mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-26 21:32:10 +00:00
4da253756d
definition below all the header #include lines, lib/Analysis/... edition. This one has a bit extra as there were *other* #define's before #include lines in addition to DEBUG_TYPE. I've sunk all of them as a block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206843 91177308-0d34-0410-b5e6-96231b3b80d8
507 lines
17 KiB
C++
507 lines
17 KiB
C++
//===- CostModel.cpp ------ Cost Model Analysis ---------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines the cost model analysis. It provides a very basic cost
|
|
// estimation for LLVM-IR. This analysis uses the services of the codegen
|
|
// to approximate the cost of any IR instruction when lowered to machine
|
|
// instructions. The cost results are unit-less and the cost number represents
|
|
// the throughput of the machine assuming that all loads hit the cache, all
|
|
// branches are predicted, etc. The cost numbers can be added in order to
|
|
// compare two or more transformation alternatives.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/ADT/STLExtras.h"
|
|
#include "llvm/Analysis/Passes.h"
|
|
#include "llvm/Analysis/TargetTransformInfo.h"
|
|
#include "llvm/IR/Function.h"
|
|
#include "llvm/IR/Instructions.h"
|
|
#include "llvm/IR/IntrinsicInst.h"
|
|
#include "llvm/IR/Value.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Support/CommandLine.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
using namespace llvm;
|
|
|
|
#define CM_NAME "cost-model"
|
|
#define DEBUG_TYPE CM_NAME
|
|
|
|
static cl::opt<bool> EnableReduxCost("costmodel-reduxcost", cl::init(false),
|
|
cl::Hidden,
|
|
cl::desc("Recognize reduction patterns."));
|
|
|
|
namespace {
|
|
class CostModelAnalysis : public FunctionPass {
|
|
|
|
public:
|
|
static char ID; // Class identification, replacement for typeinfo
|
|
CostModelAnalysis() : FunctionPass(ID), F(nullptr), TTI(nullptr) {
|
|
initializeCostModelAnalysisPass(
|
|
*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
/// Returns the expected cost of the instruction.
|
|
/// Returns -1 if the cost is unknown.
|
|
/// Note, this method does not cache the cost calculation and it
|
|
/// can be expensive in some cases.
|
|
unsigned getInstructionCost(const Instruction *I) const;
|
|
|
|
private:
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override;
|
|
bool runOnFunction(Function &F) override;
|
|
void print(raw_ostream &OS, const Module*) const override;
|
|
|
|
/// The function that we analyze.
|
|
Function *F;
|
|
/// Target information.
|
|
const TargetTransformInfo *TTI;
|
|
};
|
|
} // End of anonymous namespace
|
|
|
|
// Register this pass.
|
|
char CostModelAnalysis::ID = 0;
|
|
static const char cm_name[] = "Cost Model Analysis";
|
|
INITIALIZE_PASS_BEGIN(CostModelAnalysis, CM_NAME, cm_name, false, true)
|
|
INITIALIZE_PASS_END (CostModelAnalysis, CM_NAME, cm_name, false, true)
|
|
|
|
FunctionPass *llvm::createCostModelAnalysisPass() {
|
|
return new CostModelAnalysis();
|
|
}
|
|
|
|
void
|
|
CostModelAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
|
|
AU.setPreservesAll();
|
|
}
|
|
|
|
bool
|
|
CostModelAnalysis::runOnFunction(Function &F) {
|
|
this->F = &F;
|
|
TTI = getAnalysisIfAvailable<TargetTransformInfo>();
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool isReverseVectorMask(SmallVectorImpl<int> &Mask) {
|
|
for (unsigned i = 0, MaskSize = Mask.size(); i < MaskSize; ++i)
|
|
if (Mask[i] > 0 && Mask[i] != (int)(MaskSize - 1 - i))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static TargetTransformInfo::OperandValueKind getOperandInfo(Value *V) {
|
|
TargetTransformInfo::OperandValueKind OpInfo =
|
|
TargetTransformInfo::OK_AnyValue;
|
|
|
|
// Check for a splat of a constant or for a non uniform vector of constants.
