xref: /netbsd/lib/libc/gen/fpclassify.3 (revision 6550d01e)
1.\"	$NetBSD: fpclassify.3,v 1.3 2008/04/30 13:10:50 martin Exp $
2.\"
3.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
4.\" All rights reserved.
5.\"
6.\" This code is derived from software contributed to The NetBSD Foundation
7.\" by Klaus Klein.
8.\"
9.\" Redistribution and use in source and binary forms, with or without
10.\" modification, are permitted provided that the following conditions
11.\" are met:
12.\" 1. Redistributions of source code must retain the above copyright
13.\"    notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\"    notice, this list of conditions and the following disclaimer in the
16.\"    documentation and/or other materials provided with the distribution.
17.\"
18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28.\" POSSIBILITY OF SUCH DAMAGE.
29.\"
30.Dd January 14, 2004
31.Dt FPCLASSIFY 3
32.Os
33.Sh NAME
34.Nm fpclassify
35.Nd classify real floating type
36.Sh LIBRARY
37.Lb libc
38.Sh SYNOPSIS
39.In math.h
40.Ft int
41.Fn fpclassify "real-floating x"
42.Sh DESCRIPTION
43The
44.Fn fpclassify
45macro performs classification of its argument
46.Fa x .
47An argument represented in a format wider than its semantic type is
48converted to its semantic type first.
49The classification is then based on the type of the argument.
50.Ss IEEE 754
51.Bl -tag -width "FP_SUBNORMALXXX" -compact -offset indent
52.It Dv FP_INFINITE
53infinity, either positive or negative
54.It Dv FP_NAN
55not-a-number
56.Pq Dq NaN
57.It Dv FP_NORMAL
58normal
59.It Dv FP_SUBNORMAL
60subnormal
61.It Dv FP_ZERO
62zero
63.El
64.Ss VAX
65.Bl -tag -width "FP_DIRTYZEROXXX" -compact -offset indent
66.It Dv FP_ROP
67reserved operand
68.Pq Dq ROP
69.It Dv FP_DIRTYZERO
70dirty zero
71.It Dv FP_NORMAL
72finite
73.It Dv FP_ZERO
74true zero
75.El
76.Sh RETURN VALUES
77The
78.Fn fpclassify
79macro returns the value of the number classification macro appropriate
80to its argument
81.Fa x
82as described above.
83.Sh ERRORS
84No errors are defined.
85.Sh SEE ALSO
86.Xr isfinite 3 ,
87.Xr isnormal 3 ,
88.Xr math 3 ,
89.Xr signbit 3
90.Sh STANDARDS
91The
92.Fn fpclassify
93macro conforms to
94.St -isoC-99 .
95