1 //===- CodeExtractor.cpp - Pull code region into a new function -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the interface to tear out a code region, such as an
11 // individual loop or a parallel section, into a new function, replacing it with
12 // a call to the new function.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Transforms/Utils/FunctionUtils.h"
17 #include "llvm/Constants.h"
18 #include "llvm/DerivedTypes.h"
19 #include "llvm/Instructions.h"
20 #include "llvm/Intrinsics.h"
21 #include "llvm/Module.h"
22 #include "llvm/Pass.h"
23 #include "llvm/Analysis/Dominators.h"
24 #include "llvm/Analysis/LoopInfo.h"
25 #include "llvm/Analysis/Verifier.h"
26 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
27 #include "Support/CommandLine.h"
28 #include "Support/Debug.h"
29 #include "Support/StringExtras.h"
34 // Provide a command-line option to aggregate function arguments into a struct
35 // for functions produced by the code extrator. This is useful when converting
36 // extracted functions to pthread-based code, as only one argument (void*) can
37 // be passed in to pthread_create().
39 AggregateArgsOpt("aggregate-extracted-args", cl::Hidden,
40 cl::desc("Aggregate arguments to code-extracted functions"));
44 typedef std::vector<Value*> Values;
45 std::set<BasicBlock*> BlocksToExtract;
48 unsigned NumExitBlocks;
51 CodeExtractor(DominatorSet *ds = 0, bool AggArgs = false)
52 : DS(ds), AggregateArgs(AggregateArgsOpt), NumExitBlocks(~0U) {}
54 Function *ExtractCodeRegion(const std::vector<BasicBlock*> &code);
56 bool isEligible(const std::vector<BasicBlock*> &code);
59 /// definedInRegion - Return true if the specified value is defined in the
61 bool definedInRegion(Value *V) const {
62 if (Instruction *I = dyn_cast<Instruction>(V))
63 if (BlocksToExtract.count(I->getParent()))
68 /// definedInCaller - Return true if the specified value is defined in the
69 /// function being code extracted, but not in the region being extracted.
70 /// These values must be passed in as live-ins to the function.
71 bool definedInCaller(Value *V) const {
72 if (isa<Argument>(V)) return true;
73 if (Instruction *I = dyn_cast<Instruction>(V))
74 if (!BlocksToExtract.count(I->getParent()))
79 void severSplitPHINodes(BasicBlock *&Header);
80 void findInputsOutputs(Values &inputs, Values &outputs);
82 Function *constructFunction(const Values &inputs,
83 const Values &outputs,
85 BasicBlock *newRootNode, BasicBlock *newHeader,
86 Function *oldFunction, Module *M);
88 void moveCodeToFunction(Function *newFunction);
90 void emitCallAndSwitchStatement(Function *newFunction,
91 BasicBlock *newHeader,
98 /// severSplitPHINodes - If a PHI node has multiple inputs from outside of the
99 /// region, we need to split the entry block of the region so that the PHI node
100 /// is easier to deal with.
101 void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) {
102 bool HasPredsFromRegion = false;
103 unsigned NumPredsOutsideRegion = 0;
105 if (Header != &Header->getParent()->front()) {
106 PHINode *PN = dyn_cast<PHINode>(Header->begin());
107 if (!PN) return; // No PHI nodes.
109 // If the header node contains any PHI nodes, check to see if there is more
110 // than one entry from outside the region. If so, we need to sever the
111 // header block into two.
112 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
113 if (BlocksToExtract.count(PN->getIncomingBlock(i)))
114 HasPredsFromRegion = true;
116 ++NumPredsOutsideRegion;
118 // If there is one (or fewer) predecessor from outside the region, we don't
119 // need to do anything special.
120 if (NumPredsOutsideRegion <= 1) return;
123 // Otherwise, we need to split the header block into two pieces: one
124 // containing PHI nodes merging values from outside of the region, and a
125 // second that contains all of the code for the block and merges back any
126 // incoming values from inside of the region.
127 BasicBlock::iterator AfterPHIs = Header->begin();
128 while (isa<PHINode>(AfterPHIs)) ++AfterPHIs;
129 BasicBlock *NewBB = Header->splitBasicBlock(AfterPHIs,
130 Header->getName()+".ce");
132 // We only want to code extract the second block now, and it becomes the new
133 // header of the region.
134 BasicBlock *OldPred = Header;
135 BlocksToExtract.erase(OldPred);
136 BlocksToExtract.insert(NewBB);
139 // Okay, update dominator sets. The blocks that dominate the new one are the
140 // blocks that dominate TIBB plus the new block itself.
