From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17238 invoked by alias); 19 Jan 2007 15:30:20 -0000 Received: (qmail 17228 invoked by uid 22791); 19 Jan 2007 15:30:19 -0000 X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 19 Jan 2007 15:30:12 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id l0JFUAbX030441; Fri, 19 Jan 2007 10:30:10 -0500 Received: from potter.sfbay.redhat.com (potter.sfbay.redhat.com [172.16.27.15]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id l0JFU9ig001189; Fri, 19 Jan 2007 10:30:09 -0500 Received: from [10.14.51.32] (vpn-51-32.sfbay.redhat.com [10.14.51.32] (may be forged)) by potter.sfbay.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id l0JFU7oS009060; Fri, 19 Jan 2007 10:30:08 -0500 Message-ID: <45B0E3FA.2090801@redhat.com> Date: Fri, 19 Jan 2007 15:30:00 -0000 From: Dave Brolley User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206) MIME-Version: 1.0 To: Joern Rennecke CC: cgen@sources.redhat.com Subject: Re: subword semantics References: <20070119120733.GA2043@elsdt-razorfish.arc.com> In-Reply-To: <20070119120733.GA2043@elsdt-razorfish.arc.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact cgen-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cgen-owner@sourceware.org X-SW-Source: 2007-q1/txt/msg00012.txt.bz2 Joern Rennecke wrote: >What are the actual semantics of subword? >The documentation says that it is endian dependent, but the existing >bi-endian ports always use word 0 to refer to the most significant part. > > You are correct. The semantics are not endian dependent. Similar to the way shift operators are not endian dependent. The documentation also says that dependence on endianness was to be revisited. Perhaps that's what happend, or perhaps the intent was to recommend caution when using a (mem ...) expression as the operand of (subword ...) Dave