diff options
Diffstat (limited to 'lib/Transforms/Utils/CloneFunction.cpp')
-rw-r--r-- | lib/Transforms/Utils/CloneFunction.cpp | 158 |
1 files changed, 121 insertions, 37 deletions
diff --git a/lib/Transforms/Utils/CloneFunction.cpp b/lib/Transforms/Utils/CloneFunction.cpp index 5c8f20d..09279b6 100644 --- a/lib/Transforms/Utils/CloneFunction.cpp +++ b/lib/Transforms/Utils/CloneFunction.cpp @@ -164,14 +164,13 @@ static MDNode* FindSubprogram(const Function *F, DebugInfoFinder &Finder) { // Add an operand to an existing MDNode. The new operand will be added at the // back of the operand list. -static void AddOperand(MDNode *Node, Value *Operand) { - SmallVector<Value*, 16> Operands; - for (unsigned i = 0; i < Node->getNumOperands(); i++) { - Operands.push_back(Node->getOperand(i)); - } - Operands.push_back(Operand); - MDNode *NewNode = MDNode::get(Node->getContext(), Operands); - Node->replaceAllUsesWith(NewNode); +static void AddOperand(DICompileUnit CU, DIArray SPs, Metadata *NewSP) { + SmallVector<Metadata *, 16> NewSPs; + NewSPs.reserve(SPs->getNumOperands() + 1); + for (unsigned I = 0, E = SPs->getNumOperands(); I != E; ++I) + NewSPs.push_back(SPs->getOperand(I)); + NewSPs.push_back(NewSP); + CU.replaceSubprograms(DIArray(MDNode::get(CU->getContext(), NewSPs))); } // Clone the module-level debug info associated with OldFunc. The cloned data @@ -187,7 +186,7 @@ static void CloneDebugInfoMetadata(Function *NewFunc, const Function *OldFunc, // Ensure that OldFunc appears in the map. // (if it's already there it must point to NewFunc anyway) VMap[OldFunc] = NewFunc; - DISubprogram NewSubprogram(MapValue(OldSubprogramMDNode, VMap)); + DISubprogram NewSubprogram(MapMetadata(OldSubprogramMDNode, VMap)); for (DICompileUnit CU : Finder.compile_units()) { DIArray Subprograms(CU.getSubprograms()); @@ -196,7 +195,8 @@ static void CloneDebugInfoMetadata(Function *NewFunc, const Function *OldFunc, // also contain the new one. for (unsigned i = 0; i < Subprograms.getNumElements(); i++) { if ((MDNode*)Subprograms.getElement(i) == OldSubprogramMDNode) { - AddOperand(Subprograms, NewSubprogram); + AddOperand(CU, Subprograms, NewSubprogram); + break; } } } @@ -260,21 +260,36 @@ namespace { const char *NameSuffix; ClonedCodeInfo *CodeInfo; const DataLayout *DL; + CloningDirector *Director; + ValueMapTypeRemapper *TypeMapper; + ValueMaterializer *Materializer; + public: PruningFunctionCloner(Function *newFunc, const Function *oldFunc, ValueToValueMapTy &valueMap, bool moduleLevelChanges, const char *nameSuffix, ClonedCodeInfo *codeInfo, - const DataLayout *DL) + const DataLayout *DL, + CloningDirector *Director) : NewFunc(newFunc), OldFunc(oldFunc), VMap(valueMap), ModuleLevelChanges(moduleLevelChanges), - NameSuffix(nameSuffix), CodeInfo(codeInfo), DL(DL) { + NameSuffix(nameSuffix), CodeInfo(codeInfo), DL(DL), + Director(Director) { + // These are optional components. The Director may return null. + if (Director) { + TypeMapper = Director->getTypeRemapper(); + Materializer = Director->getValueMaterializer(); + } else { + TypeMapper = nullptr; + Materializer = nullptr; + } } /// CloneBlock - The specified block is found to be reachable, clone it and /// anything that it can reach. - void CloneBlock(const BasicBlock *BB, + void CloneBlock(const BasicBlock *BB, + BasicBlock::const_iterator StartingInst, std::vector<const BasicBlock*> &ToClone); }; } @@ -282,6 +297,7 @@ namespace { /// CloneBlock - The specified block is found to be reachable, clone it and /// anything that it can reach. void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, + BasicBlock::const_iterator StartingInst, std::vector<const BasicBlock*> &ToClone){ WeakVH &BBEntry = VMap[BB]; @@ -307,21 +323,39 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, const_cast<BasicBlock*>(BB)); VMap[OldBBAddr] = BlockAddress::get(NewFunc, NewBB); } - bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false; - + // Loop