//===-- X86TargetTransformInfo.cpp - X86 specific TTI pass ----------------===// // // 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 a TargetTransformInfo analysis pass specific to the /// X86 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. /// //===----------------------------------------------------------------------===// #define DEBUG_TYPE "x86tti" #include "X86.h" #include "X86TargetMachine.h" #include "llvm/Analysis/TargetTransformInfo.h" #include "llvm/Support/Debug.h" #include "llvm/Target/TargetLowering.h" #include "llvm/Target/CostTable.h" using namespace llvm; // Declare the pass initialization routine locally as target-specific passes // don't havve a target-wide initialization entry point, and so we rely on the // pass constructor initialization. namespace llvm { void initializeX86TTIPass(PassRegistry &); } namespace { class X86TTI : public ImmutablePass, public TargetTransformInfo { const X86Subtarget *ST; const X86TargetLowering *TLI; /// Estimate the overhead of scalarizing an instruction. Insert and Extract /// are set if the result needs to be inserted and/or extracted from vectors. unsigned getScalarizationOverhead(Type *Ty, bool Insert, bool Extract) const; public: X86TTI() : ImmutablePass(ID), ST(0), TLI(0) { llvm_unreachable("This pass cannot be directly constructed"); } X86TTI(const X86TargetMachine *TM) : ImmutablePass(ID), ST(TM->getSubtargetImpl()), TLI(TM->getTargetLowering()) { initializeX86TTIPass(*PassRegistry::getPassRegistry()); } virtual void initializePass() { pushTTIStack(this); } virtual void finalizePass() { popTTIStack(); } virtual void getAnalysisUsage(AnalysisUsage &AU) const { TargetTransformInfo::getAnalysisUsage(AU); } /// Pass identification. static char ID; /// Provide necessary pointer adjustments for the two base classes. virtual void *getAdjustedAnalysisPointer(const void *ID) { if (ID == &TargetTransformInfo::ID) return (TargetTransformInfo*)this; return this; } /// \name Scalar TTI Implementations /// @{ virtual PopcntSupportKind getPopcntSupport(unsigned TyWidth) const; /// @} /// \name Vector TTI Implementations /// @{ virtual unsigned getNumberOfRegisters(bool Vector) const; virtual unsigned getRegisterBitWidth(bool Vector) const; virtual unsigned getMaximumUnrollFactor() const; virtual unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueKind, OperandValueKind) const; virtual unsigned getShuffleCost(ShuffleKind Kind, Type *Tp, int Index, Type *SubTp) const; virtual unsigned getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) const; virtual unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy) const; virtual unsigned getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) const; virtual unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment, unsigned AddressSpace) const; virtual unsigned getAddressComputationCost(Type *PtrTy, bool IsComplex) const; virtual unsigned getReductionCost(unsigned Opcode, Type *Ty, bool IsPairwiseForm) const; /// @} }; } // end anonymous namespace INITIALIZE_AG_PASS(X86TTI, TargetTransformInfo, "x86tti", "X86 Target Transform Info", true, true, false) char X86TTI::ID = 