In general, any benchmark code using math should be aware of boxing (old post here: http://insideclojure.org/2014/12/15/warn-on-boxed/).
I would recommend doing the work to leverage primitive longs and unchecked math. Generally this makes numeric code like this about 2 orders of magnitude faster. Removing the stateful atom and converting to a purely functional form would probably be a win too, but it's hard to say. Make sure to run it multiple times before looking at timings so that the JVM compiles and optimizes the code. On Tuesday, November 15, 2016 at 9:39:43 PM UTC-6, Didier wrote: > > Hey all, > > I came upon a benchmark of F#, Rust and OCaml, where F# performs much > faster then the other two. I decided for fun to try and port it to Clojure > to see how Clojure does. Benchmark link: > https://github.com/c-cube/hashset_benchs > > This is my code for it: > https://gist.github.com/didibus/1fd4c00b69d927745fbce3dcd7ca461a > > (ns hash-set-bench > "A Benchmark I modified to Clojure from: > https://github.com/c-cube/hashset_benchs";) > > (defn iterNeighbors [f [i j]] > (f [(dec i) j]) > (f [(inc i) j]) > (f [i (dec j)]) > (f [i (inc j)])) > > (defn nth* [n p] > (loop [n n s1 #{p} s2 #{}] > (if (= n 0) > s1 > (let [s0 (atom #{})] > (letfn [(add [p] > (when (not (or (contains? s1 p) (contains? s2 p))) > (reset! s0 (conj @s0 p))))] > (doseq [p s1] (iterNeighbors add p)) > (recur (dec n) @s0 s1)))))) > > #_(printf "result is %d" (count (time (nth* 2000 [0 0])))) > > And here's the F# code: > https://github.com/c-cube/hashset_benchs/blob/master/neighbors2.fsx > > Currently, this takes about 30s in Clojure, while it only takes around 3s > for OCaml, Rust and F#. > > From what I see, the differences between my code and theirs are: > > - Lack of a Point struct, I'm just using a vector. > - They use a mutable set, I don't. > - They overrode Hashing for their point struct, as well as equality. I > rely on Clojure's default hashing, and vector equality. > > I'm not sure if any of these things should really impact performance that > much though. And what I could do in Clojure if I wanted to improve it. > > > Any Help? > > > Thanks. > -- 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/d/optout.
