gem5/arch/isa_parser.py
Steve Reinhardt 7cab07268f Do a better job of factoring out CPU model in ISA description.
(Still not perfect though.)

arch/alpha/isa_desc:
    Do a better job of factoring out CPU model.  (Still not perfect though.)
    Pull execute() methods out of class declarations into separate section
    of file, allowing (1) easier replication for different CPU models and
    (2) a path to putting them all in a separate file.  Force all instruction
    execution context into a single model-dependent class (SimpleCPU itself
    for SimpleCPU, DynInst for FullCPU).
arch/isa_parser.py:
    Do a better job of factoring out CPU model.  (Still not perfect though.)
    Pull execute() methods out of class declarations into separate section
    of file, allowing (1) easier replication for different CPU models and
    (2) a path to putting them all in a separate file.
    Also restructure top level to allow parser to run under interactive
    interpreter session for easier debugging.
cpu/exec_context.hh:
    Add a few new methods to clean up isa_desc.
cpu/simple_cpu/simple_cpu.cc:
cpu/static_inst.hh:
    StaticInst::execute no longer takes a CPU and an ExecContext,
    just a unified FooCPUExecContext.
cpu/simple_cpu/simple_cpu.hh:
    Add methods to redirect calls to ExecContext so SimpleCPU
    can act as sole instruction execution context for itself.
    Typedef SimpleCPU to SimpleCPUExecContext.

--HG--
extra : convert_revision : ecc445503bc585585da5663fe61796580e744da6
2004-05-10 16:10:47 -07:00

1466 lines
49 KiB
Python
Executable file

#! /usr/bin/env python
# $Id$
# Copyright (c) 2003 The Regents of The University of Michigan
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met: redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer;
# redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution;
# neither the name of the copyright holders nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import os
import sys
import re
import string
import traceback
# get type names
from types import *
# Prepend the directory where the PLY lex & yacc modules are found
# to the search path. Assumes we're compiling in a subdirectory
# of 'build' in the current tree.
sys.path[0:0] = [os.environ['M5_EXT'] + '/ply']
import lex
import yacc
#####################################################################
#
# Lexer
#
# The PLY lexer module takes two things as input:
# - A list of token names (the string list 'tokens')
# - A regular expression describing a match for each token. The
# regexp for token FOO can be provided in two ways:
# - as a string variable named t_FOO
# - as the doc string for a function named t_FOO. In this case,
# the function is also executed, allowing an action to be
# associated with each token match.
#
#####################################################################
# Reserved words. These are listed separately as they are matched
# using the same regexp as generic IDs, but distinguished in the
# t_ID() function. The PLY documentation suggests this approach.
reserved = (
'BITFIELD', 'DECLARE', 'DECODE', 'DEFAULT', 'DEF', 'FORMAT',
'LET', 'NAMESPACE', 'SIGNED', 'TEMPLATE'
)
# List of tokens. The lex module requires this.
tokens = reserved + (
# identifier
'ID',
# integer literal
'INTLIT',
# string literal
'STRLIT',
# code literal
'CODELIT',
# ( ) [ ] { } < > , ; : :: *
'LPAREN', 'RPAREN',
# not used any more... commented out to suppress PLY warning
# 'LBRACKET', 'RBRACKET',
'LBRACE', 'RBRACE',
'LESS', 'GREATER',
'COMMA', 'SEMI', 'COLON', 'DBLCOLON',
'ASTERISK',
# C preprocessor directives
'CPPDIRECTIVE'
)
# Regular expressions for token matching
t_LPAREN = r'\('
t_RPAREN = r'\)'
# not used any more... commented out to suppress PLY warning
# t_LBRACKET = r'\['
# t_RBRACKET = r'\]'
t_LBRACE = r'\{'
t_RBRACE = r'\}'
t_LESS = r'\<'
t_GREATER = r'\>'
t_COMMA = r','
t_SEMI = r';'
t_COLON = r':'
t_DBLCOLON = r'::'
t_ASTERISK = r'\*'
# Identifiers and reserved words
reserved_map = { }
for r in reserved:
reserved_map[r.lower()] = r
def t_ID(t):
r'[A-Za-z_]\w*'
t.type = reserved_map.get(t.value,'ID')
return t
# Integer literal
def t_INTLIT(t):
r'(0x[\da-fA-F]+)|\d+'
try:
t.value = int(t.value,0)
except ValueError:
error(t.lineno, 'Integer value "%s" too large' % t.value)
t.value = 0
return t
# String literal. Note that these use only single quotes, and
# can span multiple lines.
def t_STRLIT(t):
r"(?m)'([^'])+'"
# strip off quotes
t.value = t.value[1:-1]
t.lineno += t.value.count('\n')
return t
# "Code literal"... like a string literal, but delimiters are
# '{{' and '}}' so they get formatted nicely under emacs c-mode
def t_CODELIT(t):
r"(?m)\{\{([^\}]|}(?!\}))+\}\}"
# strip off {{ & }}
t.value = t.value[2:-2]
t.lineno += t.value.count('\n')
return t
def t_CPPDIRECTIVE(t):
r'^\#.*\n'
t.lineno += t.value.count('\n')
return t
#
# The functions t_NEWLINE, t_ignore, and t_error are
# special for the lex module.
#
# Newlines
def t_NEWLINE(t):
r'\n+'
t.lineno += t.value.count('\n')
# Comments
def t_comment(t):
r'//.*'
# Completely ignored characters
t_ignore = ' \t\x0c'
# Error handler
def t_error(t):
error(t.lineno, "illegal character '%s'" % t.value[0])
t.skip(1)
# Build the lexer
lex.lex()
