xref: /freebsd/lib/libc/gen/frexp.3 (revision 2008043f386721d58158e37e0d7e50df8095942d)
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32.\"     @(#)frexp.3	8.1 (Berkeley) 6/4/93
33.\"
34.Dd March 4, 2005
35.Dt FREXP 3
36.Os
37.Sh NAME
38.Nm frexp ,
39.Nm frexpf ,
40.Nm frexpl
41.Nd convert floating-point number to fractional and integral components
42.Sh LIBRARY
43.Lb libm
44.Sh SYNOPSIS
45.In math.h
46.Ft double
47.Fn frexp "double value" "int *exp"
48.Ft float
49.Fn frexpf "float value" "int *exp"
50.Ft long double
51.Fn frexpl "long double value" "int *exp"
52.Sh DESCRIPTION
53The
54.Fn frexp ,
55.Fn frexpf
56and
57.Fn frexpl
58functions break a floating-point number into a normalized
59fraction and an integral power of 2.
60They store the integer in the
61.Vt int
62object pointed to by
63.Fa exp .
64.Sh RETURN VALUES
65These functions return the value
66.Va x ,
67such that
68.Va x
69is a
70.Vt double
71with magnitude in the interval
72.Eo [ 1/2 , 1 Ec )
73or zero, and
74.Fa value
75equals
76.Va x
77times 2 raised to the power
78.Fa *exp .
79If
80.Fa value
81is zero, both parts of the result are zero.
82.Sh SEE ALSO
83.Xr ldexp 3 ,
84.Xr math 3 ,
85.Xr modf 3
86.Sh STANDARDS
87The
88.Fn frexp ,
89.Fn frexpf ,
90and
91.Fn frexpl
92functions conform to
93.St -isoC-99 .
94