[Bug tree-optimization/60766] [4.8/4.9 Regression] Wrong optimization with -O2

[Bug tree-optimization/60766] [4.8/4.9 Regression] Wrong optimization with -O2

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
             Target|                            |x86_64-*-*-*
      Known to work|                            |4.4.5
   Target Milestone|---                         |4.8.3
            Summary|Wrong optimization with -O2 |[4.8/4.9 Regression] Wrong
                   |                            |optimization with -O2
      Known to fail|                            |4.9.0

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Looks like IV-opt is creating some overflows that were not there in the
original code.

Fails with:
g++ (GCC) 4.9.0 20131026 (experimental) [trunk revision 204095]


I have not updated my compiler since then.

[Bug tree-optimization/60766] [4.8/4.9 Regression] Wrong optimization with -O2

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Joost.VandeVondele at mat dot ethz
                   |                            |.ch
      Known to fail|4.9.0                       |4.7.2, 4.8.3

--- Comment #2 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
fails for me with the (old) 4.7, 4.8 branch, works with 4.9.

gcc version 4.7.2 20120816 (prerelease) [gcc-4_7-branch revision 190437] (GCC)
: fail
gcc version 4.8.3 20140315 (prerelease) [gcc-4_8-branch revision 208588] : fail
gcc version 4.9.0 20140405 (experimental) [trunk revision 209137] (GCC) : OK

[Bug tree-optimization/60766] [4.8/4.9 Regression] Wrong optimization with -O2

[netheril96 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

netheril96 at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |netheril96 at gmail dot com

--- Comment #3 from netheril96 at gmail dot com ---
The bug is easily reproducible. It has the same behavior with gcc 4.7.3 on my
Ubuntu. I hope this bug can be fixed soon, since the source code is so simple,
and hence the bug may affect a lot of innocent programs.

[Bug tree-optimization/60766] [4.8/4.9 Regression] Wrong optimization with -O2

[mikpelinux at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

Mikael Pettersson <mikpelinux at gmail dot com> changed:

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

--- Comment #4 from Mikael Pettersson <mikpelinux at gmail dot com> ---
Created attachment 32552
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32552&action=edit
self-contained test case, compilable as C and C++

The wrong-code reproduces for me with gcc 4.7 and 4.8 on x86_64-linux.  For
trunk it was fixed by r204515, which doesn't appear to be a wrong-code fix. 
Backporting r204515 to 4.8 fixes the wrong-code there too, but I haven't tested
it beyond this test case.

[Bug tree-optimization/60766] [4.7/4.8/4.9 Regression] Wrong optimization with -O2

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-04-07
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
I will have a look.

[Bug tree-optimization/60766] [4.7/4.8/4.9 Regression] Wrong optimization with -O2

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Mon Apr  7 14:03:55 2014
New Revision: 209190

URL: http://gcc.gnu.org/viewcvs?rev=209190&root=gcc&view=rev
Log:
2014-04-07  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/60766
    * tree-ssa-loop-ivopts.c (cand_value_at): Compute in an
    unsigned type.
    (may_eliminate_iv): Convert cand_value_at result to desired
    type.

    * gcc.dg/torture/pr60766.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr60766.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-loop-ivopts.c

[Bug tree-optimization/60766] [4.7/4.8 Regression] Wrong optimization with -O2

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
      Known to work|                            |4.9.0
            Summary|[4.7/4.8/4.9 Regression]    |[4.7/4.8 Regression] Wrong
                   |Wrong optimization with -O2 |optimization with -O2

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk sofar.

[Bug tree-optimization/60766] [4.7/4.8 Regression] Wrong optimization with -O2

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue May  6 09:02:08 2014
New Revision: 210099

URL: http://gcc.gnu.org/viewcvs?rev=210099&root=gcc&view=rev
Log:
2014-05-06  Richard Biener  <rguenther@suse.de>

    Backport from mainline
    2014-04-17  Richard Biener  <rguenther@suse.de>

    PR middle-end/60849
    * tree-ssa-propagate.c (valid_gimple_rhs_p): Only allow effective
    boolean results for comparisons.

    * g++.dg/opt/pr60849.C: New testcase.

    2014-04-07  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/60766
    * tree-ssa-loop-ivopts.c (cand_value_at): Compute in an
    unsigned type.
    (may_eliminate_iv): Convert cand_value_at result to desired
    type.

    * gcc.dg/torture/pr60766.c: New testcase.

    2014-04-23  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/60903
    * tree-ssa-loop-im.c (execute_sm_if_changed): Properly apply
    IRREDUCIBLE_LOOP loop flags to newly created BBs and edges.

    * gcc.dg/torture/pr60903.c: New testcase.

Added:
    branches/gcc-4_8-branch/gcc/testsuite/g++.dg/opt/pr60849.C
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/torture/pr60766.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/torture/pr60903.c
Modified:
    branches/gcc-4_8-branch/gcc/ChangeLog
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_8-branch/gcc/tree-ssa-loop-im.c
    branches/gcc-4_8-branch/gcc/tree-ssa-loop-ivopts.c
    branches/gcc-4_8-branch/gcc/tree-ssa-propagate.c

[Bug tree-optimization/60766] [4.7 Regression] Wrong optimization with -O2

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.8.3
   Target Milestone|4.8.3                       |4.7.4
            Summary|[4.7/4.8 Regression] Wrong  |[4.7 Regression] Wrong
                   |optimization with -O2       |optimization with -O2
      Known to fail|4.8.3                       |4.8.2

[Bug tree-optimization/60766] [4.7 Regression] Wrong optimization with -O2

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60766

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|4.7.4                       |4.8.3
      Known to fail|                            |4.7.4

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed for 4.8.3.