From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6844 invoked by alias); 13 Jun 2009 17:57:35 -0000 Received: (qmail 6836 invoked by uid 22791); 13 Jun 2009 17:57:34 -0000 X-SWARE-Spam-Status: No, hits=-2.4 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from mel.act-europe.fr (HELO mel.act-europe.fr) (212.99.106.210) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sat, 13 Jun 2009 17:57:28 +0000 Received: from localhost (localhost [127.0.0.1]) by filtered-smtp.eu.adacore.com (Postfix) with ESMTP id 5619C29001D; Sat, 13 Jun 2009 19:57:26 +0200 (CEST) Received: from mel.act-europe.fr ([127.0.0.1]) by localhost (smtp.eu.adacore.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mAfKb0cX7b0x; Sat, 13 Jun 2009 19:57:20 +0200 (CEST) Received: from [192.168.1.3] (88-122-76-122.rev.libertysurf.net [88.122.76.122]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mel.act-europe.fr (Postfix) with ESMTP id 013F8290006; Sat, 13 Jun 2009 19:57:20 +0200 (CEST) From: Eric Botcazou To: Richard Guenther Subject: Re: VTA guality assessment: better than -O0 ;-) Date: Sat, 13 Jun 2009 17:57:00 -0000 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: gcc@gcc.gnu.org, Alexandre Oliva References: <84fc9c000906130823yd6a6296x947a972c7d2535d5@mail.gmail.com> In-Reply-To: <84fc9c000906130823yd6a6296x947a972c7d2535d5@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200906132000.35949.ebotcazou@adacore.com> 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: 2009-06/txt/msg00291.txt.bz2 > Yes, I don't like -O0 producing worse debug info - what does > the -O0 -fvar-tracking-assignments results look like? I'd do the opposite: totally disable VTA at -O0 like we do for -fvar-tracking. We once tried to enable -fvar-tracking with -O0 at AdaCore and ended up with bloated and inferior debug info. I think we shouldn't need to do anything at -O0 apart from sufficiently curbing the code generator to get correct naive debug info; the sophisticated stuff should be reserved to -O and above. -- Eric Botcazou