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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 | ||
f148af25 | 54 | int8 SetRoundingMode(const unsigned int opcode) |
1da177e4 LT |
55 | { |
56 | switch (opcode & MASK_ROUNDING_MODE) { | |
57 | default: | |
58 | case ROUND_TO_NEAREST: | |
f148af25 | 59 | return float_round_nearest_even; |
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60 | |
61 | case ROUND_TO_PLUS_INFINITY: | |
f148af25 | 62 | return float_round_up; |
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63 | |
64 | case ROUND_TO_MINUS_INFINITY: | |
f148af25 | 65 | return float_round_down; |
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66 | |
67 | case ROUND_TO_ZERO: | |
f148af25 | 68 | return float_round_to_zero; |
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69 | } |
70 | } | |
71 | ||
f148af25 | 72 | int8 SetRoundingPrecision(const unsigned int opcode) |
1da177e4 LT |
73 | { |
74 | #ifdef CONFIG_FPE_NWFPE_XP | |
75 | switch (opcode & MASK_ROUNDING_PRECISION) { | |
76 | case ROUND_SINGLE: | |
f148af25 | 77 | return 32; |
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78 | |
79 | case ROUND_DOUBLE: | |
f148af25 | 80 | return 64; |
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81 | |
82 | case ROUND_EXTENDED: | |
f148af25 | 83 | return 80; |
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84 | |
85 | default: | |
f148af25 | 86 | return 80; |
1da177e4 LT |
87 | } |
88 | #endif | |
f148af25 | 89 | return 80; |
1da177e4 LT |
90 | } |
91 | ||
92 | void nwfpe_init_fpa(union fp_state *fp) | |
93 | { | |
94 | FPA11 *fpa11 = (FPA11 *)fp; | |
95 | #ifdef NWFPE_DEBUG | |
96 | printk("NWFPE: setting up state.\n"); | |
97 | #endif | |
98 | memset(fpa11, 0, sizeof(FPA11)); | |
99 | resetFPA11(); | |
1da177e4 LT |
100 | fpa11->initflag = 1; |
101 | } | |
102 | ||
103 | /* Emulate the instruction in the opcode. */ | |
104 | unsigned int EmulateAll(unsigned int opcode) | |
105 | { | |
106 | unsigned int code; | |
107 | ||
108 | #ifdef NWFPE_DEBUG | |
109 | printk("NWFPE: emulating opcode %08x\n", opcode); | |
110 | #endif | |
111 | code = opcode & 0x00000f00; | |
112 | if (code == 0x00000100 || code == 0x00000200) { | |
113 | /* For coprocessor 1 or 2 (FPA11) */ | |
114 | code = opcode & 0x0e000000; | |
115 | if (code == 0x0e000000) { | |
116 | if (opcode & 0x00000010) { | |
117 | /* Emulate conversion opcodes. */ | |
118 | /* Emulate register transfer opcodes. */ | |
119 | /* Emulate comparison opcodes. */ | |
120 | return EmulateCPRT(opcode); | |
121 | } else { | |
122 | /* Emulate monadic arithmetic opcodes. */ | |
123 | /* Emulate dyadic arithmetic opcodes. */ | |
124 | return EmulateCPDO(opcode); | |
125 | } | |
126 | } else if (code == 0x0c000000) { | |
127 | /* Emulate load/store opcodes. */ | |
128 | /* Emulate load/store multiple opcodes. */ | |
129 | return EmulateCPDT(opcode); | |
130 | } | |
131 | } | |
132 | ||
133 | /* Invalid instruction detected. Return FALSE. */ | |
134 | return 0; | |
135 | } |