103 lines
2.9 KiB
Groff
103 lines
2.9 KiB
Groff
.\" Copyright (c) 2003 David Schultz <das@FreeBSD.ORG>
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" 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.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd February 12, 2003
|
|
.Dt ISGREATER 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm isgreater , isgreaterequal , isless , islessequal ,
|
|
.Nm islessgreater , isunordered
|
|
.Nd "compare two floating-point numbers"
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In math.h
|
|
.Ft int
|
|
.Fn isgreater "real-floating x" "real-floating y"
|
|
.Ft int
|
|
.Fn isgreaterequal "real-floating x" "real-floating y"
|
|
.Ft int
|
|
.Fn isless "real-floating x" "real-floating y"
|
|
.Ft int
|
|
.Fn islessequal "real-floating x" "real-floating y"
|
|
.Ft int
|
|
.Fn islessgreater "real-floating x" "real-floating y"
|
|
.Ft int
|
|
.Fn isunordered "real-floating x" "real-floating y"
|
|
.Sh DESCRIPTION
|
|
Each of the macros
|
|
.Fn isgreater ,
|
|
.Fn isgreaterequal ,
|
|
.Fn isless ,
|
|
.Fn islessequal ,
|
|
and
|
|
.Fn islessgreater
|
|
take arguments
|
|
.Fa x
|
|
and
|
|
.Fa y
|
|
and return a non-zero value if and only if its nominal
|
|
relation on
|
|
.Fa x
|
|
and
|
|
.Fa y
|
|
is true.
|
|
These macros always return zero if either
|
|
argument is not a number (NaN), but unlike the corresponding C
|
|
operators, they never raise a floating point exception.
|
|
.Pp
|
|
The
|
|
.Fn isunordered
|
|
macro takes arguments
|
|
.Fa x
|
|
and
|
|
.Fa y
|
|
and returns non-zero if and only if neither
|
|
.Fa x
|
|
nor
|
|
.Fa y
|
|
are NaNs.
|
|
For any pair of floating-point values, one
|
|
of the relationships (less, greater, equal, unordered) holds.
|
|
.Sh SEE ALSO
|
|
.Xr fpclassify 3 ,
|
|
.Xr math 3 ,
|
|
.Xr signbit 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn isgreater ,
|
|
.Fn isgreaterequal ,
|
|
.Fn isless ,
|
|
.Fn islessequal ,
|
|
.Fn islessgreater ,
|
|
and
|
|
.Fn isunordered
|
|
macros conform to
|
|
.St -isoC-99 .
|
|
.Sh HISTORY
|
|
The relational macros described above first appeared in
|
|
.Fx 5.1 .
|