[Bug fortran/56872] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[Bug fortran/56872] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[townsend at astro dot wisc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

--- Comment #1 from Rich Townsend <townsend at astro dot wisc.edu> 2013-04-08 06:02:42 UTC ---
Created attachment 29821
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29821
Test program to reproduce the error

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-04-08
                 CC|                            |Joost.VandeVondele at mat
                   |                            |dot ethz.ch
      Known to work|                            |4.7.2
            Summary|Incorrect SUM evaluation,   |[4.8/4.9 Regression]
                   |involving implied-do loop,  |Incorrect SUM evaluation,
                   |with -ffrontend-optimize    |involving implied-do loop,
                   |                            |with -ffrontend-optimize
     Ever Confirmed|0                           |1
      Known to fail|                            |4.8.0, 4.9.0

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tkoenig at gcc dot gnu.org

--- Comment #2 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2013-04-08 14:07:07 UTC ---
Revision 195140 (2013-01-14) is OK; revision 195192 (2013-01-15) is not. Usual
suspect is revision 195179.

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
                 CC|                            |burnus at gcc dot gnu.org
   Target Milestone|---                         |4.8.1

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2013-04-08 16:07:22 UTC ---
(In reply to comment #2)
> Revision 195140 (2013-01-14) is OK; revision 195192 (2013-01-15) is not. Usual
> suspect is revision 195179.

That's for PR 55806, http://gcc.gnu.org/r195179

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> 2013-04-08 16:39:10 UTC ---
Front-end optimization generates for
  print *,SUM([(s**(REAL(k-1)/REAL(m-1)),k=1,m)])
the code:
   D.1918 = s;
   D.1919 = __builtin_powf (D.1918, (((real(kind=4)) (k + -1) / (real(kind=4))
(m + -1))));

Completely ignoring that "k" is a loop variable, which is not even set.

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

Thomas Koenig <tkoenig at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot       |tkoenig at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #5 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2013-04-08 18:25:45 UTC ---
I have a patch.

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

Thomas Koenig <tkoenig at gcc dot gnu.org> changed:

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

--- Comment #6 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2013-04-08 20:02:09 UTC ---
Fixed on trunk and 4.8.

Thanks a lot for the bug report, and sorry for the breakage.

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

--- Comment #7 from Tobias Burnus <burnus at gcc dot gnu.org> 2013-04-08 20:10:54 UTC ---
Author: tkoenig
Date: Mon Apr  8 19:36:43 2013
New Revision: 197610

URL: http://gcc.gnu.org/viewcvs?rev=197610&root=gcc&view=rev
Log:
2013-04-08  Thomas Koenig  <tkoenig@gcc.gnu.org>

    PR fortran/56782
    * frontend-passes.c (callback_reduction):  Dont't do
    any simplification if there is only a single element
    which has an iterator.

2013-04-08  Thomas Koenig  <tkoenig@gcc.gnu.org>

    PR fortran/56782
    * gfortran.dg/array_constructor_44.f90:  New test.


Added:
    trunk/gcc/testsuite/gfortran.dg/array_constructor_44.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/frontend-passes.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

--- Comment #8 from Tobias Burnus <burnus at gcc dot gnu.org> 2013-04-08 20:11:12 UTC ---
Author: tkoenig
Date: Mon Apr  8 20:01:33 2013
New Revision: 197612

URL: http://gcc.gnu.org/viewcvs?rev=197612&root=gcc&view=rev
Log:
2013-04-08  Thomas Koenig  <tkoenig@gcc.gnu.org>

    PR fortran/56782
    Backport from trunk.
    * frontend-passes.c (callback_reduction):  Dont't do
    any simplification if there is only a single element
    which has an iterator.

2013-04-08  Thomas Koenig  <tkoenig@gcc.gnu.org>

    PR fortran/56782
    Backport from trunk.
    * gfortran.dg/array_constructor_44.f90:  New test.


Added:
    branches/gcc-4_8-branch/gcc/testsuite/gfortran.dg/array_constructor_44.f90
Modified:
    branches/gcc-4_8-branch/gcc/fortran/ChangeLog
    branches/gcc-4_8-branch/gcc/fortran/frontend-passes.c
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

--- Comment #9 from Tobias Burnus <burnus at gcc dot gnu.org> 2013-04-08 20:12:37 UTC ---
(In reply to comment #6)
> Fixed on trunk and 4.8.
> Thanks a lot for the bug report, and sorry for the breakage.

Thanks for the patch, Thomas. But please remember to also copy the commit
message from http://gcc.gnu.org/ml/gcc-cvs/current - as the automatic appending
stopped working with the server upgrade.