|
|
if (isa<ConstantVector>(V) || isa<ConstantDataVector>(V)) {
|
|
OpInfo = TargetTransformInfo::OK_NonUniformConstantValue;
|
|
if (cast<Constant>(V)->getSplatValue() != nullptr)
|
|
OpInfo = TargetTransformInfo::OK_UniformConstantValue;
|
|
}
|
|
|
|
return OpInfo;
|
|
}
|
|
|
|
static bool matchPairwiseShuffleMask(ShuffleVectorInst *SI, bool IsLeft,
|
|
unsigned Level) {
|
|
// We don't need a shuffle if we just want to have element 0 in position 0 of
|
|
// the vector.
|
|
if (!SI && Level == 0 && IsLeft)
|
|
return true;
|
|
else if (!SI)
|
|
return false;
|
|
|
|
SmallVector<int, 32> Mask(SI->getType()->getVectorNumElements(), -1);
|
|
|
|
// Build a mask of 0, 2, ... (left) or 1, 3, ... (right) depending on whether
|
|
// we look at the left or right side.
|
|
for (unsigned i = 0, e = (1 << Level), val = !IsLeft; i != e; ++i, val += 2)
|
|
Mask[i] = val;
|
|
|
|
SmallVector<int, 16> ActualMask = SI->getShuffleMask();
|
|
if (Mask != ActualMask)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool matchPairwiseReductionAtLevel(const BinaryOperator *BinOp,
|
|
unsigned Level, unsigned NumLevels) {
|
|
// Match one level of pairwise operations.
|
|
// %rdx.shuf.0.0 = shufflevector <4 x float> %rdx, <4 x float> undef,
|
|
// <4 x i32> <i32 0, i32 2 , i32 undef, i32 undef>
|
|
// %rdx.shuf.0.1 = shufflevector <4 x float> %rdx, <4 x float> undef,
|
|
// <4 x i32> <i32 1, i32 3, i32 undef, i32 undef>
|
|
// %bin.rdx.0 = fadd <4 x float> %rdx.shuf.0.0, %rdx.shuf.0.1
|
|
if (BinOp == nullptr)
|
|
return false;
|
|
|
|
assert(BinOp->getType()->isVectorTy() && "Expecting a vector type");
|
|
|
|
unsigned Opcode = BinOp->getOpcode();
|
|
Value *L = BinOp->getOperand(0);
|
|
Value *R = BinOp->getOperand(1);
|
|
|
|
ShuffleVectorInst *LS = dyn_cast<ShuffleVectorInst>(L);
|
|
if (!LS && Level)
|
|
return false;
|
|
ShuffleVectorInst *RS = dyn_cast<ShuffleVectorInst>(R);
|
|
if (!RS && Level)
|
|
return false;
|
|
|
|
// On level 0 we can omit one shufflevector instruction.
|
|
if (!Level && !RS && !LS)
|
|
return false;
|
|
|
|
// Shuffle inputs must match.
|
|
Value *NextLevelOpL = LS ? LS->getOperand(0) : nullptr;
|
|
Value *NextLevelOpR = RS ? RS->getOperand(0) : nullptr;
|
|
Value *NextLevelOp = nullptr;
|
|
if (NextLevelOpR && NextLevelOpL) {
|
|
// If we have two shuffles their operands must match.
|
|
if (NextLevelOpL != NextLevelOpR)
|
|
return false;
|
|
|
|
NextLevelOp = NextLevelOpL;
|
|
} else if (Level == 0 && (NextLevelOpR || NextLevelOpL)) {
|
|
// On the first level we can omit the shufflevector <0, undef,...>. So the
|
|
// input to the other shufflevector <1, undef> must match with one of the
|
|
// inputs to the current binary operation.
