Mercurial > hg > Members > tobaru > cbc > CbC_llvm
diff lib/Target/PowerPC/PPCTargetTransformInfo.cpp @ 0:95c75e76d11b
LLVM 3.4
author | Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> |
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date | Thu, 12 Dec 2013 13:56:28 +0900 |
parents | |
children | 54457678186b |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib/Target/PowerPC/PPCTargetTransformInfo.cpp Thu Dec 12 13:56:28 2013 +0900 @@ -0,0 +1,249 @@ +//===-- PPCTargetTransformInfo.cpp - PPC 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 +/// PPC 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 "ppctti" +#include "PPC.h" +#include "PPCTargetMachine.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 initializePPCTTIPass(PassRegistry &); +} + +namespace { + +class PPCTTI : public ImmutablePass, public TargetTransformInfo { + const PPCTargetMachine *TM; + const PPCSubtarget *ST; + const PPCTargetLowering *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: + PPCTTI() : ImmutablePass(ID), TM(0), ST(0), TLI(0) { + llvm_unreachable("This pass cannot be directly constructed"); + } + + PPCTTI(const PPCTargetMachine *TM) + : ImmutablePass(ID), TM(TM), ST(TM->getSubtargetImpl()), + TLI(TM->getTargetLowering()) { + initializePPCTTIPass(*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; + virtual void getUnrollingPreferences(Loop *L, UnrollingPreferences &UP) 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; + + /// @} +}; + +} // end anonymous namespace + +INITIALIZE_AG_PASS(PPCTTI, TargetTransformInfo, "ppctti", + "PPC Target Transform Info", true, true, false) +char PPCTTI::ID = 0; + +ImmutablePass * +llvm::createPPCTargetTransformInfoPass(const PPCTargetMachine *TM) { + return new PPCTTI(TM); +} + + +//===----------------------------------------------------------------------===// +// +// PPC cost model. +// +//===----------------------------------------------------------------------===// + +PPCTTI::PopcntSupportKind PPCTTI::getPopcntSupport(unsigned TyWidth) const { + assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2"); + if (ST->hasPOPCNTD() && TyWidth <= 64) + return PSK_FastHardware; + return PSK_Software; +} + +void PPCTTI::getUnrollingPreferences(Loop *L, UnrollingPreferences &UP) const { + if (ST->getDarwinDirective() == PPC::DIR_A2) { + // The A2 is in-order with a deep pipeline, and concatenation unrolling + // helps expose latency-hiding opportunities to the instruction scheduler. + UP.Partial = UP.Runtime = true; + } +} + +unsigned PPCTTI::getNumberOfRegisters(bool Vector) const { + if (Vector && !ST->hasAltivec()) + return 0; + return 32; +} + +unsigned PPCTTI::getRegisterBitWidth(bool Vector) const { + if (Vector) { + if (ST->hasAltivec()) return 128; + return 0; + } + + if (ST->isPPC64()) + return 64; + return 32; + +} + +unsigned PPCTTI::getMaximumUnrollFactor() const { + unsigned Directive = ST->getDarwinDirective(); + // The 440 has no SIMD support, but floating-point instructions + // have a 5-cycle latency, so unroll by 5x for latency hiding. + if (Directive == PPC::DIR_440) + return 5; + + // The A2 has no SIMD support, but floating-point instructions + // have a 6-cycle latency, so unroll by 6x for latency hiding. + if (Directive == PPC::DIR_A2) + return 6; + + // FIXME: For lack of any better information, do no harm... + if (Directive == PPC::DIR_E500mc || Directive == PPC::DIR_E5500) + return 1; + + // For most things, modern systems have two execution units (and + // out-of-order execution). + return 2; +} + +unsigned PPCTTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty, + OperandValueKind Op1Info, + OperandValueKind Op2Info) const { + assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode"); + + // Fallback to the default implementation. + return TargetTransformInfo::getArithmeticInstrCost(Opcode, Ty, Op1Info, + Op2Info); +} + +unsigned PPCTTI::getShuffleCost(ShuffleKind Kind, Type *Tp, int Index, + Type *SubTp) const { + return TargetTransformInfo::getShuffleCost(Kind, Tp, Index, SubTp); +} + +unsigned PPCTTI::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) const { + assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode"); + + return TargetTransformInfo::getCastInstrCost(Opcode, Dst, Src); +} + +unsigned PPCTTI::getCmpSelInstrCost(unsigned Opcode, Type *ValTy, + Type *CondTy) const { + return TargetTransformInfo::getCmpSelInstrCost(Opcode, ValTy, CondTy); +} + +unsigned PPCTTI::getVectorInstrCost(unsigned Opcode, Type *Val, + unsigned Index) const { + assert(Val->isVectorTy() && "This must be a vector type"); + + int ISD = TLI->InstructionOpcodeToISD(Opcode); + assert(ISD && "Invalid opcode"); + + // Estimated cost of a load-hit-store delay. This was obtained + // experimentally as a minimum needed to prevent unprofitable + // vectorization for the paq8p benchmark. It may need to be + // raised further if other unprofitable cases remain. + unsigned LHSPenalty = 12; + + // Vector element insert/extract with Altivec is very expensive, + // because they require store and reload with the attendant + // processor stall for load-hit-store. Until VSX is available, + // these need to be estimated as very costly. + if (ISD == ISD::EXTRACT_VECTOR_ELT || + ISD == ISD::INSERT_VECTOR_ELT) + return LHSPenalty + + TargetTransformInfo::getVectorInstrCost(Opcode, Val, Index); + + return TargetTransformInfo::getVectorInstrCost(Opcode, Val, Index); +} + +unsigned PPCTTI::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; + + // PPC in general does not support unaligned loads and stores. They'll need + // to be decomposed based on the alignment factor. + unsigned SrcBytes = LT.second.getStoreSize(); + if (SrcBytes && Alignment && Alignment < SrcBytes) + Cost *= (SrcBytes/Alignment); + + return Cost; +} +