gem5/src/arch/isa_parser.py
Gabe Black 997cbe1c09 ISA parser: Use '_' instead of '.' to delimit type modifiers on operands.
By using an underscore, the "." is still available and can unambiguously be
used to refer to members of a structure if an operand is a structure, class,
etc. This change mostly just replaces the appropriate "."s with "_"s, but
there were also a few places where the ISA descriptions where handling the
extensions themselves and had their own regular expressions to update. The
regular expressions in the isa parser were updated as well. It also now
looks for one of the defined type extensions specifically after connecting "_"
where before it would look for any sequence of characters after a "."
following an operand name and try to use it as the extension. This helps to
disambiguate cases where a "_" may legitimately be part of an operand name but
not separate the name from the type suffix.

Because leaving the "_" and suffix on the variable name still leaves a valid
C++ identifier and all extensions need to be consistent in a given context, I
considered leaving them on as a breadcrumb that would show what the intended
type was for that operand. Unfortunately the operands can be referred to in
code templates, the Mem operand in particular, and since the exact type of Mem
can be different for different uses of the same template, that broke things.
2011-09-26 23:48:54 -07:00

2009 lines
73 KiB
Python
Executable file

# Copyright (c) 2003-2005 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.
#
# Authors: Steve Reinhardt
import os
import sys
import re
import string
import inspect, traceback
# get type names
from types import *
from m5.util.grammar import Grammar
debug=False
###################
# 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
class ISAParserError(Exception):
"""Error handler for parser errors"""
def __init__(self, first, second=None):
if second is None:
self.lineno = 0
self.string = first
else:
if hasattr(first, 'lexer'):
first = first.lexer.lineno
self.lineno = first
self.string = second
def display(self, filename_stack, print_traceback=debug):
# Output formatted to work under Emacs compile-mode. Optional
# 'print_traceback' arg, if set to True, prints a Python stack
# backtrace too (can be handy when trying to debug the parser
# itself).
spaces = ""
for (filename, line) in filename_stack[:-1]:
print "%sIn file included from %s:" % (spaces, filename)
spaces += " "
# Print a Python stack backtrace if requested.
if print_traceback or not self.lineno:
traceback.print_exc()
line_str = "%s:" % (filename_stack[-1][0], )
if self.lineno:
line_str += "%d:" % (self.lineno, )
return "%s%s %s" % (spaces, line_str, self.string)
def exit(self, filename_stack, print_traceback=debug):
# Just call exit.
sys.exit(self.display(filename_stack, print_traceback))
def error(*args):
raise ISAParserError(*args)
####################
# Template objects.
#
# Template objects are format strings that allow substitution from
# the attribute spaces of other objects (e.g. InstObjParams instances).
labelRE = re.compile(r'(?<!%)%\(([^\)]+)\)[sd]')
class Template(object):
def __init__(self, parser, t):
self.parser = parser
self.template = t
def subst(self, d):
myDict = None
# Protect non-Python-dict substitutions (e.g. if there's a printf
# in the templated C++ code)
template = self.parser.protectNonSubstPercents(self.template)
# CPU-model-specific substitutions are handled later (in GenCode).
template = self.parser.protectCpuSymbols(template)
# Build a dict ('myDict') to use for the template substitution.
# Start with the template namespace. Make a copy since we're
# going to modify it.
myDict = self.parser.templateMap.copy()
if isinstance(d, InstObjParams):
# If we're dealing with an InstObjParams object, we need
# to be a little more sophisticated. The instruction-wide
# parameters are already formed, but the parameters which
# are only function wide still need to be generated.
compositeCode = ''
myDict.update(d.__dict__)
