https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71660
--- Comment #3 from Thiago Macieira <thiago at kde dot org> --- (In reply to Jakub Jelinek from comment #1) > Foir double-word compare and exchange you need double-word alignment, so I > think the current alignment is correct. The instruction manual says that CMPXCHG16B requires 128-bit alignment, but doesn't say the same for CMPXCHG8B. It says that the AC(0) alignment check fault could happen if it's not aligned, but doesn't say what the required alignment is.
