llvm-6502/lib/CodeGen/BasicTargetTransformInfo.cpp
Arnold Schwaighofer fb55a8fd7c ARM cost model: Address computation in vector mem ops not free
Adds a function to target transform info to query for the cost of address
computation. The cost model analysis pass now also queries this interface.
The code in LoopVectorize adds the cost of address computation as part of the
memory instruction cost calculation. Only there, we know whether the instruction
will be scalarized or not.
Increase the penality for inserting in to D registers on swift. This becomes
necessary because we now always assume that address computation has a cost and
three is a closer value to the architecture.

radar://13097204

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174713 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-08 14:50:48 +00:00

408 lines
14 KiB
C++

//===- BasicTargetTransformInfo.cpp - Basic target-independent TTI impl ---===//
//
// 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 the implementation of a basic TargetTransformInfo pass
/// predicated on the target abstractions present in the target independent
/// code generator. It uses these (primarily TargetLowering) to model as much
/// of the TTI query interface as possible. It is included by most targets so
/// that they can specialize only a small subset of the query space.
///
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "basictti"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Target/TargetLowering.h"
#include <utility>
using namespace llvm;
namespace {
class BasicTTI : public ImmutablePass, public TargetTransformInfo {
const TargetLoweringBase *TLI;
/// 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) const;
public:
BasicTTI() : ImmutablePass(ID), TLI(0) {
llvm_unreachable("This pass cannot be directly constructed");
}
BasicTTI(const TargetLoweringBase *TLI) : ImmutablePass(ID), TLI(TLI) {
initializeBasicTTIPass(*PassRegistry::getPassRegistry());
}
virtual void initializePass() {
pushTTIStack(this);
}
virtual void finalizePass() {
popTTIStack();
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
TargetTransformInfo::getAnalysisUsage(AU);
}
/// Pass identification.
static char ID;
/// Provide necessary pointer adjustments for the two base classes.
virtual void *getAdjustedAnalysisPointer(const void *ID) {
if (ID == &TargetTransformInfo::ID)
return (TargetTransformInfo*)this;
return this;
}
/// \name Scalar TTI Implementations
/// @{
virtual bool isLegalAddImmediate(int64_t imm) const;
virtual bool isLegalICmpImmediate(int64_t imm) const;
virtual bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
int64_t BaseOffset, bool HasBaseReg,
int64_t Scale) const;
virtual bool isTruncateFree(Type *Ty1, Type *Ty2) const;
virtual bool isTypeLegal(Type *Ty) const;
virtual unsigned getJumpBufAlignment() const;
virtual unsigned getJumpBufSize() const;
virtual bool shouldBuildLookupTables() const;
/// @}
/// \name Vector TTI Implementations
/// @{
virtual unsigned getNumberOfRegisters(bool Vector) const;
virtual unsigned getMaximumUnrollFactor() const;
virtual unsigned getRegisterBitWidth(bool Vector) const;
virtual unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty) const;
virtual unsigned getShuffleCost(ShuffleKind Kind, Type *Tp,
int Index, Type *SubTp) const;
virtual unsigned getCastInstrCost(unsigned Opcode, Type *Dst,
Type *Src) const;
virtual unsigned getCFInstrCost(unsigned Opcode) const;
virtual unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
Type *CondTy) const;
virtual unsigned getVectorInstrCost(unsigned Opcode, Type *Val,
unsigned Index) const;
virtual unsigned getMemoryOpCost(unsigned Opcode, Type *Src,
unsigned Alignment,
unsigned AddressSpace) const;
virtual unsigned getIntrinsicInstrCost(Intrinsic::ID, Type *RetTy,
ArrayRef<Type*> Tys) const;
virtual unsigned getNumberOfParts(Type *Tp) const;
virtual unsigned getAddressComputationCost(Type *Ty) const;
/// @}
};
}
INITIALIZE_AG_PASS(BasicTTI, TargetTransformInfo, "basictti",
"Target independent code generator's TTI", true, true, false)
char BasicTTI::ID = 0;
ImmutablePass *
llvm::createBasicTargetTransformInfoPass(const TargetLoweringBase *TLI) {
return new BasicTTI(TLI);
}
bool BasicTTI::isLegalAddImmediate(int64_t imm) const {
return TLI->isLegalAddImmediate(imm);
}
bool BasicTTI::isLegalICmpImmediate(int64_t imm) const {
return TLI->isLegalICmpImmediate(imm);
}
bool BasicTTI::isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
int64_t BaseOffset, bool HasBaseReg,
int64_t Scale) const {
TargetLoweringBase::AddrMode AM;
AM.BaseGV = BaseGV;
AM.BaseOffs = BaseOffset;
AM.HasBaseReg = HasBaseReg;
