[Bug tree-optimization/46561] New: [4.6 Regression] -fcompare-debug failure (length) with -O2 -ftree-vectorize -ftree-parallelize-loops

[Bug tree-optimization/46561] New: [4.6 Regression] -fcompare-debug failure (length) with -O2 -ftree-vectorize -ftree-parallelize-loops

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46561

           Summary: [4.6 Regression] -fcompare-debug failure (length) with
                    -O2 -ftree-vectorize -ftree-parallelize-loops
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
                CC: aoliva@gcc.gnu.org
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 22456
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22456
reduced testcase

Compiler output:
$ gcc -O2 -ftree-vectorize -ftree-parallelize-loops=2 -fcompare-debug pr46561.c 
gcc: error: pr46561.c: -fcompare-debug failure (length)

The dumps are very different, it seems the loop is not parallelized in the -g
case.

Tested revisions:
r166899 - fail
r163636 - fail
r161659 - OK
4.5 r166509 - OK

[Bug tree-optimization/46561] [4.6 Regression] -fcompare-debug failure (length) with -O2 -ftree-vectorize -ftree-parallelize-loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46561

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.11.19 13:16:33
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-11-19 13:16:33 UTC ---
tree-parloop.c is indeed a mess stmt matching-wise.

[Bug tree-optimization/46561] [4.6 Regression] -fcompare-debug failure (length) with -O2 -ftree-vectorize -ftree-parallelize-loops

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46561

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |irar at il dot ibm.com
   Target Milestone|---                         |4.6.0

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2010-11-19 14:59:05 UTC ---
It is caused by revision 161797:

http://gcc.gnu.org/ml/gcc-cvs/2010-07/msg00151.html

[Bug tree-optimization/46561] [4.6 Regression] -fcompare-debug failure (length) with -O2 -ftree-vectorize -ftree-parallelize-loops

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46561

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

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

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-11-19 20:04:14 UTC ---
Mine.

[Bug debug/46561] [4.6 Regression] -fcompare-debug failure (length) with -O2 -ftree-vectorize -ftree-parallelize-loops

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46561

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-11-19 20:19:44 UTC ---
Created attachment 22461
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22461
gcc46-pr46561.patch

Untested fix.

[Bug debug/46561] [4.6 Regression] -fcompare-debug failure (length) with -O2 -ftree-vectorize -ftree-parallelize-loops

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46561

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-11-20 12:14:53 UTC ---
Author: jakub
Date: Sat Nov 20 12:14:48 2010
New Revision: 166975

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=166975
Log:
    PR debug/46561
    * tree-parloops.c (try_create_redunction_list): Ignore debug stmts
    when looking for immediate uses.

    * gcc.dg/autopar/pr46561.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/autopar/pr46561.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-parloops.c

[Bug debug/46561] [4.6 Regression] -fcompare-debug failure (length) with -O2 -ftree-vectorize -ftree-parallelize-loops

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46561

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

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

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-11-20 12:16:06 UTC ---
Fixed.