From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 34243 invoked by alias); 30 May 2017 10:30:47 -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 34140 invoked by uid 89); 30 May 2017 10:30:36 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.suse.de Received: from mx2.suse.de (HELO mx1.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 30 May 2017 10:30:35 +0000 Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 533EFAAB9; Tue, 30 May 2017 10:30:37 +0000 (UTC) Subject: Re: [RFC] [PATCH] Introduce configure flag --with-stage1-cflags. To: Eric Botcazou , Richard Biener Cc: gcc-patches@gcc.gnu.org, Jakub Jelinek References: <41109217-1bf5-b112-e783-8040196fd410@suse.cz> <6237251.LWo8Wt74zX@polaris> <8222700.x4IQrGbyC3@polaris> From: =?UTF-8?Q?Martin_Li=c5=a1ka?= Message-ID: <501b870c-ab03-319b-e174-47f63813f1f9@suse.cz> Date: Tue, 30 May 2017 10:33:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <8222700.x4IQrGbyC3@polaris> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2017-05/txt/msg02247.txt.bz2 On 05/30/2017 11:43 AM, Eric Botcazou wrote: >> Are you sure? In my experience -O2 gets the most test coverage during >> lifetime of a particular release. > > Yes, some older GCC releases have aliasing issues that are exposed at -O2 only > because of -fstrict-aliasing and -fschedule-insns. > That's why we decided to enable -O2 just with GCC 4.8+. Martin