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

[dominiq at lps dot ens.fr]

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

--- Comment #5 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
> My guess is that -fstack-arrays makes the difference.

Confirmed:

[Book15] lin/test% gfc -Ofast -fwhole-program fatigue.f90 -fno-stack-arrays
[Book15] lin/test% time a.out > /dev/null
2.982u 0.001s 0:02.98 100.0%    0+0k 0+1io 0pf+0w