// 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.
+// 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:
//
-// * 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.
//
+// * switch from n^2 pair-wise comparisons to an n-way comparison for each
+// bucket.
+//
+// * 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.
+//
+// * emit aliases for ELF
+//
+// ELF supports symbol aliases which are represented with GlobalAlias in the
+// Module, and we could emit them in the case that the addresses don't need to
+// be distinct. The problem is that not all object formats support equivalent
+// functionality. 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/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 "llvm/Target/TargetData.h"
#include <map>
#include <vector>
using namespace llvm;
STATISTIC(NumFunctionsMerged, "Number of functions merged");
namespace {
- struct VISIBILITY_HIDDEN MergeFunctions : public ModulePass {
+ /// MergeFunctions finds functions which will generate identical machine code,
+ /// by considering all pointer types to be equivalent. Once identified,
+ /// MergeFunctions will fold them by replacing a call to one to a call to a
+ /// bitcast of the other.
+ ///
+ struct MergeFunctions : public ModulePass {
static char ID; // Pass identification, replacement for typeid
- MergeFunctions() : ModulePass((intptr_t)&ID) {}
+ MergeFunctions() : ModulePass(&ID) {}
bool runOnModule(Module &M);
};
}
char MergeFunctions::ID = 0;
-static RegisterPass<MergeFunctions>
-X("mergefunc", "Merge Functions");
+INITIALIZE_PASS(MergeFunctions, "mergefunc", "Merge Functions", false, false);
ModulePass *llvm::createMergeFunctionsPass() {
return new MergeFunctions();
// ===----------------------------------------------------------------------===
// Comparison of functions
// ===----------------------------------------------------------------------===
+namespace {
+class FunctionComparator {
+public:
+ FunctionComparator(TargetData *TD, Function *F1, Function *F2)
+ : F1(F1), F2(F2), TD(TD) {}
+
+ // Compare - test whether the two functions have equivalent behaviour.
+ bool Compare();
+
+private:
+ // Compare - test whether two basic blocks have equivalent behaviour.
+ bool Compare(const BasicBlock *BB1, const BasicBlock *BB2);
+
+ // getDomain - a value's domain is its parent function if it is specific to a
+ // function, or NULL otherwise.
+ const Function *getDomain(const Value *V) const;
+
+ // Enumerate - Assign or look up previously assigned numbers for the two
+ // values, and return whether the numbers are equal. Numbers are assigned in
+ // the order visited.
+ bool Enumerate(const Value *V1, const Value *V2);
+
+ // isEquivalentOperation - Compare two Instructions for equivalence, similar
+ // to Instruction::isSameOperationAs but with modifications to the type
+ // comparison.
+ bool isEquivalentOperation(const Instruction *I1,
+ const Instruction *I2) const;
+
+ // isEquivalentGEP - Compare two GEPs for equivalent pointer arithmetic.
+ bool isEquivalentGEP(const GEPOperator *GEP1, const GEPOperator *GEP2);
+ bool isEquivalentGEP(const GetElementPtrInst *GEP1,
+ const GetElementPtrInst *GEP2) {
+ return isEquivalentGEP(cast<GEPOperator>(GEP1), cast<GEPOperator>(GEP2));
+ }
+
+ // isEquivalentType - Compare two Types, treating all pointer types as equal.
+ bool isEquivalentType(const Type *Ty1, const Type *Ty2) const;
+
+ // The two functions undergoing comparison.
+ Function *F1, *F2;
+
+ TargetData *TD;
+
+ typedef DenseMap<const Value *, unsigned long> IDMap;
+ IDMap Map;
+ DenseMap<const Function *, IDMap> Domains;
+ DenseMap<const Function *, unsigned long> DomainCount;
+};
+}
-static unsigned long hash(const Function *F) {
+/// Compute a number which is guaranteed to be equal for two equivalent
+/// functions, but is very likely to be different for different functions. This
+/// needs to be computed as efficiently as possible.
