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Diffstat (limited to 'contrib/llvm/lib/Transforms/IPO/Inliner.cpp')
| -rw-r--r-- | contrib/llvm/lib/Transforms/IPO/Inliner.cpp | 636 |
1 files changed, 636 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Transforms/IPO/Inliner.cpp b/contrib/llvm/lib/Transforms/IPO/Inliner.cpp new file mode 100644 index 000000000000..d75d6ca92b3c --- /dev/null +++ b/contrib/llvm/lib/Transforms/IPO/Inliner.cpp @@ -0,0 +1,636 @@ +//===- Inliner.cpp - Code common to all inliners --------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements the mechanics required to implement inlining without +// missing any calls and updating the call graph. The decisions of which calls +// are profitable to inline are implemented elsewhere. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "inline" +#include "llvm/Transforms/IPO/InlinerPass.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/Analysis/CallGraph.h" +#include "llvm/Analysis/InlineCost.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/Module.h" +#include "llvm/Support/CallSite.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetLibraryInfo.h" +#include "llvm/Transforms/Utils/Cloning.h" +#include "llvm/Transforms/Utils/Local.h" +using namespace llvm; + +STATISTIC(NumInlined, "Number of functions inlined"); +STATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined"); +STATISTIC(NumDeleted, "Number of functions deleted because all callers found"); +STATISTIC(NumMergedAllocas, "Number of allocas merged together"); + +// This weirdly named statistic tracks the number of times that, when attempting +// to inline a function A into B, we analyze the callers of B in order to see +// if those would be more profitable and blocked inline steps. +STATISTIC(NumCallerCallersAnalyzed, "Number of caller-callers analyzed"); + +static cl::opt<int> +InlineLimit("inline-threshold", cl::Hidden, cl::init(225), cl::ZeroOrMore, + cl::desc("Control the amount of inlining to perform (default = 225)")); + +static cl::opt<int> +HintThreshold("inlinehint-threshold", cl::Hidden, cl::init(325), + cl::desc("Threshold for inlining functions with inline hint")); + +// Threshold to use when optsize is specified (and there is no -inline-limit). +const int OptSizeThreshold = 75; + +Inliner::Inliner(char &ID) + : CallGraphSCCPass(ID), InlineThreshold(InlineLimit), InsertLifetime(true) {} + +Inliner::Inliner(char &ID, int Threshold, bool InsertLifetime) + : CallGraphSCCPass(ID), InlineThreshold(InlineLimit.getNumOccurrences() > 0 ? + InlineLimit : Threshold), + InsertLifetime(InsertLifetime) {} + +/// getAnalysisUsage - For this class, we declare that we require and preserve +/// the call graph. If the derived class implements this method, it should +/// always explicitly call the implementation here. +void Inliner::getAnalysisUsage(AnalysisUsage &AU) const { + CallGraphSCCPass::getAnalysisUsage(AU); +} + + +typedef DenseMap<ArrayType*, std::vector<AllocaInst*> > +InlinedArrayAllocasTy; + +/// \brief If the inlined function had a higher stack protection level than the +/// calling function, then bump up the caller's stack protection level. +static void AdjustCallerSSPLevel(Function *Caller, Function *Callee) { + // If upgrading the SSP attribute, clear out the old SSP Attributes first. + // Having multiple SSP attributes doesn't actually hurt, but it adds useless + // clutter to the IR. + AttrBuilder B; + B.addAttribute(Attribute::StackProtect) + .addAttribute(Attribute::StackProtectStrong); + AttributeSet OldSSPAttr = AttributeSet::get(Caller->getContext(), + AttributeSet::FunctionIndex, + B); + AttributeSet CallerAttr = Caller->getAttributes(), + CalleeAttr = Callee->getAttributes(); + + if (CalleeAttr.hasAttribute(AttributeSet::FunctionIndex, + Attribute::StackProtectReq)) { + Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr); + Caller->addFnAttr(Attribute::StackProtectReq); + } else if (CalleeAttr.hasAttribute(AttributeSet::FunctionIndex, + Attribute::StackProtectStrong) && + !CallerAttr.hasAttribute(AttributeSet::FunctionIndex, + Attribute::StackProtectReq)) { + Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr); + Caller->addFnAttr(Attribute::StackProtectStrong); + } else