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[Caml-list] looping recursion
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| Date: | -- (:) |
| From: | Xavier Leroy <Xavier.Leroy@i...> |
| Subject: | Re: [Caml-list] looping recursion |
> > Lemme try it out (10^6 elements): > > > > ocamlc: > > rev rev_map version: > > 2 WALL ( 1.19 usr + 0.02 sys = 1.21 CPU) > > vanilla map: > > 7 WALL ( 6.50 usr + 0.09 sys = 6.59 CPU) > > > > ocamlopt: > > rev rev_map version: > > 1 WALL ( 0.81 usr + 0.03 sys = 0.84 CPU) > > vanilla map: > > 2 WALL ( 2.45 usr + 0.02 sys = 2.47 CPU) > > OK, so why is List.map in the OCaml standard library implemented the > vanilla way rather than the rev rev_map way? If it's such a big win, > it seems foolish to have a broken implementation for such a crucial > function. Because for smaller list the "vanilla way" is more efficient. In the test above, the vanilla way spends significant time resizing the stack. I suspect that when running it a second time on a already resized stack, the timings would improve quite a lot. - Xavier Leroy ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners