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llvm-mirror/include/llvm/CodeGen/BasicTTIImpl.h
Michael Kuperstein 57fc4a3484 [X86] Add costs for SSE zext/sext to v4i64 to TTI 
The costs are somewhat hand-wavy, but should be much closer to the truth
than what we get from BasicTTI.

Differential Revision: http://reviews.llvm.org/D21156

llvm-svn: 272406
2016-06-10 17:01:05 +00:00

938 lines
34 KiB
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//===- BasicTTIImpl.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 a helper that implements much of the TTI interface in
/// terms of the target-independent code generator and TargetLowering
/// interfaces.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_BASICTTIIMPL_H
#define LLVM_CODEGEN_BASICTTIIMPL_H
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/TargetTransformInfoImpl.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
namespace llvm {
extern cl::opt<unsigned> PartialUnrollingThreshold;
/// \brief Base class which can be used to help build a TTI implementation.
///
/// This class provides as much implementation of the TTI interface as is
/// possible using the target independent parts of the code generator.
///
/// In order to subclass it, your class must implement a getST() method to
/// return the subtarget, and a getTLI() method to return the target lowering.
/// We need these methods implemented in the derived class so that this class
/// doesn't have to duplicate storage for them.
template <typename T>
class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
private:
typedef TargetTransformInfoImplCRTPBase<T> BaseT;
typedef TargetTransformInfo TTI;
/// 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) {
assert(Ty->isVectorTy() && "Can only scalarize vectors");
unsigned Cost = 0;
for (int i = 0, e = Ty->getVectorNumElements(); i < e; ++i) {
if (Insert)
Cost += static_cast<T *>(this)
->getVectorInstrCost(Instruction::InsertElement, Ty, i);
if (Extract)
Cost += static_cast<T *>(this)
->getVectorInstrCost(Instruction::ExtractElement, Ty, i);
}
return Cost;
}
/// Estimate the cost overhead of SK_Alternate shuffle.
unsigned getAltShuffleOverhead(Type *Ty) {
assert(Ty->isVectorTy() && "Can only shuffle vectors");
unsigned Cost = 0;
// Shuffle cost is equal to the cost of extracting element from its argument
// plus the cost of inserting them onto the result vector.
// e.g. <4 x float> has a mask of <0,5,2,7> i.e we need to extract from
// index 0 of first vector, index 1 of second vector,index 2 of first
// vector and finally index 3 of second vector and insert them at index
// <0,1,2,3> of result vector.
for (int i = 0, e = Ty->getVectorNumElements(); i < e; ++i) {
Cost += static_cast<T *>(this)
->getVectorInstrCost(Instruction::InsertElement, Ty, i);
Cost += static_cast<T *>(this)
->getVectorInstrCost(Instruction::ExtractElement, Ty, i);
}
return Cost;
}
/// \brief Local query method delegates up to T which *must* implement this!
const TargetSubtargetInfo *getST() const {
return static_cast<const T *>(this)->getST();
}
/// \brief Local query method delegates up to T which *must* implement this!
const TargetLoweringBase *getTLI() const {
return static_cast<const T *>(this)->getTLI();
}
protected:
explicit BasicTTIImplBase(const TargetMachine *TM, const DataLayout &DL)
: BaseT(DL) {}
using TargetTransformInfoImplBase::DL;
public:
// Provide value semantics. MSVC requires that we spell all of these out.
