From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Subject: Re: Making the NS83820 usable on IA64 Date: Tue, 16 Mar 2004 21:49:12 -0800 Sender: netdev-bounce@oss.sgi.com Message-ID: <20040316214912.32b4c530.davem@redhat.com> References: <16471.52400.222262.824746@wombat.disy.cse.unsw.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-ia64@vger.kernel.org, linux-net@vger.kernel.org, netdev@oss.sgi.com Return-path: To: Peter Chubb In-Reply-To: <16471.52400.222262.824746@wombat.disy.cse.unsw.edu.au> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Wed, 17 Mar 2004 14:57:36 +1100 Peter Chubb wrote: > The idea is to tell gcc that the IP header is 2-byte aligned, > so it can generate the right code to access it. Otherwise, it tries > to do a 4-byte load when trying to extract the header length bitfield, > which traps. As far as I read the C standard, gcc can do almost > whatever it wants as regarding the alignment and underlying storage > size of a bitfield, so it's free to assume 32-bit alignment if it > wants. This makes every piece of code only able to assume 2-byte alignment. I don't think this will get accepted :)