CPUs have many different configuration bits to configure floating point rounding, flushing denormals, etc. which mean that in practice anything that relies on floats being deterministic has the stability of a house of cards.

> Floating point is deterministic, what are you talking about?

Order of operations can change a result, for example. I suspect you mean that the algorithm never changes. While op means that mathematical operations which most folks would expect to be reliable are not.