From patchwork Tue Aug 10 21:46:02 2010
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Subject: patch for compressing living ranges more
From: Vladimir Makarov <vmakarov@redhat.com>
X-Patchwork-Id: 61418
Message-Id: <4C61C89A.7060308@redhat.com>
To: gcc-patches <gcc-patches@gcc.gnu.org>
Date: Tue, 10 Aug 2010 17:46:02 -0400

The following patch from ira-improv branch was approved by Jeff Law.

The patch has been committed into the trunk.

2010-08-10  Vladimir Makarov <vmakarov@redhat.com>

     * ira-live.c: Include sbitmap.h.
     (remove_some_program_points_and_update_live_ranges): Use sbitmaps.
     Compress live ranges even more.


Index: ira-lives.c
===================================================================
--- ira-lives.c	(revision 163079)
+++ ira-lives.c	(working copy)
@@ -37,6 +37,7 @@ along with GCC; see the file COPYING3.  
 #include "toplev.h"
 #include "params.h"
 #include "df.h"
+#include "sbitmap.h"
 #include "sparseset.h"
 #include "ira-int.h"
 
@@ -1308,25 +1309,43 @@ remove_some_program_points_and_update_li
   ira_object_t obj;
   ira_object_iterator oi;
   live_range_t r;
-  bitmap born_or_died;
-  bitmap_iterator bi;
-
-  born_or_died = ira_allocate_bitmap ();
+  sbitmap born_or_dead, born, dead;
+  sbitmap_iterator sbi;
+  bool born_p, dead_p, prev_born_p, prev_dead_p;
+  
+  born = sbitmap_alloc (ira_max_point);
+  dead = sbitmap_alloc (ira_max_point);
+  sbitmap_zero (born);
+  sbitmap_zero (dead);
   FOR_EACH_OBJECT (obj, oi)
     for (r = OBJECT_LIVE_RANGES (obj); r != NULL; r = r->next)
       {
 	ira_assert (r->start <= r->finish);
-	bitmap_set_bit (born_or_died, r->start);
-	bitmap_set_bit (born_or_died, r->finish);
+	SET_BIT (born, r->start);
+	SET_BIT (dead, r->finish);
       }
 
+  born_or_dead = sbitmap_alloc (ira_max_point);
+  sbitmap_a_or_b (born_or_dead, born, dead);
   map = (int *) ira_allocate (sizeof (int) * ira_max_point);
-  n = 0;
-  EXECUTE_IF_SET_IN_BITMAP(born_or_died, 0, i, bi)
-    {
-      map[i] = n++;
-    }
-  ira_free_bitmap (born_or_died);
+  n = -1;
+  prev_born_p = prev_dead_p = false;
+  EXECUTE_IF_SET_IN_SBITMAP (born_or_dead, 0, i, sbi)
+    {
+      born_p = TEST_BIT (born, i);
+      dead_p = TEST_BIT (dead, i);
+      if ((prev_born_p && ! prev_dead_p && born_p && ! dead_p)
+	  || (prev_dead_p && ! prev_born_p && dead_p && ! born_p))
+	map[i] = n;
+      else
+	map[i] = ++n;
+      prev_born_p = born_p;
+      prev_dead_p = dead_p;
+    }
+  sbitmap_free (born_or_dead);
+  sbitmap_free (born);
+  sbitmap_free (dead);
+  n++;
   if (internal_flag_ira_verbose > 1 && ira_dump_file != NULL)
     fprintf (ira_dump_file, "Compressing live ranges: from %d to %d - %d%%\n",
 	     ira_max_point, n, 100 * n / ira_max_point);