From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 115155 invoked by alias); 21 Aug 2015 16:03:30 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 115146 invoked by uid 89); 21 Aug 2015 16:03:29 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=no version=3.3.2 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; Fri, 21 Aug 2015 16:03:29 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 04CAF8E3C0; Fri, 21 Aug 2015 16:03:28 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t7LG3QLF007686; Fri, 21 Aug 2015 12:03:27 -0400 Message-ID: <55D74BCE.5020206@redhat.com> Date: Fri, 21 Aug 2015 16:03:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Luis Machado , gdb-patches@sourceware.org Subject: Re: [PATCH] Prevent GCC from folding inline test functions References: <1440162341-26343-1-git-send-email-lgustavo@codesourcery.com> In-Reply-To: <1440162341-26343-1-git-send-email-lgustavo@codesourcery.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-08/txt/msg00578.txt.bz2 On 08/21/2015 02:05 PM, Luis Machado wrote: > The attached patch implements this by adding the new global variable z, set > to 0, that gets added in different ways to marker and inlined_fn. Since it > is 0, it doesn't affect any possible value checks that we may wish to do > in the future (we currently only check for values changed by bar). > > Ok? > OK, though you should probably make z volatile as well. Otherwise, soon enough, gcc with LTO sees that z is always 0: > +int z = 0; and then these compile down to the same again, and get folded: > + x += y - z; > + x += y + z; Thanks, Pedro Alves