From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail1-relais-roc.national.inria.fr (mail1-relais-roc.national.inria.fr [192.134.164.82]) by walapai.inria.fr (8.13.6/8.13.6) with ESMTP id p7PALHkm016174 for ; Thu, 25 Aug 2011 12:21:17 +0200 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AtYAAG0hVk7U4367kWdsb2JhbABCFoQ2ozUUAQEBAQkLCwcUAyKBQAEBAwEBI1YQCxgCAiYCAlcGEwmHaQICqXWRUoEshA+BEQSMA4wji3A X-IronPort-AV: E=Sophos;i="4.68,280,1312149600"; d="scan'208";a="117125383" Received: from moutng.kundenserver.de ([212.227.126.187]) by mail1-smtp-roc.national.inria.fr with ESMTP; 25 Aug 2011 12:21:12 +0200 Received: from office1.lan.sumadev.de (dslb-188-097-007-157.pools.arcor-ip.net [188.97.7.157]) by mrelayeu.kundenserver.de (node=mreu4) with ESMTP (Nemesis) id 0LpUgc-1RPpzf3pn4-00fPT3; Thu, 25 Aug 2011 12:21:10 +0200 Received: from [192.168.1.111] (546BF154.cm-12-4d.dynamic.ziggo.nl [84.107.241.84]) by office1.lan.sumadev.de (Postfix) with ESMTPSA id 8A67DC00C7; Thu, 25 Aug 2011 12:21:09 +0200 (CEST) From: Gerd Stolpmann To: Benedikt Meurer Cc: caml-list@inria.fr, Fischbach Marcell In-Reply-To: References: <93199F3B-E9CF-4D93-9B2B-BAAB03F4FC08@googlemail.com> <4EF51F29-D437-4F6F-9C91-DBEA3D4C3EB8@googlemail.com> <1314218451.3496.42.camel@thinkpad> <11577B43-4270-4BA4-AA77-7FDEFB4B563B@googlemail.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 25 Aug 2011 12:21:08 +0200 Message-ID: <1314267668.3496.62.camel@thinkpad> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit X-Provags-ID: V02:K0:UoxkeOUZtQw7PR3SS2DHaTpizLuTuk+ZiJOuPCYGe1k a/eGTwJE4v/eTfGPgdKq3S5xf+zDs40qDLoslBbeRPHscqOrIl L8Z7ROcE/5591lC+gUngFuCL1vbeUvAGqV47RmZZcRbRoyW0/k 2DBsnXpwhjcDgk+/MXgShHKbsTkwvcW+EVBKavRrmZybjshc1D H7ufzh9LYzsfqMjmhI6ig== Subject: Re: [Caml-list] Linear Scan Register Allocator for ocamlopt/ocamlnat Am Donnerstag, den 25.08.2011, 11:34 +0200 schrieb Benedikt Meurer: > On Aug 25, 2011, at 10:02 , Benedikt Meurer wrote: > > >>> - http://ps.informatik.uni-siegen.de/~meurer/tmp/compiletime_timings.pdf contains a comparison of the ocamlopt invocations. > >>> - http://ps.informatik.uni-siegen.de/~meurer/tmp/runtime_timings.pdf contains comparison of the generated code. > >>> > >>> As can be seen from the results, amd64 is more sensitive to register allocator changes than i386. > >> > >> Well, this particular i386 CPU model is a strange guy - Northwoods have > >> this extremely long pipeline, which is very sensitive to unforeseen > >> jumps. It would be more interesting to see this test on a modern CPU in > >> i386 mode. My guess is that it behaves then more like amd64. > > > > Modern CPUs most probably don't run ocaml in 32bit mode, but more likely in long mode. That's why we choose to run the i386 on "real 32bit hardware", where the ocaml i386 port is actually used. Right. However, if you look at new 32-bit-only CPUs like older Atoms these base on modern cores where only some of the circuits were omitted that are needed for 64-bit execution. > > > > I'll rerun the benchmark in 32bit mode on a modern cpu to see how things change. > > Reran the benchmark with 32bit ocaml on the MBP (Early 2011), results are available at: > > http://ps.informatik.uni-siegen.de/~meurer/tmp/linscan-i7-i386-timings.pdf Hard to interpret. I have the impression that the compile times for graph coloring on i386 are lower than on amd64 - has maybe to do with the number of registers - but those for linear scanning are about the same. (I'm comparing here with the amd64 numbers taken on the same machine.) The graphs for the runtimes are on a logarithmic scale. Do you also have raw numbers? Gerd > > Benedikt > > > -- ------------------------------------------------------------ Gerd Stolpmann, Darmstadt, Germany gerd@gerd-stolpmann.de Creator of GODI and camlcity.org. Contact details: http://www.camlcity.org/contact.html Company homepage: http://www.gerd-stolpmann.de *** Searching for new projects! Need consulting for system *** programming in Ocaml? Gerd Stolpmann can help you. ------------------------------------------------------------