# The "operands" and "snippets" attributes of the InstObjParams
# objects are for internal use and not substitution.
del myDict['operands']
del myDict['snippets']
snippetLabels = [l for l in labelRE.findall(template)
if d.snippets.has_key(l)]
snippets = dict([(s, self.parser.mungeSnippet(d.snippets[s]))
for s in snippetLabels])
myDict.update(snippets)
compositeCode = ' '.join(map(str, snippets.values()))
# Add in template itself in case it references any
# operands explicitly (like Mem)
compositeCode += ' ' + template
operands = SubOperandList(self.parser, compositeCode, d.operands)
myDict['op_decl'] = operands.concatAttrStrings('op_decl')
if operands.readPC or operands.setPC:
myDict['op_decl'] += 'TheISA::PCState __parserAutoPCState;\n'
is_src = lambda op: op.is_src
is_dest = lambda op: op.is_dest
myDict['op_src_decl'] = \
operands.concatSomeAttrStrings(is_src, 'op_src_decl')
myDict['op_dest_decl'] = \
operands.concatSomeAttrStrings(is_dest, 'op_dest_decl')
if operands.readPC:
myDict['op_src_decl'] += \
'TheISA::PCState __parserAutoPCState;\n'
if operands.setPC:
myDict['op_dest_decl'] += \
'TheISA::PCState __parserAutoPCState;\n'
myDict['op_rd'] = operands.concatAttrStrings('op_rd')
if operands.readPC:
myDict['op_rd'] = '__parserAutoPCState = xc->pcState();\n' + \
myDict['op_rd']
# Compose the op_wb string. If we're going to write back the
# PC state because we changed some of its elements, we'll need to
# do that as early as possible. That allows later uncoordinated
# modifications to the PC to layer appropriately.
reordered = list(operands.items)
reordered.reverse()
op_wb_str = ''
pcWbStr = 'xc->pcState(__parserAutoPCState);\n'
for op_desc in reordered:
if op_desc.isPCPart() and op_desc.is_dest:
op_wb_str = op_desc.op_wb + pcWbStr + op_wb_str
pcWbStr = ''
else:
op_wb_str = op_desc.op_wb + op_wb_str
myDict['op_wb'] = op_wb_str
elif isinstance(d, dict):
# if the argument is a dictionary, we just use it.
myDict.update(d)
elif hasattr(d, '__dict__'):
# if the argument is an object, we use its attribute map.
myDict.update(d.__dict__)
else:
raise TypeError, "Template.subst() arg must be or have dictionary"
return template % myDict
# Convert to string. This handles the case when a template with a
# CPU-specific term gets interpolated into another template or into
# an output block.
def __str__(self):
return self.parser.expandCpuSymbolsToString(self.template)
################
# 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(object):
def __init__(self, id, params, code):
self.id = id
self.params = params
label = 'def format ' + id
self.user_code = compile(fixPythonIndentation(code), label, 'exec')
param_list = string.join(params, ", ")
f = '''def defInst(_code, _context, %s):
my_locals = vars().copy()
exec _code in _context, my_locals
return my_locals\n''' % param_list
c = compile(f, label + ' wrapper', 'exec')
exec c
self.func = defInst
def defineInst(self, parser, name, args, lineno):
parser.updateExportContext()
context = parser.exportContext.copy()
if len(name):
Name = name[0].upper()
if len(name) > 1:
Name += name[1:]
context.update({ 'name' : name, 'Name' : Name })
try:
vars = self.func(self.user_code, context, *args[0], **args[1])
except Exception, exc:
if debug:
raise
error(lineno, 'error defining "%s": %s.' % (name, exc))
for k in vars.keys():
if k not in ('header_output', 'decoder_output',
'exec_output', 'decode_block'):
del vars[k]
return GenCode(parser, **vars)
