From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1I3UvN-0004WB-MG for qemu-devel@nongnu.org; Wed, 27 Jun 2007 06:39:01 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1I3UvM-0004Vq-0D for qemu-devel@nongnu.org; Wed, 27 Jun 2007 06:39:01 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1I3UvL-0004Vn-U4 for qemu-devel@nongnu.org; Wed, 27 Jun 2007 06:38:59 -0400 Received: from server2linux.rebelnetworks.com ([66.135.41.201]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1I3UvL-0001S7-Gn for qemu-devel@nongnu.org; Wed, 27 Jun 2007 06:38:59 -0400 Received: from [82.10.236.70] (helo=phoenix2.frop.org) by server2linux.rebelnetworks.com with esmtp (Exim 4.66) (envelope-from ) id 1I3UvI-0003Em-OQ for qemu-devel@nongnu.org; Wed, 27 Jun 2007 05:38:57 -0500 From: Julian Seward Subject: Re: [Qemu-devel] [PATCH, RFC] More than 2G of memory on 64-bit hosts Date: Wed, 27 Jun 2007 11:32:51 +0100 References: <200706261454.16852.paul@codesourcery.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200706271132.51360.jseward@acm.org> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org > > Unfortunately C99 relaxed this requirement, and allowed abominations like > > the win64 ABI. > > > > This means you have a choice: Write standard conforming code (long) that > > works on all known systems except win64, or use features that do't exist > > on many systems. IIRC C99 types like intptr_t are not supported on > > several fairly common unix systems. > > In that case I'll vote for unsigned long. I'd pass the issue to those > doing a win64 port, if ever that happens. In Valgrind-world we use an alternative approach, which is to typedef a set of new integral types and use those exclusively, and not use the native 'int', 'long' etc. The new types have a single fixed meaning regardless of the host or guest and it is up to the configure script to set up suitable typedefs. At startup Valgrind checks the size and signedness of these types is as expected, so any configuration errors are caught. This has proved very helpful in porting to a number of platforms. J