| //===- HexagonTargetTransformInfo.cpp - Hexagon specific TTI pass ---------===// |
| // |
| // 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 a TargetTransformInfo analysis pass specific to the |
| /// Hexagon target machine. It uses the target's detailed information to provide |
| /// more precise answers to certain TTI queries, while letting the target |
| /// independent and default TTI implementations handle the rest. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #include "HexagonTargetTransformInfo.h" |
| #include "HexagonSubtarget.h" |
| #include "llvm/Analysis/TargetTransformInfo.h" |
| #include "llvm/CodeGen/ValueTypes.h" |
| #include "llvm/IR/InstrTypes.h" |
| #include "llvm/IR/Instructions.h" |
| #include "llvm/IR/User.h" |
| #include "llvm/Support/Casting.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Transforms/Utils/UnrollLoop.h" |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "hexagontti" |
| |
| static cl::opt<bool> HexagonAutoHVX("hexagon-autohvx", cl::init(false), |
| cl::Hidden, cl::desc("Enable loop vectorizer for HVX")); |
| |
| static cl::opt<bool> EmitLookupTables("hexagon-emit-lookup-tables", |
| cl::init(true), cl::Hidden, |
| cl::desc("Control lookup table emission on Hexagon target")); |
| |
| // Constant "cost factor" to make floating point operations more expensive |
| // in terms of vectorization cost. This isn't the best way, but it should |
| // do. Ultimately, the cost should use cycles. |
| static const unsigned FloatFactor = 4; |
| |
| bool HexagonTTIImpl::useHVX() const { |
| return ST.useHVXOps() && HexagonAutoHVX; |
| } |
| |
| bool HexagonTTIImpl::isTypeForHVX(Type *VecTy) const { |
| assert(VecTy->isVectorTy()); |
| if (cast<VectorType>(VecTy)->isScalable()) |
| return false; |
| // Avoid types like <2 x i32*>. |
| if (!cast<VectorType>(VecTy)->getElementType()->isIntegerTy()) |
| return false; |
| EVT VecVT = EVT::getEVT(VecTy); |
| if (!VecVT.isSimple() || VecVT.getSizeInBits() <= 64) |
| return false; |
| if (ST.isHVXVectorType(VecVT.getSimpleVT())) |
| return true; |
| auto Action = TLI.getPreferredVectorAction(VecVT.getSimpleVT()); |
| return Action == TargetLoweringBase::TypeWidenVector; |
| } |
| |
| unsigned HexagonTTIImpl::getTypeNumElements(Type *Ty) const { |
| if (Ty->isVectorTy()) |
| return Ty->getVectorNumElements(); |
| assert((Ty->isIntegerTy() || Ty->isFloatingPointTy()) && |
| "Expecting scalar type"); |
| return 1; |
| } |
| |
| TargetTransformInfo::PopcntSupportKind |
| HexagonTTIImpl::getPopcntSupport(unsigned IntTyWidthInBit) const { |
| // Return fast hardware support as every input < 64 bits will be promoted |
| // to 64 bits. |
| return TargetTransformInfo::PSK_FastHardware; |
| } |
| |
| // The Hexagon target can unroll loops with run-time trip counts. |
| void HexagonTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE, |
| TTI::UnrollingPreferences &UP) { |
| UP.Runtime = UP.Partial = true; |
| // Only try to peel innermost loops with small runtime trip counts. |
| if (L && L->empty() && canPeel(L) && |
| SE.getSmallConstantTripCount(L) == 0 && |
| SE.getSmallConstantMaxTripCount(L) > 0 && |
| SE.getSmallConstantMaxTripCount(L) <= 5) { |
| UP.PeelCount = 2; |
| } |
| } |
| |
| bool HexagonTTIImpl::shouldFavorPostInc() const { |
| return true; |
| } |
| |
| /// --- Vector TTI begin --- |
| |
| unsigned HexagonTTIImpl::getNumberOfRegisters(bool Vector) const { |
| if (Vector) |
| return useHVX() ? 32 : 0; |
| return 32; |
| } |
| |
| unsigned HexagonTTIImpl::getMaxInterleaveFactor(unsigned VF) { |
| return useHVX() ? 2 : 0; |
| } |
| |
| unsigned HexagonTTIImpl::getRegisterBitWidth(bool Vector) const { |
| return Vector ? getMinVectorRegisterBitWidth() : 32; |
| } |
| |
| unsigned HexagonTTIImpl::getMinVectorRegisterBitWidth() const { |
| return useHVX() ? ST.getVectorLength()*8 : 0; |
| } |
| |
| unsigned HexagonTTIImpl::getMinimumVF(unsigned ElemWidth) const { |
| return (8 * ST.getVectorLength()) / ElemWidth; |
