From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18386 invoked by alias); 29 Apr 2013 14:53:17 -0000 Mailing-List: contact libc-ports-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: libc-ports-owner@sourceware.org Received: (qmail 18361 invoked by uid 89); 29 Apr 2013 14:53:17 -0000 X-Spam-SWARE-Status: No, score=-8.6 required=5.0 tests=AWL,BAYES_00,KHOP_THREADED,RCVD_IN_HOSTKARMA_W,RCVD_IN_HOSTKARMA_WL,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.1 X-Spam-User: qpsmtpd, 2 recipients Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.84/v0.84-167-ge50287c) with ESMTP; Mon, 29 Apr 2013 14:53:11 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r3TEr25N024407 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 29 Apr 2013 10:53:02 -0400 Received: from zebedee.pink ([10.3.113.10]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r3TEr06j011678; Mon, 29 Apr 2013 10:53:01 -0400 Message-ID: <517E894C.8090602@redhat.com> Date: Mon, 29 Apr 2013 14:53:00 -0000 From: Andrew Haley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 MIME-Version: 1.0 To: =?UTF-8?B?T25kxZllaiBCw61sa2E=?= CC: "Joseph S. Myers" , Siddhesh Poyarekar , libc-alpha@sourceware.org, libc-ports@sourceware.org Subject: Re: [PATCH][BZ #14412] Define __sincos_finite as a fast version of sincos References: <20130429102739.GE1330@spoyarek.pnq.redhat.com> <20130429141553.GC24033@domone.kolej.mff.cuni.cz> In-Reply-To: <20130429141553.GC24033@domone.kolej.mff.cuni.cz> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-SW-Source: 2013-04/txt/msg00109.txt.bz2 On 04/29/2013 03:15 PM, Ondřej Bílka wrote: > On Mon, Apr 29, 2013 at 01:34:42PM +0000, Joseph S. Myers wrote: >> On Mon, 29 Apr 2013, Siddhesh Poyarekar wrote: >> >>> This patch brings back the assembly implementation of sincos (with >>> some changes) to give a fast alternative to the default sincos >>> implementation. This is defined as __sincos_finite and is used if the >>> implementing program is compiled with the -ffinite-math-only gcc flag. >> >> The changes don't seem to include accurate range reduction. Without that, >> I think this is inappropriate, as it will result in wildly inaccurate >> results for large but finite inputs. >> > These inputs contain zero significant digits. You cannot expect any > accuracty from them. You can't possibly know that. If the caller asks for sin(2^80) you should return a close approximation to sin(2^80), not garbage. Andrew.