From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 48598 invoked by alias); 24 Apr 2015 12:52:49 -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 48588 invoked by uid 89); 24 Apr 2015 12:52:48 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.2 X-HELO: eu-smtp-delivery-143.mimecast.com Received: from eu-smtp-delivery-143.mimecast.com (HELO eu-smtp-delivery-143.mimecast.com) (146.101.78.143) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 24 Apr 2015 12:52:47 +0000 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.140]) by uk-mta-11.uk.mimecast.lan; Fri, 24 Apr 2015 13:52:43 +0100 Received: from [10.2.207.6] ([10.1.2.79]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Fri, 24 Apr 2015 13:52:43 +0100 Message-ID: <553A3C9A.9080404@arm.com> Date: Fri, 24 Apr 2015 12:52:00 -0000 From: Alex Velenko User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Jeff Law , Steven Bosscher CC: GCC Patches , Marcus Shawcroft Subject: Re: [PATCH] [RTL] Relax CSE check to set REG_EQUAL notes. References: <1425467354-6018-1-git-send-email-alex.velenko@arm.com> <54FDDB1C.2000006@redhat.com> <55279458.6000601@arm.com> <55399987.9050207@redhat.com> In-Reply-To: <55399987.9050207@redhat.com> X-MC-Unique: 8YgBiJLQQkSytUgzAFJAAw-1 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes X-SW-Source: 2015-04/txt/msg01505.txt.bz2 On 24/04/15 02:16, Jeff Law wrote: > On 04/10/2015 03:14 AM, Alex Velenko wrote: >> On 09/03/15 17:40, Jeff Law wrote: >>> On 03/09/15 03:53, Steven Bosscher wrote: >>>> On Wed, Mar 4, 2015 at 12:09 PM, Alex Velenko wrote: >>>>> For example, in arm testcase pr43920-2.c, CSE previously decided not >>>>> to put >>>>> an "obvious" note on insn 9, as set value was the same as note value. >>>>> At the same time, other insns set up as -1 were set up through a >>>>> register >>>>> and did get a note: >>>> >>>> ...which is the point of the REG_EQUAL notes. In insn 8 there is a >>>> REG_EQUAL note to show that the value of r111 is known. In insn 9 the >>>> known value is, well, known from SET_SRC so there is no need for a >>>> REG_EQUAL note. Adding REG_EQUAL notes in such cases is just wasteful. >>> RIght. I'd rather look into why later passes aren't discovering >>> whatever equivalences are important rather than adding the redundant >>> notes. >>> >>> Regardless, I think this is a gcc-6 issue, so I'm not likely to look at >>> it in the immediate future. >>> >>> jeff >>> >>> >> Hi Jeff, >> I reworked the patch to satisfy your preference. >> >> This patch enables cfgcleanup.c to use const int rtx as REG_EQUAL notes. >> For example, this benefits Jump2 to find extra optimisation opportunitie= s. >> This patch fixes gcc.target/arm/pr43920-2.c for arm-none-eabi. >> >> Bootstraped on x86, run full regression run on arm-none-eabi and >> aarch64-none-elf. >> >> Is this patch ok? >> >> gcc/ >> >> 2015-03-17 Alex Velenko >> >> * cfgcleanup.c (can_replace_by): Use const int rtx of single set as >> REG_EQUAL note. > Now I finally see this in my queue. I recalled the discussion around > whether or not to add the redundant notes, but hadn't had a chance to > look at the updated patch. > > AFAICT, this is redundant with Shiva's patch, right? > > jeff > Hi Jeff, Yes, you are correct, this patch is now redundant. Kind regards, Alex