| //===- MergeFunctions.cpp - Merge identical functions ---------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This pass looks for equivalent functions that are mergable and folds them. |
| // |
| // A hash is computed from the function, based on its type and number of |
| // basic blocks. |
| // |
| // Once all hashes are computed, we perform an expensive equality comparison |
| // on each function pair. This takes n^2/2 comparisons per bucket, so it's |
| // important that the hash function be high quality. The equality comparison |
| // iterates through each instruction in each basic block. |
| // |
| // When a match is found, the functions are folded. We can only fold two |
| // functions when we know that the definition of one of them is not |
| // overridable. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Future work: |
| // |
| // * fold vector<T*>::push_back and vector<S*>::push_back. |
| // |
| // These two functions have different types, but in a way that doesn't matter |
| // to us. As long as we never see an S or T itself, using S* and S** is the |
| // same as using a T* and T**. |
| // |
| // * virtual functions. |
| // |
| // Many functions have their address taken by the virtual function table for |
| // the object they belong to. However, as long as it's only used for a lookup |
| // and call, this is irrelevant, and we'd like to fold such implementations. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "mergefunc" |
| #include "llvm/Transforms/IPO.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/FoldingSet.h" |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/Constants.h" |
| #include "llvm/InlineAsm.h" |
| #include "llvm/Instructions.h" |
| #include "llvm/LLVMContext.h" |
| #include "llvm/Module.h" |
| #include "llvm/Pass.h" |
| #include "llvm/Support/CallSite.h" |
| #include "llvm/Support/Compiler.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <map> |
| #include <vector> |
| using namespace llvm; |
| |
| STATISTIC(NumFunctionsMerged, "Number of functions merged"); |
| |
| namespace { |
| struct VISIBILITY_HIDDEN MergeFunctions : public ModulePass { |
| static char ID; // Pass identification, replacement for typeid |
| MergeFunctions() : ModulePass(&ID) {} |
| |
| bool runOnModule(Module &M); |
| }; |
| } |
| |
| char MergeFunctions::ID = 0; |
| static RegisterPass<MergeFunctions> |
| X("mergefunc", "Merge Functions"); |
| |
| ModulePass *llvm::createMergeFunctionsPass() { |
| return new MergeFunctions(); |
| } |
| |
| // ===----------------------------------------------------------------------=== |
| // Comparison of functions |
| // ===----------------------------------------------------------------------=== |
| |
| static unsigned long hash(const Function *F) { |
| const FunctionType *FTy = F->getFunctionType(); |
| |
| FoldingSetNodeID ID; |
| ID.AddInteger(F->size()); |
| ID.AddInteger(F->getCallingConv()); |
| ID.AddBoolean(F->hasGC()); |
| ID.AddBoolean(FTy->isVarArg()); |
| ID.AddInteger(FTy->getReturnType()->getTypeID()); |
| for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) |
| ID.AddInteger(FTy->getParamType(i)->getTypeID()); |
| return ID.ComputeHash(); |
| } |
| |
| /// IgnoreBitcasts - given a bitcast, returns the first non-bitcast found by |
| /// walking the chain of cast operands. Otherwise, returns the argument. |
| static Value* IgnoreBitcasts(Value *V) { |
| while (BitCastInst *BC = dyn_cast<BitCastInst>(V)) |
| V = BC->getOperand(0); |
| |
| return V; |
| } |
| |