0; ImmutablePass * llvm::createX86TargetTransformInfoPass(const X86TargetMachine *TM) { return new X86TTI(TM); } //===----------------------------------------------------------------------===// // // X86 cost model. // //===----------------------------------------------------------------------===// X86TTI::PopcntSupportKind X86TTI::getPopcntSupport(unsigned TyWidth) const { assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2"); // TODO: Currently the __builtin_popcount() implementation using SSE3 // instructions is inefficient. Once the problem is fixed, we should // call ST->hasSSE3() instead of ST->hasPOPCNT(). return ST->hasPOPCNT() ? PSK_FastHardware : PSK_Software; } unsigned X86TTI::getNumberOfRegisters(bool Vector) const { if (Vector && !ST->hasSSE1()) return 0; if (ST->is64Bit()) return 16; return 8; } unsigned X86TTI::getRegisterBitWidth(bool Vector) const { if (Vector) { if (ST->hasAVX()) return 256; if (ST->hasSSE1()) return 128; return 0; } if (ST->is64Bit()) return 64; return 32; } unsigned X86TTI::getMaximumUnrollFactor() const { if (ST->isAtom()) return 1; // Sandybridge and Haswell have multiple execution ports and pipelined // vector units. if (ST->hasAVX()) return 4; return 2; } unsigned X86TTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueKind Op1Info, OperandValueKind Op2Info) const { // Legalize the type. std::pair LT = TLI->getTypeLegalizationCost(Ty); int ISD = TLI->InstructionOpcodeToISD(Opcode); assert(ISD && "Invalid opcode"); static const CostTblEntry AVX2CostTable[] = { // Shifts on v4i64/v8i32 on AVX2 is legal even though we declare to // customize them to detect the cases where shift amount is a scalar one. { ISD::SHL, MVT::v4i32, 1 }, { ISD::SRL, MVT::v4i32, 1 }, { ISD::SRA, MVT::v4i32, 1 }, { ISD::SHL, MVT::v8i32, 1 }, { ISD::SRL, MVT::v8i32, 1 }, { ISD::SRA, MVT::v8i32, 1 }, { ISD::SHL, MVT::v2i64, 1 }, { ISD::SRL, MVT::v2i64, 1 }, { ISD::SHL, MVT::v4i64, 1 }, { ISD::SRL, MVT::v4i64, 1 }, { ISD::SHL, MVT::v32i8, 42 }, // cmpeqb sequence. { ISD::SHL, MVT::v16i16, 16*10 }, // Scalarized. { ISD::SRL, MVT::v32i8, 32*10 }, // Scalarized. { ISD::SRL, MVT::v16i16, 8*10 }, // Scalarized. { ISD::SRA, MVT::v32i8, 32*10 }, // Scalarized. { ISD::SRA, MVT::v16i16, 16*10 }, // Scalarized. { ISD::SRA, MVT::v4i64, 4*10 }, // Scalarized. // Vectorizing division is a bad idea. See the SSE2 table for more comments. { ISD::SDIV, MVT::v32i8, 32*20 }, { ISD::SDIV, MVT::v16i16, 16*20 }, { ISD::SDIV, MVT::v8i32, 8*20 }, { ISD::SDIV, MVT::v4i64, 4*20 }, { ISD::UDIV, MVT::v32i8, 32*20 }, { ISD::UDIV, MVT::v16i16, 16*20 }, { ISD::UDIV, MVT::v8i32, 8*20 }, { ISD::UDIV, MVT::v4i64, 4*20 }, }; // Look for AVX2 lowering tricks. if (ST->hasAVX2()) { int Idx = CostTableLookup(AVX2CostTable, ISD, LT.second); if (Idx != -1) return LT.first * AVX2CostTable[Idx].Cost; } static const CostTblEntry SSE2UniformConstCostTable[] = { // We don't correctly identify costs of casts because they are marked as // custom. // Constant splats are cheaper for the following instructions. { ISD::SHL, MVT::v16i8, 1 }, // psllw. { ISD::SHL, MVT::v8i16, 1 }, // psllw. { ISD::SHL, MVT::v4i32, 1 }, // pslld { ISD::SHL, MVT::v2i64, 1 }, // psllq. { ISD::SRL, MVT::v16i8, 1 }, // psrlw. { ISD::SRL, MVT::v8i16, 1 }, // psrlw. { ISD::SRL, MVT::v4i32, 1 }, // psrld. { ISD::SRL, MVT::v2i64, 1 }, // psrlq. { ISD::SRA, MVT::v16i8, 4 }, // psrlw, pand, pxor, psubb. { ISD::SRA, MVT::v8i16, 1 }, // psraw. { ISD::SRA, MVT::v4i32, 1 }, // psrad. }; if (Op2Info == TargetTransformInfo::OK_UniformConstantValue && ST->hasSSE2()) { int Idx = CostTableLookup(SSE2UniformConstCostTable, ISD, LT.second); if (Idx != -1) return LT.first * SSE2UniformConstCostTable[Idx].Cost; } static const CostTblEntry SSE2CostTable[] = { // We don't correctly identify costs of casts because they are marked as // custom. // For some cases, where the shift amount is a scalar we would be able // to generate better code. Unfortunately, when this is the case the value // (the splat) will get hoisted out of the loop, thereby making it invisible // to ISel. The cost model must return worst case assumptions because it is // used for vectorization and we don't want to make vectorized code worse // than scalar code. { ISD::SHL, MVT::v16i8, 30 }, // cmpeqb sequence. { ISD::SHL, MVT::v8i16, 8*10 }, // Scalarized. { ISD::SHL, MVT::v4i32, 2*5 }, // We optimized this using mul. { ISD::SHL, MVT::v2i64, 2*10 }, // Scalarized. { ISD::SRL, MVT::v16i8, 16*10 }, // Scalarized. { ISD::SRL, MVT::v8i16, 8*10 }, // Scalarized. { ISD::SRL, MVT::v4i32, 4*10 }, // Scalarized. { ISD::SRL, MVT::v2i64, 2*10 }, // Scalarized. { ISD::SRA, MVT::v16i8, 16*10 }, // Scalarized. { ISD::SRA, MVT::v8i16, 8*10 }, // Scalarized. { ISD::SRA, MVT::v4i32, 4*10 }, // Scalarized. { ISD::SRA, MVT::v2i64, 2*10 }, // Scalarized. // It is not a good idea to vectorize division. We have to scalarize it and // in the process we will often end up having to spilling regular // registers. The overhead of division is going to dominate most kernels // anyways so try hard to prevent vectorization of division - it is // generally a bad idea. Assume somewhat arbitrarily that we have to be able // to hide "20 cycles" for each lane. { ISD::SDIV, MVT::v16i8, 16*20 }, { ISD::SDIV, MVT::v8i16, 8*20 }, { ISD::SDIV, MVT::v4i32, 4*20 }, { ISD::SDIV, MVT::v2i64, 2*20 }, { ISD::UDIV, MVT::v16i8, 16*20 }, { ISD::UDIV, MVT::v8i16, 8*20 }, { ISD::UDIV, MVT::v4i32, 4*20 }, { ISD::UDIV, MVT::v2i64, 2*20 }, }; if (ST->hasSSE2()) { int Idx = CostTableLookup(SSE2CostTable, ISD, LT.second); if (Idx != -1) return LT.first * SSE2CostTable[Idx].Cost; } static const CostTblEntry AVX1CostTable[] = { // We don't have to scalarize unsupported ops. We can issue two half-sized // operations and we only need to extract the upper YMM half. // Two ops + 1 extract + 1 insert = 4. { ISD::MUL, MVT::v8i32, 4 }, { ISD::SUB, MVT::v8i32, 4 }, { ISD::ADD, MVT::v8i32, 4 }, { ISD::SUB, MVT::v4i64, 4 }, { ISD::ADD, MVT::v4i64, 4 }, // A v4i64 multiply is custom lowered as two split v2i64 vectors that then // are lowered as a series of long multiplies(3), shifts(4) and adds(2) // Because we believe v4i64 to be a legal type, we must also include the // split factor of two in the cost table. Therefore, the cost here is 18 // instead of 