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Date: -- (:)
From: Mattias Waldau <mattias.waldau@a...>
Subject: OCaml is fast!
or is my benchmark wrong? The speed is incredable, I have a 333 Mhz PII, and
Ocaml make 50 miljon round trips in the loop per second, that is 6 cycles
per loop, and in each loop one function call + add + store is done.

Or does the compiler optimize away a lot of my code? The code can be found
in the end of the file.

I made the benchmark to compare object creation + method call versus term
creation + function call. Object creation is 10 times slower, and method
calls 5 times slower. However, this difference will not be noted in a real
program unless you use objects for the smallest and most primitive objects,
like nodes in a tree and similar.

As always, I am impressed by the speed of Ocaml. However, a small superflous
';' was difficult to find, since the compiler always complained about syntax
error on the last line in the file.

----
Mattias Waldau, CTO
Tacton AB, Saltmatargatan 7, 11359 Stockholm
Mobile +46 70 549 11 12
http://www.tacton.com mailto:mattias.waldau@tacton.com


P.s. I got a tip on how to let the top level print the contents of objects -
something I complained about earlier - just define a print-method and use
#install_printer, se below

method print ff =
  Format.fprintf ff "@[with_oo:(x=%i; y=%i)@]" x y

and install it by

# let object_printer x = x #print Format.std_formatter;;
# #install_printer object_printer


(* benchmark ---------------------------------------- *)


(*
   ocamlopt.exe unix.cmxa oo_test.ml


100 000 000 loops,

2 miljons object creations + method call per second
10 miljons method calls per second

25 miljons term creations + method call per second
50 miljons function calls per second


oo with create: Run time = 51
method call only: Run time = 9
create term and call function: Run time = 4
call function: Run time = 2

*)


class with_oo =
object
  val mutable x = 0
  val mutable y = 0
  method get_x = x
  method move d = x <- x + d; y <- y + d
  method print ff =
    Format.fprintf ff "@[with_oo:(x=%i; y=%i)@]" x y
end

(*
let object_printer x = x #print Format.std_formatter;;
#install_printer object_printer
*)

let test_oo_speed () =
  for ii = 1 to 100000000 do
    (new with_oo)#move ii;
  done

let test_oo_speed_2 () =
  let obj = new with_oo in
  for ii = 1 to 100000000 do
    obj#move ii;
  done

(*
   Format.fprintf gor verkligen magiska saker, skapar functioner
   som tar olika manga argument beroende pa strangen. Men det ar
   kanske inte sa svart, eftersom de ar curried. Borde testa!!

# Format.fprintf Format.std_formatter "@[with_oo:(x=%i; y=%i)@]";;
with_oo:(x=- : int -> int -> unit = <fun>
# Format.fprintf Format.std_formatter "@[with_oo:(x=%i; y=%i; y=%i)@]";;
with_oo:(x=- : int -> int -> int -> unit = <fun>


(*

# let t = new with_oo;;
val t : with_oo = <obj>
# t;;
- : with_oo = <obj>
# t#get_x;;
- : int = 0
# t#move 10;;
- : unit = ()
# t#get_x;;
- : int = 10
#

*)

*)

type nooo = {
  mutable x:int;
  mutable y:int;
  }

let nooo_init () =
  { x=0; y=0 }

let nooo_get_x this = this.x

let nooo_move this d =
  this.x <- this.x + d;
  this.y <- this.y + d

let test_nooo_speed () =
  for ii = 1 to 100000000 do
   let term = nooo_init () in
   nooo_move term ii
  done

let test_nooo_speed_2 () =
  let term = nooo_init () in
  for ii = 1 to 100000000 do
   nooo_move term ii
  done

let profile_function text f =
   let start_time = Unix.time () in
   begin
     f ();
     print_newline ();
     print_string text;
     print_string ": Run time = ";
     print_float ((Unix.time ()) -. start_time);
   end


let _ = profile_function "oo with create" test_oo_speed
let _ = profile_function "method call only" test_oo_speed_2

let _ = profile_function "create term and call function" test_nooo_speed
let _ = profile_function "call function" test_nooo_speed_2