From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10571 invoked by alias); 26 Nov 2012 14:47:55 -0000 Received: (qmail 10561 invoked by uid 22791); 26 Nov 2012 14:47:53 -0000 X-SWARE-Spam-Status: No, hits=-5.0 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,KHOP_RCVD_TRUST,KHOP_THREADED,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE,TW_TM X-Spam-Check-By: sourceware.org Received: from mail-oa0-f47.google.com (HELO mail-oa0-f47.google.com) (209.85.219.47) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 26 Nov 2012 14:47:49 +0000 Received: by mail-oa0-f47.google.com with SMTP id h1so11401797oag.20 for ; Mon, 26 Nov 2012 06:47:49 -0800 (PST) MIME-Version: 1.0 Received: by 10.60.3.8 with SMTP id 8mr9181725oey.101.1353941264127; Mon, 26 Nov 2012 06:47:44 -0800 (PST) Received: by 10.76.95.202 with HTTP; Mon, 26 Nov 2012 06:47:44 -0800 (PST) In-Reply-To: References: <1826073.rNRXULK6yo@polaris> <3309385.mAl1npuha0@polaris> Date: Mon, 26 Nov 2012 14:47:00 -0000 Message-ID: Subject: Re: [PATCH] Reset source location for instructions moved out of its original residing basic block From: Richard Biener To: Alexandre Oliva Cc: Dehao Chen , Eric Botcazou , GCC Patches , David Li Content-Type: text/plain; charset=ISO-8859-1 X-IsSubscribed: yes 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/msg02101.txt.bz2 On Sun, Nov 4, 2012 at 11:26 PM, Alexandre Oliva wrote: > On Nov 1, 2012, Dehao Chen wrote: > >> I see your point. How about we guard these changes with a flag, say >> -gless-jumpy > > The right (DWARF-expected) approach to avoid this sortof jumpiness is to > teach GCC to emit .locs with is_stmt=1, along the lines (and > limitations) described in my GCC Summit paper on stmt frontier notes, > that proposes further extensions to deal with the foreseen limitations. Right. gdb could also instead of show a single line (and that changing all the time) show all currently "active" lines (thus scan the current function for lines that appear and compute their "liveness"). A step would then jump to the next stmt that changes line liveness. Richard. > http://people.redhat.com/~aoliva/papers/sfn/gcc2010.pdf > > -- > Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/ > You must be the change you wish to see in the world. -- Gandhi > Be Free! -- http://FSFLA.org/ FSF Latin America board member > Free Software Evangelist Red Hat Brazil Compiler Engineer