https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118864
--- Comment #4 from Drea Pinski <pinskia at gcc dot gnu.org> --- Note I have found merging blocks that contain __builtin_unreachable to be helpful in many cases. So we don't want to block merging of all noreturn functions. Also now factoring out calls and operations; we do end up with some cases where we don't want to "merge" them (see PR 126977) in the case where the one specific operands are different (e.g. the __builtin_crc we want to merge them except when the last argument is different).
