Abstract: The basic mathematical function library is a critical soft module in the computer system.However,the long vector transcendental function on the domestic Shenwei platform can only be implemented indirectly by cyclic utilizing the system scalar function currently,thus limiting the computing capability of the SIMD extensions of Shenwei platform.In order to solve this problem effectively,this paper implements the long vector transcendental function based on lower-level optimization of SIMD extensions of Shenwei platform and proposes the floating-point computing fusion algorithm for solving the problem that the two-branch structure algorithm is difficult to vectorize.It also proposes the implementation method of higher degree polynomials based on the dynamic grouping of Estrin algorithm,which improves the pipelining performance of polynomial assembly evaluation.This is the first time to implement the long vector transcendental function library on the Shenwei platform.The providedfunction interfaces include trigonometric functions,inverse trigonometric functions,logarithmic functions,exponential functions,etc.The experimental result shows that the maximum error of double precision version is controlled below 3.5ULP (unit in the last place),and the maximum error of single precision version is controlled below 0.5ULP.Compared with the scalar function of Shenwei platform,the performance is significantly improved,and the average speedup ratio is 3.71.

Key words: Basic mathematic library, Domestic platform, Floating point calculation, Pipeline optimization, Vector transcendental function