Does matlab 2012a auto vactorize?

I recently had 2012a installed at work. I had previously had 2010. I noticed a surprising performance improvement in code that contained for loops, that had not been vectorized. Several people at work noticed this causing us to speculate that matlab contained an internal vectorized version of "for".

Can anyone shed light on this? Thanks.

Answer 1

[Walter Roberson]

Yes, between those two releases, MATLAB did make a significant optimization improvements. One of the significant improvements was that MATLAB now automatically predicts preallocation requirements, saving significant time in memory management if the programmer had not put in preallocation.

Answer 2

[David Bergman]

Walter, thanks. Do you know of any documentation on this? It makes me wonder if it's even worth learning to vectorize ;-). Once you get good at it, it makes you thinks differently about how to structure and write code. Many young engineers are educated on matlab and never learn C/C++ or FORTRAN. If one writes C-style code in matlab can you expect it to run just as fast as C? Thanks again.

[Star Strider]

For documentation, I refer you to ‘Release Notes’: http://www.mathworks.com/help/techdoc/rn/rn_intro.html.

For the rest I refer you to Walter Roberson.