#####################################################################
#
# Parser
#
# Every function whose name starts with 'p_' defines a grammar rule.
# The rule is encoded in the function's doc string, while the
# function body provides the action taken when the rule is matched.
# The argument to each function is a list of the values of the
# rule's symbols: t[0] for the LHS, and t[1..n] for the symbols
# on the RHS. For tokens, the value is copied from the t.value
# attribute provided by the lexer. For non-terminals, the value
# is assigned by the producing rule; i.e., the job of the grammar
# rule function is to set the value for the non-terminal on the LHS
# (by assigning to t[0]).
#####################################################################
# Not sure why, but we get a handful of shift/reduce conflicts on DECLARE.
# By default these get resolved as shifts, which is correct, but
# warnings are printed. Explicitly marking DECLARE as right-associative
# suppresses the warnings.
precedence = (
('right', 'DECLARE'),
)
# The LHS of the first grammar rule is used as the start symbol
# (in this case, 'specification'). Note that this rule enforces
# that there will be exactly one namespace declaration, with 0 or more
# global defs/decls before and after it. The defs & decls before
# the namespace decl will be outside the namespace; those after
# will be inside. The decoder function is always inside the namespace.
def p_specification(t):
'specification : opt_defs_and_declares name_decl opt_defs_and_declares decode_block'
global_decls1 = t[1]
isa_name = t[2]
namespace = isa_name + "Inst"
global_decls2 = t[3]
(inst_decls, decode_code, exec_code) = t[4]
decode_code = indent(decode_code)
# grab the last three path components of isa_desc_filename
filename = '/'.join(isa_desc_filename.split('/')[-3:])
# if the isa_desc file defines a 'rcs_id' string,
# echo that into the output too
try:
local_rcs_id = rcs_id
# strip $s out of ID so it doesn't get re-substituted
local_rcs_id = re.sub(r'\$', '', local_rcs_id)
except NameError:
local_rcs_id = 'Id: no RCS id found'
output = open(decoder_filename, 'w')
# split string to keep rcs from substituting this file's RCS id in
print >> output, '/* $Id' + '''$ */
/*
* Copyright (c) 2003
* The Regents of The University of Michigan
* All Rights Reserved
*
* This code is part of the M5 simulator, developed by Nathan Binkert,
* Erik Hallnor, Steve Raasch, and Steve Reinhardt, with contributions
* from Ron Dreslinski, Dave Greene, and Lisa Hsu.
*
* Permission is granted to use, copy, create derivative works and
* redistribute this software and such derivative works for any
* purpose, so long as the copyright notice above, this grant of
* permission, and the disclaimer below appear in all copies made; and
* so long as the name of The University of Michigan is not used in
* any advertising or publicity pertaining to the use or distribution
* of this software without specific, written prior authorization.
*
* THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE
* UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND
* WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE
* LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT,
* INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM
* ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
* IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGES.
*/
/*
* DO NOT EDIT THIS FILE!!!
*
* It was automatically generated from this ISA description:
* Filename: %(filename)s
* RCS %(local_rcs_id)s
*/
#include "base/bitfield.hh" // required for bitfield support
/////////////////////////////////////
// Global defs (outside namespace) //
/////////////////////////////////////
%(global_decls1)s
/**
* Namespace for %(isa_name)s static instruction objects.
*/
namespace %(namespace)s
{
/////////////////////////////////////
// Global defs (within namespace) //
/////////////////////////////////////
%(global_decls2)s
////////////////////////////////////
// Declares from inst definitions //
////////////////////////////////////
%(inst_decls)s
%(exec_code)s
} // namespace %(namespace)s
//////////////////////
// Decoder function //
//////////////////////
StaticInstPtr<%(isa_name)s>
%(isa_name)s::decodeInst(%(isa_name)s::MachInst machInst)
{
using namespace %(namespace)s;
%(decode_code)s
} // decodeInst
''' % vars()
output.close()
# ISA name declaration looks like "namespace <foo>;"
def p_name_decl(t):
'name_decl : NAMESPACE ID SEMI'
t[0] = t[2]
# 'opt_defs_and_declares' is a possibly empty sequence of
# defs and/or declares.
def p_opt_defs_and_declares_0(t):
'opt_defs_and_declares : empty'
t[0] = ''
def p_opt_defs_and_declares_1(t):
'opt_defs_and_declares : defs_and_declares'
t[0] = t[1]
def p_defs_and_declares_0(t):
'defs_and_declares : def_or_declare'
t[0] = t[1]
def p_defs_and_declares_1(t):
'defs_and_declares : defs_and_declares def_or_declare'
t[0] = t[1] + t[2]
# The list of possible definition/declaration statements.
def p_def_or_declare(t):
'''def_or_declare : def_format
| def_bitfield
| def_template
| global_declare
| global_let
| cpp_directive'''
t[0] = t[1]
# preprocessor directives are copied directly to the output.
def p_cpp_directive(t):
'''cpp_directive : CPPDIRECTIVE'''
t[0] = t[1]
# Global declares 'declare {{...}}' (C++ code blocks) are copied
# directly to the output.
def p_global_declare(t):
'global_declare : DECLARE CODELIT SEMI'
t[0] = substBitOps(t[2])
# global let blocks 'let {{...}}' (Python code blocks) are executed
# directly when seen. These are typically used to initialize global
# Python variables used in later format definitions.
def p_global_let(t):
'global_let : LET CODELIT SEMI'
try:
exec(fixPythonIndentation(t[2]))
except:
error_bt(t.lineno(1), 'error in global let block "%s".' % t[2])
