On Fri 01/10/10 06:52 , Mark Engelberg mark.engelb...@gmail.com sent: > On Thu, Sep 30, 2010 at 9:13 PM, ataggart agg...@gmail.com> wrote:> As with > most microbenchmarks you're measuring > the test more than the> subject. In the above case the seq > generation dominates.> > > Compare the following on my machine: > > user=> (time (doseq [x (range 100000)] > (bit-shift-left x 1)))> "Elapsed time: 3531.198 > msecs"> nil > > user=> (time (dotimes [x 100000] > (bit-shift-left x 1)))> "Elapsed time: 3.744 msecs" > > nil > > But if you replace the bit-shift-left operation with some other > arithmetic operation in the doseq expression, it is quite fast, thus > disproving your assertion that the slowdown is caused by the overhead > of doseq. Furthermore, as we've already discussed, type hinting the x > or removing the inline delcaration from bit-shift-left makes the > problem go away -- inside the doseq expression. > > So, if it is true that range produces objects and dotimes produces > primitive longs, then I believe that it is the odd interaction between > bit-shift-left's inlining and long objects (as opposed to primitives) > that is causing the disparity in your measurements, not something > inherent in the mechanism of doseq vs dotimes. > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to cloj > u...@googlegroups.comnote 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.comfor more options, visit this group at > > http://groups.google.com/group/clojure?hl=en > >
-- 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
