forked from OSchip/llvm-project
312 lines
11 KiB
C++
312 lines
11 KiB
C++
//===- HexagonTargetTransformInfo.cpp - Hexagon specific TTI pass ---------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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/// \file
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/// This file implements a TargetTransformInfo analysis pass specific to the
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/// Hexagon target machine. It uses the target's detailed information to provide
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/// more precise answers to certain TTI queries, while letting the target
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/// independent and default TTI implementations handle the rest.
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///
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//===----------------------------------------------------------------------===//
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#include "HexagonTargetTransformInfo.h"
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#include "HexagonSubtarget.h"
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#include "llvm/Analysis/TargetTransformInfo.h"
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#include "llvm/CodeGen/ValueTypes.h"
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#include "llvm/IR/InstrTypes.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/User.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Transforms/Utils/UnrollLoop.h"
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using namespace llvm;
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#define DEBUG_TYPE "hexagontti"
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static cl::opt<bool> HexagonAutoHVX("hexagon-autohvx", cl::init(false),
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cl::Hidden, cl::desc("Enable loop vectorizer for HVX"));
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static cl::opt<bool> EmitLookupTables("hexagon-emit-lookup-tables",
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cl::init(true), cl::Hidden,
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cl::desc("Control lookup table emission on Hexagon target"));
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// Constant "cost factor" to make floating point operations more expensive
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// in terms of vectorization cost. This isn't the best way, but it should
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// do. Ultimately, the cost should use cycles.
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static const unsigned FloatFactor = 4;
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bool HexagonTTIImpl::useHVX() const {
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return ST.useHVXOps() && HexagonAutoHVX;
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}
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bool HexagonTTIImpl::isTypeForHVX(Type *VecTy) const {
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assert(VecTy->isVectorTy());
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// Avoid types like <2 x i32*>.
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if (!cast<VectorType>(VecTy)->getElementType()->isIntegerTy())
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return false;
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EVT VecVT = EVT::getEVT(VecTy);
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if (!VecVT.isSimple() || VecVT.getSizeInBits() <= 64)
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return false;
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if (ST.isHVXVectorType(VecVT.getSimpleVT()))
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return true;
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auto Action = TLI.getPreferredVectorAction(VecVT.getSimpleVT());
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return Action == TargetLoweringBase::TypeWidenVector;
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}
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unsigned HexagonTTIImpl::getTypeNumElements(Type *Ty) const {
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if (Ty->isVectorTy())
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return Ty->getVectorNumElements();
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assert((Ty->isIntegerTy() || Ty->isFloatingPointTy()) &&
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"Expecting scalar type");
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return 1;
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}
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TargetTransformInfo::PopcntSupportKind
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HexagonTTIImpl::getPopcntSupport(unsigned IntTyWidthInBit) const {
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// Return fast hardware support as every input < 64 bits will be promoted
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// to 64 bits.
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return TargetTransformInfo::PSK_FastHardware;
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}
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// The Hexagon target can unroll loops with run-time trip counts.
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void HexagonTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
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TTI::UnrollingPreferences &UP) {
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UP.Runtime = UP.Partial = true;
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// Only try to peel innermost loops with small runtime trip counts.
