Floating Point Modulo Operation

Question

I am trying to implement the range reduction operation for trigonometry. But instead I think it might be better to just perform a modulo pi/2 operation on incoming data. I

Answer 1

Exact fmod is implemented with long division. The exact remainder is always representable as the dividend and the divisor share the same format. You can look into open-source implementations like glibc and musl. I have also made one in metallic. (shameless plug)

Payne–Hanek range reduction is for constant divisors like π, whose reciprocal we store in advance. Hence, it is not applicable here.