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 | ||
1da177e4 LT |
29 | #include <linux/compiler.h> |
30 | #include <linux/string.h> | |
1da177e4 | 31 | |
1da177e4 LT |
32 | /* Reset the FPA11 chip. Called to initialize and reset the emulator. */ |
33 | static void resetFPA11(void) | |
34 | { | |
35 | int i; | |
36 | FPA11 *fpa11 = GET_FPA11(); | |
37 | ||
38 | /* initialize the register type array */ | |
39 | for (i = 0; i <= 7; i++) { | |
40 | fpa11->fType[i] = typeNone; | |
41 | } | |
42 | ||
43 | /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */ | |
44 | fpa11->fpsr = FP_EMULATOR | BIT_AC; | |
45 | } | |
46 | ||
f148af25 | 47 | int8 SetRoundingMode(const unsigned int opcode) |
1da177e4 LT |
48 | { |
49 | switch (opcode & MASK_ROUNDING_MODE) { | |
50 | default: | |
51 | case ROUND_TO_NEAREST: | |
f148af25 | 52 | return float_round_nearest_even; |
1da177e4 LT |
53 | |
54 | case ROUND_TO_PLUS_INFINITY: | |
f148af25 | 55 | return float_round_up; |
1da177e4 LT |
56 | |
57 | case ROUND_TO_MINUS_INFINITY: | |
f148af25 | 58 | return float_round_down; |
1da177e4 LT |
59 | |
60 | case ROUND_TO_ZERO: | |
f148af25 | 61 | return float_round_to_zero; |
1da177e4 LT |
62 | } |
63 | } | |
64 | ||
f148af25 | 65 | int8 SetRoundingPrecision(const unsigned int opcode) |
1da177e4 LT |
66 | { |
67 | #ifdef CONFIG_FPE_NWFPE_XP | |
68 | switch (opcode & MASK_ROUNDING_PRECISION) { | |
69 | case ROUND_SINGLE: | |
f148af25 | 70 | return 32; |
1da177e4 LT |
71 | |
72 | case ROUND_DOUBLE: | |
f148af25 | 73 | return 64; |
1da177e4 LT |
74 | |
75 | case ROUND_EXTENDED: | |
f148af25 | 76 | return 80; |
1da177e4 LT |
77 | |
78 | default: | |
f148af25 | 79 | return 80; |
1da177e4 LT |
80 | } |
81 | #endif | |
f148af25 | 82 | return 80; |
1da177e4 LT |
83 | } |
84 | ||
85 | void nwfpe_init_fpa(union fp_state *fp) | |
86 | { | |
87 | FPA11 *fpa11 = (FPA11 *)fp; | |
88 | #ifdef NWFPE_DEBUG | |
89 | printk("NWFPE: setting up state.\n"); | |
90 | #endif | |
91 | memset(fpa11, 0, sizeof(FPA11)); | |
92 | resetFPA11(); | |
1da177e4 LT |
93 | fpa11->initflag = 1; |
94 | } | |
95 | ||
96 | /* Emulate the instruction in the opcode. */ | |
97 | unsigned int EmulateAll(unsigned int opcode) | |
98 | { | |
99 | unsigned int code; | |
100 | ||
101 | #ifdef NWFPE_DEBUG | |
102 | printk("NWFPE: emulating opcode %08x\n", opcode); | |
103 | #endif | |
104 | code = opcode & 0x00000f00; | |
105 | if (code == 0x00000100 || code == 0x00000200) { | |
106 | /* For coprocessor 1 or 2 (FPA11) */ | |
107 | code = opcode & 0x0e000000; | |
108 | if (code == 0x0e000000) { | |
109 | if (opcode & 0x00000010) { | |
110 | /* Emulate conversion opcodes. */ | |
111 | /* Emulate register transfer opcodes. */ | |
112 | /* Emulate comparison opcodes. */ | |
113 | return EmulateCPRT(opcode); | |
114 | } else { | |
115 | /* Emulate monadic arithmetic opcodes. */ | |
116 | /* Emulate dyadic arithmetic opcodes. */ | |
117 | return EmulateCPDO(opcode); | |
118 | } | |
119 | } else if (code == 0x0c000000) { | |
120 | /* Emulate load/store opcodes. */ | |
121 | /* Emulate load/store multiple opcodes. */ | |
122 | return EmulateCPDT(opcode); | |
123 | } | |
124 | } | |
125 | ||
126 | /* Invalid instruction detected. Return FALSE. */ | |
127 | return 0; | |
128 | } |