[Bug bootstrap/11593] New: [3.4 regression] infinite loop in find_rgns compiling c-parse.c

[Bug bootstrap/11593] New: [3.4 regression] infinite loop in find_rgns compiling c-parse.c

[danglin at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11593

           Summary: [3.4 regression] infinite loop in find_rgns compiling c-
                    parse.c
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: danglin at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: hppa64-hp-hpux11.11
  GCC host triplet: hppa64-hp-hpux11.11
GCC target triplet: hppa64-hp-hpux11.11

stage1/xgcc -Bstage1/ -B/opt/gnu64/hppa64-hp-hpux11.11/bin/   -g -O2 -DIN_GCC
-W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno
-long-long -Werror -fno-common -Wno-error  -DHAVE_CONFIG_H    -I. -I. -I../../gc
c/gcc -I../../gcc/gcc/. -I../../gcc/gcc/config -I../../gcc/gcc/../include  \
       -c ../../gcc/gcc/c-parse.c -o c-parse.o
/opt/gnu/share/bison/bison.simple: In function `yyparse':
/opt/gnu/share/bison/bison.simple:923: warning: label `yyoverflowlab' defined bu
t not used
xgcc: Internal error: Quit (program cc1)

When compiling c_parse_file, a call is made find_rgns with out_edges[0] == 0.
This results in the infinite loop.  This occurs in the while (1) loop.

This problem has been introduced in the last couple of days.

[Bug bootstrap/11593] [3.4 regression] infinite loop in find_rgns compiling c-parse.c

[danglin at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11593


danglin at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rakdver at atrey dot karlin
                   |                            |dot mff dot cuni dot cz


------- Additional Comments From danglin at gcc dot gnu dot org  2003-07-19 20:23 -------
The regression was introduced by this change:

2003-07-19  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>

        * Makefile.in (ifcvt.o): Add cfgloop.h.
        * basic-block.h (EDGE_LOOP_EXIT): New flag.
        * cfgrtl.c (rtl_verify_flow_info_1): Handle it correctly.
        * ifcvt.c: Include cfgloop.h.
        (mark_loop_exit_edges): New static function.
        (if_convert): Call it.
        (find_if_header): Ignore branches out of loops.

[Bug bootstrap/11593] [3.4 regression] infinite loop in find_rgns compiling c-parse.c

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11593


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Priority|P3                          |P1
   Last reconfirmed|0000-00-00 00:00:00         |2003-07-19 20:28:15
               date|                            |


------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-19 20:28 -------
It also introduced other regressions: <http://gcc.gnu.org/ml/gcc-patches/2003-07/
msg01957.html>. 
Here is the original patch and discussion: <http://gcc.gnu.org/ml/gcc-patches/2003-07/
msg01574.html>.

 I say we start the 48 hours now to revert this if there is no hope of getting this fixed soon.

[Bug bootstrap/11593] [3.4 regression] infinite loop in find_rgns compiling c-parse.c

[dave at hiauly1 dot hia dot nrc dot ca]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11593



------- Additional Comments From dave at hiauly1 dot hia dot nrc dot ca  2003-07-19 20:49 -------
Subject: Re:  [3.4 regression] infinite loop in find_rgns

>  I say we start the 48 hours now to revert this if there is no hope of
> getting this fixed soon.

Agreed.  A number of new timeouts occurred in the testsuite of my last
hppa-linux build.  I haven't had a chance to look at them but they may
be caused by the same problem.

Dave

[Bug bootstrap/11593] [3.4 regression] infinite loop in find_rgns compiling c-parse.c

[rakdver at atrey dot karlin dot mff dot cuni dot cz]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11593



------- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni dot cz  2003-07-19 21:35 -------
Subject: Re:  [3.4 regression] infinite loop in find_rgns compiling c-parse.c

Hello,

> PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11593
> 
> 
> pinskia at physics dot uc dot edu changed:
> 
>            What    |Removed                     |Added
> ----------------------------------------------------------------------------
>              Status|UNCONFIRMED                 |NEW
>      Ever Confirmed|                            |1
>            Priority|P3                          |P1
>    Last reconfirmed|0000-00-00 00:00:00         |2003-07-19 20:28:15
>                date|                            |
> 
> 
> ------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-19 20:28 -------
> It also introduced other regressions: <http://gcc.gnu.org/ml/gcc-patches/2003-07/
> msg01957.html>. 
> Here is the original patch and discussion: <http://gcc.gnu.org/ml/gcc-patches/2003-07/
> msg01574.html>.
> 
>  I say we start the 48 hours now to revert this if there is no hope of
>  getting this fixed soon.

the find_rgns function incorrectly assumes that the first block of
function has number zero. Provided that it passes testing, I will
commit the following patch as obvious.

Zdenek

Index: sched-rgn.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/sched-rgn.c,v
retrieving revision 1.62
diff -c -3 -p -r1.62 sched-rgn.c
*** sched-rgn.c	19 Jul 2003 14:47:13 -0000	1.62
--- sched-rgn.c	19 Jul 2003 21:30:41 -0000
*************** find_rgns (struct edge_list *edge_list, 
*** 618,624 ****
    int *max_hdr, *dfs_nr, *stack, *degree;
    char no_loops = 1;
    int node, child, loop_head, i, head, tail;
!   int count = 0, sp, idx = 0, current_edge = out_edges[0];
    int num_bbs, num_insns, unreachable;
    int too_large_failure;
    basic_block bb;
--- 618,625 ----
    int *max_hdr, *dfs_nr, *stack, *degree;
    char no_loops = 1;
    int node, child, loop_head, i, head, tail;
!   int count = 0, sp, idx = 0;
!   int current_edge = out_edges[ENTRY_BLOCK_PTR->succ->dest->index];
    int num_bbs, num_insns, unreachable;
    int too_large_failure;
    basic_block bb;

[Bug bootstrap/11593] [3.4 regression] infinite loop in find_rgns compiling c-parse.c

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11593


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-24 21:17 -------
The patch went in and fixed the regression.

[Bug bootstrap/11593] [3.4 regression] infinite loop in find_rgns compiling c-parse.c

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-09-20 22:52 -------
Subject: Bug 11593

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_3-branch
Changes by:	sayle@gcc.gnu.org	2004-09-20 22:52:38

Modified files:
	gcc            : ChangeLog sched-rgn.c 

Log message:
	PR rtl-optimization/17363
	Backport from mainline
	2003-07-19  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
	
	PR bootstrap/11593
	* sched-rgn.c (find_rgns): Initialize current_edge correctly.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.16114.2.1017&r2=1.16114.2.1018
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/sched-rgn.c.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.50.2.1&r2=1.50.2.2



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11593