1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/*
NetWinder Floating Point Emulator
(c) Rebel.COM, 1998,1999
(c) Philip Blundell, 2001
Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "fpa11.h"
#include "fpopcode.h"
#include "fpmodule.h"
#include "fpmodule.inl"
#include <linux/config.h>
#include <linux/compiler.h>
#include <linux/string.h>
#include <asm/system.h>
/* forward declarations */
unsigned int EmulateCPDO(const unsigned int);
unsigned int EmulateCPDT(const unsigned int);
unsigned int EmulateCPRT(const unsigned int);
/* Reset the FPA11 chip. Called to initialize and reset the emulator. */
static void resetFPA11(void)
{
int i;
FPA11 *fpa11 = GET_FPA11();
/* initialize the register type array */
for (i = 0; i <= 7; i++) {
fpa11->fType[i] = typeNone;
}
/* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
fpa11->fpsr = FP_EMULATOR | BIT_AC;
}
int8 SetRoundingMode(const unsigned int opcode)
{
switch (opcode & MASK_ROUNDING_MODE) {
default:
case ROUND_TO_NEAREST:
return float_round_nearest_even;
case ROUND_TO_PLUS_INFINITY:
return float_round_up;
case ROUND_TO_MINUS_INFINITY:
return float_round_down;
case ROUND_TO_ZERO:
return float_round_to_zero;
}
}
int8 SetRoundingPrecision(const unsigned int opcode)
{
#ifdef CONFIG_FPE_NWFPE_XP
switch (opcode & MASK_ROUNDING_PRECISION) {
case ROUND_SINGLE:
return 32;
case ROUND_DOUBLE:
return 64;
case ROUND_EXTENDED:
return 80;
default:
return 80;
}
#endif
return 80;
}
void nwfpe_init_fpa(union fp_state *fp)
{
FPA11 *fpa11 = (FPA11 *)fp;
#ifdef NWFPE_DEBUG
printk("NWFPE: setting up state.\n");
#endif
memset(fpa11, 0, sizeof(FPA11));
resetFPA11();
fpa11->initflag = 1;
}
/* Emulate the instruction in the opcode. */
unsigned int EmulateAll(unsigned int opcode)
{
unsigned int code;
#ifdef NWFPE_DEBUG
printk("NWFPE: emulating opcode %08x\n", opcode);
#endif
code = opcode & 0x00000f00;
if (code == 0x00000100 || code == 0x00000200) {
/* For coprocessor 1 or 2 (FPA11) */
code = opcode & 0x0e000000;
if (code == 0x0e000000) {
if (opcode & 0x00000010) {
/* Emulate conversion opcodes. */
/* Emulate register transfer opcodes. */
/* Emulate comparison opcodes. */
return EmulateCPRT(opcode);
} else {
/* Emulate monadic arithmetic opcodes. */
/* Emulate dyadic arithmetic opcodes. */
return EmulateCPDO(opcode);
}
} else if (code == 0x0c000000) {
/* Emulate load/store opcodes. */
/* Emulate load/store multiple opcodes. */
return EmulateCPDT(opcode);
}
}
/* Invalid instruction detected. Return FALSE. */
return 0;
}
|
