// variables as volatile if they are live across a setjmp call, and they
// probably won't do this in callers.
if (const Function *F = CS.getCalledFunction()) {
+ // If a function is both internal and has a single use, then it is
+ // extremely likely to get inlined in the future (it was probably
+ // exposed by an interleaved devirtualization pass).
+ if (F->hasInternalLinkage() && F->hasOneUse())
+ ++NumInlineCandidates;
+
if (F->isDeclaration() &&
(F->getName() == "setjmp" || F->getName() == "_setjmp"))
callsSetJmp = true;
NumBBInsts[BB] = NumInsts - NumInstsBeforeThisBB;
}
+// CountBonusForConstant - Figure out an approximation for how much per-call
+// performance boost we can expect if the specified value is constant.
+unsigned CodeMetrics::CountBonusForConstant(Value *V) {
+ unsigned Bonus = 0;
+ for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){
+ User *U = *UI;
+ if (CallInst *CI = dyn_cast<CallInst>(U)) {
+ // Turning an indirect call into a direct call is a BIG win
+ if (CI->getCalledValue() == V)
+ Bonus += InlineConstants::IndirectCallBonus;
+ }
+ else if (InvokeInst *II = dyn_cast<InvokeInst>(U)) {
+ // Turning an indirect call into a direct call is a BIG win
+ if (II->getCalledValue() == V)
+ Bonus += InlineConstants::IndirectCallBonus;
+ }
+ // FIXME: Eliminating conditional branches and switches should
+ // also yield a per-call performance boost.
+ else {
+ // Figure out the bonuses that wll accrue due to simple constant
+ // propagation.
+ Instruction &Inst = cast<Instruction>(*U);
+
+ // We can't constant propagate instructions which have effects or
+ // read memory.
+ //
+ // FIXME: It would be nice to capture the fact that a load from a
+ // pointer-to-constant-global is actually a *really* good thing to zap.
+ // Unfortunately, we don't know the pointer that may get propagated here,
+ // so we can't make this decision.
+ 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)
+ Bonus += CountBonusForConstant(&Inst);
+ }
+ }
+ return Bonus;
+}
+
+
// CountCodeReductionForConstant - Figure out an approximation for how many
// instructions will be constant folded if the specified value is constant.
//
Instrs += NumBBInsts[TI.getSuccessor(I)];
// We don't know which blocks will be eliminated, so use the average size.
Reduction += InlineConstants::InstrCost*Instrs*(NumSucc-1)/NumSucc;
- } else if (CallInst *CI = dyn_cast<CallInst>(U)) {
- // Turning an indirect call into a direct call is a BIG win
- if (CI->getCalledValue() == V)
- Reduction += InlineConstants::IndirectCallBonus;
- } else if (InvokeInst *II = dyn_cast<InvokeInst>(U)) {
- // Turning an indirect call into a direct call is a BIG win
- if (II->getCalledValue() == V)
- Reduction += InlineConstants::IndirectCallBonus;
} else {
// Figure out if this instruction will be removed due to simple constant
// propagation.
ArgumentWeights.reserve(F->arg_size());
for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
ArgumentWeights.push_back(ArgInfo(Metrics.CountCodeReductionForConstant(I),
- Metrics.CountCodeReductionForAlloca(I)));
+ Metrics.CountCodeReductionForAlloca(I),
+ Metrics.CountBonusForConstant(I)));
}
/// NeverInline - returns true if the function should never be inlined into
Metrics.containsIndirectBr);
}
+// getSpecializationBonus - The heuristic used to determine the per-call
+// performance boost for using a specialization of Callee with argument
+// specializedArgNo replaced by a constant.
+int InlineCostAnalyzer::getSpecializationBonus(Function *Callee,
+ SmallVectorImpl<unsigned> &SpecializedArgNos)
+{
+ if (Callee->mayBeOverridden())
+ return 0;
+
+ int Bonus = 0;
+ // If this function uses the coldcc calling convention, prefer not to
+ // specialize it.
+ if (Callee->getCallingConv() == CallingConv::Cold)
+ Bonus -= InlineConstants::ColdccPenalty;
+
+ // Get information about the callee.
+ FunctionInfo *CalleeFI = &CachedFunctionInfo[Callee];
+
+ // If we haven't calculated this information yet, do so now.
+ if (CalleeFI->Metrics.NumBlocks == 0)
+ CalleeFI->analyzeFunction(Callee);
+
+
+ for (unsigned i = 0, s = SpecializedArgNos.size();
+ i < s; ++i )
+ {
+ Bonus += CalleeFI->ArgumentWeights[SpecializedArgNos[i]].ConstantBonus;
+ }
+ // Calls usually take a long time, so they make the specialization gain
+ // smaller.
+ Bonus -= CalleeFI->Metrics.NumCalls * InlineConstants::CallPenalty;
+
+ return Bonus;
+}
+
+
// getInlineCost - The heuristic used to determine if we should inline the
// function call or not.
//
// away with this information.
} else if (isa<Constant>(I)) {
if (ArgNo < CalleeFI->ArgumentWeights.size())
- InlineCost -= CalleeFI->ArgumentWeights[ArgNo].ConstantWeight;
+ InlineCost -= (CalleeFI->ArgumentWeights[ArgNo].ConstantWeight +
+ CalleeFI->ArgumentWeights[ArgNo].ConstantBonus);
}
}
return llvm::InlineCost::get(InlineCost);
}
+// getSpecializationCost - The heuristic used to determine the code-size
+// impact of creating a specialized version of Callee with argument
+// SpecializedArgNo replaced by a constant.
+InlineCost InlineCostAnalyzer::getSpecializationCost(Function *Callee,
+ SmallVectorImpl<unsigned> &SpecializedArgNos)
+{
+ // Don't specialize functions which can be redefined at link-time to mean
+ // something else.
+ if (Callee->mayBeOverridden())
+ return llvm::InlineCost::getNever();
+
+ // Get information about the callee.
+ FunctionInfo *CalleeFI = &CachedFunctionInfo[Callee];
+
+ // If we haven't calculated this information yet, do so now.
+ if (CalleeFI->Metrics.NumBlocks == 0)
+ CalleeFI->analyzeFunction(Callee);
+
+ int Cost = 0;
+
+ // Look at the orginal size of the callee. Each instruction counts as 5.
+ Cost += CalleeFI->Metrics.NumInsts * InlineConstants::InstrCost;
+
+ // Offset that with the amount of code that can be constant-folded
+ // away with the given arguments replaced by constants.
+ for (SmallVectorImpl<unsigned>::iterator an = SpecializedArgNos.begin(),
+ ae = SpecializedArgNos.end(); an != ae; ++an)
+ {
+ Cost -= CalleeFI->ArgumentWeights[*an].ConstantWeight;
+ }
+
+ return llvm::InlineCost::get(Cost);
+}
+
// getInlineFudgeFactor - Return a > 1.0 factor if the inliner should use a
// higher threshold to determine if the function call should be inlined.
float InlineCostAnalyzer::getInlineFudgeFactor(CallSite CS) {
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