[Bug target/111870] Miscompile of atomic rmw or on x86 (not aarch, though)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111870

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
That is not using the fetch part is optimized to just `lock or`.