| /// isEquivalentType - any two pointers are equivalent. Otherwise, standard |
| /// type equivalence rules apply. |
| static bool isEquivalentType(const Type *Ty1, const Type *Ty2) { |
| if (Ty1 == Ty2) |
| return true; |
| if (Ty1->getTypeID() != Ty2->getTypeID()) |
| return false; |
| |
| switch(Ty1->getTypeID()) { |
| case Type::VoidTyID: |
| case Type::FloatTyID: |
| case Type::DoubleTyID: |
| case Type::X86_FP80TyID: |
| case Type::FP128TyID: |
| case Type::PPC_FP128TyID: |
| case Type::LabelTyID: |
| case Type::MetadataTyID: |
| return true; |
| |
| case Type::IntegerTyID: |
| case Type::OpaqueTyID: |
| // Ty1 == Ty2 would have returned true earlier. |
| return false; |
| |
| default: |
| llvm_unreachable("Unknown type!"); |
| return false; |
| |
| case Type::PointerTyID: { |
| const PointerType *PTy1 = cast<PointerType>(Ty1); |
| const PointerType *PTy2 = cast<PointerType>(Ty2); |
| return PTy1->getAddressSpace() == PTy2->getAddressSpace(); |
| } |
| |
| case Type::StructTyID: { |
| const StructType *STy1 = cast<StructType>(Ty1); |
| const StructType *STy2 = cast<StructType>(Ty2); |
| if (STy1->getNumElements() != STy2->getNumElements()) |
| return false; |
| |
| if (STy1->isPacked() != STy2->isPacked()) |
| return false; |
| |
| for (unsigned i = 0, e = STy1->getNumElements(); i != e; ++i) { |
| if (!isEquivalentType(STy1->getElementType(i), STy2->getElementType(i))) |
| return false; |
| } |
| return true; |
| } |
| |
| case Type::FunctionTyID: { |
| const FunctionType *FTy1 = cast<FunctionType>(Ty1); |
| const FunctionType *FTy2 = cast<FunctionType>(Ty2); |
| if (FTy1->getNumParams() != FTy2->getNumParams() || |
| FTy1->isVarArg() != FTy2->isVarArg()) |
| return false; |
| |
| if (!isEquivalentType(FTy1->getReturnType(), FTy2->getReturnType())) |
| return false; |
| |
| for (unsigned i = 0, e = FTy1->getNumParams(); i != e; ++i) { |
| if (!isEquivalentType(FTy1->getParamType(i), FTy2->getParamType(i))) |
| return false; |
| } |
| return true; |
| } |
| |
| case Type::ArrayTyID: |
| case Type::VectorTyID: { |
| const SequentialType *STy1 = cast<SequentialType>(Ty1); |
| const SequentialType *STy2 = cast<SequentialType>(Ty2); |
| return isEquivalentType(STy1->getElementType(), STy2->getElementType()); |
| } |
| } |
| } |
| |
| /// isEquivalentOperation - determine whether the two operations are the same |
| /// except that pointer-to-A and pointer-to-B are equivalent. This should be |
| /// kept in sync with Instruction::isSameOperationAs. |
| static bool |
| isEquivalentOperation(const Instruction *I1, const Instruction *I2) { |
| if (I1->getOpcode() != I2->getOpcode() || |
| I1->getNumOperands() != I2->getNumOperands() || |
| !isEquivalentType(I1->getType(), I2->getType()) || |
| !I1->hasSameSubclassOptionalData(I2)) |
| return false; |
| |
| // We have two instructions of identical opcode and #operands. Check to see |
| // if all operands are the same type |
| for (unsigned i = 0, e = I1->getNumOperands(); i != e; ++i) |
| if (!isEquivalentType(I1->getOperand(i)->getType(), |
| I2->getOperand(i)->getType())) |
| return false; |
| |
| // Check special state that is a part of some instructions. |
| if (const LoadInst *LI = dyn_cast<LoadInst>(I1)) |
| return LI->isVolatile() == cast<LoadInst>(I2)->isVolatile() && |
| LI->getAlignment() == cast<LoadInst>(I2)->getAlignment(); |
| if (const StoreInst *SI = dyn_cast<StoreInst>(I1)) |
| return SI->isVolatile() == cast<StoreInst>(I2)->isVolatile() && |
| SI->getAlignment() == cast<StoreInst>(I2)->getAlignment(); |
