From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47856) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VumH9-0004N0-Bz for qemu-devel@nongnu.org; Sun, 22 Dec 2013 11:53:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VumH0-0006lv-Uj for qemu-devel@nongnu.org; Sun, 22 Dec 2013 11:53:11 -0500 Received: from mail-pb0-x22b.google.com ([2607:f8b0:400e:c01::22b]:57192) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VumH0-0006lg-My for qemu-devel@nongnu.org; Sun, 22 Dec 2013 11:53:02 -0500 Received: by mail-pb0-f43.google.com with SMTP id rq2so4472113pbb.30 for ; Sun, 22 Dec 2013 08:53:01 -0800 (PST) Sender: Richard Henderson Message-ID: <52B718EA.10500@twiddle.net> Date: Sun, 22 Dec 2013 08:52:58 -0800 From: Richard Henderson MIME-Version: 1.0 References: <1387644224-2404-1-git-send-email-aurelien@aurel32.net> <1387644224-2404-5-git-send-email-aurelien@aurel32.net> In-Reply-To: <1387644224-2404-5-git-send-email-aurelien@aurel32.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 4/5] tcg/i386: use movbe instruction in qemu_ldst routines List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Aurelien Jarno , qemu-devel@nongnu.org On 12/21/2013 08:43 AM, Aurelien Jarno wrote: > +/* If bit_MOVBE is defined in cpuid.h (added in GCC version 4.6), we are > + going to attempt to determine at runtime whether movbe is available. */ > +#if defined(CONFIG_CPUID_H) && defined(bit_MOVBE) > +static bool have_movbe; > +#else > +# define have_movbe 0 > +#endif > + Good point about checking bit_MOVBE, I missed that in my version. I do slightly prefer hoisting the mov opcode, as I do in my version. I think that tidies the 32 and 64-bit paths a bit. Nothing can really help adding extra conditionals to the 16-bit load paths though. r~