t[0] = '' # contributes nothing to the output C++ file
# A bitfield definition looks like:
# 'def [signed] bitfield <ID> [<first>:<last>]'
# This generates a preprocessor macro in the output file.
def p_def_bitfield_0(t):
'def_bitfield : DEF opt_signed BITFIELD ID LESS INTLIT COLON INTLIT GREATER SEMI'
expr = 'bits(machInst, %2d, %2d)' % (t[6], t[8])
if (t[2] == 'signed'):
expr = 'sext<%d>(%s)' % (t[6] - t[8] + 1, expr)
t[0] = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr)
# alternate form for single bit: 'def [signed] bitfield <ID> [<bit>]'
def p_def_bitfield_1(t):
'def_bitfield : DEF opt_signed BITFIELD ID LESS INTLIT GREATER SEMI'
expr = 'bits(machInst, %2d, %2d)' % (t[6], t[6])
if (t[2] == 'signed'):
expr = 'sext<%d>(%s)' % (1, expr)
t[0] = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr)
def p_opt_signed_0(t):
'opt_signed : SIGNED'
t[0] = t[1]
def p_opt_signed_1(t):
'opt_signed : empty'
t[0] = ''
# Global map variable to hold templates
templateMap = {}
def p_def_template(t):
'def_template : DEF TEMPLATE ID CODELIT SEMI'
templateMap[t[3]] = t[4]
t[0] = ''
# An instruction format definition looks like
# "def format <fmt>(<params>) {{...}};"
def p_def_format(t):
'def_format : DEF FORMAT ID LPAREN param_list RPAREN CODELIT SEMI'
(id, params, code) = (t[3], t[5], t[7])
defFormat(id, params, code, t.lineno(1))
# insert a comment into the output to note that the def was processed
t[0] = '''
//
// parser: format %s defined
//
''' % id
# The formal parameter list for an instruction format is a possibly
# empty list of comma-separated parameters.
def p_param_list_0(t):
'param_list : empty'
t[0] = [ ]
def p_param_list_1(t):
'param_list : param'
t[0] = [t[1]]
def p_param_list_2(t):
'param_list : param_list COMMA param'
t[0] = t[1]
t[0].append(t[3])
# Each formal parameter is either an identifier or an identifier
# preceded by an asterisk. As in Python, the latter (if present) gets
# a tuple containing all the excess positional arguments, allowing
# varargs functions.
def p_param_0(t):
'param : ID'
t[0] = t[1]
def p_param_1(t):
'param : ASTERISK ID'
# just concatenate them: '*ID'
t[0] = t[1] + t[2]
# End of format definition-related rules.
##############
#
# A decode block looks like:
# decode <field1> [, <field2>]* [default <inst>] { ... }
#
def p_decode_block(t):
'decode_block : DECODE ID opt_default LBRACE decode_stmt_list RBRACE'
default_defaults = defaultStack.pop()
(decls, decode_code, exec_code, has_default) = t[5]
# use the "default defaults" only if there was no explicit
# default statement in decode_stmt_list
if not has_default:
(default_decls, default_decode, default_exec) = default_defaults
decls += default_decls
decode_code += default_decode
exec_code += default_exec
t[0] = (decls, '''
switch (%s) {
%s
}
''' % (t[2], indent(decode_code)), exec_code)
# The opt_default statement serves only to push the "default defaults"
# onto defaultStack. This value will be used by nested decode blocks,
# and used and popped off when the current decode_block is processed
# (in p_decode_block() above).
def p_opt_default_0(t):
'opt_default : empty'
# no default specified: reuse the one currently at the top of the stack
defaultStack.push(defaultStack.top())
# no meaningful value returned
t[0] = None
def p_opt_default_1(t):
'opt_default : DEFAULT inst'
# push the new default
(decls, decode_code, exec_code) = t[2]
defaultStack.push((decls, '\ndefault:\n%sbreak;' % decode_code, exec_code))
# no meaningful value returned
t[0] = None
def p_decode_stmt_list_0(t):
'decode_stmt_list : decode_stmt'
t[0] = t[1]
def p_decode_stmt_list_1(t):
'decode_stmt_list : decode_stmt decode_stmt_list'
(decls1, decode_code1, exec_code1, has_default1) = t[1]
(decls2, decode_code2, exec_code2, has_default2) = t[2]
if (has_default1 and has_default2):
error(t.lineno(1), 'Two default cases in decode block')
t[0] = (decls1 + '\n' + decls2, decode_code1 + '\n' + decode_code2,
exec_code1 + '\n' + exec_code2, has_default1 or has_default2)
#
# Decode statement rules
#
# There are four types of statements allowed in a decode block:
# 1. Format blocks 'format <foo> { ... }'
# 2. Nested decode blocks
# 3. Instruction definitions.
# 4. C preprocessor directives.
# Preprocessor directives found in a decode statement list are passed
# through to the output, replicated to both the declaration and decode
# streams. This works well for ifdefs, so we can ifdef out both the
# declarations and the decode cases generated by an instruction
# definition. Handling them as part of the grammar makes it easy to
# keep them in the right place with respect to the code generated by
# the other statements.
def p_decode_stmt_cpp(t):
'decode_stmt : CPPDIRECTIVE'
t[0] = (t[1], t[1], t[1], 0)
# A format block 'format <foo> { ... }' sets the default instruction
# format used to handle instruction definitions inside the block.
# This format can be overridden by using an explicit format on the
# instruction definition or with a nested format block.
def p_decode_stmt_format(t):
'decode_stmt : FORMAT push_format_id LBRACE decode_stmt_list RBRACE'
# The format will be pushed on the stack when 'push_format_id' is
# processed (see below). Once the parser has recognized the full
# production (though the right brace), we're done with the format,
# so now we can pop it.
formatStack.pop()
t[0] = t[4]
# This rule exists so we can set the current format (& push the stack)
# when we recognize the format name part of the format block.
def p_push_format_id(t):
'push_format_id : ID'
try:
formatStack.push(formatMap[t[1]])
t[0] = ('', '// format %s' % t[1])
except KeyError:
error(t.lineno(1), 'instruction format "%s" not defined.' % t[1])
