/// isLCSSAForm - Return true if the Loop is in LCSSA form
bool Loop::isLCSSAForm(DominatorTree &DT) const {
// Sort the blocks vector so that we can use binary search to do quick
// lookups.
SmallPtrSet<BasicBlock*, 16> LoopBBs(block_begin(), block_end());
for (block_iterator BI = block_begin(), E = block_end(); BI != E; ++BI) {
BasicBlock *BB = *BI;
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;++I)
for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
++UI) {
User *U = *UI;
BasicBlock *UserBB = cast<Instruction>(U)->getParent();
if (PHINode *P = dyn_cast<PHINode>(U))
UserBB = P->getIncomingBlock(UI);
// Check the current block, as a fast-path, before checking whether
// the use is anywhere in the loop. Most values are used in the same
// block they are defined in. Also, blocks not reachable from the
// entry are special; uses in them don't need to go through PHIs.
if (UserBB != BB &&
!LoopBBs.count(UserBB) &&
DT.isReachableFromEntry(UserBB))
return false;
}
}
return true;
}
/// Handle a rare case where the disintegrated nodes instructions
/// no longer dominate all their uses. Not sure if this is really nessasary
void StructurizeCFG::rebuildSSA() {
SSAUpdater Updater;
for (const auto &BB : ParentRegion->blocks())
for (BasicBlock::iterator II = BB->begin(), IE = BB->end();
II != IE; ++II) {
bool Initialized = false;
for (auto I = II->use_begin(), E = II->use_end(); I != E;) {
Use &U = *I++;
Instruction *User = cast<Instruction>(U.getUser());
if (User->getParent() == BB) {
continue;
} else if (PHINode *UserPN = dyn_cast<PHINode>(User)) {
if (UserPN->getIncomingBlock(U) == BB)
continue;
}
if (DT->dominates(II, User))
continue;
if (!Initialized) {
Value *Undef = UndefValue::get(II->getType());
Updater.Initialize(II->getType(), "");
Updater.AddAvailableValue(&Func->getEntryBlock(), Undef);
Updater.AddAvailableValue(BB, II);
Initialized = true;
}
Updater.RewriteUseAfterInsertions(U);
}
}
}
/// If there's a single exit block, sink any loop-invariant values that
/// were defined in the preheader but not used inside the loop into the
/// exit block to reduce register pressure in the loop.
void IndVarSimplify::SinkUnusedInvariants(Loop *L) {
BasicBlock *ExitBlock = L->getExitBlock();
if (!ExitBlock) return;
BasicBlock *Preheader = L->getLoopPreheader();
if (!Preheader) return;
Instruction *InsertPt = ExitBlock->getFirstNonPHI();
BasicBlock::iterator I = Preheader->getTerminator();
while (I != Preheader->begin()) {
--I;
// New instructions were inserted at the end of the preheader.
if (isa<PHINode>(I))
break;
// Don't move instructions which might have side effects, since the side
// effects need to complete before instructions inside the loop. Also
// don't move instructions which might read memory, since the loop may
// modify memory. Note that it's okay if the instruction might have
// undefined behavior: LoopSimplify guarantees that the preheader
// dominates the exit block.
if (I->mayHaveSideEffects() || I->mayReadFromMemory())
continue;
// Don't sink static AllocaInsts out of the entry block, which would
// turn them into dynamic allocas!
if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
if (AI->isStaticAlloca())
continue;
// Determine if there is a use in or before the loop (direct or
// otherwise).
bool UsedInLoop = false;
for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
UI != UE; ++UI) {
BasicBlock *UseBB = cast<Instruction>(UI)->getParent();
if (PHINode *P = dyn_cast<PHINode>(UI)) {
unsigned i =
PHINode::getIncomingValueNumForOperand(UI.getOperandNo());
UseBB = P->getIncomingBlock(i);
}
if (UseBB == Preheader || L->contains(UseBB)) {
UsedInLoop = true;
break;
}
}
// If there is, the def must remain in the preheader.
if (UsedInLoop)
continue;
// Otherwise, sink it to the exit block.
