About counting flops for matrix multiplication

How can I count flops for matrix multiplication? Should I use timing function or others?

Thank you!

Answer 1

[the cyclist]

This function from the File Exchange claims to do this. (I've never used it, so I cannot vouch for it.)

[Walter Roberson]

Writing that took some dedication!

Note to Bo Wang: You cannot count flops by timing on any modern system. It has been effectively impossible since the first RISC CPU came out, if not earlier. And that was decades ago, the Sun SPARC or earlier. 1981 is sometimes given as the date after which flops became meaningless.