https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113772
--- Comment #6 from Iain Sandoe <iains at gcc dot gnu.org> --- (In reply to Iain Buclaw from comment #4) > Looking at gcc/builtins.cc, I have a bad feeling that the only compile-time > /* If it isn't always lock free, don't generate a result. */ > if (fold_builtin_atomic_always_lock_free (arg0, arg1) == boolean_true_node) > return boolean_true_node; ^ but this does fall back to a libcall to the relevant libatomic function, (you can verify that with a simple C routine).. and given that both darwin and linux powerpc have libatomic impls. this still should not give an "unimplemented" response.
