I wrote a comment in the gist. 2014-12-11 17:08 GMT-05:00 Robert Gates <[email protected]>:
> In any case, this does make me wonder what is going on under the hood... I > would not call the vectorized code "vectorized". IMHO, this should just > pass to BLAS without overhead. Something appears to be creating a bunch of > temporaries. > > On Thursday, December 11, 2014 5:47:01 PM UTC+1, Petr Krysl wrote: > >> Acting upon the advice that replacing matrix-matrix multiplications in >> vectorized form with loops would help with performance, I chopped out a >> piece of code from my finite element solver (https://gist.github.com/ >> anonymous/4ec426096c02faa4354d) and ran some tests with the following >> results: >> >> Vectorized code: >> elapsed time: 0.326802682 seconds (134490340 bytes allocated, 17.06% gc >> time) >> >> Loops code: >> elapsed time: 4.681451441 seconds (997454276 bytes allocated, 9.05% gc >> time) >> >> SLOWER and using MORE memory?! >> >> I must be doing something terribly wrong. >> >> Petr >> >>