| if (const CmpInst *CI = dyn_cast<CmpInst>(I1)) |
| return CI->getPredicate() == cast<CmpInst>(I2)->getPredicate(); |
| if (const CallInst *CI = dyn_cast<CallInst>(I1)) |
| return CI->isTailCall() == cast<CallInst>(I2)->isTailCall() && |
| CI->getCallingConv() == cast<CallInst>(I2)->getCallingConv() && |
| CI->getAttributes().getRawPointer() == |
| cast<CallInst>(I2)->getAttributes().getRawPointer(); |
| if (const InvokeInst *CI = dyn_cast<InvokeInst>(I1)) |
| return CI->getCallingConv() == cast<InvokeInst>(I2)->getCallingConv() && |
| CI->getAttributes().getRawPointer() == |
| cast<InvokeInst>(I2)->getAttributes().getRawPointer(); |
| if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(I1)) { |
| if (IVI->getNumIndices() != cast<InsertValueInst>(I2)->getNumIndices()) |
| return false; |
| for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i) |
| if (IVI->idx_begin()[i] != cast<InsertValueInst>(I2)->idx_begin()[i]) |
| return false; |
| return true; |
| } |
| if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I1)) { |
| if (EVI->getNumIndices() != cast<ExtractValueInst>(I2)->getNumIndices()) |
| return false; |
| for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i) |
| if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I2)->idx_begin()[i]) |
| return false; |
| return true; |
| } |
| |
| return true; |
| } |
| |
| static bool compare(const Value *V, const Value *U) { |
| assert(!isa<BasicBlock>(V) && !isa<BasicBlock>(U) && |
| "Must not compare basic blocks."); |
| |
| assert(isEquivalentType(V->getType(), U->getType()) && |
| "Two of the same operation have operands of different type."); |
| |
| // TODO: If the constant is an expression of F, we should accept that it's |
| // equal to the same expression in terms of G. |
| if (isa<Constant>(V)) |
| return V == U; |
| |
| // The caller has ensured that ValueMap[V] != U. Since Arguments are |
| // pre-loaded into the ValueMap, and Instructions are added as we go, we know |
| // that this can only be a mis-match. |
| if (isa<Instruction>(V) || isa<Argument>(V)) |
| return false; |
| |
| if (isa<InlineAsm>(V) && isa<InlineAsm>(U)) { |
| const InlineAsm *IAF = cast<InlineAsm>(V); |
| const InlineAsm *IAG = cast<InlineAsm>(U); |
| return IAF->getAsmString() == IAG->getAsmString() && |
| IAF->getConstraintString() == IAG->getConstraintString(); |
| } |
| |
| return false; |
| } |
| |
| static bool equals(const BasicBlock *BB1, const BasicBlock *BB2, |
| DenseMap<const Value *, const Value *> &ValueMap, |
| DenseMap<const Value *, const Value *> &SpeculationMap) { |
| // Speculatively add it anyways. If it's false, we'll notice a difference |
| // later, and this won't matter. |
| ValueMap[BB1] = BB2; |
| |
| BasicBlock::const_iterator FI = BB1->begin(), FE = BB1->end(); |
| BasicBlock::const_iterator GI = BB2->begin(), GE = BB2->end(); |
| |
| do { |
| if (isa<BitCastInst>(FI)) { |
| ++FI; |
| continue; |
| } |
| if (isa<BitCastInst>(GI)) { |
| ++GI; |
| continue; |
| } |
| |
| if (!isEquivalentOperation(FI, GI)) |
| return false; |
| |
| if (isa<GetElementPtrInst>(FI)) { |
| const GetElementPtrInst *GEPF = cast<GetElementPtrInst>(FI); |
| const GetElementPtrInst *GEPG = cast<GetElementPtrInst>(GI); |
| if (GEPF->hasAllZeroIndices() && GEPG->hasAllZeroIndices()) { |
| // It's effectively a bitcast. |
| ++FI, ++GI; |
| continue; |
| } |
| |
| // TODO: we only really care about the elements before the index |
| if (FI->getOperand(0)->getType() != GI->getOperand(0)->getType()) |
