1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
/* $OpenBSD: sfcmp.c,v 1.4 2001/03/29 03:58:19 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);
}
|
