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llvm-project/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp

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//===- ARMTargetTransformInfo.cpp - ARM specific TTI ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "ARMTargetTransformInfo.h"
#include "ARMSubtarget.h"
#include "MCTargetDesc/ARMAddressingModes.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/CodeGen/CostTable.h"
#include "llvm/CodeGen/ISDOpcodes.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Type.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/MachineValueType.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <utility>
using namespace llvm;
#define DEBUG_TYPE "armtti"
bool ARMTTIImpl::areInlineCompatible(const Function *Caller,
const Function *Callee) const {
const TargetMachine &TM = getTLI()->getTargetMachine();
const FeatureBitset &CallerBits =
TM.getSubtargetImpl(*Caller)->getFeatureBits();
const FeatureBitset &CalleeBits =
TM.getSubtargetImpl(*Callee)->getFeatureBits();
// To inline a callee, all features not in the whitelist must match exactly.
bool MatchExact = (CallerBits & ~InlineFeatureWhitelist) ==
(CalleeBits & ~InlineFeatureWhitelist);
// For features in the whitelist, the callee's features must be a subset of
// the callers'.
bool MatchSubset = ((CallerBits & CalleeBits) & InlineFeatureWhitelist) ==
(CalleeBits & InlineFeatureWhitelist);
return MatchExact && MatchSubset;
}
int ARMTTIImpl::getIntImmCost(const APInt &Imm, Type *Ty) {
assert(Ty->isIntegerTy());
unsigned Bits = Ty->getPrimitiveSizeInBits();
if (Bits == 0 || Imm.getActiveBits() >= 64)
return 4;
int64_t SImmVal = Imm.getSExtValue();
uint64_t ZImmVal = Imm.getZExtValue();
if (!ST->isThumb()) {
if ((SImmVal >= 0 && SImmVal < 65536) ||
(ARM_AM::getSOImmVal(ZImmVal) != -1) ||
(ARM_AM::getSOImmVal(~ZImmVal) != -1))
return 1;
return ST->hasV6T2Ops() ? 2 : 3;
}
if (ST->isThumb2()) {
if ((SImmVal >= 0 && SImmVal < 65536) ||
(ARM_AM::getT2SOImmVal(ZImmVal) != -1) ||
(ARM_AM::getT2SOImmVal(~ZImmVal) != -1))
return 1;
return ST->hasV6T2Ops() ? 2 : 3;
}
// Thumb1.
if (SImmVal >= 0 && SImmVal < 256)
return 1;
if ((~SImmVal < 256) || ARM_AM::isThumbImmShiftedVal(ZImmVal))
return 2;
// Load from constantpool.
return 3;
}
// Constants smaller than 256 fit in the immediate field of
// Thumb1 instructions so we return a zero cost and 1 otherwise.
int ARMTTIImpl::getIntImmCodeSizeCost(unsigned Opcode, unsigned Idx,
const APInt &Imm, Type *Ty) {
if (Imm.isNonNegative() && Imm.getLimitedValue() < 256)
return 0;
return 1;
}
int ARMTTIImpl::getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
Type *Ty) {
// Division by a constant can be turned into multiplication, but only if we
// know it's constant. So it's not so much that the immediate is cheap (it's
// not), but that the alternative is worse.
// FIXME: this is probably unneeded with GlobalISel.
if ((Opcode == Instruction::SDiv || Opcode == Instruction::UDiv ||
Opcode == Instruction::SRem || Opcode == Instruction::URem) &&
Idx == 1)
return 0;
if (Opcode == Instruction::And)
// Conversion to BIC is free, and means we can use ~Imm instead.
return std::min(getIntImmCost(Imm, Ty), getIntImmCost(~Imm, Ty));
if (Opcode == Instruction::Add)
// Conversion to SUB is free, and means we can use -Imm instead.
return std::min(getIntImmCost(Imm, Ty), getIntImmCost(-Imm, Ty));
if (Opcode == Instruction::ICmp && Imm.isNegative() &&
Ty->getIntegerBitWidth() == 32) {
int64_t NegImm = -Imm.getSExtValue();
if (ST->isThumb2() && NegImm < 1<<12)
// icmp X, #-C -> cmn X, #C
return 0;
if (ST->isThumb() && NegImm < 1<<8)
// icmp X, #-C -> adds X, #C
return 0;
}
// xor a, -1 can always be folded to MVN
if (Opcode == Instruction::Xor && Imm.isAllOnesValue())
return 0;
return getIntImmCost(Imm, Ty);
}
int ARMTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src,
const Instruction *I) {
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
// Single to/from double precision conversions.
static const CostTblEntry NEONFltDblTbl[] = {
// Vector fptrunc/fpext conversions.
