https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122735
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #2) > Definitely exposed by r16-5022-ga50b4406e5d64adb . I should mention that combine converts the zero_extend into `(and (subreg) mask)` which is how that commit exposes the issue while only in combine. Note the bug is earlier in fwprop or how REG_EQUAL gets added with an "undefined" value.