|
|
// Example:
|
|
// %NextLevelOpL = shufflevector %R, <1, undef ...>
|
|
// %BinOp = fadd %NextLevelOpL, %R
|
|
if (NextLevelOpL && NextLevelOpL != R)
|
|
return false;
|
|
else if (NextLevelOpR && NextLevelOpR != L)
|
|
return false;
|
|
|
|
NextLevelOp = NextLevelOpL ? R : L;
|
|
} else
|
|
return false;
|
|
|
|
// Check that the next levels binary operation exists and matches with the
|
|
// current one.
|
|
BinaryOperator *NextLevelBinOp = nullptr;
|
|
if (Level + 1 != NumLevels) {
|
|
if (!(NextLevelBinOp = dyn_cast<BinaryOperator>(NextLevelOp)))
|
|
return false;
|
|
else if (NextLevelBinOp->getOpcode() != Opcode)
|
|
return false;
|
|
}
|
|
|
|
// Shuffle mask for pairwise operation must match.
|
|
if (matchPairwiseShuffleMask(LS, true, Level)) {
|
|
if (!matchPairwiseShuffleMask(RS, false, Level))
|
|
return false;
|
|
} else if (matchPairwiseShuffleMask(RS, true, Level)) {
|
|
if (!matchPairwiseShuffleMask(LS, false, Level))
|
|
return false;
|
|
} else
|
|
return false;
|
|
|
|
if (++Level == NumLevels)
|
|
return true;
|
|
|
|
// Match next level.
|
|
return matchPairwiseReductionAtLevel(NextLevelBinOp, Level, NumLevels);
|
|
}
|
|
|
|
static bool matchPairwiseReduction(const ExtractElementInst *ReduxRoot,
|
|
unsigned &Opcode, Type *&Ty) {
|
|
if (!EnableReduxCost)
|
|
return false;
|
|
|
|
// Need to extract the first element.
|
|
ConstantInt *CI = dyn_cast<ConstantInt>(ReduxRoot->getOperand(1));
|
|
unsigned Idx = ~0u;
|
|
if (CI)
|
|
Idx = CI->getZExtValue();
|
|
if (Idx != 0)
|
|
return false;
|
|
|
|
BinaryOperator *RdxStart = dyn_cast<BinaryOperator>(ReduxRoot->getOperand(0));
|
|
if (!RdxStart)
|
|
return false;
|
|
|
|
Type *VecTy = ReduxRoot->getOperand(0)->getType();
|
|
unsigned NumVecElems = VecTy->getVectorNumElements();
|
|
if (!isPowerOf2_32(NumVecElems))
|
|
return false;
|
|
|
|
// We look for a sequence of shuffle,shuffle,add triples like the following
|
|
// that builds a pairwise reduction tree.
|
|
//
|
|
// (X0, X1, X2, X3)
|
|
// (X0 + X1, X2 + X3, undef, undef)
|
|
// ((X0 + X1) + (X2 + X3), undef, undef, undef)
|
|
//
|
|
// %rdx.shuf.0.0 = shufflevector <4 x float> %rdx, <4 x float> undef,
|
|
// <4 x i32> <i32 0, i32 2 , i32 undef, i32 undef>
|
|
// %rdx.shuf.0.1 = shufflevector <4 x float> %rdx, <4 x float> undef,
|
|
// <4 x i32> <i32 1, i32 3, i32 undef, i32 undef>
|
|
// %bin.rdx.0 = fadd <4 x float> %rdx.shuf.0.0, %rdx.shuf.0.1
|
|
// %rdx.shuf.1.0 = shufflevector <4 x float> %bin.rdx.0, <4 x float> undef,
|
|
// <4 x i32> <i32 0, i32 undef, i32 undef, i32 undef>
|
|
// %rdx.shuf.1.1 = shufflevector <4 x float> %bin.rdx.0, <4 x float> undef,
|
|
// <4 x i32> <i32 1, i32 undef, i32 undef, i32 undef>
|
|