if (CalleeAttr.hasAttribute(AttributeSet::FunctionIndex, + Attribute::StackProtect) && + !CallerAttr.hasAttribute(AttributeSet::FunctionIndex, + Attribute::StackProtectReq) && + !CallerAttr.hasAttribute(AttributeSet::FunctionIndex, + Attribute::StackProtectStrong)) + Caller->addFnAttr(Attribute::StackProtect); +} + +/// InlineCallIfPossible - If it is possible to inline the specified call site, +/// do so and update the CallGraph for this operation. +/// +/// This function also does some basic book-keeping to update the IR. The +/// InlinedArrayAllocas map keeps track of any allocas that are already +/// available from other functions inlined into the caller. If we are able to +/// inline this call site we attempt to reuse already available allocas or add +/// any new allocas to the set if not possible. +static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, + InlinedArrayAllocasTy &InlinedArrayAllocas, + int InlineHistory, bool InsertLifetime, + const DataLayout *TD) { + Function *Callee = CS.getCalledFunction(); + Function *Caller = CS.getCaller(); + + // Try to inline the function. Get the list of static allocas that were + // inlined. + if (!InlineFunction(CS, IFI, InsertLifetime)) + return false; + + AdjustCallerSSPLevel(Caller, Callee); + + // Look at all of the allocas that we inlined through this call site. If we + // have already inlined other allocas through other calls into this function, + // then we know that they have disjoint lifetimes and that we can merge them. + // + // There are many heuristics possible for merging these allocas, and the + // different options have different tradeoffs. One thing that we *really* + // don't want to hurt is SRoA: once inlining happens, often allocas are no + // longer address taken and so they can be promoted. + // + // Our "solution" for that is to only merge allocas whose outermost type is an + // array type. These are usually not promoted because someone is using a + // variable index into them. These are also often the most important ones to + // merge. + // + // A better solution would be to have real memory lifetime markers in the IR + // and not have the inliner do any merging of allocas at all. This would + // allow the backend to do proper stack slot coloring of all allocas that + // *actually make it to the backend*, which is really what we want. + // + // Because we don't have this information, we do this simple and useful hack. + // + SmallPtrSet<AllocaInst*, 16> UsedAllocas; + + // When processing our SCC, check to see if CS was inlined from some other + // call site. For example, if we're processing "A" in this code: + // A() { B() } + // B() { x = alloca ... C() } + // C() { y = alloca ... } + // Assume that C was not inlined into B initially, and so we're processing A + // and decide to inline B into A. Doing this makes an alloca available for + // reuse and makes a callsite (C) available for inlining. When we process + // the C call site we don't want to do any alloca merging between X and Y + // because their scopes are not disjoint. We could make this smarter by + // keeping track of the inline history for each alloca in the + // InlinedArrayAllocas but this isn't likely to be a significant win. + if (InlineHistory != -1) // Only do merging for top-level call sites in SCC. + return true; + + // Loop over all the allocas we have so far and see if they can be merged with + // a previously inlined alloca. If not, remember that we had it. + for (unsigned AllocaNo = 0, e = IFI.StaticAllocas.size(); + AllocaNo != e; ++AllocaNo) { + AllocaInst *AI = IFI.StaticAllocas[AllocaNo]; + + // Don't bother trying to merge array allocations (they will usually be + // canonicalized to be an allocation *of* an array), or allocations whose + // type is not itself an array (because we're afraid of pessimizing SRoA). + ArrayType *ATy = dyn_cast<ArrayType>(AI->getAllocatedType()); + if (ATy == 0 || AI->isArrayAllocation()) + continue; + + // Get the list of all available allocas for this array type. + std::vector<AllocaInst*> &AllocasForType = InlinedArrayAllocas[ATy]; + + // Loop