# Nested decode block: if the value of the current field matches the
# specified constant, do a nested decode on some other field.
def p_decode_stmt_decode(t):
'decode_stmt : case_label COLON decode_block'
(label, is_default) = t[1]
(decls, decode_code, exec_code) = t[3]
# just wrap the decoding code from the block as a case in the
# outer switch statement.
t[0] = (decls, '\n%s:\n%s' % (label, indent(decode_code)),
exec_code, is_default)
# Instruction definition (finally!).
def p_decode_stmt_inst(t):
'decode_stmt : case_label COLON inst SEMI'
(label, is_default) = t[1]
(decls, decode_code, exec_code) = t[3]
t[0] = (decls, '\n%s:%sbreak;' % (label, indent(decode_code)),
exec_code, is_default)
# The case label is either a list of one or more constants or 'default'
def p_case_label_0(t):
'case_label : intlit_list'
t[0] = (': '.join(map(lambda a: 'case %#x' % a, t[1])), 0)
def p_case_label_1(t):
'case_label : DEFAULT'
t[0] = ('default', 1)
#
# The constant list for a decode case label must be non-empty, but may have
# one or more comma-separated integer literals in it.
#
def p_intlit_list_0(t):
'intlit_list : INTLIT'
t[0] = [t[1]]
def p_intlit_list_1(t):
'intlit_list : intlit_list COMMA INTLIT'
t[0] = t[1]
t[0].append(t[3])
# Define an instruction using the current instruction format (specified
# by an enclosing format block).
# "<mnemonic>(<args>)"
def p_inst_0(t):
'inst : ID LPAREN arg_list RPAREN'
# Pass the ID and arg list to the current format class to deal with.
currentFormat = formatStack.top()
(decls, decode_code, exec_code) = \
currentFormat.defineInst(t[1], t[3], t.lineno(1))
args = ','.join(map(str, t[3]))
args = re.sub('(?m)^', '//', args)
args = re.sub('^//', '', args)
comment = '// %s::%s(%s)\n' % (currentFormat.id, t[1], args)
t[0] = (comment + decls, comment + decode_code, comment + exec_code)
# Define an instruction using an explicitly specified format:
# "<fmt>::<mnemonic>(<args>)"
def p_inst_1(t):
'inst : ID DBLCOLON ID LPAREN arg_list RPAREN'
try:
format = formatMap[t[1]]
except KeyError:
error(t.lineno(1), 'instruction format "%s" not defined.' % t[1])
(decls, decode_code, exec_code) = \
format.defineInst(t[3], t[5], t.lineno(1))
comment = '// %s::%s(%s)\n' % (t[1], t[3], t[5])
t[0] = (comment + decls, comment + decode_code, comment + exec_code)
def p_arg_list_0(t):
'arg_list : empty'
t[0] = [ ]
def p_arg_list_1(t):
'arg_list : arg'
t[0] = [t[1]]
def p_arg_list_2(t):
'arg_list : arg_list COMMA arg'
t[0] = t[1]
t[0].append(t[3])
def p_arg(t):
'''arg : ID
| INTLIT
| STRLIT
| CODELIT'''
t[0] = t[1]
#
# Empty production... use in other rules for readability.
#
def p_empty(t):
'empty :'
pass
# Parse error handler. Note that the argument here is the offending
# *token*, not a grammar symbol (hence the need to use t.value)
def p_error(t):
if t:
error(t.lineno, "syntax error at '%s'" % t.value)
else:
error_bt(0, "unknown syntax error")
# END OF GRAMMAR RULES
#
# Now build the parser.
yacc.yacc()
################
# Format object.
#
# A format object encapsulates an instruction format. It must provide
# a defineInst() method that generates the code for an instruction
# definition.
class Format:
def __init__(self, id, params, code):
# constructor: just save away arguments
self.id = id
self.params = params
# strip blank lines from code (ones at the end are troublesome)
code = re.sub(r'(?m)^\s*$', '', code);
if code == '':
code = ' pass\n'
param_list = string.join(params, ", ")
f = 'def defInst(name, Name, ' + param_list + '):\n' + code
c = compile(f, 'def format ' + id, 'exec')
exec(c)
self.func = defInst
def defineInst(self, name, args, lineno):
# automatically provide a capitalized version of mnemonic
Name = string.capitalize(name)
try:
retval = self.func(name, Name, *args)
except:
error_bt(lineno, 'error defining "%s".' % name)
return retval
# Special null format to catch an implicit-format instruction
# definition outside of any format block.
class NoFormat:
def __init__(self):
self.defaultInst = ''
def defineInst(self, name, args, lineno):
error(lineno,
'instruction definition "%s" with no active format!' % name)
# This dictionary maps format name strings to Format objects.
formatMap = {}
# Define a new format
def defFormat(id, params, code, lineno):
# make sure we haven't already defined this one
if formatMap.get(id, None) != None:
error(lineno, 'format %s redefined.' % id)
# create new object and store in global map
formatMap[id] = Format(id, params, code)
##############
# Stack: a simple stack object. Used for both formats (formatStack)
# and default cases (defaultStack).
class Stack:
def __init__(self, initItem):
self.stack = [ initItem ]
def push(self, item):
self.stack.append(item);
def pop(self):
return self.stack.pop()
def top(self):
return self.stack[-1]
# The global format stack.
formatStack = Stack(NoFormat())
# The global default case stack.
defaultStack = Stack( None )
###################
# Utility functions
#
# Indent every line in string 's' by two spaces
# (except preprocessor directives).
# Used to make nested code blocks look pretty.
#
def indent(s):
return re.sub(r'(?m)^(?!\#)', ' ', s)
