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[StructurizeCFG] Use range-based for loops. 

Reviewers: arsenm

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D27000

llvm-svn: 288051
This commit is contained in:
Justin Lebar 2016-11-28 18:50:03 +00:00
parent 62c20d8b3b
commit 3aec10ca7e
1 changed files with 51 additions and 72 deletions
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123
llvm/lib/Transforms/Scalar/StructurizeCFG.cpp
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@ -391,46 +391,40 @@ void StructurizeCFG::gatherPredicates(RegionNode *N) {
BBPredicates &Pred = Predicates[BB];
BBPredicates &LPred = LoopPreds[BB];
for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
PI != PE; ++PI) {
for (BasicBlock *P : predecessors(BB)) {
// Ignore it if it's a branch from outside into our region entry
if (!ParentRegion->contains(*PI))
if (!ParentRegion->contains(P))
continue;
Region *R = RI->getRegionFor(*PI);
Region *R = RI->getRegionFor(P);
if (R == ParentRegion) {
// It's a top level block in our region
BranchInst *Term = cast<BranchInst>((*PI)->getTerminator());
BranchInst *Term = cast<BranchInst>(P->getTerminator());
for (unsigned i = 0, e = Term->getNumSuccessors(); i != e; ++i) {
BasicBlock *Succ = Term->getSuccessor(i);
if (Succ != BB)
continue;
if (Visited.count(*PI)) {
if (Visited.count(P)) {
// Normal forward edge
if (Term->isConditional()) {
// Try to treat it like an ELSE block
BasicBlock *Other = Term->getSuccessor(!i);
if (Visited.count(Other) && !Loops.count(Other) &&
!Pred.count(Other) && !Pred.count(*PI)) {
!Pred.count(Other) && !Pred.count(P)) {
Pred[Other] = BoolFalse;
Pred[*PI] = BoolTrue;
Pred[P] = BoolTrue;
continue;
}
}
Pred[*PI] = buildCondition(Term, i, false);
Pred[P] = buildCondition(Term, i, false);
} else {
// Back edge
LPred[*PI] = buildCondition(Term, i, true);
LPred[P] = buildCondition(Term, i, true);
}
}
} else {
// It's an exit from a sub region
while (R->getParent() != ParentRegion)
R = R->getParent();
@ -461,7 +455,6 @@ void StructurizeCFG::collectInfos() {
Visited.clear();
for (RegionNode *RN : reverse(Order)) {
DEBUG(dbgs() << "Visiting: "
<< (RN->isSubRegion() ? "SubRegion with entry: " : "")
<< RN->getEntry()->getName() << " Loop Depth: "
@ -501,15 +494,16 @@ void StructurizeCFG::insertConditions(bool Loops) {
Dominator.addBlock(Parent);
Value *ParentValue = nullptr;
for (BBPredicates::iterator PI = Preds.begin(), PE = Preds.end();
PI != PE; ++PI) {
for (std::pair<BasicBlock *, Value *> BBAndPred : Preds) {
BasicBlock *BB = BBAndPred.first;
Value *Pred = BBAndPred.second;
if (PI->first == Parent) {
ParentValue = PI->second;
if (BB == Parent) {
ParentValue = Pred;
break;
}
PhiInserter.AddAvailableValue(PI->first, PI->second);
Dominator.addAndRememberBlock(PI->first);
PhiInserter.AddAvailableValue(BB, Pred);
Dominator.addAndRememberBlock(BB);
}
if (ParentValue) {
@ -527,10 +521,10 @@ void StructurizeCFG::insertConditions(bool Loops) {
/// them in DeletedPhis
void StructurizeCFG::delPhiValues(BasicBlock *From, BasicBlock *To) {
PhiMap &Map = DeletedPhis[To];
for (BasicBlock::iterator I = To->begin(), E = To->end();
I != E && isa<PHINode>(*I);) {
PHINode &Phi = cast<PHINode>(*I++);
for (Instruction &I : *To) {
if (!isa<PHINode>(I))
break;
PHINode &Phi = cast<PHINode>(I);
while (Phi.getBasicBlockIndex(From) != -1) {
Value *Deleted = Phi.removeIncomingValue(From, false);
Map[&Phi].push_back(std::make_pair(From, Deleted));
@ -540,10 +534,10 @@ void StructurizeCFG::delPhiValues(BasicBlock *From, BasicBlock *To) {
/// \brief Add a dummy PHI value as soon as we knew the new predecessor
void StructurizeCFG::addPhiValues(BasicBlock *From, BasicBlock *To) {
for (BasicBlock::iterator I = To->begin(), E = To->end();
I != E && isa<PHINode>(*I);) {
PHINode &Phi = cast<PHINode>(*I++);
for (Instruction &I : *To) {
if (!isa<PHINode>(I))
break;
PHINode &Phi = cast<PHINode>(I);
Value *Undef = UndefValue::get(Phi.getType());
Phi.addIncoming(Undef, From);
}
@ -554,7 +548,6 @@ void StructurizeCFG::addPhiValues(BasicBlock *From, BasicBlock *To) {
void StructurizeCFG::setPhiValues() {
SSAUpdater Updater;
for (const auto &AddedPhi : AddedPhis) {
BasicBlock *To = AddedPhi.first;
const BBVector &From = AddedPhi.second;
@ -563,7 +556,6 @@ void StructurizeCFG::setPhiValues() {
PhiMap &Map = DeletedPhis[To];
for (const auto &PI : Map) {
PHINode *Phi = PI.first;
Value *Undef = UndefValue::get(Phi->getType());
Updater.Initialize(Phi->getType(), "");
