1*2fe8fb19SBen Gras.\" $NetBSD: isinf.3,v 1.12 2004/03/04 23:47:56 wiz Exp $ 2*2fe8fb19SBen Gras.\" 3*2fe8fb19SBen Gras.\" Copyright (c) 1991, 1993 4*2fe8fb19SBen Gras.\" The Regents of the University of California. All rights reserved. 5*2fe8fb19SBen Gras.\" 6*2fe8fb19SBen Gras.\" Redistribution and use in source and binary forms, with or without 7*2fe8fb19SBen Gras.\" modification, are permitted provided that the following conditions 8*2fe8fb19SBen Gras.\" are met: 9*2fe8fb19SBen Gras.\" 1. Redistributions of source code must retain the above copyright 10*2fe8fb19SBen Gras.\" notice, this list of conditions and the following disclaimer. 11*2fe8fb19SBen Gras.\" 2. Redistributions in binary form must reproduce the above copyright 12*2fe8fb19SBen Gras.\" notice, this list of conditions and the following disclaimer in the 13*2fe8fb19SBen Gras.\" documentation and/or other materials provided with the distribution. 14*2fe8fb19SBen Gras.\" 3. Neither the name of the University nor the names of its contributors 15*2fe8fb19SBen Gras.\" may be used to endorse or promote products derived from this software 16*2fe8fb19SBen Gras.\" without specific prior written permission. 17*2fe8fb19SBen Gras.\" 18*2fe8fb19SBen Gras.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19*2fe8fb19SBen Gras.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20*2fe8fb19SBen Gras.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21*2fe8fb19SBen Gras.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22*2fe8fb19SBen Gras.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23*2fe8fb19SBen Gras.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24*2fe8fb19SBen Gras.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25*2fe8fb19SBen Gras.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26*2fe8fb19SBen Gras.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27*2fe8fb19SBen Gras.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28*2fe8fb19SBen Gras.\" SUCH DAMAGE. 29*2fe8fb19SBen Gras.\" 30*2fe8fb19SBen Gras.\" @(#)isinf.3 8.2 (Berkeley) 1/29/94 31*2fe8fb19SBen Gras.\" 32*2fe8fb19SBen Gras.Dd March 5, 2004 33*2fe8fb19SBen Gras.Dt ISINF 3 34*2fe8fb19SBen Gras.Os 35*2fe8fb19SBen Gras.Sh NAME 36*2fe8fb19SBen Gras.Nm isinf 37*2fe8fb19SBen Gras.Nd test for infinity 38*2fe8fb19SBen Gras.Sh LIBRARY 39*2fe8fb19SBen Gras.Lb libc 40*2fe8fb19SBen Gras.Sh SYNOPSIS 41*2fe8fb19SBen Gras.In math.h 42*2fe8fb19SBen Gras.Ft int 43*2fe8fb19SBen Gras.Fn isinf "real-floating x" 44*2fe8fb19SBen Gras.Sh DESCRIPTION 45*2fe8fb19SBen GrasThe 46*2fe8fb19SBen Gras.Fn isinf 47*2fe8fb19SBen Grasmacro determines whether its argument 48*2fe8fb19SBen Gras.Fa x 49*2fe8fb19SBen Grasis an infinity (positive or negative). 50*2fe8fb19SBen GrasAn argument represented in a format wider than its semantic type is 51*2fe8fb19SBen Grasconverted to its semantic type first. 52*2fe8fb19SBen GrasThe determination is then based on the type of the argument. 53*2fe8fb19SBen Gras.Ss IEEE 754 54*2fe8fb19SBen GrasIt is determined whether the value of 55*2fe8fb19SBen Gras.Fa x 56*2fe8fb19SBen Grasis an infinity. 57*2fe8fb19SBen Gras.Ss VAX 58*2fe8fb19SBen GrasInfinities are not supported. 59*2fe8fb19SBen Gras.Sh RETURN VALUES 60*2fe8fb19SBen GrasThe 61*2fe8fb19SBen Gras.Fn isinf 62*2fe8fb19SBen Grasmacro returns a non-zero value if the value of 63*2fe8fb19SBen Gras.Fa x 64*2fe8fb19SBen Grasis an infinity. 65*2fe8fb19SBen GrasOtherwise 0 is returned. 66*2fe8fb19SBen Gras.Sh SEE ALSO 67*2fe8fb19SBen Gras.Xr fpclassify 3 , 68*2fe8fb19SBen Gras.Xr isfinite 3 , 69*2fe8fb19SBen Gras.Xr isinff 3 , 70*2fe8fb19SBen Gras.Xr isnan 3 , 71*2fe8fb19SBen Gras.Xr isnanf 3 , 72*2fe8fb19SBen Gras.Xr isnormal 3 , 73*2fe8fb19SBen Gras.Xr math 3 , 74*2fe8fb19SBen Gras.Xr signbit 3 75*2fe8fb19SBen Gras.Rs 76*2fe8fb19SBen Gras.%T "IEEE Standard for Binary Floating-Point Arithmetic" 77*2fe8fb19SBen Gras.%Q ANSI 78*2fe8fb19SBen Gras.%R Std 754-1985 79*2fe8fb19SBen Gras.Re 80*2fe8fb19SBen Gras.Sh STANDARDS 81*2fe8fb19SBen GrasThe 82*2fe8fb19SBen Gras.Fn isinf 83*2fe8fb19SBen Grasmacro conforms to 84*2fe8fb19SBen Gras.St -isoC-99 . 85