[Bug fortran/48864] New: -Ofast should imply -fno-protect-parens

[Bug fortran/48864] New: -Ofast should imply -fno-protect-parens

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48864

           Summary: -Ofast should imply -fno-protect-parens
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org


-Ofast implies -O3 -ffast-math and possibly some more performance options; it
should also imply -fno-protect-parens

For -Ofast, cf. http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html

For -fno-protect-parens,
cf. http://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html


That -Ofast implies -fno-protect-parens should also be documented for -Ofast.


An example how drastic the performance depends on -fno-protect-parens is the
following program; it additionally requires -funroll-loops:

http://openmp.org/forum/viewtopic.php?f=3&t=1134#p4565

gfortran timings can be found at
  http://openmp.org/forum/viewtopic.php?f=3&t=1134&start=11
  http://openmp.org/forum/viewtopic.php?f=3&t=1134&start=11#p4673

[Bug fortran/48864] -Ofast should imply -fno-protect-parens

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48864

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.05.04 11:33:11
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-04 11:33:11 UTC ---
Confirmed.

[Bug fortran/48864] -Ofast should imply -fno-protect-parens

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48864

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-05-04 17:10:20 UTC ---
Author: burnus
Date: Wed May  4 17:10:15 2011
New Revision: 173385

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173385
Log:
gcc/
2011-05-04  Tobias Burnus  <burnus@net-b.de>

        PR fortran/48864
        * doc/invoke.texi (Ofast): Document that it
        enables Fortran's -fno-protect-parens.

gcc/fortran
2011-05-04  Tobias Burnus  <burnus@net-b.de>

        PR fortran/48864
        * invoke.texi (fno-protect-parens): Document
        that -Ofast implies -fno-protect-parens.
        * options.c (gfc_init_options, gfc_post_options):
        Make -Ofast imply -fno-protect-parens.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/doc/invoke.texi
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/invoke.texi
    trunk/gcc/fortran/options.c

[Bug fortran/48864] -Ofast should imply -fno-protect-parens

[dfranke at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48864

Daniel Franke <dfranke at gcc dot gnu.org> changed:

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

--- Comment #3 from Daniel Franke <dfranke at gcc dot gnu.org> 2011-07-24 19:09:12 UTC ---
Tobias, anything else to do here? Can this be closed?

[Bug fortran/48864] -Ofast should imply -fno-protect-parens

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48864

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

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

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-07-24 19:48:02 UTC ---
(In reply to comment #3)
> Tobias, anything else to do here? Can this be closed?

Yes, it's FIXED.