[Bug tree-optimization/112104] loop of ^1 should just be reduced to ^(n&1)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112104

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This shows up in a really really bad benchmark:
https://github.com/kdlucas/byte-unixbench/blob/master/UnixBench/src/whets.c