From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 62044 invoked by alias); 2 Feb 2016 12:29:29 -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 62028 invoked by uid 89); 2 Feb 2016 12:29:29 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:1643 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Tue, 02 Feb 2016 12:29:28 +0000 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 065788050A; Tue, 2 Feb 2016 12:29:27 +0000 (UTC) Received: from tucnak.zalov.cz ([10.3.113.11]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u12CTPdZ020997 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 2 Feb 2016 07:29:26 -0500 Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.15.2/8.15.2) with ESMTP id u12CTNMA007963; Tue, 2 Feb 2016 13:29:24 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.15.2/8.15.2/Submit) id u12CTMFf007962; Tue, 2 Feb 2016 13:29:22 +0100 Date: Tue, 02 Feb 2016 12:29:00 -0000 From: Jakub Jelinek To: Uros Bizjak Cc: "H.J. Lu" , Ilya Enkovich , GCC Patches Subject: Re: [PATCH, PR target/69454] Disable TARGET_STV when stack is not properly aligned Message-ID: <20160202122922.GQ3017@tucnak.redhat.com> Reply-To: Jakub Jelinek References: <20160127154448.GQ3017@tucnak.redhat.com> <20160127161137.GB16081@msticlxl57.ims.intel.com> <20160202115338.GP3017@tucnak.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-IsSubscribed: yes X-SW-Source: 2016-02/txt/msg00106.txt.bz2 On Tue, Feb 02, 2016 at 01:24:26PM +0100, Uros Bizjak wrote: > On Tue, Feb 2, 2016 at 12:53 PM, Jakub Jelinek wrote: > > >> The bottom line is ix86_minimum_alignment must return the correct > >> number for DImode or you can just turn off STV. My suggestion is > >> to use my patch. > > > > Uros, any preferences here? I mean, it is possible to use > > e.g. the ix86_option_override_internal and have H.J's ix86_minimum_alignment > > change as a safety net, in the usual case for -mpreferred-stack-boundary=2 > > we'll just disable TARGET_STV and ix86_minimum_alignment change won't do > > anything, as TARGET_STV will be false, and if for whatever case it gets > > through (target attribute, -mincoming-stack-boundary=, ...) > > ix86_minimum_alignment will be there to ensure enough stack alignment. > > Most of the smaller -mpreferred-stack-boundary= uses are -mno-sse anyway, > > and that is something we don't want to affect. > > IMO, we should disable STV when -mpreferred-stack-boundary < 3, as STV > is only an optimization. Perhaps we can also emit a "sorry" for > explicit -mstv in case stack boundary requirement is not satisfied. > *If* there is a need for -mstv with smaller stack boundary, we can > revisit this decision for later gcc versions. > > I think disabling STV is less surprising option than increasing stack > boundary behind the user's back. So, is http://gcc.gnu.org/ml/gcc-patches/2016-01/msg02129.html ok for trunk then (alone or with additional sorry, incremental or not?)? I believe it does just that. Jakub