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.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@142017 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 27 insertions, 0 deletions

diff --git a/gcc/ira.c b/gcc/ira.c
index d0232f75a1e..d7f4e3d0dab 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -1695,6 +1695,23 @@ expand_reg_info (int old_size)
     }
 }
 
+/* Return TRUE if there is too high register pressure in the function.
+   It is used to decide when stack slot sharing is worth to do.  */
+static bool
+too_high_register_pressure_p (void)
+{
+  int i;
+  enum reg_class cover_class;
+  
+  for (i = 0; i < ira_reg_class_cover_size; i++)
+    {
+      cover_class = ira_reg_class_cover[i];
+      if (ira_loop_tree_root->reg_pressure[cover_class] > 10000)
+	return true;
+    }
+  return false;
+}
+
 
 
 /* All natural loops.  */
@@ -1709,6 +1726,7 @@ ira (FILE *f)
   int max_regno_before_ira, ira_max_point_before_emit;
   int rebuild_p;
   int saved_flag_ira_algorithm;
+  int saved_flag_ira_share_spill_slots;
   basic_block bb;
 
   timevar_push (TV_IRA);
@@ -1792,6 +1810,13 @@ ira (FILE *f)
   loops_p = ira_build (optimize
 		       && (flag_ira_algorithm == IRA_ALGORITHM_REGIONAL
 			   || flag_ira_algorithm == IRA_ALGORITHM_MIXED));
+
+  saved_flag_ira_share_spill_slots = flag_ira_share_spill_slots;
+  if (too_high_register_pressure_p ())
+    /* It is just wasting compiler's time to pack spilled pseudos into
+       stack slots in this case -- prohibit it.  */ 
+    flag_ira_share_spill_slots = FALSE;
+
   ira_color ();
       
   ira_max_point_before_emit = ira_max_point;
@@ -1902,6 +1927,8 @@ ira (FILE *f)
     fprintf (ira_dump_file, "+++Overall after reload %d\n", ira_overall_cost);
   ira_destroy ();
   
+  flag_ira_share_spill_slots = saved_flag_ira_share_spill_slots;
+
   flow_loops_free (&ira_loops);
   free_dominance_info (CDI_DOMINATORS);
   FOR_ALL_BB (bb)