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llvm-mirror/include/llvm/CodeGen/BasicTTIImpl.h
Jonas Paulsson 6ae041f182 [LoopStrenghtReduce] Refactoring and addition of a new target cost function. 
Refactored so that a LSRUse owns its fixups, as oppsed to letting the
LSRInstance own them. This makes it easier to rate formulas for
LSRUses, since the fixups are available directly. The Offsets vector
has been removed since it was no longer necessary.

New target hook isFoldableMemAccessOffset(), which is used during formula
rating.

For SystemZ, this is useful to express that loads and stores with
float or vector types with a big/negative offset should be avoided in
loops. Without this, LSR will generate a lot of negative offsets that
would require extra instructions for loading the address.

Updated tests:
test/CodeGen/SystemZ/loop-01.ll

Reviewed by: Quentin Colombet and Ulrich Weigand.
https://reviews.llvm.org/D19152

llvm-svn: 278927
2016-08-17 13:24:19 +00:00

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36 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 allowsMisalignedMemoryAccesses(LLVMContext &Context,
unsigned BitWidth, unsigned AddressSpace,
unsigned Alignment, bool *Fast) const {
EVT E = EVT::getIntegerVT(Context, BitWidth);
return getTLI()->allowsMisalignedMemoryAccesses(E, AddressSpace, Alignment, Fast);
}
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 isFoldableMemAccessOffset(Instruction *I, int64_t Offset) {
return getTLI()->isFoldableMemAccessOffset(I, Offset);
}
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);
}
int getGEPCost(Type *PointeeType, const Value *Ptr,
ArrayRef<const Value *> Operands) {
return BaseT::getGEPCost(PointeeType, Ptr, Operands);
}
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.
// TODO: If one of the types get legalized by splitting, handle this
// similarly to what getCastInstrCost() does.
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 legalizing by splitting, query the concrete TTI for the cost
// of casting the original vector twice. We also need to factor int the
// cost of the split itself. Count that as 1, to be consistent with
// TLI->getTypeLegalizationCost().
if ((TLI->getTypeAction(Src->getContext(), TLI->getValueType(DL, Src)) ==
TargetLowering::TypeSplitVector) ||
(TLI->getTypeAction(Dst->getContext(), TLI->getValueType(DL, Dst)) ==
TargetLowering::TypeSplitVector)) {
Type *SplitDst = VectorType::get(Dst->getVectorElementType(),
Dst->getVectorNumElements() / 2);
Type *SplitSrc = VectorType::get(Src->getVectorElementType(),
Src->getVectorNumElements() / 2);
T *TTI = static_cast<T *>(this);
return TTI->getVectorSplitCost() +
(2 * TTI->getCastInstrCost(Opcode, SplitDst, SplitSrc));
}
// In other cases where the source or destination are illegal, assume
// the operation will get scalarized.
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.
// TODO: If one of the types get legalized by splitting, handle this
// similarly to what getCastInstrCost() does.
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);
}
unsigned getVectorSplitCost() { return 1; }
/// @}
};
/// \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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