From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 34428 invoked by alias); 4 Jan 2017 11:25:28 -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 34410 invoked by uid 89); 4 Jan 2017 11:25:26 -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,RCVD_IN_DNSWL_NONE,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy=hassle, HTo:U*uweigand, HX-MS-Exchange-CrossTenant-OriginalArrivalTime:2017, HX-MS-Exchange-CrossTenant-OriginalArrivalTime:Jan X-HELO: EUR01-HE1-obe.outbound.protection.outlook.com Received: from mail-he1eur01on0085.outbound.protection.outlook.com (HELO EUR01-HE1-obe.outbound.protection.outlook.com) (104.47.0.85) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 04 Jan 2017 11:25:16 +0000 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=Szabolcs.Nagy@arm.com; Received: from [10.2.206.73] (217.140.96.140) by DB6PR0802MB2488.eurprd08.prod.outlook.com (10.172.251.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.817.10; Wed, 4 Jan 2017 11:25:12 +0000 Message-ID: <586CDB95.9000909@arm.com> Date: Wed, 04 Jan 2017 11:25:00 -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: Segher Boessenkool , Ulrich Weigand CC: , Torvald Riegel , Gabriel Paubert , "Bin Fan@Work" , "gcc@gcc.gnu.org" , , Subject: Re: GCC libatomic ABI specification draft References: <58593903.4020508@arm.com> <20161222142856.C5B931032A2@oc8523832656.ibm.com> <20161222173747.GK11295@gate.crashing.org> In-Reply-To: <20161222173747.GK11295@gate.crashing.org> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: AM4PR0202CA0011.eurprd02.prod.outlook.com (10.171.80.21) To DB6PR0802MB2488.eurprd08.prod.outlook.com (10.172.251.23) X-MS-Office365-Filtering-Correlation-Id: beddd0e4-d3ad-4bd8-64cf-08d4349459d0 X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001);SRVR:DB6PR0802MB2488; X-Microsoft-Exchange-Diagnostics: 1;DB6PR0802MB2488;3:G61aOTSBymBdADViXgnWfcGdOpgEvU0+jvUQHcARTv/vDhX0LZfffRM5dgP0KK4RAEOcMpwX7HN9zF4sC7vQUh2ROzJU8IRXqB92i4XIa1YCjSudJwL0PcwWS7RynUCyhMLU2IrofSXuH3vQsldmgzoSPQWPeUZvWyjR5zrJUHm/xuIWQaMAwsmHTV/DWYrnWjZc5ySZdYVprTr08/WQLutJDfWwEP1UMWcq7Rlqk27+wipf8KfS5+LLmTEUw6j6J1ZXqABQvddqthz6FENn7A==;25:TjVs75Yo5Ay+C8ur3YCYnyOL/OxrOKBNgZi4bjlovaR4X96JlLR5WYhIH2ji0wgOBpn+VM3tnTGnOZcDimsKR7U/SXNEivSd0S3OiiAto9nGR7X8/fhocTA2TFBeHwICpJCkURgblvD2opjH+6q/EEsCyMRe0JKuArJdeAqdI4FMbtmEk41/vZ+s0aKuAmj/DQMrDiOhc+A+BArzgJata2lHpitu7xhhk846OPSMfhq2yoi3eO7f7HaMgxlvK/BRo3F3Qt8OqmrDK8n4IE2XDe4OswfenO2khXrPlo9EiPz8FmQupH+vMIkQXz4gY/ojyT4c/P2cEp3L8vAo5NfbGerWwtCQuXC6CC3aKeIqWxXOqjzknLUo952pKacWJmtYAdFUqTOs664rQzmmOpS10KKX96ImlpZpGmOqrG34FuwhCQ15dVUzeNP0BgGqKw5pbs2GyZDbzqdtW4SB5pA42g== X-Microsoft-Exchange-Diagnostics: 1;DB6PR0802MB2488;31:hnHHx6EICY8EJbaIhFI6o1xLUSYIfEb1BIOhvh2k5JIe0xR2eJ0Kb64JYBf7cy+gyQFvZtx3YIeArWzcR4kg+hOw/bRvx9v15ajdgP79McrKadS0L7viwBEjc6RUwcAEuqwelM100rXWH42oKqzdmY7SNDl9WXw6qWnabnY6bwe5keLLXmUxYh8bwpeSRX6JjmsrwQGF8CqepypcipyeOiZT0cYDLnhRx7BeQbdRhV+1uCP+2nl/ts9GMRgsO2E9;20:1wOG1jrIyMHE5AbUiGHsdpN5+8j5hvr7NqvEGEoE2OoqjiWKW2tEbVjccD326691/rjNO9C9rrvt6qC5dSzmI/qUFFZjKBVNEgod7GrZxz5AgZ/uy0yHl6/gqDOt4cxkXStcKQMxgcuzY0I6DVusSMThaVYXp3PVSzsn+oURjFo= NoDisclaimer: True X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(6040375)(601004)(2401047)(5005006)(8121501046)(3002001)(10201501046)(6055026)(6041248)(20161123560025)(20161123555025)(20161123562025)(20161123564025)(20161123558021)(6072148);SRVR:DB6PR0802MB2488;BCL:0;PCL:0;RULEID:;SRVR:DB6PR0802MB2488; X-Microsoft-Exchange-Diagnostics: 1;DB6PR0802MB2488;4: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 X-Forefront-PRVS: 0177904E6B X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10009020)(4630300001)(6049001)(6009001)(7916002)(39450400003)(39860400002)(39850400002)(39840400002)(39410400002)(24454002)(199003)(189002)(229853002)(86362001)(8676002)(50986999)(189998001)(54356999)(90366009)(50466002)(2906002)(65956001)(66066001)(65806001)(87266999)(39060400001)(77096006)(25786008)(76176999)(36756003)(65816999)(68736007)(92566002)(101416001)(38730400001)(5001770100001)(64126003)(106356001)(105586002)(6486002)(59896002)(81156014)(6666003)(4326007)(23746002)(83506001)(2950100002)(33656002)(81166006)(230700001)(3846002)(7736002)(80316001)(305945005)(6116002)(4001350100001)(5660300001)(97736004)(54906002)(42186005)(47776003);DIR:OUT;SFP:1101;SCL:1;SRVR:DB6PR0802MB2488;H:[10.2.206.73];FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; Received-SPF: None (protection.outlook.com: arm.com does not designate permitted sender hosts) X-Microsoft-Exchange-Diagnostics: =?Windows-1252?Q?1;DB6PR0802MB2488;23:1Fa8mKsYPe1DBZSE4vX9zGeV+2UvGZFk3K2?= =?Windows-1252?Q?OvyjGGe5fDxE9JLZ6aNUvUfzJQ8CDw7ezocJA7IW2LpkTEvrelU/8Oih?= =?Windows-1252?Q?hvjAYL59dFBb0/p98T68q9uQ5t7wgsGIdMLEZweyXDMuF/CVPEWARqft?= =?Windows-1252?Q?YsyVfV3PTLsv3oi3I2MuZ8FBog31PwItYlkBylHWem/0ZS0o1tMoGEl2?= =?Windows-1252?Q?dbZj0+bmw2HTnt2HK8gy7yCZqAiOSJR5Pd279eI/GpayRiMcwDvTyAJ3?= =?Windows-1252?Q?28Lk57QLiJzcclwAZPI4PQcPn3Xq42Jgu6t3nWCKs/SxtUpNZ1o1P7uZ?= =?Windows-1252?Q?pHOvUURGRswtmeOJGi5XjWTWRozoV9KJB35PEDiUqK1zt+hdobWTp0m8?= =?Windows-1252?Q?o/8u0FXPSgfGYxnK18JcqRtmCwzgDXji83nirvI7KS25myRq3gHRbcVP?= =?Windows-1252?Q?q/EXCGRn051vKT3mfzpbgAK3eq7PqZQ+NeptDzMu6hwjMkNj9d2Rg/OM?= =?Windows-1252?Q?EPGd2TwgXEQZX7uK104+ytAYHv9bFypitgJrPF8+SStU9UAaAmLB9RjQ?= =?Windows-1252?Q?fjMGBGRp1UGabelY/mw26w9GEa9Suzr+CPG9SQXBUufkRlde+uDWRLG6?= =?Windows-1252?Q?1J9GmDmybRJFrs4DrrZ6Jj9vbbFP97/+E4G7jLsMU3GzFB05CZ9TnTTz?= =?Windows-1252?Q?Eht7yVm3wDNSvfOzQCgxzBGTCLl1l341bz6H9uJk6i7pSadnHW1KKlLs?= =?Windows-1252?Q?sUoMRNCT8y1Os3mMOBsJRgBv2u6GK26QkOu/fZYHXeJ4zZL4QLP8KCJ7?= =?Windows-1252?Q?F3VZOPmGwIZ9yJlgGicELXw/Iq68/TR50faS2LoRCyybrb1c2QnrTi2y?= =?Windows-1252?Q?jkvcJpq02iuiO/L+zTdq9B1ZCGs631hals6atmgW4jEl0BLT1rHsJfJU?= =?Windows-1252?Q?KbqlzpkizKOL9FsNl7IrvqbpM9/HgqTwHQlpKU2SDZC/99sDk6h8CcPC?