How can I make my matlab code fast?

I have tried to find the dot product of two matrices but the code takes approximately 12 minutes to compute which is huge amount of time. I asked the question on stackoverflow but didn't find any solution to the problem. Kindly help in recognising what can be done to reduce the time. It will be more helpful if you can modify the code so as to get an efficient code.

Here is the link to the code

http://stackoverflow.com/questions/42833375/why-is-mex-code-much-slower-than-the-matlab-code/42840498?noredirect=1#comment72795989_42840498

[Adam]

If you are already getting help over in the stackoverflow forum it doesn't really make sense to start another conversation here where people may make the same points or want to discuss points which are in the other forum.

[Navdeep Sony]

It is not necessary that everyone will have the same opinion. Some one may come up with a really good solution. Another thing is that you can actually see the link and you will find that no one talked about the solution. So not to talk here about something which is shared somewhere else and not yet answered does not make sense.

[John D'Errico]

Your question is not in fact about MATLAB at all, but in how to make your compiled C code as fast as MATLAB. As far as making a MATLAB computed dot product faster, you won't do that too easily, as if they could find a way to make such basic operations faster, they already would have done so. Certainly you will not find much of a boost.