9. { ISD::MUL, MVT::v4i64, 18 }, }; // Look for AVX1 lowering tricks. if (ST->hasAVX() && !ST->hasAVX2()) { int Idx = CostTableLookup(AVX1CostTable, ISD, LT.second); if (Idx != -1) return LT.first * AVX1CostTable[Idx].Cost; } // Custom lowering of vectors. static const CostTblEntry CustomLowered[] = { // A v2i64/v4i64 and multiply is custom lowered as a series of long // multiplies(3), shifts(4) and adds(2). { ISD::MUL, MVT::v2i64, 9 }, { ISD::MUL, MVT::v4i64, 9 }, }; int Idx = CostTableLookup(CustomLowered, ISD, LT.second); if (Idx != -1) return LT.first * CustomLowered[Idx].Cost; // Special lowering of v4i32 mul on sse2, sse3: Lower v4i32 mul as 2x shuffle, // 2x pmuludq, 2x shuffle. if (ISD == ISD::MUL && LT.second == MVT::v4i32 && ST->hasSSE2() && !ST->hasSSE41()) return 6; // Fallback to the default implementation. return TargetTransformInfo::getArithmeticInstrCost(Opcode, Ty, Op1Info, Op2Info); } unsigned X86TTI::getShuffleCost(ShuffleKind Kind, Type *Tp, int Index, Type *SubTp) const { // We only estimate the cost of reverse shuffles. if (Kind != SK_Reverse) return TargetTransformInfo::getShuffleCost(Kind, Tp, Index, SubTp); std::pair LT = TLI->getTypeLegalizationCost(Tp); unsigned Cost = 1; if (LT.second.getSizeInBits() > 128) Cost = 3; // Extract + insert + copy. // Multiple by the number of parts. return Cost * LT.first; } unsigned X86TTI::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) const { int ISD = TLI->InstructionOpcodeToISD(Opcode); assert(ISD && "Invalid opcode"); std::pair LTSrc = TLI->getTypeLegalizationCost(Src); std::pair LTDest = TLI->getTypeLegalizationCost(Dst); static const TypeConversionCostTblEntry SSE2ConvTbl[] = { // These are somewhat magic numbers justified by looking at the output of // Intel's IACA, running some kernels and making sure when we take // legalization into account the throughput will be overestimated. { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i64, 2*10 }, { ISD::UINT_TO_FP, MVT::v2f64, MVT::v4i32, 4*10 }, { ISD::UINT_TO_FP, MVT::v2f64, MVT::v8i16, 8*10 }, { ISD::UINT_TO_FP, MVT::v2f64, MVT::v16i8, 16*10 }, { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i64, 2*10 }, { ISD::SINT_TO_FP, MVT::v2f64, MVT::v4i32, 4*10 }, { ISD::SINT_TO_FP, MVT::v2f64, MVT::v8i16, 8*10 }, { ISD::SINT_TO_FP, MVT::v2f64, MVT::v16i8, 16*10 }, // There are faster sequences for float conversions. { ISD::UINT_TO_FP, MVT::v4f32, MVT::v2i64, 15 }, { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i32, 15 }, { ISD::UINT_TO_FP, MVT::v4f32, MVT::v8i16, 15 }, { ISD::UINT_TO_FP, MVT::v4f32, MVT::v16i8, 8 }, { ISD::SINT_TO_FP, MVT::v4f32, MVT::v2i64, 15 }, { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i32, 15 }, { ISD::SINT_TO_FP, MVT::v4f32, MVT::v8i16, 15 }, { ISD::SINT_TO_FP, MVT::v4f32, MVT::v16i8, 8 }, }; if (ST->hasSSE2() && !ST->hasAVX()) { int Idx = ConvertCostTableLookup(SSE2ConvTbl, ISD, LTDest.second, LTSrc.second); if (Idx != -1) return LTSrc.first * SSE2ConvTbl[Idx].Cost; } EVT SrcTy = TLI->getValueType(Src); EVT DstTy = TLI->getValueType(Dst); // The function getSimpleVT only handles simple value types. if (!SrcTy.isSimple() || !DstTy.isSimple()) return