From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.33) id 1BsSrj-00054L-SD for qemu-devel@nongnu.org; Wed, 04 Aug 2004 17:00:03 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.33) id 1BsSri-00053v-83 for qemu-devel@nongnu.org; Wed, 04 Aug 2004 17:00:02 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1BsSrh-00053s-Q5 for qemu-devel@nongnu.org; Wed, 04 Aug 2004 17:00:02 -0400 Received: from [193.252.22.27] (helo=mwinf0408.wanadoo.fr) by monty-python.gnu.org with esmtp (Exim 4.34) id 1BsSo2-0004KA-RF for qemu-devel@nongnu.org; Wed, 04 Aug 2004 16:56:15 -0400 Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf0408.wanadoo.fr (SMTP Server) with SMTP id ECFA5180017D for ; Wed, 4 Aug 2004 22:56:13 +0200 (CEST) Received: from bellard.org (ATuileries-112-1-3-232.w81-48.abo.wanadoo.fr [81.48.134.232]) by mwinf0408.wanadoo.fr (SMTP Server) with ESMTP id 9247A18000D5 for ; Wed, 4 Aug 2004 22:56:13 +0200 (CEST) Message-ID: <41114D7E.7090201@bellard.org> Date: Wed, 04 Aug 2004 22:56:30 +0200 From: Fabrice Bellard MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: Performances on Mac OS X References: <000001c47a53$fc072f20$8cdb71d5@msgrus.se> In-Reply-To: <000001c47a53$fc072f20$8cdb71d5@msgrus.se> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Don't spend your time in using another compiler than gcc : most of the time is spent in the generated code, and the quality of this code relies on very small functions which are too simple for being optimized better. Fabrice. Roine Gustafsson wrote: > Joshua Root [z3022016@student.unsw.edu.au] wrote: > >>Laurent Amon wrote: >> >> >>>I was wondering whether the implementation of qemu is tied to gcc or >>>if it might >>>be interesting to try to compile using IBM's compiler, which is able >>>to generate >>>Altivec code... >> >>I have tried compiling qemu with xlc and it chokes on the asm. I >>believe that it uses a different syntax than gcc for this. I don't >>know what its syntax is, but if anybody does it shouldn't be too hard >>to make a patch which lets it compile. >> >>Using xlc does seem to give substantially better performance than >>gcc, and not just on floating point code. >> > > > xlc is picky with the source and takes FOREVER to compile with -O6. However, > xlc is object compatible with gcc, so usually you just use xlc on core stuff > that needs the speed, and gcc for everything else. > Compile everything with gcc, rm the object files you want to remake with xlc > (based on profiling), edit the makefiles to use xlc and make again. > > /Roine > > > > _______________________________________________ > Qemu-devel mailing list > Qemu-devel@nongnu.org > http://lists.nongnu.org/mailman/listinfo/qemu-devel >