= =?Windows-1252?Q?DnHySen62Q/Iz6IL04YqktKyAJ9mHBW2LRIZggvcPDotNjmkuyCkjEpR?= =?Windows-1252?Q?MwYmtp1CqVwb0JqB4Ag26dqefwm7vaVp8GXQ1a/0s9i/BbnUzK1fOP44?= =?Windows-1252?Q?5Lqg8bxyeu7OLDv5wLXs2Ebg9zlCZoasXdeCS4Cztio3wmYVohMyp7v5?= =?Windows-1252?Q?5YtZ6KdlekG8TajqSTMw0h39+diHeJ3E4n7104gb5XxCVlo0gGzGwPwQ?= =?Windows-1252?Q?qgT/K86l+Umm0TJ212zQ7KK7t9CfFEMUWomOE5nNURxb3l68ymh8QDdJ?= =?Windows-1252?Q?Vo6LGecCLFABh4CYePEfRjyZX8P6q41wPbYDxGT/jny4rSVHfQFwj+Ls?= =?Windows-1252?Q?WpuPMoqbpZYLJO+qAZYW1JQRTlkLKeslOvU30ffvvN0MxA0iVcFDmjzc?= =?Windows-1252?Q?Zgc8ut5wBaOO6/WLYn9M1mTEJOL4wSEStq/vT7Wwoze8IzBvjJZe2xQv?= =?Windows-1252?Q?sqv+dLeAnGtCEZUau88pNkQxwgK1X2a2U1DLrMWKA+C6DxhLJ9Cieplu?= =?Windows-1252?Q?8rON9CaDLtxAbrNzosvKOnnlS9jLYBw1F1uFtKYQA4kKPenchw7NSvIg?= =?Windows-1252?Q?DUA=3D=3D?= X-Microsoft-Exchange-Diagnostics: 1;DB6PR0802MB2488;6:KZg5t6SPxAu/ppKXt/HmEbt2KSCpH5fsqeotiKfsjJP0j5DDke+OKOiD6yhMsmb17JqwdomTx4WDeGILOEWE8xeKqZzhennLvzQOpM12E9740zHFKEnM1zYmhWwsPbVydBZnQdNx69+hx/1bXP2kteIc4GO765rG2SIXjRuhlK+qDJi3eGdrXEVGDTJEk5MpF9l+a5QsZ6LrHOGA/+QNlvWe7dMcnRcDadrYjLEzwtDIg8LR+W4mfWoD/6khejdmkUdTqwvm5Ry6QDIDE3X5aK9d05SFD6qyNmnnM7ybEDBZa8b6o4uELJQolTuC5WMy+HmZ/kum6m4eBFu86F9dE7bwt/6pdorM0LxdL5H+cDtbdr0QuAsfDEQugExmx2RPdo4wYH3gZNbEPCv5sIHTkKidpz2DyHPrFwVQdk01yuYHp+fWuziPHvccvyjKQ27NgM332KZhK6xoY+/ox5YXZw==;5:tw0OBcgOwi3J0CycaFEO65U/MuaNYCRO+M/GL+DvFDyZjF0fnIo+wU4/80+t0NaNl1Byg4/J/zJ39NJLkDAqgbpQHZMqlsbmp8SaVWN1OOrqJPC9tSp22JKCksT7RO8fICfWYWS9iy1lbvhYuOa7CQ==;24:b/b5wSFuzZVnb1QCL72bhTpA0luhwiQCws6pJ7D/tY54pxD1xYIHZ90AmkBkD9cQVj/MmiWMwSeMAiOURdkaBjQR+ieu9p2UISijtQ0cS1Y= SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1;DB6PR0802MB2488;7:iev794X7/S4eoKV30DtqNfUE1+zveeLrBUlRgQheX2Hx8/EcpeJpxi9BzKldQTNVndhiMGfgRt3MpnokObICQ6nSpEzn1PjFcD1D/yQVwIADUaHVFBhzm0ZygwpVDHxXZ02bbwcNwNtVu6bcLJjD/6q+KLVw6DP9LVlAahfIFcRSwFPKYSX6R2GzmxdZgbtG871pPHMkI2CcZ/5aSY8wBszVE42ltazAxJejgOFw1aPqQ1mlAn+c4vCByceHpvrseBxtgIOZsTUcHhtHjDlc8myQXSZxVMmmiule2XpSzFlhK+8AFVu0ty3Ml4zKwkwxBOtADVPtgA9OblE4KxylZdkal0zScACtLU1fyjOed3MBoaVItSirU444gX+cZN7wysu2blygQDEs1wwxIc71kDkGOHl3GbdXCJxVTSoIWVj+jDfd1stdzV0RNMIPDv3cGpVtyS3dts9MacIP859uqA== X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Jan 2017 11:25:12.7301 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB6PR0802MB2488 X-IsSubscribed: yes X-SW-Source: 2017-01/txt/msg00020.txt.bz2 On 22/12/16 17:37, Segher Boessenkool wrote: > We do not always have all atomic instructions. Not all processors have > all, and it depends on the compiler flags used which are used. How would > libatomic know what compiler flags are used to compile the program it is > linked to? > > Sounds like a job for multilibs? x86_64 uses ifunc dispatch to always use atomic instructions if available (which is bad because ifunc is not supported on all platforms). either such runtime feature detection and dispatch is needed in libatomic or different abis have to be supported (with the usual hassle).