103 lines
2.9 KiB
Groff
103 lines
2.9 KiB
Groff
.\" Copyright (c) 2003 David Schultz <das@FreeBSD.org>
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd February 12, 2003
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.Dt ISGREATER 3
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.Os
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.Sh NAME
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.Nm isgreater , isgreaterequal , isless , islessequal ,
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.Nm islessgreater , isunordered
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.Nd "compare two floating-point numbers"
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In math.h
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.Ft int
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.Fn isgreater "real-floating x" "real-floating y"
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.Ft int
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.Fn isgreaterequal "real-floating x" "real-floating y"
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.Ft int
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.Fn isless "real-floating x" "real-floating y"
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.Ft int
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.Fn islessequal "real-floating x" "real-floating y"
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.Ft int
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.Fn islessgreater "real-floating x" "real-floating y"
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.Ft int
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.Fn isunordered "real-floating x" "real-floating y"
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.Sh DESCRIPTION
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Each of the macros
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.Fn isgreater ,
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.Fn isgreaterequal ,
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.Fn isless ,
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.Fn islessequal ,
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and
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.Fn islessgreater
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take arguments
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.Fa x
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and
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.Fa y
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and return a non-zero value if and only if its nominal
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relation on
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.Fa x
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and
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.Fa y
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is true.
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These macros always return zero if either
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argument is not a number (NaN), but unlike the corresponding C
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operators, they never raise a floating point exception.
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.Pp
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The
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.Fn isunordered
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macro takes arguments
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.Fa x
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and
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.Fa y
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and returns non-zero if and only if neither
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.Fa x
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nor
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.Fa y
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are NaNs.
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For any pair of floating-point values, one
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of the relationships (less, greater, equal, unordered) holds.
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.Sh SEE ALSO
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.Xr fpclassify 3 ,
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.Xr math 3 ,
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.Xr signbit 3
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.Sh STANDARDS
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The
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.Fn isgreater ,
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.Fn isgreaterequal ,
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.Fn isless ,
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.Fn islessequal ,
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.Fn islessgreater ,
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and
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.Fn isunordered
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macros conform to
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.St -isoC-99 .
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.Sh HISTORY
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The relational macros described above first appeared in
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.Fx 5.1 .
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