https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83730
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- As I noted at https://gcc.gnu.org/ml/gcc-help/2019-10/msg00038.html the guard variable is emitted, but appears to be unused when compiled with -fno-threadsafe-statics.
