From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Delivered-To: caml-list@yquem.inria.fr Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by yquem.inria.fr (Postfix) with ESMTP id 89052BC84 for ; Wed, 30 Mar 2005 14:52:55 +0200 (CEST) Received: from ptb-relay01.plus.net (ptb-relay01.plus.net [212.159.14.212]) by concorde.inria.fr (8.13.0/8.13.0) with ESMTP id j2UCqsiL011416 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 30 Mar 2005 14:52:54 +0200 Received: from [80.229.56.224] (helo=chetara) by ptb-relay01.plus.net with esmtp (Exim) id 1DGcgm-0005Ke-Li for caml-list@yquem.inria.fr; Wed, 30 Mar 2005 12:52:52 +0000 From: Jon Harrop Organization: Flying Frog Consultancy Ltd. To: caml-list@yquem.inria.fr Subject: Re: [Caml-list] 32- and 64-bit performance Date: Wed, 30 Mar 2005 13:53:35 +0100 User-Agent: KMail/1.7.1 References: <200503300340.15874.jon@ffconsultancy.com> <424A6632.1020902@barettadeit.com> <1112173304.27770.22.camel@dsws> In-Reply-To: <1112173304.27770.22.camel@dsws> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200503301353.35474.jon@ffconsultancy.com> X-Miltered: at concorde with ID 424AA126.003 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Spam: no; 0.00; caml-list:01 deallocation:01 pointer:01 ocaml:01 ocaml:01 run-time:01 arrays:01 constructors:01 ...:98 ...:98 frog:98 wrote:01 polymorphic:01 polymorphic:01 slower:01 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on yquem.inria.fr X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.0.2 X-Spam-Level: On Wednesday 30 March 2005 10:01, Ville-Pertti Keinonen wrote: > Back when I got my first amd64 machine... =:-p > Note that it isn't memory allocation and deallocation that is slower (on > amd64, memory allocation is probably faster, since the allocation > pointer is kept in a register), but programs that use fairly large > amounts of memory. 32-bit vs. 64-bit might be the difference between > everything fitting in L2 or not... Yes. I was thinking that the GC would be slower due to worse cache use in 64-bit. I used the phrase "de/allocation" as I was applying it to both C++ and OCaml. This raises the question of exactly which OCaml types incur 64-bit quantities in the run-time. My guess: int (d'oh) constant (polymorphic) variant constructor? non-constant (polymorphic) variant constructor records (except those with all-float fields) tuples arrays But isn't there quite a low limit on the number of constant variant type constructors allowed? So maybe they're squeezed into something a little smaller... -- Dr Jon D Harrop, Flying Frog Consultancy Ltd. Objective CAML for Scientists http://www.ffconsultancy.com/products/ocaml_for_scientists