over the allocas in AllocasForType to see if we can reuse one. Note + // that we have to be careful not to reuse the same "available" alloca for + // multiple different allocas that we just inlined, we use the 'UsedAllocas' + // set to keep track of which "available" allocas are being used by this + // function. Also, AllocasForType can be empty of course! + bool MergedAwayAlloca = false; + for (unsigned i = 0, e = AllocasForType.size(); i != e; ++i) { + AllocaInst *AvailableAlloca = AllocasForType[i]; + + unsigned Align1 = AI->getAlignment(), + Align2 = AvailableAlloca->getAlignment(); + // If we don't have data layout information, and only one alloca is using + // the target default, then we can't safely merge them because we can't + // pick the greater alignment. + if (!TD && (!Align1 || !Align2) && Align1 != Align2) + continue; + + // The available alloca has to be in the right function, not in some other + // function in this SCC. + if (AvailableAlloca->getParent() != AI->getParent()) + continue; + + // If the inlined function already uses this alloca then we can't reuse + // it. + if (!UsedAllocas.insert(AvailableAlloca)) + continue; + + // Otherwise, we *can* reuse it, RAUW AI into AvailableAlloca and declare + // success! + DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI << "\n\t\tINTO: " + << *AvailableAlloca << '\n'); + + AI->replaceAllUsesWith(AvailableAlloca); + + if (Align1 != Align2) { + if (!Align1 || !Align2) { + assert(TD && "DataLayout required to compare default alignments"); + unsigned TypeAlign = TD->getABITypeAlignment(AI->getAllocatedType()); + + Align1 = Align1 ? Align1 : TypeAlign; + Align2 = Align2 ? Align2 : TypeAlign; + } + + if (Align1 > Align2) + AvailableAlloca->setAlignment(AI->getAlignment()); + } + + AI->eraseFromParent(); + MergedAwayAlloca = true; + ++NumMergedAllocas; + IFI.StaticAllocas[AllocaNo] = 0; + break; + } + + // If we already nuked the alloca, we're done with it. + if (MergedAwayAlloca) + continue; + + // If we were unable to merge away the alloca either because there are no + // allocas of the right type available or because we reused them all + // already, remember that this alloca came from an inlined function and mark + // it used so we don't reuse it for other allocas from this inline + // operation. + AllocasForType.push_back(AI); + UsedAllocas.insert(AI); + } + + return true; +} + +unsigned Inliner::getInlineThreshold(CallSite CS) const { + int thres = InlineThreshold; // -inline-threshold or else selected by + // overall opt level + + // If -inline-threshold is not given, listen to the optsize attribute when it + // would decrease the threshold. + Function *Caller = CS.getCaller(); + bool OptSize = Caller && !Caller->isDeclaration() && + Caller->getAttributes().hasAttribute(AttributeSet::FunctionIndex, + Attribute::OptimizeForSize); + if (!(InlineLimit.getNumOccurrences() > 0) && OptSize && + OptSizeThreshold < thres) + thres = OptSizeThreshold; + + // Listen to the inlinehint attribute when it would increase the threshold + // and the caller does not need to minimize its size. + Function *Callee = CS.getCalledFunction(); + bool InlineHint = Callee && !Callee->isDeclaration() && + Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex, + Attribute::InlineHint); + if (InlineHint && HintThreshold > thres + && !Caller->getAttributes().hasAttribute(AttributeSet::FunctionIndex, + Attribute::MinSize)) + thres = HintThreshold; + + return thres; +} + +/// shouldInline - Return true if the inliner should attempt to inline +/// at the given CallSite. +bool Inliner::shouldInline(CallSite CS) { + InlineCost IC = getInlineCost(CS); + + if (IC.isAlways()) { + DEBUG(dbgs() << " Inlining: cost=always" + << ", Call: " << *CS.getInstruction() << "\n"); + return true; + } + + if (IC.isNever()) { + DEBUG(dbgs() << " NOT Inlining: cost=never" + << ", Call: " << *CS.getInstruction() << "\n"); + return false; + } + + Function *Caller = CS.getCaller(); + if (!IC) { + DEBUG(dbgs() << " NOT Inlining: cost=" << IC.getCost() + << ", thres=" << (IC.getCostDelta() + IC.getCost()) + << ", Call: " << *CS.getInstruction() << "\n"); + return false; + } + + // Try to