It looks like an improvement in clojure.lang.BigInt over java.math.BigInteger - BigInt's add() method seems to do a long + long add if it doesn't overflow (https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/BigInt.java#L142) and only fall back to BigInteger's add method (which has no such optimisation - http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/math/BigInteger.java#BigInteger.add%28java.math.BigInteger%29) if the overhead of BigInteger is actually needed.
If you use clojure.lang.BigInt in your Java code, I suspect Java will be faster. On 25 February 2014 10:38, Jonathan Barnard <jonathan.t.barn...@gmail.com> wrote: > I recently did a benchmark (admittedly in hindsight not a particularly good > one) that involved comparison of an implementation of the same small program > in Java and in Clojure, in which most of the time is spent in bignum > operations. The results are at this link (the tables at the top; ignore the > rest). The Clojure implementation appears to consistently perform better > than the Java implementation (at least on this setup, x86-64 Linux with > OpenJDK 1.7.0_25). I'd be interested to learn what Clojure does to make it > perform faster than Java in this case, so I thought here might be a good > place to ask. > > -- > 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. -- Robert K. Day robert....@merton.oxon.org -- 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.
