Teach LoopUnroll how to bail if LoopSimplify can't give it what it needs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86164 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2009-11-05 19:44:06 +00:00
parent 6a02fc3070
commit 692ad8dd06

View File

@ -108,8 +108,19 @@ static BasicBlock *FoldBlockIntoPredecessor(BasicBlock *BB, LoopInfo* LI) {
bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM) {
assert(L->isLCSSAForm());
BasicBlock *Header = L->getHeader();
BasicBlock *Preheader = L->getLoopPreheader();
if (!Preheader) {
DEBUG(errs() << " Can't unroll; loop preheader-insertion failed.\n");
return false;
}
BasicBlock *LatchBlock = L->getLoopLatch();
if (!LatchBlock) {
DEBUG(errs() << " Can't unroll; loop exit-block-insertion failed.\n");
return false;
}
BasicBlock *Header = L->getHeader();
BranchInst *BI = dyn_cast<BranchInst>(LatchBlock->getTerminator());
if (!BI || BI->isUnconditional()) {