{ ISD::FP_ROUND, MVT::v2f64, 2 },
{ ISD::FP_EXTEND, MVT::v2f32, 2 },
{ ISD::FP_EXTEND, MVT::v4f32, 4 }
};
if (Src->isVectorTy() && ST->hasNEON() && (ISD == ISD::FP_ROUND ||
ISD == ISD::FP_EXTEND)) {
std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, Src);
if (const auto *Entry = CostTableLookup(NEONFltDblTbl, ISD, LT.second))
return LT.first * Entry->Cost;
}
EVT SrcTy = TLI->getValueType(DL, Src);
EVT DstTy = TLI->getValueType(DL, Dst);
if (!SrcTy.isSimple() || !DstTy.isSimple())
return BaseT::getCastInstrCost(Opcode, Dst, Src);
// Some arithmetic, load and store operations have specific instructions
// to cast up/down their types automatically at no extra cost.
// TODO: Get these tables to know at least what the related operations are.
static const TypeConversionCostTblEntry NEONVectorConversionTbl[] = {
{ ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i16, 0 },
{ ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i16, 0 },
{ ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i32, 1 },
{ ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i32, 1 },
{ ISD::TRUNCATE, MVT::v4i32, MVT::v4i64, 0 },
{ ISD::TRUNCATE, MVT::v4i16, MVT::v4i32, 1 },
// The number of vmovl instructions for the extension.
{ ISD::SIGN_EXTEND, MVT::v4i64, MVT::v4i16, 3 },
{ ISD::ZERO_EXTEND, MVT::v4i64, MVT::v4i16, 3 },
{ ISD::SIGN_EXTEND, MVT::v8i32, MVT::v8i8, 3 },
{ ISD::ZERO_EXTEND, MVT::v8i32, MVT::v8i8, 3 },
{ ISD::SIGN_EXTEND, MVT::v8i64, MVT::v8i8, 7 },
{ ISD::ZERO_EXTEND, MVT::v8i64, MVT::v8i8, 7 },
{ ISD::SIGN_EXTEND, MVT::v8i64, MVT::v8i16, 6 },
{ ISD::ZERO_EXTEND, MVT::v8i64, MVT::v8i16, 6 },
{ ISD::SIGN_EXTEND, MVT::v16i32, MVT::v16i8, 6 },
{ ISD::ZERO_EXTEND, MVT::v16i32, MVT::v16i8, 6 },
// Operations that we legalize using splitting.
{ ISD::TRUNCATE, MVT::v16i8, MVT::v16i32, 6 },
{ ISD::TRUNCATE, MVT::v8i8, MVT::v8i32, 3 },
// Vector float <-> i32 conversions.
{ ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 },
{ ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 },
{ ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i8, 3 },
{ ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i8, 3 },
{ ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i16, 2 },
{ ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i16, 2 },
{ ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i32, 1 },
{ ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i32, 1 },
{ ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i1, 3 },
{ ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i1, 3 },
{ ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i8, 3 },
{ ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i8, 3 },
{ ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 },
{ ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 },
{ ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i16, 4 },
{ ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i16, 4 },
{ ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i32, 2 },
{ ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i32, 2 },
{ ISD::SINT_TO_FP, MVT::v16f32, MVT::v16i16, 8 },
{ ISD::UINT_TO_FP, MVT::v16f32, MVT::v16i16, 8 },
{ ISD::SINT_TO_FP, MVT::v16f32, MVT::v16i32, 4 },
{ ISD::UINT_TO_FP, MVT::v16f32, MVT::v16i32, 4 },
{ ISD::FP_TO_SINT, MVT::v4i32, MVT::v4f32, 1 },
{ ISD::FP_TO_UINT, MVT::v4i32, MVT::v4f32, 1 },
{ ISD::FP_TO_SINT, MVT::v4i8, MVT::v4f32, 3 },
{ ISD::FP_TO_UINT, MVT::v4i8, MVT::v4f32, 3 },
{ ISD::FP_TO_SINT, MVT::v4i16, MVT::v4f32, 2 },
{ ISD::FP_TO_UINT, MVT::v4i16, MVT::v4f32, 2 },
// Vector double <-> i32 conversions.
{ ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 },
{ ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 },
{ ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i8, 4 },
{ ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i8, 4 },
{ ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i16, 3 },
{ ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i16, 3 },
{ ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 },
{ ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 },
{ ISD::FP_TO_SINT, MVT::v2i32, MVT::v2f64, 2 },
{ ISD::FP_TO_UINT, MVT::v2i32, MVT::v2f64, 2 },
{ ISD::FP_TO_SINT, MVT::v8i16, MVT::v8f32, 4 },
{ ISD::FP_TO_UINT, MVT::v8i16, MVT::v8f32, 4 },
{ ISD::FP_TO_SINT, MVT::v16i16, MVT::v16f32, 8 },
{ ISD::FP_TO_UINT, MVT::v16i16, MVT::v16f32, 8 }
};
if (SrcTy.isVector() && ST->hasNEON()) {
if (const auto *Entry = ConvertCostTableLookup(NEONVectorConversionTbl, ISD,
DstTy.getSimpleVT(),
SrcTy.getSimpleVT()))
return Entry->Cost;
}
// Scalar float to integer conversions.
static const TypeConversionCostTblEntry NEONFloatConversionTbl[] = {
{ ISD::FP_TO_SINT, MVT::i1, MVT::f32, 2 },
{ ISD::FP_TO_UINT, MVT::i1, MVT::f32, 2 },
{ ISD::FP_TO_SINT, MVT::i1, MVT::f64, 2 },
{ ISD::FP_TO_UINT, MVT::i1, MVT::f64, 2 },
{ ISD::FP_TO_SINT, MVT::i8, MVT::f32, 2 },
{ ISD::FP_TO_UINT, MVT::i8, MVT::f32, 2 },
{ ISD::FP_TO_SINT, MVT::i8, MVT::f64, 2 },
{ ISD::FP_TO_UINT, MVT::i8, MVT::f64, 2 },
{ ISD::FP_TO_SINT, MVT::i16, MVT::f32, 2 },
{ ISD::FP_TO_UINT, MVT::i16, MVT::f32, 2 },
{ ISD::FP_TO_SINT, MVT::i16, MVT::f64, 2 },
{ ISD::FP_TO_UINT, MVT::i16, MVT::f64, 2 },
{ ISD::FP_TO_SINT, MVT::i32, MVT::f32, 2 },
{ ISD::FP_TO_UINT, MVT::i32, MVT::f32, 2 },
{ ISD::FP_TO_SINT, MVT::i32, MVT::f64, 2 },
{ ISD::FP_TO_UINT, MVT::i32, MVT::f64, 2 },
{ ISD::FP_TO_SINT, MVT::i64, MVT::f32, 10 },
{ ISD::FP_TO_UINT, MVT::i64, MVT::f32, 10 },
{ ISD::FP_TO_SINT, MVT::i64, MVT::f64, 10 },
{ ISD::FP_TO_UINT, MVT::i64, MVT::f64, 10 }
};
if (SrcTy.isFloatingPoint() && ST->hasNEON()) {
if (const auto *Entry = ConvertCostTableLookup(NEONFloatConversionTbl, ISD,
DstTy.getSimpleVT(),
SrcTy.getSimpleVT()))
return Entry->Cost;
}
// Scalar integer to float conversions.
