[Bug middle-end/64099] [5 Regression] ~15% runtime increase for fatigue.f90.

dominiq at lps dot ens.fr gcc-bugzilla@gcc.gnu.org
Fri Nov 28 13:22:00 GMT 2014


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64099

--- Comment #4 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
> Ugh - -Ofast is an alias for -O3 -ffast-math.  Ah, no - it also enables
> --param allow-store-data-races=1 ...

-Ofast
Disregard strict standards compliance. -Ofast enables all -O3 optimizations. It
also enables optimizations that are not valid for all standard-compliant
programs. It turns on -ffast-math and the Fortran-specific -fno-protect-parens
and -fstack-arrays. 

My guess is that -fstack-arrays makes the difference.



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