From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa2.mentor.iphmx.com (esa2.mentor.iphmx.com [68.232.141.98]) by sourceware.org (Postfix) with ESMTPS id 565C83858C33 for ; Tue, 4 Oct 2022 15:54:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 565C83858C33 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mentor.com X-IronPort-AV: E=Sophos;i="5.95,158,1661846400"; d="scan'208";a="84175872" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa2.mentor.iphmx.com with ESMTP; 04 Oct 2022 07:54:29 -0800 IronPort-SDR: hc8C97YsIgQbzvSsKnXG5gi9iFC825YNs0DlIGPYwgVjPej5l97vDML/lJtkUl4dNQiIxEjDR8 hsXWyPeVP/6XFr0vDitpVz0wW56RTKBB/GBpTJ6aN8EasGUigrvcXAEUKjPugE1icrcHIL1hbz n4+D3wJNAQPMrxV4rGhWnXYbOm++0QhcXbxB+el6Pfhj/xPydjPsAhAGhGzetqJj5ek1L3kaF9 uO6fv7NDs0cpcyiMd5DthOLw3sVcUOyVAEELv5dzlMTHTl+aMZsq9aB5VWXUIQwG9kZScjs7JP P+M= Date: Tue, 4 Oct 2022 15:54:23 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Jakub Jelinek CC: Jason Merrill , Richard Biener , Jeff Law , Uros Bizjak , Subject: Re: [PATCH] middle-end, c++, i386, libgcc: std::bfloat16_t and __bf16 arithmetic support In-Reply-To: Message-ID: References: <37522634-319a-b471-aa35-87e711b0479e@redhat.com> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: svr-ies-mbx-10.mgc.mentorg.com (139.181.222.10) To svr-ies-mbx-10.mgc.mentorg.com (139.181.222.10) X-Spam-Status: No, score=-3110.9 required=5.0 tests=BAYES_00,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Tue, 4 Oct 2022, Jakub Jelinek via Gcc-patches wrote: > Yet another problem is because I've only enabled the bf16/BF16 suffixes in > C++ because for C it might clash with some later extension. Am I right to > fear about that, or do you think C will never standardize suffixes that > would clash with that because C++ standardized the bf16/BF16 suffixes for > something already? If I could enable it, I'd always pedwarn for C for those I think any C proposal to standardize something conflicting with C++ would get objections from the WG21 liaison. > Another question is the suffixes of the builtins. For now I have added > bf16 suffix and enabled the builtins with !both_p, so one always needs to > use __builtin_* form for them. None of the GCC builtins end with b, > so this isn't ambiguous with __builtin_*f16, but some libm functions do end > with b, in particular ilogb, logb and f{??,??x}sub. ilogb and the subs > always have it, but is __builtin_logbf16 f16 suffixed logb or bf16 suffixed > log? Shall the builtins use f16b suffixes instead like the mangling does? Indeed, that conflict means bf16 isn't suitable for the built-in function suffix. -- Joseph S. Myers joseph@codesourcery.com