BasicTTIImplBase(const BasicTTIImplBase &Arg)
: BaseT(static_cast<const BaseT &>(Arg)) {}
BasicTTIImplBase(BasicTTIImplBase &&Arg)
: BaseT(std::move(static_cast<BaseT &>(Arg))) {}
/// \name Scalar TTI Implementations
/// @{
bool hasBranchDivergence() { return false; }
bool isSourceOfDivergence(const Value *V) { return false; }
bool isLegalAddImmediate(int64_t imm) {
return getTLI()->isLegalAddImmediate(imm);
}
bool isLegalICmpImmediate(int64_t imm) {
return getTLI()->isLegalICmpImmediate(imm);
}
bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale,
unsigned AddrSpace) {
TargetLoweringBase::AddrMode AM;
AM.BaseGV = BaseGV;
AM.BaseOffs = BaseOffset;
AM.HasBaseReg = HasBaseReg;
AM.Scale = Scale;
return getTLI()->isLegalAddressingMode(DL, AM, Ty, AddrSpace);
}
int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale, unsigned AddrSpace) {
TargetLoweringBase::AddrMode AM;
AM.BaseGV = BaseGV;
AM.BaseOffs = BaseOffset;
AM.HasBaseReg = HasBaseReg;
AM.Scale = Scale;
return getTLI()->getScalingFactorCost(DL, AM, Ty, AddrSpace);
}
bool isTruncateFree(Type *Ty1, Type *Ty2) {
return getTLI()->isTruncateFree(Ty1, Ty2);
}
bool isProfitableToHoist(Instruction *I) {
return getTLI()->isProfitableToHoist(I);
}
bool isTypeLegal(Type *Ty) {
EVT VT = getTLI()->getValueType(DL, Ty);
return getTLI()->isTypeLegal(VT);
}
unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<const Value *> Arguments) {
return BaseT::getIntrinsicCost(IID, RetTy, Arguments);
}
unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<Type *> ParamTys) {
if (IID == Intrinsic::cttz) {
if (getTLI()->isCheapToSpeculateCttz())
return TargetTransformInfo::TCC_Basic;
return TargetTransformInfo::TCC_Expensive;
}
if (IID == Intrinsic::ctlz) {
if (getTLI()->isCheapToSpeculateCtlz())
return TargetTransformInfo::TCC_Basic;
return TargetTransformInfo::TCC_Expensive;
}
return BaseT::getIntrinsicCost(IID, RetTy, ParamTys);
}
unsigned getJumpBufAlignment() { return getTLI()->getJumpBufAlignment(); }
unsigned getJumpBufSize() { return getTLI()->getJumpBufSize(); }
bool shouldBuildLookupTables() {
const TargetLoweringBase *TLI = getTLI();
return TLI->isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
TLI->isOperationLegalOrCustom(ISD::BRIND, MVT::Other);
}
bool haveFastSqrt(Type *Ty) {
const TargetLoweringBase *TLI = getTLI();
EVT VT = TLI->getValueType(DL, Ty);
return TLI->isTypeLegal(VT) &&
TLI->isOperationLegalOrCustom(ISD::FSQRT, VT);
}
unsigned getFPOpCost(Type *Ty) {
// By default, FP instructions are no more expensive since they are
// implemented in HW. Target specific TTI can override this.
return TargetTransformInfo::TCC_Basic;
}
unsigned getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) {
const TargetLoweringBase *TLI = getTLI();
switch (Opcode) {
default: break;
case Instruction::Trunc: {
if (TLI->isTruncateFree(OpTy, Ty))
return TargetTransformInfo::TCC_Free;
return TargetTransformInfo::TCC_Basic;
}
case Instruction::ZExt: {
if (TLI->isZExtFree(OpTy, Ty))
return TargetTransformInfo::TCC_Free;
return TargetTransformInfo::TCC_Basic;
}
}
return BaseT::getOperationCost(Opcode, Ty, OpTy);
}
unsigned getInliningThresholdMultiplier() { return 1; }
void getUnrollingPreferences(Loop *L, TTI::UnrollingPreferences &UP) {
// This unrolling functionality is target independent, but to provide some
// motivation for its intended use, for x86:
// According to the Intel 64 and IA-32 Architectures Optimization Reference
// Manual, Intel Core models and later have a loop stream detector (and
// associated uop queue) that can benefit from partial unrolling.
// The relevant requirements are:
// - The loop must have no more than 4 (8 for Nehalem and later) branches
// taken, and none of them may be calls.
// - The loop can have no more than 18 (28 for Nehalem and later) uops.
// According to the Software Optimization Guide for AMD Family 15h
// Processors, models 30h-4fh (Steamroller and later) have a loop predictor
// and loop buffer which can benefit from partial unrolling.
