Improvement of error-free splitting for accurate matrix multiplication

Abstract Recently, new algorithms for accurate matrix multiplication have been developed by the authors. A characteristic of the algorithms is a high dependency on level-3 BLAS routines, which are highly optimized for several architectures. An error-free splitting for floating-point matrices is a key technique in the algorithms. In this paper, an improvement of the error-free splitting is focused on. It is shown by numerical examples that the accuracy of computed results of matrix products can be improved by the modified error-free splitting, compared to that by the previous algorithms.