI.getType(MI.getOperand(0).getReg()); |
| 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.buildInstr( |
| TargetOpcode::G_OR, WideTy, MIBSrc, |
| MIRBuilder.buildConstant(WideTy, TopBit.getSExtValue())); |
| } |
| // 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)); |
| } |
| auto &TII = *MI.getMF()->getSubtarget().getInstrInfo(); |
| // Make the original instruction a trunc now, and update it's source. |
| MI.setDesc(TII.get(TargetOpcode::G_TRUNC)); |
| MI.getOperand(1).setReg(MIBNewOp->getOperand(0).getReg()); |
| MIRBuilder.recordInsertion(&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 fine here, high bits |
| // don't affect the result) and then truncate the result back to the |
| // original type. |
| widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT); |
| widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ANYEXT); |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_SHL: |
| widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT); |
| // The "number of bits to shift" operand must preserve its value as an |
| // unsigned integer: |
| widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ZEXT); |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_SDIV: |
| case TargetOpcode::G_SREM: |
| widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_SEXT); |
| widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_SEXT); |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_ASHR: |
| widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_SEXT); |
| // The "number of bits to shift" operand must preserve its value as an |
| // unsigned integer: |
| widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ZEXT); |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_UDIV: |
| case TargetOpcode::G_UREM: |
| case TargetOpcode::G_LSHR: |
| widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ZEXT); |
| widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ZEXT); |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_SELECT: |
| if (TypeIdx != 0) |
| return UnableToLegalize; |
| // 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); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_FPTOSI: |
| case TargetOpcode::G_FPTOUI: |
| if (TypeIdx != 0) |
| return UnableToLegalize; |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_SITOFP: |
| if (TypeIdx != 1) |
| return UnableToLegalize; |
| widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_SEXT); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_UITOFP: |
| if (TypeIdx != 1) |
| return UnableToLegalize; |
| widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ZEXT); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_INSERT: |
| if (TypeIdx != 0) |
| return UnableToLegalize; |
| widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT); |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_LOAD: |
| // For some types like i24, we might try to widen to i32. To properly handle |
| // this we should be using a dedicated extending load, until then avoid |
| // trying to legalize. |
| if (alignTo(MRI.getType(MI.getOperand(0).getReg()).getSizeInBits(), 8) != |
| WideTy.getSizeInBits()) |
| return UnableToLegalize; |
| LLVM_FALLTHROUGH; |
| case TargetOpcode::G_SEXTLOAD: |
| case TargetOpcode::G_ZEXTLOAD: |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_STORE: { |
| if (MRI.getType(MI.getOperand(0).getReg()) != LLT::scalar(1) || |
| WideTy != LLT::scalar(8)) |
| return UnableToLegalize; |
| |
| widenScalarSrc(MI, WideTy, 0, TargetOpcode::G_ZEXT); |
| MIRBuilder.recordInsertion(&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()); |
| SrcMO.setCImm(ConstantInt::get(Ctx, Val)); |
| |
| widenScalarDst(MI, WideTy); |
| MIRBuilder.recordInsertion(&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::rmTowardZero, &LosesInfo); |
| break; |
| case 64: |
| Val.convert(APFloat::IEEEdouble(), APFloat::rmTowardZero, &LosesInfo); |
| break; |
| default: |
| llvm_unreachable("Unhandled fp widen type"); |
| } |
| SrcMO.setFPImm(ConstantFP::get(Ctx, Val)); |
| |
| widenScalarDst(MI, WideTy, 0, TargetOpcode::G_FPTRUNC); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| } |
| case TargetOpcode::G_BRCOND: |
| widenScalarSrc(MI, WideTy, 0, TargetOpcode::G_ANYEXT); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_FCMP: |
| if (TypeIdx == 0) |
| widenScalarDst(MI, WideTy); |
| else { |
| widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_FPEXT); |
| widenScalarSrc(MI, WideTy, 3, TargetOpcode::G_FPEXT); |
| } |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_ICMP: |
| 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); |
| } |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_GEP: |
| assert(TypeIdx == 1 && "unable to legalize pointer of GEP"); |
| widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_SEXT); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| |
| case TargetOpcode::G_PHI: { |
| assert(TypeIdx == 0 && "Expecting only Idx 0"); |
| |
| 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); |
| MIRBuilder.recordInsertion(&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); |
| MIRBuilder.buildInstr(TargetOpcode::G_FSUB) |
| .addDef(Res) |
| .addUse(Zero->getOperand(0).getReg()) |
| .addUse(MI.getOperand(1).getReg()); |
| 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) |
| .addDef(Res) |
| .addUse(LHS) |
| .addUse(Neg); |
| 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.getSize() /* in bytes */ * 8)); |
| 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); |
| } |
| } |
| |
| LegalizerHelper::LegalizeResult |
| LegalizerHelper::fewerElementsVector(MachineInstr &MI, unsigned TypeIdx, |
| LLT NarrowTy) { |
| // FIXME: Don't know how to handle secondary types yet. |
| if (TypeIdx != 0) |
| return UnableToLegalize; |
| switch (MI.getOpcode()) { |
| default: |
| return UnableToLegalize; |
| case TargetOpcode::G_ADD: { |
| 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; |
| |
| MIRBuilder.setInstr(MI); |
| |
| SmallVector<unsigned, 2> Src1Regs, Src2Regs, DstRegs; |
| extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, Src1Regs); |
| extractParts(MI.getOperand(2).getReg(), NarrowTy, NumParts, Src2Regs); |
| |
| for (int i = 0; i < NumParts; ++i) { |
| unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy); |
| MIRBuilder.buildAdd(DstReg, Src1Regs[i], Src2Regs[i]); |
| DstRegs.push_back(DstReg); |
| } |
| |
| MIRBuilder.buildMerge(DstReg, DstRegs); |
| 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 isLegalOrCustom = [this](const LegalityQuery &Q) { |
| auto QAction = LI.getAction(Q).Action; |
| return QAction == Legal || QAction == Custom; |
| }; |
| switch (Opc) { |
| default: |
| return UnableToLegalize; |
| case TargetOpcode::G_CTLZ_ZERO_UNDEF: { |
| // This trivially expands to CTLZ. |
| MI.setDesc(TII.get(TargetOpcode::G_CTLZ)); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| } |
| case TargetOpcode::G_CTLZ: { |
| unsigned SrcReg = MI.getOperand(1).getReg(); |
| unsigned Len = Ty.getSizeInBits(); |
| if (isLegalOrCustom({TargetOpcode::G_CTLZ_ZERO_UNDEF, {Ty}})) { |
| // If CTLZ_ZERO_UNDEF is legal or custom, emit that and a select with |
| // 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. |
| MI.setDesc(TII.get(TargetOpcode::G_CTTZ)); |
| MIRBuilder.recordInsertion(&MI); |
| return Legalized; |
| } |
| case TargetOpcode::G_CTTZ: { |
| unsigned SrcReg = MI.getOperand(1).getReg(); |
| unsigned Len = Ty.getSizeInBits(); |
| if (isLegalOrCustom({TargetOpcode::G_CTTZ_ZERO_UNDEF, {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 (!isLegalOrCustom({TargetOpcode::G_CTPOP, {Ty}}) && |
| isLegalOrCustom({TargetOpcode::G_CTLZ, {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; |
| } |
| } |
| } |