| return false; |
| } |
| |
| if (ValueMap[FI] == GI) { |
| ++FI, ++GI; |
| continue; |
| } |
| |
| if (ValueMap[FI] != NULL) |
| return false; |
| |
| for (unsigned i = 0, e = FI->getNumOperands(); i != e; ++i) { |
| Value *OpF = IgnoreBitcasts(FI->getOperand(i)); |
| Value *OpG = IgnoreBitcasts(GI->getOperand(i)); |
| |
| if (ValueMap[OpF] == OpG) |
| continue; |
| |
| if (ValueMap[OpF] != NULL) |
| return false; |
| |
| if (OpF->getValueID() != OpG->getValueID() || |
| !isEquivalentType(OpF->getType(), OpG->getType())) |
| return false; |
| |
| if (isa<PHINode>(FI)) { |
| if (SpeculationMap[OpF] == NULL) |
| SpeculationMap[OpF] = OpG; |
| else if (SpeculationMap[OpF] != OpG) |
| return false; |
| continue; |
| } else if (isa<BasicBlock>(OpF)) { |
| assert(isa<TerminatorInst>(FI) && |
| "BasicBlock referenced by non-Terminator non-PHI"); |
| // This call changes the ValueMap, hence we can't use |
| // Value *& = ValueMap[...] |
| if (!equals(cast<BasicBlock>(OpF), cast<BasicBlock>(OpG), ValueMap, |
| SpeculationMap)) |
| return false; |
| } else { |
| if (!compare(OpF, OpG)) |
| return false; |
| } |
| |
| ValueMap[OpF] = OpG; |
| } |
| |
| ValueMap[FI] = GI; |
| ++FI, ++GI; |
| } while (FI != FE && GI != GE); |
| |
| return FI == FE && GI == GE; |
| } |
| |
| static bool equals(const Function *F, const Function *G) { |
| // We need to recheck everything, but check the things that weren't included |
| // in the hash first. |
| |
| if (F->getAttributes() != G->getAttributes()) |
| return false; |
| |
| if (F->hasGC() != G->hasGC()) |
| return false; |
| |
| if (F->hasGC() && F->getGC() != G->getGC()) |
| return false; |
| |
| if (F->hasSection() != G->hasSection()) |
| return false; |
| |
| if (F->hasSection() && F->getSection() != G->getSection()) |
| return false; |
| |
| if (F->isVarArg() != G->isVarArg()) |
| return false; |
| |
| // TODO: if it's internal and only used in direct calls, we could handle this |
| // case too. |
| if (F->getCallingConv() != G->getCallingConv()) |
| return false; |
| |
| if (!isEquivalentType(F->getFunctionType(), G->getFunctionType())) |
| return false; |
| |
| DenseMap<const Value *, const Value *> ValueMap; |
| DenseMap<const Value *, const Value *> SpeculationMap; |
| ValueMap[F] = G; |
| |
| assert(F->arg_size() == G->arg_size() && |
| "Identical functions have a different number of args."); |
| |
| for (Function::const_arg_iterator fi = F->arg_begin(), gi = G->arg_begin(), |
| fe = F->arg_end(); fi != fe; ++fi, ++gi) |
| ValueMap[fi] = gi; |
| |
| if (!equals(&F->getEntryBlock(), &G->getEntryBlock(), ValueMap, |
| SpeculationMap)) |
| return false; |
| |
| for (DenseMap<const Value *, const Value *>::iterator |
| I = SpeculationMap.begin(), E = SpeculationMap.end(); I != E; ++I) { |
| if (ValueMap[I->first] != I->second) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // ===----------------------------------------------------------------------=== |
| // Folding of functions |
| // ===----------------------------------------------------------------------=== |
| |
| // Cases: |
| // * F is external strong, G is external strong: |
| // turn G into a thunk to F (1) |
| // * F is external strong, G is external weak: |
| // turn G into a thunk to F (1) |
| // * F is external weak, G is external weak: |
| // unfoldable |
| // * F is external strong, G is internal: |
| // address of G taken: |
| // turn G into a thunk to F (1) |
| // address of G not taken: |
| // make G an alias to F (2) |
| // * F is internal, G is external weak |
| // address of F is taken: |
| // turn G into a thunk to F (1) |
| // address of F is not taken: |
| // make G an alias of F (2) |
| // * F is internal, G is internal: |
| // address of F and G are taken: |
| // turn G into a thunk to F (1) |
| // address of G is not taken: |
| // make G an alias to F (2) |
| // |
| // alias requires linkage == (external,local,weak) fallback to creating a thunk |
| // external means 'externally visible' linkage != (internal,private) |
| // internal means linkage == (internal,private) |
| // weak means linkage mayBeOverridable |
| // being external implies that the address is taken |
| // |
| // 1. turn G into a thunk to F |
| // 2. make G an alias to F |
| |
| enum LinkageCategory { |
| ExternalStrong, |
| ExternalWeak, |
| Internal |
| }; |
| |
| static LinkageCategory categorize(const Function *F) { |
| switch (F->getLinkage()) { |
| case GlobalValue::InternalLinkage: |
| case GlobalValue::PrivateLinkage: |
| case GlobalValue::LinkerPrivateLinkage: |
| return Internal; |
| |
| case GlobalValue::WeakAnyLinkage: |
| case GlobalValue::WeakODRLinkage: |
| case GlobalValue::ExternalWeakLinkage: |
| return ExternalWeak; |
| |
| case GlobalValue::ExternalLinkage: |
| case GlobalValue::AvailableExternallyLinkage: |
| case GlobalValue::LinkOnceAnyLinkage: |
| case GlobalValue::LinkOnceODRLinkage: |
| case GlobalValue::AppendingLinkage: |
| case GlobalValue::DLLImportLinkage: |
| case GlobalValue::DLLExportLinkage: |
| case GlobalValue::GhostLinkage: |
| case GlobalValue::CommonLinkage: |
| return ExternalStrong; |
| } |
| |
| llvm_unreachable("Unknown LinkageType."); |
| return ExternalWeak; |
| } |
| |
| static void ThunkGToF(Function *F, Function *G) { |
| Function *NewG = Function::Create(G->getFunctionType(), G->getLinkage(), "", |
| G->getParent()); |
| BasicBlock *BB = BasicBlock::Create(F->getContext(), "", NewG); |
| |
| std::vector<Value *> Args; |
| unsigned i = 0; |
| const FunctionType *FFTy = F->getFunctionType(); |
| for (Function::arg_iterator AI = NewG->arg_begin(), AE = NewG->arg_end(); |
| AI != AE; ++AI) { |
| if (FFTy->getParamType(i) == AI->getType()) |
| Args.push_back(AI); |
| else { |
| Value *BCI = new BitCastInst(AI, FFTy->getParamType(i), "", BB); |
| Args.push_back(BCI); |
| } |
| ++i; |
| } |
| |
| CallInst *CI = CallInst::Create(F, Args.begin(), Args.end(), "", BB); |
| CI->setTailCall(); |
| CI->setCallingConv(F->getCallingConv()); |
| if (NewG->getReturnType() == Type::getVoidTy(F->getContext())) { |
| ReturnInst::Create(F->getContext(), BB); |
| } else if (CI->getType() != NewG->getReturnType()) { |
| Value *BCI = new BitCastInst(CI, NewG->getReturnType(), "", BB); |
| ReturnInst::Create(F->getContext(), BCI, BB); |
| } else { |
| ReturnInst::Create(F->getContext(), CI, BB); |
| } |
| |
| NewG->copyAttributesFrom(G); |
| NewG->takeName(G); |
| G->replaceAllUsesWith(NewG); |
| G->eraseFromParent(); |
| |
| // TODO: look at direct callers to G and make them all direct callers to F. |
| } |
| |
| static void AliasGToF(Function *F, Function *G) { |
| if (!G->hasExternalLinkage() && !G->hasLocalLinkage() && !G->hasWeakLinkage()) |
| return ThunkGToF(F, G); |
| |
| GlobalAlias *GA = new GlobalAlias( |
| G->getType(), G->getLinkage(), "", |
| ConstantExpr::getBitCast(F, G->getType()), G->getParent()); |
| F->setAlignment(std::max(F->getAlignment(), G->getAlignment())); |
| GA->takeName(G); |
| GA->setVisibility(G->getVisibility()); |
| G->replaceAllUsesWith(GA); |