detect the case where the current inlining candidate caller (call + // it B) is a static or linkonce-ODR function and is an inlining candidate + // elsewhere, and the current candidate callee (call it C) is large enough + // that inlining it into B would make B too big to inline later. In these + // circumstances it may be best not to inline C into B, but to inline B into + // its callers. + // + // This only applies to static and linkonce-ODR functions because those are + // expected to be available for inlining in the translation units where they + // are used. Thus we will always have the opportunity to make local inlining + // decisions. Importantly the linkonce-ODR linkage covers inline functions + // and templates in C++. + // + // FIXME: All of this logic should be sunk into getInlineCost. It relies on + // the internal implementation of the inline cost metrics rather than + // treating them as truly abstract units etc. + if (Caller->hasLocalLinkage() || + Caller->getLinkage() == GlobalValue::LinkOnceODRLinkage) { + int TotalSecondaryCost = 0; + // The candidate cost to be imposed upon the current function. + int CandidateCost = IC.getCost() - (InlineConstants::CallPenalty + 1); + // This bool tracks what happens if we do NOT inline C into B. + bool callerWillBeRemoved = Caller->hasLocalLinkage(); + // This bool tracks what happens if we DO inline C into B. + bool inliningPreventsSomeOuterInline = false; + for (Value::use_iterator I = Caller->use_begin(), E =Caller->use_end(); + I != E; ++I) { + CallSite CS2(*I); + + // If this isn't a call to Caller (it could be some other sort + // of reference) skip it. Such references will prevent the caller + // from being removed. + if (!CS2 || CS2.getCalledFunction() != Caller) { + callerWillBeRemoved = false; + continue; + } + + InlineCost IC2 = getInlineCost(CS2); + ++NumCallerCallersAnalyzed; + if (!IC2) { + callerWillBeRemoved = false; + continue; + } + if (IC2.isAlways()) + continue; + + // See if inlining or original callsite would erase the cost delta of + // this callsite. We subtract off the penalty for the call instruction, + // which we would be deleting. + if (IC2.getCostDelta() <= CandidateCost) { + inliningPreventsSomeOuterInline = true; + TotalSecondaryCost += IC2.getCost(); + } + } + // If all outer calls to Caller would get inlined, the cost for the last + // one is set very low by getInlineCost, in anticipation that Caller will + // be removed entirely. We did not account for this above unless there + // is only one caller of Caller. + if (callerWillBeRemoved && Caller->use_begin() != Caller->use_end()) + TotalSecondaryCost += InlineConstants::LastCallToStaticBonus; + + if (inliningPreventsSomeOuterInline && TotalSecondaryCost < IC.getCost()) { + DEBUG(dbgs() << " NOT Inlining: " << *CS.getInstruction() << + " Cost = " << IC.getCost() << + ", outer Cost = " << TotalSecondaryCost << '\n'); + return false; + } + } + + DEBUG(dbgs() << " Inlining: cost=" << IC.getCost() + << ", thres=" << (IC.getCostDelta() + IC.getCost()) + << ", Call: " << *CS.getInstruction() << '\n'); + return true; +} + +/// InlineHistoryIncludes - Return true if the specified inline history ID +/// indicates an inline history that includes the specified function. +static bool InlineHistoryIncludes(Function *F, int InlineHistoryID, + const SmallVectorImpl<std::pair<Function*, int> > &InlineHistory) { + while (InlineHistoryID != -1) { + assert(unsigned(InlineHistoryID) < InlineHistory.size() && + "Invalid inline history ID"); + if (InlineHistory[InlineHistoryID].first == F) + return true; + InlineHistoryID = InlineHistory[InlineHistoryID].second; + } + return false; +} + +bool Inliner::runOnSCC(CallGraphSCC &SCC) { + CallGraph &CG = getAnalysis<CallGraph>(); + const DataLayout *TD = getAnalysisIfAvailable<DataLayout>(); + const TargetLibraryInfo *TLI = getAnalysisIfAvailable<TargetLibraryInfo>(); + + SmallPtrSet<Function*, 8> SCCFunctions; + DEBUG(dbgs() << "Inliner visiting SCC:"); + for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { + Function *F = (*I)->getFunction(); + if (F) SCCFunctions.insert(F); + DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE")); + } + + // Scan