From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LBSV6-00084F-F5 for qemu-devel@nongnu.org; Sat, 13 Dec 2008 06:17:36 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LBSV5-00083i-LU for qemu-devel@nongnu.org; Sat, 13 Dec 2008 06:17:35 -0500 Received: from [199.232.76.173] (port=34790 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LBSV5-00083b-Gf for qemu-devel@nongnu.org; Sat, 13 Dec 2008 06:17:35 -0500 Received: from hall.aurel32.net ([88.191.82.174]:34353) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LBSV4-0002Oa-MY for qemu-devel@nongnu.org; Sat, 13 Dec 2008 06:17:35 -0500 Received: from volta.aurel32.net ([2002:52e8:2fb:1:21e:8cff:feb0:693b]) by hall.aurel32.net with esmtpsa (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from ) id 1LBSV3-00082G-EP for qemu-devel@nongnu.org; Sat, 13 Dec 2008 12:17:33 +0100 Received: from aurel32 by volta.aurel32.net with local (Exim 4.69) (envelope-from ) id 1LBSV2-0004DR-Rz for qemu-devel@nongnu.org; Sat, 13 Dec 2008 12:17:32 +0100 Date: Sat, 13 Dec 2008 12:17:32 +0100 From: Aurelien Jarno Subject: Re: [Qemu-devel] [5949] target-ppc: memory load/store rework Message-ID: <20081213111732.GE17729@volta.aurel32.net> References: <20081213011803.GC9457@miranda.arrow> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: 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 On Sat, Dec 13, 2008 at 09:25:54AM +0200, Blue Swirl wrote: > On 12/13/08, Stuart Brady wrote: > > On Mon, Dec 08, 2008 at 06:11:22PM +0000, Aurelien Jarno wrote: > > > - Don't swap values twice for bit-reverse load/store functions > > > in little endian mode. > > > > If I've read this correctly, it seems to me that we would still swap > > twice on little endian hosts when when emulating little endian mode or > > performing bit-reverse loads/stores. Bit-reverse loads/stores under > > little endian emulation on a little endian host would have actually > > resulted in *three* byteswaps! > > > > I'm not sure what the performance impact of this would be, but it's > > something that I've been wondering about while working on PA-RISC > > emulation, which will also need to provide a little endian mode. > > Jocelyn sent a patch to address this. There were some (small) problems > with it, so please read the full thread: > http://lists.gnu.org/archive/html/qemu-devel/2007-10/msg00289.html > That looks like a good start if someone wants to work again on that. The switch to TCG probably implies some more changes. -- .''`. Aurelien Jarno | GPG: 1024D/F1BCDB73 : :' : Debian developer | Electrical Engineer `. `' aurel32@debian.org | aurelien@aurel32.net `- people.debian.org/~aurel32 | www.aurel32.net