142 DominatorSet::DomSetType DomSet = DS->getDominators(OldPred);
143 DomSet.insert(NewBB); // A block always dominates itself.
144 DS->addBasicBlock(NewBB, DomSet);
146 // Additionally, NewBB dominates all blocks in the function that are
147 // dominated by OldPred.
148 Function *F = Header->getParent();
149 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
150 if (DS->properlyDominates(OldPred, I))
151 DS->addDominator(I, NewBB);
154 // Okay, now we need to adjust the PHI nodes and any branches from within the
155 // region to go to the new header block instead of the old header block.
156 if (HasPredsFromRegion) {
157 PHINode *PN = cast<PHINode>(OldPred->begin());
158 // Loop over all of the predecessors of OldPred that are in the region,
159 // changing them to branch to NewBB instead.
160 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
161 if (BlocksToExtract.count(PN->getIncomingBlock(i))) {
162 TerminatorInst *TI = PN->getIncomingBlock(i)->getTerminator();
163 TI->replaceUsesOfWith(OldPred, NewBB);
166 // Okay, everthing within the region is now branching to the right block, we
167 // just have to update the PHI nodes now, inserting PHI nodes into NewBB.
168 for (AfterPHIs = OldPred->begin();
169 PHINode *PN = dyn_cast<PHINode>(AfterPHIs); ++AfterPHIs) {
170 // Create a new PHI node in the new region, which has an incoming value
171 // from OldPred of PN.
172 PHINode *NewPN = new PHINode(PN->getType(), PN->getName()+".ce",
174 NewPN->addIncoming(PN, OldPred);
176 // Loop over all of the incoming value in PN, moving them to NewPN if they
177 // are from the extracted region.
178 for (unsigned i = 0; i != PN->getNumIncomingValues(); ++i) {
179 if (BlocksToExtract.count(PN->getIncomingBlock(i))) {
180 NewPN->addIncoming(PN->getIncomingValue(i), PN->getIncomingBlock(i));
181 PN->removeIncomingValue(i);
188 verifyFunction(*NewBB->getParent());
191 // findInputsOutputs - Find inputs to, outputs from the code region.
193 void CodeExtractor::findInputsOutputs(Values &inputs, Values &outputs) {
194 std::set<BasicBlock*> ExitBlocks;
195 for (std::set<BasicBlock*>::const_iterator ci = BlocksToExtract.begin(),
196 ce = BlocksToExtract.end(); ci != ce; ++ci) {
197 BasicBlock *BB = *ci;
199 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
200 // If a used value is defined outside the region, it's an input. If an
201 // instruction is used outside the region, it's an output.
202 for (User::op_iterator O = I->op_begin(), E = I->op_end(); O != E; ++O)
203 if (definedInCaller(*O))
204 inputs.push_back(*O);
206 // Consider uses of this instruction (outputs).
207 for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
209 if (!definedInRegion(*UI)) {
210 outputs.push_back(I);
215 // Keep track of the exit blocks from the region.
216 TerminatorInst *TI = BB->getTerminator();
217 for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
218 if (!BlocksToExtract.count(TI->getSuccessor(i)))
219 ExitBlocks.insert(TI->getSuccessor(i));
220 } // for: basic blocks
222 NumExitBlocks = ExitBlocks.size();
225 /// constructFunction - make a function based on inputs and outputs, as follows:
226 /// f(in0, ..., inN, out0, ..., outN)
228 Function *CodeExtractor::constructFunction(const Values &inputs,
229 const Values &outputs,
231 BasicBlock *newRootNode,
232 BasicBlock *newHeader,
233 Function *oldFunction,
235 DEBUG(std::cerr << "inputs: " << inputs.size() << "\n");
236 DEBUG(std::cerr << "outputs: " << outputs.size() << "\n");
238 // This function returns unsigned, outputs will go back by reference.
239 switch (NumExitBlocks) {
241 case 1: RetTy = Type::VoidTy; break;
242 case 2: RetTy = Type::BoolTy; break;
243 default: RetTy = Type::UShortTy; break;
246 std::vector<const Type*> paramTy;
248 // Add the types of the input values to the function's argument list
249 for (Values::const_iterator i = inputs.begin(),
250 e = inputs.end(); i != e; ++i) {
251 const Value *value = *i;
252 DEBUG(std::cerr << "value used in func: " << value << "\n");
253 paramTy.push_back(value->getType());
256 // Add the types of the output values to the function's argument list.