// The relevant requirements are:
// - The loop must have fewer than 16 branches
// - The loop must have less than 40 uops in all executed loop branches
// The number of taken branches in a loop is hard to estimate here, and
// benchmarking has revealed that it is better not to be conservative when
// estimating the branch count. As a result, we'll ignore the branch limits
// until someone finds a case where it matters in practice.
unsigned MaxOps;
const TargetSubtargetInfo *ST = getST();
if (PartialUnrollingThreshold.getNumOccurrences() > 0)
MaxOps = PartialUnrollingThreshold;
else if (ST->getSchedModel().LoopMicroOpBufferSize > 0)
MaxOps = ST->getSchedModel().LoopMicroOpBufferSize;
else
return;
// Scan the loop: don't unroll loops with calls.
for (Loop::block_iterator I = L->block_begin(), E = L->block_end(); I != E;
++I) {
BasicBlock *BB = *I;
for (BasicBlock::iterator J = BB->begin(), JE = BB->end(); J != JE; ++J)
if (isa<CallInst>(J) || isa<InvokeInst>(J)) {
ImmutableCallSite CS(&*J);
if (const Function *F = CS.getCalledFunction()) {
if (!static_cast<T *>(this)->isLoweredToCall(F))
continue;
}
return;
}
}
// Enable runtime and partial unrolling up to the specified size.
UP.Partial = UP.Runtime = true;
UP.PartialThreshold = UP.PartialOptSizeThreshold = MaxOps;
}
/// @}
/// \name Vector TTI Implementations
/// @{
unsigned getNumberOfRegisters(bool Vector) { return Vector ? 0 : 1; }
unsigned getRegisterBitWidth(bool Vector) { return 32; }
unsigned getMaxInterleaveFactor(unsigned VF) { return 1; }
unsigned getArithmeticInstrCost(
unsigned Opcode, Type *Ty,
TTI::OperandValueKind Opd1Info = TTI::OK_AnyValue,
TTI::OperandValueKind Opd2Info = TTI::OK_AnyValue,
TTI::OperandValueProperties Opd1PropInfo = TTI::OP_None,
TTI::OperandValueProperties Opd2PropInfo = TTI::OP_None) {
// Check if any of the operands are vector operands.
const TargetLoweringBase *TLI = getTLI();
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(DL, Ty);
bool IsFloat = Ty->getScalarType()->isFloatingPointTy();
// Assume that floating point arithmetic operations cost twice as much as
// integer operations.
unsigned OpCost = (IsFloat ? 2 : 1);
if (TLI->isOperationLegalOrPromote(ISD, LT.second)) {
// The operation is legal. Assume it costs 1.
// TODO: Once we have extract/insert subvector cost we need to use them.
return LT.first * OpCost;
}
if (!TLI->isOperationExpand(ISD, LT.second)) {
// If the operation is custom lowered, then assume that the code is twice
// as expensive.
return LT.first * 2 * OpCost;
}
// Else, assume that we need to scalarize this op.
if (Ty->isVectorTy()) {
unsigned Num = Ty->getVectorNumElements();
unsigned Cost = static_cast<T *>(this)
->getArithmeticInstrCost(Opcode, Ty->getScalarType());
// return the cost of multiple scalar invocation plus the cost of
// inserting
// and extracting the values.
return getScalarizationOverhead(Ty, true, true) + Num * Cost;
}
// We don't know anything about this scalar instruction.
return OpCost;
}
unsigned getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, int Index,
Type *SubTp) {
if (Kind == TTI::SK_Alternate) {
return getAltShuffleOverhead(Tp);
}
return 1;
}
unsigned getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) {
const TargetLoweringBase *TLI = getTLI();
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
std::pair<unsigned, MVT> SrcLT = TLI->getTypeLegalizationCost(DL, Src);
std::pair<unsigned, MVT> DstLT = TLI->getTypeLegalizationCost(DL, Dst);
// Check for NOOP conversions.
if (SrcLT.first == DstLT.first &&
SrcLT.second.getSizeInBits() == DstLT.second.getSizeInBits()) {
// Bitcast between types that are legalized to the same type are free.
if (Opcode == Instruction::BitCast || Opcode == Instruction::Trunc)
return 0;
}
if (Opcode == Instruction::Trunc &&
TLI->isTruncateFree(SrcLT.second, DstLT.second))
return 0;
if (Opcode == Instruction::ZExt &&
TLI->isZExtFree(SrcLT.second, DstLT.second))
return 0;
if (Opcode == Instruction::AddrSpaceCast &&
TLI->isNoopAddrSpaceCast(Src->getPointerAddressSpace(),
Dst->getPointerAddressSpace()))
return 0;
// If the cast is marked as legal (or promote) then assume low cost.
if (SrcLT.first == DstLT.first &&
TLI->isOperationLegalOrPromote(ISD, DstLT.second))
return 1;
// Handle scalar conversions.