// %bin.rdx8 = fadd <4 x float> %rdx.shuf.1.0, %rdx.shuf.1.1
|
|
// %r = extractelement <4 x float> %bin.rdx8, i32 0
|
|
if (!matchPairwiseReductionAtLevel(RdxStart, 0, Log2_32(NumVecElems)))
|
|
return false;
|
|
|
|
Opcode = RdxStart->getOpcode();
|
|
Ty = VecTy;
|
|
|
|
return true;
|
|
}
|
|
|
|
static std::pair<Value *, ShuffleVectorInst *>
|
|
getShuffleAndOtherOprd(BinaryOperator *B) {
|
|
|
|
Value *L = B->getOperand(0);
|
|
Value *R = B->getOperand(1);
|
|
ShuffleVectorInst *S = nullptr;
|
|
|
|
if ((S = dyn_cast<ShuffleVectorInst>(L)))
|
|
return std::make_pair(R, S);
|
|
|
|
S = dyn_cast<ShuffleVectorInst>(R);
|
|
return std::make_pair(L, S);
|
|
}
|
|
|
|
static bool matchVectorSplittingReduction(const ExtractElementInst *ReduxRoot,
|
|
unsigned &Opcode, Type *&Ty) {
|
|
if (!EnableReduxCost)
|
|
return false;
|
|
|
|
// Need to extract the first element.
|
|
ConstantInt *CI = dyn_cast<ConstantInt>(ReduxRoot->getOperand(1));
|
|
unsigned Idx = ~0u;
|
|
if (CI)
|
|
Idx = CI->getZExtValue();
|
|
if (Idx != 0)
|
|
return false;
|
|
|
|
BinaryOperator *RdxStart = dyn_cast<BinaryOperator>(ReduxRoot->getOperand(0));
|
|
if (!RdxStart)
|
|
return false;
|
|
unsigned RdxOpcode = RdxStart->getOpcode();
|
|
|
|
Type *VecTy = ReduxRoot->getOperand(0)->getType();
|
|
unsigned NumVecElems = VecTy->getVectorNumElements();
|
|
if (!isPowerOf2_32(NumVecElems))
|
|
return false;
|
|
|
|
// We look for a sequence of shuffles and adds like the following matching one
|
|
// fadd, shuffle vector pair at a time.
|
|
//
|
|
// %rdx.shuf = shufflevector <4 x float> %rdx, <4 x float> undef,
|
|
// <4 x i32> <i32 2, i32 3, i32 undef, i32 undef>
|
|
// %bin.rdx = fadd <4 x float> %rdx, %rdx.shuf
|
|
// %rdx.shuf7 = shufflevector <4 x float> %bin.rdx, <4 x float> undef,
|
|
// <4 x i32> <i32 1, i32 undef, i32 undef, i32 undef>
|
|
// %bin.rdx8 = fadd <4 x float> %bin.rdx, %rdx.shuf7
|
|
// %r = extractelement <4 x float> %bin.rdx8, i32 0
|
|
|
|
unsigned MaskStart = 1;
|
|
Value *RdxOp = RdxStart;
|
|
SmallVector<int, 32> ShuffleMask(NumVecElems, 0);
|
|
unsigned NumVecElemsRemain = NumVecElems;
|
|
while (NumVecElemsRemain - 1) {
|
|
// Check for the right reduction operation.
|
|
BinaryOperator *BinOp;
|
|
if (!(BinOp = dyn_cast<BinaryOperator>(RdxOp)))
|
|
return false;
|
|
if (BinOp->getOpcode() != RdxOpcode)
|
|
return false;
|
|
|
|
Value *NextRdxOp;
|
|
ShuffleVectorInst *Shuffle;
|
|
std::tie(NextRdxOp, Shuffle) = getShuffleAndOtherOprd(BinOp);
|
|
|
|
// Check the current reduction operation and the shuffle use the same value.
|
|
if (Shuffle == nullptr)
|
|
return false;
|
|
if (Shuffle->getOperand(0) != NextRdxOp)
|
|
return false;
|
|
|
|
// Check that shuffle masks matches.
