1*2fe8fb19SBen Gras.\" $NetBSD: signbit.3,v 1.3 2008/04/30 13:10:50 martin Exp $ 2*2fe8fb19SBen Gras.\" 3*2fe8fb19SBen Gras.\" Copyright (c) 2003 The NetBSD Foundation, Inc. 4*2fe8fb19SBen Gras.\" All rights reserved. 5*2fe8fb19SBen Gras.\" 6*2fe8fb19SBen Gras.\" This code is derived from software contributed to The NetBSD Foundation 7*2fe8fb19SBen Gras.\" by Klaus Klein. 8*2fe8fb19SBen Gras.\" 9*2fe8fb19SBen Gras.\" Redistribution and use in source and binary forms, with or without 10*2fe8fb19SBen Gras.\" modification, are permitted provided that the following conditions 11*2fe8fb19SBen Gras.\" are met: 12*2fe8fb19SBen Gras.\" 1. Redistributions of source code must retain the above copyright 13*2fe8fb19SBen Gras.\" notice, this list of conditions and the following disclaimer. 14*2fe8fb19SBen Gras.\" 2. Redistributions in binary form must reproduce the above copyright 15*2fe8fb19SBen Gras.\" notice, this list of conditions and the following disclaimer in the 16*2fe8fb19SBen Gras.\" documentation and/or other materials provided with the distribution. 17*2fe8fb19SBen Gras.\" 18*2fe8fb19SBen Gras.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19*2fe8fb19SBen Gras.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20*2fe8fb19SBen Gras.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21*2fe8fb19SBen Gras.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22*2fe8fb19SBen Gras.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23*2fe8fb19SBen Gras.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24*2fe8fb19SBen Gras.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25*2fe8fb19SBen Gras.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26*2fe8fb19SBen Gras.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27*2fe8fb19SBen Gras.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28*2fe8fb19SBen Gras.\" POSSIBILITY OF SUCH DAMAGE. 29*2fe8fb19SBen Gras.\" 30*2fe8fb19SBen Gras.Dd October 29, 2003 31*2fe8fb19SBen Gras.Dt SIGNBIT 3 32*2fe8fb19SBen Gras.Os 33*2fe8fb19SBen Gras.Sh NAME 34*2fe8fb19SBen Gras.Nm signbit 35*2fe8fb19SBen Gras.Nd test sign 36*2fe8fb19SBen Gras.Sh LIBRARY 37*2fe8fb19SBen Gras.Lb libc 38*2fe8fb19SBen Gras.Sh SYNOPSIS 39*2fe8fb19SBen Gras.In math.h 40*2fe8fb19SBen Gras.Ft int 41*2fe8fb19SBen Gras.Fn signbit "real-floating x" 42*2fe8fb19SBen Gras.Sh DESCRIPTION 43*2fe8fb19SBen GrasThe 44*2fe8fb19SBen Gras.Fn signbit 45*2fe8fb19SBen Grasmacro determines whether the sign of its argument value 46*2fe8fb19SBen Gras.Fa x 47*2fe8fb19SBen Grasis negative. 48*2fe8fb19SBen GrasAn argument represented in a format wider than its semantic type is 49*2fe8fb19SBen Grasconverted to its semantic type first. 50*2fe8fb19SBen GrasThe determination is then based on the type of the argument. 51*2fe8fb19SBen Gras.Ss IEEE754 52*2fe8fb19SBen GrasThe sign is determined for all values, including infinities, zeroes, 53*2fe8fb19SBen Grasand NaNs 54*2fe8fb19SBen Gras.Ss VAX 55*2fe8fb19SBen GrasThe sign is determined for finites, true zeros, and dirty zeroes; 56*2fe8fb19SBen Grasfor ROPs the sign is reported negative. 57*2fe8fb19SBen Gras.Sh RETURN VALUES 58*2fe8fb19SBen GrasThe 59*2fe8fb19SBen Gras.Fn signbit 60*2fe8fb19SBen Grasmacro returns a non-zero value if the sign of its value 61*2fe8fb19SBen Gras.Fa x 62*2fe8fb19SBen Grasis negative. 63*2fe8fb19SBen GrasOtherwise 0 is returned. 64*2fe8fb19SBen Gras.Sh ERRORS 65*2fe8fb19SBen GrasNo errors are defined. 66*2fe8fb19SBen Gras.Sh SEE ALSO 67*2fe8fb19SBen Gras.Xr fpclassify 3 , 68*2fe8fb19SBen Gras.Xr isfinite 3 , 69*2fe8fb19SBen Gras.Xr isnormal 3 , 70*2fe8fb19SBen Gras.Xr math 3 71*2fe8fb19SBen Gras.Sh STANDARDS 72*2fe8fb19SBen GrasThe 73*2fe8fb19SBen Gras.Fn signbit 74*2fe8fb19SBen Grasmacro conforms to 75*2fe8fb19SBen Gras.St -isoC-99 . 76