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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* IEEE754 floating point arithmetic
2 * single precision
3 */
4/*
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
7 * http://www.algor.co.uk
8 *
9 * ########################################################################
10 *
11 * This program is free software; you can distribute it and/or modify it
12 * under the terms of the GNU General Public License (Version 2) as
13 * published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 * for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
23 *
24 * ########################################################################
25 */
26
27
28#include "ieee754sp.h"
29
30ieee754sp ieee754sp_fint(int x)
31{
Atsushi Nemotoecf52d32006-06-01 01:00:03 +090032 unsigned xm;
33 int xe;
34 int xs;
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36 CLEARCX;
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 if (x == 0)
39 return ieee754sp_zero(0);
40 if (x == 1 || x == -1)
41 return ieee754sp_one(x < 0);
42 if (x == 10 || x == -10)
43 return ieee754sp_ten(x < 0);
44
45 xs = (x < 0);
46 if (xs) {
47 if (x == (1 << 31))
48 xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */
49 else
50 xm = -x;
51 } else {
52 xm = x;
53 }
54 xe = SP_MBITS + 3;
55
56 if (xm >> (SP_MBITS + 1 + 3)) {
57 /* shunt out overflow bits
58 */
59 while (xm >> (SP_MBITS + 1 + 3)) {
60 SPXSRSX1();
61 }
62 } else {
63 /* normalize in grs extended single precision
64 */
65 while ((xm >> (SP_MBITS + 3)) == 0) {
66 xm <<= 1;
67 xe--;
68 }
69 }
70 SPNORMRET1(xs, xe, xm, "fint", x);
71}
72
73
74ieee754sp ieee754sp_funs(unsigned int u)
75{
76 if ((int) u < 0)
77 return ieee754sp_add(ieee754sp_1e31(),
78 ieee754sp_fint(u & ~(1 << 31)));
79 return ieee754sp_fint(u);
80}