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diff --git a/contrib/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/contrib/llvm/lib/Transforms/IPO/MergeFunctions.cpp
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+//===- 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. If both functions are
+// overridable, we move the functionality into a new internal function and
+// leave two overridable thunks to it.
+//
+//===----------------------------------------------------------------------===//
+//
+// Future work:
+//
+// * 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.
+//
+// * use SCC to cut down on pair-wise comparisons and solve larger cycles.
+//
+// The current implementation loops over a pair-wise comparison of all
+// functions in the program where the two functions in the pair are treated as
+// assumed to be equal until proven otherwise. We could both use fewer
+// comparisons and optimize more complex cases if we used strongly connected
+// components of the call graph.
+//
+// * be smarter about bitcast.
+//
+// In order to fold functions, we will sometimes add either bitcast instructions
+// or bitcast constant expressions. Unfortunately, this can confound further
+// analysis since the two functions differ where one has a bitcast and the
+// other doesn't. We should learn to peer through bitcasts without imposing bad
+// performance properties.
+//
+// * don't emit aliases for Mach-O.
+//
+// Mach-O doesn't support aliases which means that we must avoid introducing
+// them in the bitcode on architectures which don't support them, such as
+// Mac OSX. There's a few approaches to this problem;
+// a) teach codegen to lower global aliases to thunks on platforms which don't
+// support them.
+// b) always emit thunks, and create a separate thunk-to-alias pass which
+// runs on ELF systems. This has the added benefit of transforming other
+// thunks such as those produced by a C++ frontend into aliases when legal
+// to do so.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "mergefunc"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/SmallSet.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/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetData.h"
+#include <map>
+#include <vector>
+using namespace llvm;
+
+STATISTIC(NumFunctionsMerged, "Number of functions merged");
+
+namespace {
+ class MergeFunctions : public ModulePass {
+ public:
+ static char ID; // Pass identification, replacement for typeid
+ MergeFunctions() : ModulePass(&ID) {}
+
+ bool runOnModule(Module &M);
+
+ private:
+ bool isEquivalentGEP(const GetElementPtrInst *GEP1,
+ const GetElementPtrInst *GEP2);
+
+ bool equals(const BasicBlock *BB1, const BasicBlock *BB2);
+ bool equals(const Function *F, const Function *G);
+
+ bool compare(const Value *V1, const Value *V2);
+
+ const Function *LHS, *RHS;
+ typedef DenseMap<const Value *, unsigned long> IDMap;
+ IDMap Map;
+ DenseMap<const Function *, IDMap> Domains;
+ DenseMap<const Function *, unsigned long> DomainCount;
+ TargetData *TD;
+ };
+}
+
+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();
+}
+
+/// 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()) {
+ default:
+ llvm_unreachable("Unknown type!");
+ // Fall through in Release-Asserts mode.
+ case Type::IntegerTyID:
+ case Type::OpaqueTyID:
+ // Ty1 == Ty2 would have returned true earlier.
+ return false;
+
+ 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::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::UnionTyID: {
+ const UnionType *UTy1 = cast<UnionType>(Ty1);
+ const UnionType *UTy2 = cast<UnionType>(Ty2);
+
+ // TODO: we could be fancy with union(A, union(A, B)) === union(A, B), etc.
+ if (UTy1->getNumElements() != UTy2->getNumElements())
+ return false;
+
+ for (unsigned i = 0, e = UTy1->getNumElements(); i != e; ++i) {
+ if (!isEquivalentType(UTy1->getElementType(i), UTy2->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;
+}
+
+bool MergeFunctions::isEquivalentGEP(const GetElementPtrInst *GEP1,
+ const GetElementPtrInst *GEP2) {
+ if (TD && GEP1->hasAllConstantIndices() && GEP2->hasAllConstantIndices()) {
+ SmallVector<Value *, 8> Indices1, Indices2;
+ for (GetElementPtrInst::const_op_iterator I = GEP1->idx_begin(),
+ E = GEP1->idx_end(); I != E; ++I) {
+ Indices1.push_back(*I);
+ }
+ for (GetElementPtrInst::const_op_iterator I = GEP2->idx_begin(),
+ E = GEP2->idx_end(); I != E; ++I) {
+ Indices2.push_back(*I);
+ }
+ uint64_t Offset1 = TD->getIndexedOffset(GEP1->getPointerOperandType(),
+ Indices1.data(), Indices1.size());
+ uint64_t Offset2 = TD->getIndexedOffset(GEP2->getPointerOperandType(),
+ Indices2.data(), Indices2.size());
+ return Offset1 == Offset2;
+ }
+
+ // Equivalent types aren't enough.