Instruction *ToMove = I;
bool Done = false;
if (I != Preheader->begin())
--I;
else
Done = true;
ToMove->moveBefore(InsertPt);
if (Done)
break;
InsertPt = ToMove;
}
}
bool RemoveExtendsPass::runOnFunction(Function& f)
{
CurrentFile::set(__FILE__);
bool changed = false ;
//see if there are any ROCCCNames or ROCCCSizes that caused the extend
for(Function::iterator BB = f.begin(); BB != f.end(); ++BB)
{
begin:
for(BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II)
{
if( dynamic_cast<FPExtInst*>(&*II) or
dynamic_cast<ZExtInst*>(&*II) or
dynamic_cast<SExtInst*>(&*II) or
dynamic_cast<BitCastInst*>(&*II) )
{
INTERNAL_MESSAGE("Attempting to remove uses of " << II->getName() << "\n");
for(Value::use_iterator UI = II->use_begin(); UI != II->use_end(); ++UI)
{
dynamic_cast<Instruction*>(*UI)->replaceUsesOfWith(II, II->getOperand(0));
goto begin;
}
if( II->use_begin() == II->use_end() )
{
II->eraseFromParent();
II = BB->begin();
}
else
{
INTERNAL_ERROR("Extend " << *II << " is still used in " << **II->use_begin() << "!");
assert(0 and "Extend operation still exists!");
}
}
}
}
return changed ;
}
/// isLCSSAForm - Return true if the Loop is in LCSSA form
bool Loop::isLCSSAForm() const {
// Sort the blocks vector so that we can use binary search to do quick
// lookups.
SmallPtrSet<BasicBlock *, 16> LoopBBs(block_begin(), block_end());
for (block_iterator BI = block_begin(), E = block_end(); BI != E; ++BI) {
BasicBlock *BB = *BI;
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;++I)
for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
++UI) {
BasicBlock *UserBB = cast<Instruction>(*UI)->getParent();
if (PHINode *P = dyn_cast<PHINode>(*UI))
UserBB = P->getIncomingBlock(UI);
// Check the current block, as a fast-path. Most values are used in
// the same block they are defined in.
if (UserBB != BB && !LoopBBs.count(UserBB))
return false;
}
}
return true;
}
bool UnregisteredFanoutAnalysisPass::runOnFunction(Function& f)
{
CurrentFile::set(__FILE__);
bool changed = false ;
if (f.isDeclaration() || f.getDFFunction() == NULL)
{
return changed ;
}
unsigned int MAX_FANOUT = 50;
std::ifstream file(".ROCCC/.timingInfo");
if (!file)
{
INTERNAL_SERIOUS_WARNING("Could not open timing information file for max fanout!\n");
}
else
{
while( !file.eof() )
{
std::string name;
int value = -1;
file >> name;
//allow comments
if( name.find("#") == 0 or name.find("//") == 0 or name.find("--") == 0 )
{
std::string temp;
std::getline(file, temp);
}
else
{
file >> value;
}
if( name == "MaxFanoutRegistered" and value >= 0 )
{
MAX_FANOUT = value;
}
}
}
LOG_MESSAGE2("Pipelining", "Fanout Analysis", "In order to reduce the negative effect on frequency that a high unregistered fanout can have, operations with a fanout greater than " << MAX_FANOUT << " will be registered.\n");
std::map<DFBasicBlock*, bool> allBlocks = getPipelineBlocks(f);
for(std::map<DFBasicBlock*,bool>::iterator BBI = allBlocks.begin(); BBI != allBlocks.end(); ++BBI)
{
if( BBI->second )
{
for( BasicBlock::iterator II = BBI->first->begin(); II != BBI->first->end(); ++II )
{
unsigned int realFanout = 0;
for(Instruction::use_iterator UI = II->use_begin(); UI != II->use_end(); ++UI)
{
if( dynamic_cast<Instruction*>(*UI) and