over all instructions, and copy them over, DCE'ing as we go. This // loop doesn't include the terminator. - for (BasicBlock::const_iterator II = BB->begin(), IE = --BB->end(); + for (BasicBlock::const_iterator II = StartingInst, IE = --BB->end(); II != IE; ++II) { + // If the "Director" remaps the instruction, don't clone it. + if (Director) { + CloningDirector::CloningAction Action + = Director->handleInstruction(VMap, II, NewBB); + // If the cloning director says stop, we want to stop everything, not + // just break out of the loop (which would cause the terminator to be + // cloned). The cloning director is responsible for inserting a proper + // terminator into the new basic block in this case. + if (Action == CloningDirector::StopCloningBB) + return; + // If the cloning director says skip, continue to the next instruction. + // In this case, the cloning director is responsible for mapping the + // skipped instruction to some value that is defined in the new + // basic block. + if (Action == CloningDirector::SkipInstruction) + continue; + } + Instruction *NewInst = II->clone(); // Eagerly remap operands to the newly cloned instruction, except for PHI // nodes for which we defer processing until we update the CFG. if (!isa<PHINode>(NewInst)) { RemapInstruction(NewInst, VMap, - ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges); + ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges, + TypeMapper, Materializer); // If we can simplify this instruction to some other value, simply add // a mapping to that value rather than inserting a new instruction into @@ -354,6 +388,18 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, // Finally, clone over the terminator. const TerminatorInst *OldTI = BB->getTerminator(); bool TerminatorDone = false; + if (Director) { + CloningDirector::CloningAction Action + = Director->handleInstruction(VMap, OldTI, NewBB); + // If the cloning director says stop, we want to stop everything, not + // just break out of the loop (which would cause the terminator to be + // cloned). The cloning director is responsible for inserting a proper + // terminator into the new basic block in this case. + if (Action == CloningDirector::StopCloningBB) + return; + assert(Action != CloningDirector::SkipInstruction && + "SkipInstruction is not valid for terminators."); + } if (const BranchInst *BI = dyn_cast<BranchInst>(OldTI)) { if (BI->isConditional()) { // If the condition was a known constant in the callee... @@ -409,39 +455,55 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB, } } -/// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto, -/// except that it does some simple constant prop and DCE on the fly. The -/// effect of this is to copy significantly less code in cases where (for -/// example) a function call with constant arguments is inlined, and those -/// constant arguments cause a significant amount of code in the callee to be -/// dead. Since this doesn't produce an exact copy of the input, it can't be -/// used for things like CloneFunction or CloneModule. -void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, +/// CloneAndPruneIntoFromInst - This works like CloneAndPruneFunctionInto, except +/// that it does not clone the entire function. Instead it starts at an +/// instruction provided by the caller and copies (and prunes) only the code +/// reachable from that instruction. +void llvm::CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc, + const Instruction *StartingInst, ValueToValueMapTy &VMap, bool ModuleLevelChanges, - SmallVectorImpl<ReturnInst*> &Returns, + SmallVectorImpl<ReturnInst *> &Returns, const char *NameSuffix, ClonedCodeInfo *CodeInfo, const DataLayout *DL, - Instruction *TheCall) { + CloningDirector *Director) { assert(NameSuffix && "NameSuffix cannot be null!"); - + + ValueMapTypeRemapper *TypeMapper = nullptr; + ValueMaterializer *Materializer = nullptr; + + if (Director) { + TypeMapper = Director->getTypeRemapper(); + Materializer = Director->getValueMaterializer(); + } + #ifndef NDEBUG - for (Function::const_arg_iterator II = OldFunc->arg_begin(), - E = OldFunc->arg_end(); II != E; ++II) - assert(VMap.count(II) && "No mapping from source argument specified!"); + // If the cloning starts at the begining of the function, verify that + // the function arguments are mapped. + if (!StartingInst) + for (Function::const_arg_iterator II = OldFunc->arg_begin(), + E = OldFunc->arg_end(); II != E; ++II) + assert(VMap.count(II) && "No mapping from source argument specified!"); #endif PruningFunctionCloner PFC(NewFunc, OldFunc, VMap, ModuleLevelChanges, - NameSuffix, CodeInfo, DL); + NameSuffix, CodeInfo, DL, Director); + const BasicBlock *StartingBB; + if (StartingInst) + StartingBB = StartingInst->getParent(); + else { + StartingBB = &OldFunc->getEntryBlock(); + StartingInst = StartingBB->begin(); + } // Clone the entry block, and anything recursively reachable from it. std::vector<const BasicBlock*> CloneWorklist; - CloneWorklist.push_back(&OldFunc->getEntryBlock()); + PFC.CloneBlock(StartingBB, StartingInst, CloneWorklist); while (!CloneWorklist.empty()) { const BasicBlock *BB = CloneWorklist.back(); CloneWorklist.pop_back(); - PFC.CloneBlock(BB, CloneWorklist); + PFC.CloneBlock(BB, BB->begin(), CloneWorklist); } // Loop over all of the basic blocks in the old function. If the block was @@ -470,7 +532,8 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, // Finally, remap the terminator instructions, as those can't be remapped // until all BBs are mapped. RemapInstruction(NewBB->getTerminator(), VMap, - ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges); + ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges, + TypeMapper, Materializer); } // Defer PHI resolution until rest of function is resolved, PHI resolution @@ -569,7 +632,7 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, // and zap unconditional fall-through branches. This happen all the time when // specializing code: code specialization turns conditional branches into // uncond branches, and this code folds them. - Function::iterator Begin = cast<BasicBlock>(VMap[&OldFunc->getEntryBlock()]); + Function::iterator Begin = cast<BasicBlock>(VMap[StartingBB]); Function::iterator I = Begin; while (I != NewFunc->end()) { // Check if this block has become dead during inlining or other @@ -620,9 +683,30 @@ void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, // Make a final pass over the basic blocks from theh old function to gather // any return instructions which survived folding. We have to do this here // because we can iteratively remove and merge returns above. - for (Function::iterator I = cast<BasicBlock>(VMap[&OldFunc->getEntryBlock()]), + for (Function::iterator I = cast<BasicBlock>(VMap[StartingBB]), E = NewFunc->end(); I != E; ++I) if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator())) Returns.push_back(RI); } + + +/// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto, +/// except that it does some simple constant prop and DCE on the fly. The +/// effect of this is to copy significantly less code in cases where (for +/// example) a function call with constant arguments is inlined, and those +/// constant arguments cause a significant amount of code in the callee to be +/// dead. Since this doesn't produce an exact copy of the input, it can't be +/// used for things like CloneFunction or CloneModule. +void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, + ValueToValueMapTy &VMap, + bool ModuleLevelChanges, + SmallVectorImpl<ReturnInst*> &Returns, + const char *NameSuffix, + ClonedCodeInfo *CodeInfo, + const DataLayout *DL, + Instruction *TheCall) { + CloneAndPruneIntoFromInst(NewFunc, OldFunc, OldFunc->front().begin(), + VMap, ModuleLevelChanges, Returns, NameSuffix, + CodeInfo, DL, nullptr); +} |