From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id NAA20119; Fri, 16 Aug 2002 13:04:50 +0200 (MET DST) Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id NAA20134 for ; Fri, 16 Aug 2002 13:04:50 +0200 (MET DST) Received: from praseodumium.btinternet.com (praseodumium.btinternet.com [194.73.73.82]) by nez-perce.inria.fr (8.11.1/8.11.1) with ESMTP id g7GB4nj19433 for ; Fri, 16 Aug 2002 13:04:49 +0200 (MET DST) Received: from host217-41-51-249.in-addr.btopenworld.com ([217.41.51.249] helo=beertje.william.bogus) by praseodumium.btinternet.com with esmtp (Exim 3.22 #8) id 17feuM-00065c-00; Fri, 16 Aug 2002 12:04:46 +0100 Received: (from williamc@localhost) by beertje.william.bogus (8.11.6/8.11.6/SuSE Linux 0.5) id g7GB81401843; Fri, 16 Aug 2002 12:08:01 +0100 X-Authentication-Warning: beertje.william.bogus: williamc set sender to williamc@paneris.org using -f From: William Chesters MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15708.56593.451087.185083@beertje.william.bogus> Date: Fri, 16 Aug 2002 12:08:01 +0100 To: caml-list@inria.fr Subject: float array alignment; was Re: [Caml-list] Bigarray access speed In-Reply-To: References: <20020815225004.GA5959@gromit.it.su.se> X-Mailer: VM 6.95 under 21.4 (patch 4) "Artificial Intelligence" XEmacs Lucid Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk malc writes: > To get maximal speed of the inner loops data needs to be naturally > aligned. OCaml does nothing to enforce it for non-big arrays. Bigarrays on > the other hand are mmaped(4k on IA32) and you get perfectly aligned data > for free. I was thinking that maybe Array can be extended with > make[create]_aligned, for speed/space tradeoff. I did this once to be able to interface with Fortran libs on Sparc32, and I still have a patch (against ocaml-2.01) lying around. It was actually quite thoroughly tested, but it's probably not very tidy. The main gotcha iirc was getting output_value/input_value to preserve alignment :). ------------------- 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