Some (a lot?) of those got cleaned up in the 2008 revision [1]. And for many practical purposes, once x87 went away as part of x86-64, we now have a world of much more sensible agreement.

We're likely coming back into a period of divergence with ARM vs x86 parts on edge case handling that aren't strictly stated as MUST in the standard (various things related to qNaNs, sNaNs, denormal handling, +-0) but they're minor compared to the "old days".

[1] https://en.m.wikipedia.org/wiki/IEEE_754-2008_revision