From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38968) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEObG-0000ks-J0 for qemu-devel@nongnu.org; Wed, 19 Sep 2012 14:02:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TEOb3-0001w1-1X for qemu-devel@nongnu.org; Wed, 19 Sep 2012 14:02:14 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:65430) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEOb2-0001vq-Ru for qemu-devel@nongnu.org; Wed, 19 Sep 2012 14:02:00 -0400 Received: by pbbrp12 with SMTP id rp12so3024526pbb.4 for ; Wed, 19 Sep 2012 11:02:00 -0700 (PDT) Sender: Richard Henderson Message-ID: <505A0895.8000008@twiddle.net> Date: Wed, 19 Sep 2012 11:01:57 -0700 From: Richard Henderson MIME-Version: 1.0 References: <5059FA36.1080301@twiddle.net> <505A011C.1020106@twiddle.net> <20120919175116.GC29951@hall.aurel32.net> In-Reply-To: <20120919175116.GC29951@hall.aurel32.net> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Shifts, ppc[64], xtensa List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Aurelien Jarno Cc: Peter Maydell , qemu-devel@nongnu.org, Max Filippov On 09/19/2012 10:51 AM, Aurelien Jarno wrote: > That said it is not a valid reason to not keep the value during > re-translation, as it means the TB will exit instead of linking to > the next one. The consequences are only the performance. We still have the problem of when is the goto_tb link initialized the *first* time? Where we expect the goto_tb to fall through to stuff+exit_tb? For i386 it's during translation, with no care for re-translation. For ARM? I can't see that it is. For PPC, malc has already verified that it *never* happens. If he puts "trap" insns there instead of "nop" insns, he'll see the trap. r~