/*
* 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.
*/
/*
* dbl_cmp: compare two values
*/
int
dbl_fcmp(dbl_floating_point *leftptr, dbl_floating_point *rightptr,
unsigned int cond, unsigned int *status)
{
register unsigned int leftp1, leftp2, rightp1, rightp2;
register int xorresult;
/* Create local copies of the numbers */
Dbl_copyfromptr(leftptr,leftp1,leftp2);
Dbl_copyfromptr(rightptr,rightp1,rightp2);
/*
* Test for NaN
*/
if( (Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
|| (Dbl_exponent(rightp1) == DBL_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( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(leftp1,leftp2)
&& (Exception(cond) || Dbl_isone_signaling(leftp1)))
||
((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(rightp1,rightp2)
&& (Exception(cond) || Dbl_isone_signaling(rightp1))) )
{
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( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(leftp1,leftp2))
||
((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(rightp1,rightp2)) )
{
/* 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 */
Dbl_xortointp1(leftp1,rightp1,xorresult);
if( xorresult < 0 )
{
/* left negative => less, left positive => greater.
* equal is possible if both operands are zeros. */
if( Dbl_iszero_exponentmantissa(leftp1,leftp2)
&& Dbl_iszero_exponentmantissa(rightp1,rightp2) )
{
Set_status_cbit(Equal(cond));
}
else if( Dbl_isone_sign(leftp1) )
{
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(Dbl_isequal(leftp1,leftp2,rightp1,rightp2))
{
Set_status_cbit(Equal(cond));
}
else if( Dbl_iszero_sign(leftp1) )
{
/* Positive compare */
if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
{
Set_status_cbit(Lessthan(cond));
}
else if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
{
Set_status_cbit(Greaterthan(cond));
}
else
{
/* Equal first parts. Now we must use unsigned compares to
* resolve the two possibilities. */
if( Dbl_allp2(leftp2) < Dbl_allp2(rightp2) )
{
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( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
{
Set_status_cbit(Lessthan(cond));
}
else if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
{
Set_status_cbit(Greaterthan(cond));
}
else
{
/* Equal first parts. Now we must use unsigned compares to
* resolve the two possibilities. */
if( Dbl_allp2(leftp2) > Dbl_allp2(rightp2) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
}
return(NOEXCEPTION);
}
