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author | Andrew Cagney <cagney@redhat.com> | 1997-02-21 02:49:21 +0000 |
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committer | Andrew Cagney <cagney@redhat.com> | 1997-02-21 02:49:21 +0000 |
commit | a4c97499d90ab83a01d80d4c3df2455a73486e3c (patch) | |
tree | 9a52d25e56a06fec8fa103dbeb4d7477b1f5d23c /sim/igen/gen-semantics.h | |
parent | 317df3b530276f2acbdf8950d1d9b76deb83753c (diff) | |
download | fsf-binutils-gdb-a4c97499d90ab83a01d80d4c3df2455a73486e3c.zip fsf-binutils-gdb-a4c97499d90ab83a01d80d4c3df2455a73486e3c.tar.gz fsf-binutils-gdb-a4c97499d90ab83a01d80d4c3df2455a73486e3c.tar.bz2 |
Instruction decode generator taken from the PowerPC simulator
and being made more generic.
Diffstat (limited to 'sim/igen/gen-semantics.h')
-rw-r--r-- | sim/igen/gen-semantics.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/sim/igen/gen-semantics.h b/sim/igen/gen-semantics.h new file mode 100644 index 0000000..2c25715 --- /dev/null +++ b/sim/igen/gen-semantics.h @@ -0,0 +1,81 @@ +/* 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); + |