Acceleration of Multiple Precision Matrix Multiplication using Ozaki scheme

Optimized multiple precision basic linear computation, especially matrix multiplication, is crucial for solving ill-conditioned problems. The recently proposed Ozaki scheme, which implements accurate matrix multiplication using existing optimized low precision matrix multiplication, is known to be useful for multiple precision as well. In this paper, we implement fixed precision multi-component-way matrix multiplication using Ozaki scheme and show that in some cases it is faster than existing optimized matrix multiplications. We also show that arbitrary precision matrix multiplication using Ozaki scheme is also faster than Strassen matrix multiplication up to a certain precision.