From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <fmonnier@linux-nantes.fr.eu.org>
X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr
X-Spam-Level: 
X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled 
	version=3.1.3
X-Original-To: caml-list@yquem.inria.fr
Delivered-To: caml-list@yquem.inria.fr
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 6FE2CBC6C
	for <caml-list@yquem.inria.fr>; Wed,  6 Feb 2008 00:09:23 +0100 (CET)
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AgAAAFt7qEfVJFBblmdsb2JhbACQLgEBAQEHBAYHChEHnTM
X-IronPort-AV: E=Sophos;i="4.25,309,1199660400"; 
   d="scan'208";a="22252384"
Received: from mx-out.libertysurf.net (HELO mail.libertysurf.net) ([213.36.80.91])
  by mail4-smtp-sop.national.inria.fr with ESMTP; 06 Feb 2008 00:09:23 +0100
Received: from [192.168.1.2] (91.168.191.133) by mail.libertysurf.net (7.3.118.8)
        id 479F73A8001FA04A; Wed, 6 Feb 2008 01:08:19 +0100
From: Florent Monnier <fmonnier@linux-nantes.fr.eu.org>
Organization: l'Association Linux-Nantes
To: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Using OCaml's run-time from LLVM-generated native code
Date: Wed, 6 Feb 2008 00:08:08 +0100
User-Agent: KMail/1.8.2
References: <200802012124.56835.jon@ffconsultancy.com> <47A6F2E5.2000604@frisch.fr> <200802041336.22550.jon@ffconsultancy.com>
In-Reply-To: <200802041336.22550.jon@ffconsultancy.com>
MIME-Version: 1.0
Content-Disposition: inline
Message-Id: <200802060008.08563.fmonnier@linux-nantes.fr.eu.org>
Cc: Jon Harrop <jon@ffconsultancy.com>
X-Face: -0"dKXwF0PiXr]fa$^)NJY7$;waqUckGcM7&q,VU?Xv\[=CiVM]g]pDs^xmfU9+Q=Z,OdfMHUR-7Ao%evJh.=a<Hal!+44Srfm>iq,#r0Ux0dm'!l|zeAXj||$>1_(L<B!CC@-^"bubMeM8TP@O/yW28<0VyR$k&k=QRau!ArSqYPuI/?_cuj"h5G&-w"DRb|{>v4Hc",&F}sbHeK0`SBA$_|XP
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Spam: no; 0.00; ocaml's:01 run-time:01 camlparam:01 camlreturn:01 val:01 computed:01 wrote:01 caml-list:01 int:01 int:01 fib:01 fib:01 caml:02 slower:02 native:03 

Hi,

Jon Harrop wrote:
> int apply(int n) {
>   CAMLparam0();
>   CAMLlocal2(nv, fibn);
>   nv = copy_int64(n);
>   fibn = fib(nv);
>   caml_gc_full_major(0);
>   CAMLreturn(Int64_val(fib(nv)));
> }
>
> Is that correct?
>
> Next, this C code is 4x slower than the ocamlopt-generated equivalent. What 
> can be done to improve its performance without leaving C?

I don't know if it is a typo from you, or if it is me that don't understand 
the code, but it seems that fib(nv) is computed twice.
Shouldn't the second one be replaced by fibn, the result of the first one?