2009/11/15 ajuc <aju...@gmail.com>: > >> That's very odd. >> >> Rich needs to take a look at this. Letting a constant shouldn't have a >> performance hit, IMO. >> >> Could you test whether it's faster to use your complex data structure >> directly in the function, anonymously at the point of use, or to yank it >> from a global var? > > Code (can you run it on your computer to verify?): > http://clojure.pastebin.com/f508ad31b
Here are my results on Linux with the server VM, after fixing the typo (glocal -> global) and changing pr to println: http://clojure.pastebin.com/f49f16d71 "Elapsed time: 2110.721659 msecs" point-to-hilbert-directly-from-global nil "Elapsed time: 1197.547328 msecs" point-to-hilbert-let-from-global nil "Elapsed time: 1884.777766 msecs" point-to-hilbert-literal-in-let nil "Elapsed time: 4847.630084 msecs" point-to-hilbert-literal-in-place nil $ java -version java version "1.6.0_0" OpenJDK Runtime Environment (IcedTea6 1.4.1) (6b14-1.4.1-0ubuntu12) OpenJDK Client VM (build 14.0-b08, mixed mode, sharing) Although, running it again now, I get: "Elapsed time: 3278.709938 msecs" point-to-hilbert-directly-from-global nil "Elapsed time: 1234.739782 msecs" point-to-hilbert-let-from-global nil "Elapsed time: 1945.980422 msecs" point-to-hilbert-literal-in-let nil "Elapsed time: 5737.756701 msecs" point-to-hilbert-literal-in-place nil And after rearranging them, I get: "Elapsed time: 2506.30872 msecs" point-to-hilbert-let-from-global nil "Elapsed time: 2091.866122 msecs" point-to-hilbert-literal-in-let nil "Elapsed time: 1309.805767 msecs" point-to-hilbert-directly-from-global nil "Elapsed time: 5228.071194 msecs" point-to-hilbert-literal-in-place nil So it seems you need to allow Hotspot to optimise it: "Elapsed time: 3084.796868 msecs" point-to-hilbert-literal-in-let nil "Elapsed time: 1354.13218 msecs" point-to-hilbert-literal-in-let nil "Elapsed time: 1340.907318 msecs" point-to-hilbert-literal-in-let nil "Elapsed time: 1338.655641 msecs" point-to-hilbert-literal-in-let nil and: "Elapsed time: 2393.682633 msecs" point-to-hilbert-let-from-global nil "Elapsed time: 990.713252 msecs" point-to-hilbert-let-from-global nil "Elapsed time: 1008.451391 msecs" point-to-hilbert-let-from-global nil "Elapsed time: 985.379787 msecs" point-to-hilbert-let-from-global nil -- Michael Wood <esiot...@gmail.com> -- 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
