From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22953 invoked by alias); 1 Oct 2009 09:52:39 -0000 Received: (qmail 22903 invoked by uid 48); 1 Oct 2009 09:52:24 -0000 Date: Thu, 01 Oct 2009 09:52:00 -0000 From: "zimmerma+gcc at loria dot fr" To: glibc-bugs@sources.redhat.com Message-ID: <20091001095223.10716.zimmerma+gcc@loria.fr> Reply-To: sourceware-bugzilla@sourceware.org Subject: [Bug math/10716] New: various problems in cacosh and cacos X-Bugzilla-Reason: CC Mailing-List: contact glibc-bugs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: glibc-bugs-owner@sourceware.org X-SW-Source: 2009-10/txt/msg00002.txt.bz2 The classical branch cut for cacosh() is (-inf, 1). However, cacosh() is using a different branch cut. For example (courtesy of Kaveh Ghazi): cacosh(-1 + -0 I) -> (0 + 3.14159265358979 I) With the classical branch cut, one would get (0 - 3.14159265358979 I). Also the sign of 0 is not always correct: cacos(1 + 0 I) -> (0 + 0 I) [should be (0 - O I)] Finally the documentation of cacosh says that the real part of the result is chosen non-negative, which is clearly wrong on this example: cacosh(-3.45677995681763 + -2.3456699848175 I) -> (-2.11780021549476 + 2.53187508681341 I) See for more details. -- Summary: various problems in cacosh and cacos Product: glibc Version: 2.10 Status: NEW Severity: normal Priority: P2 Component: math AssignedTo: aj at suse dot de ReportedBy: zimmerma+gcc at loria dot fr CC: glibc-bugs at sources dot redhat dot com GCC build triplet: x86_64-redhat-linux GCC host triplet: x86_64-redhat-linux GCC target triplet: x86_64-redhat-linux http://sourceware.org/bugzilla/show_bug.cgi?id=10716 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.