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-rw-r--r--lib/Target/X86/X86TargetTransformInfo.cpp355
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diff --git a/lib/Target/X86/X86TargetTransformInfo.cpp b/lib/Target/X86/X86TargetTransformInfo.cpp
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+//===-- 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/Support/Debug.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/TargetTransformInfo.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 X86TargetMachine *TM;
+ 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), TM(0), ST(0), TLI(0) {
+ llvm_unreachable("This pass cannot be directly constructed");
+ }
+
+ X86TTI(const X86TargetMachine *TM)
+ : ImmutablePass(ID), TM(TM), 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 PopcntHwSupport getPopcntHwSupport(unsigned TyWidth) const;
+
+ /// @}
+
+ /// \name Vector TTI Implementations
+ /// @{
+
+ virtual unsigned getNumberOfRegisters(bool Vector) const;
+ virtual unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty) 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;
+
+ /// @}
+};
+
+} // 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.
+//
+//===----------------------------------------------------------------------===//
+
+namespace {
+struct X86CostTblEntry {
+ int ISD;
+ MVT Type;
+ unsigned Cost;
+};
+}
+
+static int
+FindInTable(const X86CostTblEntry *Tbl, unsigned len, int ISD, MVT Ty) {
+ for (unsigned int i = 0; i < len; ++i)
+ if (Tbl[i].ISD == ISD && Tbl[i].Type == Ty)
+ return i;
+
+ // Could not find an entry.
+ return -1;
+}
+
+namespace {
+struct X86TypeConversionCostTblEntry {
+ int ISD;
+ MVT Dst;
+ MVT Src;
+ unsigned Cost;
+};
+}
+
+static int
+FindInConvertTable(const X86TypeConversionCostTblEntry *Tbl, unsigned len,
+ int ISD, MVT Dst, MVT Src) {
+ for (unsigned int i = 0; i < len; ++i)
+ if (Tbl[i].ISD == ISD && Tbl[i].Src == Src && Tbl[i].Dst == Dst)
+ return i;
+
+ // Could not find an entry.
+ return -1;
+}
+
+
+X86TTI::PopcntHwSupport X86TTI::getPopcntHwSupport(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->hasSSE4().
+ return ST->hasSSE41() ? Fast : None;
+}
+
+unsigned X86TTI::getNumberOfRegisters(bool Vector) const {
+ if (ST->is64Bit())
+ return 16;
+ return 8;
+}
+
+unsigned X86TTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty) const {
+ // Legalize the type.
+ std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Ty);
+
+ int ISD = TLI->InstructionOpcodeToISD(Opcode);
+ assert(ISD && "Invalid opcode");
+
+ static const X86CostTblEntry 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::MUL, MVT::v4i64, 4 },
+ { ISD::SUB, MVT::v4i64, 4 },
+ { ISD::ADD, MVT::v4i64, 4 },
+ };
+
+ // Look for AVX1 lowering tricks.
+ if (ST->hasAVX()) {
+ int Idx = FindInTable(AVX1CostTable, array_lengthof(AVX1CostTable), ISD,
+ LT.second);
+ if (Idx != -1)
+ return LT.first * AVX1CostTable[Idx].Cost;
+ }
+ // Fallback to the default implementation.
+ return TargetTransformInfo::getArithmeticInstrCost(Opcode, Ty);
+}
+
+unsigned X86TTI::getShuffleCost(ShuffleKind Kind, Type *Tp, int Index,
+ Type *SubTp) const {
+ // We only estimate the cost of reverse shuffles.
+ if (Kind != Reverse)
+ return TargetTransformInfo::getShuffleCost(Kind, Tp, Index, SubTp);
+
+ std::pair<unsigned, MVT> 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");
+
+ EVT SrcTy = TLI->getValueType(Src);
+ EVT DstTy = TLI->getValueType(Dst);
+
+ if (!SrcTy.isSimple() || !DstTy.isSimple())
+ return TargetTransformInfo::getCastInstrCost(Opcode, Dst, Src);
+
+ static const X86TypeConversionCostTblEntry AVXConversionTbl[] = {
+ { 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::SINT_TO_FP, MVT::v8f32, MVT::v8i8, 1 },
+ { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i8, 1 },
+ { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i8, 1 },
+ { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i8, 1 },
+ { 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::TRUNCATE, MVT::v8i32, MVT::v8i64, 3 },
+ };
+
+ if (ST->hasAVX()) {
+ int Idx = FindInConvertTable(AVXConversionTbl,
+ array_lengthof(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<unsigned, MVT> LT = TLI->getTypeLegalizationCost(ValTy);
+
+ MVT MTy = LT.second;
+
+ int ISD = TLI->InstructionOpcodeToISD(Opcode);
+ assert(ISD && "Invalid opcode");
+
+ static const X86CostTblEntry 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 X86CostTblEntry 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 X86CostTblEntry 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 = FindInTable(AVX2CostTbl, array_lengthof(AVX2CostTbl), ISD, MTy);
+ if (Idx != -1)
+ return LT.first * AVX2CostTbl[Idx].Cost;
+ }
+
+ if (ST->hasAVX()) {
+ int Idx = FindInTable(AVX1CostTbl, array_lengthof(AVX1CostTbl), ISD, MTy);
+ if (Idx != -1)
+ return LT.first * AVX1CostTbl[Idx].Cost;
+ }
+
+ if (ST->hasSSE42()) {
+ int Idx = FindInTable(SSE42CostTbl, array_lengthof(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<unsigned, MVT> 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::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
+ unsigned AddressSpace) const {
+ // Legalize the type.
+ std::pair<unsigned, MVT> 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;
+}
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