through and identify all call sites ahead of time so that we only + // inline call sites in the original functions, not call sites that result + // from inlining other functions. + SmallVector<std::pair<CallSite, int>, 16> CallSites; + + // When inlining a callee produces new call sites, we want to keep track of + // the fact that they were inlined from the callee. This allows us to avoid + // infinite inlining in some obscure cases. To represent this, we use an + // index into the InlineHistory vector. + SmallVector<std::pair<Function*, int>, 8> InlineHistory; + + for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { + Function *F = (*I)->getFunction(); + if (!F) continue; + + for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) + for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { + CallSite CS(cast<Value>(I)); + // If this isn't a call, or it is a call to an intrinsic, it can + // never be inlined. + if (!CS || isa<IntrinsicInst>(I)) + continue; + + // If this is a direct call to an external function, we can never inline + // it. If it is an indirect call, inlining may resolve it to be a + // direct call, so we keep it. + if (CS.getCalledFunction() && CS.getCalledFunction()->isDeclaration()) + continue; + + CallSites.push_back(std::make_pair(CS, -1)); + } + } + + DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n"); + + // If there are no calls in this function, exit early. + if (CallSites.empty()) + return false; + + // Now that we have all of the call sites, move the ones to functions in the + // current SCC to the end of the list. + unsigned FirstCallInSCC = CallSites.size(); + for (unsigned i = 0; i < FirstCallInSCC; ++i) + if (Function *F = CallSites[i].first.getCalledFunction()) + if (SCCFunctions.count(F)) + std::swap(CallSites[i--], CallSites[--FirstCallInSCC]); + + + InlinedArrayAllocasTy InlinedArrayAllocas; + InlineFunctionInfo InlineInfo(&CG, TD); + + // Now that we have all of the call sites, loop over them and inline them if + // it looks profitable to do so. + bool Changed = false; + bool LocalChange; + do { + LocalChange = false; + // Iterate over the outer loop because inlining functions can cause indirect + // calls to become direct calls. + for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) { + CallSite CS = CallSites[CSi].first; + + Function *Caller = CS.getCaller(); + Function *Callee = CS.getCalledFunction(); + + // If this call site is dead and it is to a readonly function, we should + // just delete the call instead of trying to inline it, regardless of + // size. This happens because IPSCCP propagates the result out of the + // call and then we're left with the dead call. + if (isInstructionTriviallyDead(CS.getInstruction(), TLI)) { + DEBUG(dbgs() << " -> Deleting dead call: " + << *CS.getInstruction() << "\n"); + // Update the call graph by deleting the edge from Callee to Caller. + CG[Caller]->removeCallEdgeFor(CS); + CS.getInstruction()->eraseFromParent(); + ++NumCallsDeleted; + } else { + // We can only inline direct calls to non-declarations. + if (Callee == 0 || Callee->isDeclaration()) continue; + + // If this call site was obtained by inlining another function, verify + // that the include path for the function did not include the callee + // itself. If so, we'd be recursively inlining the same function, + // which would provide the same callsites, which would cause us to + // infinitely inline. + int InlineHistoryID = CallSites[CSi].second; + if (InlineHistoryID != -1 && + InlineHistoryIncludes(Callee, InlineHistoryID, InlineHistory)) + continue; + + + // If the policy determines that we should inline this function, + // try to do so. + if (!shouldInline(CS)) + continue; + + // Attempt to inline the function. + if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas, + InlineHistoryID, InsertLifetime, TD)) + continue; + ++NumInlined; + + // If inlining this function gave us any new call sites, throw them + // onto our worklist to process. They are useful inline candidates. + if (!InlineInfo.InlinedCalls.empty()) { + // Create a new inline history entry for this, so that we remember + // that these new