xref: /freebsd/lib/libc/gen/frexp.3 (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
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32.\"     @(#)frexp.3	8.1 (Berkeley) 6/4/93
33.\" $FreeBSD$
34.\"
35.Dd March 4, 2005
36.Dt FREXP 3
37.Os
38.Sh NAME
39.Nm frexp ,
40.Nm frexpf ,
41.Nm frexpl
42.Nd convert floating-point number to fractional and integral components
43.Sh LIBRARY
44.Lb libm
45.Sh SYNOPSIS
46.In math.h
47.Ft double
48.Fn frexp "double value" "int *exp"
49.Ft float
50.Fn frexpf "float value" "int *exp"
51.Ft long double
52.Fn frexpl "long double value" "int *exp"
53.Sh DESCRIPTION
54The
55.Fn frexp ,
56.Fn frexpf
57and
58.Fn frexpl
59functions break a floating-point number into a normalized
60fraction and an integral power of 2.
61They store the integer in the
62.Vt int
63object pointed to by
64.Fa exp .
65.Sh RETURN VALUES
66These functions return the value
67.Va x ,
68such that
69.Va x
70is a
71.Vt double
72with magnitude in the interval
73.Eo [ 1/2 , 1 Ec )
74or zero, and
75.Fa value
76equals
77.Va x
78times 2 raised to the power
79.Fa *exp .
80If
81.Fa value
82is zero, both parts of the result are zero.
83.Sh SEE ALSO
84.Xr ldexp 3 ,
85.Xr math 3 ,
86.Xr modf 3
87.Sh STANDARDS
88The
89.Fn frexp ,
90.Fn frexpf ,
91and
92.Fn frexpl
93functions conform to
94.St -isoC-99 .
95