#
# Munge a somewhat arbitrarily formatted piece of Python code
# (e.g. from a format 'let' block) into something whose indentation
# will get by the Python parser.
#
# The two keys here are that Python will give a syntax error if
# there's any whitespace at the beginning of the first line, and that
# all lines at the same lexical nesting level must have identical
# indentation. Unfortunately the way code literals work, an entire
# let block tends to have some initial indentation. Rather than
# trying to figure out what that is and strip it off, we prepend 'if
# 1:' to make the let code the nested block inside the if (and have
# the parser automatically deal with the indentation for us).
#
# We don't want to do this if (1) the code block is empty or (2) the
# first line of the block doesn't have any whitespace at the front.
def fixPythonIndentation(s):
# get rid of blank lines first
s = re.sub(r'(?m)^\s*\n', '', s);
if (s != '' and re.match(r'[ \t]', s[0])):
s = 'if 1:\n' + s
return s
# Error handler. Just call exit. Output formatted to work under
# Emacs compile-mode.
def error(lineno, string):
sys.exit("%s:%d: %s" % (isa_desc_filename, lineno, string))
# Like error(), but include a Python stack backtrace (for processing
# Python exceptions).
def error_bt(lineno, string):
traceback.print_exc()
print >> sys.stderr, "%s:%d: %s" % (isa_desc_filename, lineno, string)
sys.exit(1)
#####################################################################
#
# Bitfield Operator Support
#
#####################################################################
bitOp1ArgRE = re.compile(r'<\s*(\w+)\s*:\s*>')
bitOpWordRE = re.compile(r'(?<![\w\.])([\w\.]+)<\s*(\w+)\s*:\s*(\w+)\s*>')
bitOpExprRE = re.compile(r'\)<\s*(\w+)\s*:\s*(\w+)\s*>')
def substBitOps(code):
# first convert single-bit selectors to two-index form
# i.e., <n> --> <n:n>
code = bitOp1ArgRE.sub(r'<\1:\1>', code)
# simple case: selector applied to ID (name)
# i.e., foo<a:b> --> bits(foo, a, b)
code = bitOpWordRE.sub(r'bits(\1, \2, \3)', code)
# if selector is applied to expression (ending in ')'),
# we need to search backward for matching '('
match = bitOpExprRE.search(code)
while match:
exprEnd = match.start()
here = exprEnd - 1
nestLevel = 1
while nestLevel > 0:
if code[here] == '(':
nestLevel -= 1
elif code[here] == ')':
nestLevel += 1
here -= 1
if here < 0:
sys.exit("Didn't find '('!")
exprStart = here+1
newExpr = r'bits(%s, %s, %s)' % (code[exprStart:exprEnd+1],
match.group(1), match.group(2))
code = code[:exprStart] + newExpr + code[match.end():]
match = bitOpExprRE.search(code)
return code
#####################################################################
#
# Code Parser
#
# The remaining code is the support for automatically extracting
# instruction characteristics from pseudocode.
#
#####################################################################
# Force the argument to be a list
def makeList(list_or_item):
if not list_or_item:
return []
elif type(list_or_item) == ListType:
return list_or_item
else:
return [ list_or_item ]
# generate operandSizeMap based on provided operandTypeMap:
# basically generate equiv. C++ type and make is_signed flag
def buildOperandSizeMap():
global operandSizeMap
operandSizeMap = {}
for ext in operandTypeMap.keys():
(desc, size) = operandTypeMap[ext]
if desc == 'signed int':
type = 'int%d_t' % size
is_signed = 1
elif desc == 'unsigned int':
type = 'uint%d_t' % size
is_signed = 0
elif desc == 'float':
is_signed = 1 # shouldn't really matter
if size == 32:
type = 'float'
elif size == 64:
type = 'double'
if type == '':
error(0, 'Unrecognized type description "%s" in operandTypeMap')
operandSizeMap[ext] = (size, type, is_signed)
#
# Base class for operand traits. An instance of this class (or actually
# a class derived from this one) encapsulates the traits of a particular
# operand type (e.g., "32-bit integer register").
#
class OperandTraits:
def __init__(self, dflt_ext, reg_spec, flags, sort_pri):
# Force construction of operandSizeMap from operandTypeMap
# if it hasn't happened yet
if not globals().has_key('operandSizeMap'):
buildOperandSizeMap()
self.dflt_ext = dflt_ext
(self.dflt_size, self.dflt_type, self.dflt_is_signed) = \
operandSizeMap[dflt_ext]
self.reg_spec = reg_spec
# Canonical flag structure is a triple of lists, where each list
# indicates the set of flags implied by this operand always, when
# used as a source, and when used as a dest, respectively.
# For simplicity this can be initialized using a variety of fairly
# obvious shortcuts; we convert these to canonical form here.
if not flags:
# no flags specified (e.g., 'None')
self.flags = ( [], [], [] )
elif type(flags) == StringType:
# a single flag: assumed to be unconditional
self.flags = ( [ flags ], [], [] )
elif type(flags) == ListType:
# a list of flags: also assumed to be unconditional
self.flags = ( flags, [], [] )
elif type(flags) == TupleType:
# it's a tuple: it should be a triple,
# but each item could be a single string or a list
(uncond_flags, src_flags, dest_flags) = flags
self.flags = (makeList(uncond_flags),
makeList(src_flags), makeList(dest_flags))
self.sort_pri = sort_pri
def isMem(self):
return 0
def isReg(self):
return 0
def isFloatReg(self):
return 0
def isIntReg(self):
return 0
def isControlReg(self):
return 0
def getFlags(self, op_desc):
# note the empty slice '[:]' gives us a copy of self.flags[0]
# instead of a reference to it
my_flags = self.flags[0][:]
if op_desc.is_src:
my_flags += self.flags[1]
if op_desc.is_dest:
my_flags += self.flags[2]
