xref: /freebsd/lib/libc/gen/frexp.3 (revision dc36d6f9bb1753f3808552f3afd30eda9a7b206a)
158f0484fSRodney W. Grimes.\" Copyright (c) 1991, 1993
258f0484fSRodney W. Grimes.\"	The Regents of the University of California.  All rights reserved.
358f0484fSRodney W. Grimes.\"
458f0484fSRodney W. Grimes.\" This code is derived from software contributed to Berkeley by
558f0484fSRodney W. Grimes.\" the American National Standards Committee X3, on Information
658f0484fSRodney W. Grimes.\" Processing Systems.
758f0484fSRodney W. Grimes.\"
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958f0484fSRodney W. Grimes.\" modification, are permitted provided that the following conditions
1058f0484fSRodney W. Grimes.\" are met:
1158f0484fSRodney W. Grimes.\" 1. Redistributions of source code must retain the above copyright
1258f0484fSRodney W. Grimes.\"    notice, this list of conditions and the following disclaimer.
1358f0484fSRodney W. Grimes.\" 2. Redistributions in binary form must reproduce the above copyright
1458f0484fSRodney W. Grimes.\"    notice, this list of conditions and the following disclaimer in the
1558f0484fSRodney W. Grimes.\"    documentation and/or other materials provided with the distribution.
16*fbbd9655SWarner Losh.\" 3. Neither the name of the University nor the names of its contributors
1758f0484fSRodney W. Grimes.\"    may be used to endorse or promote products derived from this software
1858f0484fSRodney W. Grimes.\"    without specific prior written permission.
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2058f0484fSRodney W. Grimes.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
2158f0484fSRodney W. Grimes.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2258f0484fSRodney W. Grimes.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2358f0484fSRodney W. Grimes.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
2458f0484fSRodney W. Grimes.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2558f0484fSRodney W. Grimes.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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2858f0484fSRodney W. Grimes.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2958f0484fSRodney W. Grimes.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
3058f0484fSRodney W. Grimes.\" SUCH DAMAGE.
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32a8af59b5SDavid Schultz.Dd March 4, 2005
3358f0484fSRodney W. Grimes.Dt FREXP 3
3458f0484fSRodney W. Grimes.Os
3558f0484fSRodney W. Grimes.Sh NAME
36a8af59b5SDavid Schultz.Nm frexp ,
37a8af59b5SDavid Schultz.Nm frexpf ,
38a8af59b5SDavid Schultz.Nm frexpl
3958f0484fSRodney W. Grimes.Nd convert floating-point number to fractional and integral components
4025bb73e0SAlexey Zelkin.Sh LIBRARY
416f1dd8edSDavid Schultz.Lb libm
4258f0484fSRodney W. Grimes.Sh SYNOPSIS
4332eef9aeSRuslan Ermilov.In math.h
4458f0484fSRodney W. Grimes.Ft double
4558f0484fSRodney W. Grimes.Fn frexp "double value" "int *exp"
46a8af59b5SDavid Schultz.Ft float
476f1dd8edSDavid Schultz.Fn frexpf "float value" "int *exp"
48a8af59b5SDavid Schultz.Ft long double
49a8af59b5SDavid Schultz.Fn frexpl "long double value" "int *exp"
5058f0484fSRodney W. Grimes.Sh DESCRIPTION
5158f0484fSRodney W. GrimesThe
52a8af59b5SDavid Schultz.Fn frexp ,
536f1dd8edSDavid Schultz.Fn frexpf
54a8af59b5SDavid Schultzand
55a8af59b5SDavid Schultz.Fn frexpl
566f1dd8edSDavid Schultzfunctions break a floating-point number into a normalized
5758f0484fSRodney W. Grimesfraction and an integral power of 2.
586f1dd8edSDavid SchultzThey store the integer in the
595c564baeSRuslan Ermilov.Vt int
6058f0484fSRodney W. Grimesobject pointed to by
6158f0484fSRodney W. Grimes.Fa exp .
6258f0484fSRodney W. Grimes.Sh RETURN VALUES
636f1dd8edSDavid SchultzThese functions return the value
645c564baeSRuslan Ermilov.Va x ,
6558f0484fSRodney W. Grimessuch that
665c564baeSRuslan Ermilov.Va x
6758f0484fSRodney W. Grimesis a
685c564baeSRuslan Ermilov.Vt double
6958f0484fSRodney W. Grimeswith magnitude in the interval
70e03aa09bSUlrich Spörlein.Eo [ 1/2 , 1 Ec )
7158f0484fSRodney W. Grimesor zero, and
7258f0484fSRodney W. Grimes.Fa value
7358f0484fSRodney W. Grimesequals
745c564baeSRuslan Ermilov.Va x
7558f0484fSRodney W. Grimestimes 2 raised to the power
7658f0484fSRodney W. Grimes.Fa *exp .
7758f0484fSRodney W. GrimesIf
7858f0484fSRodney W. Grimes.Fa value
7958f0484fSRodney W. Grimesis zero, both parts of the result are zero.
8058f0484fSRodney W. Grimes.Sh SEE ALSO
8158f0484fSRodney W. Grimes.Xr ldexp 3 ,
8275141cc9SWolfram Schneider.Xr math 3 ,
8375141cc9SWolfram Schneider.Xr modf 3
8458f0484fSRodney W. Grimes.Sh STANDARDS
8558f0484fSRodney W. GrimesThe
86a8af59b5SDavid Schultz.Fn frexp ,
87a8af59b5SDavid Schultz.Fn frexpf ,
886f1dd8edSDavid Schultzand
89a8af59b5SDavid Schultz.Fn frexpl
906f1dd8edSDavid Schultzfunctions conform to
916f1dd8edSDavid Schultz.St -isoC-99 .
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