98 lines
2.9 KiB
Groff
98 lines
2.9 KiB
Groff
.\" Copyright (c) 1985, 1991 Regents of the University of California.
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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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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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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.\" from: @(#)ieee.3 6.4 (Berkeley) 5/6/91
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.\" $NetBSD: ieee_test.3,v 1.5 1999/07/02 15:37:35 simonb Exp $
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.\"
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.Dd March 10, 1994
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.Dt IEEE_TEST 3
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.Os
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.Sh NAME
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.Nm logb ,
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.Nm scalb ,
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.Nm significand
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.Nd IEEE test functions
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.Sh LIBRARY
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.Lb libm
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.Sh SYNOPSIS
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.Fd #include <math.h>
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.Ft double
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.Fn logb "double x"
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.Ft float
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.Fn logbf "float x"
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.Ft double
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.Fn scalb "double x" "double n"
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.Ft float
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.Fn scalbf "float x" "float n"
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.Ft double
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.Fn significand "double x"
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.Ft float
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.Fn significand "float x"
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.Sh DESCRIPTION
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These functions allow users to test conformance to
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.St -ieee754 .
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Their use is not otherwise recommended.
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.Pp
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.Fn logb x
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returns
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.Fa x Ns 's exponent
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.Fa n ,
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a signed integer converted to double\-precision floating\-point.
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.Fn logb \*(Pm\*(If
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= +\*(If;
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.Fn logb 0
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= -\*(If with a division by zero exception.
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.Pp
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.Fn scalbn x n
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returns
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.Fa x Ns \(**(2** Ns Fa n )
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computed by exponent manipulation.
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.Pp
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.Fn significand x
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returns
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.Fa sig ,
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where
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.Fa x
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:=
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.Fa sig No \(** 2** Ns Fa n
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with 1 \(<=
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.Fa sig
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< 2.
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.Fn significand x
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is not defined when
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.Fa x
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is 0, \*(Pm\*(If, or \*(Na.
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.Sh SEE ALSO
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.Xr ieee 3 ,
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.Xr math 3
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.Sh STANDARDS
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.St -ieee754
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