https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80004 Bug 80004 depends on bug 49244, which changed state.
Bug 49244 Summary: __sync or __atomic builtins will not emit 'lock bts/btr/btc' https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49244 What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED