On Fri, 9 Feb 2018, Jason Merrill wrote:
> OK.
Failed to notice that vec_safe_reserve reserves additional space
so applied as follows restricting it to the very first iteration.
Richard.
2018-02-12 Richard Biener <rguent...@suse.de>
PR c++/84281
* constexpr.c (cxx_eval_vec_init_1): Use a RANGE_EXPR to compact
uniform constructors and delay allocating them fully.
Index: gcc/cp/constexpr.c
===================================================================
--- gcc/cp/constexpr.c (revision 257525)
+++ gcc/cp/constexpr.c (working copy)
@@ -2885,7 +2885,6 @@ cxx_eval_vec_init_1 (const constexpr_ctx
unsigned HOST_WIDE_INT max = tree_to_uhwi (array_type_nelts_top (atype));
verify_ctor_sanity (ctx, atype);
vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor);
- vec_alloc (*p, max + 1);
bool pre_init = false;
unsigned HOST_WIDE_INT i;
@@ -2978,13 +2977,14 @@ cxx_eval_vec_init_1 (const constexpr_ctx
{
if (new_ctx.ctor != ctx->ctor)
eltinit = new_ctx.ctor;
- for (i = 1; i < max; ++i)
- {
- idx = build_int_cst (size_type_node, i);
- CONSTRUCTOR_APPEND_ELT (*p, idx, unshare_constructor (eltinit));
- }
+ tree range = build2 (RANGE_EXPR, size_type_node,
+ build_int_cst (size_type_node, 1),
+ build_int_cst (size_type_node, max - 1));
+ CONSTRUCTOR_APPEND_ELT (*p, range, unshare_constructor (eltinit));
break;
}
+ else if (i == 0)
+ vec_safe_reserve (*p, max);
}
if (!*non_constant_p)