257 for (Values::const_iterator I = outputs.begin(), E = outputs.end();
259 DEBUG(std::cerr << "instr used in func: " << *I << "\n");
261 paramTy.push_back((*I)->getType());
263 paramTy.push_back(PointerType::get((*I)->getType()));
266 DEBUG(std::cerr << "Function type: " << RetTy << " f(");
267 DEBUG(for (std::vector<const Type*>::iterator i = paramTy.begin(),
268 e = paramTy.end(); i != e; ++i) std::cerr << *i << ", ");
269 DEBUG(std::cerr << ")\n");
271 if (AggregateArgs && (inputs.size() + outputs.size() > 0)) {
272 PointerType *StructPtr = PointerType::get(StructType::get(paramTy));
274 paramTy.push_back(StructPtr);
276 const FunctionType *funcType = FunctionType::get(RetTy, paramTy, false);
278 // Create the new function
279 Function *newFunction = new Function(funcType,
280 GlobalValue::InternalLinkage,
281 oldFunction->getName() + "_code", M);
282 newFunction->getBasicBlockList().push_back(newRootNode);
284 // Create an iterator to name all of the arguments we inserted.
285 Function::aiterator AI = newFunction->abegin();
287 // Rewrite all users of the inputs in the extracted region to use the
288 // arguments (or appropriate addressing into struct) instead.
289 for (unsigned i = 0, e = inputs.size(); i != e; ++i) {
292 std::vector<Value*> Indices;
293 Indices.push_back(Constant::getNullValue(Type::UIntTy));
294 Indices.push_back(ConstantUInt::get(Type::UIntTy, i));
295 std::string GEPname = "gep_" + inputs[i]->getName();
296 TerminatorInst *TI = newFunction->begin()->getTerminator();
297 GetElementPtrInst *GEP = new GetElementPtrInst(AI, Indices, GEPname, TI);
298 RewriteVal = new LoadInst(GEP, "load" + GEPname, TI);
302 std::vector<User*> Users(inputs[i]->use_begin(), inputs[i]->use_end());
303 for (std::vector<User*>::iterator use = Users.begin(), useE = Users.end();
305 if (Instruction* inst = dyn_cast<Instruction>(*use))
306 if (BlocksToExtract.count(inst->getParent()))
307 inst->replaceUsesOfWith(inputs[i], RewriteVal);
310 // Set names for input and output arguments.
311 if (!AggregateArgs) {
312 AI = newFunction->abegin();
313 for (unsigned i = 0, e = inputs.size(); i != e; ++i, ++AI)
314 AI->setName(inputs[i]->getName());
315 for (unsigned i = 0, e = outputs.size(); i != e; ++i, ++AI)
316 AI->setName(outputs[i]->getName()+".out");
319 // Rewrite branches to basic blocks outside of the loop to new dummy blocks
320 // within the new function. This must be done before we lose track of which
321 // blocks were originally in the code region.
322 std::vector<User*> Users(header->use_begin(), header->use_end());
323 for (unsigned i = 0, e = Users.size(); i != e; ++i)
324 // The BasicBlock which contains the branch is not in the region
325 // modify the branch target to a new block
326 if (TerminatorInst *TI = dyn_cast<TerminatorInst>(Users[i]))
327 if (!BlocksToExtract.count(TI->getParent()) &&
328 TI->getParent()->getParent() == oldFunction)
329 TI->replaceUsesOfWith(header, newHeader);
334 /// emitCallAndSwitchStatement - This method sets up the caller side by adding
335 /// the call instruction, splitting any PHI nodes in the header block as
338 emitCallAndSwitchStatement(Function *newFunction, BasicBlock *codeReplacer,
339 Values &inputs, Values &outputs) {
340 // Emit a call to the new function, passing in: *pointer to struct (if
341 // aggregating parameters), or plan inputs and allocated memory for outputs
342 std::vector<Value*> params, StructValues, ReloadOutputs;
344 // Add inputs as params, or to be filled into the struct
345 for (Values::iterator i = inputs.begin(), e = inputs.end(); i != e; ++i)
347 StructValues.push_back(*i);
349 params.push_back(*i);
351 // Create allocas for the outputs
352 for (Values::iterator i = outputs.begin(), e = outputs.end(); i != e; ++i) {
354 StructValues.push_back(*i);
357 new AllocaInst((*i)->getType(), 0, (*i)->getName()+".loc",
358 codeReplacer->getParent()->begin()->begin());
