[Bug tree-optimization/78482] [5/6/7 Regression] wrong code at -O3 in both 32-bit and 64-bit modes on x86_64-linux-gnu

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78482

--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to David Edelsohn from comment #7)
> Yep, timing out on AIX also.  Is this assuming signed char?

Looks like it from the code.
char c, d;
....
for (; c >= 0; c--)


Simple fix is to just change char to be signed char.