From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 129436 invoked by alias); 14 Nov 2018 12:14:43 -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 129417 invoked by uid 89); 14 Nov 2018 12:14:42 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-0.9 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_PASS autolearn=no version=3.3.2 spammy=Hx-languages-length:580 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 ESMTP; Wed, 14 Nov 2018 12:14:41 +0000 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 42B4C3138B9D; Wed, 14 Nov 2018 12:14:40 +0000 (UTC) Received: from tucnak.zalov.cz (ovpn-116-75.ams2.redhat.com [10.36.116.75]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DC2DD608F0; Wed, 14 Nov 2018 12:14:39 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.15.2/8.15.2) with ESMTP id wAECEbRe024778; Wed, 14 Nov 2018 13:14:38 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.15.2/8.15.2/Submit) id wAECEbIp024777; Wed, 14 Nov 2018 13:14:37 +0100 Date: Wed, 14 Nov 2018 12:14:00 -0000 From: Jakub Jelinek To: Segher Boessenkool Cc: Martin Sebor , Gcc Patch List Subject: Re: [PATCH] diagnose unsupported uses of hardware register variables (PR 88000) Message-ID: <20181114121437.GT11625@tucnak> Reply-To: Jakub Jelinek References: <20181114094757.GO11625@tucnak> <20181114113505.GW23873@gate.crashing.org> <20181114114001.GQ11625@tucnak> <20181114115038.GX23873@gate.crashing.org> <20181114120043.GR11625@tucnak> <20181114121136.GY23873@gate.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181114121136.GY23873@gate.crashing.org> User-Agent: Mutt/1.9.2 (2017-12-15) X-IsSubscribed: yes X-SW-Source: 2018-11/txt/msg01229.txt.bz2 On Wed, Nov 14, 2018 at 06:11:37AM -0600, Segher Boessenkool wrote: > It doesn't "break" anything because it currently isn't guaranteed to work > either. There is __builtin_frame_address(0) for this of course (well, > almost the same semantics, and it is actually well-defined and actually > works). Is there user code that tries to do this with a register var? I've seen such code many times over the years, don't have time to perform code searches for such kind of constructs now though. Jakub