From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24161 invoked by alias); 24 Jul 2002 02:07:19 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 24154 invoked from network); 24 Jul 2002 02:07:18 -0000 Received: from unknown (HELO localhost.localdomain) (66.60.148.227) by sources.redhat.com with SMTP; 24 Jul 2002 02:07:18 -0000 Received: from warlock.codesourcery.com (localhost.localdomain [127.0.0.1]) by localhost.localdomain (8.11.6/8.11.6) with ESMTP id g6O25aP01453; Tue, 23 Jul 2002 19:05:36 -0700 Date: Wed, 24 Jul 2002 03:22:00 -0000 From: Mark Mitchell To: Michael Matz , Gabriel Dos Reis cc: "gcc@gcc.gnu.org" Subject: Re: [tree-ssa] Simplifying TARGET_EXPR Message-ID: <22170000.1027476335@warlock.codesourcery.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-SW-Source: 2002-07/txt/msg01136.txt.bz2 > But e.g. strict aliasing makes such debugging also harder in a similar > way, because valid, but possibly surprising, transformations are made. We > do them anyway, so that also can't be the reason to not elide copy ctors > by default. I agree with the antecedent, but not the conclusion. :-) These are definitly analgous situations, but to me it is a matter of degree. In other words, the same considerations apply, but in different proportions, and therefore I reach a different conclusion. Inserting and removing function calls is -- in my opinion -- a more significant change in program semantics. I dn't feel too strongly about this. Maybe I am scarred by having worked on too many compilers that did this transformation strictly in the front end. -- Mark Mitchell mark@codesourcery.com CodeSourcery, LLC http://www.codesourcery.com