LoopIndexSplit can sometimes result in cases where a block in its own domfrontier.
Don't crash when we encounter one of these.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51915 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/BreakCriticalEdges.cpp b/lib/Transforms/Utils/BreakCriticalEdges.cpp
index bc9fdfd..a821423 100644
--- a/lib/Transforms/Utils/BreakCriticalEdges.cpp
+++ b/lib/Transforms/Utils/BreakCriticalEdges.cpp
@@ -235,9 +235,12 @@
DominanceFrontier::iterator I = DF->find(DestBB);
if (I != DF->end()) {
DF->addBasicBlock(NewBB, I->second);
- // However NewBB's frontier does not include DestBB.
- DominanceFrontier::iterator NF = DF->find(NewBB);
- DF->removeFromFrontier(NF, DestBB);
+
+ if (I->second.count(DestBB)) {
+ // However NewBB's frontier does not include DestBB.
+ DominanceFrontier::iterator NF = DF->find(NewBB);
+ DF->removeFromFrontier(NF, DestBB);
+ }
}
else
DF->addBasicBlock(NewBB, DominanceFrontier::DomSetType());