Subversion Repositories openrisc_2011-10-31

/*  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);