From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: xen build error on gcc v4.5.0 Date: Wed, 18 Aug 2010 16:07:30 -0700 Message-ID: <4C6C67B2.60508@goop.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: "xen-devel@lists.xensource.com" , Masroor Vettuparambil , M A Young List-Id: xen-devel@lists.xenproject.org On 08/18/2010 12:55 PM, Keir Fraser wrote: > On 18/08/2010 20:44, "M A Young" wrote: > >> On Wed, 18 Aug 2010, Jeremy Fitzhardinge wrote: >>> Looks like a gcc bug. Older gccs can compute __RING_SIZE() as a >>> compile-time constant, but gcc 4.5.0 apparently isn't doing that. It >>> is, admittedly, a very complex expression, but gcc shouldn't regress >>> like this. I'm not sure how to work around it. >> One option is to use __CONST_RING_SIZE instead of __RING_SIZE if that is >> available. I had a similar problem compiling xen with gcc 4.5 where this >> worked. > Yes that is exactly why Jan Beulich introduced __CONST_RING_SIZE, in > xen-unstable:20975. Should be a simple patch to pv_ops netfront/back drivers > to make use of it. Ah, OK. I'll bring it across and sprinkle it around. J