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 7 the Free Software Foundation; either version 2 of the License, or 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 16 along with this program; if not, write to the Free Software 17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 18 19 */ 20 21 22 /* Creates the files semantics.[hc]. 23 24 The generated file semantics contains functions that implement the 25 operations required to model a single target processor instruction. 26 27 Several different variations on the semantics file can be created: 28 29 o uncached 30 31 No instruction cache exists. The semantic function 32 needs to generate any required values locally. 33 34 o cached - separate cracker and semantic 35 36 Two independant functions are created. Firstly the 37 function that cracks an instruction entering it into a 38 cache and secondly the semantic function propper that 39 uses the cache. 40 41 o cached - semantic + cracking semantic 42 43 The function that cracks the instruction and enters 44 all values into the cache also contains a copy of the 45 semantic code (avoiding the need to call both the 46 cracker and the semantic function when there is a 47 cache miss). 48 49 For each of these general forms, several refinements can occure: 50 51 o do/don't duplicate/expand semantic functions 52 53 As a consequence of decoding an instruction, the 54 decoder, as part of its table may have effectivly made 55 certain of the variable fields in an instruction 56 constant. Separate functions for each of the 57 alternative values for what would have been treated as 58 a variable part can be created. 59 60 o use cache struct directly. 61 62 When a cracking cache is present, the semantic 63 functions can be generated to either hold intermediate 64 cache values in local variables or always refer to the 65 contents of the cache directly. */ 66 67 68 69 extern insn_handler print_semantic_declaration; 70 extern insn_handler print_semantic_definition; 71 72 extern void print_idecode_illegal 73 (lf *file, 74 const char *result); 75 76 extern void print_semantic_body 77 (lf *file, 78 insn *instruction, 79 insn_bits *expanded_bits, 80 opcode_field *opcodes); 81 82