static const TypeConversionCostTblEntry NEONIntegerConversionTbl[] = {
{ ISD::SINT_TO_FP, MVT::f32, MVT::i1, 2 },
{ ISD::UINT_TO_FP, MVT::f32, MVT::i1, 2 },
{ ISD::SINT_TO_FP, MVT::f64, MVT::i1, 2 },
{ ISD::UINT_TO_FP, MVT::f64, MVT::i1, 2 },
{ ISD::SINT_TO_FP, MVT::f32, MVT::i8, 2 },
{ ISD::UINT_TO_FP, MVT::f32, MVT::i8, 2 },
{ ISD::SINT_TO_FP, MVT::f64, MVT::i8, 2 },
{ ISD::UINT_TO_FP, MVT::f64, MVT::i8, 2 },
{ ISD::SINT_TO_FP, MVT::f32, MVT::i16, 2 },
{ ISD::UINT_TO_FP, MVT::f32, MVT::i16, 2 },
{ ISD::SINT_TO_FP, MVT::f64, MVT::i16, 2 },
{ ISD::UINT_TO_FP, MVT::f64, MVT::i16, 2 },
{ ISD::SINT_TO_FP, MVT::f32, MVT::i32, 2 },
{ ISD::UINT_TO_FP, MVT::f32, MVT::i32, 2 },
{ ISD::SINT_TO_FP, MVT::f64, MVT::i32, 2 },
{ ISD::UINT_TO_FP, MVT::f64, MVT::i32, 2 },
{ ISD::SINT_TO_FP, MVT::f32, MVT::i64, 10 },
{ ISD::UINT_TO_FP, MVT::f32, MVT::i64, 10 },
{ ISD::SINT_TO_FP, MVT::f64, MVT::i64, 10 },
{ ISD::UINT_TO_FP, MVT::f64, MVT::i64, 10 }
};
if (SrcTy.isInteger() && ST->hasNEON()) {
if (const auto *Entry = ConvertCostTableLookup(NEONIntegerConversionTbl,
ISD, DstTy.getSimpleVT(),
SrcTy.getSimpleVT()))
return Entry->Cost;
}
// Scalar integer conversion costs.
static const TypeConversionCostTblEntry ARMIntegerConversionTbl[] = {
// i16 -> i64 requires two dependent operations.
{ ISD::SIGN_EXTEND, MVT::i64, MVT::i16, 2 },
// Truncates on i64 are assumed to be free.
{ ISD::TRUNCATE, MVT::i32, MVT::i64, 0 },
{ ISD::TRUNCATE, MVT::i16, MVT::i64, 0 },
{ ISD::TRUNCATE, MVT::i8, MVT::i64, 0 },
{ ISD::TRUNCATE, MVT::i1, MVT::i64, 0 }
};
if (SrcTy.isInteger()) {
if (const auto *Entry = ConvertCostTableLookup(ARMIntegerConversionTbl, ISD,
DstTy.getSimpleVT(),
SrcTy.getSimpleVT()))
return Entry->Cost;
}
return BaseT::getCastInstrCost(Opcode, Dst, Src);
}
int ARMTTIImpl::getVectorInstrCost(unsigned Opcode, Type *ValTy,
unsigned Index) {
// Penalize inserting into an D-subregister. We end up with a three times
// lower estimated throughput on swift.
if (ST->hasSlowLoadDSubregister() && Opcode == Instruction::InsertElement &&
ValTy->isVectorTy() && ValTy->getScalarSizeInBits() <= 32)
return 3;
if ((Opcode == Instruction::InsertElement ||
Opcode == Instruction::ExtractElement)) {
// Cross-class copies are expensive on many microarchitectures,
// so assume they are expensive by default.
if (ValTy->getVectorElementType()->isIntegerTy())
return 3;
// Even if it's not a cross class copy, this likely leads to mixing
// of NEON and VFP code and should be therefore penalized.
if (ValTy->isVectorTy() &&
ValTy->getScalarSizeInBits() <= 32)
return std::max(BaseT::getVectorInstrCost(Opcode, ValTy, Index), 2U);
}
return BaseT::getVectorInstrCost(Opcode, ValTy, Index);
}
int ARMTTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy,
const Instruction *I) {
int ISD = TLI->InstructionOpcodeToISD(Opcode);
// On NEON a vector select gets lowered to vbsl.
if (ST->hasNEON() && ValTy->isVectorTy() && ISD == ISD::SELECT) {
// Lowering of some vector selects is currently far from perfect.
