#include "llvm/Analysis/InlineCost.h"
#include "llvm/Support/CallSite.h"
#include "llvm/CallingConv.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/ADT/SmallPtrSet.h"
using namespace llvm;
unsigned InlineCostAnalyzer::FunctionInfo::
CountCodeReductionForConstant(Value *V) {
unsigned Reduction = 0;
bool indirectCallBonus = false;
for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E; ++UI)
if (isa<BranchInst>(*UI) || isa<SwitchInst>(*UI)) {
const TerminatorInst &TI = cast<TerminatorInst>(**UI);
const unsigned NumSucc = TI.getNumSuccessors();
unsigned Instrs = 0;
for (unsigned I = 0; I != NumSucc; ++I)
Instrs += Metrics.NumBBInsts[TI.getSuccessor(I)];
Reduction += InlineConstants::InstrCost*Instrs*(NumSucc-1)/NumSucc;
} else if (CallInst *CI = dyn_cast<CallInst>(*UI)) {
if (CI->getCalledValue() == V)
indirectCallBonus = true;
} else if (InvokeInst *II = dyn_cast<InvokeInst>(*UI)) {
if (II->getCalledValue() == V)
indirectCallBonus = true;
} else {
Instruction &Inst = cast<Instruction>(**UI);
if (Inst.mayReadFromMemory() || Inst.mayHaveSideEffects() ||
isa<AllocaInst>(Inst))
continue;
bool AllOperandsConstant = true;
for (unsigned i = 0, e = Inst.getNumOperands(); i != e; ++i)
if (!isa<Constant>(Inst.getOperand(i)) && Inst.getOperand(i) != V) {
AllOperandsConstant = false;
break;
}
if (AllOperandsConstant) {
Reduction += InlineConstants::InstrCost;
Reduction += CountCodeReductionForConstant(&Inst);
}
}
if (indirectCallBonus) Reduction += InlineConstants::IndirectCallBonus;
return Reduction;
}
unsigned InlineCostAnalyzer::FunctionInfo::
CountCodeReductionForAlloca(Value *V) {
if (!V->getType()->isPointerTy()) return 0; unsigned Reduction = 0;
for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){
Instruction *I = cast<Instruction>(*UI);
if (isa<LoadInst>(I) || isa<StoreInst>(I))
Reduction += InlineConstants::InstrCost;
else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) {
if (GEP->hasAllConstantIndices())
Reduction += CountCodeReductionForAlloca(GEP);
} else if (BitCastInst *BCI = dyn_cast<BitCastInst>(I)) {
Reduction += CountCodeReductionForAlloca(BCI);
} else {
return 0;
}
}
return Reduction;
}
static bool callIsSmall(const Function *F) {
if (!F) return false;
if (F->hasLocalLinkage()) return false;
if (!F->hasName()) return false;
StringRef Name = F->getName();
if (Name == "copysign" || Name == "copysignf" || Name == "copysignl" ||
Name == "fabs" || Name == "fabsf" || Name == "fabsl" ||
Name == "sin" || Name == "sinf" || Name == "sinl" ||
Name == "cos" || Name == "cosf" || Name == "cosl" ||
Name == "sqrt" || Name == "sqrtf" || Name == "sqrtl" )
return true;
if (Name == "pow" || Name == "powf" || Name == "powl" ||
Name == "exp2" || Name == "exp2l" || Name == "exp2f" ||
Name == "floor" || Name == "floorf" || Name == "ceil" ||
Name == "round" || Name == "ffs" || Name == "ffsl" ||
Name == "abs" || Name == "labs" || Name == "llabs")
return true;
return false;
}
void CodeMetrics::analyzeBasicBlock(const BasicBlock *BB) {
++NumBlocks;
unsigned NumInstsBeforeThisBB = NumInsts;
for (BasicBlock::const_iterator II = BB->begin(), E = BB->end();
II != E; ++II) {
if (isa<PHINode>(II)) continue;
if (isa<CallInst>(II) || isa<InvokeInst>(II)) {
if (isa<DbgInfoIntrinsic>(II))
continue;
CallSite CS = CallSite::get(const_cast<Instruction*>(&*II));
if (Function *F = CS.getCalledFunction())
if (F->isDeclaration() &&
(F->getName() == "setjmp" || F->getName() == "_setjmp"))
NeverInline = true;
if (!isa<IntrinsicInst>(II) && !callIsSmall(CS.getCalledFunction())) {
NumInsts += CS.arg_size();
++NumCalls;
}
}
if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
if (!AI->isStaticAlloca())
this->usesDynamicAlloca = true;
}
if (isa<ExtractElementInst>(II) || II->getType()->isVectorTy())
++NumVectorInsts;
if (const CastInst *CI = dyn_cast<CastInst>(II)) {
if (CI->isLosslessCast() || isa<IntToPtrInst>(CI) ||
isa<PtrToIntInst>(CI))
continue;
if (isa<CmpInst>(CI->getOperand(0)))
continue;
} else if (const GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(II)){
if (GEPI->hasAllConstantIndices())
continue;
}
++NumInsts;
}
if (isa<ReturnInst>(BB->getTerminator()))
++NumRets;
if (isa<IndirectBrInst>(BB->getTerminator()))