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if (L && L->empty() && canPeel(L) &&
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SE.getSmallConstantTripCount(L) == 0 &&
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SE.getSmallConstantMaxTripCount(L) > 0 &&
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SE.getSmallConstantMaxTripCount(L) <= 5) {
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UP.PeelCount = 2;
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}
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}
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bool HexagonTTIImpl::shouldFavorPostInc() const {
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return true;
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}
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/// --- Vector TTI begin ---
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unsigned HexagonTTIImpl::getNumberOfRegisters(bool Vector) const {
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if (Vector)
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return useHVX() ? 32 : 0;
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return 32;
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}
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unsigned HexagonTTIImpl::getMaxInterleaveFactor(unsigned VF) {
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return useHVX() ? 2 : 0;
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}
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unsigned HexagonTTIImpl::getRegisterBitWidth(bool Vector) const {
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return Vector ? getMinVectorRegisterBitWidth() : 32;
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}
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unsigned HexagonTTIImpl::getMinVectorRegisterBitWidth() const {
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return useHVX() ? ST.getVectorLength()*8 : 0;
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}
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unsigned HexagonTTIImpl::getMinimumVF(unsigned ElemWidth) const {
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return (8 * ST.getVectorLength()) / ElemWidth;
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}
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unsigned HexagonTTIImpl::getScalarizationOverhead(Type *Ty, bool Insert,
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bool Extract) {
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return BaseT::getScalarizationOverhead(Ty, Insert, Extract);
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}
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unsigned HexagonTTIImpl::getOperandsScalarizationOverhead(
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ArrayRef<const Value*> Args, unsigned VF) {
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return BaseT::getOperandsScalarizationOverhead(Args, VF);
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}
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unsigned HexagonTTIImpl::getCallInstrCost(Function *F, Type *RetTy,
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ArrayRef<Type*> Tys) {
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return BaseT::getCallInstrCost(F, RetTy, Tys);
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}
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unsigned HexagonTTIImpl::getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
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ArrayRef<Value*> Args, FastMathFlags FMF, unsigned VF) {
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return BaseT::getIntrinsicInstrCost(ID, RetTy, Args, FMF, VF);
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}
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unsigned HexagonTTIImpl::getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
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ArrayRef<Type*> Tys, FastMathFlags FMF,
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unsigned ScalarizationCostPassed) {
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if (ID == Intrinsic::bswap) {
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std::pair<int, MVT> LT = TLI.getTypeLegalizationCost(DL, RetTy);
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return LT.first + 2;
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}
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return BaseT::getIntrinsicInstrCost(ID, RetTy, Tys, FMF,
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ScalarizationCostPassed);
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}
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unsigned HexagonTTIImpl::getAddressComputationCost(Type *Tp,
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ScalarEvolution *SE, const SCEV *S) {
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return 0;
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}
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unsigned HexagonTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src,
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unsigned Alignment, unsigned AddressSpace, const Instruction *I) {
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assert(Opcode == Instruction::Load || Opcode == Instruction::Store);
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if (Opcode == Instruction::Store)
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return BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, I);
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if (Src->isVectorTy()) {
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VectorType *VecTy = cast<VectorType>(Src);
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unsigned VecWidth = VecTy->getBitWidth();
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if (useHVX() && isTypeForHVX(VecTy)) {
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unsigned RegWidth = getRegisterBitWidth(true);
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Alignment = std::min(Alignment, RegWidth/8);
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// Cost of HVX loads.
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if (VecWidth % RegWidth == 0)
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return VecWidth / RegWidth;
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// Cost of constructing HVX vector from scalar loads.
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unsigned AlignWidth = 8 * std::max(1u, Alignment);
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unsigned NumLoads = alignTo(VecWidth, AlignWidth) / AlignWidth;
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return 3*NumLoads;
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}
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// Non-HVX vectors.
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// Add extra cost for floating point types.
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unsigned Cost = VecTy->getElementType()->isFloatingPointTy() ? FloatFactor
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: 1;
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Alignment = std::min(Alignment, 8u);
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unsigned AlignWidth = 8 * std::max(1u, Alignment);
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unsigned NumLoads = alignTo(VecWidth, AlignWidth) / AlignWidth;
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if (Alignment == 4 || Alignment == 8)
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return Cost * NumLoads;
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// Loads of less than 32 bits will need extra inserts to compose a vector.