# Special null format to catch an implicit-format instruction
# definition outside of any format block.
class NoFormat(object):
def __init__(self):
self.defaultInst = ''
def defineInst(self, parser, name, args, lineno):
error(lineno,
'instruction definition "%s" with no active format!' % name)
###############
# GenCode class
#
# The GenCode class encapsulates generated code destined for various
# output files. The header_output and decoder_output attributes are
# strings containing code destined for decoder.hh and decoder.cc
# respectively. The decode_block attribute contains code to be
# incorporated in the decode function itself (that will also end up in
# decoder.cc). The exec_output attribute is a dictionary with a key
# for each CPU model name; the value associated with a particular key
# is the string of code for that CPU model's exec.cc file. The
# has_decode_default attribute is used in the decode block to allow
# explicit default clauses to override default default clauses.
class GenCode(object):
# Constructor. At this point we substitute out all CPU-specific
# symbols. For the exec output, these go into the per-model
# dictionary. For all other output types they get collapsed into
# a single string.
def __init__(self, parser,
header_output = '', decoder_output = '', exec_output = '',
decode_block = '', has_decode_default = False):
self.parser = parser
self.header_output = parser.expandCpuSymbolsToString(header_output)
self.decoder_output = parser.expandCpuSymbolsToString(decoder_output)
if isinstance(exec_output, dict):
self.exec_output = exec_output
elif isinstance(exec_output, str):
# If the exec_output arg is a single string, we replicate
# it for each of the CPU models, substituting and
# %(CPU_foo)s params appropriately.
self.exec_output = parser.expandCpuSymbolsToDict(exec_output)
self.decode_block = parser.expandCpuSymbolsToString(decode_block)
self.has_decode_default = has_decode_default
# Override '+' operator: generate a new GenCode object that
# concatenates all the individual strings in the operands.
def __add__(self, other):
exec_output = {}
for cpu in self.parser.cpuModels:
n = cpu.name
exec_output[n] = self.exec_output[n] + other.exec_output[n]
return GenCode(self.parser,
self.header_output + other.header_output,
self.decoder_output + other.decoder_output,
exec_output,
self.decode_block + other.decode_block,
self.has_decode_default or other.has_decode_default)
# Prepend a string (typically a comment) to all the strings.
def prepend_all(self, pre):
self.header_output = pre + self.header_output
self.decoder_output = pre + self.decoder_output
self.decode_block = pre + self.decode_block
for cpu in self.parser.cpuModels:
self.exec_output[cpu.name] = pre + self.exec_output[cpu.name]
# Wrap the decode block in a pair of strings (e.g., 'case foo:'
# and 'break;'). Used to build the big nested switch statement.
def wrap_decode_block(self, pre, post = ''):
self.decode_block = pre + indent(self.decode_block) + post
#####################################################################
#
# 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. Useful for flags, where a caller
# can specify a singleton flag or a list of flags. Also usful for
# converting tuples to lists so they can be modified.
def makeList(arg):
if isinstance(arg, list):
return arg
elif isinstance(arg, tuple):
return list(arg)
elif not arg:
return []
else:
return [ arg ]
class Operand(object):
'''Base class for operand descriptors. An instance of this class
(or actually a class derived from this one) represents a specific
operand for a code block (e.g, "Rc.sq" as a dest). Intermediate
derived classes encapsulates the traits of a particular operand
type (e.g., "32-bit integer register").'''
def buildReadCode(self, func = None):
subst_dict = {"name": self.base_name,
"func": func,
"reg_idx": self.reg_spec,
"ctype": self.ctype}
if hasattr(self, 'src_reg_idx'):
subst_dict['op_idx'] = self.src_reg_idx
code = self.read_code % subst_dict
return '%s = %s;\n' % (self.base_name, code)
def buildWriteCode(self, func = None):
subst_dict = {"name": self.base_name,
"func": func,
"reg_idx": self.reg_spec,
"ctype": self.ctype,
"final_val": self.base_name}
if hasattr(self, 'dest_reg_idx'):
subst_dict['op_idx'] = self.dest_reg_idx
code = self.write_code % subst_dict
return '''
{
%s final_val = %s;
%s;
if (traceData) { traceData->setData(final_val); }
}''' % (self.dflt_ctype, self.base_name, code)
def __init__(self, parser, full_name, ext, is_src, is_dest):
