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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* IEEE754 floating point arithmetic
2 * double precision: common utilities
3 */
4/*
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * This program is free software; you can distribute it and/or modify it
9 * under the terms of the GNU General Public License (Version 2) as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
Ralf Baechle3f7cac42014-04-26 01:49:14 +020019 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
Linus Torvalds1da177e2005-04-16 15:20:36 -070020 */
21
Ralf Baechleb3a7ad22014-04-22 16:33:07 +020022#include "ieee754sp.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include "ieee754dp.h"
24
Maciej W. Rozyckid19cf862015-04-03 23:25:23 +010025static inline union ieee754dp ieee754dp_nan_fsp(int xs, u64 xm)
26{
27 return builddp(xs, DP_EMAX + 1 + DP_EBIAS,
28 xm << (DP_FBITS - SP_FBITS));
29}
30
Ralf Baechle2209bcb2014-04-16 01:31:11 +020031union ieee754dp ieee754dp_fsp(union ieee754sp x)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032{
33 COMPXSP;
34
35 EXPLODEXSP;
36
Ralf Baechle9e8bad12014-04-19 00:36:32 +020037 ieee754_clearcx();
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39 FLUSHXSP;
40
41 switch (xc) {
42 case IEEE754_CLASS_SNAN:
Maciej W. Rozyckid5afa7e2015-04-03 23:25:34 +010043 return ieee754dp_nanxcpt(ieee754dp_nan_fsp(xs, xm));
Ralf Baechle3f7cac42014-04-26 01:49:14 +020044
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 case IEEE754_CLASS_QNAN:
Maciej W. Rozycki539bfb52015-04-03 23:25:30 +010046 return ieee754dp_nan_fsp(xs, xm);
Maciej W. Rozyckid19cf862015-04-03 23:25:23 +010047
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 case IEEE754_CLASS_INF:
49 return ieee754dp_inf(xs);
Ralf Baechle3f7cac42014-04-26 01:49:14 +020050
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 case IEEE754_CLASS_ZERO:
52 return ieee754dp_zero(xs);
Ralf Baechle3f7cac42014-04-26 01:49:14 +020053
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 case IEEE754_CLASS_DNORM:
55 /* normalize */
Ralf Baechlead8fb5532014-04-22 15:51:55 +020056 while ((xm >> SP_FBITS) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 xm <<= 1;
58 xe--;
59 }
60 break;
Ralf Baechle3f7cac42014-04-26 01:49:14 +020061
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 case IEEE754_CLASS_NORM:
63 break;
64 }
65
Ralf Baechle3f7cac42014-04-26 01:49:14 +020066 /*
67 * Can't possibly overflow,underflow, or need rounding
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 */
69
70 /* drop the hidden bit */
71 xm &= ~SP_HIDDEN_BIT;
72
73 return builddp(xs, xe + DP_EBIAS,
Ralf Baechlead8fb5532014-04-22 15:51:55 +020074 (u64) xm << (DP_FBITS - SP_FBITS));
Linus Torvalds1da177e2005-04-16 15:20:36 -070075}