xref: /freebsd/lib/libc/gen/ldexp.3 (revision 641a6cfb86023499caafe26a4d821a0b885cf00b)
1.\" Copyright (c) 1991, 1993
2.\"	The Regents of the University of California.  All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" the American National Standards Committee X3, on Information
6.\" Processing Systems.
7.\"
8.\" Redistribution and use in source and binary forms, with or without
9.\" modification, are permitted provided that the following conditions
10.\" are met:
11.\" 1. Redistributions of source code must retain the above copyright
12.\"    notice, this list of conditions and the following disclaimer.
13.\" 2. Redistributions in binary form must reproduce the above copyright
14.\"    notice, this list of conditions and the following disclaimer in the
15.\"    documentation and/or other materials provided with the distribution.
16.\" 4. Neither the name of the University nor the names of its contributors
17.\"    may be used to endorse or promote products derived from this software
18.\"    without specific prior written permission.
19.\"
20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30.\" SUCH DAMAGE.
31.\"
32.\"     @(#)ldexp.3	8.2 (Berkeley) 4/19/94
33.\" $FreeBSD$
34.\"
35.Dd March 4, 2005
36.Dt LDEXP 3
37.Os
38.Sh NAME
39.Nm ldexp ,
40.Nm ldexpf ,
41.Nm ldexpl
42.Nd multiply floating-point number by integral power of 2
43.Sh LIBRARY
44.Lb libm
45.Sh SYNOPSIS
46.In math.h
47.Ft double
48.Fn ldexp "double x" "int exp"
49.Ft float
50.Fn ldexpf "float x" "int exp"
51.Ft long double
52.Fn ldexpl "long double x" "int exp"
53.Sh DESCRIPTION
54The
55.Fn ldexp ,
56.Fn ldexpf ,
57and
58.Fn ldexpl
59functions multiply a floating-point number by an integral
60power of 2.
61.Sh RETURN VALUES
62These functions return the value of
63.Fa x
64times 2 raised to the power
65.Fa exp .
66.Sh SEE ALSO
67.Xr frexp 3 ,
68.Xr math 3 ,
69.Xr modf 3
70.Sh STANDARDS
71The
72.Fn ldexp ,
73.Fn ldexpf ,
74and
75.Fn ldexpl
76functions conform to
77.St -isoC-99 .
78