|
|
for (unsigned j = 0; j != MaskStart; ++j)
|
|
ShuffleMask[j] = MaskStart + j;
|
|
// Fill the rest of the mask with -1 for undef.
|
|
std::fill(&ShuffleMask[MaskStart], ShuffleMask.end(), -1);
|
|
|
|
SmallVector<int, 16> Mask = Shuffle->getShuffleMask();
|
|
if (ShuffleMask != Mask)
|
|
return false;
|
|
|
|
RdxOp = NextRdxOp;
|
|
NumVecElemsRemain /= 2;
|
|
MaskStart *= 2;
|
|
}
|
|
|
|
Opcode = RdxOpcode;
|
|
Ty = VecTy;
|
|
return true;
|
|
}
|
|
|
|
unsigned CostModelAnalysis::getInstructionCost(const Instruction *I) const {
|
|
if (!TTI)
|
|
return -1;
|
|
|
|
switch (I->getOpcode()) {
|
|
case Instruction::GetElementPtr:{
|
|
Type *ValTy = I->getOperand(0)->getType()->getPointerElementType();
|
|
return TTI->getAddressComputationCost(ValTy);
|
|
}
|
|
|
|
case Instruction::Ret:
|
|
case Instruction::PHI:
|
|
case Instruction::Br: {
|
|
return TTI->getCFInstrCost(I->getOpcode());
|
|
}
|
|
case Instruction::Add:
|
|
case Instruction::FAdd:
|
|
case Instruction::Sub:
|
|
case Instruction::FSub:
|
|
case Instruction::Mul:
|
|
case Instruction::FMul:
|
|
case Instruction::UDiv:
|
|
case Instruction::SDiv:
|
|
case Instruction::FDiv:
|
|
case Instruction::URem:
|
|
case Instruction::SRem:
|
|
case Instruction::FRem:
|
|
case Instruction::Shl:
|
|
case Instruction::LShr:
|
|
case Instruction::AShr:
|
|
case Instruction::And:
|
|
case Instruction::Or:
|
|
case Instruction::Xor: {
|
|
TargetTransformInfo::OperandValueKind Op1VK =
|
|
getOperandInfo(I->getOperand(0));
|
|
TargetTransformInfo::OperandValueKind Op2VK =
|
|
getOperandInfo(I->getOperand(1));
|
|
return TTI->getArithmeticInstrCost(I->getOpcode(), I->getType(), Op1VK,
|
|
Op2VK);
|
|
}
|
|
case Instruction::Select: {
|
|
const SelectInst *SI = cast<SelectInst>(I);
|
|
Type *CondTy = SI->getCondition()->getType();
|
|
return TTI->getCmpSelInstrCost(I->getOpcode(), I->getType(), CondTy);
|
|
}
|
|
case Instruction::ICmp:
|
|
case Instruction::FCmp: {
|
|
Type *ValTy = I->getOperand(0)->getType();
|
|
return TTI->getCmpSelInstrCost(I->getOpcode(), ValTy);
|
|
}
|
|
case Instruction::Store: {
|
|
const StoreInst *SI = cast<StoreInst>(I);
|
|
Type *ValTy = SI->getValueOperand()->getType();
|
|
return TTI->getMemoryOpCost(I->getOpcode(), ValTy,
|
|
SI->getAlignment(),
|
|
SI->getPointerAddressSpace());
|
|
}
|
|
case Instruction::Load: {
|
|
const LoadInst *LI = cast<LoadInst>(I);
|
|
return TTI->getMemoryOpCost(I->getOpcode(), I->getType(),
|
|
LI->getAlignment(),
|
|
LI->getPointerAddressSpace());
|
|
}
|
|
case Instruction::ZExt:
|
|
case Instruction::SExt:
|
|
case Instruction::FPToUI:
|
|
case Instruction::FPToSI:
|
|
case Instruction::FPExt:
|
|
case Instruction::PtrToInt:
|
|
case Instruction::IntToPtr:
|
|
case Instruction::SIToFP:
|
|
case Instruction::UIToFP:
|
|
case Instruction::Trunc:
|
|
case Instruction::FPTrunc:
|
|
case Instruction::BitCast:
|
|
case Instruction::AddrSpaceCast: {
|
|
Type *SrcTy = I->getOperand(0)->getType();
|
|
return TTI->getCastInstrCost(I->getOpcode(), I->getType(), SrcTy);
|
|
}
|
|
case Instruction::ExtractElement: {
|
|
const ExtractElementInst * EEI = cast<ExtractElementInst>(I);
|
|
ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1));
|
|
unsigned Idx = -1;
|
|
if (CI)
|
|
Idx = CI->getZExtValue();
|
|
|
|
// Try to match a reduction sequence (series of shufflevector and vector
|
|
// adds followed by a extractelement).