return my_flags
def makeDecl(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
# Note that initializations in the declarations are solely
# to avoid 'uninitialized variable' errors from the compiler.
return type + ' ' + op_desc.munged_name + ' = 0;\n';
class IntRegOperandTraits(OperandTraits):
def isReg(self):
return 1
def isIntReg(self):
return 1
def makeConstructor(self, op_desc):
c = ''
if op_desc.is_src:
c += '\n\t_srcRegIdx[%d] = %s;' % \
(op_desc.src_reg_idx, self.reg_spec)
if op_desc.is_dest:
c += '\n\t_destRegIdx[%d] = %s;' % \
(op_desc.dest_reg_idx, self.reg_spec)
return c
def makeRead(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
if (type == 'float' or type == 'double'):
error(0, 'Attempt to read integer register as FP')
if (size == self.dflt_size):
return '%s = xc->readIntReg(_srcRegIdx[%d]);\n' % \
(op_desc.munged_name, op_desc.src_reg_idx)
else:
return '%s = bits(xc->readIntReg(_srcRegIdx[%d]), %d, 0);\n' % \
(op_desc.munged_name, op_desc.src_reg_idx, size-1)
def makeWrite(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
if (type == 'float' or type == 'double'):
error(0, 'Attempt to write integer register as FP')
if (size != self.dflt_size and is_signed):
final_val = 'sext<%d>(%s)' % (size, op_desc.munged_name)
else:
final_val = op_desc.munged_name
wb = '''
{
%s final_val = %s;
xc->setIntReg(_destRegIdx[%d], final_val);\n
if (traceData) { traceData->setData(final_val); }
}''' % (self.dflt_type, final_val, op_desc.dest_reg_idx)
return wb
class FloatRegOperandTraits(OperandTraits):
def isReg(self):
return 1
def isFloatReg(self):
return 1
def makeConstructor(self, op_desc):
c = ''
if op_desc.is_src:
c += '\n\t_srcRegIdx[%d] = %s + FP_Base_DepTag;' % \
(op_desc.src_reg_idx, self.reg_spec)
if op_desc.is_dest:
c += '\n\t_destRegIdx[%d] = %s + FP_Base_DepTag;' % \
(op_desc.dest_reg_idx, self.reg_spec)
return c
def makeRead(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
bit_select = 0
if (type == 'float'):
func = 'readFloatRegSingle'
elif (type == 'double'):
func = 'readFloatRegDouble'
else:
func = 'readFloatRegInt'
if (size != self.dflt_size):
bit_select = 1
base = 'xc->%s(_srcRegIdx[%d] - FP_Base_DepTag)' % \
(func, op_desc.src_reg_idx)
if bit_select:
return '%s = bits(%s, %d, 0);\n' % \
(op_desc.munged_name, base, size-1)
else:
return '%s = %s;\n' % (op_desc.munged_name, base)
def makeWrite(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
final_val = op_desc.munged_name
if (type == 'float'):
func = 'setFloatRegSingle'
elif (type == 'double'):
func = 'setFloatRegDouble'
else:
func = 'setFloatRegInt'
type = 'uint%d_t' % self.dflt_size
if (size != self.dflt_size and is_signed):
final_val = 'sext<%d>(%s)' % (size, op_desc.munged_name)
wb = '''
{
%s final_val = %s;
xc->%s(_destRegIdx[%d] - FP_Base_DepTag, final_val);\n
if (traceData) { traceData->setData(final_val); }
}''' % (type, final_val, func, op_desc.dest_reg_idx)
return wb
class ControlRegOperandTraits(OperandTraits):
def isReg(self):
return 1
def isControlReg(self):
return 1
def makeConstructor(self, op_desc):
c = ''
if op_desc.is_src:
c += '\n\t_srcRegIdx[%d] = %s_DepTag;' % \
(op_desc.src_reg_idx, self.reg_spec)
if op_desc.is_dest:
c += '\n\t_destRegIdx[%d] = %s_DepTag;' % \
(op_desc.dest_reg_idx, self.reg_spec)
return c
def makeRead(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
bit_select = 0
if (type == 'float' or type == 'double'):
error(0, 'Attempt to read control register as FP')
base = 'xc->read%s()' % self.reg_spec
if size == self.dflt_size:
return '%s = %s;\n' % (op_desc.munged_name, base)
else:
return '%s = bits(%s, %d, 0);\n' % \
(op_desc.munged_name, base, size-1)
def makeWrite(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
if (type == 'float' or type == 'double'):
error(0, 'Attempt to write control register as FP')
wb = 'xc->set%s(%s);\n' % (self.reg_spec, op_desc.munged_name)
wb += 'if (traceData) { traceData->setData(%s); }' % \
op_desc.munged_name
return wb
class MemOperandTraits(OperandTraits):
def isMem(self):
return 1
def makeConstructor(self, op_desc):
return ''
def makeDecl(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
# Note that initializations in the declarations are solely
# to avoid 'uninitialized variable' errors from the compiler.
# Declare memory data variable.
c = '%s %s = 0;\n' % (type, op_desc.munged_name)
# Declare var to hold memory access flags.
c += 'unsigned %s_flags = memAccessFlags;\n' % op_desc.base_name
# If this operand is a dest (i.e., it's a store operation),
# then we need to declare a variable for the write result code
# as well.
if op_desc.is_dest:
c += 'uint64_t %s_write_result = 0;\n' % op_desc.base_name
return c
def makeRead(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
eff_type = 'uint%d_t' % size
return 'fault = xc->read(EA, (%s&)%s, %s_flags);\n' \
% (eff_type, op_desc.munged_name, op_desc.base_name)
def makeWrite(self, op_desc):
(size, type, is_signed) = operandSizeMap[op_desc.eff_ext]
eff_type = 'uint%d_t' % size
return 'fault = xc->write((%s&)%s, EA, %s_flags,' \
' &%s_write_result);\n' \
% (eff_type, op_desc.munged_name, op_desc.base_name,
op_desc.base_name)
class NPCOperandTraits(OperandTraits):
def makeConstructor(self, op_desc):
return ''
def makeRead(self, op_desc):
return '%s = xc->readPC() + 4;\n' % op_desc.munged_name
def makeWrite(self, op_desc):
