From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23413 invoked by alias); 30 Apr 2004 18:29:25 -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 23405 invoked from network); 30 Apr 2004 18:29:22 -0000 Received: from unknown (HELO igw2.watson.ibm.com) (129.34.20.6) by sources.redhat.com with SMTP; 30 Apr 2004 18:29:22 -0000 Received: from sp1n293en1.watson.ibm.com (sp1n293en1.watson.ibm.com [129.34.20.41]) by igw2.watson.ibm.com (8.11.7-20030924/8.11.4) with ESMTP id i3UITLU112506; Fri, 30 Apr 2004 14:29:21 -0400 Received: from makai.watson.ibm.com (localhost [127.0.0.1]) by sp1n293en1.watson.ibm.com (8.11.7-20030924/8.11.7/8.11.7-01-14-2004) with ESMTP id i3UITLv52330; Fri, 30 Apr 2004 14:29:21 -0400 Received: from watson.ibm.com (localhost [127.0.0.1]) by makai.watson.ibm.com (AIX5.1/8.11.6p2/8.11.0/03-06-2002) with ESMTP id i3UITJT25920; Fri, 30 Apr 2004 14:29:19 -0400 Message-Id: <200404301829.i3UITJT25920@makai.watson.ibm.com> To: gcc@gcc.gnu.org, Dave Korn , Phil Edwards Subject: Re: optimization issue about -O2 and -Os In-Reply-To: Message from Phil Edwards of "Fri, 30 Apr 2004 14:15:16 EDT." <20040430181516.GB10422@disaster.jaj.com> References: <87y8odiepk.fsf@egil.codesourcery.com> <20040430181516.GB10422@disaster.jaj.com> Date: Fri, 30 Apr 2004 20:09:00 -0000 From: David Edelsohn X-SW-Source: 2004-04/txt/msg01466.txt.bz2 >>>>> Phil Edwards writes: Phil> On Fri, Apr 30, 2004 at 06:21:26PM +0100, Dave Korn wrote: >> Hmm, maybe it would be worthwhile to invent -f options for all these >> ad-hoc tests on the optimize variables, so that the -O options then *did* >> become shorthand for flag sets, and the suggestion I already made for >> localising the failure with a given -O setting would actually work? Phil> We need fewer -f options, really, not more of them. Phil> Or to put it another way: if an optimization pass is buggy, it doesn't Phil> deserve to have an -f option yet. I think this is confusing two different motivations and trying to create a single answer for both, which will not work. If one considers -f options as intended only for the general user, there probably are too many. However, if one is performing component/unit testing or debugging or performance tuning or providing consulting services, there are not enough options. Developers and advanced users should be able to enable and disable every optimization option at a fine granularity at compile time, not when building GCC. Labeling those as "-f" options and documenting them for the general user is a separate issue. David