TargetTransformInfo::getCastInstrCost(Opcode, Dst, Src); static const TypeConversionCostTblEntry AVXConversionTbl[] = { { ISD::SIGN_EXTEND, MVT::v16i16, MVT::v16i8, 1 }, { ISD::ZERO_EXTEND, MVT::v16i16, MVT::v16i8, 1 }, { ISD::SIGN_EXTEND, MVT::v8i32, MVT::v8i16, 1 }, { ISD::ZERO_EXTEND, MVT::v8i32, MVT::v8i16, 1 }, { ISD::SIGN_EXTEND, MVT::v4i64, MVT::v4i32, 1 }, { ISD::ZERO_EXTEND, MVT::v4i64, MVT::v4i32, 1 }, { ISD::TRUNCATE, MVT::v4i32, MVT::v4i64, 1 }, { ISD::TRUNCATE, MVT::v8i16, MVT::v8i32, 1 }, { ISD::TRUNCATE, MVT::v16i8, MVT::v16i16, 2 }, { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i1, 8 }, { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i8, 8 }, { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i16, 5 }, { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i32, 1 }, { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i1, 3 }, { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i8, 3 }, { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i16, 3 }, { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 }, { ISD::SINT_TO_FP, MVT::v4f64, MVT::v4i1, 3 }, { ISD::SINT_TO_FP, MVT::v4f64, MVT::v4i8, 3 }, { ISD::SINT_TO_FP, MVT::v4f64, MVT::v4i16, 3 }, { ISD::SINT_TO_FP, MVT::v4f64, MVT::v4i32, 1 }, { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i1, 6 }, { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i8, 5 }, { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i16, 5 }, { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i32, 9 }, { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i1, 7 }, { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i8, 2 }, { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 }, { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i32, 6 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i1, 7 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i8, 2 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i16, 2 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i32, 6 }, { ISD::FP_TO_SINT, MVT::v8i8, MVT::v8f32, 1 }, { ISD::FP_TO_SINT, MVT::v4i8, MVT::v4f32, 1 }, { ISD::ZERO_EXTEND, MVT::v8i32, MVT::v8i1, 6 }, { ISD::SIGN_EXTEND, MVT::v8i32, MVT::v8i1, 9 }, { ISD::SIGN_EXTEND, MVT::v4i64, MVT::v4i1, 8 }, { ISD::SIGN_EXTEND, MVT::v4i64, MVT::v4i8, 6 }, { ISD::SIGN_EXTEND, MVT::v4i64, MVT::v4i16, 6 }, { ISD::TRUNCATE, MVT::v8i32, MVT::v8i64, 3 }, }; if (ST->hasAVX()) { int Idx = ConvertCostTableLookup(AVXConversionTbl, ISD, DstTy.getSimpleVT(), SrcTy.getSimpleVT()); if (Idx != -1) return AVXConversionTbl[Idx].Cost; } return TargetTransformInfo::getCastInstrCost(Opcode, Dst, Src); } unsigned X86TTI::getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy) const { // Legalize the type. std::pair LT = TLI->getTypeLegalizationCost(ValTy); MVT MTy = LT.second; int ISD = TLI->InstructionOpcodeToISD(Opcode); assert(ISD && "Invalid opcode"); static const CostTblEntry SSE42CostTbl[] = { { ISD::SETCC, MVT::v2f64, 1 }, { ISD::SETCC, MVT::v4f32, 1 }, { ISD::SETCC, MVT::v2i64, 1 }, { ISD::SETCC, MVT::v4i32, 1 }, { ISD::SETCC, MVT::v8i16, 1 }, { ISD::SETCC, MVT::v16i8, 1 }, }; static const CostTblEntry