AM.Scale = Scale;
return TLI->isLegalAddressingMode(AM, Ty);
}
bool BasicTTI::isTruncateFree(Type *Ty1, Type *Ty2) const {
return TLI->isTruncateFree(Ty1, Ty2);
}
bool BasicTTI::isTypeLegal(Type *Ty) const {
EVT T = TLI->getValueType(Ty);
return TLI->isTypeLegal(T);
}
unsigned BasicTTI::getJumpBufAlignment() const {
return TLI->getJumpBufAlignment();
}
unsigned BasicTTI::getJumpBufSize() const {
return TLI->getJumpBufSize();
}
bool BasicTTI::shouldBuildLookupTables() const {
return TLI->supportJumpTables() &&
(TLI->isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
TLI->isOperationLegalOrCustom(ISD::BRIND, MVT::Other));
}
//===----------------------------------------------------------------------===//
//
// Calls used by the vectorizers.
//
//===----------------------------------------------------------------------===//
unsigned BasicTTI::getScalarizationOverhead(Type *Ty, bool Insert,
bool Extract) const {
assert (Ty->isVectorTy() && "Can only scalarize vectors");
unsigned Cost = 0;
for (int i = 0, e = Ty->getVectorNumElements(); i < e; ++i) {
if (Insert)
Cost += TopTTI->getVectorInstrCost(Instruction::InsertElement, Ty, i);
if (Extract)
Cost += TopTTI->getVectorInstrCost(Instruction::ExtractElement, Ty, i);
}
return Cost;
}
unsigned BasicTTI::getNumberOfRegisters(bool Vector) const {
return 1;
}
unsigned BasicTTI::getRegisterBitWidth(bool Vector) const {
return 32;
}
unsigned BasicTTI::getMaximumUnrollFactor() const {
return 1;
}
unsigned BasicTTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty) const {
// Check if any of the operands are vector operands.
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Ty);
if (TLI->isOperationLegalOrPromote(ISD, LT.second)) {
// The operation is legal. Assume it costs 1.
// If the type is split to multiple registers, assume that thre is some
// overhead to this.
// TODO: Once we have extract/insert subvector cost we need to use them.
if (LT.first > 1)
return LT.first * 2;
return LT.first * 1;
}
if (!TLI->isOperationExpand(ISD, LT.second)) {
// If the operation is custom lowered then assume
// thare the code is twice as expensive.
return LT.first * 2;
}
// Else, assume that we need to scalarize this op.
if (Ty->isVectorTy()) {
unsigned Num = Ty->getVectorNumElements();
unsigned Cost = TopTTI->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 1;
}
unsigned BasicTTI::getShuffleCost(ShuffleKind Kind, Type *Tp, int Index,
Type *SubTp) const {
return 1;
}
unsigned BasicTTI::getCastInstrCost(unsigned Opcode, Type *Dst,
Type *Src) const {
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
std::pair<unsigned, MVT> SrcLT = TLI->getTypeLegalizationCost(Src);
std::pair<unsigned, MVT> DstLT = TLI->getTypeLegalizationCost(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 the cast is marked as legal (or promote) then assume low cost.
if (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.
unsigned Num = Dst->getVectorNumElements();
unsigned Cost = TopTTI->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 BasicTTI::getCFInstrCost(unsigned Opcode) const {
// Branches are assumed to be predicted.
return 0;
}
unsigned BasicTTI::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
Type *CondTy) const {
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(ValTy);
if (!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 = TopTTI->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 BasicTTI::getVectorInstrCost(unsigned Opcode, Type *Val,
unsigned Index) const {
return 1;
}
unsigned BasicTTI::getMemoryOpCost(unsigned Opcode, Type *Src,
unsigned Alignment,
unsigned AddressSpace) const {
assert(!Src->isVoidTy() && "Invalid type");
std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Src);
// Assume that all loads of legal types cost 1.
return LT.first;
}
unsigned BasicTTI::getIntrinsicInstrCost(Intrinsic::ID, Type *RetTy,
ArrayRef<Type *> Tys) const {
// assume that we need to scalarize this intrinsic.
unsigned ScalarizationCost = 0;
unsigned ScalarCalls = 1;
if (RetTy->isVectorTy()) {
ScalarizationCost = getScalarizationOverhead(RetTy, true, false);
ScalarCalls = std::max(ScalarCalls, RetTy->getVectorNumElements());
}
for (unsigned i = 0, ie = Tys.size(); i != ie; ++i) {
if (Tys[i]->isVectorTy()) {
ScalarizationCost += getScalarizationOverhead(Tys[i], false, true);
ScalarCalls = std::max(ScalarCalls, RetTy->getVectorNumElements());
}
}
return ScalarCalls + ScalarizationCost;
}
unsigned BasicTTI::getNumberOfParts(Type *Tp) const {
std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Tp);
return LT.first;
}
unsigned BasicTTI::getAddressComputationCost(Type *Ty) const {
return 0;
}