From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 697 invoked by alias); 10 Jun 2011 14:02:12 -0000 Received: (qmail 679 invoked by uid 22791); 10 Jun 2011 14:02:11 -0000 X-SWARE-Spam-Status: No, hits=-6.4 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 10 Jun 2011 14:01:58 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p5AE1vNV019629 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 10 Jun 2011 10:01:57 -0400 Received: from [127.0.0.1] ([10.3.113.14]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p5AE1urd002052; Fri, 10 Jun 2011 10:01:56 -0400 Message-ID: <4DF223D4.3080700@redhat.com> Date: Fri, 10 Jun 2011 14:03:00 -0000 From: Jason Merrill User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc14 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: Richard Guenther CC: Richard Guenther , gcc-patches List Subject: Re: RFA (fold): PATCH for c++/49290 (folding *(T*)(ar+10)) References: <4DEDB98F.6010508@redhat.com> <4DEE2DCF.7020905@redhat.com> <4DEE3484.8030101@redhat.com> <4DF11FBC.3010304@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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: 2011-06/txt/msg00841.txt.bz2 On 06/10/2011 04:35 AM, Richard Guenther wrote: > I'm out of good suggestions ;) You can do the same-qualifier matching > and simply have a mismatched array element vs. array-ref type. But I need to allow different qualifiers, too. > We could also argue that whoever calls fold_indirect_ref_1 with TYPE > that doesn't even have TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (op0 (!))) > == TYPE_MAIN_VARIANT (type) is broken. Right, I only want to fold if the main variants match. > Thus we could argue that > even ignoring qualifiers is ok - but I'd be worried about folding > *((volatile int *)&a[0] + 1) to a[1] with lost volatile qualification. Right. It would be correct to fold it to VIEW_CONVERT_EXPR but I'm not sure how well front ends would deal with that. Maybe I'll try it and see. Jason