[signa11]

indeed. riscv for instance. also, afaik, xor’ing is faster. i would assume that someone like mr. raymond would know…

[IshKebab]

> afaik, xor’ing is faster

Even tiny tiny CPUs can do sub in one cycle, so I doubt that. On super-scalar CPUs xor and sub are normally issued to the same execution units so it wouldn't make a difference there either.

[tliltocatl]

On superscalars running xor trick as is would be significantly slower because it implies a data dependency where there isn't one. But all OOO x86's optimize it away internally.

[IshKebab]

Sub has the same false data dependency.

[pif]

Which part of "mathematical operations don’t reset the NaT bit" did you not understand?