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gerrit-public.fairphone.software / kernel / msm-4.9 / 8021a4a048a85906302bd0236f3d125473be65b1 / . / arch / mips / math-emu / sp_tlong.c
blob: d0ca6e22be29278daf1d52fe7c7c9129d1c0d403 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]1/* IEEE754 floating point arithmetic
2 * single precision
3 */
4/*
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]7 *
8 * ########################################################################
9 *
10 * This program is free software; you can distribute it and/or modify it
11 * under the terms of the GNU General Public License (Version 2) as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 * for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * ########################################################################
24 */
25
26
27#include "ieee754sp.h"
28
29s64 ieee754sp_tlong(ieee754sp x)
30{
31 COMPXDP; /* <-- need 64-bit mantissa tmp */
32
33 CLEARCX;
34
35 EXPLODEXSP;
36 FLUSHXSP;
37
38 switch (xc) {
39 case IEEE754_CLASS_SNAN:
40 case IEEE754_CLASS_QNAN:
41 case IEEE754_CLASS_INF:
42 SETCX(IEEE754_INVALID_OPERATION);
43 return ieee754di_xcpt(ieee754di_indef(), "sp_tlong", x);
44 case IEEE754_CLASS_ZERO:
45 return 0;
46 case IEEE754_CLASS_DNORM:
47 case IEEE754_CLASS_NORM:
48 break;
49 }
50 if (xe >= 63) {
51 /* look for valid corner case */
52 if (xe == 63 && xs && xm == SP_HIDDEN_BIT)
53 return -0x8000000000000000LL;
54 /* Set invalid. We will only use overflow for floating
55 point overflow */
56 SETCX(IEEE754_INVALID_OPERATION);
57 return ieee754di_xcpt(ieee754di_indef(), "sp_tlong", x);
58 }
59 /* oh gawd */
60 if (xe > SP_MBITS) {
61 xm <<= xe - SP_MBITS;
62 } else if (xe < SP_MBITS) {
63 u32 residue;
64 int round;
65 int sticky;
66 int odd;
67
68 if (xe < -1) {
69 residue = xm;
70 round = 0;
71 sticky = residue != 0;
72 xm = 0;
Andrea Gelminiabb86dc2010-05-23 21:52:10 +0200[diff] [blame]73 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]74 residue = xm << (32 - SP_MBITS + xe);
75 round = (residue >> 31) != 0;
76 sticky = (residue << 1) != 0;
77 xm >>= SP_MBITS - xe;
78 }
79 odd = (xm & 0x1) != 0x0;
80 switch (ieee754_csr.rm) {
81 case IEEE754_RN:
82 if (round && (sticky || odd))
83 xm++;
84 break;
85 case IEEE754_RZ:
86 break;
87 case IEEE754_RU: /* toward +Infinity */
88 if ((round || sticky) && !xs)
89 xm++;
90 break;
91 case IEEE754_RD: /* toward -Infinity */
92 if ((round || sticky) && xs)
93 xm++;
94 break;
95 }
96 if ((xm >> 63) != 0) {
97 /* This can happen after rounding */
98 SETCX(IEEE754_INVALID_OPERATION);
99 return ieee754di_xcpt(ieee754di_indef(), "sp_tlong", x);
100 }
101 if (round || sticky)
102 SETCX(IEEE754_INEXACT);
103 }
104 if (xs)
105 return -xm;
106 else
107 return xm;
108}
109
110
111u64 ieee754sp_tulong(ieee754sp x)
112{
113 ieee754sp hb = ieee754sp_1e63();
114
115 /* what if x < 0 ?? */
116 if (ieee754sp_lt(x, hb))
117 return (u64) ieee754sp_tlong(x);
118
119 return (u64) ieee754sp_tlong(ieee754sp_sub(x, hb)) |
120 (1ULL << 63);
121}