allBlocks.find(dynamic_cast<Instruction*>(*UI)->getParent()->getDFBasicBlock()) != allBlocks.end() and
allBlocks.find(dynamic_cast<Instruction*>(*UI)->getParent()->getDFBasicBlock())->second != false and
!isDefinition(dynamic_cast<Instruction*>(*UI), II) )
{
++realFanout;
}
}
if( realFanout > MAX_FANOUT )
{
LOG_MESSAGE2("Pipelining", "Fanout Analysis", getValueName(II) << " has fanout of " << realFanout << "; "
"Putting " << getValueName(II) << " into own pipeline stage.\n");
Pipelining::TimingRequirements* timing = Pipelining::TimingRequirements::getCurrentRequirements(&f);
timing->setBasicBlockDelay(BBI->first, timing->getDesiredDelay());
}
}
}
}
return changed ;
}
void DSWP::buildPDG(Loop *L) {
//Initialize PDG
for (Loop::block_iterator bi = L->getBlocks().begin(); bi != L->getBlocks().end(); bi++) {
BasicBlock *BB = *bi;
for (BasicBlock::iterator ui = BB->begin(); ui != BB->end(); ui++) {
Instruction *inst = &(*ui);
//standardlize the name for all expr
if (util.hasNewDef(inst)) {
inst->setName(util.genId());
dname[inst] = inst->getNameStr();
} else {
dname[inst] = util.genId();
}
pdg[inst] = new vector<Edge>();
rev[inst] = new vector<Edge>();
}
}
//LoopInfo &li = getAnalysis<LoopInfo>();
/*
* Memory dependency analysis
*/
MemoryDependenceAnalysis &mda = getAnalysis<MemoryDependenceAnalysis>();
for (Loop::block_iterator bi = L->getBlocks().begin(); bi != L->getBlocks().end(); bi++) {
BasicBlock *BB = *bi;
for (BasicBlock::iterator ii = BB->begin(); ii != BB->end(); ii++) {
Instruction *inst = &(*ii);
//data dependence = register dependence + memory dependence
//begin register dependence
for (Value::use_iterator ui = ii->use_begin(); ui != ii->use_end(); ui++) {
if (Instruction *user = dyn_cast<Instruction>(*ui)) {
addEdge(inst, user, REG);
}
}
//finish register dependence
//begin memory dependence
MemDepResult mdr = mda.getDependency(inst);
//TODO not sure clobbers mean!!
if (mdr.isDef()) {
Instruction *dep = mdr.getInst();
if (isa<LoadInst>(inst)) {
if (isa<StoreInst>(dep)) {
addEdge(dep, inst, DTRUE); //READ AFTER WRITE
}
}
if (isa<StoreInst>(inst)) {
if (isa<LoadInst>(dep)) {
addEdge(dep, inst, DANTI); //WRITE AFTER READ
}
if (isa<StoreInst>(dep)) {
addEdge(dep, inst, DOUT); //WRITE AFTER WRITE
}
}
//READ AFTER READ IS INSERT AFTER PDG BUILD
}
//end memory dependence
}//for ii
}//for bi
/*
* begin control dependence
*/
PostDominatorTree &pdt = getAnalysis<PostDominatorTree>();
//cout << pdt.getRootNode()->getBlock()->getNameStr() << endl;
/*
* alien code part 1
*/
LoopInfo *LI = &getAnalysis<LoopInfo>();
std::set<BranchInst*> backedgeParents;
for (Loop::block_iterator bi = L->getBlocks().begin(); bi
!= L->getBlocks().end(); bi++) {
BasicBlock *BB = *bi;
for (BasicBlock::iterator ii = BB->begin(); ii != BB->end(); ii++) {
Instruction *inst = ii;
if (BranchInst *brInst = dyn_cast<BranchInst>(inst)) {
// get the loop this instruction (and therefore basic block) belongs to
Loop *instLoop = LI->getLoopFor(BB);
bool branchesToHeader = false;
for (int i = brInst->getNumSuccessors() - 1; i >= 0
&& !branchesToHeader; i--) {
// if the branch could exit, store it
if (LI->getLoopFor(brInst->getSuccessor(i)) != instLoop) {
branchesToHeader = true;
}
}
if (branchesToHeader) {
backedgeParents.insert(brInst);
}
}
