[Bug c++/79373] For loop optimization bug: condition ignored

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79373

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I am suspecting this:
        t*=65793;

overflows.

Can you try with -fsanitize=undefined ?