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34.Dd $Mdocdate: June 5 2013 $
35.Dt LDEXP 3
36.Os
37.Sh NAME
38.Nm ldexp ,
39.Nm ldexpf ,
40.Nm ldexpl
41.Nd multiply floating-point number by integral power of 2
42.Sh SYNOPSIS
43.In math.h
44.Ft double
45.Fn ldexp "double x" "int exp"
46.Ft float
47.Fn ldexpf "float x" "int exp"
48.Ft long double
49.Fn ldexpl "long double x" "int exp"
50.Sh DESCRIPTION
51The
52.Fn ldexp
53function multiplies a floating-point number by an integral
54power of 2.
55The
56.Fn ldexpf
57function is a single precision version of
58.Fn ldexp .
59The
60.Fn ldexpl
61function is an extended precision version of
62.Fn ldexp .
63.Sh RETURN VALUES
64The
65.Fn ldexp ,
66.Fn ldexpf
67and
68.Fn ldexpl
69functions return the value of
70.Fa x
71times 2 raised to the power
72.Fa exp .
73.Pp
74If the resultant value would cause an overflow,
75the global variable
76.Va errno
77is set to
78.Er ERANGE
79and the value
80.Dv HUGE
81is returned.
82.Sh SEE ALSO
83.Xr frexp 3 ,
84.Xr modf 3
85.Sh STANDARDS
86The
87.Fn ldexp
88function conforms to
89.St -ansiC .
90