This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH][C++] Save memory/time when folding CONSTRUCTORs
On Wed, 1 Feb 2017, Nathan Sidwell wrote:
> On 02/01/2017 10:18 AM, Richard Biener wrote:
>
> > True. Updated patch below.
> >
> > Richard.
> >
> > 2017-02-01 Richard Biener <rguenther@suse.de>
> >
> > PR cp/14179
> > cp/
> > * cp-gimplify.c (cp_fold): When folding a CONSTRUCTOR copy
> > it lazily on the first changed element only and copy it
> > fully upfront, only storing changed elements.
>
> Looks good, with the tweak Jakub noticed.
And one more tweak, I have to free it for the error_mark_case.
(vec_free sets nelts to NULL)
Richard.
2017-02-01 Richard Biener <rguenther@suse.de>
PR cp/14179
cp/
* cp-gimplify.c (cp_fold): When folding a CONSTRUCTOR copy
it lazily on the first changed element only and copy it
fully upfront, only storing changed elements.
Index: gcc/cp/cp-gimplify.c
===================================================================
--- gcc/cp/cp-gimplify.c (revision 245096)
+++ gcc/cp/cp-gimplify.c (working copy)
@@ -2358,30 +2358,26 @@ cp_fold (tree x)
{
unsigned i;
constructor_elt *p;
- bool changed = false;
vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (x);
vec<constructor_elt, va_gc> *nelts = NULL;
- vec_safe_reserve (nelts, vec_safe_length (elts));
FOR_EACH_VEC_SAFE_ELT (elts, i, p)
{
tree op = cp_fold (p->value);
- constructor_elt e = { p->index, op };
- nelts->quick_push (e);
if (op != p->value)
{
if (op == error_mark_node)
{
x = error_mark_node;
- changed = false;
+ vec_free (nelts);
break;
}
- changed = true;
+ if (nelts == NULL)
+ nelts = elts->copy ();
+ (*nelts)[i].value = op;
}
}
- if (changed)
+ if (nelts)
x = build_constructor (TREE_TYPE (x), nelts);
- else
- vec_free (nelts);
break;
}
case TREE_VEC: