minix/lib/libm/man/ldexp.3
Lionel Sambuc 84d9c625bf Synchronize on NetBSD-CVS (2013/12/1 12:00:00 UTC)
- Fix for possible unset uid/gid in toproto
 - Fix for default mtree style
 - Update libelf
 - Importing libexecinfo
 - Resynchronize GCC, mpc, gmp, mpfr
 - build.sh: Replace params with show-params.
     This has been done as the make target has been renamed in the same
     way, while a new target named params has been added. This new
     target generates a file containing all the parameters, instead of
     printing it on the console.
 - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
     get getservbyport() out of the inner loop

Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
2014-07-28 17:05:06 +02:00

102 lines
3 KiB
Groff

.\" $NetBSD: ldexp.3,v 1.4 2011/09/18 05:33:13 jruoho Exp $
.\"
.\" Copyright (c) 1991, 1993
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.\" This code is derived from software contributed to Berkeley by
.\" the American National Standards Committee X3, on Information
.\" Processing Systems.
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.\" @(#)ldexp.3 8.2 (Berkeley) 4/19/94
.\"
.Dd September 18, 2011
.Dt LDEXP 3
.Os
.Sh NAME
.Nm ldexp ,
.Nm ldexpf
.Nd multiply floating-point number by integral power of 2
.Sh LIBRARY
.Lb libm
.Sh SYNOPSIS
.In math.h
.Ft double
.Fn ldexp "double x" "int exp"
.Ft float
.Fn ldexpf "float x" "int exp"
.Sh DESCRIPTION
The
.Fn ldexp
family of functions compute
.Bd -ragged -offset indent
.Va x
*
2^\fIexp\fR
.Ed
.Pp
for a real floating-point number
.Fa x .
.Sh RETURN VALUES
The functions return the value of
.Fa x
times 2 raised to the power
.Fa exp .
Otherwise the following may occur:
.Bl -enum -offset indent
.It
If
.Fa x
is \*(Na, a \*(Na is returned.
.It
If
.Fa exp
is zero or
.Fa x
is either \*(Pm 0 or \*(Pm\[if],
.Fa x
is returned.
.It
If the call would cause an overflow, a range error occurs and either
.Dv \*(Pm\*HHUGE_VAL ,
.Dv \*(Pm\*HHUGE_VALF ,
or
.Dv \*(Pm\*HHUGE_VALL
is returned, depending on the sign of
.Fa x
and the type of the return value.
.It
If an underflow would be caused by the correct value,
and the value is not representable, either 0.0 or
an implementation-defined value is returned.
.El
.Sh SEE ALSO
.Xr frexp 3 ,
.Xr math 3 ,
.Xr modf 3
.Sh STANDARDS
The described functions conform to
.St -isoC-99 .