+ if (GEP1->getPointerOperand()->getType() !=
+ GEP2->getPointerOperand()->getType())
+ return false;
+
+ if (GEP1->getNumOperands() != GEP2->getNumOperands())
+ return false;
+
+ for (unsigned i = 0, e = GEP1->getNumOperands(); i != e; ++i) {
+ if (!compare(GEP1->getOperand(i), GEP2->getOperand(i)))
+ return false;
+ }
+
+ return true;
+}
+
+bool MergeFunctions::compare(const Value *V1, const Value *V2) {
+ if (V1 == LHS || V1 == RHS)
+ if (V2 == LHS || V2 == RHS)
+ return true;
+
+ // TODO: constant expressions in terms of LHS and RHS
+ if (isa<Constant>(V1))
+ return V1 == V2;
+
+ if (isa<InlineAsm>(V1) && isa<InlineAsm>(V2)) {
+ const InlineAsm *IA1 = cast<InlineAsm>(V1);
+ const InlineAsm *IA2 = cast<InlineAsm>(V2);
+ return IA1->getAsmString() == IA2->getAsmString() &&
+ IA1->getConstraintString() == IA2->getConstraintString();
+ }
+
+ // We enumerate constants globally and arguments, basic blocks or
+ // instructions within the function they belong to.
+ const Function *Domain1 = NULL;
+ if (const Argument *A = dyn_cast<Argument>(V1)) {
+ Domain1 = A->getParent();
+ } else if (const BasicBlock *BB = dyn_cast<BasicBlock>(V1)) {
+ Domain1 = BB->getParent();
+ } else if (const Instruction *I = dyn_cast<Instruction>(V1)) {
+ Domain1 = I->getParent()->getParent();
+ }
+
+ const Function *Domain2 = NULL;
+ if (const Argument *A = dyn_cast<Argument>(V2)) {
+ Domain2 = A->getParent();
+ } else if (const BasicBlock *BB = dyn_cast<BasicBlock>(V2)) {
+ Domain2 = BB->getParent();
+ } else if (const Instruction *I = dyn_cast<Instruction>(V2)) {
+ Domain2 = I->getParent()->getParent();
+ }
+
+ if (Domain1 != Domain2)
+ if (Domain1 != LHS && Domain1 != RHS)
+ if (Domain2 != LHS && Domain2 != RHS)
+ return false;
+
+ IDMap &Map1 = Domains[Domain1];
+ unsigned long &ID1 = Map1[V1];
+ if (!ID1)
+ ID1 = ++DomainCount[Domain1];
+
+ IDMap &Map2 = Domains[Domain2];
+ unsigned long &ID2 = Map2[V2];
+ if (!ID2)
+ ID2 = ++DomainCount[Domain2];
+
+ return ID1 == ID2;
+}
+
+bool MergeFunctions::equals(const BasicBlock *BB1, const BasicBlock *BB2) {
+ BasicBlock::const_iterator FI = BB1->begin(), FE = BB1->end();
+ BasicBlock::const_iterator GI = BB2->begin(), GE = BB2->end();
+
+ do {
+ if (!compare(FI, GI))
+ return false;
+
+ if (isa<GetElementPtrInst>(FI) && isa<GetElementPtrInst>(GI)) {
+ const GetElementPtrInst *GEP1 = cast<GetElementPtrInst>(FI);
+ const GetElementPtrInst *GEP2 = cast<GetElementPtrInst>(GI);
+
+ if (!compare(GEP1->getPointerOperand(), GEP2->getPointerOperand()))
+ return false;
+
+ if (!isEquivalentGEP(GEP1, GEP2))
+ return false;
+ } else {
+ if (!isEquivalentOperation(FI, GI))
+ return false;
+
+ for (unsigned i = 0, e = FI->getNumOperands(); i != e; ++i) {
+ Value *OpF = FI->getOperand(i);
+ Value *OpG = GI->getOperand(i);
+
+ if (!compare(OpF, OpG))
+ return false;
+
+ if (OpF->getValueID() != OpG->getValueID() ||
+ !isEquivalentType(OpF->getType(), OpG->getType()))
+ return false;
+ }
+ }
+
+ ++FI, ++GI;
+ } while (FI != FE && GI != GE);
+
+ return FI == FE && GI == GE;
+}
+
+bool MergeFunctions::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;
+
+ assert(F->arg_size() == G->arg_size() &&
+ "Identical functions have a different number of args.");
+
+ LHS = F;
+ RHS = G;
+
+ // Visit the arguments so that they get enumerated in the order they're
+ // passed in.
