https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54005
--- Comment #16 from Hans-Peter Nilsson <hp at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #14) > Can we close this? No. IIUC, we're still/again using __atomic_is_lock_free with alignment deduced from the current object rather than the type (even though it's now a proxy-object; the faked pointer is constructed from the alignment of the current object). So, r221701 was wrong to change from null to the alignment-deduced fake-pointer.