From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23497 invoked by alias); 4 Oct 2006 19:11:04 -0000 Received: (qmail 23485 invoked by uid 22791); 4 Oct 2006 19:11:03 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Wed, 04 Oct 2006 19:11:01 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1GVC8u-00013u-ID; Wed, 04 Oct 2006 15:10:56 -0400 Date: Wed, 04 Oct 2006 19:11:00 -0000 From: Daniel Jacobowitz To: janani@linux.ibm.com Cc: gdb-patches@sourceware.org, pgilliam@us.ibm.com, janani@us.ibm.com Subject: Re: [patch] Pushing Inferior Function Arguments onto Stack on PowerPC64 machines Message-ID: <20061004191056.GA4000@nevyn.them.org> Mail-Followup-To: janani@linux.ibm.com, gdb-patches@sourceware.org, pgilliam@us.ibm.com, janani@us.ibm.com References: <20061004150034.1xgq6l4picg0wgk4@imap.linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061004150034.1xgq6l4picg0wgk4@imap.linux.ibm.com> User-Agent: Mutt/1.5.13 (2006-08-11) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-10/txt/msg00014.txt.bz2 On Wed, Oct 04, 2006 at 03:00:34PM -0400, janani@linux.ibm.com wrote: > I am new to this, so my interpretation might not be completely > accurate, but the way I read the note below ( a snippet from the GNU > GCC Manual about passing function arguments in registers) is that > since PPC64 is big endian, even though the default is to pad downward > (i.e. right align), if the size if greater than the size of an int, > you need to pad upward (left align). You're trying to answer the wrong question :-) It's not "what does GCC do", but "what does the platform ABI say we should do". Is GCC conforming to the ABI? Is the ABI wrong, or out of date, or was Andrew's reading of it wrong, or... There could be a real problem here, so it's important that we understand what is _supposed_ to happen before we make a change. If GCC is violating the ABI, then either GCC or the ABI may need to be updated. If GDB is misinterpreting the ABI, then just GDB needs to be changed. -- Daniel Jacobowitz CodeSourcery