if (!Src->isVectorTy() && !Dst->isVectorTy()) {
// Scalar bitcasts are usually free.
if (Opcode == Instruction::BitCast)
return 0;
// Just check the op cost. If the operation is legal then assume it costs
// 1.
if (!TLI->isOperationExpand(ISD, DstLT.second))
return 1;
// Assume that illegal scalar instruction are expensive.
return 4;
}
// Check vector-to-vector casts.
if (Dst->isVectorTy() && Src->isVectorTy()) {
// If the cast is between same-sized registers, then the check is simple.
if (SrcLT.first == DstLT.first &&
SrcLT.second.getSizeInBits() == DstLT.second.getSizeInBits()) {
// Assume that Zext is done using AND.
if (Opcode == Instruction::ZExt)
return 1;
// Assume that sext is done using SHL and SRA.
if (Opcode == Instruction::SExt)
return 2;
// Just check the op cost. If the operation is legal then assume it
// costs
// 1 and multiply by the type-legalization overhead.
if (!TLI->isOperationExpand(ISD, DstLT.second))
return SrcLT.first * 1;
}
// If we are converting vectors and the operation is illegal, or
// if the vectors are legalized to different types, estimate the
// scalarization costs.
// TODO: This is probably a big overestimate. For splits, we should have
// something like getTypeLegalizationCost() + 2 * getCastInstrCost().
// The same applies to getCmpSelInstrCost() and getArithmeticInstrCost()
unsigned Num = Dst->getVectorNumElements();
unsigned Cost = static_cast<T *>(this)->getCastInstrCost(
Opcode, Dst->getScalarType(), Src->getScalarType());
// Return the cost of multiple scalar invocation plus the cost of
// inserting and extracting the values.
return getScalarizationOverhead(Dst, true, true) + Num * Cost;
}
// We already handled vector-to-vector and scalar-to-scalar conversions.
// This
// is where we handle bitcast between vectors and scalars. We need to assume
// that the conversion is scalarized in one way or another.
if (Opcode == Instruction::BitCast)
// Illegal bitcasts are done by storing and loading from a stack slot.
return (Src->isVectorTy() ? getScalarizationOverhead(Src, false, true)
: 0) +
(Dst->isVectorTy() ? getScalarizationOverhead(Dst, true, false)
: 0);
llvm_unreachable("Unhandled cast");
}
unsigned getExtractWithExtendCost(unsigned Opcode, Type *Dst,
VectorType *VecTy, unsigned Index) {
return static_cast<T *>(this)->getVectorInstrCost(
Instruction::ExtractElement, VecTy, Index) +
static_cast<T *>(this)->getCastInstrCost(Opcode, Dst,
VecTy->getElementType());
}
unsigned getCFInstrCost(unsigned Opcode) {
// Branches are assumed to be predicted.
return 0;
}
unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy) {
const TargetLoweringBase *TLI = getTLI();
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
// Selects on vectors are actually vector selects.
if (ISD == ISD::SELECT) {
assert(CondTy && "CondTy must exist");
if (CondTy->isVectorTy())
ISD = ISD::VSELECT;
}
std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(DL, ValTy);
if (!(ValTy->isVectorTy() && !LT.second.isVector()) &&
!TLI->isOperationExpand(ISD, LT.second)) {
// The operation is legal. Assume it costs 1. Multiply
// by the type-legalization overhead.
return LT.first * 1;
}
// Otherwise, assume that the cast is scalarized.
if (ValTy->isVectorTy()) {
unsigned Num = ValTy->getVectorNumElements();
if (CondTy)
CondTy = CondTy->getScalarType();
unsigned Cost = static_cast<T *>(this)->getCmpSelInstrCost(
Opcode, ValTy->getScalarType(), CondTy);
// Return the cost of multiple scalar invocation plus the cost of
// inserting
// and extracting the values.
return getScalarizationOverhead(ValTy, true, false) + Num * Cost;
}
// Unknown scalar opcode.
return 1;
}
unsigned getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
std::pair<unsigned, MVT> LT =
getTLI()->getTypeLegalizationCost(DL, Val->getScalarType());
return LT.first;
}
unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace) {
assert(!Src->isVoidTy() && "Invalid type");
std::pair<unsigned, MVT> LT = getTLI()->getTypeLegalizationCost(DL, Src);
// Assuming that all loads of legal types cost 1.
unsigned Cost = LT.first;
if (Src->isVectorTy() &&
Src->getPrimitiveSizeInBits() < LT.second.getSizeInBits()) {
// This is a vector load that legalizes to a larger type than the vector
// itself. Unless the corresponding extending load or truncating store is
// legal, then this will scalarize.