static const TypeConversionCostTblEntry NEONVectorSelectTbl[] = {
{ ISD::SELECT, MVT::v4i1, MVT::v4i64, 4*4 + 1*2 + 1 },
{ ISD::SELECT, MVT::v8i1, MVT::v8i64, 50 },
{ ISD::SELECT, MVT::v16i1, MVT::v16i64, 100 }
};
EVT SelCondTy = TLI->getValueType(DL, CondTy);
EVT SelValTy = TLI->getValueType(DL, ValTy);
if (SelCondTy.isSimple() && SelValTy.isSimple()) {
if (const auto *Entry = ConvertCostTableLookup(NEONVectorSelectTbl, ISD,
SelCondTy.getSimpleVT(),
SelValTy.getSimpleVT()))
return Entry->Cost;
}
std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, ValTy);
return LT.first;
}
return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, I);
}
int ARMTTIImpl::getAddressComputationCost(Type *Ty, ScalarEvolution *SE,
const SCEV *Ptr) {
// Address computations in vectorized code with non-consecutive addresses will
// likely result in more instructions compared to scalar code where the
// computation can more often be merged into the index mode. The resulting
// extra micro-ops can significantly decrease throughput.
unsigned NumVectorInstToHideOverhead = 10;
int MaxMergeDistance = 64;
if (Ty->isVectorTy() && SE &&
!BaseT::isConstantStridedAccessLessThan(SE, Ptr, MaxMergeDistance + 1))
return NumVectorInstToHideOverhead;
// In many cases the address computation is not merged into the instruction
// addressing mode.
return 1;
}
int ARMTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, int Index,
Type *SubTp) {
// We only handle costs of reverse and select shuffles for now.
if (Kind != TTI::SK_Reverse && Kind != TTI::SK_Select)
return BaseT::getShuffleCost(Kind, Tp, Index, SubTp);
if (Kind == TTI::SK_Reverse) {
static const CostTblEntry NEONShuffleTbl[] = {
// Reverse shuffle cost one instruction if we are shuffling within a
// double word (vrev) or two if we shuffle a quad word (vrev, vext).
{ISD::VECTOR_SHUFFLE, MVT::v2i32, 1},
{ISD::VECTOR_SHUFFLE, MVT::v2f32, 1},
{ISD::VECTOR_SHUFFLE, MVT::v2i64, 1},
{ISD::VECTOR_SHUFFLE, MVT::v2f64, 1},
{ISD::VECTOR_SHUFFLE, MVT::v4i32, 2},
{ISD::VECTOR_SHUFFLE, MVT::v4f32, 2},
{ISD::VECTOR_SHUFFLE, MVT::v8i16, 2},
{ISD::VECTOR_SHUFFLE, MVT::v16i8, 2}};
std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, Tp);
if (const auto *Entry = CostTableLookup(NEONShuffleTbl, ISD::VECTOR_SHUFFLE,
LT.second))
return LT.first * Entry->Cost;
return BaseT::getShuffleCost(Kind, Tp, Index, SubTp);
}
if (Kind == TTI::SK_Select) {
static const CostTblEntry NEONSelShuffleTbl[] = {
// Select shuffle cost table for ARM. Cost is the number of instructions
// required to create the shuffled vector.
{ISD::VECTOR_SHUFFLE, MVT::v2f32, 1},
{ISD::VECTOR_SHUFFLE, MVT::v2i64, 1},
{ISD::VECTOR_SHUFFLE, MVT::v2f64, 1},
{ISD::VECTOR_SHUFFLE, MVT::v2i32, 1},
{ISD::VECTOR_SHUFFLE, MVT::v4i32, 2},
{ISD::VECTOR_SHUFFLE, MVT::v4f32, 2},
{ISD::VECTOR_SHUFFLE, MVT::v4i16, 2},
{ISD::VECTOR_SHUFFLE, MVT::v8i16, 16},
{ISD::VECTOR_SHUFFLE, MVT::v16i8, 32}};
std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, Tp);
if (const auto *Entry = CostTableLookup(NEONSelShuffleTbl,
ISD::VECTOR_SHUFFLE, LT.second))
return LT.first * Entry->Cost;
return BaseT::getShuffleCost(Kind, Tp, Index, SubTp);
}
return BaseT::getShuffleCost(Kind, Tp, Index, SubTp);
}
int ARMTTIImpl::getArithmeticInstrCost(
unsigned Opcode, Type *Ty, TTI::OperandValueKind Op1Info,
TTI::OperandValueKind Op2Info, TTI::OperandValueProperties Opd1PropInfo,
TTI::OperandValueProperties Opd2PropInfo,
ArrayRef<const Value *> Args) {
int ISDOpcode = TLI->InstructionOpcodeToISD(Opcode);
std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, Ty);
const unsigned FunctionCallDivCost = 20;
const unsigned ReciprocalDivCost = 10;
static const CostTblEntry CostTbl[] = {
// Division.
