From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 111950 invoked by alias); 2 Jul 2019 19:09:56 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 111937 invoked by uid 89); 2 Jul 2019 19:09:56 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=no version=3.3.1 spammy=Kindly, Due, guys, H*c:alternative X-HELO: mail-ot1-f42.google.com Received: from mail-ot1-f42.google.com (HELO mail-ot1-f42.google.com) (209.85.210.42) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 02 Jul 2019 19:09:54 +0000 Received: by mail-ot1-f42.google.com with SMTP id x21so18327178otq.12 for ; Tue, 02 Jul 2019 12:09:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=be5zHj28SLqTprVdYYYjPNE+oHFPy674ve7Tj+jksgQ=; b=u2SKiH0y9wWCmnxROscYo8kcowBcyCq75Edl/KsQ4NJqc77GY8l+VO4tKUYhBB1Thf T3gMGLWAuG1Ze75lnDXExn6vntfglLLMFEUdvrZqoLHpFWBgrGO/1/6BaF58BRRuEUGM DAsi21greV+wePs5oFjPWxa0X/mRrnhiHiZNc1GMAVpx4SGGVycMq0n6MzyiDRdHTqMB 0PIh+aKG8koHHh7jrRWgvE9WM1Qq085FbnYtsQvo249z+LOg88vtu5bqhExgCttRzH1l uU3VgK7wDQ5doqV8R46g+EKM17xClzqzJ2IZ0RQ0+Ebm2hoGjCVlDmGNvdafoBbNkkCB KbGg== MIME-Version: 1.0 References: <20190620140600.GA15142@linux.ibm.com> <20190702123809.GM26519@linux.ibm.com> <20190702150931.GR26519@linux.ibm.com> In-Reply-To: <20190702150931.GR26519@linux.ibm.com> From: Akshat Garg Date: Tue, 02 Jul 2019 19:09:00 -0000 Message-ID: Subject: Re: Doubts regarding the _Dependent_ptr keyword To: Paul McKenney Cc: Ramana Radhakrishnan , gcc mailing list Content-Type: text/plain; charset="UTF-8" X-SW-Source: 2019-07/txt/msg00029.txt.bz2 On Tue, Jul 2, 2019 at 8:40 PM Paul E. McKenney wrote: > On Tue, Jul 02, 2019 at 02:15:55PM +0100, Ramana Radhakrishnan wrote: > > On Tue, Jul 2, 2019 at 1:38 PM Paul E. McKenney > wrote: > > > > > > > > Once a user-created non-dependent pointer is assigned to, it is OK to > > > break the dependency. > > > > Ok, that's good. > > > > > > Or am I missing the point here? > > > > I was just trying to make sure we were on the same page. I wonder if > > marking this volatile would be sufficient for prototyping. I suspect > > we would need another flag somewhere which someone with gimple > > knowledge might be able to help us with. > > I expect that marking it as volatile would do the trick. ;-) > > Thanx, Paul > So, marking this pointer as volatile will not allow the compiler to modify/optimize the statements, the pointer is appearing in. And we don't need to push any other code inside any of the passes. Due to this, we want to automatically say those dependent pointers are volatile and introduce a new flag for this. Am I getting you guys correctly? Kindly, let me know? Akshat > > > regards > > Ramana > > > > > > > > Thanx, Paul > > > > > > > Ramana > > > > >> > > > > >> > > > > >> > Does this sounds like a workable plan for ? Let me know your > thoughts. If this sounds good then, we can do this for all the > optimizations that may kill the dependencies at somepoint. > > > > >> > > > > > >> > -Akshat > > > > > > > > > > >