On Aug 10, 11:35 am, fft1976 <fft1...@gmail.com> wrote: > On Aug 10, 4:46 am, Jarkko Oranen <chous...@gmail.com> wrote: > > > I'm not going to start optimising, > > Somebody'd better! > > You always hear this dogma that one should write "elegant" code first > and optimize later, and when you do that, a few little changes can > make Clojure as fast as Java. > > Here's your chance to show it :-) > > > but somehow I doubt that is > > the bottleneck > > The locality of changes is what I doubt.
I've got a functional version in my clojure-benchmarks git repository, too, and it is currently 138 times slower on my machine than the Java version. I haven't looked in detail at your code, but at a high level it appears to be similar to yours in structure -- i.e., it doesn't try to go overboard with float/double declarations, and uses only Clojure data structures. I haven't tried optimizing it yet, just because I've done more optimizing with some of the other benchmarks first. It would be nice to have a Clojure version under 10 times Java's run time here, without resorting to Java data structures and methods. There may be better motivational techniques than using the word "dogma" and daring people to do better :-) Then again, perhaps this may be an example where the best thing for someone working on a real project is to take the inner loop code and write it in Java, the way some people take inner loops in C progams and hand-code them in assembly -- because they are in a situation where it is worth the time to optimize. I would point out that some of these benchmark programs in Haskell, for example, are not pure functional implementations, and people have gone to (what seems to me) great effort to optimize the heck out of their programs in ways that most Haskell programmers would probably find excessive. Even some of the C and C++ implementations seem to pull out __builtin_memmove calls and explicitly using SSE macros in order to tweak out a few more milliseconds of lower run time. Andy --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