| } |
| |
| unsigned HexagonTTIImpl::getScalarizationOverhead(Type *Ty, bool Insert, |
| bool Extract) { |
| return BaseT::getScalarizationOverhead(Ty, Insert, Extract); |
| } |
| |
| unsigned HexagonTTIImpl::getOperandsScalarizationOverhead( |
| ArrayRef<const Value*> Args, unsigned VF) { |
| return BaseT::getOperandsScalarizationOverhead(Args, VF); |
| } |
| |
| unsigned HexagonTTIImpl::getCallInstrCost(Function *F, Type *RetTy, |
| ArrayRef<Type*> Tys) { |
| return BaseT::getCallInstrCost(F, RetTy, Tys); |
| } |
| |
| unsigned HexagonTTIImpl::getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy, |
| ArrayRef<Value*> Args, FastMathFlags FMF, unsigned VF) { |
| return BaseT::getIntrinsicInstrCost(ID, RetTy, Args, FMF, VF); |
| } |
| |
| unsigned HexagonTTIImpl::getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy, |
| ArrayRef<Type*> Tys, FastMathFlags FMF, |
| unsigned ScalarizationCostPassed) { |
| if (ID == Intrinsic::bswap) { |
| std::pair<int, MVT> LT = TLI.getTypeLegalizationCost(DL, RetTy); |
| return LT.first + 2; |
| } |
| return BaseT::getIntrinsicInstrCost(ID, RetTy, Tys, FMF, |
| ScalarizationCostPassed); |
| } |
| |
| unsigned HexagonTTIImpl::getAddressComputationCost(Type *Tp, |
| ScalarEvolution *SE, const SCEV *S) { |
| return 0; |
| } |
| |
| unsigned HexagonTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src, |
| MaybeAlign Alignment, |
| unsigned AddressSpace, |
| const Instruction *I) { |
| assert(Opcode == Instruction::Load || Opcode == Instruction::Store); |
| if (Opcode == Instruction::Store) |
| return BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, I); |
| |
| if (Src->isVectorTy()) { |
| VectorType *VecTy = cast<VectorType>(Src); |
| unsigned VecWidth = VecTy->getBitWidth(); |
| if (useHVX() && isTypeForHVX(VecTy)) { |
| unsigned RegWidth = getRegisterBitWidth(true); |
| assert(RegWidth && "Non-zero vector register width expected"); |
| // Cost of HVX loads. |
| if (VecWidth % RegWidth == 0) |
| return VecWidth / RegWidth; |
| // Cost of constructing HVX vector from scalar loads |
| const Align RegAlign(RegWidth / 8); |
| if (!Alignment || *Alignment > RegAlign) |
| Alignment = RegAlign; |
| assert(Alignment); |
| unsigned AlignWidth = 8 * Alignment->value(); |
| unsigned NumLoads = alignTo(VecWidth, AlignWidth) / AlignWidth; |
| return 3 * NumLoads; |
| } |
| |
| // Non-HVX vectors. |
| // Add extra cost for floating point types. |
| unsigned Cost = |
| VecTy->getElementType()->isFloatingPointTy() ? FloatFactor : 1; |
| |
| // At this point unspecified alignment is considered as Align::None(). |
| const Align BoundAlignment = std::min(Alignment.valueOrOne(), Align(8)); |
| unsigned AlignWidth = 8 * BoundAlignment.value(); |
| unsigned NumLoads = alignTo(VecWidth, AlignWidth) / AlignWidth; |
| if (Alignment == Align(4) || Alignment == Align(8)) |
| return Cost * NumLoads; |
| // Loads of less than 32 bits will need extra inserts to compose a vector. |
| assert(BoundAlignment <= Align(8)); |
| unsigned LogA = Log2(BoundAlignment); |
| return (3 - LogA) * Cost * NumLoads; |
| } |
| |
| return BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, I); |
| } |
| |
| unsigned HexagonTTIImpl::getMaskedMemoryOpCost(unsigned Opcode, |
| Type *Src, unsigned Alignment, unsigned AddressSpace) { |
| return BaseT::getMaskedMemoryOpCost(Opcode, Src, Alignment, AddressSpace); |
| } |
| |
| unsigned HexagonTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, |
| int Index, Type *SubTp) { |
| return 1; |
| } |
| |
| unsigned HexagonTTIImpl::getGatherScatterOpCost(unsigned Opcode, Type *DataTy, |
| Value *Ptr, bool VariableMask, unsigned Alignment) { |
| return BaseT::getGatherScatterOpCost(Opcode, DataTy, Ptr, VariableMask, |
| Alignment); |
| } |
| |
| unsigned HexagonTTIImpl::getInterleavedMemoryOpCost(unsigned Opcode, |
| Type *VecTy, unsigned Factor, ArrayRef<unsigned> Indices, |
| unsigned Alignment, unsigned AddressSpace, bool UseMaskForCond, |