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unsigned LogA = Log2_32(Alignment);
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return (3 - LogA) * Cost * NumLoads;
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}
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return BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, I);
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}
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unsigned HexagonTTIImpl::getMaskedMemoryOpCost(unsigned Opcode,
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Type *Src, unsigned Alignment, unsigned AddressSpace) {
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return BaseT::getMaskedMemoryOpCost(Opcode, Src, Alignment, AddressSpace);
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}
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unsigned HexagonTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp,
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int Index, Type *SubTp) {
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return 1;
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}
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unsigned HexagonTTIImpl::getGatherScatterOpCost(unsigned Opcode, Type *DataTy,
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Value *Ptr, bool VariableMask, unsigned Alignment) {
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return BaseT::getGatherScatterOpCost(Opcode, DataTy, Ptr, VariableMask,
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Alignment);
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}
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unsigned HexagonTTIImpl::getInterleavedMemoryOpCost(unsigned Opcode,
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Type *VecTy, unsigned Factor, ArrayRef<unsigned> Indices,
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unsigned Alignment, unsigned AddressSpace, bool UseMaskForCond,
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bool UseMaskForGaps) {
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if (Indices.size() != Factor || UseMaskForCond || UseMaskForGaps)
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return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices,
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Alignment, AddressSpace,
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UseMaskForCond, UseMaskForGaps);
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return getMemoryOpCost(Opcode, VecTy, Alignment, AddressSpace, nullptr);
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}
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unsigned HexagonTTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
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Type *CondTy, const Instruction *I) {
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if (ValTy->isVectorTy()) {
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std::pair<int, MVT> LT = TLI.getTypeLegalizationCost(DL, ValTy);
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if (Opcode == Instruction::FCmp)
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return LT.first + FloatFactor * getTypeNumElements(ValTy);
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}
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return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, I);
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}
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unsigned HexagonTTIImpl::getArithmeticInstrCost(unsigned Opcode, Type *Ty,
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TTI::OperandValueKind Opd1Info, TTI::OperandValueKind Opd2Info,
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TTI::OperandValueProperties Opd1PropInfo,
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TTI::OperandValueProperties Opd2PropInfo, ArrayRef<const Value*> Args) {
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if (Ty->isVectorTy()) {
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std::pair<int, MVT> LT = TLI.getTypeLegalizationCost(DL, Ty);
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if (LT.second.isFloatingPoint())
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return LT.first + FloatFactor * getTypeNumElements(Ty);
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}
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return BaseT::getArithmeticInstrCost(Opcode, Ty, Opd1Info, Opd2Info,
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Opd1PropInfo, Opd2PropInfo, Args);
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}
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unsigned HexagonTTIImpl::getCastInstrCost(unsigned Opcode, Type *DstTy,
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Type *SrcTy, const Instruction *I) {
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if (SrcTy->isFPOrFPVectorTy() || DstTy->isFPOrFPVectorTy()) {
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unsigned SrcN = SrcTy->isFPOrFPVectorTy() ? getTypeNumElements(SrcTy) : 0;
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unsigned DstN = DstTy->isFPOrFPVectorTy() ? getTypeNumElements(DstTy) : 0;
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std::pair<int, MVT> SrcLT = TLI.getTypeLegalizationCost(DL, SrcTy);
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std::pair<int, MVT> DstLT = TLI.getTypeLegalizationCost(DL, DstTy);
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return std::max(SrcLT.first, DstLT.first) + FloatFactor * (SrcN + DstN);
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}
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return 1;
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}
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unsigned HexagonTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
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unsigned Index) {
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Type *ElemTy = Val->isVectorTy() ? cast<VectorType>(Val)->getElementType()
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: Val;
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if (Opcode == Instruction::InsertElement) {
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// Need two rotations for non-zero index.
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unsigned Cost = (Index != 0) ? 2 : 0;
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if (ElemTy->isIntegerTy(32))
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return Cost;
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// If it's not a 32-bit value, there will need to be an extract.
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return Cost + getVectorInstrCost(Instruction::ExtractElement, Val, Index);
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}
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if (Opcode == Instruction::ExtractElement)
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return 2;
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return 1;
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}
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/// --- Vector TTI end ---
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unsigned HexagonTTIImpl::getPrefetchDistance() const {
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return ST.getL1PrefetchDistance();
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}
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unsigned HexagonTTIImpl::getCacheLineSize() const {
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return ST.getL1CacheLineSize();
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}
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int HexagonTTIImpl::getUserCost(const User *U,
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ArrayRef<const Value *> Operands) {
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auto isCastFoldedIntoLoad = [this](const CastInst *CI) -> bool {
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if (!CI->isIntegerCast())
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return false;
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// Only extensions from an integer type shorter than 32-bit to i32
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// can be folded into the load.
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const DataLayout &DL = getDataLayout();
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unsigned SBW = DL.getTypeSizeInBits(CI->getSrcTy());
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unsigned DBW = DL.getTypeSizeInBits(CI->getDestTy());
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if (DBW != 32 || SBW >= DBW)
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return false;
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const LoadInst *LI = dyn_cast<const LoadInst>(CI->getOperand(0));
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// Technically, this code could allow multiple uses of the load, and
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// check if all the uses are the same extension operation, but this
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// should be sufficient for most cases.
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return LI && LI->hasOneUse();
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};
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if (const CastInst *CI = dyn_cast<const CastInst>(U))
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if (isCastFoldedIntoLoad(CI))
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return TargetTransformInfo::TCC_Free;
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return BaseT::getUserCost(U, Operands);
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}
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bool HexagonTTIImpl::shouldBuildLookupTables() const {
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return EmitLookupTables;
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}
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