Right; the range reduction from [-pi;pi] would be like 5 instrs ("x -= copysign(pi/2 & (abs(x)>pi/2), x)" or so), ~2 cycles throughput-wise or so, I think; that's slightly more significant than I was imagining, hmm.
It's indeed not a substitute for sin in general, but it could be in some use-cases, and for those it could really be 40x faster (say, cases where you're already externally doing range reduction because it's necessary for some other reason (in general you don't want your angles infinitely accumulating scale)).
It's indeed not a substitute for sin in general, but it could be in some use-cases, and for those it could really be 40x faster (say, cases where you're already externally doing range reduction because it's necessary for some other reason (in general you don't want your angles infinitely accumulating scale)).