TargetLowering::LegalizeAction LA = TargetLowering::Expand;
EVT MemVT = getTLI()->getValueType(DL, Src);
if (Opcode == Instruction::Store)
LA = getTLI()->getTruncStoreAction(LT.second, MemVT);
else
LA = getTLI()->getLoadExtAction(ISD::EXTLOAD, LT.second, MemVT);
if (LA != TargetLowering::Legal && LA != TargetLowering::Custom) {
// This is a vector load/store for some illegal type that is scalarized.
// We must account for the cost of building or decomposing the vector.
Cost += getScalarizationOverhead(Src, Opcode != Instruction::Store,
Opcode == Instruction::Store);
}
}
return Cost;
}
unsigned getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
unsigned Factor,
ArrayRef<unsigned> Indices,
unsigned Alignment,
unsigned AddressSpace) {
VectorType *VT = dyn_cast<VectorType>(VecTy);
assert(VT && "Expect a vector type for interleaved memory op");
unsigned NumElts = VT->getNumElements();
assert(Factor > 1 && NumElts % Factor == 0 && "Invalid interleave factor");
unsigned NumSubElts = NumElts / Factor;
VectorType *SubVT = VectorType::get(VT->getElementType(), NumSubElts);
// Firstly, the cost of load/store operation.
unsigned Cost = static_cast<T *>(this)->getMemoryOpCost(
Opcode, VecTy, Alignment, AddressSpace);
// Legalize the vector type, and get the legalized and unlegalized type
// sizes.
MVT VecTyLT = getTLI()->getTypeLegalizationCost(DL, VecTy).second;
unsigned VecTySize =
static_cast<T *>(this)->getDataLayout().getTypeStoreSize(VecTy);
unsigned VecTyLTSize = VecTyLT.getStoreSize();
// Return the ceiling of dividing A by B.
auto ceil = [](unsigned A, unsigned B) { return (A + B - 1) / B; };
// Scale the cost of the memory operation by the fraction of legalized
// instructions that will actually be used. We shouldn't account for the
// cost of dead instructions since they will be removed.
//
// E.g., An interleaved load of factor 8:
// %vec = load <16 x i64>, <16 x i64>* %ptr
// %v0 = shufflevector %vec, undef, <0, 8>
//
// If <16 x i64> is legalized to 8 v2i64 loads, only 2 of the loads will be
// used (those corresponding to elements [0:1] and [8:9] of the unlegalized
// type). The other loads are unused.
//
// We only scale the cost of loads since interleaved store groups aren't
// allowed to have gaps.
if (Opcode == Instruction::Load && VecTySize > VecTyLTSize) {
// The number of loads of a legal type it will take to represent a load
// of the unlegalized vector type.
unsigned NumLegalInsts = ceil(VecTySize, VecTyLTSize);
// The number of elements of the unlegalized type that correspond to a
// single legal instruction.
unsigned NumEltsPerLegalInst = ceil(NumElts, NumLegalInsts);
// Determine which legal instructions will be used.
BitVector UsedInsts(NumLegalInsts, false);
for (unsigned Index : Indices)
for (unsigned Elt = 0; Elt < NumSubElts; ++Elt)
UsedInsts.set((Index + Elt * Factor) / NumEltsPerLegalInst);
// Scale the cost of the load by the fraction of legal instructions that
// will be used.
Cost *= UsedInsts.count() / NumLegalInsts;
}
// Then plus the cost of interleave operation.
if (Opcode == Instruction::Load) {
// The interleave cost is similar to extract sub vectors' elements
// from the wide vector, and insert them into sub vectors.
