OpenCores
URL https://opencores.org/ocsvn/or1k/or1k/trunk

Subversion Repositories or1k

[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [arch/] [mips/] [math-emu/] [dp_tint.c] - Blame information for rev 1765

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 1275 phoenix 
/* IEEE754 floating point arithmetic
2 
 * double precision: common utilities
3 
 */
4 
/*
5 
 * MIPS floating point support
6 
 * Copyright (C) 1994-2000 Algorithmics Ltd.  All rights reserved.
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 <linux/kernel.h>
29 
#include "ieee754dp.h"
30 
 
31 
int ieee754dp_tint(ieee754dp x)
32 
{
33 
        COMPXDP;
34 
 
35 
        CLEARCX;
36 
 
37 
        EXPLODEXDP;
38 
        FLUSHXDP;
39 
 
40 
        switch (xc) {
41 
        case IEEE754_CLASS_SNAN:
42 
        case IEEE754_CLASS_QNAN:
43 
        case IEEE754_CLASS_INF:
44 
                SETCX(IEEE754_INVALID_OPERATION);
45 
                return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);
46 
        case IEEE754_CLASS_ZERO:
47 
                return 0;
48 
        case IEEE754_CLASS_DNORM:
49 
        case IEEE754_CLASS_NORM:
50 
                break;
51 
        }
52 
        if (xe > 31) {
53 
                /* Set invalid. We will only use overflow for floating
54 
                   point overflow */
55 
                SETCX(IEEE754_INVALID_OPERATION);
56 
                return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);
57 
        }
58 
        /* oh gawd */
59 
        if (xe > DP_MBITS) {
60 
                xm <<= xe - DP_MBITS;
61 
        } else if (xe < DP_MBITS) {
62 
                u64 residue;
63 
                int round;
64 
                int sticky;
65 
                int odd;
66 
 
67 
                if (xe < -1) {
68 
                        residue = xm;
69 
                        round = 0;
70 
                        sticky = residue != 0;
71 
                        xm = 0;
72 
                }
73 
                else {
74 
                        residue = xm << (64 - DP_MBITS + xe);
75 
                        round = (residue >> 63) != 0;
76 
                        sticky = (residue << 1) != 0;
77 
                        xm >>= DP_MBITS - xe;
78 
                }
79 
                /* Note: At this point upper 32 bits of xm are guaranteed
80 
                   to be zero */
81 
                odd = (xm & 0x1) != 0x0;
82 
                switch (ieee754_csr.rm) {
83 
                case IEEE754_RN:
84 
                        if (round && (sticky || odd))
85 
                                xm++;
86 
                        break;
87 
                case IEEE754_RZ:
88 
                        break;
89 
                case IEEE754_RU:        /* toward +Infinity */
90 
                        if ((round || sticky) && !xs)
91 
                                xm++;
92 
                        break;
93 
                case IEEE754_RD:        /* toward -Infinity */
94 
                        if ((round || sticky) && xs)
95 
                                xm++;
96 
                        break;
97 
                }
98 
                /* look for valid corner case 0x80000000 */
99 
                if ((xm >> 31) != 0 && (xs == 0 || xm != 0x80000000)) {
100 
                        /* This can happen after rounding */
101 
                        SETCX(IEEE754_INVALID_OPERATION);
102 
                        return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);
103 
                }
104 
                if (round || sticky)
105 
                        SETCX(IEEE754_INEXACT);
106 
        }
107 
        if (xs)
108 
                return -xm;
109 
        else
110 
                return xm;
111 
}
112 
 
113 
 
114 
unsigned int ieee754dp_tuns(ieee754dp x)
115 
{
116 
        ieee754dp hb = ieee754dp_1e31();
117 
 
118 
        /* what if x < 0 ?? */
119 
        if (ieee754dp_lt(x, hb))
120 
                return (unsigned) ieee754dp_tint(x);
121 
 
122 
        return (unsigned) ieee754dp_tint(ieee754dp_sub(x, hb)) |
123 
            ((unsigned) 1 << 31);
124 
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.