On Thu, Mar 10, 2016 at 06:37:32PM +0100, Jakub Jelinek wrote:
> On Thu, Mar 10, 2016 at 12:34:40PM -0500, Patrick Palka wrote:
> > Doesn't this mean that we call initializer_constant_valid_p at each
> > iteration? This would slow down the non-constant case even further.
> > So I wonder if the return value of initializer_constant_valid_p could
> > be cached or something, since it seems like a potentially expensive
> > predicate.
>
> You're right, but I've already committed the patch. I'll write an
> incremental patch and test it.
So, like this?
2016-03-10 Jakub Jelinek <ja...@redhat.com>
PR c++/70001
* constexpr.c (cxx_eval_vec_init_1): For pre_init, only
call initializer_constant_valid_p on the first iteration.
--- gcc/cp/constexpr.c.jj 2016-03-10 12:52:04.000000000 +0100
+++ gcc/cp/constexpr.c 2016-03-10 18:45:13.416533853 +0100
@@ -2391,17 +2391,21 @@ cxx_eval_vec_init_1 (const constexpr_ctx
/* Initializing an element using value or default initialization
we just pre-built above. */
if (pre_init_elt == NULL_TREE)
- pre_init_elt
- = cxx_eval_constant_expression (&new_ctx, init, lval,
- non_constant_p, overflow_p);
- eltinit = pre_init_elt;
- /* Don't reuse the result of cxx_eval_constant_expression
- call if it isn't a constant initializer or if it requires
- relocations. */
- if (initializer_constant_valid_p (pre_init_elt,
- TREE_TYPE (pre_init_elt))
- != null_pointer_node)
- pre_init_elt = NULL_TREE;
+ {
+ eltinit
+ = cxx_eval_constant_expression (&new_ctx, init, lval,
+ non_constant_p, overflow_p);
+ /* Don't reuse the result of cxx_eval_constant_expression
+ call if it isn't a constant initializer or if it requires
+ relocations. */
+ if (i == 0
+ && (initializer_constant_valid_p (eltinit,
+ TREE_TYPE (eltinit))
+ == null_pointer_node))
+ pre_init_elt = eltinit;
+ }
+ else
+ eltinit = pre_init_elt;
}
else
{
Jakub