+static unsigned long ProfileFunction(const Function *F) {
const FunctionType *FTy = F->getFunctionType();
FoldingSetNodeID ID;
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) {
+bool FunctionComparator::isEquivalentType(const Type *Ty1,
+ const Type *Ty2) const {
if (Ty1 == Ty2)
return true;
if (Ty1->getTypeID() != Ty2->getTypeID())
return false;
switch(Ty1->getTypeID()) {
+ default:
+ llvm_unreachable("Unknown type!");
+ // Fall through in Release 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::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 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);
return true;
}
- case Type::ArrayTyID:
+ case Type::ArrayTyID: {
+ const ArrayType *ATy1 = cast<ArrayType>(Ty1);
+ const ArrayType *ATy2 = cast<ArrayType>(Ty2);
+ return ATy1->getNumElements() == ATy2->getNumElements() &&
+ isEquivalentType(ATy1->getElementType(), ATy2->getElementType());
+ }
case Type::VectorTyID: {
- const SequentialType *STy1 = cast<SequentialType>(Ty1);
- const SequentialType *STy2 = cast<SequentialType>(Ty2);
- return isEquivalentType(STy1->getElementType(), STy2->getElementType());
+ const VectorType *VTy1 = cast<VectorType>(Ty1);
+ const VectorType *VTy2 = cast<VectorType>(Ty2);
+ return VTy1->getNumElements() == VTy2->getNumElements() &&
+ isEquivalentType(VTy1->getElementType(), VTy2->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) {
+bool FunctionComparator::isEquivalentOperation(const Instruction *I1,
+ const Instruction *I2) const {
if (I1->getOpcode() != I2->getOpcode() ||
I1->getNumOperands() != I2->getNumOperands() ||
- !isEquivalentType(I1->getType(), I2->getType()))
+ !isEquivalentType(I1->getType(), I2->getType()) ||
+ !I1->hasSameSubclassOptionalData(I2))
return false;
// We have two instructions of identical opcode and #operands. Check to see
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.");
+/// isEquivalentGEP - determine whether two GEP operations perform the same
+/// underlying arithmetic.
+bool FunctionComparator::isEquivalentGEP(const GEPOperator *GEP1,
+ const GEPOperator *GEP2) {
+ // When we have target data, we can reduce the GEP down to the value in bytes
+ // added to the address.
+ if (TD && GEP1->hasAllConstantIndices() && GEP2->hasAllConstantIndices()) {
+ SmallVector<Value *, 8> Indices1(GEP1->idx_begin(), GEP1->idx_end());
+ SmallVector<Value *, 8> Indices2(GEP2->idx_begin(), GEP2->idx_end());
+ 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;
+ }
- // 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;
+ if (GEP1->getPointerOperand()->getType() !=
+ GEP2->getPointerOperand()->getType())
+ return false;
- // 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))
+ if (GEP1->getNumOperands() != GEP2->getNumOperands())
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();
+ for (unsigned i = 0, e = GEP1->getNumOperands(); i != e; ++i) {
+ if (!Enumerate(GEP1->getOperand(i), GEP2->getOperand(i)))
+ return false;
}
- return false;
+ return true;
}
-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;
+/// getDomain - a value's domain is its parent function if it is specific to a
+/// function, or NULL otherwise.
+const Function *FunctionComparator::getDomain(const Value *V) const {
+ if (const Argument *A = dyn_cast<Argument>(V)) {
+ return A->getParent();
+ } else if (const BasicBlock *BB = dyn_cast<BasicBlock>(V)) {
+ return BB->getParent();
+ } else if (const Instruction *I = dyn_cast<Instruction>(V)) {
+ return I->getParent()->getParent();
+ }
+ return NULL;
+}
- BasicBlock::const_iterator FI = BB1->begin(), FE = BB1->end();
- BasicBlock::const_iterator GI = BB2->begin(), GE = BB2->end();
+/// Enumerate - Compare two values used by the two functions under pair-wise
+/// comparison. If this is the first time the values are seen, they're added to
+/// the mapping so that we will detect mismatches on next use.
+bool FunctionComparator::Enumerate(const Value *V1, const Value *V2) {
+ // Check for function @f1 referring to itself and function @f2 referring to
+ // itself, or referring to each other, or both referring to either of them.
+ // They're all equivalent if the two functions are otherwise equivalent.
+ if (V1 == F1 || V1 == F2)
+ if (V2 == F1 || V2 == F2)
+ return true;
+
+ // TODO: constant expressions with GEP or references to F1 or F2.
+ 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();
+ }
- do {
- if (isa<BitCastInst>(FI)) {
- ++FI;
- continue;
- }
- if (isa<BitCastInst>(GI)) {
- ++GI;
- continue;
- }
+ // We enumerate constants globally and arguments, basic blocks or
+ // instructions within the function they belong to.
+ const Function *Domain1 = getDomain(V1);
+ const Function *Domain2 = getDomain(V2);
- if (!isEquivalentOperation(FI, GI))
+ // The domains have to either be both NULL, or F1, F2.
+ if (Domain1 != Domain2)
+ if (Domain1 != F1 && Domain1 != F2)
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;
- }
+ IDMap &Map1 = Domains[Domain1];
+ unsigned long &ID1 = Map1[V1];
+ if (!ID1)
+ ID1 = ++DomainCount[Domain1];
- // TODO: we only really care about the elements before the index
- if (FI->getOperand(0)->getType() != GI->getOperand(0)->getType())
- return false;
- }
+ IDMap &Map2 = Domains[Domain2];
+ unsigned long &ID2 = Map2[V2];
+ if (!ID2)
+ ID2 = ++DomainCount[Domain2];
- if (ValueMap[FI] == GI) {
- ++FI, ++GI;
- continue;
- }
+ return ID1 == ID2;
+}
- if (ValueMap[FI] != NULL)
- return false;
+// Compare - test whether two basic blocks have equivalent behaviour.