359 ReloadOutputs.push_back(alloca);
360 params.push_back(alloca);
364 AllocaInst *Struct = 0;
365 if (AggregateArgs && (inputs.size() + outputs.size() > 0)) {
366 std::vector<const Type*> ArgTypes;
367 for (Values::iterator v = StructValues.begin(),
368 ve = StructValues.end(); v != ve; ++v)
369 ArgTypes.push_back((*v)->getType());
371 // Allocate a struct at the beginning of this function
372 Type *StructArgTy = StructType::get(ArgTypes);
374 new AllocaInst(StructArgTy, 0, "structArg",
375 codeReplacer->getParent()->begin()->begin());
376 params.push_back(Struct);
378 for (unsigned i = 0, e = inputs.size(); i != e; ++i) {
379 std::vector<Value*> Indices;
380 Indices.push_back(Constant::getNullValue(Type::UIntTy));
381 Indices.push_back(ConstantUInt::get(Type::UIntTy, i));
382 GetElementPtrInst *GEP =
383 new GetElementPtrInst(Struct, Indices,
384 "gep_" + StructValues[i]->getName(), 0);
385 codeReplacer->getInstList().push_back(GEP);
386 StoreInst *SI = new StoreInst(StructValues[i], GEP);
387 codeReplacer->getInstList().push_back(SI);
391 // Emit the call to the function
392 CallInst *call = new CallInst(newFunction, params,
393 NumExitBlocks > 1 ? "targetBlock": "");
394 codeReplacer->getInstList().push_back(call);
396 Function::aiterator OutputArgBegin = newFunction->abegin();
397 unsigned FirstOut = inputs.size();
399 std::advance(OutputArgBegin, inputs.size());
401 // Reload the outputs passed in by reference
402 for (unsigned i = 0, e = outputs.size(); i != e; ++i) {
405 std::vector<Value*> Indices;
406 Indices.push_back(Constant::getNullValue(Type::UIntTy));
407 Indices.push_back(ConstantUInt::get(Type::UIntTy, FirstOut + i));
408 GetElementPtrInst *GEP
409 = new GetElementPtrInst(Struct, Indices,
410 "gep_reload_" + outputs[i]->getName(), 0);
411 codeReplacer->getInstList().push_back(GEP);
414 Output = ReloadOutputs[i];
416 LoadInst *load = new LoadInst(Output, outputs[i]->getName()+".reload");
417 codeReplacer->getInstList().push_back(load);
418 std::vector<User*> Users(outputs[i]->use_begin(), outputs[i]->use_end());
419 for (unsigned u = 0, e = Users.size(); u != e; ++u) {
420 Instruction *inst = cast<Instruction>(Users[u]);
421 if (!BlocksToExtract.count(inst->getParent()))
422 inst->replaceUsesOfWith(outputs[i], load);
426 // Now we can emit a switch statement using the call as a value.
427 SwitchInst *TheSwitch =
428 new SwitchInst(ConstantUInt::getNullValue(Type::UShortTy),
429 codeReplacer, codeReplacer);
431 // Since there may be multiple exits from the original region, make the new
432 // function return an unsigned, switch on that number. This loop iterates
433 // over all of the blocks in the extracted region, updating any terminator
434 // instructions in the to-be-extracted region that branch to blocks that are
435 // not in the region to be extracted.
436 std::map<BasicBlock*, BasicBlock*> ExitBlockMap;
438 unsigned switchVal = 0;
439 for (std::set<BasicBlock*>::const_iterator i = BlocksToExtract.begin(),
440 e = BlocksToExtract.end(); i != e; ++i) {
441 TerminatorInst *TI = (*i)->getTerminator();
442 for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
443 if (!BlocksToExtract.count(TI->getSuccessor(i))) {
444 BasicBlock *OldTarget = TI->getSuccessor(i);
445 // add a new basic block which returns the appropriate value
446 BasicBlock *&NewTarget = ExitBlockMap[OldTarget];
448 // If we don't already have an exit stub for this non-extracted
449 // destination, create one now!
450 NewTarget = new BasicBlock(OldTarget->getName() + ".exitStub",
452 unsigned SuccNum = switchVal++;
455 switch (NumExitBlocks) {
457 case 1: break; // No value needed.
458 case 2: // Conditional branch, return a bool
459 brVal = SuccNum ? ConstantBool::False : ConstantBool::True;
462 brVal = ConstantUInt::get(Type::UShortTy, SuccNum);
466 ReturnInst *NTRet = new ReturnInst(brVal, NewTarget);
468 // Update the switch instruction.
