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llvm-mirror/include/llvm/Analysis/TargetTransformInfoImpl.h
Adam Nemet b70814180d [TTI] Add getPrefetchDistance from PPCLoopDataPrefetch, NFC
This patch is part of the work to make PPCLoopDataPrefetch
target-independent
(http://thread.gmane.org/gmane.comp.compilers.llvm.devel/92758).

As it was discussed in the above thread, getPrefetchDistance is
currently using instruction count which may change in the future.

llvm-svn: 258995
2016-01-27 22:21:25 +00:00

517 lines
18 KiB
C++

//===- TargetTransformInfoImpl.h --------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
/// This file provides helpers for the implementation of
/// a TargetTransformInfo-conforming class.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_TARGETTRANSFORMINFOIMPL_H
#define LLVM_ANALYSIS_TARGETTRANSFORMINFOIMPL_H
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/Type.h"
#include "llvm/Analysis/VectorUtils.h"
namespace llvm {
/// \brief Base class for use as a mix-in that aids implementing
/// a TargetTransformInfo-compatible class.
class TargetTransformInfoImplBase {
protected:
typedef TargetTransformInfo TTI;
const DataLayout &DL;
explicit TargetTransformInfoImplBase(const DataLayout &DL) : DL(DL) {}
public:
// Provide value semantics. MSVC requires that we spell all of these out.
TargetTransformInfoImplBase(const TargetTransformInfoImplBase &Arg)
: DL(Arg.DL) {}
TargetTransformInfoImplBase(TargetTransformInfoImplBase &&Arg) : DL(Arg.DL) {}
const DataLayout &getDataLayout() const { return DL; }
unsigned getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) {
switch (Opcode) {
default:
// By default, just classify everything as 'basic'.
return TTI::TCC_Basic;
case Instruction::GetElementPtr:
llvm_unreachable("Use getGEPCost for GEP operations!");
case Instruction::BitCast:
assert(OpTy && "Cast instructions must provide the operand type");
if (Ty == OpTy || (Ty->isPointerTy() && OpTy->isPointerTy()))
// Identity and pointer-to-pointer casts are free.
return TTI::TCC_Free;
// Otherwise, the default basic cost is used.
return TTI::TCC_Basic;
case Instruction::FDiv:
case Instruction::FRem:
case Instruction::SDiv:
case Instruction::SRem:
case Instruction::UDiv:
case Instruction::URem:
return TTI::TCC_Expensive;
case Instruction::IntToPtr: {
// An inttoptr cast is free so long as the input is a legal integer type
// which doesn't contain values outside the range of a pointer.
unsigned OpSize = OpTy->getScalarSizeInBits();
if (DL.isLegalInteger(OpSize) &&
OpSize <= DL.getPointerTypeSizeInBits(Ty))
return TTI::TCC_Free;
// Otherwise it's not a no-op.
return TTI::TCC_Basic;
}
case Instruction::PtrToInt: {
// A ptrtoint cast is free so long as the result is large enough to store
// the pointer, and a legal integer type.
unsigned DestSize = Ty->getScalarSizeInBits();
if (DL.isLegalInteger(DestSize) &&
DestSize >= DL.getPointerTypeSizeInBits(OpTy))
return TTI::TCC_Free;
// Otherwise it's not a no-op.
return TTI::TCC_Basic;
}
case Instruction::Trunc:
// trunc to a native type is free (assuming the target has compare and
// shift-right of the same width).
if (DL.isLegalInteger(DL.getTypeSizeInBits(Ty)))
return TTI::TCC_Free;
return TTI::TCC_Basic;
}
}
unsigned getGEPCost(Type *PointeeType, const Value *Ptr,
ArrayRef<const Value *> Operands) {
// In the basic model, we just assume that all-constant GEPs will be folded
// into their uses via addressing modes.
for (unsigned Idx = 0, Size = Operands.size(); Idx != Size; ++Idx)
if (!isa<Constant>(Operands[Idx]))
return TTI::TCC_Basic;
return TTI::TCC_Free;
}
unsigned getCallCost(FunctionType *FTy, int NumArgs) {
assert(FTy && "FunctionType must be provided to this routine.");
// The target-independent implementation just measures the size of the
// function by approximating that each argument will take on average one
// instruction to prepare.
if (NumArgs < 0)
// Set the argument number to the number of explicit arguments in the
// function.
