MIPS: math-emu: Checkpatch cleanup
[sfrench/cifs-2.6.git] / arch / mips / math-emu / dp_tlong.c
1 /* IEEE754 floating point arithmetic
2  * double precision: common utilities
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 "ieee754dp.h"
29
30 s64 ieee754dp_tlong(ieee754dp x)
31 {
32         COMPXDP;
33
34         CLEARCX;
35
36         EXPLODEXDP;
37         FLUSHXDP;
38
39         switch (xc) {
40         case IEEE754_CLASS_SNAN:
41         case IEEE754_CLASS_QNAN:
42         case IEEE754_CLASS_INF:
43                 SETCX(IEEE754_INVALID_OPERATION);
44                 return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
45         case IEEE754_CLASS_ZERO:
46                 return 0;
47         case IEEE754_CLASS_DNORM:
48         case IEEE754_CLASS_NORM:
49                 break;
50         }
51         if (xe >= 63) {
52                 /* look for valid corner case */
53                 if (xe == 63 && xs && xm == DP_HIDDEN_BIT)
54                         return -0x8000000000000000LL;
55                 /* Set invalid. We will only use overflow for floating
56                    point overflow */
57                 SETCX(IEEE754_INVALID_OPERATION);
58                 return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
59         }
60         /* oh gawd */
61         if (xe > DP_MBITS) {
62                 xm <<= xe - DP_MBITS;
63         } else if (xe < DP_MBITS) {
64                 u64 residue;
65                 int round;
66                 int sticky;
67                 int odd;
68
69                 if (xe < -1) {
70                         residue = xm;
71                         round = 0;
72                         sticky = residue != 0;
73                         xm = 0;
74                 } else {
75                         /* Shifting a u64 64 times does not work,
76                         * so we do it in two steps. Be aware that xe
77                         * may be -1 */
78                         residue = xm << (xe + 1);
79                         residue <<= 63 - DP_MBITS;
80                         round = (residue >> 63) != 0;
81                         sticky = (residue << 1) != 0;
82                         xm >>= DP_MBITS - xe;
83                 }
84                 odd = (xm & 0x1) != 0x0;
85                 switch (ieee754_csr.rm) {
86                 case IEEE754_RN:
87                         if (round && (sticky || odd))
88                                 xm++;
89                         break;
90                 case IEEE754_RZ:
91                         break;
92                 case IEEE754_RU:        /* toward +Infinity */
93                         if ((round || sticky) && !xs)
94                                 xm++;
95                         break;
96                 case IEEE754_RD:        /* toward -Infinity */
97                         if ((round || sticky) && xs)
98                                 xm++;
99                         break;
100                 }
101                 if ((xm >> 63) != 0) {
102                         /* This can happen after rounding */
103                         SETCX(IEEE754_INVALID_OPERATION);
104                         return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
105                 }
106                 if (round || sticky)
107                         SETCX(IEEE754_INEXACT);
108         }
109         if (xs)
110                 return -xm;
111         else
112                 return xm;
113 }
114
115
116 u64 ieee754dp_tulong(ieee754dp x)
117 {
118         ieee754dp hb = ieee754dp_1e63();
119
120         /* what if x < 0 ?? */
121         if (ieee754dp_lt(x, hb))
122                 return (u64) ieee754dp_tlong(x);
123
124         return (u64) ieee754dp_tlong(ieee754dp_sub(x, hb)) |
125             (1ULL << 63);
126 }