self.full_name = full_name
self.ext = ext
self.is_src = is_src
self.is_dest = is_dest
# The 'effective extension' (eff_ext) is either the actual
# extension, if one was explicitly provided, or the default.
if ext:
self.eff_ext = ext
elif hasattr(self, 'dflt_ext'):
self.eff_ext = self.dflt_ext
if hasattr(self, 'eff_ext'):
self.ctype = parser.operandTypeMap[self.eff_ext]
# 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.getFlags()
self.constructor = self.makeConstructor()
self.op_decl = self.makeDecl()
if self.is_src:
self.op_rd = self.makeRead()
self.op_src_decl = self.makeDecl()
else:
self.op_rd = ''
self.op_src_decl = ''
if self.is_dest:
self.op_wb = self.makeWrite()
self.op_dest_decl = self.makeDecl()
else:
self.op_wb = ''
self.op_dest_decl = ''
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 isPCState(self):
return 0
def isPCPart(self):
return self.isPCState() and self.reg_spec
def getFlags(self):
# note the empty slice '[:]' gives us a copy of self.flags[0]
# instead of a reference to it
my_flags = self.flags[0][:]
if self.is_src:
my_flags += self.flags[1]
if self.is_dest:
my_flags += self.flags[2]
return my_flags
def makeDecl(self):
# Note that initializations in the declarations are solely
# to avoid 'uninitialized variable' errors from the compiler.
return self.ctype + ' ' + self.base_name + ' = 0;\n';
class IntRegOperand(Operand):
def isReg(self):
return 1
def isIntReg(self):
return 1
def makeConstructor(self):
c = ''
if self.is_src:
c += '\n\t_srcRegIdx[%d] = %s;' % \
(self.src_reg_idx, self.reg_spec)
if self.is_dest:
c += '\n\t_destRegIdx[%d] = %s;' % \
(self.dest_reg_idx, self.reg_spec)
return c
def makeRead(self):
if (self.ctype == 'float' or self.ctype == 'double'):
error('Attempt to read integer register as FP')
if self.read_code != None:
return self.buildReadCode('readIntRegOperand')
int_reg_val = 'xc->readIntRegOperand(this, %d)' % self.src_reg_idx
return '%s = %s;\n' % (self.base_name, int_reg_val)
def makeWrite(self):
if (self.ctype == 'float' or self.ctype == 'double'):
error('Attempt to write integer register as FP')
if self.write_code != None:
return self.buildWriteCode('setIntRegOperand')
wb = '''
{
%s final_val = %s;
xc->setIntRegOperand(this, %d, final_val);\n
if (traceData) { traceData->setData(final_val); }
}''' % (self.ctype, self.base_name, self.dest_reg_idx)
return wb
class FloatRegOperand(Operand):
def isReg(self):
return 1
def isFloatReg(self):
return 1
def makeConstructor(self):
c = ''
if self.is_src:
c += '\n\t_srcRegIdx[%d] = %s + FP_Base_DepTag;' % \
(self.src_reg_idx, self.reg_spec)
if self.is_dest:
c += '\n\t_destRegIdx[%d] = %s + FP_Base_DepTag;' % \
(self.dest_reg_idx, self.reg_spec)
return c
def makeRead(self):
bit_select = 0
if (self.ctype == 'float' or self.ctype == 'double'):
func = 'readFloatRegOperand'
else:
func = 'readFloatRegOperandBits'
if self.read_code != None:
return self.buildReadCode(func)
return '%s = xc->%s(this, %d);\n' % \
(self.base_name, func, self.src_reg_idx)
def makeWrite(self):
if (self.ctype == 'float' or self.ctype == 'double'):
func = 'setFloatRegOperand'
else:
func = 'setFloatRegOperandBits'
if self.write_code != None:
return self.buildWriteCode(func)
wb = '''
{
%s final_val = %s;
xc->%s(this, %d, final_val);\n
if (traceData) { traceData->setData(final_val); }
}''' % (self.ctype, self.base_name, func, self.dest_reg_idx)
return wb
class ControlRegOperand(Operand):
def isReg(self):
return 1
def isControlReg(self):
