At least in my limited experience, matrix multiplication optimization is some combination of a) so specific to the specific matrices being used that the optimiz

At least in my limited experience, matrix multiplication optimization is some combination of a) so specific to the specific matrices being used that the optimization amounts to finding "tricks" to reduce the problem (dgemm to sgemm or sgemm to syrk, etc.) and thus is not generally useful or b) so highly tied to IP that general optimizations (be they mathematical or advances in GPU or CPU low-level code) are kept secret.