Floating Point Tangent Implementation for FPGAs

This paper presents an implementation of the floating-point (FP) tangent function, optimized for an FPGA containing hard floating point (HFP) DSP Blocks. This function inputs values in the interval [-π/2,π/2], uses the IEEE-754 single-precision (SP) format, and has an accuracy conforming to OpenCL requirements. The presented architecture is based on a combination of mathematical identities and properties of the tangent function in FP. The resultant design outperforms generic polynomial approximation methods targeting the same resource utilization spectrum, and provides better resource trade-offs than classical CORDIC-based implementations. The presented work is widely available as part of the Intel DSP Builder Advanced Blockset.