diff options
-rw-r--r-- | lib/Transforms/IPO/MergeFunctions.cpp | 76 |
1 files changed, 45 insertions, 31 deletions
diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp index cefed1a..5d838f9 100644 --- a/lib/Transforms/IPO/MergeFunctions.cpp +++ b/lib/Transforms/IPO/MergeFunctions.cpp @@ -63,6 +63,7 @@ #include "llvm/Support/ValueHandle.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetData.h" +#include <vector> using namespace llvm; STATISTIC(NumFunctionsMerged, "Number of functions merged"); @@ -82,7 +83,8 @@ namespace { private: /// MergeTwoFunctions - Merge two equivalent functions. Upon completion, G - /// is deleted. + /// may be deleted, or may be converted into a thunk. In either case, it + /// should never be visited again. void MergeTwoFunctions(Function *F, Function *G) const; /// WriteThunk - Replace G with a simple tail call to bitcast(F). Also @@ -598,41 +600,53 @@ struct MergeFunctionsEqualityInfo { }; bool MergeFunctions::runOnModule(Module &M) { - bool Changed = false; - - TD = getAnalysisIfAvailable<TargetData>(); - typedef DenseSet<ComparableFunction *, MergeFunctionsEqualityInfo> FnSetType; - FnSetType FnSet; - for (Module::iterator F = M.begin(), E = M.end(); F != E;) { - if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) { - ++F; - continue; - } - - ComparableFunction *NewF = new ComparableFunction(F, TD); - ++F; - std::pair<FnSetType::iterator, bool> Result = FnSet.insert(NewF); - if (!Result.second) { - ComparableFunction *&OldF = *Result.first; - assert(OldF && "Expected a hash collision"); - - // NewF will be deleted in favour of OldF unless NewF is strong and OldF - // is weak in which case swap them to keep the strong definition. - if (OldF->Func->isWeakForLinker() && !NewF->Func->isWeakForLinker()) - std::swap(OldF, NewF); + bool Changed = false; + TD = getAnalysisIfAvailable<TargetData>(); - DEBUG(dbgs() << " " << OldF->Func->getName() << " == " - << NewF->Func->getName() << '\n'); + std::vector<Function *> Funcs; + for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) { + if (!F->isDeclaration() && !F->hasAvailableExternallyLinkage()) + Funcs.push_back(F); + } - Changed = true; - Function *DeleteF = NewF->Func; - delete NewF; - MergeTwoFunctions(OldF->Func, DeleteF); + bool LocalChanged; + do { + LocalChanged = false; + + FnSetType FnSet; + for (unsigned i = 0, e = Funcs.size(); i != e;) { + Function *F = Funcs[i]; + ComparableFunction *NewF = new ComparableFunction(F, TD); + std::pair<FnSetType::iterator, bool> Result = FnSet.insert(NewF); + if (!Result.second) { + ComparableFunction *&OldF = *Result.first; + assert(OldF && "Expected a hash collision"); + + // NewF will be deleted in favour of OldF unless NewF is strong and + // OldF is weak in which case swap them to keep the strong definition. + + if (OldF->Func->isWeakForLinker() && !NewF->Func->isWeakForLinker()) + std::swap(OldF, NewF); + + DEBUG(dbgs() << " " << OldF->Func->getName() << " == " + << NewF->Func->getName() << '\n'); + + Funcs.erase(Funcs.begin() + i); + --e; + + Function *DeleteF = NewF->Func; + delete NewF; + MergeTwoFunctions(OldF->Func, DeleteF); + LocalChanged = true; + Changed = true; + } else { + ++i; + } } - } + DeleteContainerPointers(FnSet); + } while (LocalChanged); - DeleteContainerPointers(FnSet); return Changed; } |