@ -573,7 +565,6 @@ void StructurizeCFG::setPhiValues() {
NearestCommonDominator Dominator(DT);
Dominator.addBlock(To);
for (const auto &VI : PI.second) {
Updater.AddAvailableValue(VI.first, VI.second);
Dominator.addAndRememberBlock(VI.first);
}
@ -582,7 +573,6 @@ void StructurizeCFG::setPhiValues() {
Updater.AddAvailableValue(Dominator.result(), Undef);
for (BasicBlock *FI : From) {
int Idx = Phi->getBasicBlockIndex(FI);
assert(Idx != -1);
Phi->setIncomingValue(Idx, Updater.GetValueAtEndOfBlock(FI));
@ -601,10 +591,8 @@ void StructurizeCFG::killTerminator(BasicBlock *BB) {
return;
for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB);
SI != SE; ++SI) {
SI != SE; ++SI)
delPhiValues(BB, *SI);
}
Term->eraseFromParent();
}
@ -618,10 +606,10 @@ void StructurizeCFG::changeExit(RegionNode *Node, BasicBlock *NewExit,
BasicBlock *Dominator = nullptr;
// Find all the edges from the sub region to the exit
for (pred_iterator I = pred_begin(OldExit), E = pred_end(OldExit);
I != E;) {
for (auto BBI = pred_begin(OldExit), E = pred_end(OldExit); BBI != E;) {
// Incrememt BBI before mucking with BB's terminator.
BasicBlock *BB = *BBI++;
BasicBlock *BB = *I++;
if (!SubRegion->contains(BB))
continue;
@ -645,7 +633,6 @@ void StructurizeCFG::changeExit(RegionNode *Node, BasicBlock *NewExit,
// Update the region info
SubRegion->replaceExit(NewExit);
} else {
BasicBlock *BB = Node->getNodeAs<BasicBlock>();
killTerminator(BB);
@ -676,7 +663,6 @@ BasicBlock *StructurizeCFG::needPrefix(bool NeedEmpty) {
killTerminator(Entry);
if (!NeedEmpty || Entry->getFirstInsertionPt() == Entry->end())
return Entry;
}
// create a new flow node
@ -691,13 +677,13 @@ BasicBlock *StructurizeCFG::needPrefix(bool NeedEmpty) {
/// \brief Returns the region exit if possible, otherwise just a new flow node
BasicBlock *StructurizeCFG::needPostfix(BasicBlock *Flow,
bool ExitUseAllowed) {
if (Order.empty() && ExitUseAllowed) {
BasicBlock *Exit = ParentRegion->getExit();
DT->changeImmediateDominator(Exit, Flow);
addPhiValues(Flow, Exit);
return Exit;
}
return getNextFlow(Flow);
if (!Order.empty() || !ExitUseAllowed)
return getNextFlow(Flow);
BasicBlock *Exit = ParentRegion->getExit();
DT->changeImmediateDominator(Exit, Flow);
addPhiValues(Flow, Exit);
return Exit;
}
/// \brief Set the previous node
@ -706,16 +692,12 @@ void StructurizeCFG::setPrevNode(BasicBlock *BB) {
: nullptr;
}
/// \brief Does BB dominate all the predicates of Node ?
/// \brief Does BB dominate all the predicates of Node?
bool StructurizeCFG::dominatesPredicates(BasicBlock *BB, RegionNode *Node) {
BBPredicates &Preds = Predicates[Node->getEntry()];
for (BBPredicates::iterator PI = Preds.begin(), PE = Preds.end();
PI != PE; ++PI) {
if (!DT->dominates(BB, PI->first))
return false;
}
return true;
return llvm::all_of(Preds, [&](std::pair<BasicBlock *, Value *> Pred) {
return DT->dominates(BB, Pred.first);
});
}
/// \brief Can we predict that this node will always be called?
@ -727,13 +709,14 @@ bool StructurizeCFG::isPredictableTrue(RegionNode *Node) {
if (!PrevNode)
return true;
for (BBPredicates::iterator I = Preds.begin(), E = Preds.end();
I != E; ++I) {
for (std::pair<BasicBlock*, Value*> Pred : Preds) {
BasicBlock *BB = Pred.first;
Value *V = Pred.second;
if (I->second != BoolTrue)
if (V != BoolTrue)
return false;
if (!Dominated && DT->dominates(I->first, PrevNode->getEntry()))
if (!Dominated && DT->dominates(BB, PrevNode->getEntry()))
Dominated = true;
}
@ -848,30 +831,26 @@ void StructurizeCFG::createFlow() {
/// no longer dominate all their uses. Not sure if this is really nessasary
void StructurizeCFG::rebuildSSA() {
SSAUpdater Updater;
for (auto *BB : ParentRegion->blocks())
for (BasicBlock::iterator II = BB->begin(), IE = BB->end();
II != IE; ++II) {
for (BasicBlock *BB : ParentRegion->blocks())
for (Instruction &I : *BB) {
bool Initialized = false;
for (auto I = II->use_begin(), E = II->use_end(); I != E;) {
Use &U = *I++;
for (Use &U : I.uses()) {
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))
if (DT->dominates(&I, User))
continue;
if (!Initialized) {
Value *Undef = UndefValue::get(II->getType());
Updater.Initialize(II->getType(), "");
Value *Undef = UndefValue::get(I.getType());
Updater.Initialize(I.getType(), "");
Updater.AddAvailableValue(&Func->getEntryBlock(), Undef);
Updater.AddAvailableValue(BB, &*II);
Updater.AddAvailableValue(BB, &I);
Initialized = true;
}
Updater.RewriteUseAfterInsertions(U);