83 lines
2.9 KiB
Groff
83 lines
2.9 KiB
Groff
.\" $NetBSD: signbit.3,v 1.2 2004/01/15 20:31:40 wiz Exp $
|
|
.\"
|
|
.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Klaus Klein.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the NetBSD
|
|
.\" Foundation, Inc. and its contributors.
|
|
.\" 4. Neither the name of The NetBSD Foundation nor the names of its
|
|
.\" contributors may be used to endorse or promote products derived
|
|
.\" from this software without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
.\" POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.Dd October 29, 2003
|
|
.Dt SIGNBIT 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm signbit
|
|
.Nd test sign
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In math.h
|
|
.Ft int
|
|
.Fn signbit "real-floating x"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn signbit
|
|
macro determines whether the sign of its argument value
|
|
.Fa x
|
|
is negative.
|
|
An argument represented in a format wider than its semantic type is
|
|
converted to its semantic type first.
|
|
The determination is then based on the type of the argument.
|
|
.Ss IEEE754
|
|
The sign is determined for all values, including infinities, zeroes,
|
|
and NaNs
|
|
.Ss VAX
|
|
The sign is determined for finites, true zeros, and dirty zeroes;
|
|
for ROPs the sign is reported negative.
|
|
.Sh RETURN VALUES
|
|
The
|
|
.Fn signbit
|
|
macro returns a non-zero value if the sign of its value
|
|
.Fa x
|
|
is negative.
|
|
Otherwise 0 is returned.
|
|
.Sh ERRORS
|
|
No errors are defined.
|
|
.Sh SEE ALSO
|
|
.Xr fpclassify 3 ,
|
|
.Xr isfinite 3 ,
|
|
.Xr isnormal 3 ,
|
|
.Xr math 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn signbit
|
|
macro conforms to
|
|
.St -isoC-99 .
|