// These costs are somewhat random. Choose a cost of 20 to indicate that
// vectorizing devision (added function call) is going to be very expensive.
// Double registers types.
{ ISD::SDIV, MVT::v1i64, 1 * FunctionCallDivCost},
{ ISD::UDIV, MVT::v1i64, 1 * FunctionCallDivCost},
{ ISD::SREM, MVT::v1i64, 1 * FunctionCallDivCost},
{ ISD::UREM, MVT::v1i64, 1 * FunctionCallDivCost},
{ ISD::SDIV, MVT::v2i32, 2 * FunctionCallDivCost},
{ ISD::UDIV, MVT::v2i32, 2 * FunctionCallDivCost},
{ ISD::SREM, MVT::v2i32, 2 * FunctionCallDivCost},
{ ISD::UREM, MVT::v2i32, 2 * FunctionCallDivCost},
{ ISD::SDIV, MVT::v4i16, ReciprocalDivCost},
{ ISD::UDIV, MVT::v4i16, ReciprocalDivCost},
{ ISD::SREM, MVT::v4i16, 4 * FunctionCallDivCost},
{ ISD::UREM, MVT::v4i16, 4 * FunctionCallDivCost},
{ ISD::SDIV, MVT::v8i8, ReciprocalDivCost},
{ ISD::UDIV, MVT::v8i8, ReciprocalDivCost},
{ ISD::SREM, MVT::v8i8, 8 * FunctionCallDivCost},
{ ISD::UREM, MVT::v8i8, 8 * FunctionCallDivCost},
// Quad register types.
{ ISD::SDIV, MVT::v2i64, 2 * FunctionCallDivCost},
{ ISD::UDIV, MVT::v2i64, 2 * FunctionCallDivCost},
{ ISD::SREM, MVT::v2i64, 2 * FunctionCallDivCost},
{ ISD::UREM, MVT::v2i64, 2 * FunctionCallDivCost},
{ ISD::SDIV, MVT::v4i32, 4 * FunctionCallDivCost},
{ ISD::UDIV, MVT::v4i32, 4 * FunctionCallDivCost},
{ ISD::SREM, MVT::v4i32, 4 * FunctionCallDivCost},
{ ISD::UREM, MVT::v4i32, 4 * FunctionCallDivCost},
{ ISD::SDIV, MVT::v8i16, 8 * FunctionCallDivCost},
{ ISD::UDIV, MVT::v8i16, 8 * FunctionCallDivCost},
{ ISD::SREM, MVT::v8i16, 8 * FunctionCallDivCost},
{ ISD::UREM, MVT::v8i16, 8 * FunctionCallDivCost},
{ ISD::SDIV, MVT::v16i8, 16 * FunctionCallDivCost},
{ ISD::UDIV, MVT::v16i8, 16 * FunctionCallDivCost},
{ ISD::SREM, MVT::v16i8, 16 * FunctionCallDivCost},
{ ISD::UREM, MVT::v16i8, 16 * FunctionCallDivCost},
// Multiplication.
};
if (ST->hasNEON())
if (const auto *Entry = CostTableLookup(CostTbl, ISDOpcode, LT.second))
return LT.first * Entry->Cost;
int Cost = BaseT::getArithmeticInstrCost(Opcode, Ty, Op1Info, Op2Info,
Opd1PropInfo, Opd2PropInfo);
// This is somewhat of a hack. The problem that we are facing is that SROA
// creates a sequence of shift, and, or instructions to construct values.