469 TheSwitch->addCase(ConstantUInt::get(Type::UShortTy, SuccNum),
472 // Restore values just before we exit
473 Function::aiterator OAI = OutputArgBegin;
474 for (unsigned out = 0, e = outputs.size(); out != e; ++out) {
475 // For an invoke, the normal destination is the only one that is
476 // dominated by the result of the invocation
477 BasicBlock *DefBlock = cast<Instruction>(outputs[out])->getParent();
478 if (InvokeInst *Invoke = dyn_cast<InvokeInst>(outputs[out]))
479 DefBlock = Invoke->getNormalDest();
480 if (!DS || DS->dominates(DefBlock, TI->getParent()))
482 std::vector<Value*> Indices;
483 Indices.push_back(Constant::getNullValue(Type::UIntTy));
484 Indices.push_back(ConstantUInt::get(Type::UIntTy,FirstOut+out));
485 GetElementPtrInst *GEP =
486 new GetElementPtrInst(OAI, Indices,
487 "gep_" + outputs[out]->getName(),
489 new StoreInst(outputs[out], GEP, NTRet);
491 new StoreInst(outputs[out], OAI, NTRet);
492 // Advance output iterator even if we don't emit a store
493 if (!AggregateArgs) ++OAI;
497 // rewrite the original branch instruction with this new target
498 TI->setSuccessor(i, NewTarget);
502 // Now that we've done the deed, simplify the switch instruction.
503 switch (NumExitBlocks) {
505 // There is only 1 successor (the block containing the switch itself), which
506 // means that previously this was the last part of the function, and hence
507 // this should be rewritten as a `ret'
509 // Check if the function should return a value
510 if (TheSwitch->getParent()->getParent()->getReturnType() != Type::VoidTy &&
511 TheSwitch->getParent()->getParent()->getReturnType() ==
512 TheSwitch->getCondition()->getType())
513 // return what we have
514 new ReturnInst(TheSwitch->getCondition(), TheSwitch);
517 new ReturnInst(0, TheSwitch);
519 TheSwitch->getParent()->getInstList().erase(TheSwitch);
522 // Only a single destination, change the switch into an unconditional
524 new BranchInst(TheSwitch->getSuccessor(1), TheSwitch);
525 TheSwitch->getParent()->getInstList().erase(TheSwitch);
528 new BranchInst(TheSwitch->getSuccessor(1), TheSwitch->getSuccessor(2),
530 TheSwitch->getParent()->getInstList().erase(TheSwitch);
533 // Otherwise, make the default destination of the switch instruction be one
534 // of the other successors.
535 TheSwitch->setOperand(0, call);
536 TheSwitch->setSuccessor(0, TheSwitch->getSuccessor(NumExitBlocks));
537 TheSwitch->removeCase(NumExitBlocks); // Remove redundant case
542 void CodeExtractor::moveCodeToFunction(Function *newFunction) {
543 Function *oldFunc = (*BlocksToExtract.begin())->getParent();
544 Function::BasicBlockListType &oldBlocks = oldFunc->getBasicBlockList();
545 Function::BasicBlockListType &newBlocks = newFunction->getBasicBlockList();
547 for (std::set<BasicBlock*>::const_iterator i = BlocksToExtract.begin(),
548 e = BlocksToExtract.end(); i != e; ++i) {
549 // Delete the basic block from the old function, and the list of blocks
550 oldBlocks.remove(*i);
552 // Insert this basic block into the new function
553 newBlocks.push_back(*i);
557 /// ExtractRegion - Removes a loop from a function, replaces it with a call to
558 /// new function. Returns pointer to the new function.
562 /// find inputs and outputs for the region
564 /// for inputs: add to function as args, map input instr* to arg#
565 /// for outputs: add allocas for scalars,
566 /// add to func as args, map output instr* to arg#
568 /// rewrite func to use argument #s instead of instr*
570 /// for each scalar output in the function: at every exit, store intermediate
571 /// computed result back into memory.
573 Function *CodeExtractor::ExtractCodeRegion(const std::vector<BasicBlock*> &code)
575 if (!isEligible(code))
578 // 1) Find inputs, outputs
579 // 2) Construct new function
580 // * Add allocas for defs, pass as args by reference
581 // * Pass in uses as args
582 // 3) Move code region, add call instr to func
584 BlocksToExtract.insert(code.begin(), code.end());
586 Values inputs, outputs;
588 // Assumption: this is a single-entry code region, and the header is the first
589 // block in the region.
