Thank you for the pointer to unchecked-remainder. That runs much better. -B
On May 3, 6:23 pm, kaukeb <kau...@gmail.com> wrote: > Using unchecked-remainder and adding a type declaration to the last > constant keeps the primitives unboxed and improves performance by a > factor of 6 for me. I couldn't say whether there's a reason rem and > mod don't work like you'd expect here. > > (defn NF-mod-limit [p q limit] > (let [p (long p) q (long q) limit (long limit)] > (loop [n (long 0), nf (long 0), z (long 0), S (long 290797)] > (if (= n (inc q)) > nf > (recur > (inc n) > (unchecked-remainder > (+ nf (* (unchecked-remainder S p) z)) > limit) > (unchecked-remainder (inc (* p z)) limit) > (unchecked-remainder (* S S) (long 50515093))))))) > > On May 3, 1:21 pm, Brian Watkins <wildu...@gmail.com> wrote: > > > > > Any ideas about this? > > > On May 2, 1:44 am, Brian Watkins <wildu...@gmail.com> wrote: > > > > I'm trying to speed up computing terms of a simple recurrence where > > > the terms are computed modulo some value each iteration, > > > > (defn NF-mod-limit [p q limit] > > > (loop [n 0, nf 0, z 0, S 290797] > > > (if (= n (inc q)) nf > > > (recur (inc n) > > > (mod (+ nf (* (mod S p) z)) limit) > > > (mod (inc (* p z)) limit) > > > (mod (* S S) 50515093)))))) > > > > So I added in some type hinting, > > > > (defn NF-mod-limit [p q limit] > > > (let [p (long p) q (long q) limit (long limit)] > > > (loop [n (long 0), nf (long 0), z (long 0), S (long 290797)] > > > (if (= n (inc q)) nf > > > (recur (inc n) > > > (long (mod (+ nf (* (long (mod S p)) z)) limit)) > > > (long (mod (inc (* p z)) limit)) > > > (long (mod (* S S) 50515093))))))) > > > > But it doesn't run any faster. Also it doesn't work without casting > > > to long within the recur. Is that maybe a problem with mod and > > > primitive arithmetic or does this simply not speed up any more in > > > Clojure? > > > > -- > > > 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 > > > athttp://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 > > athttp://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 > athttp://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
