various code cleanups, enhance MergeBlockIntoPredecessor to preserve

loop info.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123074 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-01-08 19:08:40 +00:00
parent a1ae0c74af
commit dc85f8ab80

View File

@ -110,7 +110,7 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, Pass *P) {
if (isa<InvokeInst>(PredBB->getTerminator())) return false; if (isa<InvokeInst>(PredBB->getTerminator())) return false;
succ_iterator SI(succ_begin(PredBB)), SE(succ_end(PredBB)); succ_iterator SI(succ_begin(PredBB)), SE(succ_end(PredBB));
BasicBlock* OnlySucc = BB; BasicBlock *OnlySucc = BB;
for (; SI != SE; ++SI) for (; SI != SE; ++SI)
if (*SI != OnlySucc) { if (*SI != OnlySucc) {
OnlySucc = 0; // There are multiple distinct successors! OnlySucc = 0; // There are multiple distinct successors!
@ -131,10 +131,8 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, Pass *P) {
} }
// Begin by getting rid of unneeded PHIs. // Begin by getting rid of unneeded PHIs.
while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) { if (isa<PHINode>(BB->front()))
PN->replaceAllUsesWith(PN->getIncomingValue(0)); FoldSingleEntryPHINodes(BB);
BB->getInstList().pop_front(); // Delete the phi node...
}
// Delete the unconditional branch from the predecessor... // Delete the unconditional branch from the predecessor...
PredBB->getInstList().pop_back(); PredBB->getInstList().pop_back();
@ -152,11 +150,9 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, Pass *P) {
// Finally, erase the old block and update dominator info. // Finally, erase the old block and update dominator info.
if (P) { if (P) {
if (DominatorTree* DT = P->getAnalysisIfAvailable<DominatorTree>()) { if (DominatorTree *DT = P->getAnalysisIfAvailable<DominatorTree>()) {
DomTreeNode* DTN = DT->getNode(BB); if (DomTreeNode *DTN = DT->getNode(BB)) {
DomTreeNode* PredDTN = DT->getNode(PredBB); DomTreeNode *PredDTN = DT->getNode(PredBB);
if (DTN) {
SmallPtrSet<DomTreeNode*, 8> Children(DTN->begin(), DTN->end()); SmallPtrSet<DomTreeNode*, 8> Children(DTN->begin(), DTN->end());
for (SmallPtrSet<DomTreeNode*, 8>::iterator DI = Children.begin(), for (SmallPtrSet<DomTreeNode*, 8>::iterator DI = Children.begin(),
DE = Children.end(); DI != DE; ++DI) DE = Children.end(); DI != DE; ++DI)
@ -164,12 +160,13 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, Pass *P) {
DT->eraseNode(BB); DT->eraseNode(BB);
} }
if (LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>())
LI->removeBlock(BB);
} }
} }
BB->eraseFromParent(); BB->eraseFromParent();
return true; return true;
} }
@ -276,7 +273,7 @@ BasicBlock *llvm::SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P) {
// The new block lives in whichever loop the old one did. This preserves // The new block lives in whichever loop the old one did. This preserves
// LCSSA as well, because we force the split point to be after any PHI nodes. // LCSSA as well, because we force the split point to be after any PHI nodes.
if (LoopInfo* LI = P->getAnalysisIfAvailable<LoopInfo>()) if (LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>())
if (Loop *L = LI->getLoopFor(Old)) if (Loop *L = LI->getLoopFor(Old))
L->addBasicBlockToLoop(New, LI->getBase()); L->addBasicBlockToLoop(New, LI->getBase());