return 'xc->setNextPC(%s);\n' % op_desc.munged_name
#
# Define operand variables that get derived from the basic declaration
# of ISA-specific operands in operandTraitsMap. This function must be
# called by the ISA description file explicitly after defining
# operandTraitsMap (in a 'let' block).
#
def defineDerivedOperandVars():
global operands
operands = operandTraitsMap.keys()
operandsREString = (r'''
(?<![\w\.]) # neg. lookbehind assertion: prevent partial matches
((%s)(?:\.(\w+))?) # match: operand with optional '.' then suffix
(?![\w\.]) # neg. lookahead assertion: prevent partial matches
'''
% string.join(operands, '|'))
global operandsRE
operandsRE = re.compile(operandsREString, re.MULTILINE|re.VERBOSE)
# Same as operandsREString, but extension is mandatory, and only two
# groups are returned (base and ext, not full name as above).
# Used for subtituting '_' for '.' to make C++ identifiers.
operandsWithExtREString = (r'(?<![\w\.])(%s)\.(\w+)(?![\w\.])'
% string.join(operands, '|'))
global operandsWithExtRE
operandsWithExtRE = re.compile(operandsWithExtREString, re.MULTILINE)
#
# Operand descriptor class. An instance of this class represents
# a specific operand for a code block.
#
class OperandDescriptor:
def __init__(self, full_name, base_name, ext, is_src, is_dest):
self.full_name = full_name
self.base_name = base_name
self.ext = ext
self.is_src = is_src
self.is_dest = is_dest
self.traits = operandTraitsMap[base_name]
# The 'effective extension' (eff_ext) is either the actual
# extension, if one was explicitly provided, or the default.
# The 'munged name' replaces the '.' between the base and
# extension (if any) with a '_' to make a legal C++ variable name.
if ext:
self.eff_ext = ext
self.munged_name = base_name + '_' + ext
else:
self.eff_ext = self.traits.dflt_ext
self.munged_name = base_name
# Finalize additional fields (primarily code fields). This step
# is done separately since some of these fields may depend on the
# register index enumeration that hasn't been performed yet at the
# time of __init__().
def finalize(self):
self.flags = self.traits.getFlags(self)
self.constructor = self.traits.makeConstructor(self)
self.op_decl = self.traits.makeDecl(self)
if self.is_src:
self.op_rd = self.traits.makeRead(self)
else:
self.op_rd = ''
if self.is_dest:
self.op_wb = self.traits.makeWrite(self)
else:
self.op_wb = ''
class OperandDescriptorList:
def __init__(self):
self.items = []
self.bases = {}
def __len__(self):
return len(self.items)
def __getitem__(self, index):
return self.items[index]
def append(self, op_desc):
self.items.append(op_desc)
self.bases[op_desc.base_name] = op_desc
def find_base(self, base_name):
# like self.bases[base_name], but returns None if not found
# (rather than raising exception)
return self.bases.get(base_name)
# internal helper function for concat[Some]Attr{Strings|Lists}
def __internalConcatAttrs(self, attr_name, filter, result):
for op_desc in self.items:
if filter(op_desc):
result += getattr(op_desc, attr_name)
return result
# return a single string that is the concatenation of the (string)
# values of the specified attribute for all operands
def concatAttrStrings(self, attr_name):
return self.__internalConcatAttrs(attr_name, lambda x: 1, '')
# like concatAttrStrings, but only include the values for the operands
# for which the provided filter function returns true
def concatSomeAttrStrings(self, filter, attr_name):
return self.__internalConcatAttrs(attr_name, filter, '')
# return a single list that is the concatenation of the (list)
# values of the specified attribute for all operands
def concatAttrLists(self, attr_name):
return self.__internalConcatAttrs(attr_name, lambda x: 1, [])
# like concatAttrLists, but only include the values for the operands
# for which the provided filter function returns true
def concatSomeAttrLists(self, filter, attr_name):
return self.__internalConcatAttrs(attr_name, filter, [])
def sort(self):
self.items.sort(lambda a, b: a.traits.sort_pri - b.traits.sort_pri)
# Regular expression object to match C++ comments
# (used in findOperands())
commentRE = re.compile(r'//.*\n')
# Regular expression object to match assignment statements
# (used in findOperands())
assignRE = re.compile(r'\s*=(?!=)', re.MULTILINE)
#
# Find all the operands in the given code block. Returns an operand
# descriptor list (instance of class OperandDescriptorList).
#
def findOperands(code):
operands = OperandDescriptorList()
# delete comments so we don't accidentally match on reg specifiers inside
code = commentRE.sub('', code)
# search for operands
next_pos = 0
while 1:
match = operandsRE.search(code, next_pos)
if not match:
# no more matches: we're done
break
op = match.groups()
# regexp groups are operand full name, base, and extension
(op_full, op_base, op_ext) = op
# if the token following the operand is an assignment, this is
# a destination (LHS), else it's a source (RHS)
is_dest = (assignRE.match(code, match.end()) != None)
is_src = not is_dest
# see if we've already seen this one
op_desc = operands.find_base(op_base)
if op_desc:
if op_desc.ext != op_ext:
error(0, 'Inconsistent extensions for operand %s' % op_base)
op_desc.is_src = op_desc.is_src or is_src
op_desc.is_dest = op_desc.is_dest or is_dest
else:
# new operand: create new descriptor
op_desc = OperandDescriptor(op_full, op_base, op_ext,
is_src, is_dest)
operands.append(op_desc)
# start next search after end of current match
next_pos = match.end()
operands.sort()
# enumerate source & dest register operands... used in building
# constructor later
srcRegs = 0
destRegs = 0
operands.numFPDestRegs = 0
operands.numIntDestRegs = 0
for op_desc in operands:
if op_desc.traits.isReg():
if op_desc.is_src:
op_desc.src_reg_idx = srcRegs
srcRegs += 1
if op_desc.is_dest:
op_desc.dest_reg_idx = destRegs
destRegs += 1
if op_desc.traits.isFloatReg():
operands.numFPDestRegs += 1
elif op_desc.traits.isIntReg():
operands.numIntDestRegs += 1
operands.numSrcRegs = srcRegs
operands.numDestRegs = destRegs
# now make a final pass to finalize op_desc fields that may depend
# on the register enumeration
for op_desc in operands:
op_desc.finalize()