| bool UseMaskForGaps) { |
| if (Indices.size() != Factor || UseMaskForCond || UseMaskForGaps) |
| return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices, |
| Alignment, AddressSpace, |
| UseMaskForCond, UseMaskForGaps); |
| return getMemoryOpCost(Opcode, VecTy, MaybeAlign(Alignment), AddressSpace, |
| nullptr); |
| } |
| |
| unsigned HexagonTTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy, |
| Type *CondTy, const Instruction *I) { |
| if (ValTy->isVectorTy()) { |
| std::pair<int, MVT> LT = TLI.getTypeLegalizationCost(DL, ValTy); |
| if (Opcode == Instruction::FCmp) |
| return LT.first + FloatFactor * getTypeNumElements(ValTy); |
| } |
| return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, I); |
| } |
| |
| unsigned HexagonTTIImpl::getArithmeticInstrCost( |
| unsigned Opcode, Type *Ty, TTI::OperandValueKind Opd1Info, |
| TTI::OperandValueKind Opd2Info, TTI::OperandValueProperties Opd1PropInfo, |
| TTI::OperandValueProperties Opd2PropInfo, ArrayRef<const Value *> Args, |
| const Instruction *CxtI) { |
| if (Ty->isVectorTy()) { |
| std::pair<int, MVT> LT = TLI.getTypeLegalizationCost(DL, Ty); |
| if (LT.second.isFloatingPoint()) |
| return LT.first + FloatFactor * getTypeNumElements(Ty); |
| } |
| return BaseT::getArithmeticInstrCost(Opcode, Ty, Opd1Info, Opd2Info, |
| Opd1PropInfo, Opd2PropInfo, Args, CxtI); |
| } |
| |
| unsigned HexagonTTIImpl::getCastInstrCost(unsigned Opcode, Type *DstTy, |
| Type *SrcTy, const Instruction *I) { |
| if (SrcTy->isFPOrFPVectorTy() || DstTy->isFPOrFPVectorTy()) { |
| unsigned SrcN = SrcTy->isFPOrFPVectorTy() ? getTypeNumElements(SrcTy) : 0; |
| unsigned DstN = DstTy->isFPOrFPVectorTy() ? getTypeNumElements(DstTy) : 0; |
| |
| std::pair<int, MVT> SrcLT = TLI.getTypeLegalizationCost(DL, SrcTy); |
| std::pair<int, MVT> DstLT = TLI.getTypeLegalizationCost(DL, DstTy); |
| return std::max(SrcLT.first, DstLT.first) + FloatFactor * (SrcN + DstN); |
| } |
| return 1; |
| } |
| |
| unsigned HexagonTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val, |
| unsigned Index) { |
| Type *ElemTy = Val->isVectorTy() ? cast<VectorType>(Val)->getElementType() |
| : Val; |
| if (Opcode == Instruction::InsertElement) { |
| // Need two rotations for non-zero index. |
| unsigned Cost = (Index != 0) ? 2 : 0; |
| if (ElemTy->isIntegerTy(32)) |
| return Cost; |
| // If it's not a 32-bit value, there will need to be an extract. |
| return Cost + getVectorInstrCost(Instruction::ExtractElement, Val, Index); |
| } |
| |
| if (Opcode == Instruction::ExtractElement) |
| return 2; |
| |
| return 1; |
| } |
| |
| /// --- Vector TTI end --- |
| |
| unsigned HexagonTTIImpl::getPrefetchDistance() const { |
| return ST.getL1PrefetchDistance(); |
| } |
| |
| unsigned HexagonTTIImpl::getCacheLineSize() const { |
| return ST.getL1CacheLineSize(); |
| } |
| |
| int HexagonTTIImpl::getUserCost(const User *U, |
| ArrayRef<const Value *> Operands) { |
| auto isCastFoldedIntoLoad = [this](const CastInst *CI) -> bool { |
| if (!CI->isIntegerCast()) |
| return false; |
| // Only extensions from an integer type shorter than 32-bit to i32 |
| // can be folded into the load. |
| const DataLayout &DL = getDataLayout(); |
| unsigned SBW = DL.getTypeSizeInBits(CI->getSrcTy()); |
| unsigned DBW = DL.getTypeSizeInBits(CI->getDestTy()); |
| if (DBW != 32 || SBW >= DBW) |
| return false; |
| |
| const LoadInst *LI = dyn_cast<const LoadInst>(CI->getOperand(0)); |
| // Technically, this code could allow multiple uses of the load, and |
| // check if all the uses are the same extension operation, but this |
| // should be sufficient for most cases. |
| return LI && LI->hasOneUse(); |
| }; |
| |
| if (const CastInst *CI = dyn_cast<const CastInst>(U)) |
| if (isCastFoldedIntoLoad(CI)) |
| return TargetTransformInfo::TCC_Free; |
| return BaseT::getUserCost(U, Operands); |
| } |
| |
| bool HexagonTTIImpl::shouldBuildLookupTables() const { |
| return EmitLookupTables; |
| } |