NumArgs = FTy->getNumParams();
return TTI::TCC_Basic * (NumArgs + 1);
}
unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<Type *> ParamTys) {
switch (IID) {
default:
// Intrinsics rarely (if ever) have normal argument setup constraints.
// Model them as having a basic instruction cost.
// FIXME: This is wrong for libc intrinsics.
return TTI::TCC_Basic;
case Intrinsic::annotation:
case Intrinsic::assume:
case Intrinsic::dbg_declare:
case Intrinsic::dbg_value:
case Intrinsic::invariant_start:
case Intrinsic::invariant_end:
case Intrinsic::lifetime_start:
case Intrinsic::lifetime_end:
case Intrinsic::objectsize:
case Intrinsic::ptr_annotation:
case Intrinsic::var_annotation:
case Intrinsic::experimental_gc_result:
case Intrinsic::experimental_gc_relocate:
// These intrinsics don't actually represent code after lowering.
return TTI::TCC_Free;
}
}
bool hasBranchDivergence() { return false; }
bool isSourceOfDivergence(const Value *V) { return false; }
bool isLoweredToCall(const Function *F) {
// FIXME: These should almost certainly not be handled here, and instead
// handled with the help of TLI or the target itself. This was largely
// ported from existing analysis heuristics here so that such refactorings
// can take place in the future.
if (F->isIntrinsic())
return false;
if (F->hasLocalLinkage() || !F->hasName())
return true;
StringRef Name = F->getName();
// These will all likely lower to a single selection DAG node.
if (Name == "copysign" || Name == "copysignf" || Name == "copysignl" ||
Name == "fabs" || Name == "fabsf" || Name == "fabsl" || Name == "sin" ||
Name == "fmin" || Name == "fminf" || Name == "fminl" ||
Name == "fmax" || Name == "fmaxf" || Name == "fmaxl" ||
Name == "sinf" || Name == "sinl" || Name == "cos" || Name == "cosf" ||
Name == "cosl" || Name == "sqrt" || Name == "sqrtf" || Name == "sqrtl")
return false;
// These are all likely to be optimized into something smaller.
if (Name == "pow" || Name == "powf" || Name == "powl" || Name == "exp2" ||
Name == "exp2l" || Name == "exp2f" || Name == "floor" ||
Name == "floorf" || Name == "ceil" || Name == "round" ||
Name == "ffs" || Name == "ffsl" || Name == "abs" || Name == "labs" ||
Name == "llabs")
return false;
return true;
}
void getUnrollingPreferences(Loop *, TTI::UnrollingPreferences &) {}
bool isLegalAddImmediate(int64_t Imm) { return false; }
bool isLegalICmpImmediate(int64_t Imm) { return false; }
bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale,
unsigned AddrSpace) {
// Guess that only reg and reg+reg addressing is allowed. This heuristic is
// taken from the implementation of LSR.
return !BaseGV && BaseOffset == 0 && (Scale == 0 || Scale == 1);
}
bool isLegalMaskedStore(Type *DataType) { return false; }
bool isLegalMaskedLoad(Type *DataType) { return false; }
bool isLegalMaskedScatter(Type *DataType) { return false; }
bool isLegalMaskedGather(Type *DataType) { return false; }
int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale, unsigned AddrSpace) {
// Guess that all legal addressing mode are free.
