c++: Micro-optimize instantiation_dependent_expression_p

This makes instantiation_dependent_expression_p avoid calling
potential_constant_expression when processing_template_decl isn't set
(and hence when value_dependent_expression_p is definitely false).

gcc/cp/ChangeLog:

	* pt.c (instantiation_dependent_expression_p): Check
	processing_template_decl before calling
	potential_constant_expression.

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 60de8e9..0393531 100644 (file)
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -27519,7 +27519,8 @@ bool
 instantiation_dependent_expression_p (tree expression)
 {
   return (instantiation_dependent_uneval_expression_p (expression)
-         || (potential_constant_expression (expression)
+         || (processing_template_decl
+             && potential_constant_expression (expression)
              && value_dependent_expression_p (expression)));
 }