Apple Inc.
Floating-point division alternative techniques

Abstract:

Techniques are disclosed relating to circuitry configured to perform reciprocal-based floating-point division. In some embodiments, floating-point circuitry includes reciprocal circuitry configured to generate a reciprocal of a divisor, multiplication circuitry configured to multiply the reciprocal results with a dividend, and circuitry configured to clear a least significant bit of an integer representation of the multiplication output to generate a modified multiplication output. The floating-point circuitry may be configured to convert the modified multiplication output to a representation using the first precision to generate a division output. In some embodiments, the refinement using the integer representation may provide correctly-rounded subnormal division results. The disclosed techniques may improve accuracy, reduce processing time, and/or reduce instructions needed for floating-point division, with little to no increase in chip area.