From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x535.google.com (mail-pg1-x535.google.com [IPv6:2607:f8b0:4864:20::535]) by sourceware.org (Postfix) with ESMTPS id F3B663858D35 for ; Sun, 20 Feb 2022 11:58:11 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org F3B663858D35 Received: by mail-pg1-x535.google.com with SMTP id p23so11895580pgj.2 for ; Sun, 20 Feb 2022 03:58:11 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=QprNDuWN5s6wb4vPqP6UEbK8r/Xkz3cmxvTng7F4wko=; b=b2vSGu39CAZE4VV3tSpVj1+swmT9Vkmf/WQw7FR1DDQCD7ijrElw4wZQ+sO2B6jQ7Q 6LQNG68GvPkpNwwaIMbSrMF8Be3NeO1zPbODonlOnuP2fWPEnXm7LJJ1QL25CtskAM8W KgmmDrIz+V4GjaKxjpDaHiF84bI0T90WDcY2pyutQKQDq3NS/6ZcILwhWy55UgvCXxYS Oc60DiGufPs+bAMNZ7+DRK7cpF49snwlYXQSWZnhWnf+6jRS5aQAkgfhtE/ntJLXKxsE eFPLRoYZxshlZ4hO+WJXG9LlFbo7XdAUqTUEE1aHDC+4yi+emjLF6LlkkFNjY2YOBKyp iLTQ== X-Gm-Message-State: AOAM532QiQf1smcyV4P4NAoyhldxeX/IqK7AKQiEdhnuPN2hRbBuPttO AxlXK3Ih/zOsQxKMU+criRc= X-Google-Smtp-Source: ABdhPJwOSyY5nb6uOK+9mAQfKs/YuKF0XnsxH1aOvzqke6PBdj+5X+cyWKbisr2jfap1ph7YYTW1QA== X-Received: by 2002:a62:1555:0:b0:4e0:f0fb:654b with SMTP id 82-20020a621555000000b004e0f0fb654bmr15477376pfv.35.1645358291023; Sun, 20 Feb 2022 03:58:11 -0800 (PST) Received: from squeak.grove.modra.org (158.106.96.58.static.exetel.com.au. [58.96.106.158]) by smtp.gmail.com with ESMTPSA id v12sm15180293pgr.68.2022.02.20.03.58.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 20 Feb 2022 03:58:10 -0800 (PST) Received: by squeak.grove.modra.org (Postfix, from userid 1000) id CE2761140F2C; Sun, 20 Feb 2022 22:28:06 +1030 (ACDT) Date: Sun, 20 Feb 2022 22:28:06 +1030 From: Alan Modra To: Peter Bergner Cc: Waldemar Brodkorb , binutils@sourceware.org Subject: Re: regression with binutils 2.28 for ppc Message-ID: References: <8b8a3144-5c59-786f-a2ba-6f8813d60845@linux.ibm.com> <1f433717-0b26-4c53-6f21-9efeab7dcdc7@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1f433717-0b26-4c53-6f21-9efeab7dcdc7@linux.ibm.com> X-Spam-Status: No, score=-3031.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: binutils@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Binutils mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 20 Feb 2022 11:58:13 -0000 On Thu, Feb 17, 2022 at 10:21:30PM -0600, Peter Bergner wrote: > On 2/17/22 7:34 PM, Alan Modra wrote: > > On Thu, Feb 17, 2022 at 02:03:24PM -0600, Peter Bergner wrote: > >> The use of those ptesyncs in the kernel really needs to be audited though! > >> If they are legitimate, then the inline assembler needs to wrap their > >> use with ".machine push ; .machine ppc64 ; ptesync ; .machine pop". > > > > Right. Or we should allow the user command line to control the > > assembler, even with -Wa,-many if they so desire. But that's killed > > by that stupid .machine from gcc. > > I thought we were moving towards more reliance on .machine and not away > from it? You think we shouldn't be? I thought it wasn't a great idea when we started using it in 2015 or so. You can probably find archived email of me saying that. ;-) Nothing has changed since then to make me think that gcc controlling the assembler by both command-line options and a source directive at the start of assembly is a good idea. I'm tempted to hack gas to ignore the first .machine from gcc, if no code has been emitted and the .machine is a subset of what is given by the command line. > This is probably the difference between new gccs emiting .machine ppc64 > when using -mcpu=powerpc64 and old gccs that emit .machine ppc. Ah, gcc pr101393 (which was about 403, but same thing, .machine ppc rather than the correct machine). > Given all the above though, I'm surprised the kernel team hasn't hit > this already and complained to us about it! :-) I guess the focus has been on 64-bit kernels. -- Alan Modra Australia Development Lab, IBM