590 BasicBlock *header = code[0];
592 for (unsigned i = 1, e = code.size(); i != e; ++i)
593 for (pred_iterator PI = pred_begin(code[i]), E = pred_end(code[i]);
595 assert(BlocksToExtract.count(*PI) &&
596 "No blocks in this region may have entries from outside the region"
597 " except for the first block!");
599 // If we have to split PHI nodes, do so now.
600 severSplitPHINodes(header);
602 Function *oldFunction = header->getParent();
604 // This takes place of the original loop
605 BasicBlock *codeReplacer = new BasicBlock("codeRepl", oldFunction);
607 // The new function needs a root node because other nodes can branch to the
608 // head of the region, but the entry node of a function cannot have preds.
609 BasicBlock *newFuncRoot = new BasicBlock("newFuncRoot");
610 newFuncRoot->getInstList().push_back(new BranchInst(header));
612 // Find inputs to, outputs from the code region.
613 findInputsOutputs(inputs, outputs);
615 // Construct new function based on inputs/outputs & add allocas for all defs.
616 Function *newFunction = constructFunction(inputs, outputs, header,
618 codeReplacer, oldFunction,
619 oldFunction->getParent());
621 emitCallAndSwitchStatement(newFunction, codeReplacer, inputs, outputs);
623 moveCodeToFunction(newFunction);
625 // Loop over all of the PHI nodes in the header block, and change any
626 // references to the old incoming edge to be the new incoming edge.
627 for (BasicBlock::iterator I = header->begin();
628 PHINode *PN = dyn_cast<PHINode>(I); ++I)
629 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
630 if (!BlocksToExtract.count(PN->getIncomingBlock(i)))
631 PN->setIncomingBlock(i, newFuncRoot);
633 // Look at all successors of the codeReplacer block. If any of these blocks
634 // had PHI nodes in them, we need to update the "from" block to be the code
635 // replacer, not the original block in the extracted region.
636 std::vector<BasicBlock*> Succs(succ_begin(codeReplacer),
637 succ_end(codeReplacer));
638 for (unsigned i = 0, e = Succs.size(); i != e; ++i)
639 for (BasicBlock::iterator I = Succs[i]->begin();
640 PHINode *PN = dyn_cast<PHINode>(I); ++I)
641 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
642 if (BlocksToExtract.count(PN->getIncomingBlock(i)))
643 PN->setIncomingBlock(i, codeReplacer);
645 //std::cerr << "NEW FUNCTION: " << *newFunction;
646 // verifyFunction(*newFunction);
648 // std::cerr << "OLD FUNCTION: " << *oldFunction;
649 // verifyFunction(*oldFunction);
651 DEBUG(if (verifyFunction(*newFunction)) abort());
655 bool CodeExtractor::isEligible(const std::vector<BasicBlock*> &code) {
656 // Deny code region if it contains allocas or vastarts.
657 for (std::vector<BasicBlock*>::const_iterator BB = code.begin(), e=code.end();
659 for (BasicBlock::const_iterator I = (*BB)->begin(), Ie = (*BB)->end();
661 if (isa<AllocaInst>(*I))
663 else if (const CallInst *CI = dyn_cast<CallInst>(I))
664 if (const Function *F = CI->getCalledFunction())
665 if (F->getIntrinsicID() == Intrinsic::vastart)
671 /// ExtractCodeRegion - slurp a sequence of basic blocks into a brand new
674 Function* llvm::ExtractCodeRegion(DominatorSet &DS,
675 const std::vector<BasicBlock*> &code,
676 bool AggregateArgs) {
677 return CodeExtractor(&DS, AggregateArgs).ExtractCodeRegion(code);
680 /// ExtractBasicBlock - slurp a natural loop into a brand new function
682 Function* llvm::ExtractLoop(DominatorSet &DS, Loop *L, bool AggregateArgs) {
683 return CodeExtractor(&DS, AggregateArgs).ExtractCodeRegion(L->getBlocks());
686 /// ExtractBasicBlock - slurp a basic block into a brand new function
688 Function* llvm::ExtractBasicBlock(BasicBlock *BB, bool AggregateArgs) {
689 std::vector<BasicBlock*> Blocks;
690 Blocks.push_back(BB);
691 return CodeExtractor(0, AggregateArgs).ExtractCodeRegion(Blocks);