|
|
unsigned ReduxOpCode;
|
|
Type *ReduxType;
|
|
|
|
if (matchVectorSplittingReduction(EEI, ReduxOpCode, ReduxType))
|
|
return TTI->getReductionCost(ReduxOpCode, ReduxType, false);
|
|
else if (matchPairwiseReduction(EEI, ReduxOpCode, ReduxType))
|
|
return TTI->getReductionCost(ReduxOpCode, ReduxType, true);
|
|
|
|
return TTI->getVectorInstrCost(I->getOpcode(),
|
|
EEI->getOperand(0)->getType(), Idx);
|
|
}
|
|
case Instruction::InsertElement: {
|
|
const InsertElementInst * IE = cast<InsertElementInst>(I);
|
|
ConstantInt *CI = dyn_cast<ConstantInt>(IE->getOperand(2));
|
|
unsigned Idx = -1;
|
|
if (CI)
|
|
Idx = CI->getZExtValue();
|
|
return TTI->getVectorInstrCost(I->getOpcode(),
|
|
IE->getType(), Idx);
|
|
}
|
|
case Instruction::ShuffleVector: {
|
|
const ShuffleVectorInst *Shuffle = cast<ShuffleVectorInst>(I);
|
|
Type *VecTypOp0 = Shuffle->getOperand(0)->getType();
|
|
unsigned NumVecElems = VecTypOp0->getVectorNumElements();
|
|
SmallVector<int, 16> Mask = Shuffle->getShuffleMask();
|
|
|
|
if (NumVecElems == Mask.size() && isReverseVectorMask(Mask))
|
|
return TTI->getShuffleCost(TargetTransformInfo::SK_Reverse, VecTypOp0, 0,
|
|
nullptr);
|
|
return -1;
|
|
}
|
|
case Instruction::Call:
|
|
if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
|
|
SmallVector<Type*, 4> Tys;
|
|
for (unsigned J = 0, JE = II->getNumArgOperands(); J != JE; ++J)
|
|
Tys.push_back(II->getArgOperand(J)->getType());
|
|
|
|
return TTI->getIntrinsicInstrCost(II->getIntrinsicID(), II->getType(),
|
|
Tys);
|
|
}
|
|
return -1;
|
|
default:
|
|
// We don't have any information on this instruction.
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
void CostModelAnalysis::print(raw_ostream &OS, const Module*) const {
|
|
if (!F)
|
|
return;
|
|
|
|
for (Function::iterator B = F->begin(), BE = F->end(); B != BE; ++B) {
|
|
for (BasicBlock::iterator it = B->begin(), e = B->end(); it != e; ++it) {
|
|
Instruction *Inst = it;
|
|
unsigned Cost = getInstructionCost(Inst);
|
|
if (Cost != (unsigned)-1)
|
|
OS << "Cost Model: Found an estimated cost of " << Cost;
|
|
else
|
|
OS << "Cost Model: Unknown cost";
|
|
|
|
OS << " for instruction: "<< *Inst << "\n";
|
|
}
|
|
}
|
|
}
|