//===- CodeExtractor.cpp - Pull code region into a new function -----------===// // // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements the interface to tear out a code region, such as an // individual loop or a parallel section, into a new function, replacing it with // a call to the new function. // //===----------------------------------------------------------------------===// #include "llvm/Transforms/Utils/FunctionUtils.h" #include "llvm/Constants.h" #include "llvm/DerivedTypes.h" #include "llvm/Instructions.h" #include "llvm/Intrinsics.h" #include "llvm/Module.h" #include "llvm/Pass.h" #include "llvm/Analysis/Dominators.h" #include "llvm/Analysis/LoopInfo.h" #include "llvm/Analysis/Verifier.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/ADT/StringExtras.h" #include <algorithm> #include <set> #include <iostream> using namespace llvm; // Provide a command-line option to aggregate function arguments into a struct // for functions produced by the code extrator. This is useful when converting // extracted functions to pthread-based code, as only one argument (void*) can // be passed in to pthread_create(). static cl::opt<bool> AggregateArgsOpt("aggregate-extracted-args", cl::Hidden, cl::desc("Aggregate arguments to code-extracted functions")); namespace { class CodeExtractor { typedef std::vector<Value*> Values; std::set<BasicBlock*> BlocksToExtract; DominatorSet *DS; bool AggregateArgs; unsigned NumExitBlocks; const Type *RetTy; public: CodeExtractor(DominatorSet *ds = 0, bool AggArgs = false) : DS(ds), AggregateArgs(AggArgs||AggregateArgsOpt), NumExitBlocks(~0U) {} Function *ExtractCodeRegion(const std::vector<BasicBlock*> &code); bool isEligible(const std::vector<BasicBlock*> &code); private: /// definedInRegion - Return true if the specified value is defined in the /// extracted region. bool definedInRegion(Value *V) const { if (Instruction *I = dyn_cast<Instruction>(V)) if (BlocksToExtract.count(I->getParent())) return true; return false; } /// definedInCaller - Return true if the specified value is defined in the /// function being code extracted, but not in the region being extracted. /// These values must be passed in as live-ins to the function. bool definedInCaller(Value *V) const { if (isa<Argument>(V)) return true; if (Instruction *I = dyn_cast<Instruction>(V)) if (!BlocksToExtract.count(I->getParent())) return true; return false; } void severSplitPHINodes(BasicBlock *&Header); void splitReturnBlocks(); void findInputsOutputs(Values &inputs, Values &outputs); Function *constructFunction(const Values &inputs, const Values &outputs, BasicBlock *header, BasicBlock *newRootNode, BasicBlock *newHeader, Function *oldFunction, Module *M); void moveCodeToFunction(Function *newFunction); void emitCallAndSwitchStatement(Function *newFunction, BasicBlock *newHeader, Values &inputs, Values &outputs); }; } /// severSplitPHINodes - If a PHI node has multiple inputs from outside of the /// region, we need to split the entry block of the region so that the PHI node /// is easier to deal with. void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) { bool HasPredsFromRegion = false; unsigned NumPredsOutsideRegion = 0; if (Header != &Header->getParent()->front()) { PHINode *PN = dyn_cast<PHINode>(Header->begin()); if (!PN) return; // No PHI nodes. // If the header node contains any PHI nodes, check to see if there is more // than one entry from outside the region. If so, we need to sever the // header block into two. for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) if (BlocksToExtract.count(PN->getIncomingBlock(i))) HasPredsFromRegion = true; else ++NumPredsOutsideRegion; // If there is