Mitchell-Based Approximate Operations on Floating-Point Numbers

Abstract: By adapting Mitchell's algorithm for floating-point numbers, one can efficiently perform arithmetic floating-point operations in an approximate logarithmic domain in order to perform approximate computations of functions such as multiplication, division, square root and others. This work examines how this algorithm can be improved in terms of accuracy and hardware complexity by applying a set of various methods that are parametrized and offer a large design space. Optimal coefficients for a large portion of this space is determined and used to synthesize circuits for both ASIC and FPGA circuits using the bfloat16 format\@. Optimal configurations are then extracted to create an optimal curve where one can select an acceptable error range and obtain a circuit with a minimal hardware cost.