Based on a proposal by @gjlayde on https://www.mikrocontroller.net/topic/85256#6137882, speed of fp64_sin could be improved by another 45%, using an optimized polynomial approximation for x in range [0,PI/2[.
Handcrafted 64-bit floating point routines for AVR/arduino microprocessors
Based on a proposal by @gjlayde on https://www.mikrocontroller.net/topic/85256#6137882, speed of fp64_sin could be improved by another 45%, using an optimized polynomial approximation for x in range [0,PI/2[.