[Bug tree-optimization/98304] Failure to optimize bitwise arithmetic pattern

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98304

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
> @1 == (@2)-1

Should have been:
@1 == -(@2-1)

maybe check that @1 is a mask.