one (or fewer) predecessor from outside the region, we don't // need to do anything special. if (NumPredsOutsideRegion <= 1) return; } // Otherwise, we need to split the header block into two pieces: one // containing PHI nodes merging values from outside of the region, and a // second that contains all of the code for the block and merges back any // incoming values from inside of the region. BasicBlock::iterator AfterPHIs = Header->begin(); while (isa<PHINode>(AfterPHIs)) ++AfterPHIs; BasicBlock *NewBB = Header->splitBasicBlock(AfterPHIs, Header->getName()+".ce"); // We only want to code extract the second block now, and it becomes the new // header of the region. BasicBlock *OldPred = Header; BlocksToExtract.erase(OldPred); BlocksToExtract.insert(NewBB); Header = NewBB; // Okay, update dominator sets. The blocks that dominate the new one are the // blocks that dominate TIBB plus the new block itself. if (DS) { DominatorSet::DomSetType DomSet = DS->getDominators(OldPred); DomSet.insert(NewBB); // A block always dominates itself. DS->addBasicBlock(NewBB, DomSet); // Additionally, NewBB dominates all blocks in the function that are // dominated by OldPred. Function *F = Header->getParent(); for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) if (DS->properlyDominates(OldPred, I)) DS->addDominator(I, NewBB); } // Okay, now we need to adjust the PHI nodes and any branches from within the // region to go to the new header block instead of the old header block. if (HasPredsFromRegion) { PHINode *PN = cast<PHINode>(OldPred->begin()); // Loop over all of the predecessors of OldPred that are in the region, // changing them to branch to NewBB instead. for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) if (BlocksToExtract.count(PN->getIncomingBlock(i))) { TerminatorInst *TI = PN->getIncomingBlock(i)->getTerminator(); TI->replaceUsesOfWith(OldPred, NewBB); } // Okay, everthing within the region is now branching to the right block, we // just have to update the PHI nodes now, inserting PHI nodes into NewBB. for (AfterPHIs = OldPred->begin(); isa<PHINode>(AfterPHIs); ++AfterPHIs) { PHINode *PN = cast<PHINode>(AfterPHIs); // Create a new PHI node in the new region, which has an incoming value // from OldPred of PN. PHINode *NewPN = new PHINode(PN->getType(), PN->getName()+".ce", NewBB->begin()); NewPN->addIncoming(PN, OldPred); // Loop over all of the incoming value in PN, moving them to NewPN if they // are from the extracted region. for (unsigned i = 0; i != PN->getNumIncomingValues(); ++i) { if (BlocksToExtract.count(PN->getIncomingBlock(i))) { NewPN->addIncoming(PN->getIncomingValue(i), PN->getIncomingBlock(i)); PN->removeIncomingValue(i); --i; } } } } } void CodeExtractor::splitReturnBlocks() { for (std::set<BasicBlock*>::iterator I = BlocksToExtract.begin(), E = BlocksToExtract.end(); I != E; ++I) if (ReturnInst *RI = dyn_cast<ReturnInst>((*I)->getTerminator())) (*I)->splitBasicBlock(RI, (*I)->getName()+".ret"); } // findInputsOutputs - Find inputs to, outputs from the code region. // void CodeExtractor::findInputsOutputs(Values &inputs, Values &outputs) { std::set<BasicBlock*> ExitBlocks; for (std::set<BasicBlock*>::const_iterator ci = BlocksToExtract.begin(), ce = BlocksToExtract.end(); ci != ce; ++ci) { BasicBlock *BB = *ci; for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { // If a used value is defined outside the region, it's an input. If an // instruction is used outside the region, it's an output. for (User::op_iterator O = I->op_begin(), E = I->op_end(); O != E; ++O) if (definedInCaller(*O)) inputs.push_back(*O); // Consider uses of this instruction (outputs). for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ++UI) if (!definedInRegion(*UI)) { outputs.push_back(I); break; } } // for: insts // Keep track of the exit blocks from the region. TerminatorInst *TI = BB->getTerminator(); for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) if (!BlocksToExtract.count(TI->getSuccessor(i))) ExitBlocks.insert(TI->getSuccessor(i)); } // for: basic blocks NumExitBlocks = ExitBlocks.size(); // Eliminate duplicates. std::sort(inputs.begin(), inputs.end()); inputs.erase(std::unique(inputs.begin(), inputs.end()), inputs.end()); std::sort(outputs.begin(), outputs.end()); outputs.erase(std::unique(outputs.begin(), outputs.end()), outputs.end()); } /// constructFunction - make a function based on inputs and outputs, as follows: /// f(in0, ..., inN, out0, ..., outN) /// Function *CodeExtractor::constructFunction(const Values &inputs, const Values &outputs, BasicBlock *header, BasicBlock *newRootNode, BasicBlock *newHeader, Function *oldFunction, Module *M) { DEBUG(std::cerr << "inputs: " << inputs.size() << "\n"); DEBUG(std::cerr << "outputs: " << outputs.size() << "\n"); // This function returns unsigned, outputs will go back by reference. switch (NumExitBlocks) { case 0: case 1: RetTy = Type::VoidTy; break; case 2: RetTy = Type::BoolTy; break; default: RetTy = Type::UShortTy; break; } std::vector<const Type*> paramTy; // Add the types of the input values to the function's argument list for (Values::const_iterator i = inputs.begin(), e = inputs.end(); i != e; ++i) { const Value *value = *i; DEBUG(std::cerr << "value used in func: " << *value << "\n"); paramTy.push_back(value->getType()); } // Add the types of the output values to the function's argument list. for (Values::const_iterator I = outputs.begin(), E = outputs.end(); I != E; ++I) { DEBUG(std::cerr << "instr used in func: " << **I << "\n"); if (AggregateArgs) paramTy.push_back((*I)->getType()); else paramTy.push_back(PointerType::get((*I)->getType())); } DEBUG(std::cerr << "Function type: " << *RetTy << " f("); DEBUG(for (std::vector<const Type*>::iterator i = paramTy.begin(), e = paramTy.end(); i != e; ++i) std::cerr << **i << ", "); DEBUG(std::cerr << ")\n"); if (AggregateArgs && (inputs.size() + outputs.size() > 0)) { PointerType *StructPtr = PointerType::get(StructType::get(paramTy)); paramTy.clear(); paramTy.push_back(StructPtr); } const FunctionType *funcType = FunctionType::get(RetTy, paramTy, false); // Create the new function Function *newFunction = new Function(funcType, GlobalValue::InternalLinkage, oldFunction->getName() + "_" + header->getName(), M); newFunction->getBasicBlockList().push_back(newRootNode); // Create an iterator to name all of the arguments we inserted. Function::arg_iterator AI = newFunction->arg_begin(); // Rewrite all users of the inputs in the extracted region to use the // arguments (or appropriate addressing into struct) instead. for (unsigned i = 0, e = inputs.size(); i != e; ++i) { Value *RewriteVal; if (AggregateArgs) { std::vector<Value*> Indices; Indices.push_back(Constant::getNullValue(Type::UIntTy)); Indices.push_back(ConstantUInt::get(Type::UIntTy, i)); std::string GEPname = "gep_" + inputs[i]->getName(); TerminatorInst *TI = newFunction->begin()->getTerminator(); GetElementPtrInst *GEP = new GetElementPtrInst(AI, Indices, GEPname, TI); RewriteVal = new LoadInst(GEP, "load" + GEPname, TI); } else RewriteVal = AI++; std::vector<User*> Users(inputs[i]->use_begin(), inputs[i]->use_end()); for (std::vector<User*>::iterator use = Users.begin(), useE = Users.end(); use != useE; ++use) if (Instruction* inst = dyn_cast<Instruction>(*use)) if (BlocksToExtract.count(inst->getParent())) inst->replaceUsesOfWith(inputs[i], RewriteVal); } // Set