From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20163 invoked by alias); 18 Dec 2007 20:15:41 -0000 Received: (qmail 20147 invoked by uid 22791); 18 Dec 2007 20:15:40 -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; Tue, 18 Dec 2007 20:15:31 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.1) with ESMTP id lBIKDHAi026540; Tue, 18 Dec 2007 15:13:17 -0500 Received: from pobox.corp.redhat.com (pobox.corp.redhat.com [10.11.255.20]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id lBIKDEx8003013; Tue, 18 Dec 2007 15:13:16 -0500 Received: from livre.oliva.athome.lsd.ic.unicamp.br (vpn-14-104.rdu.redhat.com [10.11.14.104]) by pobox.corp.redhat.com (8.13.1/8.13.1) with ESMTP id lBIKDCJe016716; Tue, 18 Dec 2007 15:13:13 -0500 Received: from livre.oliva.athome.lsd.ic.unicamp.br (localhost.localdomain [127.0.0.1]) by livre.oliva.athome.lsd.ic.unicamp.br (8.14.2/8.14.1) with ESMTP id lBIKDBIL008820; Tue, 18 Dec 2007 18:13:11 -0200 Received: (from aoliva@localhost) by livre.oliva.athome.lsd.ic.unicamp.br (8.14.2/8.14.1/Submit) id lBIKD7hC008819; Tue, 18 Dec 2007 18:13:07 -0200 To: Robert Dewar Cc: Joe Buck , Geert Bosch , Daniel Berlin , Diego Novillo , Mark Mitchell , Ian Lance Taylor , Richard Guenther , gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org Subject: Re: Designs for better debug info in GCC References: <4749DE66.1090602@codesourcery.com> <4756B02D.9010302@google.com> <4aca3dc20712151903r46c9eceane35edb92d08240ac@mail.gmail.com> <4aca3dc20712161712w1133fb96qd66be0e9a0bb1716@mail.gmail.com> <20071217012735.GA9275@synopsys.com> <8DF14649-456C-40D6-94C5-DC3285EFD7C2@adacore.com> <20071218012438.GD2908@synopsys.com> <476765C7.5050106@adacore.com> <4767C7E1.8030707@adacore.com> From: Alexandre Oliva Errors-To: aoliva@oliva.athome.lsd.ic.unicamp.br In-Reply-To: <4767C7E1.8030707@adacore.com> (Robert Dewar's message of "Tue\, 18 Dec 2007 08\:15\:13 -0500") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (gnu/linux) Date: Tue, 18 Dec 2007 22:15:00 -0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2007-12/txt/msg00537.txt.bz2 On Dec 18, 2007, Robert Dewar wrote: > Alexandre Oliva wrote: >> On Dec 18, 2007, Robert Dewar wrote: >>> OK, so you are agreeing that good debuggability is impossible >>> with all the optimizations in place, so once again, let's have >>> an optimziation level that optimizes as far as possible without >>> harming debuggability. >> It's just that changing optimizations is precisely *against* the goals >> of my current project. So, don't expect significant efforts to this >> end from me at this time. > But you can't achieve the above criterion with your approach. Actually, you can. My approach is about ensuring the mapping between the location of source and implementation variables is correct. This is orthogonal to how much optimization you make. If you optimize more, more values or locations may become unavailable, but this is not about correctness (what fraction of the annotations point at locations that hold the correct value), and it's not even about completeness (what fraction of the source variables are represented at all locations they are available), it's just about theoretical completeness (what fraction of the source variables are represented at all locations they would be available without optimization). -- Alexandre Oliva http://www.lsd.ic.unicamp.br/~oliva/ FSF Latin America Board Member http://www.fsfla.org/ Red Hat Compiler Engineer aoliva@{redhat.com, gcc.gnu.org} Free Software Evangelist oliva@{lsd.ic.unicamp.br, gnu.org}