}
}
//build information for predecessor of blocks in post dominator tree
for (Function::iterator bi = func->begin(); bi != func->end(); bi++) {
BasicBlock *BB = bi;
DomTreeNode *dn = pdt.getNode(BB);
for (DomTreeNode::iterator di = dn->begin(); di != dn->end(); di++) {
BasicBlock *CB = (*di)->getBlock();
pre[CB] = BB;
}
}
//
// //add dependency within a basicblock
// for (Loop::block_iterator bi = L->getBlocks().begin(); bi != L->getBlocks().end(); bi++) {
// BasicBlock *BB = *bi;
// Instruction *pre = NULL;
// for (BasicBlock::iterator ui = BB->begin(); ui != BB->end(); ui++) {
// Instruction *inst = &(*ui);
// if (pre != NULL) {
// addEdge(pre, inst, CONTROL);
// }
// pre = inst;
// }
// }
// //the special kind of dependence need loop peeling ? I don't know whether this is needed
// for (Loop::block_iterator bi = L->getBlocks().begin(); bi != L->getBlocks().end(); bi++) {
// BasicBlock *BB = *bi;
// for (succ_iterator PI = succ_begin(BB); PI != succ_end(BB); ++PI) {
// BasicBlock *succ = *PI;
//
// checkControlDependence(BB, succ, pdt);
// }
// }
/*
* alien code part 2
*/
// add normal control dependencies
// loop through each instruction
for (Loop::block_iterator bbIter = L->block_begin(); bbIter
!= L->block_end(); ++bbIter) {
BasicBlock *bb = *bbIter;
// check the successors of this basic block
if (BranchInst *branchInst = dyn_cast<BranchInst>(bb->getTerminator())) {
if (branchInst->getNumSuccessors() > 1) {
BasicBlock * succ = branchInst->getSuccessor(0);
// if the successor is nested shallower than the current basic block, continue
if (LI->getLoopDepth(bb) < LI->getLoopDepth(succ)) {
continue;
}
// otherwise, add all instructions to graph as control dependence
while (succ != NULL && succ != bb && LI->getLoopDepth(succ)
>= LI->getLoopDepth(bb)) {
Instruction *terminator = bb->getTerminator();
for (BasicBlock::iterator succInstIter = succ->begin(); &(*succInstIter)
!= succ->getTerminator(); ++succInstIter) {
addEdge(terminator, &(*succInstIter), CONTROL);
}
if (BranchInst *succBrInst = dyn_cast<BranchInst>(succ->getTerminator())) {
if (succBrInst->getNumSuccessors() > 1) {
addEdge(terminator, succ->getTerminator(),
CONTROL);
}
}
if (BranchInst *br = dyn_cast<BranchInst>(succ->getTerminator())) {
if (br->getNumSuccessors() == 1) {
succ = br->getSuccessor(0);
} else {
succ = NULL;
}
} else {
succ = NULL;
}
}
}
}
}
/*
* alien code part 3
*/
for (std::set<BranchInst*>::iterator exitIter = backedgeParents.begin(); exitIter != backedgeParents.end(); ++exitIter) {
BranchInst *exitBranch = *exitIter;
if (exitBranch->isConditional()) {
BasicBlock *header = LI->getLoopFor(exitBranch->getParent())->getHeader();
for (BasicBlock::iterator ctrlIter = header->begin(); ctrlIter != header->end(); ++ctrlIter) {
addEdge(exitBranch, &(*ctrlIter), CONTROL);
}
}
}
//end control dependence
}
bool LoopUnroll::visitLoop(Loop *L) {
bool Changed = false;
// Recurse through all subloops before we process this loop. Copy the loop
// list so that the child can update the loop tree if it needs to delete the
// loop.
std::vector<Loop*> SubLoops(L->begin(), L->end());
for (unsigned i = 0, e = SubLoops.size(); i != e; ++i)
Changed |= visitLoop(SubLoops[i]);
// We only handle single basic block loops right now.
