Calculation of trigonometric functions in an integrated circuit device

A method of configuring a programmable integrated circuit device as circuitry for computing on x and y datapaths a trigonometric function of an input on a z datapath, said method comprising:

• configuring logic of said programmable integrated circuit device as a comparison element to determine that said input is at or above a threshold, or below said threshold;
• configuring logic of said programmable integrated circuit device as a first left-shifter for shifting said z datapath by a constant when said input is below said threshold;
• configuring logic of said programmable integrated circuit device as a second left-shifter for shifting an initialization value of said x datapath when said input is below said threshold;
• configuring memory of said programmable integrated circuit device as 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
• configuring logic of said programmable integrated circuit device as 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.

A non-transitory machine-readable data storage medium encoded with machine-executable instructions for configuring a programmable integrated circuit device as circuitry for computing on x and y datapaths a trigonometric function of an input on a z datapath, said instructions comprising:

• instructions to configure logic of said programmable integrated circuit device as a comparison element to determine that said input is at or above a threshold, or below said threshold;
• instructions to configure logic of said programmable integrated circuit device as a first left-shifter for shifting said z datapath by a constant when said input is below said threshold;
• instructions to configure logic of said programmable integrated circuit device as a second left-shifter for shifting an initialization value of said x datapath when said input is below said threshold;
• instructions to configure memory of said programmable integrated circuit device as 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
• instructions to configure logic of said programmable integrated circuit device as 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.