names for input and output arguments. if (!AggregateArgs) { AI = newFunction->arg_begin(); for (unsigned i = 0, e = inputs.size(); i != e; ++i, ++AI) AI->setName(inputs[i]->getName()); for (unsigned i = 0, e = outputs.size(); i != e; ++i, ++AI) AI->setName(outputs[i]->getName()+".out"); } // Rewrite branches to basic blocks outside of the loop to new dummy blocks // within the new function. This must be done before we lose track of which // blocks were originally in the code region. std::vector<User*> Users(header->use_begin(), header->use_end()); for (unsigned i = 0, e = Users.size(); i != e; ++i) // The BasicBlock which contains the branch is not in the region // modify the branch target to a new block if (TerminatorInst *TI = dyn_cast<TerminatorInst>(Users[i])) if (!BlocksToExtract.count(TI->getParent()) && TI->getParent()->getParent() == oldFunction) TI->replaceUsesOfWith(header, newHeader); return newFunction; } /// emitCallAndSwitchStatement - This method sets up the caller side by adding /// the call instruction, splitting any PHI nodes in the header block as /// necessary. void CodeExtractor:: emitCallAndSwitchStatement(Function *newFunction, BasicBlock *codeReplacer, Values &inputs, Values &outputs) { // Emit a call to the new function, passing in: *pointer to struct (if // aggregating parameters), or plan inputs and allocated memory for outputs std::vector<Value*> params, StructValues, ReloadOutputs; // Add inputs as params, or to be filled into the struct for (Values::iterator i = inputs.begin(), e = inputs.end(); i != e; ++i) if (AggregateArgs) StructValues.push_back(*i); else params.push_back(*i); // Create allocas for the outputs for (Values::iterator i = outputs.begin(), e = outputs.end(); i != e; ++i) { if (AggregateArgs) { StructValues.push_back(*i); } else { AllocaInst *alloca = new AllocaInst((*i)->getType(), 0, (*i)->getName()+".loc", codeReplacer->getParent()->begin()->begin()); ReloadOutputs.push_back(alloca); params.push_back(alloca); } } AllocaInst *Struct = 0; if (AggregateArgs && (inputs.size() + outputs.size() > 0)) { std::vector<const Type*> ArgTypes; for (Values::iterator v = StructValues.begin(), ve = StructValues.end(); v != ve; ++v) ArgTypes.push_back((*v)->getType()); // Allocate a struct at the beginning of this function Type *StructArgTy = StructType::get(ArgTypes); Struct = new AllocaInst(StructArgTy, 0, "structArg", codeReplacer->getParent()->begin()->begin()); params.push_back(Struct); for (unsigned i = 0, e = inputs.size(); i != e; ++i) { std::vector<Value*> Indices; Indices.push_back(Constant::getNullValue(Type::UIntTy)); Indices.push_back(ConstantUInt::get(Type::UIntTy, i)); GetElementPtrInst *GEP = new GetElementPtrInst(Struct, Indices, "gep_" + StructValues[i]->getName()); codeReplacer->getInstList().push_back(GEP); StoreInst *SI = new StoreInst(StructValues[i], GEP); codeReplacer->getInstList().push_back(SI); } } // Emit the call to the function CallInst *call = new CallInst(newFunction, params, NumExitBlocks > 1 ? "targetBlock" : ""); codeReplacer->getInstList().push_back(call); Function::arg_iterator OutputArgBegin = newFunction->arg_begin(); unsigned FirstOut = inputs.size(); if (!AggregateArgs) std::advance(OutputArgBegin, inputs.size()); // Reload the outputs passed in by reference for (unsigned i = 0, e = outputs.size(); i != e; ++i) { Value *Output = 0; if (AggregateArgs) { std::vector<Value*> Indices; Indices.push_back(Constant::getNullValue(Type::UIntTy)); Indices.push_back(ConstantUInt::get(Type::UIntTy, FirstOut + i)); GetElementPtrInst *GEP = new GetElementPtrInst(Struct, Indices, "gep_reload_" + outputs[i]->getName()); codeReplacer->getInstList().push_back(GEP); Output = GEP; } else { Output = ReloadOutputs[i]; } LoadInst *load = new LoadInst(Output, outputs[i]->getName()+".reload"); codeReplacer->getInstList().push_back(load); std::vector<User*> Users(outputs[i]->use_begin(), outputs[i]->use_end()); for (unsigned u = 0, e = Users.size(); u != e; ++u) { Instruction *inst = cast<Instruction>(Users[u]); if (!BlocksToExtract.count(inst->getParent())) inst->replaceUsesOfWith(outputs[i], load); } } // Now we can emit a switch statement using the call as a value. SwitchInst *TheSwitch = new SwitchInst(ConstantUInt::getNullValue(Type::UShortTy), codeReplacer, 0, codeReplacer); // Since there may be multiple exits from the original region, make the new // function return an unsigned, switch on that number. This loop iterates // over all of the blocks in the extracted region, updating any terminator // instructions in the to-be-extracted region that branch to blocks that are // not in the region to be extracted. std::map<BasicBlock*, BasicBlock*> ExitBlockMap; unsigned switchVal = 0; for (std::set<BasicBlock*>::const_iterator i = BlocksToExtract.begin(), e = BlocksToExtract.end(); i != e; ++i) { TerminatorInst *TI = (*i)->getTerminator(); for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) if (!BlocksToExtract.count(TI->getSuccessor(i))) { BasicBlock *OldTarget = TI->getSuccessor(i); // add a new basic block which returns the appropriate value BasicBlock *&NewTarget = ExitBlockMap[OldTarget]; if (!NewTarget) { // If we don't already have an exit stub for this non-extracted // destination, create one now! NewTarget = new BasicBlock(OldTarget->getName() + ".exitStub", newFunction); unsigned SuccNum = switchVal++; Value *brVal = 0; switch (NumExitBlocks) { case 0: case 1: break; // No value needed. case 2: // Conditional branch, return a bool brVal = SuccNum ? ConstantBool::False : ConstantBool::True; break; default: brVal = ConstantUInt::get(Type::UShortTy, SuccNum); break; } ReturnInst *NTRet = new ReturnInst(brVal, NewTarget); // Update the switch instruction. TheSwitch->addCase(ConstantUInt::get(Type::UShortTy, SuccNum), OldTarget); // Restore values just before we exit Function::arg_iterator OAI = OutputArgBegin; for (unsigned out = 0, e = outputs.size(); out != e; ++out) { // For an invoke, the normal destination is the only one that is // dominated by the result of the invocation BasicBlock *DefBlock = cast<Instruction>(outputs[out])->getParent(); bool DominatesDef = true; if (InvokeInst *Invoke = dyn_cast<InvokeInst>(outputs[out])) { DefBlock = Invoke->getNormalDest(); // Make sure we are looking at the original successor block, not // at a newly inserted exit block, which won't be in the dominator // info. for (std::map<BasicBlock*, BasicBlock*>::iterator I = ExitBlockMap.begin(), E = ExitBlockMap.end(); I != E; ++I) if (DefBlock == I->second) { DefBlock = I->first; break; } // In the extract block case, if the block we are extracting ends // with an invoke instruction, make sure that we don't emit a // store of the invoke value for the unwind block. if (!DS && DefBlock != OldTarget) DominatesDef = false; } if (DS) DominatesDef = DS->dominates(DefBlock, OldTarget); if (DominatesDef) { if (AggregateArgs) { std::vector<Value*> Indices; Indices.push_back(Constant::getNullValue(Type::UIntTy)); Indices.push_back(ConstantUInt::get(Type::UIntTy,FirstOut+out)); GetElementPtrInst *GEP = new GetElementPtrInst(OAI, Indices, "gep_" + outputs[out]->getName(), NTRet); new StoreInst(outputs[out], GEP, NTRet); } else { new StoreInst(outputs[out], OAI, NTRet); } } // Advance output iterator even if we don't emit a store if (!AggregateArgs) ++OAI; } } // rewrite