From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10453 invoked by alias); 5 Dec 2001 18:42:36 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 10421 invoked from network); 5 Dec 2001 18:42:29 -0000 Received: from unknown (HELO localhost.cygnus.com) (216.138.202.10) by sources.redhat.com with SMTP; 5 Dec 2001 18:42:29 -0000 Received: from cygnus.com (localhost [127.0.0.1]) by localhost.cygnus.com (Postfix) with ESMTP id 14DC43D5E; Wed, 5 Dec 2001 13:42:21 -0500 (EST) Message-ID: <3C0E6A8C.9040306@cygnus.com> Date: Wed, 05 Dec 2001 10:42:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:0.9.3) Gecko/20011020 X-Accept-Language: en-us MIME-Version: 1.0 To: Richard.Earnshaw@arm.com Cc: twall@oculustech.com, gdb@sources.redhat.com Subject: Re: packing/unpacking 4-octet longs References: <200112051645.QAA06737@cam-mail2.cambridge.arm.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2001-12/txt/msg00041.txt.bz2 > I'm not aware of this affecting the ARM (except in that FPA format doubles > and long doubles always have the word with the exponent at the lowest > address, but there's nothing in the IEEE FP specs that says this is > invalid). In particular, storing a word, or multi-word, at an unaligned > address does not change the order of bytes in memory, so > memcpy(unaligned_address, aligned_address, sizeof(some_word)) > does not require diddling with the internal order (or have I misunderstood > the problem?) That was a useful manual :-) See 5-21 where it explains that a misaligned 32bit access gets rotated before it is stored :-/ enjoy, Andrew