callsites came about due to inlining Callee. + int NewHistoryID = InlineHistory.size(); + InlineHistory.push_back(std::make_pair(Callee, InlineHistoryID)); + + for (unsigned i = 0, e = InlineInfo.InlinedCalls.size(); + i != e; ++i) { + Value *Ptr = InlineInfo.InlinedCalls[i]; + CallSites.push_back(std::make_pair(CallSite(Ptr), NewHistoryID)); + } + } + } + + // If we inlined or deleted the last possible call site to the function, + // delete the function body now. + if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() && + // TODO: Can remove if in SCC now. + !SCCFunctions.count(Callee) && + + // The function may be apparently dead, but if there are indirect + // callgraph references to the node, we cannot delete it yet, this + // could invalidate the CGSCC iterator. + CG[Callee]->getNumReferences() == 0) { + DEBUG(dbgs() << " -> Deleting dead function: " + << Callee->getName() << "\n"); + CallGraphNode *CalleeNode = CG[Callee]; + + // Remove any call graph edges from the callee to its callees. + CalleeNode->removeAllCalledFunctions(); + + // Removing the node for callee from the call graph and delete it. + delete CG.removeFunctionFromModule(CalleeNode); + ++NumDeleted; + } + + // Remove this call site from the list. If possible, use + // swap/pop_back for efficiency, but do not use it if doing so would + // move a call site to a function in this SCC before the + // 'FirstCallInSCC' barrier. + if (SCC.isSingular()) { + CallSites[CSi] = CallSites.back(); + CallSites.pop_back(); + } else { + CallSites.erase(CallSites.begin()+CSi); + } + --CSi; + + Changed = true; + LocalChange = true; + } + } while (LocalChange); + + return Changed; +} + +// doFinalization - Remove now-dead linkonce functions at the end of +// processing to avoid breaking the SCC traversal. +bool Inliner::doFinalization(CallGraph &CG) { + return removeDeadFunctions(CG); +} + +/// removeDeadFunctions - Remove dead functions that are not included in +/// DNR (Do Not Remove) list. +bool Inliner::removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly) { + SmallVector<CallGraphNode*, 16> FunctionsToRemove; + + // Scan for all of the functions, looking for ones that should now be removed + // from the program. Insert the dead ones in the FunctionsToRemove set. + for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) { + CallGraphNode *CGN = I->second; + Function *F = CGN->getFunction(); + if (!F || F->isDeclaration()) + continue; + + // Handle the case when this function is called and we only want to care + // about always-inline functions. This is a bit of a hack to share code + // between here and the InlineAlways pass. + if (AlwaysInlineOnly && + !F->getAttributes().hasAttribute(AttributeSet::FunctionIndex, + Attribute::AlwaysInline)) + continue; + + // If the only remaining users of the function are dead constants, remove + // them. + F->removeDeadConstantUsers(); + + if (!F->isDefTriviallyDead()) + continue; + + // Remove any call graph edges from the function to its callees. + CGN->removeAllCalledFunctions(); + + // Remove any edges from the external node to the function's call graph + // node. These edges might have been made irrelegant due to + // optimization of the program. + CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN); + + // Removing the node for callee from the call graph and delete it. + FunctionsToRemove.push_back(CGN); + } + if (FunctionsToRemove.empty()) + return false; + + // Now that we know which functions to delete, do so. We didn't want to do + // this inline, because that would invalidate our CallGraph::iterator + // objects. :( + // + // Note that it doesn't matter that we are iterating over a non-stable order + // here to do this, it doesn't matter which order the functions are deleted + // in. + array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end()); + FunctionsToRemove.erase(std::unique(FunctionsToRemove.begin(), + FunctionsToRemove.end()), + FunctionsToRemove.end()); + for (SmallVectorImpl<CallGraphNode *>::iterator I = FunctionsToRemove.begin(), + E = FunctionsToRemove.end(); + I != E; ++I) { + delete CG.removeFunctionFromModule(*I); + ++NumDeleted; + } + return true; +} |