//
// E.g. An interleaved load of factor 2 (with one member of index 0):
// %vec = load <8 x i32>, <8 x i32>* %ptr
// %v0 = shuffle %vec, undef, <0, 2, 4, 6> ; Index 0
// The cost is estimated as extract elements at 0, 2, 4, 6 from the
// <8 x i32> vector and insert them into a <4 x i32> vector.
assert(Indices.size() <= Factor &&
"Interleaved memory op has too many members");
for (unsigned Index : Indices) {
assert(Index < Factor && "Invalid index for interleaved memory op");
// Extract elements from loaded vector for each sub vector.
for (unsigned i = 0; i < NumSubElts; i++)
Cost += static_cast<T *>(this)->getVectorInstrCost(
Instruction::ExtractElement, VT, Index + i * Factor);
}
unsigned InsSubCost = 0;
for (unsigned i = 0; i < NumSubElts; i++)
InsSubCost += static_cast<T *>(this)->getVectorInstrCost(
Instruction::InsertElement, SubVT, i);
Cost += Indices.size() * InsSubCost;
} else {
// The interleave cost is extract all elements from sub vectors, and
// insert them into the wide vector.
//
// E.g. An interleaved store of factor 2:
// %v0_v1 = shuffle %v0, %v1, <0, 4, 1, 5, 2, 6, 3, 7>
// store <8 x i32> %interleaved.vec, <8 x i32>* %ptr
// The cost is estimated as extract all elements from both <4 x i32>
// vectors and insert into the <8 x i32> vector.
unsigned ExtSubCost = 0;
for (unsigned i = 0; i < NumSubElts; i++)
ExtSubCost += static_cast<T *>(this)->getVectorInstrCost(
Instruction::ExtractElement, SubVT, i);
Cost += ExtSubCost * Factor;
for (unsigned i = 0; i < NumElts; i++)
Cost += static_cast<T *>(this)
->getVectorInstrCost(Instruction::InsertElement, VT, i);
}
return Cost;
}
/// Get intrinsic cost based on arguments
unsigned getIntrinsicInstrCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<Value *> Args, FastMathFlags FMF) {
switch (IID) {
default: {
SmallVector<Type *, 4> Types;
for (Value *Op : Args)
Types.push_back(Op->getType());
return static_cast<T *>(this)->getIntrinsicInstrCost(IID, RetTy, Types,
FMF);
}
case Intrinsic::masked_scatter: {
Value *Mask = Args[3];
bool VarMask = !isa<Constant>(Mask);
unsigned Alignment = cast<ConstantInt>(Args[2])->getZExtValue();
return
static_cast<T *>(this)->getGatherScatterOpCost(Instruction::Store,
Args[0]->getType(),
Args[1], VarMask,
Alignment);
}
case Intrinsic::masked_gather: {
Value *Mask = Args[2];
bool VarMask = !isa<Constant>(Mask);
unsigned Alignment = cast<ConstantInt>(Args[1])->getZExtValue();
return
static_cast<T *>(this)->getGatherScatterOpCost(Instruction::Load,
RetTy, Args[0], VarMask,
Alignment);
}
}
}
/// Get intrinsic cost based on argument types
unsigned getIntrinsicInstrCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<Type *> Tys, FastMathFlags FMF) {
SmallVector<unsigned, 2> ISDs;
unsigned SingleCallCost = 10; // Library call cost. Make it expensive.
switch (IID) {
default: {
// Assume that we need to scalarize this intrinsic.
unsigned ScalarizationCost = 0;
unsigned ScalarCalls = 1;
Type *ScalarRetTy = RetTy;
if (RetTy->isVectorTy()) {
ScalarizationCost = getScalarizationOverhead(RetTy, true, false);
ScalarCalls = std::max(ScalarCalls, RetTy->getVectorNumElements());
ScalarRetTy = RetTy->getScalarType();
}
SmallVector<Type *, 4> ScalarTys;
for (unsigned i = 0, ie = Tys.size(); i != ie; ++i) {
Type *Ty = Tys[i];
if (Ty->isVectorTy()) {
ScalarizationCost += getScalarizationOverhead(Ty, false, true);
ScalarCalls = std::max(ScalarCalls, Ty->getVectorNumElements());
Ty = Ty->getScalarType();
}
ScalarTys.push_back(Ty);
}
if (ScalarCalls == 1)
return 1; // Return cost of a scalar intrinsic. Assume it to be cheap.
unsigned ScalarCost = static_cast<T *>(this)->getIntrinsicInstrCost(
IID, ScalarRetTy, ScalarTys, FMF);
return ScalarCalls * ScalarCost + ScalarizationCost;
}
// Look for intrinsics that can be lowered directly or turned into a scalar
// intrinsic call.
