1 files changed, 6 insertions, 0 deletions
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 1db074809c8..c125f05478e 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -4597,6 +4597,12 @@ grok_reference_init (tree decl, tree type, tree init, tree *cleanup)
      explicitly); we need to allow the temporary to be initialized
      first.  */
   tmp = initialize_reference (type, init, decl, cleanup, tf_warning_or_error);
+  if (DECL_DECLARED_CONSTEXPR_P (decl))
+    {
+      tmp = cxx_constant_value (tmp);
+      DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl)
+	= reduced_constant_expression_p (tmp);
+    }
 
   if (tmp == error_mark_node)
     return NULL_TREE;