if (L->getBlocks().size() != 1)
return Changed;
BasicBlock *BB = L->getHeader();
BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator());
if (BI == 0) return Changed; // Must end in a conditional branch
ConstantInt *TripCountC = dyn_cast_or_null<ConstantInt>(L->getTripCount());
if (!TripCountC) return Changed; // Must have constant trip count!
unsigned TripCount = TripCountC->getRawValue();
if (TripCount != TripCountC->getRawValue() || TripCount == 0)
return Changed; // More than 2^32 iterations???
unsigned LoopSize = ApproximateLoopSize(L);
DEBUG(std::cerr << "Loop Unroll: F[" << BB->getParent()->getName()
<< "] Loop %" << BB->getName() << " Loop Size = " << LoopSize
<< " Trip Count = " << TripCount << " - ");
uint64_t Size = (uint64_t)LoopSize*(uint64_t)TripCount;
if (Size > UnrollThreshold) {
DEBUG(std::cerr << "TOO LARGE: " << Size << ">" << UnrollThreshold << "\n");
return Changed;
}
DEBUG(std::cerr << "UNROLLING!\n");
BasicBlock *LoopExit = BI->getSuccessor(L->contains(BI->getSuccessor(0)));
// Create a new basic block to temporarily hold all of the cloned code.
BasicBlock *NewBlock = new BasicBlock();
// For the first iteration of the loop, we should use the precloned values for
// PHI nodes. Insert associations now.
std::map<const Value*, Value*> LastValueMap;
std::vector<PHINode*> OrigPHINode;
for (BasicBlock::iterator I = BB->begin();
PHINode *PN = dyn_cast<PHINode>(I); ++I) {
OrigPHINode.push_back(PN);
if (Instruction *I =dyn_cast<Instruction>(PN->getIncomingValueForBlock(BB)))
if (I->getParent() == BB)
LastValueMap[I] = I;
}
// Remove the exit branch from the loop
BB->getInstList().erase(BI);
assert(TripCount != 0 && "Trip count of 0 is impossible!");
for (unsigned It = 1; It != TripCount; ++It) {
char SuffixBuffer[100];
sprintf(SuffixBuffer, ".%d", It);
std::map<const Value*, Value*> ValueMap;
BasicBlock *New = CloneBasicBlock(BB, ValueMap, SuffixBuffer);
// Loop over all of the PHI nodes in the block, changing them to use the
// incoming values from the previous block.
for (unsigned i = 0, e = OrigPHINode.size(); i != e; ++i) {
PHINode *NewPHI = cast<PHINode>(ValueMap[OrigPHINode[i]]);
Value *InVal = NewPHI->getIncomingValueForBlock(BB);
if (Instruction *InValI = dyn_cast<Instruction>(InVal))
if (InValI->getParent() == BB)
InVal = LastValueMap[InValI];
ValueMap[OrigPHINode[i]] = InVal;
New->getInstList().erase(NewPHI);
}
for (BasicBlock::iterator I = New->begin(), E = New->end(); I != E; ++I)
RemapInstruction(I, ValueMap);
// Now that all of the instructions are remapped, splice them into the end
// of the NewBlock.
NewBlock->getInstList().splice(NewBlock->end(), New->getInstList());
delete New;
// LastValue map now contains values from this iteration.
std::swap(LastValueMap, ValueMap);
}
// If there was more than one iteration, replace any uses of values computed
// in the loop with values computed during the last iteration of the loop.
if (TripCount != 1) {
std::set<User*> Users;
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
Users.insert(I->use_begin(), I->use_end());
// We don't want to reprocess entries with PHI nodes in them. For this
// reason, we look at each operand of each user exactly once, performing the
// stubstitution exactly once.
for (std::set<User*>::iterator UI = Users.begin(), E = Users.end(); UI != E;
++UI) {
Instruction *I = cast<Instruction>(*UI);
if (I->getParent() != BB && I->getParent() != NewBlock)
RemapInstruction(I, LastValueMap);
}
}
// Now that we cloned the block as many times as we needed, stitch the new
// code into the original block and delete the temporary block.
