[Bug tree-optimization/55964] New: Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[Bug tree-optimization/55964] New: Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[antoine.balestrat at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

             Bug #: 55964
           Summary: Segmentation fault with -O -ftree-loop-distribution
                    -funswitch-loops
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: antoine.balestrat@gmail.com


GCC 4.7.2 and 4.8.0 as of 20130112 fail to compile the following testcase with
the flags -O -ftree-loop-distribution -funswitch-loops.

$ cat segfault.c
int a, b;

void f(void)
{
lbl1:
    for(b = 0; b < 1; b++)
    {
        int u = 1;

        if((b %= 0) * (b ? 0 : a) - 1 && (u /= 0))
        {
            int *q = &u, **k = q;
            goto lbl1;
lbl2:
lbl3:
            a = **k;
            goto lbl2;
        }
    }
    goto lbl3;
}

$ xgcc -w -O -ftree-loop-distribution -funswitch-loops segfault.c
segfault.c: In function ‘f’:
segfault.c:3:6: internal compiler error: Segmentation fault
 void f(void)
      ^
0x8da6df crash_signal
    ../../srcdir/gcc/toplev.c:332
0xa8f61b rename_use_op
    ../../srcdir/gcc/tree-vect-loop-manip.c:53
0xa90777 rename_variables_in_bb(basic_block_def*)
    ../../srcdir/gcc/tree-vect-loop-manip.c:93
0xa9082d rename_variables_in_loop(loop*)
    ../../srcdir/gcc/tree-vect-loop-manip.c:109
0x9447e3 copy_loop_before
    ../../srcdir/gcc/tree-loop-distribution.c:220
0x9447e3 generate_loops_for_partition
    ../../srcdir/gcc/tree-loop-distribution.c:254
0x9447e3 generate_code_for_partition
    ../../srcdir/gcc/tree-loop-distribution.c:539
0x947891 ldist_gen
    ../../srcdir/gcc/tree-loop-distribution.c:1405
0x947891 distribute_loop
    ../../srcdir/gcc/tree-loop-distribution.c:1476
0x947891 tree_loop_distribution
    ../../srcdir/gcc/tree-loop-distribution.c:1548
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

[Bug tree-optimization/55964] [4.7/4.8 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-01-14
                 CC|                            |jakub at gcc dot gnu.org
   Target Milestone|---                         |4.7.3
            Summary|Segmentation fault with -O  |[4.7/4.8 Regression]
                   |-ftree-loop-distribution    |Segmentation fault with -O
                   |-funswitch-loops            |-ftree-loop-distribution
                   |                            |-funswitch-loops
     Ever Confirmed|0                           |1

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-01-14 12:34:08 UTC ---
Started with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181172

[Bug tree-optimization/55964] [4.7/4.8 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |rguenth at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> 2013-01-14 13:14:33 UTC ---
Mine.

[Bug tree-optimization/55964] [4.7/4.8 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> 2013-01-16 14:07:03 UTC ---
Author: rguenth
Date: Wed Jan 16 14:06:58 2013
New Revision: 195239

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=195239
Log:
2013-01-16  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/55964
    * tree-flow.h (rename_variables_in_loop): Remove.
    (rename_variables_in_bb): Likewise.
    * tree-loop-distribution.c (update_phis_for_loop_copy): Remove.
    (copy_loop_before): Adjust and delete update-ssa status.
    * tree-vect-loop-manip.c (rename_variables_in_bb): Make static.
    (rename_variables_in_bb): Likewise.  Properly walk over
    predecessors.
    (rename_variables_in_loop): Remove.
    (slpeel_update_phis_for_duplicate_loop): Likewise.
    (slpeel_tree_duplicate_loop_to_edge_cfg): Handle nested loops,
    use available cfg machinery instead of duplicating it.
    Update PHI nodes and perform poor-mans SSA update here.
    (slpeel_tree_peel_loop_to_edge): Adjust.

    * gcc.dg/torture/pr55964.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr55964.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-flow.h
    trunk/gcc/tree-loop-distribution.c
    trunk/gcc/tree-vect-loop-manip.c

[Bug tree-optimization/55964] [4.7 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.7/4.8 Regression]        |[4.7 Regression]
                   |Segmentation fault with -O  |Segmentation fault with -O
                   |-ftree-loop-distribution    |-ftree-loop-distribution
                   |-funswitch-loops            |-funswitch-loops

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-01-16 14:22:49 UTC ---
Fixed for 4.8+ so far.

[Bug tree-optimization/55964] [4.7 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
           Priority|P3                          |P2
      Known to work|                            |4.8.0
      Known to fail|                            |4.7.2

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-03 09:48:00 UTC ---
Backport unlikely.

[Bug tree-optimization/55964] [4.7 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |stijnv at gmail dot com

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-03 09:50:32 UTC ---
*** Bug 56097 has been marked as a duplicate of this bug. ***

[Bug tree-optimization/55964] [4.7 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-03 10:38:26 UTC ---
Author: rguenth
Date: Wed Apr  3 10:36:49 2013
New Revision: 197403

URL: http://gcc.gnu.org/viewcvs?rev=197403&root=gcc&view=rev
Log:
2013-04-03  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/55964
    * gcc.dg/torture/pr55964-2.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr55964-2.c
Modified:
    trunk/gcc/testsuite/ChangeLog

Author: rguenth
Date: Wed Apr  3 10:37:36 2013
New Revision: 197404

URL: http://gcc.gnu.org/viewcvs?rev=197404&root=gcc&view=rev
Log:
2013-04-03  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/55964
    * gcc.dg/torture/pr55964-2.c: New testcase.

Added:
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/torture/pr55964-2.c
Modified:
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog


added testcase from the duplicate.

[Bug tree-optimization/55964] [4.7 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |john at jbeidl dot com

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-08 11:07:55 UTC ---
*** Bug 56851 has been marked as a duplicate of this bug. ***

[Bug tree-optimization/55964] [4.7 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.7.3                       |4.7.4

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-11 07:59:33 UTC ---
GCC 4.7.3 is being released, adjusting target milestone.

[Bug tree-optimization/55964] [4.7 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |NEW
           Assignee|rguenth at gcc dot gnu.org         |unassigned at gcc dot gnu.org

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Not going to backport this.

[Bug tree-optimization/55964] [4.7 Regression] Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|4.7.4                       |4.8.0
      Known to fail|                            |4.7.4

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed for 4.8.0.