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[/] [openrisc/] [trunk/] [gnu-old/] [gdb-6.8/] [sim/] [ppc/] [gen-semantics.h] - Rev 856
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/* This file is part of the program psim. Copyright (C) 1994-1995, Andrew Cagney <cagney@highland.com.au> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Creates the files semantics.[hc]. The generated file semantics contains functions that implement the operations required to model a single target processor instruction. Several different variations on the semantics file can be created: o uncached No instruction cache exists. The semantic function needs to generate any required values locally. o cached - separate cracker and semantic Two independant functions are created. Firstly the function that cracks an instruction entering it into a cache and secondly the semantic function propper that uses the cache. o cached - semantic + cracking semantic The function that cracks the instruction and enters all values into the cache also contains a copy of the semantic code (avoiding the need to call both the cracker and the semantic function when there is a cache miss). For each of these general forms, several refinements can occure: o do/don't duplicate/expand semantic functions As a consequence of decoding an instruction, the decoder, as part of its table may have effectivly made certain of the variable fields in an instruction constant. Separate functions for each of the alternative values for what would have been treated as a variable part can be created. o use cache struct directly. When a cracking cache is present, the semantic functions can be generated to either hold intermediate cache values in local variables or always refer to the contents of the cache directly. */ extern insn_handler print_semantic_declaration; extern insn_handler print_semantic_definition; extern void print_idecode_illegal (lf *file, const char *result); extern void print_semantic_body (lf *file, insn *instruction, insn_bits *expanded_bits, opcode_field *opcodes);
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