+ for (Function::const_arg_iterator fi = F->arg_begin(), gi = G->arg_begin(),
+ fe = F->arg_end(); fi != fe; ++fi, ++gi) {
+ if (!compare(fi, gi))
+ llvm_unreachable("Arguments repeat");
+ }
+
+ SmallVector<const BasicBlock *, 8> FBBs, GBBs;
+ SmallSet<const BasicBlock *, 128> VisitedBBs; // in terms of F.
+ FBBs.push_back(&F->getEntryBlock());
+ GBBs.push_back(&G->getEntryBlock());
+ VisitedBBs.insert(FBBs[0]);
+ while (!FBBs.empty()) {
+ const BasicBlock *FBB = FBBs.pop_back_val();
+ const BasicBlock *GBB = GBBs.pop_back_val();
+ if (!compare(FBB, GBB) || !equals(FBB, GBB)) {
+ Domains.clear();
+ DomainCount.clear();
+ return false;
+ }
+ const TerminatorInst *FTI = FBB->getTerminator();
+ const TerminatorInst *GTI = GBB->getTerminator();
+ assert(FTI->getNumSuccessors() == GTI->getNumSuccessors());
+ for (unsigned i = 0, e = FTI->getNumSuccessors(); i != e; ++i) {
+ if (!VisitedBBs.insert(FTI->getSuccessor(i)))
+ continue;
+ FBBs.push_back(FTI->getSuccessor(i));
+ GBBs.push_back(GTI->getSuccessor(i));
+ }
+ }
+
+ Domains.clear();
+ DomainCount.clear();
+ 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::CommonLinkage:
+ return ExternalStrong;
+ }
+
+ llvm_unreachable("Unknown LinkageType.");
+ return ExternalWeak;
+}
+
+static void ThunkGToF(Function *F, Function *G) {
+ if (!G->mayBeOverridden()) {
+ // Redirect direct callers of G to F.
+ Constant *BitcastF = ConstantExpr::getBitCast(F, G->getType());
+ for (Value::use_iterator UI = G->use_begin(), UE = G->use_end();
+ UI != UE;) {
+ Value::use_iterator TheIter = UI;
+ ++UI;
+ CallSite CS(*TheIter);
+ if (CS && CS.isCallee(TheIter))
+ TheIter.getUse().set(BitcastF);
+ }
+ }
+
+ Function *NewG = Function::Create(G->getFunctionType(), G->getLinkage(), "",
+ G->getParent());
+ BasicBlock *BB = BasicBlock::Create(F->getContext(), "", NewG);
+
+ SmallVector<Value *, 16> 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 {
+ Args.push_back(new BitCastInst(AI, FFTy->getParamType(i), "", BB));
+ }
+ ++i;
+ }
+
+ CallInst *CI = CallInst::Create(F, Args.begin(), Args.end(), "", BB);
+ CI->setTailCall();
+ CI->setCallingConv(F->getCallingConv());
+ if (NewG->getReturnType()->isVoidTy()) {
+ 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();
+}
+
+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())
+ continue;
+
+ FnMap[hash(F)].push_back(F);
+ }
+
+ TD = getAnalysisIfAvailable<TargetData>();
+
+ bool LocalChanged;
+ do {
+ LocalChanged = false;
+ DEBUG(dbgs() << "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(dbgs() << "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(dbgs() << " " << 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;
+}
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