return 1
def makeConstructor(self):
c = ''
if self.is_src:
c += '\n\t_srcRegIdx[%d] = %s + Ctrl_Base_DepTag;' % \
(self.src_reg_idx, self.reg_spec)
if self.is_dest:
c += '\n\t_destRegIdx[%d] = %s + Ctrl_Base_DepTag;' % \
(self.dest_reg_idx, self.reg_spec)
return c
def makeRead(self):
bit_select = 0
if (self.ctype == 'float' or self.ctype == 'double'):
error('Attempt to read control register as FP')
if self.read_code != None:
return self.buildReadCode('readMiscRegOperand')
return '%s = xc->readMiscRegOperand(this, %s);\n' % \
(self.base_name, self.src_reg_idx)
def makeWrite(self):
if (self.ctype == 'float' or self.ctype == 'double'):
error('Attempt to write control register as FP')
if self.write_code != None:
return self.buildWriteCode('setMiscRegOperand')
wb = 'xc->setMiscRegOperand(this, %s, %s);\n' % \
(self.dest_reg_idx, self.base_name)
wb += 'if (traceData) { traceData->setData(%s); }' % \
self.base_name
return wb
class MemOperand(Operand):
def isMem(self):
return 1
def makeConstructor(self):
return ''
def makeDecl(self):
# Note that initializations in the declarations are solely
# to avoid 'uninitialized variable' errors from the compiler.
# Declare memory data variable.
return '%s %s = 0;\n' % (self.ctype, self.base_name)
def makeRead(self):
if self.read_code != None:
return self.buildReadCode()
return ''
def makeWrite(self):
if self.write_code != None:
return self.buildWriteCode()
return ''
class PCStateOperand(Operand):
def makeConstructor(self):
return ''
def makeRead(self):
if self.reg_spec:
# A component of the PC state.
return '%s = __parserAutoPCState.%s();\n' % \
(self.base_name, self.reg_spec)
else:
# The whole PC state itself.
return '%s = xc->pcState();\n' % self.base_name
def makeWrite(self):
if self.reg_spec:
# A component of the PC state.
return '__parserAutoPCState.%s(%s);\n' % \
(self.reg_spec, self.base_name)
else:
# The whole PC state itself.
return 'xc->pcState(%s);\n' % self.base_name
def makeDecl(self):
ctype = 'TheISA::PCState'
if self.isPCPart():
ctype = self.ctype
return "%s %s;\n" % (ctype, self.base_name)
def isPCState(self):
return 1
class OperandList(object):
'''Find all the operands in the given code block. Returns an operand
descriptor list (instance of class OperandList).'''
def __init__(self, parser, code):
self.items = []
self.bases = {}
# delete strings and comments so we don't match on operands inside
for regEx in (stringRE, commentRE):
code = regEx.sub('', code)
# search for operands
next_pos = 0
while 1:
match = parser.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 = self.find_base(op_base)
if op_desc:
if op_desc.ext != op_ext:
error('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 = parser.operandNameMap[op_base](parser,
op_full, op_ext, is_src, is_dest)
self.append(op_desc)
# start next search after end of current match
next_pos = match.end()
self.sort()
# enumerate source & dest register operands... used in building
# constructor later
self.numSrcRegs = 0
self.numDestRegs = 0
self.numFPDestRegs = 0
self.numIntDestRegs = 0
self.memOperand = None
for op_desc in self.items:
if op_desc.isReg():
if op_desc.is_src:
op_desc.src_reg_idx = self.numSrcRegs
self.numSrcRegs += 1
if op_desc.is_dest:
op_desc.dest_reg_idx = self.numDestRegs
self.numDestRegs += 1
if op_desc.isFloatReg():
self.numFPDestRegs += 1
elif op_desc.isIntReg():
self.numIntDestRegs += 1
elif op_desc.isMem():
if self.memOperand:
error("Code block has more than one memory operand.")
