diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 8c5ddee..bde63db 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1257,6 +1257,7 @@
   case TargetLowering::ZeroOrNegativeOneBooleanContent:
     return N->isAllOnesValue() && SExt;
   }
+  llvm_unreachable("Unexpected enumeration.");
 }
 
 /// Try to simplify a setcc built with the specified operands and cc. If it is