Hello, I tried to inline everything in the main loop (the updaters loops) and obtained on my machine a 15% speed-up.
One of the possible slowdown may come from having arrays and not object. Maybe, each access need to perform a size check on the array. Which is not very costly but not negligible when you have very few operations on each elements. I read Hot Spot removes checks when it can decide they are useless. But it is not clear in this program they are useless. (You take an array in a structure in each iteration and access fields from 0 to 6. If the size is not known then it has to test acces for 1, then 2, then 3...) Maybe you could try each time you take a [b (bodies i)] to check that it's size is at least 7. If Hot Spot is clever enough it would reduce the number of checks. I am not sure it would do much good though, but I would like to know. Else, you could try to put everything in one big array, and replace bodies by their index. I wonder whether there would be a speed-up or not from removing indirections. Best, Nicolas. On Wed, 2009-08-12 at 00:26 -0400, Aaron Cohen wrote: > On Tue, Aug 11, 2009 at 8:13 PM, Andy > Fingerhut<andy_finger...@alum.wustl.edu> wrote: > > > > On Aug 11, 2:36 pm, Aaron Cohen <remled...@gmail.com> wrote: > >> At that point is it possible you're just paying the price of > >> PersistentVector for the "bodies" vector? Does it improve much if you > >> change bodies to an array? > > > > About 7% faster changing bodies to a Java array of java.lang.Object's, > > each of which happens to be a Java array of primitive doubles, as > > before. Now about 3.0 x Java run time. > > > > http://github.com/jafingerhut/clojure-benchmarks/blob/43ed2f42e6c1485541532e51eacc66488949c658/RESULTS > > > > I'm actually glad that the difference is that small there. > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
