fix PR5698
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90708 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index 1b93f34..d58b9c9 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -718,6 +718,11 @@
if (PredSI->getSuccessor(PredCase) != DestBB &&
DestSI->getSuccessor(i) != DestBB)
continue;
+
+ // Do not forward this if it already goes to this destination, this would
+ // be an infinite loop.
+ if (PredSI->getSuccessor(PredCase) == DestSucc)
+ continue;
// Otherwise, we're safe to make the change. Make sure that the edge from
// DestSI to DestSucc is not critical and has no PHI nodes.