Also, neither roundevenf (in the case of line 629) nor roundeven (line 630) appear to work for my use case, NetBSD/i386. So if that is all that the fallback currently does, at least on NetBSD it is usable only on amd64, not i386, and maybe not on other 32 bit platforms either.
Which is why I asked in my first post if the choice is between replacing roundeven(f) with f32 or f64_roundeven at the risk of breaking amd64, or a 32 bit only fallback that does NOT touch 64 bit ever.
