Fused floating-point two-term sum-of-squares unit

This paper proposes a low-power and high-performance fused floating-point two-term sum-of-squares (fused SoSQ) unit and compares it with discrete and fused dot-product units containing normal significand multipliers and discrete sum-of-squares units containing significand squarers; with these units, sum-of-squares is computed. The fused sum-of-squares unit has less latency, area, and power consumption than the floating-point dot-product units and the discrete parallel sum-of-squares unit. The main reason is that a fused floating-point architecture is used, its significand squarer is faster and smaller than normal significand multipliers, and the sub-modules related to subtraction can be removed. Furthermore, compound addition can be applied to the fused sum-of-squares unit to enhance the performance in the single-path addition. Compared with the fused floating-point dot-product, the fused floating-point sum-of-squares unit with the compound addition has 54% less power consumption, 48% less area, and 44% less latency.