return operands
# Munge operand names in code string to make legal C++ variable names.
# (Will match munged_name attribute of OperandDescriptor object.)
def substMungedOpNames(code):
return operandsWithExtRE.sub(r'\1_\2', code)
def joinLists(t):
return map(string.join, t)
def makeFlagConstructor(flag_list):
if len(flag_list) == 0:
return ''
# filter out repeated flags
flag_list.sort()
i = 1
while i < len(flag_list):
if flag_list[i] == flag_list[i-1]:
del flag_list[i]
else:
i += 1
pre = '\n\tflags['
post = '] = true;'
code = pre + string.join(flag_list, post + pre) + post
return code
class CodeBlock:
def __init__(self, code):
self.orig_code = code
self.operands = findOperands(code)
self.code = substMungedOpNames(substBitOps(code))
self.constructor = self.operands.concatAttrStrings('constructor')
self.constructor += \
'\n\t_numSrcRegs = %d;' % self.operands.numSrcRegs
self.constructor += \
'\n\t_numDestRegs = %d;' % self.operands.numDestRegs
self.constructor += \
'\n\t_numFPDestRegs = %d;' % self.operands.numFPDestRegs
self.constructor += \
'\n\t_numIntDestRegs = %d;' % self.operands.numIntDestRegs
self.op_decl = self.operands.concatAttrStrings('op_decl')
is_mem = lambda op: op.traits.isMem()
not_mem = lambda op: not op.traits.isMem()
self.op_rd = self.operands.concatAttrStrings('op_rd')
self.op_wb = self.operands.concatAttrStrings('op_wb')
self.op_mem_rd = \
self.operands.concatSomeAttrStrings(is_mem, 'op_rd')
self.op_mem_wb = \
self.operands.concatSomeAttrStrings(is_mem, 'op_wb')
self.op_nonmem_rd = \
self.operands.concatSomeAttrStrings(not_mem, 'op_rd')
self.op_nonmem_wb = \
self.operands.concatSomeAttrStrings(not_mem, 'op_wb')
self.flags = self.operands.concatAttrLists('flags')
# Make a basic guess on the operand class (function unit type).
# These are good enough for most cases, and will be overridden
# later otherwise.
if 'IsStore' in self.flags:
self.op_class = 'WrPort'
elif 'IsLoad' in self.flags or 'IsPrefetch' in self.flags:
self.op_class = 'RdPort'
elif 'IsFloating' in self.flags:
self.op_class = 'FloatADD'
else:
self.op_class = 'IntALU'
# Assume all instruction flags are of the form 'IsFoo'
instFlagRE = re.compile(r'Is.*')
# OpClass constants are just a little more complicated
opClassRE = re.compile(r'Int.*|Float.*|.*Port|No_OpClass')
class InstObjParams:
def __init__(self, mnem, class_name, base_class = '',
code_block = None, opt_args = []):
self.mnemonic = mnem
self.class_name = class_name
self.base_class = base_class
self.exec_func_declarations = '''
Fault execute(SimpleCPUExecContext *, Trace::InstRecord *);
Fault execute(FullCPUExecContext *, Trace::InstRecord *);
'''
if code_block:
for code_attr in code_block.__dict__.keys():
setattr(self, code_attr, getattr(code_block, code_attr))
else:
self.constructor = ''
self.flags = []
# Optional arguments are assumed to be either StaticInst flags
# or an OpClass value. To avoid having to import a complete
# list of these values to match against, we do it ad-hoc
# with regexps.
for oa in opt_args:
if instFlagRE.match(oa):
self.flags.append(oa)
elif opClassRE.match(oa):
self.op_class = oa
else:
error(0, 'InstObjParams: optional arg "%s" not recognized '
'as StaticInst::Flag or OpClass.' % oa)
# add flag initialization to contructor here to include
# any flags added via opt_args
self.constructor += makeFlagConstructor(self.flags)
# if 'IsFloating' is set, add call to the FP enable check
# function (which should be provided by isa_desc via a declare)
if 'IsFloating' in self.flags:
self.fp_enable_check = 'fault = checkFpEnableFault(xc);'
else:
self.fp_enable_check = ''
def _subst(self, template):
try:
return template % self.__dict__
except KeyError, key:
raise KeyError, 'InstObjParams.subst: no definition for %s' % key
def subst(self, *args):
result = []
for t in args:
try: template = templateMap[t]
except KeyError:
error(0, 'InstObjParams::subst: undefined template "%s"' % t)
if template.find('%(cpu_model)') != -1:
tmp = ''
for cpu_model in ('SimpleCPUExecContext', 'FullCPUExecContext'):
self.cpu_model = cpu_model
tmp += self._subst(template)
result.append(tmp)
else:
result.append(self._subst(template))
if len(args) == 1:
result = result[0]
return result
#
# Read in and parse the ISA description.
#
def parse_isa_desc(isa_desc_file, decoder_file):
# Arguments are the name of the ISA description (input) file and
# the name of the C++ decoder (output) file.
global isa_desc_filename, decoder_filename
isa_desc_filename = isa_desc_file
decoder_filename = decoder_file
# Suck the ISA description file in.
input = open(isa_desc_filename)
isa_desc = input.read()
input.close()
# Parse it.
yacc.parse(isa_desc)
# Called as script: get args from command line.
if __name__ == '__main__':
parse_isa_desc(sys.argv[1], sys.argv[2])