diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 382bfe5..1a44cd0 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -812,7 +812,7 @@
     return false;
   }
 
-  bool VisitCallExpr(const CallExpr *E);
+  bool VisitCallExpr(CallExpr *E);
   bool VisitBinaryOperator(const BinaryOperator *E);
   bool VisitUnaryOperator(const UnaryOperator *E);
   bool VisitConditionalOperator(const ConditionalOperator *E);
@@ -967,7 +967,7 @@
   return -1;
 }
 
-bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
+bool IntExprEvaluator::VisitCallExpr(CallExpr *E) {
   switch (E->isBuiltinCall(Info.Ctx)) {
   default:
     return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
@@ -1022,6 +1022,9 @@
     Operand = Info.Ctx.Target.getEHDataRegisterNumber(Operand);
     return Success(Operand, E);
   }
+
+  case Builtin::BI__builtin_expect:
+    return Visit(E->getArg(0));
   }
 }
 
diff --git a/test/Sema/const-eval.c b/test/Sema/const-eval.c
index fee8d97..9c53725 100644
--- a/test/Sema/const-eval.c
+++ b/test/Sema/const-eval.c
@@ -75,3 +75,4 @@
 EVAL_EXPR(36, constbool)
 
 EVAL_EXPR(37, (1,2.0) == 2.0)
+EVAL_EXPR(38, __builtin_expect(1,1) == 1)