xref: /freebsd/lib/libc/gen/frexp.3 (revision 6137b5f7b8c183ee8806d79b3f1d8e5e3ddb3df3)
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32.Dd March 4, 2005
33.Dt FREXP 3
34.Os
35.Sh NAME
36.Nm frexp ,
37.Nm frexpf ,
38.Nm frexpl
39.Nd convert floating-point number to fractional and integral components
40.Sh LIBRARY
41.Lb libm
42.Sh SYNOPSIS
43.In math.h
44.Ft double
45.Fn frexp "double value" "int *exp"
46.Ft float
47.Fn frexpf "float value" "int *exp"
48.Ft long double
49.Fn frexpl "long double value" "int *exp"
50.Sh DESCRIPTION
51The
52.Fn frexp ,
53.Fn frexpf
54and
55.Fn frexpl
56functions break a floating-point number into a normalized
57fraction and an integral power of 2.
58They store the integer in the
59.Vt int
60object pointed to by
61.Fa exp .
62.Sh RETURN VALUES
63These functions return the value
64.Va x ,
65such that
66.Va x
67is a
68.Vt double
69with magnitude in the interval
70.Eo [ 1/2 , 1 Ec )
71or zero, and
72.Fa value
73equals
74.Va x
75times 2 raised to the power
76.Fa *exp .
77If
78.Fa value
79is zero, both parts of the result are zero.
80.Sh SEE ALSO
81.Xr ldexp 3 ,
82.Xr math 3 ,
83.Xr modf 3
84.Sh STANDARDS
85The
86.Fn frexp ,
87.Fn frexpf ,
88and
89.Fn frexpl
90functions conform to
91.St -isoC-99 .
92