Bernd Schmidt wrote:
> We're creating new pseudos, and while we're resizing some data
> structures, we aren't doing it for everything.
> @@ -3983,7 +3983,8 @@ find_moveable_pseudos (void)
>
> last_moveable_pseudo = max_reg_num ();
>
> - fix_reg_equiv_init();
> + fix_reg_equiv_init ();
> + resize_reg_info ();
> regstat_free_n_sets_and_refs ();
> regstat_free_ri ();
> regstat_init_n_sets_and_refs ();
This causes a bootstrap failure on s390 when enabling
-fsched-pressure -fsched-pressure-algorithm=model by default
(not sure why this doesn't show up without that change).
The problem is that resize_reg_info only resizes the data
structure, but leaves it uninitialized. All other uses
of resize_reg_info subsequently fill in that data,
e.g. in ira-costs.c:find_costs_and_classes.
if (!resize_reg_info () && allocno_p
&& pseudo_classes_defined_p && flag_expensive_optimizations)
{
[...]
But because the structure was now already resized in find_moveable_pseudos,
the next call to resize_reg_info returns false, and thus find_costs_and_classes
assumes the info is actually present, but it is uninitialized, which causes
a crash in the subsequent code
pref[ALLOCNO_NUM (a)] = reg_preferred_class (ALLOCNO_REGNO (a));
setup_regno_cost_classes_by_aclass
(ALLOCNO_REGNO (a), pref[ALLOCNO_NUM (a)]);
max_cost_classes_num
= MAX (max_cost_classes_num,
regno_cost_classes[ALLOCNO_REGNO (a)]->num);
since reg_preferred_class returns 255 for the new pseudo.
Bye,
Ulrich
--
Dr. Ulrich Weigand
GNU Toolchain for Linux on System z and Cell BE
ulrich.weig...@de.ibm.com