AVX1CostTbl[] = { { ISD::SETCC, MVT::v4f64, 1 }, { ISD::SETCC, MVT::v8f32, 1 }, // AVX1 does not support 8-wide integer compare. { ISD::SETCC, MVT::v4i64, 4 }, { ISD::SETCC, MVT::v8i32, 4 }, { ISD::SETCC, MVT::v16i16, 4 }, { ISD::SETCC, MVT::v32i8, 4 }, }; static const CostTblEntry AVX2CostTbl[] = { { ISD::SETCC, MVT::v4i64, 1 }, { ISD::SETCC, MVT::v8i32, 1 }, { ISD::SETCC, MVT::v16i16, 1 }, { ISD::SETCC, MVT::v32i8, 1 }, }; if (ST->hasAVX2()) { int Idx = CostTableLookup(AVX2CostTbl, ISD, MTy); if (Idx != -1) return LT.first * AVX2CostTbl[Idx].Cost; } if (ST->hasAVX()) { int Idx = CostTableLookup(AVX1CostTbl, ISD, MTy); if (Idx != -1) return LT.first * AVX1CostTbl[Idx].Cost; } if (ST->hasSSE42()) { int Idx = CostTableLookup(SSE42CostTbl, ISD, MTy); if (Idx != -1) return LT.first * SSE42CostTbl[Idx].Cost; } return TargetTransformInfo::getCmpSelInstrCost(Opcode, ValTy, CondTy); } unsigned X86TTI::getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) const { assert(Val->isVectorTy() && "This must be a vector type"); if (Index != -1U) { // Legalize the type. std::pair LT = TLI->getTypeLegalizationCost(Val); // This type is legalized to a scalar type. if (!LT.second.isVector()) return 0; // The type may be split. Normalize the index to the new type. unsigned Width = LT.second.getVectorNumElements(); Index = Index % Width; // Floating point scalars are already located in index #0. if (Val->getScalarType()->isFloatingPointTy() && Index == 0) return 0; } return TargetTransformInfo::getVectorInstrCost(Opcode, Val, Index); } unsigned X86TTI::getScalarizationOverhead(Type *Ty, bool Insert, bool Extract) const { assert (Ty->isVectorTy() && "Can only scalarize vectors"); unsigned Cost = 0; for (int i = 0, e = Ty->getVectorNumElements(); i < e; ++i) { if (Insert) Cost += TopTTI->getVectorInstrCost(Instruction::InsertElement, Ty, i); if (Extract) Cost += TopTTI->getVectorInstrCost(Instruction::ExtractElement, Ty, i); } return Cost; } unsigned X86TTI::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment, unsigned AddressSpace) const { // Handle non power of two vectors such as <3 x float> if (VectorType *VTy = dyn_cast(Src)) { unsigned NumElem = VTy->getVectorNumElements(); // Handle a few common cases: // <3 x float> if (NumElem == 3 && VTy->getScalarSizeInBits() == 32) // Cost = 64 bit store + extract + 32 bit store. return 3; // <3 x double> if (NumElem == 3 && VTy->getScalarSizeInBits() == 64) // Cost = 128 bit store + unpack + 64 bit store. return 3; // Assume that all other non power-of-two numbers are scalarized. if (!isPowerOf2_32(NumElem)) { unsigned Cost = TargetTransformInfo::getMemoryOpCost(Opcode, VTy->getScalarType(), Alignment, AddressSpace); unsigned SplitCost = getScalarizationOverhead(Src, Opcode == Instruction::Load, Opcode==Instruction::Store); return NumElem * Cost + SplitCost; } } // Legalize the type. std::pair LT = TLI->getTypeLegalizationCost(Src); assert((Opcode == Instruction::Load || Opcode == Instruction::Store) && "Invalid Opcode"); // Each load/store unit costs 1. unsigned Cost = LT.first * 1; // On Sandybridge 256bit load/stores are double pumped // (but not on