case Intrinsic::sqrt:
ISDs.push_back(ISD::FSQRT);
break;
case Intrinsic::sin:
ISDs.push_back(ISD::FSIN);
break;
case Intrinsic::cos:
ISDs.push_back(ISD::FCOS);
break;
case Intrinsic::exp:
ISDs.push_back(ISD::FEXP);
break;
case Intrinsic::exp2:
ISDs.push_back(ISD::FEXP2);
break;
case Intrinsic::log:
ISDs.push_back(ISD::FLOG);
break;
case Intrinsic::log10:
ISDs.push_back(ISD::FLOG10);
break;
case Intrinsic::log2:
ISDs.push_back(ISD::FLOG2);
break;
case Intrinsic::fabs:
ISDs.push_back(ISD::FABS);
break;
case Intrinsic::minnum:
ISDs.push_back(ISD::FMINNUM);
if (FMF.noNaNs())
ISDs.push_back(ISD::FMINNAN);
break;
case Intrinsic::maxnum:
ISDs.push_back(ISD::FMAXNUM);
if (FMF.noNaNs())
ISDs.push_back(ISD::FMAXNAN);
break;
case Intrinsic::copysign:
ISDs.push_back(ISD::FCOPYSIGN);
break;
case Intrinsic::floor:
ISDs.push_back(ISD::FFLOOR);
break;
case Intrinsic::ceil:
ISDs.push_back(ISD::FCEIL);
break;
case Intrinsic::trunc:
ISDs.push_back(ISD::FTRUNC);
break;
case Intrinsic::nearbyint:
ISDs.push_back(ISD::FNEARBYINT);
break;
case Intrinsic::rint:
ISDs.push_back(ISD::FRINT);
break;
case Intrinsic::round:
ISDs.push_back(ISD::FROUND);
break;
case Intrinsic::pow:
ISDs.push_back(ISD::FPOW);
break;
case Intrinsic::fma:
ISDs.push_back(ISD::FMA);
break;
case Intrinsic::fmuladd:
ISDs.push_back(ISD::FMA);
break;
// FIXME: We should return 0 whenever getIntrinsicCost == TCC_Free.
case Intrinsic::lifetime_start:
case Intrinsic::lifetime_end:
return 0;
case Intrinsic::masked_store:
return static_cast<T *>(this)
->getMaskedMemoryOpCost(Instruction::Store, Tys[0], 0, 0);
case Intrinsic::masked_load:
return static_cast<T *>(this)
->getMaskedMemoryOpCost(Instruction::Load, RetTy, 0, 0);
case Intrinsic::ctpop:
ISDs.push_back(ISD::CTPOP);
// In case of legalization use TCC_Expensive. This is cheaper than a
// library call but still not a cheap instruction.
SingleCallCost = TargetTransformInfo::TCC_Expensive;
break;
// FIXME: ctlz, cttz, ...
}
const TargetLoweringBase *TLI = getTLI();
std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(DL, RetTy);
SmallVector<unsigned, 2> LegalCost;
SmallVector<unsigned, 2> CustomCost;
for (unsigned ISD : ISDs) {
if (TLI->isOperationLegalOrPromote(ISD, LT.second)) {
if (IID == Intrinsic::fabs && TLI->isFAbsFree(LT.second)) {
return 0;
}
// The operation is legal. Assume it costs 1.
// If the type is split to multiple registers, assume that there is some
// overhead to this.
// TODO: Once we have extract/insert subvector cost we need to use them.
if (LT.first > 1)
LegalCost.push_back(LT.first * 2);
else
LegalCost.push_back(LT.first * 1);
} else if (!TLI->isOperationExpand(ISD, LT.second)) {
// If the operation is custom lowered then assume
// that the code is twice as expensive.
