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/* $OpenBSD: sfcmp.c,v 1.3 1998/07/02 19:05:53 mickey Exp $ */
/*
* Copyright 1996 1995 by Open Software Foundation, Inc.
* All Rights Reserved
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appears in all copies and
* that both the copyright notice and this permission notice appear in
* supporting documentation.
*
* OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
* NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
/*
* pmk1.1
*/
/*
* (c) Copyright 1986 HEWLETT-PACKARD COMPANY
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Hewlett-Packard Company not be
* used in advertising or publicity pertaining to distribution
* of the software without specific, written prior permission.
* Hewlett-Packard Company makes no representations about the
* suitability of this software for any purpose.
*/
#include "../spmath/float.h"
#include "../spmath/sgl_float.h"
/*
* sgl_cmp: compare two values
*/
int
sgl_fcmp(leftptr, rightptr, cond, status)
sgl_floating_point *leftptr, *rightptr;
unsigned int cond; /* The predicate to be tested */
unsigned int *status;
{
register unsigned int left, right;
register int xorresult;
/* Create local copies of the numbers */
left = *leftptr;
right = *rightptr;
/*
* Test for NaN
*/
if( (Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
|| (Sgl_exponent(right) == SGL_INFINITY_EXPONENT) )
{
/* Check if a NaN is involved. Signal an invalid exception when
* comparing a signaling NaN or when comparing quiet NaNs and the
* low bit of the condition is set */
if( ( (Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
&& Sgl_isnotzero_mantissa(left)
&& (Exception(cond) || Sgl_isone_signaling(left)))
||
( (Sgl_exponent(right) == SGL_INFINITY_EXPONENT)
&& Sgl_isnotzero_mantissa(right)
&& (Exception(cond) || Sgl_isone_signaling(right)) ) )
{
if( Is_invalidtrap_enabled() ) {
Set_status_cbit(Unordered(cond));
return(INVALIDEXCEPTION);
}
else Set_invalidflag();
Set_status_cbit(Unordered(cond));
return(NOEXCEPTION);
}
/* All the exceptional conditions are handled, now special case
NaN compares */
else if( ((Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
&& Sgl_isnotzero_mantissa(left))
||
((Sgl_exponent(right) == SGL_INFINITY_EXPONENT)
&& Sgl_isnotzero_mantissa(right)) )
{
/* NaNs always compare unordered. */
Set_status_cbit(Unordered(cond));
return(NOEXCEPTION);
}
/* infinities will drop down to the normal compare mechanisms */
}
/* First compare for unequal signs => less or greater or
* special equal case */
Sgl_xortointp1(left,right,xorresult);
if( xorresult < 0 )
{
/* left negative => less, left positive => greater.
* equal is possible if both operands are zeros. */
if( Sgl_iszero_exponentmantissa(left)
&& Sgl_iszero_exponentmantissa(right) )
{
Set_status_cbit(Equal(cond));
}
else if( Sgl_isone_sign(left) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
/* Signs are the same. Treat negative numbers separately
* from the positives because of the reversed sense. */
else if( Sgl_all(left) == Sgl_all(right) )
{
Set_status_cbit(Equal(cond));
}
else if( Sgl_iszero_sign(left) )
{
/* Positive compare */
if( Sgl_all(left) < Sgl_all(right) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
else
{
/* Negative compare. Signed or unsigned compares
* both work the same. That distinction is only
* important when the sign bits differ. */
if( Sgl_all(left) > Sgl_all(right) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
return(NOEXCEPTION);
}
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