Index: lib/Analysis/ScalarEvolutionExpander.cpp
===================================================================
--- lib/Analysis/ScalarEvolutionExpander.cpp
+++ lib/Analysis/ScalarEvolutionExpander.cpp
@@ -1746,6 +1746,7 @@
   if (I != InsertedExpressions.end())
     return I->second;
 
+  assert(isSafeToExpand(S, SE) && "Attempt to expand something unsafe!");
   SCEVInsertPointGuard Guard(Builder, this);
   Builder.SetInsertPoint(InsertPt);