| G->eraseFromParent(); |
| } |
| |
| static bool fold(std::vector<Function *> &FnVec, unsigned i, unsigned j) { |
| Function *F = FnVec[i]; |
| Function *G = FnVec[j]; |
| |
| LinkageCategory catF = categorize(F); |
| LinkageCategory catG = categorize(G); |
| |
| if (catF == ExternalWeak || (catF == Internal && catG == ExternalStrong)) { |
| std::swap(FnVec[i], FnVec[j]); |
| std::swap(F, G); |
| std::swap(catF, catG); |
| } |
| |
| switch (catF) { |
| case ExternalStrong: |
| switch (catG) { |
| case ExternalStrong: |
| case ExternalWeak: |
| ThunkGToF(F, G); |
| break; |
| case Internal: |
| if (G->hasAddressTaken()) |
| ThunkGToF(F, G); |
| else |
| AliasGToF(F, G); |
| break; |
| } |
| break; |
| |
| case ExternalWeak: { |
| assert(catG == ExternalWeak); |
| |
| // Make them both thunks to the same internal function. |
| F->setAlignment(std::max(F->getAlignment(), G->getAlignment())); |
| Function *H = Function::Create(F->getFunctionType(), F->getLinkage(), "", |
| F->getParent()); |
| H->copyAttributesFrom(F); |
| H->takeName(F); |
| F->replaceAllUsesWith(H); |
| |
| ThunkGToF(F, G); |
| ThunkGToF(F, H); |
| |
| F->setLinkage(GlobalValue::InternalLinkage); |
| } break; |
| |
| case Internal: |
| switch (catG) { |
| case ExternalStrong: |
| llvm_unreachable(0); |
| // fall-through |
| case ExternalWeak: |
| if (F->hasAddressTaken()) |
| ThunkGToF(F, G); |
| else |
| AliasGToF(F, G); |
| break; |
| case Internal: { |
| bool addrTakenF = F->hasAddressTaken(); |
| bool addrTakenG = G->hasAddressTaken(); |
| if (!addrTakenF && addrTakenG) { |
| std::swap(FnVec[i], FnVec[j]); |
| std::swap(F, G); |
| std::swap(addrTakenF, addrTakenG); |
| } |
| |
| if (addrTakenF && addrTakenG) { |
| ThunkGToF(F, G); |
| } else { |
| assert(!addrTakenG); |
| AliasGToF(F, G); |
| } |
| } break; |
| } |
| break; |
| } |
| |
| ++NumFunctionsMerged; |
| return true; |
| } |
| |
| // ===----------------------------------------------------------------------=== |
| // Pass definition |
| // ===----------------------------------------------------------------------=== |
| |
| bool MergeFunctions::runOnModule(Module &M) { |
| bool Changed = false; |
| |
| std::map<unsigned long, std::vector<Function *> > FnMap; |
| |
| for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) { |
| if (F->isDeclaration() || F->isIntrinsic()) |
| continue; |
| |
| FnMap[hash(F)].push_back(F); |
| } |
| |
| // TODO: instead of running in a loop, we could also fold functions in |
| // callgraph order. Constructing the CFG probably isn't cheaper than just |
| // running in a loop, unless it happened to already be available. |
| |
| bool LocalChanged; |
| do { |
| LocalChanged = false; |
| DEBUG(errs() << "size: " << FnMap.size() << "\n"); |
| for (std::map<unsigned long, std::vector<Function *> >::iterator |
| I = FnMap.begin(), E = FnMap.end(); I != E; ++I) { |
| std::vector<Function *> &FnVec = I->second; |
| DEBUG(errs() << "hash (" << I->first << "): " << FnVec.size() << "\n"); |
| |
| for (int i = 0, e = FnVec.size(); i != e; ++i) { |
| for (int j = i + 1; j != e; ++j) { |
| bool isEqual = equals(FnVec[i], FnVec[j]); |
| |
| DEBUG(errs() << " " << FnVec[i]->getName() |
| << (isEqual ? " == " : " != ") |
| << FnVec[j]->getName() << "\n"); |
| |
| if (isEqual) { |
| if (fold(FnVec, i, j)) { |
| LocalChanged = true; |
| FnVec.erase(FnVec.begin() + j); |
| --j, --e; |
| } |
| } |
| } |
| } |
| |
| } |
| Changed |= LocalChanged; |
| } while (LocalChanged); |
| |
| return Changed; |
| } |