Annotation of src/lib/libc/gen/signbit.3, Revision 1.2
1.2 ! wiz 1: .\" $NetBSD: signbit.3,v 1.1 2004/01/15 19:43:45 kleink Exp $
1.1 kleink 2: .\"
3: .\" Copyright (c) 2003 The NetBSD Foundation, Inc.
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7: .\" by Klaus Klein.
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37: .Dd October 29, 2003
38: .Dt SIGNBIT 3
39: .Os
40: .Sh NAME
41: .Nm signbit
42: .Nd test sign
43: .Sh LIBRARY
44: .Lb libc
45: .Sh SYNOPSIS
46: .In math.h
47: .Ft int
48: .Fn signbit "real-floating x"
49: .Sh DESCRIPTION
50: The
51: .Fn signbit
52: macro determines whether the sign of its argument value
53: .Fa x
54: is negative.
55: An argument represented in a format wider than its semantic type is
56: converted to its semantic type first.
57: The determination is then based on the type of the argument.
58: .Ss IEEE754
1.2 ! wiz 59: The sign is determined for all values, including infinities, zeroes,
1.1 kleink 60: and NaNs
61: .Ss VAX
62: The sign is determined for finites, true zeros, and dirty zeroes;
63: for ROPs the sign is reported negative.
64: .Sh RETURN VALUES
65: The
66: .Fn signbit
67: macro returns a non-zero value if the sign of its value
68: .Fa x
69: is negative.
70: Otherwise 0 is returned.
71: .Sh ERRORS
72: No errors are defined.
73: .Sh SEE ALSO
74: .Xr fpclassify 3 ,
75: .Xr isfinite 3 ,
76: .Xr isnormal 3 ,
77: .Xr math 3
78: .Sh STANDARDS
79: The
80: .Fn signbit
81: macro conforms to
82: .St -isoC-99 .
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