Stefan, please consider the updated version https://gist.github.com/PetrKryslUCSD/7bd14515e1a853275923
which has no global variables. 2014-12-12 10:07 GMT-05:00 Stefan Karpinski <ste...@karpinski.org>: > From the original version of the code I see this timing after code gen: > > julia> @time Ke1(N); > elapsed time: 0.251365495 seconds (134400208 bytes allocated, 30.13% gc > time) > > julia> @time Ke2(N); > elapsed time: 3.923532621 seconds (996800384 bytes allocated, 13.97% gc > time) > > After making all the globals const, I see this: > > julia> @time Ke1(N); > elapsed time: 0.273683599 seconds (131200208 bytes allocated, 28.52% gc > time) > > julia> @time Ke2(N); > elapsed time: 0.026985097 seconds (384 bytes allocated) > > Type annotations everywhere are neither necessary nor recommended. It is > recommended not to use lots of non-constant globals. > > > On Fri, Dec 12, 2014 at 9:36 AM, Tim Holy <tim.h...@gmail.com> wrote: > >> On Thursday, December 11, 2014 08:10:38 PM Petr Krysl wrote: >> > The moral of this story is: If you can't or won't declare every single >> > variable, don't do loops. They are likely to be a losing proposition. >> >> Just to follow up further, this is not at all the right moral to absorb >> from >> this. A better set of morals is: >> - use code_typed or TypeCheck or Lint to diagnose problems >> - remember that julia optimizes functions as a unit. Therefore, in a loop >> with >> a type issue, one "brute force" solution is to create a separate function >> just >> for running that loop. The types will be known when that function gets >> compiled (even if you don't annotate anything with their types), and so >> your >> type problem should evaporate. >> >> --Tim >> >> >
