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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
Ralf Baechle2209bcb2014-04-16 01:31:11 +020025union ieee754dp ieee754dp_fsp(union ieee754sp x)
Linus Torvalds1da177e2005-04-16 15:20:36 -070026{
27 COMPXSP;
28
29 EXPLODEXSP;
30
Ralf Baechle9e8bad12014-04-19 00:36:32 +020031 ieee754_clearcx();
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33 FLUSHXSP;
34
35 switch (xc) {
36 case IEEE754_CLASS_SNAN:
Ralf Baechle9e8bad12014-04-19 00:36:32 +020037 ieee754_setcx(IEEE754_INVALID_OPERATION);
Ralf Baechle90efba32014-04-25 03:19:57 +020038 return ieee754dp_nanxcpt(ieee754dp_indef());
Ralf Baechle3f7cac42014-04-26 01:49:14 +020039
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 case IEEE754_CLASS_QNAN:
41 return ieee754dp_nanxcpt(builddp(xs,
42 DP_EMAX + 1 + DP_EBIAS,
43 ((u64) xm
Ralf Baechlead8fb5532014-04-22 15:51:55 +020044 << (DP_FBITS -
Ralf Baechle90efba32014-04-25 03:19:57 +020045 SP_FBITS))));
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 case IEEE754_CLASS_INF:
47 return ieee754dp_inf(xs);
Ralf Baechle3f7cac42014-04-26 01:49:14 +020048
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 case IEEE754_CLASS_ZERO:
50 return ieee754dp_zero(xs);
Ralf Baechle3f7cac42014-04-26 01:49:14 +020051
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 case IEEE754_CLASS_DNORM:
53 /* normalize */
Ralf Baechlead8fb5532014-04-22 15:51:55 +020054 while ((xm >> SP_FBITS) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 xm <<= 1;
56 xe--;
57 }
58 break;
Ralf Baechle3f7cac42014-04-26 01:49:14 +020059
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 case IEEE754_CLASS_NORM:
61 break;
62 }
63
Ralf Baechle3f7cac42014-04-26 01:49:14 +020064 /*
65 * Can't possibly overflow,underflow, or need rounding
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 */
67
68 /* drop the hidden bit */
69 xm &= ~SP_HIDDEN_BIT;
70
71 return builddp(xs, xe + DP_EBIAS,
Ralf Baechlead8fb5532014-04-22 15:51:55 +020072 (u64) xm << (DP_FBITS - SP_FBITS));
Linus Torvalds1da177e2005-04-16 15:20:36 -070073}