if (isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg,
Scale, AddrSpace))
return 0;
return -1;
}
bool isTruncateFree(Type *Ty1, Type *Ty2) { return false; }
bool isProfitableToHoist(Instruction *I) { return true; }
bool isTypeLegal(Type *Ty) { return false; }
unsigned getJumpBufAlignment() { return 0; }
unsigned getJumpBufSize() { return 0; }
bool shouldBuildLookupTables() { return true; }
bool enableAggressiveInterleaving(bool LoopHasReductions) { return false; }
bool enableInterleavedAccessVectorization() { return false; }
TTI::PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) {
return TTI::PSK_Software;
}
bool haveFastSqrt(Type *Ty) { return false; }
unsigned getFPOpCost(Type *Ty) { return TargetTransformInfo::TCC_Basic; }
unsigned getIntImmCost(const APInt &Imm, Type *Ty) { return TTI::TCC_Basic; }
unsigned getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
Type *Ty) {
return TTI::TCC_Free;
}
unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
Type *Ty) {
return TTI::TCC_Free;
}
unsigned getNumberOfRegisters(bool Vector) { return 8; }
unsigned getRegisterBitWidth(bool Vector) { return 32; }
unsigned getCacheLineSize() { return 0; }
unsigned getPrefetchDistance() { return 0; }
unsigned getMaxInterleaveFactor(unsigned VF) { return 1; }
unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty,
TTI::OperandValueKind Opd1Info,
TTI::OperandValueKind Opd2Info,
TTI::OperandValueProperties Opd1PropInfo,
TTI::OperandValueProperties Opd2PropInfo) {
return 1;
}
unsigned getShuffleCost(TTI::ShuffleKind Kind, Type *Ty, int Index,
Type *SubTp) {
return 1;
}
unsigned getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) { return 1; }
unsigned getCFInstrCost(unsigned Opcode) { return 1; }
unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy) {
return 1;
}
unsigned getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
return 1;
}
unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace) {
return 1;
}
unsigned getMaskedMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace) {
return 1;
}
unsigned getGatherScatterOpCost(unsigned Opcode, Type *DataTy, Value *Ptr,
bool VariableMask,
unsigned Alignment) {
return 1;
}
unsigned getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
unsigned Factor,
ArrayRef<unsigned> Indices,
unsigned Alignment,
unsigned AddressSpace) {
return 1;
}
unsigned getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
ArrayRef<Type *> Tys) {
return 1;
}
unsigned getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
ArrayRef<Value *> Args) {
return 1;
}
unsigned getCallInstrCost(Function *F, Type *RetTy, ArrayRef<Type *> Tys) {
return 1;
}
unsigned getNumberOfParts(Type *Tp) { return 0; }
unsigned getAddressComputationCost(Type *Tp, bool) { return 0; }
unsigned getReductionCost(unsigned, Type *, bool) { return 1; }
unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) { return 0; }
bool getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info) {
return false;
}
Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
Type *ExpectedType) {
return nullptr;
}
bool areInlineCompatible(const Function *Caller,
const Function *Callee) const {
return (Caller->getFnAttribute("target-cpu") ==
Callee->getFnAttribute("target-cpu")) &&
(Caller->getFnAttribute("target-features") ==
Callee->getFnAttribute("target-features"));
}
};
/// \brief CRTP base class for use as a mix-in that aids implementing
/// a TargetTransformInfo-compatible class.
template <typename T>
class TargetTransformInfoImplCRTPBase : public TargetTransformInfoImplBase {
private:
typedef TargetTransformInfoImplBase BaseT;
protected:
explicit TargetTransformInfoImplCRTPBase(const DataLayout &DL) : BaseT(DL) {}
public:
// Provide value semantics. MSVC requires that we spell all of these out.
TargetTransformInfoImplCRTPBase(const TargetTransformInfoImplCRTPBase &Arg)
: BaseT(static_cast<const BaseT &>(Arg)) {}
TargetTransformInfoImplCRTPBase(TargetTransformInfoImplCRTPBase &&Arg)
: BaseT(std::move(static_cast<BaseT &>(Arg))) {}
using BaseT::getCallCost;
unsigned getCallCost(const Function *F, int NumArgs) {
assert(F && "A concrete function must be provided to this routine.");
if (NumArgs < 0)
// Set the argument number to the number of explicit arguments in the
// function.
NumArgs = F->arg_size();
if (Intrinsic::ID IID = F->getIntrinsicID()) {
FunctionType *FTy = F->getFunctionType();
SmallVector<Type *, 8> ParamTys(FTy->param_begin(), FTy->param_end());
return static_cast<T *>(this)
->getIntrinsicCost(IID, FTy->getReturnType(), ParamTys);
}
if (!static_cast<T *>(this)->isLoweredToCall(F))
return TTI::TCC_Basic; // Give a basic cost if it will be lowered
// directly.
return static_cast<T *>(this)->getCallCost(F->getFunctionType(), NumArgs);
}
unsigned getCallCost(const Function *F, ArrayRef<const Value *> Arguments) {
// Simply delegate to generic handling of the call.
