Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | NetWinder Floating Point Emulator | |
3 | (c) Rebel.COM, 1998,1999 | |
4 | (c) Philip Blundell, 2001 | |
5 | ||
6 | Direct questions, comments to Scott Bambrough <scottb@netwinder.org> | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | */ | |
22 | ||
23 | #include "fpa11.h" | |
24 | #include "fpopcode.h" | |
25 | ||
26 | #include "fpmodule.h" | |
27 | #include "fpmodule.inl" | |
28 | ||
29 | #include <linux/config.h> | |
30 | #include <linux/compiler.h> | |
31 | #include <linux/string.h> | |
32 | #include <asm/system.h> | |
33 | ||
34 | /* forward declarations */ | |
35 | unsigned int EmulateCPDO(const unsigned int); | |
36 | unsigned int EmulateCPDT(const unsigned int); | |
37 | unsigned int EmulateCPRT(const unsigned int); | |
38 | ||
39 | /* Reset the FPA11 chip. Called to initialize and reset the emulator. */ | |
40 | static void resetFPA11(void) | |
41 | { | |
42 | int i; | |
43 | FPA11 *fpa11 = GET_FPA11(); | |
44 | ||
45 | /* initialize the register type array */ | |
46 | for (i = 0; i <= 7; i++) { | |
47 | fpa11->fType[i] = typeNone; | |
48 | } | |
49 | ||
50 | /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */ | |
51 | fpa11->fpsr = FP_EMULATOR | BIT_AC; | |
52 | } | |
53 | ||
54 | void SetRoundingMode(const unsigned int opcode) | |
55 | { | |
56 | switch (opcode & MASK_ROUNDING_MODE) { | |
57 | default: | |
58 | case ROUND_TO_NEAREST: | |
59 | float_rounding_mode = float_round_nearest_even; | |
60 | break; | |
61 | ||
62 | case ROUND_TO_PLUS_INFINITY: | |
63 | float_rounding_mode = float_round_up; | |
64 | break; | |
65 | ||
66 | case ROUND_TO_MINUS_INFINITY: | |
67 | float_rounding_mode = float_round_down; | |
68 | break; | |
69 | ||
70 | case ROUND_TO_ZERO: | |
71 | float_rounding_mode = float_round_to_zero; | |
72 | break; | |
73 | } | |
74 | } | |
75 | ||
76 | void SetRoundingPrecision(const unsigned int opcode) | |
77 | { | |
78 | #ifdef CONFIG_FPE_NWFPE_XP | |
79 | switch (opcode & MASK_ROUNDING_PRECISION) { | |
80 | case ROUND_SINGLE: | |
81 | floatx80_rounding_precision = 32; | |
82 | break; | |
83 | ||
84 | case ROUND_DOUBLE: | |
85 | floatx80_rounding_precision = 64; | |
86 | break; | |
87 | ||
88 | case ROUND_EXTENDED: | |
89 | floatx80_rounding_precision = 80; | |
90 | break; | |
91 | ||
92 | default: | |
93 | floatx80_rounding_precision = 80; | |
94 | } | |
95 | #endif | |
96 | } | |
97 | ||
98 | void nwfpe_init_fpa(union fp_state *fp) | |
99 | { | |
100 | FPA11 *fpa11 = (FPA11 *)fp; | |
101 | #ifdef NWFPE_DEBUG | |
102 | printk("NWFPE: setting up state.\n"); | |
103 | #endif | |
104 | memset(fpa11, 0, sizeof(FPA11)); | |
105 | resetFPA11(); | |
106 | SetRoundingMode(ROUND_TO_NEAREST); | |
107 | SetRoundingPrecision(ROUND_EXTENDED); | |
108 | fpa11->initflag = 1; | |
109 | } | |
110 | ||
111 | /* Emulate the instruction in the opcode. */ | |
112 | unsigned int EmulateAll(unsigned int opcode) | |
113 | { | |
114 | unsigned int code; | |
115 | ||
116 | #ifdef NWFPE_DEBUG | |
117 | printk("NWFPE: emulating opcode %08x\n", opcode); | |
118 | #endif | |
119 | code = opcode & 0x00000f00; | |
120 | if (code == 0x00000100 || code == 0x00000200) { | |
121 | /* For coprocessor 1 or 2 (FPA11) */ | |
122 | code = opcode & 0x0e000000; | |
123 | if (code == 0x0e000000) { | |
124 | if (opcode & 0x00000010) { | |
125 | /* Emulate conversion opcodes. */ | |
126 | /* Emulate register transfer opcodes. */ | |
127 | /* Emulate comparison opcodes. */ | |
128 | return EmulateCPRT(opcode); | |
129 | } else { | |
130 | /* Emulate monadic arithmetic opcodes. */ | |
131 | /* Emulate dyadic arithmetic opcodes. */ | |
132 | return EmulateCPDO(opcode); | |
133 | } | |
134 | } else if (code == 0x0c000000) { | |
135 | /* Emulate load/store opcodes. */ | |
136 | /* Emulate load/store multiple opcodes. */ | |
137 | return EmulateCPDT(opcode); | |
138 | } | |
139 | } | |
140 | ||
141 | /* Invalid instruction detected. Return FALSE. */ | |
142 | return 0; | |
143 | } |