9428e108c9
These trivial implementations are about 25 times slower than
rint{,f}() on x86 due to the FP environment save/restore.
They should eventually be redone in terms of fegetround() and
bit fiddling.
102 lines
2.9 KiB
Groff
102 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: @(#)rint.3 5.1 (Berkeley) 5/2/91
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.\" $FreeBSD$
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.\"
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.Dd July 5, 2004
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.Dt RINT 3
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.Os
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.Sh NAME
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.Nm nearbyint ,
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.Nm nearbyintf ,
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.Nm rint ,
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.Nm rintf
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.Nd round to integral value in floating-point format
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.Sh LIBRARY
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.Lb libm
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.Sh SYNOPSIS
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.In math.h
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.Ft double
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.Fn nearbyint "double x"
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.Ft float
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.Fn nearbyintf "float x"
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.Ft double
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.Fn rint "double x"
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.Ft float
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.Fn rintf "float x"
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.Sh DESCRIPTION
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The
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.Fn rint
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and the
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.Fn rintf
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functions return the integral value nearest to
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.Fa x
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according to the prevailing rounding mode.
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These functions raise an inexact exception when the original argument
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is not an exact integer.
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.Pp
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The
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.Fn nearbyint
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and
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.Fn nearbyintf
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functions perform the same operation, except that they do not raise
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an inexact exception.
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.Sh SEE ALSO
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.Xr abs 3 ,
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.Xr ceil 3 ,
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.Xr fabs 3 ,
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.Xr fenv 3 ,
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.Xr floor 3 ,
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.Xr ieee 3 ,
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.Xr math 3 ,
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.Xr round 3
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.Sh STANDARDS
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The
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.Fn nearbyint ,
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.Fn nearbyintf ,
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.Fn rint ,
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and
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.Fn rintf
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functions conform to
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.St -isoC-99 .
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.Sh HISTORY
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A
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.Fn rint
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function appeared in
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.At v6 .
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The
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.Fn nearbyint
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and
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.Fn nearbyintf
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functions appeared in
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.Fx 5.3 .
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