fix PR9523, a crash in looprotate on a non-canonical loop made out of indirectbr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129203 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopRotation.cpp b/lib/Transforms/Scalar/LoopRotation.cpp
index 95e1578..e7b1a03 100644
--- a/lib/Transforms/Scalar/LoopRotation.cpp
+++ b/lib/Transforms/Scalar/LoopRotation.cpp
@@ -184,7 +184,11 @@
// Now, this loop is suitable for rotation.
BasicBlock *OrigPreheader = L->getLoopPreheader();
BasicBlock *OrigLatch = L->getLoopLatch();
- assert(OrigPreheader && OrigLatch && "Loop not in canonical form?");
+
+ // If the loop could not be converted to canonical form, it must have an
+ // indirectbr in it, just give up.
+ if (OrigPreheader == 0 || OrigLatch == 0)
+ return false;
// Anything ScalarEvolution may know about this loop or the PHI nodes
// in its header will soon be invalidated.