// FIXME: We should use instsimplify or something else to catch calls which
// will constant fold with these arguments.
return static_cast<T *>(this)->getCallCost(F, Arguments.size());
}
using BaseT::getGEPCost;
unsigned getGEPCost(Type *PointeeType, const Value *Ptr,
ArrayRef<const Value *> Operands) {
const GlobalValue *BaseGV = nullptr;
if (Ptr != nullptr) {
// TODO: will remove this when pointers have an opaque type.
assert(Ptr->getType()->getScalarType()->getPointerElementType() ==
PointeeType &&
"explicit pointee type doesn't match operand's pointee type");
BaseGV = dyn_cast<GlobalValue>(Ptr->stripPointerCasts());
}
bool HasBaseReg = (BaseGV == nullptr);
int64_t BaseOffset = 0;
int64_t Scale = 0;
// Assumes the address space is 0 when Ptr is nullptr.
unsigned AS =
(Ptr == nullptr ? 0 : Ptr->getType()->getPointerAddressSpace());
auto GTI = gep_type_begin(PointeeType, AS, Operands);
for (auto I = Operands.begin(); I != Operands.end(); ++I, ++GTI) {
// We assume that the cost of Scalar GEP with constant index and the
// cost of Vector GEP with splat constant index are the same.
const ConstantInt *ConstIdx = dyn_cast<ConstantInt>(*I);
if (!ConstIdx)
if (auto Splat = getSplatValue(*I))
ConstIdx = dyn_cast<ConstantInt>(Splat);
if (isa<SequentialType>(*GTI)) {
int64_t ElementSize = DL.getTypeAllocSize(GTI.getIndexedType());
if (ConstIdx)
BaseOffset += ConstIdx->getSExtValue() * ElementSize;
else {
// Needs scale register.
if (Scale != 0)
// No addressing mode takes two scale registers.
return TTI::TCC_Basic;
Scale = ElementSize;
}
} else {
StructType *STy = cast<StructType>(*GTI);
// For structures the index is always splat or scalar constant
assert(ConstIdx && "Unexpected GEP index");
uint64_t Field = ConstIdx->getZExtValue();
BaseOffset += DL.getStructLayout(STy)->getElementOffset(Field);
}
}
if (static_cast<T *>(this)->isLegalAddressingMode(
PointerType::get(*GTI, AS), const_cast<GlobalValue *>(BaseGV),
BaseOffset, HasBaseReg, Scale, AS)) {
return TTI::TCC_Free;
}
return TTI::TCC_Basic;
}
using BaseT::getIntrinsicCost;
unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<const Value *> Arguments) {
// Delegate to the generic intrinsic handling code. This mostly provides an
// opportunity for targets to (for example) special case the cost of
// certain intrinsics based on constants used as arguments.
SmallVector<Type *, 8> ParamTys;
ParamTys.reserve(Arguments.size());
for (unsigned Idx = 0, Size = Arguments.size(); Idx != Size; ++Idx)
ParamTys.push_back(Arguments[Idx]->getType());
return static_cast<T *>(this)->getIntrinsicCost(IID, RetTy, ParamTys);
}
unsigned getUserCost(const User *U) {
if (isa<PHINode>(U))
return TTI::TCC_Free; // Model all PHI nodes as free.
if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
SmallVector<Value *, 4> Indices(GEP->idx_begin(), GEP->idx_end());
return static_cast<T *>(this)->getGEPCost(
GEP->getSourceElementType(), GEP->getPointerOperand(), Indices);
}
if (auto CS = ImmutableCallSite(U)) {
const Function *F = CS.getCalledFunction();
if (!F) {
// Just use the called value type.
Type *FTy = CS.getCalledValue()->getType()->getPointerElementType();
return static_cast<T *>(this)
->getCallCost(cast<FunctionType>(FTy), CS.arg_size());
}
SmallVector<const Value *, 8> Arguments(CS.arg_begin(), CS.arg_end());
return static_cast<T *>(this)->getCallCost(F, Arguments);
}
if (const CastInst *CI = dyn_cast<CastInst>(U)) {
// Result of a cmp instruction is often extended (to be used by other
// cmp instructions, logical or return instructions). These are usually
// nop on most sane targets.
if (isa<CmpInst>(CI->getOperand(0)))
return TTI::TCC_Free;
}
return static_cast<T *>(this)->getOperationCost(
Operator::getOpcode(U), U->getType(),
U->getNumOperands() == 1 ? U->getOperand(0)->getType() : nullptr);
}
};
}
#endif