[jacobolus]

My understanding is that most software always uses some software implementation of sine, rather than calling a hardware instruction. Which is definitely what you should do if you care about getting the exact same results across platforms.

[dzaima]

Software implementations can and do differ (even dynamically) based on the hardware though - e.g. glibc's sin(x) function, what C code will end up using (if not other languages relying on the C stdlib), uses FMA instructions on my CPU, and thus the exact same binary on the exact same OS with the exact same glibc should behave differently on a very old CPU without FMA where it should have a different implementation (as generally things using FMA cannot be exactly ported to hardware without it without a gigantic drop in performance which'd be extremely unacceptable).

[jacobolus]

Yeah, the lack of FMA in some contexts is a serious bummer. It would be great if every popular CPU platform would figure out a way to get FMA implemented, and if programming languages would figure out better ways to help programmers use it explicitly without making their code too ugly.

[adgjlsfhk1]

at this point, Intel, AMD, Arm, and RiscV all do and have for a while. The only one that is at all relevant that doesn't is Apple m-series under rosetta.