NeverInline = true;
NumBBInsts[BB] = NumInsts - NumInstsBeforeThisBB;
}
void CodeMetrics::analyzeFunction(Function *F) {
for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
analyzeBasicBlock(&*BB);
}
void InlineCostAnalyzer::FunctionInfo::analyzeFunction(Function *F) {
Metrics.analyzeFunction(F);
if (Metrics.NumRets==1)
--Metrics.NumInsts;
if (Metrics.NeverInline)
return;
ArgumentWeights.reserve(F->arg_size());
for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
ArgumentWeights.push_back(ArgInfo(CountCodeReductionForConstant(I),
CountCodeReductionForAlloca(I)));
}
InlineCost InlineCostAnalyzer::getInlineCost(CallSite CS,
SmallPtrSet<const Function*, 16> &NeverInline) {
Instruction *TheCall = CS.getInstruction();
Function *Callee = CS.getCalledFunction();
Function *Caller = TheCall->getParent()->getParent();
if (Callee->mayBeOverridden() ||
Callee->hasFnAttr(Attribute::NoInline) || NeverInline.count(Callee))
return llvm::InlineCost::getNever();
int InlineCost = 0;
if (Callee->hasLocalLinkage() && Callee->hasOneUse())
InlineCost += InlineConstants::LastCallToStaticBonus;
if (Callee->getCallingConv() == CallingConv::Cold)
InlineCost += InlineConstants::ColdccPenalty;
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) {
if (isa<UnreachableInst>(II->getNormalDest()->begin()))
InlineCost += InlineConstants::NoreturnPenalty;
} else if (isa<UnreachableInst>(++BasicBlock::iterator(TheCall)))
InlineCost += InlineConstants::NoreturnPenalty;
FunctionInfo *CalleeFI = &CachedFunctionInfo[Callee];
if (CalleeFI->Metrics.NumBlocks == 0)
CalleeFI->analyzeFunction(Callee);
if (CalleeFI->Metrics.NeverInline)
return InlineCost::getNever();
if (!Callee->isDeclaration() && Callee->hasFnAttr(Attribute::AlwaysInline))
return InlineCost::getAlways();
if (CalleeFI->Metrics.usesDynamicAlloca) {
FunctionInfo &CallerFI = CachedFunctionInfo[Caller];
if (CallerFI.Metrics.NumBlocks == 0) {
CallerFI.analyzeFunction(Caller);
CalleeFI = &CachedFunctionInfo[Callee];
}
if (!CallerFI.Metrics.usesDynamicAlloca)
return InlineCost::getNever();
}
unsigned ArgNo = 0;
for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
I != E; ++I, ++ArgNo) {
InlineCost -= InlineConstants::InstrCost;
if (isa<AllocaInst>(I)) {
if (ArgNo < CalleeFI->ArgumentWeights.size())
InlineCost -= CalleeFI->ArgumentWeights[ArgNo].AllocaWeight;
} else if (isa<Constant>(I)) {
if (ArgNo < CalleeFI->ArgumentWeights.size())
InlineCost -= CalleeFI->ArgumentWeights[ArgNo].ConstantWeight;
}
}
InlineCost += CalleeFI->Metrics.NumCalls * InlineConstants::CallPenalty;
InlineCost += CalleeFI->Metrics.NumInsts*InlineConstants::InstrCost;
return llvm::InlineCost::get(InlineCost);
}
float InlineCostAnalyzer::getInlineFudgeFactor(CallSite CS) {
Function *Callee = CS.getCalledFunction();
FunctionInfo &CalleeFI = CachedFunctionInfo[Callee];
if (CalleeFI.Metrics.NumBlocks == 0)
CalleeFI.analyzeFunction(Callee);
float Factor = 1.0f;
if (CalleeFI.Metrics.NumBlocks == 1)
Factor += 0.5f;
if (CalleeFI.Metrics.NumVectorInsts > CalleeFI.Metrics.NumInsts/2)
Factor += 2.0f;
else if (CalleeFI.Metrics.NumVectorInsts > CalleeFI.Metrics.NumInsts/10)
Factor += 1.5f;
return Factor;
}
void
InlineCostAnalyzer::growCachedCostInfo(Function *Caller, Function *Callee) {
CodeMetrics &CallerMetrics = CachedFunctionInfo[Caller].Metrics;
if (CallerMetrics.NumBlocks < 10 || CallerMetrics.NumInsts < 1000) {
resetCachedCostInfo(Caller);
return;
}
if (CallerMetrics.NumCalls > 0)
--CallerMetrics.NumCalls;
if (Callee == 0) return;
CodeMetrics &CalleeMetrics = CachedFunctionInfo[Callee].Metrics;
if (CalleeMetrics.NumBlocks == 0) {
resetCachedCostInfo(Caller);
return;
}
CallerMetrics.NeverInline |= CalleeMetrics.NeverInline;
CallerMetrics.usesDynamicAlloca |= CalleeMetrics.usesDynamicAlloca;
CallerMetrics.NumInsts += CalleeMetrics.NumInsts;
CallerMetrics.NumBlocks += CalleeMetrics.NumBlocks;
CallerMetrics.NumCalls += CalleeMetrics.NumCalls;
CallerMetrics.NumVectorInsts += CalleeMetrics.NumVectorInsts;
CallerMetrics.NumRets += CalleeMetrics.NumRets;
if (CallerMetrics.NumInsts >= Callee->arg_size())
CallerMetrics.NumInsts -= Callee->arg_size();
else
CallerMetrics.NumInsts = 0;
}