From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 105175 invoked by alias); 5 Dec 2017 10:24:31 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 105071 invoked by uid 89); 5 Dec 2017 10:24:19 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: EUR01-HE1-obe.outbound.protection.outlook.com Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=Szabolcs.Nagy@arm.com; Message-ID: <5A2673C4.5050809@arm.com> Date: Tue, 05 Dec 2017 10:24:00 -0000 From: Szabolcs Nagy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: "H.J. Lu" , Carlos O'Donell CC: nd@arm.com, GNU C Library Subject: Re: [PATCH] x86-64: Use direct TLS initial-exec access to update errno References: <20171204231315.GA17402@intel.com> <755bd730-80d2-018e-f583-ff2b661a046e@redhat.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: LNXP265CA0035.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:5c::23) To HE1PR0802MB2489.eurprd08.prod.outlook.com (2603:10a6:3:d8::23) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 8d57fc2a-a0e5-4b17-0f52-08d53bca510c X-MS-Office365-Filtering-HT: Tenant X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(5600026)(4604075)(4534020)(4602075)(4627115)(201703031133081)(201702281549075)(48565401081)(2017052603286);SRVR:HE1PR0802MB2489; X-Microsoft-Exchange-Diagnostics: 1;HE1PR0802MB2489;3:qtPYQiaCm+RXtvT2ajtUCF5WA9dB1N4jpSPwQhsUfko7NZ8XRMWUnnmt8zVcytjPQtuMQ8S4gKBHRmVU2987BezMckb2Xj1RooNTkNsHz8GtaWKCDZoMQ3VQixHJ+MfSO9kl//DmqPafr42GWWWKgTwL1jfzJ8xEm7rHOAWhf5bonbVwisnxL7KfdzIkO2cWQKI4PNpPtruD+CbWkkhrv8NY6m0o7FX23DB/VYEhIIXKPIMCOHTbP/HAhf/sQMtN;25:eWKfb0p0evZcq3KRk1KMUwTidbz/ovxlkrFikef4JdQYXcH5SjQD6iltrboeLA7g7ZZg3iDW+XRY9iKuxvZW6NlCzKn6O8s22UTcuzGzaFYooELyDBeqdk1jVb5xMdok0rAEcX7mOXa37kXM94487oQ2+rd88DOYrO0cUyv3fLcalkYIelD20oqFAK3TPpzyYMc2qtBpMDdhGN+Ja6q7vZe4L5vAlu0TwDoKexT/wtN7xL91wVenrxRygWbc0hZh26/yJGMUvm6W5C3XEHLOFUBYPGX+ixIqNq0uy1e3stVVN4Qnnd36Us2/9v+AyU+uizT+KOSqnkF+GT4+4ofeCQ==;31:e1GoaPPJYndjC9iSd/IegW5aCqqhYlflHOtMD1tnjtHsHNIFsGuqxYdqulWi7Nk7t+YSSEb0c0KSD2wDCnHedy8rwBWky1wbiEVA3tDZOJ5GzN0YfpVIG/b2PSk8czWGHIQV7GFSYGUHnA2uVobPpYpqz3FN7lX4O3oehKqQvp/x1H2nA1T7ukFk0kwsnq3frvn8xmFjNHcwtFTqAOXNEj2TjpHxWewwvdxZV0OuuII= X-MS-TrafficTypeDiagnostic: HE1PR0802MB2489: NoDisclaimer: True X-Microsoft-Exchange-Diagnostics: 1;HE1PR0802MB2489;20:nHQZMIK52m26B/D5MIIC63VdSo20UqN26NdpA3044z4u2WldZYjkl0X4bkSzJ6zNzvMf3jxqyvORNLjL1LRunqHKTWMTwIqW2TKgZSJHFvy81yHkfKogLFHnVjMURESejb1Iu4vczY9EcmILIM3B+qXnCkBEzOy5EMFWb55QuUk=;4:UFLx9KfDQntgxZ4aW9YYIzHnnvP8B2RA1TGL4iMMxv2jNpCu94q1Rp1PVYTafNOnfV8Ofw0FXxcKQA2qI2TPVFHMbzhJEfO2lkisK57Z84XMJu22NYTk5EFW0q5G7z+gA3jIaiuu+IEkiRuD6df5xZjXudsxiP+bW6DRzCJ5Oeweh8fwRtYDK79sugOoP9i9Wfrz9Zq86T2eT0MmBf3MYL+rjK32wXE5Yc2hgQdZX59Qsyu6NA1KZumx0jMNaQ0w7qbnGy7qhFEPz7feHi/elw== X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; 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Lu wrote: > On Mon, Dec 4, 2017 at 3:33 PM, Carlos O'Donell wrote: >> Why make these changes? > > It is motivated by > > https://sourceware.org/ml/libc-alpha/2017-12/msg00101.html > the failure paths of math functions are not performance critical, ideally there should be no errno access at all just a tail call to something like __math_invalidf (see flt-32/math_errf.c): reduces code size and does all error handling at a single place without tls abi dependent code in asm.