From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54515) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TLIYA-0002P7-FG for qemu-devel@nongnu.org; Mon, 08 Oct 2012 14:59:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TLIY8-0003Eg-F8 for qemu-devel@nongnu.org; Mon, 08 Oct 2012 14:59:34 -0400 Date: Mon, 8 Oct 2012 22:01:20 +0200 From: "Michael S. Tsirkin" Message-ID: <20121008200120.GB17303@redhat.com> References: <1349298662-16666-1-git-send-email-sw@weilnetz.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1349298662-16666-1-git-send-email-sw@weilnetz.de> Subject: Re: [Qemu-devel] [PATCH] qemu-barrier: Fix compiler version check for future gcc versions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Weil Cc: qemu-trivial@nongnu.org, qemu-devel@nongnu.org, qemu-stable@nongnu.org On Wed, Oct 03, 2012 at 11:11:02PM +0200, Stefan Weil wrote: > The current check will give a wrong result for gcc-5.x with x < 4. > Using QEMU_GNUC_PREREQ is simpler and fixes that issue. > > Signed-off-by: Stefan Weil > --- > > With current gcc versions (gcc-4.x) there is no problem. > Nevertheless, I suggest to fix this in stable versions, too. > > Regards > > Stefan Weil ACK for stable tree. > qemu-barrier.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/qemu-barrier.h b/qemu-barrier.h > index 7e11197..16f0942 100644 > --- a/qemu-barrier.h > +++ b/qemu-barrier.h > @@ -19,7 +19,7 @@ > * mfence on 32 bit as well, e.g. if built with -march=pentium-m. > * However, on i386, there seem to be known bugs as recently as 4.3. > * */ > -#if defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 4 > +#if QEMU_GNUC_PREREQ(4, 4) > #define smp_mb() __sync_synchronize() > #else > #define smp_mb() asm volatile("lock; addl $0,0(%%esp) " ::: "memory") > -- > 1.7.10