[Bug rtl-optimization/50904] Induct benchmark of polyhedron slows down when -fno-protect-parens is enabled by -Ofast.

dominiq at lps dot ens.fr gcc-bugzilla@gcc.gnu.org
Fri Oct 28 19:14:00 GMT 2011


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50904

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-10-28
                 CC|                            |burnus@net-b.de
     Ever Confirmed|0                           |1

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-10-28 19:14:18 UTC ---
On a Core2Duo the run time when induct is compiled with -Ofast is 14.76s, when
it is compiled with -fprotect-parens -Ofast, the run time is 14.29.

> Please provide your suggestions.

As discussed with Tobias Burnus, I think the inclusion of -fno-protect-parens
in -Ofast was a poor choice. I'ld like to see it reverted, not on the ground of
speed, but because it violates one of the basic requirement of the Fortran
standard (BTW it breaks two of my codes).



More information about the Gcc-bugs mailing list