One thing that’s causing me second thoughts on the “should minnum respect signed zero by default” question is that signed zero ordering isn’t mandated not just by IEEE 754-2008, but also by Annex F of the C standard (it’s only an “if possible” footnote), and we want minnum to be lowerable to an fmin libcall. We can’t guarantee that the fmin lowering will follow the stricter signed zero semantics based on just the standard. Is it safe to assume that in practice, all libc’s do implement signed zero ordering?