From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17986 invoked by alias); 15 Nov 2012 17:47:34 -0000 Received: (qmail 17977 invoked by uid 22791); 15 Nov 2012 17:47:33 -0000 X-SWARE-Spam-Status: No, hits=-3.8 required=5.0 tests=AWL,BAYES_00,DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,FREEMAIL_FROM,KHOP_RCVD_TRUST,NML_ADSP_CUSTOM_MED,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE X-Spam-Check-By: sourceware.org Received: from mail-bk0-f47.google.com (HELO mail-bk0-f47.google.com) (209.85.214.47) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 15 Nov 2012 17:47:24 +0000 Received: by mail-bk0-f47.google.com with SMTP id jk7so849959bkc.20 for ; Thu, 15 Nov 2012 09:47:23 -0800 (PST) Received: by 10.204.5.205 with SMTP id 13mr792055bkw.111.1353001643334; Thu, 15 Nov 2012 09:47:23 -0800 (PST) Received: from sandifor-thinkpad.stglab.manchester.uk.ibm.com (gbibp9ph1--blueice1n1.emea.ibm.com. [195.212.29.67]) by mx.google.com with ESMTPS id ht18sm11089746bkc.14.2012.11.15.09.47.21 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 15 Nov 2012 09:47:22 -0800 (PST) From: Richard Sandiford To: Eric Botcazou Mail-Followup-To: Eric Botcazou ,gcc-patches@gcc.gnu.org, rdsandiford@googlemail.com Cc: gcc-patches@gcc.gnu.org Subject: Re: [6/8] Add strict volatile handling to bit_field_mode_iterator References: <87k3u3eybu.fsf@talisman.home> <1775073.QASfiHdzOH@polaris> <87fw4bvyrv.fsf@sandifor-thinkpad.stglab.manchester.uk.ibm.com> <2631532.Xhzk4x2KXd@polaris> Date: Thu, 15 Nov 2012 17:47:00 -0000 In-Reply-To: <2631532.Xhzk4x2KXd@polaris> (Eric Botcazou's message of "Thu, 15 Nov 2012 18:08:18 +0100") Message-ID: <87boeywyfw.fsf@sandifor-thinkpad.stglab.manchester.uk.ibm.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org X-SW-Source: 2012-11/txt/msg01286.txt.bz2 Eric Botcazou writes: >> The idea was to centralise the knowledge about what modes are valid >> rather than requiring every client to know the rules. From that point >> of view it seems inconsistent for the new interface to handle the >> bitregion_{start,end} restrictions (a correctness issue) but not the >> volatility restrictions (also a correctness issue). Especially when the >> interface already knows whether the field is volatile and already handles >> the choice between "narrow" and "wide" volatile bitfields. > > Richard B.'s idea is precisely to reimplement -fstrict-volatile bitfields on > top of bitregion_{start,end}, that's why I'm not sure we want to make it part > of the interface at all. OK. The current recursive force-mem-to-reg cases in store_bit_field_1 and extract_bit_field_1 don't handle -fstrict-volatile-bitfields at all, so this patch was trying to fix what seemed like an oversight. Is it OK to leave the code as-is (not handling -fstrict-volatile-bitfields), or do I need to add new code to the expmed.c routines? Richard