Catching hardware / arithmetics errors

[Tino]

Slightly related:

Comparable and FloatingPoint types

Even if you could interact with them in Swift, that would give worse performance on every existing architecture; reading and modifying these registers is generally a "stop the world" serializing operation, while testing for NaN with comparison is just another floating-point operation. In a model where there were no "normal" floating-point operations, you could simply enable the invalid trap ("unmask the floating-point exception"), but you'd still need to toggle it at any call that could potent…