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
|
/* IEEE754 floating point arithmetic
* single precision
*/
/*
* 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.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* ########################################################################
*/
#include "ieee754sp.h"
ieee754sp ieee754sp_fdp(ieee754dp x)
{
COMPXDP;
ieee754sp nan;
EXPLODEXDP;
CLEARCX;
FLUSHXDP;
switch (xc) {
case IEEE754_CLASS_SNAN:
SETCX(IEEE754_INVALID_OPERATION);
return ieee754sp_nanxcpt(ieee754sp_indef(), "fdp");
case IEEE754_CLASS_QNAN:
nan = buildsp(xs, SP_EMAX + 1 + SP_EBIAS, (u32)
(xm >> (DP_MBITS - SP_MBITS)));
if (!ieee754sp_isnan(nan))
nan = ieee754sp_indef();
return ieee754sp_nanxcpt(nan, "fdp", x);
case IEEE754_CLASS_INF:
return ieee754sp_inf(xs);
case IEEE754_CLASS_ZERO:
return ieee754sp_zero(xs);
case IEEE754_CLASS_DNORM:
/* can't possibly be sp representable */
SETCX(IEEE754_UNDERFLOW);
SETCX(IEEE754_INEXACT);
if ((ieee754_csr.rm == IEEE754_RU && !xs) ||
(ieee754_csr.rm == IEEE754_RD && xs))
return ieee754sp_xcpt(ieee754sp_mind(xs), "fdp", x);
return ieee754sp_xcpt(ieee754sp_zero(xs), "fdp", x);
case IEEE754_CLASS_NORM:
break;
}
{
u32 rm;
/* convert from DP_MBITS to SP_MBITS+3 with sticky right shift
*/
rm = (xm >> (DP_MBITS - (SP_MBITS + 3))) |
((xm << (64 - (DP_MBITS - (SP_MBITS + 3)))) != 0);
SPNORMRET1(xs, xe, rm, "fdp", x);
}
}
|