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[mikael at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

Mikael Morin <mikael at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
                 CC|                            |mikael at gcc dot gnu.org
         Resolution|FIXED                       |

--- Comment #10 from Mikael Morin <mikael at gcc dot gnu.org> 2013-04-10 16:09:38 UTC ---
> -  if (c == NULL)
> +  /* Don't do any simplififcation if we have
> +     - no element in the constructor or
> +     - only have a single element in the array which contains an
> +     iterator.  */
> +
> +  if (c == NULL || (c->iterator != NULL && gfc_constructor_next (c) == NULL))
>      return 0;
> 
I don't think it is enough if there is something after the iterator.
Testcase:


  real    :: s
  integer :: m
  integer :: k

  m = 2
  s = 1000.

  print *,[(s**(REAL(k-1)/REAL(m-1)),k=1,m)]

  print *,SUM([(s**(REAL(k-1)/REAL(m-1)),k=1,m), 0.0])

end program sum_bug

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

--- Comment #11 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2013-04-13 20:56:49 UTC ---
Created attachment 29869
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29869
Updated patch

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[mikael at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

--- Comment #12 from Mikael Morin <mikael at gcc dot gnu.org> 2013-04-19 10:03:55 UTC ---
Author: mikael
Date: Fri Apr 19 09:58:41 2013
New Revision: 198086

URL: http://gcc.gnu.org/viewcvs?rev=198086&root=gcc&view=rev
Log:
2013-04-19  Thomas Koenig  <tkoenig@gcc.gnu.org>
        Mikael Morin  <mikael@gcc.gnu.org>

    PR fortran/56872
    * frontend-passes.c (copy_walk_reduction_arg): Change argument type
    to gfc_constructor.  If it has an iterator, wrap the copy of its
    expression in an array constructor with that iterator.  Don't special
    case function expressions.
    (callback_reduction): Update caller.  Don't return early if there is
    an iterator.

2013-04-19  Thomas Koenig  <tkoenig@gcc.gnu.org>
        Mikael Morin  <mikael@gcc.gnu.org>

    PR fortran/56872
    * gfortran.dg/array_constructor_45.f90:  New test.
    * gfortran.dg/array_constructor_46.f90:  New test.
    * gfortran.dg/array_constructor_47.f90:  New test.
    * gfortran.dg/array_constructor_40.f90:  Adjust number of
    while loops.


Added:
    trunk/gcc/testsuite/gfortran.dg/array_constructor_45.f90
    trunk/gcc/testsuite/gfortran.dg/array_constructor_46.f90
    trunk/gcc/testsuite/gfortran.dg/array_constructor_47.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/frontend-passes.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/array_constructor_40.f90

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[mikael at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

--- Comment #13 from Mikael Morin <mikael at gcc dot gnu.org> 2013-04-22 14:09:00 UTC ---
Author: mikael
Date: Mon Apr 22 14:07:29 2013
New Revision: 198139

URL: http://gcc.gnu.org/viewcvs?rev=198139&root=gcc&view=rev
Log:
2013-04-22  Thomas Koenig  <tkoenig@gcc.gnu.org>
        Mikael Morin  <mikael@gcc.gnu.org>

    PR fortran/56872
    * frontend-passes.c (copy_walk_reduction_arg): Change argument type
    to gfc_constructor.  If it has an iterator, wrap the copy of its
    expression in an array constructor with that iterator.  Don't special
    case function expressions.
    (callback_reduction): Update caller.  Don't return early if there is
    an iterator.

2013-04-22  Thomas Koenig  <tkoenig@gcc.gnu.org>
        Mikael Morin  <mikael@gcc.gnu.org>

    PR fortran/56872
    * gfortran.dg/array_constructor_45.f90:  New test.
    * gfortran.dg/array_constructor_46.f90:  New test.
    * gfortran.dg/array_constructor_47.f90:  New test.
    * gfortran.dg/array_constructor_40.f90:  Adjust number of
    while loops.


Added:
    branches/gcc-4_8-branch/gcc/testsuite/gfortran.dg/array_constructor_45.f90
    branches/gcc-4_8-branch/gcc/testsuite/gfortran.dg/array_constructor_46.f90
    branches/gcc-4_8-branch/gcc/testsuite/gfortran.dg/array_constructor_47.f90
Modified:
    branches/gcc-4_8-branch/gcc/fortran/ChangeLog
    branches/gcc-4_8-branch/gcc/fortran/frontend-passes.c
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_8-branch/gcc/testsuite/gfortran.dg/array_constructor_40.f90

[Bug fortran/56872] [4.8/4.9 Regression] Incorrect SUM evaluation, involving implied-do loop, with -ffrontend-optimize

[mikael at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56872

Mikael Morin <mikael at gcc dot gnu.org> changed:

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

--- Comment #14 from Mikael Morin <mikael at gcc dot gnu.org> 2013-04-22 14:09:29 UTC ---
Fixed again.