CustomCost.push_back(LT.first * 2);
}
}
auto MinLegalCostI = std::min_element(LegalCost.begin(), LegalCost.end());
if (MinLegalCostI != LegalCost.end())
return *MinLegalCostI;
auto MinCustomCostI = std::min_element(CustomCost.begin(), CustomCost.end());
if (MinCustomCostI != CustomCost.end())
return *MinCustomCostI;
// If we can't lower fmuladd into an FMA estimate the cost as a floating
// point mul followed by an add.
if (IID == Intrinsic::fmuladd)
return static_cast<T *>(this)
->getArithmeticInstrCost(BinaryOperator::FMul, RetTy) +
static_cast<T *>(this)
->getArithmeticInstrCost(BinaryOperator::FAdd, RetTy);
// Else, assume that we need to scalarize this intrinsic. For math builtins
// this will emit a costly libcall, adding call overhead and spills. Make it
// very expensive.
if (RetTy->isVectorTy()) {
unsigned ScalarizationCost = getScalarizationOverhead(RetTy, true, false);
unsigned ScalarCalls = RetTy->getVectorNumElements();
SmallVector<Type *, 4> ScalarTys;
for (unsigned i = 0, ie = Tys.size(); i != ie; ++i) {
Type *Ty = Tys[i];
if (Ty->isVectorTy())
Ty = Ty->getScalarType();
ScalarTys.push_back(Ty);
}
unsigned ScalarCost = static_cast<T *>(this)->getIntrinsicInstrCost(
IID, RetTy->getScalarType(), ScalarTys, FMF);
for (unsigned i = 0, ie = Tys.size(); i != ie; ++i) {
if (Tys[i]->isVectorTy()) {
ScalarizationCost += getScalarizationOverhead(Tys[i], false, true);
ScalarCalls = std::max(ScalarCalls, Tys[i]->getVectorNumElements());
}
}
return ScalarCalls * ScalarCost + ScalarizationCost;
}
// This is going to be turned into a library call, make it expensive.
return SingleCallCost;
}
/// \brief Compute a cost of the given call instruction.
///
/// Compute the cost of calling function F with return type RetTy and
/// argument types Tys. F might be nullptr, in this case the cost of an
/// arbitrary call with the specified signature will be returned.
/// This is used, for instance, when we estimate call of a vector
/// counterpart of the given function.
/// \param F Called function, might be nullptr.
/// \param RetTy Return value types.
/// \param Tys Argument types.
/// \returns The cost of Call instruction.
unsigned getCallInstrCost(Function *F, Type *RetTy, ArrayRef<Type *> Tys) {
return 10;
}
unsigned getNumberOfParts(Type *Tp) {
std::pair<unsigned, MVT> LT = getTLI()->getTypeLegalizationCost(DL, Tp);
return LT.first;
}
unsigned getAddressComputationCost(Type *Ty, bool IsComplex) { return 0; }
unsigned getReductionCost(unsigned Opcode, Type *Ty, bool IsPairwise) {
assert(Ty->isVectorTy() && "Expect a vector type");
unsigned NumVecElts = Ty->getVectorNumElements();
unsigned NumReduxLevels = Log2_32(NumVecElts);
unsigned ArithCost =
NumReduxLevels *
static_cast<T *>(this)->getArithmeticInstrCost(Opcode, Ty);
// Assume the pairwise shuffles add a cost.
unsigned ShuffleCost =
NumReduxLevels * (IsPairwise + 1) *
static_cast<T *>(this)
->getShuffleCost(TTI::SK_ExtractSubvector, Ty, NumVecElts / 2, Ty);
return ShuffleCost + ArithCost + getScalarizationOverhead(Ty, false, true);
}
/// @}
};
/// \brief Concrete BasicTTIImpl that can be used if no further customization
/// is needed.
class BasicTTIImpl : public BasicTTIImplBase<BasicTTIImpl> {
typedef BasicTTIImplBase<BasicTTIImpl> BaseT;
friend class BasicTTIImplBase<BasicTTIImpl>;
const TargetSubtargetInfo *ST;
const TargetLoweringBase *TLI;
const TargetSubtargetInfo *getST() const { return ST; }
const TargetLoweringBase *getTLI() const { return TLI; }
public:
explicit BasicTTIImpl(const TargetMachine *ST, const Function &F);
// Provide value semantics. MSVC requires that we spell all of these out.
BasicTTIImpl(const BasicTTIImpl &Arg)
: BaseT(static_cast<const BaseT &>(Arg)), ST(Arg.ST), TLI(Arg.TLI) {}
BasicTTIImpl(BasicTTIImpl &&Arg)
: BaseT(std::move(static_cast<BaseT &>(Arg))), ST(std::move(Arg.ST)),
TLI(std::move(Arg.TLI)) {}
};
}
#endif
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