diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp index a8aa0e0bbcc..488915e96e2 100644 --- a/lib/Transforms/Utils/LoopSimplify.cpp +++ b/lib/Transforms/Utils/LoopSimplify.cpp @@ -156,12 +156,18 @@ bool LoopSimplify::ProcessLoop(Loop *L) { // Next, check to make sure that all exit nodes of the loop only have // predecessors that are inside of the loop. This check guarantees that the // loop preheader/header will dominate the exit blocks. If the exit block has - // predecessors from outside of the loop, split the edge now. - std::vector ExitBlocks; - L->getExitBlocks(ExitBlocks); - - SetVector ExitBlockSet(ExitBlocks.begin(), ExitBlocks.end()); + // predecessors from outside of the loop, split the edge now. Note that we + // only want to consider the exit blocks of *this* loop, not of any subloops, + // so we can't use Loop::getExitBlocks(). LoopInfo &LI = getAnalysis(); + SetVector ExitBlockSet; + for (Loop::block_iterator BI = L->block_begin(), + BE = L->block_end(); BI != BE; ++BI) + if (LI.getLoopFor(*BI) == L) // not a subloop. + for (succ_iterator I = succ_begin(*BI), E = succ_end(*BI); I != E; ++I) + if (!L->contains(*I)) // Not in current loop? + ExitBlockSet.insert(*I); // It must be an exit block. + for (SetVector::iterator I = ExitBlockSet.begin(), E = ExitBlockSet.end(); I != E; ++I) { BasicBlock *ExitBlock = *I; @@ -169,7 +175,7 @@ bool LoopSimplify::ProcessLoop(Loop *L) { PI != PE; ++PI) // Must be exactly this loop: no subloops, parent loops, or non-loop preds // allowed. - if (!L->contains(*PI)) { + if (LI.getLoopFor(*PI) != L) { RewriteLoopExitBlock(L, ExitBlock); NumInserted++; Changed = true;