the original branch instruction with this new target TI->setSuccessor(i, NewTarget); } } // Now that we've done the deed, simplify the switch instruction. const Type *OldFnRetTy = TheSwitch->getParent()->getParent()->getReturnType(); switch (NumExitBlocks) { case 0: // There are no successors (the block containing the switch itself), which // means that previously this was the last part of the function, and hence // this should be rewritten as a `ret' // Check if the function should return a value if (OldFnRetTy == Type::VoidTy) { new ReturnInst(0, TheSwitch); // Return void } else if (OldFnRetTy == TheSwitch->getCondition()->getType()) { // return what we have new ReturnInst(TheSwitch->getCondition(), TheSwitch); } else { // Otherwise we must have code extracted an unwind or something, just // return whatever we want. new ReturnInst(Constant::getNullValue(OldFnRetTy), TheSwitch); } TheSwitch->getParent()->getInstList().erase(TheSwitch); break; case 1: // Only a single destination, change the switch into an unconditional // branch. new BranchInst(TheSwitch->getSuccessor(1), TheSwitch); TheSwitch->getParent()->getInstList().erase(TheSwitch); break; case 2: new BranchInst(TheSwitch->getSuccessor(1), TheSwitch->getSuccessor(2), call, TheSwitch); TheSwitch->getParent()->getInstList().erase(TheSwitch); break; default: // Otherwise, make the default destination of the switch instruction be one // of the other successors. TheSwitch->setOperand(0, call); TheSwitch->setSuccessor(0, TheSwitch->getSuccessor(NumExitBlocks)); TheSwitch->removeCase(NumExitBlocks); // Remove redundant case break; } } void CodeExtractor::moveCodeToFunction(Function *newFunction) { Function *oldFunc = (*BlocksToExtract.begin())->getParent(); Function::BasicBlockListType &oldBlocks = oldFunc->getBasicBlockList(); Function::BasicBlockListType &newBlocks = newFunction->getBasicBlockList(); for (std::set<BasicBlock*>::const_iterator i = BlocksToExtract.begin(), e = BlocksToExtract.end(); i != e; ++i) { // Delete the basic block from the old function, and the list of blocks oldBlocks.remove(*i); // Insert this basic block into the new function newBlocks.push_back(*i); } } /// ExtractRegion - Removes a loop from a function, replaces it with a call to /// new function. Returns pointer to the new function. /// /// algorithm: /// /// find inputs and outputs for the region /// /// for inputs: add to function as args, map input instr* to arg# /// for outputs: add allocas for scalars, /// add to func as args, map output instr* to arg# /// /// rewrite func to use argument #s instead of instr* /// /// for each scalar output in the function: at every exit, store intermediate /// computed result back into memory. /// Function *CodeExtractor:: ExtractCodeRegion(const std::vector<BasicBlock*> &code) { if (!isEligible(code)) return 0; // 1) Find inputs, outputs // 2) Construct new function // * Add allocas for defs, pass as args by reference // * Pass in uses as args // 3) Move code region, add call instr to func // BlocksToExtract.insert(code.begin(), code.end()); Values inputs, outputs; // Assumption: this is a single-entry code region, and the header is the first // block in the region. BasicBlock *header = code[0]; for (unsigned i = 1, e = code.size(); i != e; ++i) for (pred_iterator PI = pred_begin(code[i]), E = pred_end(code[i]); PI != E; ++PI) assert(BlocksToExtract.count(*PI) && "No blocks in this region may have entries from outside the region" " except for the first block!"); // If we have to split PHI nodes or the entry block, do so now. severSplitPHINodes(header); // If we have any return instructions in the region, split those blocks so // that