The following patch solves PR37790. The problem is described on
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37790
The patch switches stack slot coalescing from usage of bitmaps to
usage of live ranges. It dramatically decreases compilation speed and
memory usage for this test. The patch also prohibits stack slot
sharing and processing pseudos spilled by IRA in reload pass when the
register pressure is too high (more than 10K) to guarantee IRA decent
behavior in extreme cases.
The patch was successfully bootstrapped on x86/x86_64, ppc64, and
itanium.
Ok to submit?
2008-11-15 Vladimir Makarov <vmakarov@redhat.com>
PR bootstrap/37790
* ira-int.h (ira_copy_allocno_live_range_list,
ira_merge_allocno_live_ranges,
ira_allocno_live_ranges_intersect_p,
ira_finish_allocno_live_range_list): New prototypes.
(ira_allocno_live_ranges_intersect_p,
ira_pseudo_live_ranges_intersect_p): Remove.
* ira-conflicts.c (ira_allocno_live_ranges_intersect_p,
ira_pseudo_live_ranges_intersect_p): Rename to
allocnos_have_intersected_live_ranges_p and
pseudos_have_intersected_live_ranges_p. Move them from here to
...
* ira-color.c: ... here
(coalesced_allocno_conflict_p): Use
allocnos_have_intersected_live_ranges_p.
(coalesced_allocnos_living_at_program_points,
coalesced_allocnos_live_at_points_p,
set_coalesced_allocnos_live_points): Remove.
(slot_coalesced_allocnos_live_ranges,
slot_coalesced_allocno_live_ranges_intersect_p,
setup_slot_coalesced_allocno_live_ranges): New.
(coalesce_spill_slots): Use ranges of coalesced allocnos.
(ira_sort_regnos_for_alter_reg): Use
allocnos_have_intersected_live_ranges_p.
(ira_reuse_stack_slot): Use
pseudos_have_intersected_live_ranges_p.
* global.c (pseudo_for_reload_consideration_p): Check
flag_ira_share_spill_slots too.
* ira-build.c (copy_allocno_live_range_list): Rename to
ira_copy_allocno_live_range_list. Make it external.
(merge_ranges): Rename to ira_merge_allocno_live_ranges. Make it
external.
(ira_allocno_live_ranges_intersect_p): New.
(ira_finish_allocno_live_range_list): New.
(finish_allocno): Use it.
(remove_unnecessary_allocnos): Use ira_merge_allocno_live_ranges.
(copy_info_to_removed_store_destinations): Ditto. Use
ira_copy_allocno_live_range_list.
(ira_flattening): Use ira_merge_allocno_live_ranges.
* ira.c (too_high_register_pressure_p): New function.
(ira): Switch off sharing spill slots if the pressure is too high.