From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1EaTpE-0000ge-3P for qemu-devel@nongnu.org; Fri, 11 Nov 2005 02:59:56 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1EaTpC-0000gA-4J for qemu-devel@nongnu.org; Fri, 11 Nov 2005 02:59:55 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1EaTpB-0000fd-8s for qemu-devel@nongnu.org; Fri, 11 Nov 2005 02:59:53 -0500 Received: from [69.17.117.27] (helo=mail25.sea5.speakeasy.net) by monty-python.gnu.org with esmtp (TLS-1.0:DHE_RSA_3DES_EDE_CBC_SHA:24) (Exim 4.34) id 1EaTpB-0005uD-C6 for qemu-devel@nongnu.org; Fri, 11 Nov 2005 02:59:53 -0500 Received: from dsl081-088-222.lax1.dsl.speakeasy.net (HELO [192.168.111.2]) (jhoger@[64.81.88.222]) (envelope-sender ) by mail25.sea5.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 11 Nov 2005 07:59:45 -0000 Subject: Re: [Qemu-devel] patch for qemu with newer gcc-3.4.x (support repz retq optimization for amd processors correctly) From: "John R. Hogerhuis" In-Reply-To: <20051110014404.GC2321@mail.shareable.org> References: <43724B52.3050101@mail.ru> <200511091945.26239.paul@codesourcery.com> <4372532E.4090104@mail.ru> <200511100133.55709.jseward@acm.org> <20051110014404.GC2321@mail.shareable.org> Content-Type: text/plain Date: Thu, 10 Nov 2005 23:59:43 -0800 Message-Id: <1131695984.6973.17.camel@aragorn> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Reply-To: jhoger@pobox.com, 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 On Thu, 2005-11-10 at 01:44 +0000, Jamie Lokier wrote: > > > > The use of gcc to generate the back end in QEMU's early days was a > > clever way to get the project up and running quickly. But surely > > now it would be better to transition to a handwritten backend, so > > It should be trivial to take the _currently_ generated GCC code for > all the architectures QEMU is commonly built on, and just distribute > that code with the QEMU source. > > Then it would be independent of future changes to GCC. > > I understand a handwritten backend is already being written. But > until a proper one is done, wouldn't that serve as a useful stopgap? > > -- Jamie > I you poke around in the archives, this idea was raised before (by me, maybe). I think it would work, but I didn't hear a lot of enthusiasm for it. I think it would also open the door for hand-tweaking critical areas for performance. Paul Brook has another take, and the benefit of his is you can look at real life code to see how it will work. -- John.