the return is not in the region. splitReturnBlocks(); Function *oldFunction = header->getParent(); // This takes place of the original loop BasicBlock *codeReplacer = new BasicBlock("codeRepl", oldFunction, header); // The new function needs a root node because other nodes can branch to the // head of the region, but the entry node of a function cannot have preds. BasicBlock *newFuncRoot = new BasicBlock("newFuncRoot"); newFuncRoot->getInstList().push_back(new BranchInst(header)); // Find inputs to, outputs from the code region. findInputsOutputs(inputs, outputs); // Construct new function based on inputs/outputs & add allocas for all defs. Function *newFunction = constructFunction(inputs, outputs, header, newFuncRoot, codeReplacer, oldFunction, oldFunction->getParent()); emitCallAndSwitchStatement(newFunction, codeReplacer, inputs, outputs); moveCodeToFunction(newFunction); // Loop over all of the PHI nodes in the header block, and change any // references to the old incoming edge to be the new incoming edge. for (BasicBlock::iterator I = header->begin(); isa<PHINode>(I); ++I) { PHINode *PN = cast<PHINode>(I); for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) if (!BlocksToExtract.count(PN->getIncomingBlock(i))) PN->setIncomingBlock(i, newFuncRoot); } // Look at all successors of the codeReplacer block. If any of these blocks // had PHI nodes in them, we need to update the "from" block to be the code // replacer, not the original block in the extracted region. std::vector<BasicBlock*> Succs(succ_begin(codeReplacer), succ_end(codeReplacer)); for (unsigned i = 0, e = Succs.size(); i != e; ++i) for (BasicBlock::iterator I = Succs[i]->begin(); isa<PHINode>(I); ++I) { PHINode *PN = cast<PHINode>(I); std::set<BasicBlock*> ProcessedPreds; for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) if (BlocksToExtract.count(PN->getIncomingBlock(i))) if (ProcessedPreds.insert(PN->getIncomingBlock(i)).second) PN->setIncomingBlock(i, codeReplacer); else { // There were multiple entries in the PHI for this block, now there // is only one, so remove the duplicated entries. PN->removeIncomingValue(i, false); --i; --e; } } //std::cerr << "NEW FUNCTION: " << *newFunction; // verifyFunction(*newFunction); // std::cerr << "OLD FUNCTION: " << *oldFunction; // verifyFunction(*oldFunction); DEBUG(if (verifyFunction(*newFunction)) abort()); return newFunction; } bool CodeExtractor::isEligible(const std::vector<BasicBlock*> &code) { // Deny code region if it contains allocas or vastarts. for (std::vector<BasicBlock*>::const_iterator BB = code.begin(), e=code.end(); BB != e; ++BB) for (BasicBlock::const_iterator I = (*BB)->begin(), Ie = (*BB)->end(); I != Ie; ++I) if (isa<AllocaInst>(*I)) return false; else if (const CallInst *CI = dyn_cast<CallInst>(I)) if (const Function *F = CI->getCalledFunction()) if (F->getIntrinsicID() == Intrinsic::vastart) return false; return true; } /// ExtractCodeRegion - slurp a sequence of basic blocks into a brand new /// function /// Function* llvm::ExtractCodeRegion(DominatorSet &DS, const std::vector<BasicBlock*> &code, bool AggregateArgs) { return CodeExtractor(&DS, AggregateArgs).ExtractCodeRegion(code); } /// ExtractBasicBlock - slurp a natural loop into a brand new function /// Function* llvm::ExtractLoop(DominatorSet &DS, Loop *L, bool AggregateArgs) { return CodeExtractor(&DS, AggregateArgs).ExtractCodeRegion(L->getBlocks()); } /// ExtractBasicBlock - slurp a basic block into a brand new function /// Function* llvm::ExtractBasicBlock(BasicBlock *BB, bool AggregateArgs) { std::vector<BasicBlock*> Blocks; Blocks.push_back(BB); return CodeExtractor(0, AggregateArgs).ExtractCodeRegion(Blocks); }