[IR] Handle constant expressions in containsUndefinedElement()

If the constant is a constant expression, then getAggregateElement()
will return null. Guard against this before calling HasFn().

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/IR/Constants.cpp b/llvm/lib/IR/Constants.cpp
index b543cbc..c2e91f1 100644
--- a/llvm/lib/IR/Constants.cpp
+++ b/llvm/lib/IR/Constants.cpp
@@ -315,9 +315,11 @@ containsUndefinedElement(const Constant *C,
       return false;
 
     for (unsigned i = 0, e = cast<FixedVectorType>(VTy)->getNumElements();
-         i != e; ++i)
-      if (HasFn(C->getAggregateElement(i)))
-        return true;
+         i != e; ++i) {
+      if (Constant *Elem = C->getAggregateElement(i))
+        if (HasFn(Elem))
+          return true;
+    }
   }
 
   return false;