Index: lib/Analysis/LoopInfo.cpp
===================================================================
--- lib/Analysis/LoopInfo.cpp
+++ lib/Analysis/LoopInfo.cpp
@@ -360,7 +360,8 @@
 }
 
 BranchInst *Loop::getLoopGuardBranch() const {
-  assert(isLoopSimplifyForm() && "Only valid for loop in simplify form");
+  if (!isLoopSimplifyForm())
+    return nullptr;
   BasicBlock *Preheader = getLoopPreheader();
   BasicBlock *Latch = getLoopLatch();
   assert(Preheader && Latch &&