// These sequences are recognized by the ISel and have zero-cost. Not so for
// the vectorized code. Because we have support for v2i64 but not i64 those
// sequences look particularly beneficial to vectorize.
// To work around this we increase the cost of v2i64 operations to make them
// seem less beneficial.
if (LT.second == MVT::v2i64 &&
Op2Info == TargetTransformInfo::OK_UniformConstantValue)
Cost += 4;
return Cost;
}
int ARMTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace, const Instruction *I) {
std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, Src);
if (Src->isVectorTy() && Alignment != 16 &&
Src->getVectorElementType()->isDoubleTy()) {
// Unaligned loads/stores are extremely inefficient.
// We need 4 uops for vst.1/vld.1 vs 1uop for vldr/vstr.
return LT.first * 4;
}
return LT.first;
}
int ARMTTIImpl::getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
unsigned Factor,
ArrayRef<unsigned> Indices,
unsigned Alignment,
unsigned AddressSpace) {
assert(Factor >= 2 && "Invalid interleave factor");
assert(isa<VectorType>(VecTy) && "Expect a vector type");
// vldN/vstN doesn't support vector types of i64/f64 element.
bool EltIs64Bits = DL.getTypeSizeInBits(VecTy->getScalarType()) == 64;
if (Factor <= TLI->getMaxSupportedInterleaveFactor() && !EltIs64Bits) {
unsigned NumElts = VecTy->getVectorNumElements();
auto *SubVecTy = VectorType::get(VecTy->getScalarType(), NumElts / Factor);
// vldN/vstN only support legal vector types of size 64 or 128 in bits.
// Accesses having vector types that are a multiple of 128 bits can be
// matched to more than one vldN/vstN instruction.
if (NumElts % Factor == 0 &&
TLI->isLegalInterleavedAccessType(SubVecTy, DL))
return Factor * TLI->getNumInterleavedAccesses(SubVecTy, DL);
}
return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices,
Alignment, AddressSpace);
}
void ARMTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
TTI::UnrollingPreferences &UP) {
// Only currently enable these preferences for M-Class cores.
if (!ST->isMClass())
return BasicTTIImplBase::getUnrollingPreferences(L, SE, UP);
// Disable loop unrolling for Oz and Os.
UP.OptSizeThreshold = 0;
UP.PartialOptSizeThreshold = 0;
if (L->getHeader()->getParent()->optForSize())
return;
// Only enable on Thumb-2 targets.
if (!ST->isThumb2())
return;
SmallVector<BasicBlock*, 4> ExitingBlocks;
L->getExitingBlocks(ExitingBlocks);
LLVM_DEBUG(dbgs() << "Loop has:\n"
<< "Blocks: " << L->getNumBlocks() << "\n"
<< "Exit blocks: " << ExitingBlocks.size() << "\n");
// Only allow another exit other than the latch. This acts as an early exit
// as it mirrors the profitability calculation of the runtime unroller.
if (ExitingBlocks.size() > 2)
return;
// Limit the CFG of the loop body for targets with a branch predictor.
// Allowing 4 blocks permits if-then-else diamonds in the body.
if (ST->hasBranchPredictor() && L->getNumBlocks() > 4)
return;
// Scan the loop: don't unroll loops with calls as this could prevent
// inlining.
unsigned Cost = 0;
for (auto *BB : L->getBlocks()) {
for (auto &I : *BB) {
if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
ImmutableCallSite CS(&I);
if (const Function *F = CS.getCalledFunction()) {
if (!isLoweredToCall(F))
continue;
}
return;
}
SmallVector<const Value*, 4> Operands(I.value_op_begin(),
I.value_op_end());
Cost += getUserCost(&I, Operands);
}
}
LLVM_DEBUG(dbgs() << "Cost of loop: " << Cost << "\n");
UP.Partial = true;
UP.Runtime = true;
UP.UnrollRemainder = true;
UP.DefaultUnrollRuntimeCount = 4;
UP.UnrollAndJam = true;
UP.UnrollAndJamInnerLoopThreshold = 60;
// Force unrolling small loops can be very useful because of the branch
// taken cost of the backedge.
if (Cost < 12)
UP.Force = true;
}
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