BB->getInstList().splice(BB->end(), NewBlock->getInstList());
delete NewBlock;
// Now loop over the PHI nodes in the original block, setting them to their
// incoming values.
BasicBlock *Preheader = L->getLoopPreheader();
for (unsigned i = 0, e = OrigPHINode.size(); i != e; ++i) {
PHINode *PN = OrigPHINode[i];
PN->replaceAllUsesWith(PN->getIncomingValueForBlock(Preheader));
BB->getInstList().erase(PN);
}
// Finally, add an unconditional branch to the block to continue into the exit
// block.
new BranchInst(LoopExit, BB);
// At this point, the code is well formed. We now do a quick sweep over the
// inserted code, doing constant propagation and dead code elimination as we
// go.
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
Instruction *Inst = I++;
if (isInstructionTriviallyDead(Inst))
BB->getInstList().erase(Inst);
else if (Constant *C = ConstantFoldInstruction(Inst)) {
Inst->replaceAllUsesWith(C);
BB->getInstList().erase(Inst);
}
}
// Update the loop information for this loop.
Loop *Parent = L->getParentLoop();
// Move all of the basic blocks in the loop into the parent loop.
LI->changeLoopFor(BB, Parent);
// Remove the loop from the parent.
if (Parent)
delete Parent->removeChildLoop(std::find(Parent->begin(), Parent->end(),L));
else
delete LI->removeLoop(std::find(LI->begin(), LI->end(), L));
// FIXME: Should update dominator analyses
// Now that everything is up-to-date that will be, we fold the loop block into
// the preheader and exit block, updating our analyses as we go.
LoopExit->getInstList().splice(LoopExit->begin(), BB->getInstList(),
BB->getInstList().begin(),
prior(BB->getInstList().end()));
LoopExit->getInstList().splice(LoopExit->begin(), Preheader->getInstList(),
Preheader->getInstList().begin(),
prior(Preheader->getInstList().end()));
// Make all other blocks in the program branch to LoopExit now instead of
// Preheader.
Preheader->replaceAllUsesWith(LoopExit);
// Remove BB and LoopExit from our analyses.
LI->removeBlock(Preheader);
LI->removeBlock(BB);
// If the preheader was the entry block of this function, move the exit block
// to be the new entry of the loop.
Function *F = LoopExit->getParent();
if (Preheader == &F->front())
F->getBasicBlockList().splice(F->begin(), F->getBasicBlockList(), LoopExit);
// Actually delete the blocks now.
F->getBasicBlockList().erase(Preheader);
F->getBasicBlockList().erase(BB);
++NumUnrolled;
return true;
}
// TransformSetJmpCall - The setjmp call is a bit trickier to transform.
// We're going to convert all setjmp calls to nops. Then all "call" and
// "invoke" instructions in the function are converted to "invoke" where
// the "except" branch is used when returning from a longjmp call.
void LowerSetJmp::TransformSetJmpCall(CallInst* Inst)
{
BasicBlock* ABlock = Inst->getParent();
Function* Func = ABlock->getParent();
// Add this setjmp to the setjmp map.
const Type* SBPTy = PointerType::getUnqual(Type::Int8Ty);
CastInst* BufPtr =
new BitCastInst(Inst->getOperand(1), SBPTy, "SBJmpBuf", Inst);
std::vector<Value*> Args =
make_vector<Value*>(GetSetJmpMap(Func), BufPtr,
ConstantInt::get(Type::Int32Ty,
SetJmpIDMap[Func]++), 0);
CallInst::Create(AddSJToMap, Args.begin(), Args.end(), "", Inst);
// We are guaranteed that there are no values live across basic blocks
// (because we are "not in SSA form" yet), but there can still be values live
// in basic blocks. Because of this, splitting the setjmp block can cause
// values above the setjmp to not dominate uses which are after the setjmp
// call. For all of these occasions, we must spill the value to the stack.
