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 07E8238708C3 for ; Tue, 1 Sep 2020 17:31:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 07E8238708C3 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=joseph_myers@mentor.com IronPort-SDR: 7qvYlbztcy5z3L3RisOnQbaYJk4I2XiLh1W/RZBBoJzZ4zfmu4x6z/cmf37nuDmj1txfpBA0zp XUCAPhR9wnV2FKYnWWUuu6zHj6J6zVR3oKfo1t1FolKQQFGDtllodf9kfN2c6Tn0sjrqi3Ky21 jwNqkSL1Eb83pRKvVQkNWI4Si2hEIU1awdiAin8RWTUkZTdxbf9upA8xEL4zjoyXgzm+G6QDTo x7GvxM+JprZN0V0eQYxAVWKRQqtkTVWKAGp3MNuoFSDyOxhaZnYKlhko/H4JhgtRTUYbWVrwEz nx8= X-IronPort-AV: E=Sophos;i="5.76,379,1592899200"; d="scan'208";a="52489778" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa2.mentor.iphmx.com with ESMTP; 01 Sep 2020 09:31:33 -0800 IronPort-SDR: kdmOie0XtcuF7icEIIoKNxN/Q9+89xqE1Vx5fBdA0ZgIdqSnyTlYHweVbucrKYL2KT4JGWbEKf 73P24LiTWOmw5xdbykgoh81z2QFHDob0aDA3cvclkCmGOq+H0nEwLtI1UTHwSY2w+jVaRhtoxe 4F1QCP5MnYQWenElcy0QmXj/AbfFpYBQSBIhtl64bJjwit7JO72BytfPbkQazBVhqoeTaiv1md A0j2eskwr+VeomM+zazhiozHdGrQjuUj0U5Gv5INZuGlbYJAM/1wQ1KtPaeptlUFvEJALQxobo mLg= Date: Tue, 1 Sep 2020 17:31:27 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Tulio Magno Quites Machado Filho CC: Matheus Castanho , Carlos O'Donell , Adhemerval Zanella , Subject: Re: [PATCH] Update powerpc libm-test-ulps In-Reply-To: <87eenmaey3.fsf@linux.ibm.com> Message-ID: References: <20200820183700.115087-1-msc@linux.ibm.com> <076cd0b3-1988-144f-3c25-cc71a14218c2@redhat.com> <1efa0451-3df4-73ee-93e3-934f6ff1a30d@linaro.org> <875z9dgl0w.fsf@linux.ibm.com> <8da995b5-db39-b306-56e7-693c864a824e@redhat.com> <06271a7e-e3fa-35eb-d045-04b2711c8b5c@linux.ibm.com> <87eenmaey3.fsf@linux.ibm.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: SVR-IES-MBX-04.mgc.mentorg.com (139.181.222.4) To SVR-IES-MBX-03.mgc.mentorg.com (139.181.222.3) X-Spam-Status: No, score=-3127.6 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Sep 2020 17:31:35 -0000 On Mon, 31 Aug 2020, Tulio Magno Quites Machado Filho via Libc-alpha wrote: > > 2. Do (1) only for entries that have ULPs higher than a threshold (say, > > 9 or 16)? > > Likewise, if we're able to keep maximum ULPs at 9 without marking too many tests > as xfail'ed, that's better. > Per the contents of sysdeps/powerpc/fpu/libm-test-ulps, this should be possible > and would not need have a greater max_valid_error for inexact functions just > for ibm128. If the functions for different floating-point formats use similar algorithms, the error may be a multiple of the error for the basic arithmetic operations. Since the basic arithmetic operations for ldbl-128ibm are less accurate than for IEEE formats, it seems reasonable to allow larger errors for libm functions for that format as well. Ideally the errors would be smaller than they are for some functions with larger errors, but that might require algorithmic improvements. The existing bounds of 9 or 16 ulps are empirical, based on what's seen with functions where the issue is simply the accumulation of lots of separate errors rather than algorithms with inherent numerical problems. -- Joseph S. Myers joseph@codesourcery.com