Here is the mundane patch I described earlier: https://github.com/cgrand/clojure/commit/4c202ad9757ce47ac9e669847c0e5bf68785e2d6
It adds four functions (add-, multiply-, divide- and subtract-float), backs them with their corresponding bytecodes and enhance the conversion emitted when going from long/int to double/float. Please give it a try. It doesn't help with functions taking primitive but it's another problem. Christophe On Mon, Sep 16, 2013 at 7:03 PM, James Reeves <ja...@booleanknot.com> wrote: > > > > On 16 September 2013 09:03, Mikera <mike.r.anderson...@gmail.com> wrote: > >> >> Obviously this is just a microbenchmark, but it fits my general >> experience that floats are a reasonable bit faster than doubles, typically >> 20-100% (doubles are closer when it is pure number crunching since 64-bit >> CPUs are actually pretty good at doubles, floats have a bigger advantage >> when you are manipulating a lot of data points and hence memory bandwidth >> matters more) >> >> Code here for those interested: >> src/test/java/mikera/vectorz/performance/FloatVsDoubleBenchmark.java >> > > That's a pretty interesting result. I ran some tests of my own, based on > your code, as I wondered whether or not the time to instantiate the array > of doubles was biasing the test. My goal was to see whether or not I'd get > a similar result running an array of floats through a method that processed > doubles. (See: https://gist.github.com/weavejester/6583367) > > It turns out that I get a similar result. Passing floats to a method that > takes doubles slows things down by a similar amount, unless I've somehow > botched up the test. Considering that converting between single and double > precision should be pretty cheap on the CPU, I'm surprised at the > difference. > > This somewhat changes my view on things. It doesn't affect me in practice, > but I can see how someone might be frustrated by having to drop down to > Java to achieve performance for floating point calculations. > > - James > > -- > -- > 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 > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > -- On Clojure http://clj-me.cgrand.net/ Clojure Programming http://clojurebook.com Training, Consulting & Contracting http://lambdanext.eu/ -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
