dp_fsp.c
1.71 KB
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
/* IEEE754 floating point arithmetic
* double precision: common utilities
*/
/*
* MIPS floating point support
* Copyright (C) 1994-2000 Algorithmics Ltd.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "ieee754sp.h"
#include "ieee754dp.h"
static inline union ieee754dp ieee754dp_nan_fsp(int xs, u64 xm)
{
return builddp(xs, DP_EMAX + 1 + DP_EBIAS,
xm << (DP_FBITS - SP_FBITS));
}
union ieee754dp ieee754dp_fsp(union ieee754sp x)
{
COMPXSP;
EXPLODEXSP;
ieee754_clearcx();
FLUSHXSP;
switch (xc) {
case IEEE754_CLASS_SNAN:
return ieee754dp_nanxcpt(ieee754dp_nan_fsp(xs, xm));
case IEEE754_CLASS_QNAN:
return ieee754dp_nan_fsp(xs, xm);
case IEEE754_CLASS_INF:
return ieee754dp_inf(xs);
case IEEE754_CLASS_ZERO:
return ieee754dp_zero(xs);
case IEEE754_CLASS_DNORM:
/* normalize */
while ((xm >> SP_FBITS) == 0) {
xm <<= 1;
xe--;
}
break;
case IEEE754_CLASS_NORM:
break;
}
/*
* Can't possibly overflow,underflow, or need rounding
*/
/* drop the hidden bit */
xm &= ~SP_HIDDEN_BIT;
return builddp(xs, xe + DP_EBIAS,
(u64) xm << (DP_FBITS - SP_FBITS));
}