flow.c (count_or_remove_death_notes_bb): New.

        * flow.c (count_or_remove_death_notes_bb): New.  Extracted from
        count_or_remove_death_notes.
        (count_or_remove_death_notes): Use EXECUTE_IF_SET_IN_SBITMAP.

From-SVN: r74111

gcc/ChangeLog

+2003-12-01  Jeff Law  <law@redhat.com>
+
+	* flow.c (count_or_remove_death_notes_bb): New.  Extracted from
+	count_or_remove_death_notes.
+	(count_or_remove_death_notes): Use EXECUTE_IF_SET_IN_SBITMAP.
+
 2003-12-01  Andreas Krebbel  <krebbel1@de.ibm.com>
 
 	* builtins.c (expand_builtin_longjmp): Added two memory clobbers.

gcc/flow.c

@@ -326,6 +326,7 @@ static void add_to_mem_set_list (struct propagate_block_info *, rtx);
 static int invalidate_mems_from_autoinc (rtx *, void *);
 static void invalidate_mems_from_set (struct propagate_block_info *, rtx);
 static void clear_log_links (sbitmap);
+static int count_or_remove_death_notes_bb (basic_block, int);
 
 
 void
@@ -4168,14 +4169,43 @@ int
 count_or_remove_death_notes (sbitmap blocks, int kill)
 {
   int count = 0;
+  int i;
   basic_block bb;
 
-  FOR_EACH_BB_REVERSE (bb)
+  
+  /* This used to be a loop over all the blocks with a membership test
+     inside the loop.  That can be amazingly expensive on a large CFG
+     when only a small number of bits are set in BLOCKs (for example,
+     the calls from the scheduler typically have very few bits set).
+
+     For extra credit, someone should convert BLOCKS to a bitmap rather
+     than an sbitmap.  */
+  if (blocks)
     {
-      rtx insn;
+      EXECUTE_IF_SET_IN_SBITMAP (blocks, 0, i,
+	{
+	  count += count_or_remove_death_notes_bb (BASIC_BLOCK (i), kill);
+	});
+    }
+  else
+    {
+      FOR_EACH_BB (bb)
+	{
+	  count += count_or_remove_death_notes_bb (bb, kill);
+	}
+    }
 
-      if (blocks && ! TEST_BIT (blocks, bb->index))
-	continue;
+  return count;
+}
+  
+/* Optionally removes all the REG_DEAD and REG_UNUSED notes from basic
+   block BB.  Returns a count of the number of registers that died.  */
+
+static int
+count_or_remove_death_notes_bb (basic_block bb, int kill)
+{
+  int count = 0;
+  rtx insn;
 
   for (insn = bb->head;; insn = NEXT_INSN (insn))
     {
@@ -4200,6 +4230,7 @@ count_or_remove_death_notes (sbitmap blocks, int kill)
 		        n = HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg));
 		      count += n;
 		    }
+
 		  /* Fall through.  */
 
 		case REG_UNUSED:
@@ -4223,10 +4254,10 @@ count_or_remove_death_notes (sbitmap blocks, int kill)
       if (insn == bb->end)
 	break;
     }
-    }
 
   return count;
 }
+
 /* Clear LOG_LINKS fields of insns in a selected blocks or whole chain
    if blocks is NULL.  */