https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113578
--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> --- Hmm, you could be right. It looks like the printf in Apple libc doesn't print "-nan" even when not converting from float to double. According to https://developer.r-project.org/Blog/content/post/2020-11-02-apple-silicon.html the Apple silicon NaN payloads are not propagated by default, but I don't know if that means the signbit is not propagated. I assumed it meant they were running in default NaN mode.
