[Bug middle-end/63568] Missed optimization (a & ~mask) | (b & mask) = a ^ ((a ^ b) & mask)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63568

--- Comment #8 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
(In reply to Oleg Endo from comment #7)
> If you decide not to do the transform at the tree level, please change this
> to a target PR and assign it to me.

I have a patch that does the transformation on match-and-simplify.  Let's see
if it can make it in...