//
std::set<Instruction*> InstrsAfterCall;
// The call is probably very close to the end of the basic block, for the
// common usage pattern of: 'if (setjmp(...))', so keep track of the
// instructions after the call.
for (BasicBlock::iterator I = ++BasicBlock::iterator(Inst), E = ABlock->end();
I != E; ++I)
InstrsAfterCall.insert(I);
for (BasicBlock::iterator II = ABlock->begin();
II != BasicBlock::iterator(Inst); ++II)
// Loop over all of the uses of instruction. If any of them are after the
// call, "spill" the value to the stack.
for (Value::use_iterator UI = II->use_begin(), E = II->use_end();
UI != E; ++UI)
if (cast<Instruction>(*UI)->getParent() != ABlock ||
InstrsAfterCall.count(cast<Instruction>(*UI))) {
DemoteRegToStack(*II);
break;
}
InstrsAfterCall.clear();
// Change the setjmp call into a branch statement. We'll remove the
// setjmp call in a little bit. No worries.
BasicBlock* SetJmpContBlock = ABlock->splitBasicBlock(Inst);
assert(SetJmpContBlock && "Couldn't split setjmp BB!!");
SetJmpContBlock->setName(ABlock->getName()+"SetJmpCont");
// Add the SetJmpContBlock to the set of blocks reachable from a setjmp.
DFSBlocks.insert(SetJmpContBlock);
// This PHI node will be in the new block created from the
// splitBasicBlock call.
PHINode* PHI = PHINode::Create(Type::Int32Ty, "SetJmpReturn", Inst);
// Coming from a call to setjmp, the return is 0.
PHI->addIncoming(ConstantInt::getNullValue(Type::Int32Ty), ABlock);
// Add the case for this setjmp's number...
SwitchValuePair SVP = GetSJSwitch(Func, GetRethrowBB(Func));
SVP.first->addCase(ConstantInt::get(Type::Int32Ty, SetJmpIDMap[Func] - 1),
SetJmpContBlock);
// Value coming from the handling of the exception.
PHI->addIncoming(SVP.second, SVP.second->getParent());
// Replace all uses of this instruction with the PHI node created by
// the eradication of setjmp.
Inst->replaceAllUsesWith(PHI);
Inst->getParent()->getInstList().erase(Inst);
++SetJmpsTransformed;
}
void RegionExtractor::findInputsOutputs(ValueSet &Inputs,
ValueSet &Outputs) const {
for (SetVector<BasicBlock *>::const_iterator I = Blocks.begin(),
E = Blocks.end();
I != E; ++I) {
BasicBlock *BB = *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 (BasicBlock::iterator II = BB->begin(), IE = BB->end();
II != IE; ++II) {
for (User::op_iterator OI = II->op_begin(), OE = II->op_end();
OI != OE; ++OI)
if (definedInCaller(Blocks, *OI))
Inputs.insert(*OI);
#if LLVM_VERSION_MINOR == 5
for (User *U : II->users())
if (!definedInRegion(Blocks, U)) {
#else
for (Value::use_iterator UI = II->use_begin(), UE = II->use_end();
UI != UE; ++UI)
if (!definedInRegion(Blocks, *UI)) {
#endif
Outputs.insert(II);
break;
}
}
}
}
/// 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 RegionExtractor::severSplitPHINodes(BasicBlock *&Header) {
unsigned NumPredsFromRegion = 0;
unsigned NumPredsOutsideRegion = 0;
if (Header != &Header->getParent()->getEntryBlock()) {
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 (Blocks.count(PN->getIncomingBlock(i)))
++NumPredsFromRegion;
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->getFirstNonPHI();
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;
Blocks.remove(OldPred);
Blocks.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 (DT)
DT->splitBlock(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 (NumPredsFromRegion) {
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 (Blocks.count(PN->getIncomingBlock(i))) {
TerminatorInst *TI = PN->getIncomingBlock(i)->getTerminator();
TI->replaceUsesOfWith(OldPred, NewBB);
}
// Okay, everything 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 = PHINode::Create(PN->getType(), 1 + NumPredsFromRegion,
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 (Blocks.count(PN->getIncomingBlock(i))) {
NewPN->addIncoming(PN->getIncomingValue(i), PN->getIncomingBlock(i));
PN->removeIncomingValue(i);
--i;
}
}
}
}
}