[Bug bootstrap/14671] [3.3/3.4 regression] caller-save.c:491: internal compiler error: Segmentation fault

[dave at hiauly1 dot hia dot nrc dot ca]

------- Additional Comments From dave at hiauly1 dot hia dot nrc dot ca  2004-04-07 04:24 -------
Subject: Re:  [3.3/3.4 regression] caller-save.c:491: int

> ------- Additional Comments From mmitchel at gcc dot gnu dot org  2004-04-04
> 23:05 -------
> Dave, can you confirm whether or not this PR is fixed?

I studied this problem further today.  The in_use flag for the node
that causes the segfault is being cleared by clear_marks.  clear_marks
is called from ggc_collect.  ggc_collect is called from loop_optimize.

It would appear that there are a few ggc objects created after the last
context push (possibly in init_alias_once).  These get garbage collected
and cause the segfault.

I believe that the enclosed patch will fix the problem.  The problem
affects 3.3 onward.

The patch is not fully tested.  I'm still struggling with bootstrap/14829.
CVS access for me has been terrible the last couple of days.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)

2004-04-07  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>

	PR bootstrap/14671
	* loop.c (loop_optimize): Push and pop ggc context.

Index: loop.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/loop.c,v
retrieving revision 1.497
diff -u -3 -p -r1.497 loop.c
--- loop.c	18 Mar 2004 16:42:31 -0000	1.497
+++ loop.c	6 Apr 2004 23:27:05 -0000
@@ -498,6 +498,7 @@ loop_optimize (rtx f, FILE *dumpfile, in
      We could have added a call to reg_scan after gcse_main in toplev.c,
      but moving this call to init_alias_analysis is more efficient.  */
   init_alias_analysis ();
+  ggc_push_context ();
 
   /* See if we went too far.  Note that get_max_uid already returns
      one more that the maximum uid of all insn.  */
@@ -543,6 +544,7 @@ loop_optimize (rtx f, FILE *dumpfile, in
 	}
     }
 
+  ggc_pop_context ();
   end_alias_analysis ();
 
   /* Clean up.  */


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14671