+bool FunctionComparator::Compare(const BasicBlock *BB1, const BasicBlock *BB2) {
+ BasicBlock::const_iterator F1I = BB1->begin(), F1E = BB1->end();
+ BasicBlock::const_iterator F2I = BB2->begin(), F2E = BB2->end();
- for (unsigned i = 0, e = FI->getNumOperands(); i != e; ++i) {
- Value *OpF = IgnoreBitcasts(FI->getOperand(i));
- Value *OpG = IgnoreBitcasts(GI->getOperand(i));
+ do {
+ if (!Enumerate(F1I, F2I))
+ return false;
- if (ValueMap[OpF] == OpG)
- continue;
+ if (const GetElementPtrInst *GEP1 = dyn_cast<GetElementPtrInst>(F1I)) {
+ const GetElementPtrInst *GEP2 = dyn_cast<GetElementPtrInst>(F2I);
+ if (!GEP2)
+ return false;
- if (ValueMap[OpF] != NULL)
+ if (!Enumerate(GEP1->getPointerOperand(), GEP2->getPointerOperand()))
return false;
- if (OpF->getValueID() != OpG->getValueID() ||
- !isEquivalentType(OpF->getType(), OpG->getType()))
+ if (!isEquivalentGEP(GEP1, GEP2))
+ return false;
+ } else {
+ if (!isEquivalentOperation(F1I, F2I))
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))
+ assert(F1I->getNumOperands() == F2I->getNumOperands());
+ for (unsigned i = 0, e = F1I->getNumOperands(); i != e; ++i) {
+ Value *OpF1 = F1I->getOperand(i);
+ Value *OpF2 = F2I->getOperand(i);
+
+ if (!Enumerate(OpF1, OpF2))
return false;
- } else {
- if (!compare(OpF, OpG))
+
+ if (OpF1->getValueID() != OpF2->getValueID() ||
+ !isEquivalentType(OpF1->getType(), OpF2->getType()))
return false;
}
-
- ValueMap[OpF] = OpG;
}
- ValueMap[FI] = GI;
- ++FI, ++GI;
- } while (FI != FE && GI != GE);
+ ++F1I, ++F2I;
+ } while (F1I != F1E && F2I != F2E);
- return FI == FE && GI == GE;
+ return F1I == F1E && F2I == F2E;
}
-static bool equals(const Function *F, const Function *G) {
+bool FunctionComparator::Compare() {
// We need to recheck everything, but check the things that weren't included
// in the hash first.
- if (F->getAttributes() != G->getAttributes())
+ if (F1->getAttributes() != F2->getAttributes())
return false;
- if (F->hasGC() != G->hasGC())
+ if (F1->hasGC() != F2->hasGC())
return false;
- if (F->hasGC() && F->getGC() != G->getGC())
+ if (F1->hasGC() && F1->getGC() != F2->getGC())
return false;
- if (F->hasSection() != G->hasSection())
+ if (F1->hasSection() != F2->hasSection())
return false;
- if (F->hasSection() && F->getSection() != G->getSection())
+ if (F1->hasSection() && F1->getSection() != F2->getSection())
return false;
- if (F->isVarArg() != G->isVarArg())
+ if (F1->isVarArg() != F2->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())
+ if (F1->getCallingConv() != F2->getCallingConv())
return false;
- if (!isEquivalentType(F->getFunctionType(), G->getFunctionType()))
+ if (!isEquivalentType(F1->getFunctionType(), F2->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() &&
+ assert(F1->arg_size() == F2->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;
+ // Visit the arguments so that they get enumerated in the order they're
+ // passed in.
+ for (Function::const_arg_iterator f1i = F1->arg_begin(),
+ f2i = F2->arg_begin(), f1e = F1->arg_end(); f1i != f1e; ++f1i, ++f2i) {
+ if (!Enumerate(f1i, f2i))
+ llvm_unreachable("Arguments repeat");
+ }
- for (DenseMap<const Value *, const Value *>::iterator
- I = SpeculationMap.begin(), E = SpeculationMap.end(); I != E; ++I) {
- if (ValueMap[I->first] != I->second)
+ // We need to do an ordered walk since the actual ordering of the blocks in
+ // the linked list is immaterial. Our walk starts at the entry block for both
+ // functions, then takes each block from each terminator in order. As an
+ // artifact, this also means that unreachable blocks are ignored.
+ SmallVector<const BasicBlock *, 8> F1BBs, F2BBs;
+ SmallSet<const BasicBlock *, 128> VisitedBBs; // in terms of F1.
