Optimization of Lookup Table Size in Table-Bound Design of Function Computation

Computation of function values is critical for designing datapath units in digital signal processors (DSP) and graphics processing units (GPU). Most function computation methods requires lookup tables (LUT) and simple arithmetic components. In table-bound methods, LUT size takes a significant portion of total hardware area, in particular for high-precision applications. This paper presents a new multi-level lossless table decomposition to further reduce total table size in a recently proposed hierarchical multipartite (HMP) table method which is a generation of the prior bipartite/multipartite table-addition methods. Furthermore, hardware design parameters are optimized by jointly considering all the error sources. Experimental results shows that the proposed design has the chance of further reducing the total table size of HMP, which already has significant table-size saving over previous similar designs.