Low Cost Design for Elementary Function Approximation Based on Piecewise Quadratic Interpolation
Tao Niu, Haibin Shen · Jisuanji gongcheng · 2013
A low cost design for elementary function approximation based on piecewise quadratic interpolation to support singleprecision floating-point data,that can be able to complete the approximation to the reciprocal,squarer root,squarer root reciprocal,exponential,trigonometric and other elementary functions is presented.The traditional computation of quadratic polynomial needs one squarer,two multiplications and three additions.But this design only needs two Multiply And Accumulate(MAC) operations by the deformation of quadratic polynomial,and can complete the computation by reusing the MAC architecture.In the result,the design can reduce 56% of the computing area and save 17.5% cost of hardware in total,though the entire approximation operation takes two clock cycles to complete.