Question of Mathematical Foundation of Data Science

As part of a computer application, a sub-routine needs to be written, whose input parameter 񑝠has to be used in the computation 񐴽ѝ where 񐴠is a 100×100 symmetric, positive-definite matrix 񐴮 Note that 񐴠is a fixed matrix, and it is only 񑝠which is the input parameter. What is the most efficient way you can come up with to perform the required computation, if the sub-routine is called millions of times for arbitrary values of 񑝿 Your solution needs to be efficient in terms of both time and space taken by the algorithm.