llvm-6502/include/llvm/Analysis/TargetTransformInfoImpl.h
Chad Rosier 6229219f7e Prevent hoisting fmul from THEN/ELSE to IF if there is fmsub/fmadd opportunity.
This patch adds the isProfitableToHoist API.  For AArch64, we want to prevent a
fmul from being hoisted in cases where it is more profitable to form a
fmsub/fmadd.

Phabricator Review: http://reviews.llvm.org/D7299
Patch by Lawrence Hu <lawrence@codeaurora.org>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230241 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-23 19:15:16 +00:00

434 lines
15 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/Operator.h"
#include "llvm/IR/Type.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(std::move(Arg.DL)) {}
TargetTransformInfoImplBase &
operator=(const TargetTransformInfoImplBase &RHS) {
DL = RHS.DL;
return *this;
}
TargetTransformInfoImplBase &operator=(TargetTransformInfoImplBase &&RHS) {
DL = std::move(RHS.DL);
return *this;
}
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::IntToPtr: {
if (!DL)
return TTI::TCC_Basic;
// 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: {
if (!DL)
return TTI::TCC_Basic;
// 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 && DL->isLegalInteger(DL->getTypeSizeInBits(Ty)))
return TTI::TCC_Free;
return TTI::TCC_Basic;
}
}
unsigned getGEPCost(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_int:
case Intrinsic::experimental_gc_result_float:
case Intrinsic::experimental_gc_result_ptr:
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 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) {
// Guess that reg+reg addressing is allowed. This heuristic is taken from
// the implementation of LSR.
return !BaseGV && BaseOffset == 0 && Scale <= 1;
}
bool isLegalMaskedStore(Type *DataType, int Consecutive) { return false; }
bool isLegalMaskedLoad(Type *DataType, int Consecutive) { return false; }
int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale) {
// Guess that all legal addressing mode are free.
if (isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg, Scale))
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; }
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 getMaxInterleaveFactor() { 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 getIntrinsicInstrCost(Intrinsic::ID ID, 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;
}
};
/// \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))) {}
TargetTransformInfoImplCRTPBase &
operator=(const TargetTransformInfoImplCRTPBase &RHS) {
BaseT::operator=(static_cast<const BaseT &>(RHS));
return *this;
}
TargetTransformInfoImplCRTPBase &
operator=(TargetTransformInfoImplCRTPBase &&RHS) {
BaseT::operator=(std::move(static_cast<BaseT &>(RHS)));
return *this;
}
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 = (Intrinsic::ID)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::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<const Value *, 4> Indices(GEP->idx_begin(), GEP->idx_end());
return static_cast<T *>(this)
->getGEPCost(GEP->getPointerOperand(), Indices);
}
if (ImmutableCallSite CS = 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