From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail1-relais-roc.national.inria.fr (mail1-relais-roc.national.inria.fr [192.134.164.82]) by yquem.inria.fr (Postfix) with ESMTP id 9FBE0BC37 for ; Mon, 11 Jan 2010 01:47:38 +0100 (CET) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AtkCAKADSksjCUvsi2dsb2JhbACDXpgCAQEBCgsKGqwcgVsBMIN8hT8GgSuCLlY X-IronPort-AV: E=Sophos;i="4.49,252,1262559600"; d="scan'208";a="44579576" Received: from sys56.mail.msu.edu ([35.9.75.236]) by mail1-smtp-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-SHA; 11 Jan 2010 01:47:38 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=msu.edu; s=mail; h=Message-ID:Date:From:MIME-Version:To:CC:Subject: References:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=XxlHyclLqjtPTZeqkKWM8iKGS9YzKql9sryB/rtFGnw=; b=YcjuUhbwiHHJZ fCzqo5kC3+mb7aST3H433b1H5kcv/RNcV7EQvQHIlbenIgPZmWzbkoaRLgtxtLv/ PFEqUdS8cGTjMLqd4MCFxX3Funv+aMAKetj5C3LUdjiK+8LFyOc4H6zS+Sfl+UEL h4PCbB0Afhi+n65wn9lhp+MxHDtDQo= Received: from c-24-56-235-190.customer.broadstripe.net ([24.56.235.190] helo=[192.168.1.4]) by sys56.mail.msu.edu with esmtpsa (Exim 4.69 #1) (TLSv1:CAMELLIA256-SHA:256) id 1NU8RT-0004U4-LY; Sun, 10 Jan 2010 19:47:35 -0500 Message-ID: <4B4A751E.1050905@msu.edu> Date: Sun, 10 Jan 2010 19:47:26 -0500 From: Jeff Shaw User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.5) Gecko/20091204 Thunderbird/3.0 MIME-Version: 1.0 To: Jon Harrop Cc: caml-list@yquem.inria.fr Subject: Re: [Caml-list] Re: HLVM ray tracer performance References: <20100110132942.1995706rwh00q1zq@mail.msu.edu> <201001102014.29726.jon@ffconsultancy.com> In-Reply-To: <201001102014.29726.jon@ffconsultancy.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus: None found by Clam AV X-Spam: no; 0.00; compilation:01 compiler:01 ubuntu:98 ubuntu:98 12.:98 stack:01 stack:01 caml-list:01 ghc:01 ghc:01 sys:03 sys:03 seems:03 optimization:03 overflow:03 > Are you running x64 or on Intel hardware? What results do you get for 12, 13 > or 14 instead of 9? > > I am running an AMD Phenom 9950, but the Ubuntu I'm using is just 32-bit. I tried 5/ray.hs with level=12 instead of 9 but it ran into a stack overflow problem. When I increased the stack size it completed but it also took more time than 1/ray.hs, which required no stack size increase. I made sure that the other arguments I fed it were the same. I think there is some problem that needs to be worked out in the 5/ray.hs. Maybe the problem is in ghc, I'm not sure. Below, ./ray5 is 5/ray.hs, and ./ray is 1/ray.hs jeff@ubuntu:~/Desktop$ time ./ray 12 512 > /dev/null real 0m21.479s user 0m21.093s sys 0m0.180s jeff@ubuntu:~/Desktop$ time ./ray5 12 512 +RTS -K2000000000 > /dev/null real 0m28.366s user 0m25.674s sys 0m2.608s jeff@ubuntu:~/Desktop$ time ./ray 14 512 > /dev/null real 0m23.544s user 0m23.021s sys 0m0.500s I tried level=14 but I ran out of memory for 5/ray.ml and 5/ray.hs. I considered that maybe I had saved the files from your website wrong, or mixed them up during compilation. So I ran the timer again with level=9 and level=12 and got all the same results. That is, level=9 is faster on 5/ray.hs but level=12 is faster with 1/ray.hs. So I don't think I'm making a simple manual labor error. It seems that 5/ray.ml and 5/ray.hs aren't quite equivalent in some important way since 1/ray.ml is faster than 5/ray.ml for both level=9 and level=12. Whether it's a code problem or compiler problem, I cannot say. The stack size problem does not go away when I remove all the extra optimization arguments to ghc. --Jeff