From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <benjamin.canou@gmail.com>
X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr
X-Spam-Level: *
X-Spam-Status: No, score=1.0 required=5.0 tests=AWL,SPF_NEUTRAL 
	autolearn=disabled version=3.1.3
Received: from mail4-relais-sop.national.inria.fr (mail4-relais-sop.national.inria.fr [192.134.164.105])
	by yquem.inria.fr (Postfix) with ESMTP id 2AD5EBC6C
	for <caml-list@yquem.inria.fr>; Fri, 18 Jan 2008 02:32:01 +0100 (CET)
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AgAAACOQj0dIDtyckmdsb2JhbACQFwEBAQEHAgYJChaVFYgA
X-IronPort-AV: E=Sophos;i="4.25,213,1199660400"; 
   d="scan'208";a="21452716"
Received: from fg-out-1718.google.com ([72.14.220.156])
  by mail4-smtp-sop.national.inria.fr with ESMTP; 18 Jan 2008 02:32:00 +0100
Received: by fg-out-1718.google.com with SMTP id l27so1150205fgb.43
        for <caml-list@yquem.inria.fr>; Thu, 17 Jan 2008 17:32:00 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=gamma;
        h=domainkey-signature:received:received:subject:from:to:content-type:date:message-id:mime-version:x-mailer:content-transfer-encoding;
        bh=VvmwIsZhKBXqEIqzXkpAs/4NKZ36rcuWF0VQyt7DOEg=;
        b=HMmCMh1S8S+QVjdK3NB/wBmsB1ElteUxBmUVk8YmtYlRuumpVO+dGw3wF0MI2FY6JpKNy8M/e6GdUJPpuomMWcaXTmQJ5dvqeuc6OkJE9a2f/qJhHQdRwc9WnSz+G8WkUlOu4Hgy9nCEUW9aRxOGKsBV+5nU2nTlWodNaNxFnv8=
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=subject:from:to:content-type:date:message-id:mime-version:x-mailer:content-transfer-encoding;
        b=sYfNodt5xrlZIy+e5Xxn6zFnFTxAYDzBPxIoAA8rk3tTaJ+xXdV17yxwB+QXswTeWJQmH1y7pfJj9flFf+NB8wZ1LGY4enHNkThWlJS01fGFiEJhCg/1sI+4c8RItnryEpifJHNFJKtQxXY1RLQBubBYlWgh6iye4Si/aUcQ4ls=
Received: by 10.86.50.8 with SMTP id x8mr2523250fgx.25.1200619920649;
        Thu, 17 Jan 2008 17:32:00 -0800 (PST)
Received: from ?192.168.0.10? ( [82.237.227.151])
        by mx.google.com with ESMTPS id l12sm3373707fgb.8.2008.01.17.17.31.58
        (version=SSLv3 cipher=RC4-MD5);
        Thu, 17 Jan 2008 17:31:59 -0800 (PST)
Subject: Strange performances
From: Benjamin Canou <benjamin.canou@gmail.com>
To: OCaml <caml-list@yquem.inria.fr>
Content-Type: text/plain
Date: Fri, 18 Jan 2008 02:32:13 +0100
Message-Id: <1200619933.6383.47.camel@benjamin-laptop>
Mime-Version: 1.0
X-Mailer: Evolution 2.12.1 
Content-Transfer-Encoding: 7bit
X-Spam: no; 0.00; bytecode:01 bug:01 failwith:01 endline:01 pred:01 ocamlopt:01 ocamlc:01 ocaml:01 -version:01 toplevel:01 123.:98 123.:98 rec:01 rec:01 benjamin:01 

  Hi,

The code following my message is way faster in bytecode than in native
code. Is there a good reason for that or is it a bug ?
Note : It is a (way too, I know) naive implementation of the well known
string suite 1, 11, 21, 1211, 111221, ...

  Benjamin Canou.

=== code ===

let list_of_string s =
  let rec list_of_string s i =
    try s.[i] :: list_of_string s (succ i)
    with _ -> []
  in list_of_string s 0

let rec trans = function
  | '1' :: '1' :: '1' :: tl -> "31" ^ trans tl
  | '1' :: '1' :: tl -> "21" ^ trans tl
  | '1' :: tl -> "11" ^ trans tl
  | '2' :: '2' :: '2' :: tl -> "32" ^ trans tl
  | '2' :: '2' :: tl -> "22" ^ trans tl
  | '2' :: tl -> "12" ^ trans tl
  | '3' :: '3' :: '3' :: tl -> "33" ^ trans tl
  | '3' :: '3' :: tl -> "23" ^ trans tl
  | '3' :: tl -> "13" ^ trans tl
  | [] -> ""
  | _ -> failwith "bad input"

let rec print n s =
  print_endline s ;
  if n > 0 then print (pred n) (trans (list_of_string s))
    
let _ = print 30 "1"

=== perfs ===

benjamin@benjamin-laptop:~/Work/Stuff$ ocamlopt 123.ml -o 123
benjamin@benjamin-laptop:~/Work/Stuff$ time ./123
[...]
real    0m5.245s
user    0m4.944s
sys     0m0.016s
benjamin@benjamin-laptop:~/Work/Stuff$ ocamlc 123.ml -o 123
benjamin@benjamin-laptop:~/Work/Stuff$ time ./123
[...]
real    0m1.097s
user    0m0.840s
sys     0m0.008s
benjamin@benjamin-laptop:~/Work/Stuff$ ocaml -version
The Objective Caml toplevel, version 3.09.2