Haswell). if (LT.second.getSizeInBits() > 128 && !ST->hasAVX2()) Cost*=2; return Cost; } unsigned X86TTI::getAddressComputationCost(Type *Ty, bool IsComplex) const { // Address computations in vectorized code with non-consecutive addresses will // likely result in more instructions compared to scalar code where the // computation can more often be merged into the index mode. The resulting // extra micro-ops can significantly decrease throughput. unsigned NumVectorInstToHideOverhead = 10; if (Ty->isVectorTy() && IsComplex) return NumVectorInstToHideOverhead; return TargetTransformInfo::getAddressComputationCost(Ty, IsComplex); } unsigned X86TTI::getReductionCost(unsigned Opcode, Type *ValTy, bool IsPairwise) const { std::pair LT = TLI->getTypeLegalizationCost(ValTy); MVT MTy = LT.second; int ISD = TLI->InstructionOpcodeToISD(Opcode); assert(ISD && "Invalid opcode"); // We use the Intel Architecture Code Analyzer(IACA) to measure the throughput // and make it as the cost. static const CostTblEntry SSE42CostTblPairWise[] = { { ISD::FADD, MVT::v2f64, 2 }, { ISD::FADD, MVT::v4f32, 4 }, { ISD::ADD, MVT::v2i64, 2 }, // The data reported by the IACA tool is "1.6". { ISD::ADD, MVT::v4i32, 3 }, // The data reported by the IACA tool is "3.5". { ISD::ADD, MVT::v8i16, 5 }, }; static const CostTblEntry AVX1CostTblPairWise[] = { { ISD::FADD, MVT::v4f32, 4 }, { ISD::FADD, MVT::v4f64, 5 }, { ISD::FADD, MVT::v8f32, 7 }, { ISD::ADD, MVT::v2i64, 1 }, // The data reported by the IACA tool is "1.5". { ISD::ADD, MVT::v4i32, 3 }, // The data reported by the IACA tool is "3.5". { ISD::ADD, MVT::v4i64, 5 }, // The data reported by the IACA tool is "4.8". { ISD::ADD, MVT::v8i16, 5 }, { ISD::ADD, MVT::v8i32, 5 }, }; static const CostTblEntry SSE42CostTblNoPairWise[] = { { ISD::FADD, MVT::v2f64, 2 }, { ISD::FADD, MVT::v4f32, 4 }, { ISD::ADD, MVT::v2i64, 2 }, // The data reported by the IACA tool is "1.6". { ISD::ADD, MVT::v4i32, 3 }, // The data reported by the IACA tool is "3.3". { ISD::ADD, MVT::v8i16, 4 }, // The data reported by the IACA tool is "4.3". }; static const CostTblEntry AVX1CostTblNoPairWise[] = { { ISD::FADD, MVT::v4f32, 3 }, { ISD::FADD, MVT::v4f64, 3 }, { ISD::FADD, MVT::v8f32, 4 }, { ISD::ADD, MVT::v2i64, 1 }, // The data reported by the IACA tool is "1.5". { ISD::ADD, MVT::v4i32, 3 }, // The data reported by the IACA tool is "2.8". { ISD::ADD, MVT::v4i64, 3 }, { ISD::ADD, MVT::v8i16, 4 }, { ISD::ADD, MVT::v8i32, 5 }, }; if (IsPairwise) { if (ST->hasAVX()) { int Idx = CostTableLookup(AVX1CostTblPairWise, ISD, MTy); if (Idx != -1) return LT.first * AVX1CostTblPairWise[Idx].Cost; } if (ST->hasSSE42()) { int Idx = CostTableLookup(SSE42CostTblPairWise, ISD, MTy); if (Idx != -1) return LT.first * SSE42CostTblPairWise[Idx].Cost; } } else { if (ST->hasAVX()) { int Idx = CostTableLookup(AVX1CostTblNoPairWise, ISD, MTy); if (Idx != -1) return LT.first * AVX1CostTblNoPairWise[Idx].Cost; } if (ST->hasSSE42()) { int Idx = CostTableLookup(SSE42CostTblNoPairWise, ISD, MTy); if (Idx != -1) return LT.first * SSE42CostTblNoPairWise[Idx].Cost; } } return TargetTransformInfo::getReductionCost(Opcode, ValTy, IsPairwise); }