+ F1BBs.push_back(&F1->getEntryBlock());
+ F2BBs.push_back(&F2->getEntryBlock());
+ VisitedBBs.insert(F1BBs[0]);
+ while (!F1BBs.empty()) {
+ const BasicBlock *F1BB = F1BBs.pop_back_val();
+ const BasicBlock *F2BB = F2BBs.pop_back_val();
+ if (!Enumerate(F1BB, F2BB) || !Compare(F1BB, F2BB))
return false;
+ const TerminatorInst *F1TI = F1BB->getTerminator();
+ const TerminatorInst *F2TI = F2BB->getTerminator();
+ assert(F1TI->getNumSuccessors() == F2TI->getNumSuccessors());
+ for (unsigned i = 0, e = F1TI->getNumSuccessors(); i != e; ++i) {
+ if (!VisitedBBs.insert(F1TI->getSuccessor(i)))
+ continue;
+ F1BBs.push_back(F1TI->getSuccessor(i));
+ F2BBs.push_back(F2TI->getSuccessor(i));
+ }
}
-
return true;
}
switch (F->getLinkage()) {
case GlobalValue::InternalLinkage:
case GlobalValue::PrivateLinkage:
+ case GlobalValue::LinkerPrivateLinkage:
return Internal;
case GlobalValue::WeakAnyLinkage:
case GlobalValue::WeakODRLinkage:
case GlobalValue::ExternalWeakLinkage:
+ case GlobalValue::LinkerPrivateWeakLinkage:
return ExternalWeak;
case GlobalValue::ExternalLinkage:
case GlobalValue::AppendingLinkage:
case GlobalValue::DLLImportLinkage:
case GlobalValue::DLLExportLinkage:
- case GlobalValue::GhostLinkage:
case GlobalValue::CommonLinkage:
return ExternalStrong;
}
}
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("", NewG);
+ BasicBlock *BB = BasicBlock::Create(F->getContext(), "", NewG);
- std::vector<Value *> Args;
+ 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())
+ if (FFTy->getParamType(i) == AI->getType()) {
Args.push_back(AI);
- else {
- Value *BCI = new BitCastInst(AI, FFTy->getParamType(i), "", BB);
- Args.push_back(BCI);
+ } 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() == Type::VoidTy) {
- ReturnInst::Create(BB);
+ 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(BCI, BB);
+ ReturnInst::Create(F->getContext(), BCI, BB);
} else {
- ReturnInst::Create(CI, BB);
+ 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) {
+ // Darwin will trigger llvm_unreachable if asked to codegen an alias.
+ return ThunkGToF(F, G);
+
+#if 0
if (!G->hasExternalLinkage() && !G->hasLocalLinkage() && !G->hasWeakLinkage())
return ThunkGToF(F, G);
GlobalAlias *GA = new GlobalAlias(
G->getType(), G->getLinkage(), "",
- F->getContext()->getConstantExprBitCast(F, G->getType()), G->getParent());
+ 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();
+#endif
}
static bool fold(std::vector<Function *> &FnVec, unsigned i, unsigned j) {
}
switch (catF) {
+ case ExternalStrong:
+ switch (catG) {
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;
- }
+ 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);
+ 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);
+ // 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);
+ ThunkGToF(F, G);
+ ThunkGToF(F, H);
- F->setLinkage(GlobalValue::InternalLinkage);
- } break;
+ 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;
- }
+ 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;
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())
+ if (F->isDeclaration())
continue;
- FnMap[hash(F)].push_back(F);
+ FnMap[ProfileFunction(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.
+ TargetData *TD = getAnalysisIfAvailable<TargetData>();
bool LocalChanged;
do {
LocalChanged = false;
- DOUT << "size: " << FnMap.size() << "\n";
+ DEBUG(dbgs() << "size: " << FnMap.size() << "\n");
for (std::map<unsigned long, std::vector<Function *> >::iterator
- I = FnMap.begin(), E = FnMap.end(); I != E; ++I) {
+ I = FnMap.begin(), E = FnMap.end(); I != E; ++I) {
std::vector<Function *> &FnVec = I->second;
- DOUT << "hash (" << I->first << "): " << FnVec.size() << "\n";
+ 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]);
+ bool isEqual = FunctionComparator(TD, FnVec[i], FnVec[j]).Compare();
- DOUT << " " << FnVec[i]->getName()
- << (isEqual ? " == " : " != ")
- << FnVec[j]->getName() << "\n";
+ DEBUG(dbgs() << " " << FnVec[i]->getName()
+ << (isEqual ? " == " : " != ")
+ << FnVec[j]->getName() << "\n");
if (isEqual) {
if (fold(FnVec, i, j)) {
projects / oota-llvm.git / blobdiff