From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 46547 invoked by alias); 1 May 2015 11:39:28 -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 46537 invoked by uid 89); 1 May 2015 11:39:27 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-wi0-f178.google.com Received: from mail-wi0-f178.google.com (HELO mail-wi0-f178.google.com) (209.85.212.178) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Fri, 01 May 2015 11:39:26 +0000 Received: by wief7 with SMTP id f7so30773935wie.0 for ; Fri, 01 May 2015 04:39:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=tSnizDqwbJMfP6L+N782D6U+6i7+dfQXxqw76Y/xCNI=; b=EuwerH3toBcSaXORvBjvWP6yBxAlsb84S8U8K0Swh1pAUdlPudOXn3Q5AzbOKrb/0M cghRussGkaFowSXv/ToGKcfSroGqW5EXxfmfAgZI3W7y6t5BtakLApk1NTPhs+VWDxOI LxW8TRK4z3sexSfHKAoJq4AlRYB5qd5YgOXkMmGgfyO2rr9uNPGi+BfQWl4JCfdo8G/1 eJZXAw0GBepdATae7TEe4WxxKoz2v5bAtUQWDiIrw44H3TqRGEJ42dxQ/Y3IKDOu6bI3 qPdNiPf7jdeTp/ItK7YOytSaGT87Vdf9ydKTPsOdgYoNAvQ8/IS7goRkVp3zaAt473YO vXAg== X-Gm-Message-State: ALoCoQkjGDNSKPmL/KWeR15gXNROwYff5MpZ//Buh0rga9j0wJQvUHpg5kb7i6Q3XDpKyksWJR+s MIME-Version: 1.0 X-Received: by 10.194.236.66 with SMTP id us2mr17706837wjc.54.1430480363360; Fri, 01 May 2015 04:39:23 -0700 (PDT) Received: by 10.28.4.204 with HTTP; Fri, 1 May 2015 04:39:23 -0700 (PDT) In-Reply-To: References: Date: Fri, 01 May 2015 11:39:00 -0000 Message-ID: Subject: Re: [PATCH, AArch64] Add Cortex-A53 erratum 843419 configure-time option From: Yvan Roux To: Marcus Shawcroft Cc: "gcc-patches@gcc.gnu.org" , Maxim Kuvyrkov , Richard Earnshaw , James Greenhalgh Content-Type: text/plain; charset=UTF-8 X-IsSubscribed: yes X-SW-Source: 2015-05/txt/msg00034.txt.bz2 Hi Marcus, (Sorry wanted to cc you in my first mail but seems that gmail prefers Maxim to Marcus ! ;) On 1 May 2015 at 13:11, Marcus Shawcroft wrote: > On 1 May 2015 at 10:11, Yvan Roux wrote: >> Hi all, >> >> As described in the thread bellow, there is a link-time workaround for >> an erratum (843419) of some early revision of Cortex-A53. Similarly >> to what was done for a previous erratum, this patch adds a new >> configure-time option --enable-fix-cortex-a53-843419 that pass down >> the linker option --fix-cortex-a53-843419. >> >> I haven't implemented flags to explicitly disable/enable it during >> compilation as it is only a linker workaround, but I can do it if you >> think it's necessary. > > Hi Yvan, > > In the case of the 835769 erratum, providing such GCC configury made > (some) sense because the workaround included both a GCC and an LD > component. GCC in effect needed the option to control GCC behaviour > aswell as LD behaviour. The same is not true of 843419. The net effect > of the proposed patch here is to provide a configure option in GCC to > change the default behaviour of LD, with no other purpose within GCC > itself. This seems rather bizarre to me. I would have thought that if > the sole objective is to change the default behaviour of LD, then > there should be configure time options on LD, rather than GCC. Yes indeed. > That said, I can also see that providing consistent behaviour across > these various work around configure options and consistent run time > options for the user will reduce confusion in the future, both for > folks building toolchains and for the folks using them. From this > perspective I think it would be better to go with this patch *and* > include the flags explicitly such the both of the current workaround > have equivalent configury behaviour and have equivalent user flags at > run time. Ok I'll add the -mfix-cortex-a53-843419 flags to be consistent. Cheers Yvan > Cheers > /Marcus > >> >> https://sourceware.org/ml/binutils-cvs/2015-04/msg00012.html >> >> Is it ok for trunk and/or branches ? >> >> Thanks, >> Yvan >> >> 2015-05-01 Yvan Roux >> >> * configure.ac: Add --enable-fix-cortex-a53-843419 option. >> * configure: Regenerate. >> * config/aarch64/aarch64-elf-raw.h (CA53_ERR_843419_SPEC): Define. >> (LINK_SPEC): Include CA53_ERR_843419_SPEC. >> * config/aarch64/aarch64-linux.h (CA53_ERR_843419_SPEC): Define. >> (LINK_SPEC): Include CA53_ERR_843419_SPEC. >> * doc/install.texi (aarch64*-*-*): Document >> new --enable-fix-cortex-a53-843419 option.