Patent ID: 8510354

Claim:
Circuitry for computing on x and y datapaths a trigonometric function of an input on a z datapath, said circuitry comprising: a comparison element to determine that said input is at or above a threshold, or below said threshold; a first left-shifter for shifting said z datapath by a constant when said input is below said threshold; a second left-shifter for shifting an initialization value of said x datapath when said input is below said threshold; a look-up table including inverse tangent values based on negative powers of 2, and based on negative powers of 2-plus-said-constant and shifted by said constant, for adding to/subtracting from said z datapath; and shifters for right-shifting elements of said x and y datapaths by amounts incorporating said constant and respective predetermined shift amounts that are adjusted when said input is below said threshold.