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1 | /* This file is part of the program psim. |
2 | ||
3 | Copyright (C) 1994-1995, Andrew Cagney <cagney@highland.com.au> | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
3fd725ef | 7 | the Free Software Foundation; either version 3 of the License, or |
c906108c SS |
8 | (at your option) any later version. |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
51b318de | 16 | along with this program; if not, see <http://www.gnu.org/licenses/>. |
c906108c SS |
17 | |
18 | */ | |
19 | ||
20 | ||
21 | /* Creates the files semantics.[hc]. | |
22 | ||
23 | The generated file semantics contains functions that implement the | |
24 | operations required to model a single target processor instruction. | |
25 | ||
26 | Several different variations on the semantics file can be created: | |
27 | ||
28 | o uncached | |
29 | ||
30 | No instruction cache exists. The semantic function | |
31 | needs to generate any required values locally. | |
32 | ||
33 | o cached - separate cracker and semantic | |
34 | ||
35 | Two independant functions are created. Firstly the | |
36 | function that cracks an instruction entering it into a | |
37 | cache and secondly the semantic function propper that | |
38 | uses the cache. | |
39 | ||
40 | o cached - semantic + cracking semantic | |
41 | ||
42 | The function that cracks the instruction and enters | |
43 | all values into the cache also contains a copy of the | |
44 | semantic code (avoiding the need to call both the | |
45 | cracker and the semantic function when there is a | |
46 | cache miss). | |
47 | ||
48 | For each of these general forms, several refinements can occure: | |
49 | ||
50 | o do/don't duplicate/expand semantic functions | |
51 | ||
52 | As a consequence of decoding an instruction, the | |
53 | decoder, as part of its table may have effectivly made | |
54 | certain of the variable fields in an instruction | |
55 | constant. Separate functions for each of the | |
56 | alternative values for what would have been treated as | |
57 | a variable part can be created. | |
58 | ||
59 | o use cache struct directly. | |
60 | ||
61 | When a cracking cache is present, the semantic | |
62 | functions can be generated to either hold intermediate | |
63 | cache values in local variables or always refer to the | |
64 | contents of the cache directly. */ | |
65 | ||
66 | ||
67 | ||
68 | extern insn_handler print_semantic_declaration; | |
69 | extern insn_handler print_semantic_definition; | |
70 | ||
71 | extern void print_idecode_illegal | |
72 | (lf *file, | |
73 | const char *result); | |
74 | ||
75 | extern void print_semantic_body | |
76 | (lf *file, | |
77 | insn *instruction, | |
78 | insn_bits *expanded_bits, | |
79 | opcode_field *opcodes); | |
80 |