https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82156
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Second, the return of __atomic_always_lock_free and __atomic_is_lock_free are changed to report false for the affected accesses. This aims at making users aware of the fact that they don't get fast hardware-backed performance for the affected accesses.