From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 58310 invoked by alias); 2 Nov 2015 21:48:30 -0000 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 Received: (qmail 58294 invoked by uid 89); 2 Nov 2015 21:48:28 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.5 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-qk0-f169.google.com Received: from mail-qk0-f169.google.com (HELO mail-qk0-f169.google.com) (209.85.220.169) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Mon, 02 Nov 2015 21:48:25 +0000 Received: by qkct129 with SMTP id t129so4390093qkc.2 for ; Mon, 02 Nov 2015 13:48:23 -0800 (PST) X-Received: by 10.55.21.65 with SMTP id f62mr32810475qkh.46.1446500903540; Mon, 02 Nov 2015 13:48:23 -0800 (PST) Received: from [192.168.0.26] (97-124-162-152.hlrn.qwest.net. [97.124.162.152]) by smtp.gmail.com with ESMTPSA id b137sm8569778qhc.37.2015.11.02.13.48.22 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 Nov 2015 13:48:22 -0800 (PST) Message-ID: <5637DA24.7090102@gmail.com> Date: Mon, 02 Nov 2015 21:48:00 -0000 From: Martin Sebor User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Gcc Patch List Subject: [PING] [PATCH] clarify documentation of -Q --help=optimizers References: <56299713.6040204@gmail.com> <562997A9.3090203@gmail.com> In-Reply-To: <562997A9.3090203@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2015-11/txt/msg00130.txt.bz2 Ping. Thanks in advance for a review. On 10/22/2015 08:12 PM, Martin Sebor wrote: > [Sending to the right list this time] > > The documentation of the -Q --help=optimizers options leads some > to expect that when options are reported as enabled imply the > corresponding optimization will take place. (See the following > question on gcc-help: > https://gcc.gnu.org/ml/gcc-help/2015-10/msg00133.html) > > The patch below tries to make it clear that that's not always > the case. > > Martin > > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index 4f89fa1..337639e 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -1506,6 +1506,16 @@ options, an indication is given as to whether the > option is enabled, > disabled or set to a specific value (assuming that the compiler > knows this at the point where the @option{--help=} option is used). > > +It's important to note that when a given optimization option is > +enabled, either explicitly on the command line or implicitly, whether > +or not the optimization it controls will be performed during an > +invocation of the compiler may depend on other options. This is > +so because many options control various finer aspects of other more > +general optimizations that must be enabled in order for the former > +option to have any effect. There is currently no command line > +interface to determine such dependencies between optimization > +options. > + > Here is a truncated example from the ARM port of @command{gcc}: > > @smallexample > >