https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93507
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- This is somewhat similar to handling of _1 & 0x... in visit_nary_op where we do a vn_reference_lookup on the _1 SSA def RHS in the special "masked" mode, but that only working when the not masked part is constant.