self.memOperand = op_desc
if parser.maxInstSrcRegs < self.numSrcRegs:
parser.maxInstSrcRegs = self.numSrcRegs
if parser.maxInstDestRegs < self.numDestRegs:
parser.maxInstDestRegs = self.numDestRegs
# now make a final pass to finalize op_desc fields that may depend
# on the register enumeration
for op_desc in self.items:
op_desc.finalize()
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.sort_pri - b.sort_pri)
class SubOperandList(OperandList):
'''Find all the operands in the given code block. Returns an operand
descriptor list (instance of class OperandList).'''
def __init__(self, parser, code, master_list):
self.items = []
self.bases = {}
# delete strings and comments so we don't match on operands inside
for regEx in (stringRE, commentRE):
code = regEx.sub('', code)
# search for operands
next_pos = 0
while 1:
match = parser.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
# find this op in the master list
op_desc = master_list.find_base(op_base)
if not op_desc:
error('Found operand %s which is not in the master list!' \
' This is an internal error' % op_base)
else:
# See if we've already found this operand
op_desc = self.find_base(op_base)
if not op_desc:
# if not, add a reference to it to this sub list
self.append(master_list.bases[op_base])
# start next search after end of current match
next_pos = match.end()
self.sort()
self.memOperand = None
# Whether the whole PC needs to be read so parts of it can be accessed
self.readPC = False
# Whether the whole PC needs to be written after parts of it were
# changed
self.setPC = False
# Whether this instruction manipulates the whole PC or parts of it.
# Mixing the two is a bad idea and flagged as an error.
self.pcPart = None
for op_desc in self.items:
if op_desc.isPCPart():
self.readPC = True
if op_desc.is_dest:
self.setPC = True
if op_desc.isPCState():
if self.pcPart is not None:
if self.pcPart and not op_desc.isPCPart() or \
not self.pcPart and op_desc.isPCPart():
error("Mixed whole and partial PC state operands.")
self.pcPart = op_desc.isPCPart()
if op_desc.isMem():
if self.memOperand:
error("Code block has more than one memory operand.")
self.memOperand = op_desc
# Regular expression object to match C++ strings
stringRE = re.compile(r'"([^"\\]|\\.)*"')
# Regular expression object to match C++ comments
# (used in findOperands())
commentRE = re.compile(r'(^)?[^\S\n]*/(?:\*(.*?)\*/[^\S\n]*|/[^\n]*)($)?',
re.DOTALL | re.MULTILINE)
# Regular expression object to match assignment statements
# (used in findOperands())
assignRE = re.compile(r'\s*=(?!=)', re.MULTILINE)
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
# Assume all instruction flags are of the form 'IsFoo'
instFlagRE = re.compile(r'Is.*')
# OpClass constants end in 'Op' except No_OpClass
opClassRE = re.compile(r'.*Op|No_OpClass')
class InstObjParams(object):
def __init__(self, parser, mnem, class_name, base_class = '',
snippets = {}, opt_args = []):
self.mnemonic = mnem
self.class_name = class_name
self.base_class = base_class
if not isinstance(snippets, dict):
snippets = {'code' : snippets}
compositeCode = ' '.join(map(str, snippets.values()))
self.snippets = snippets
self.operands = OperandList(parser, compositeCode)
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.flags = self.operands.concatAttrLists('flags')
# Make a basic guess on the operand class (function unit type).
# These are good enough for most cases, and can be overridden
# later otherwise.
if 'IsStore' in self.flags:
self.op_class = 'MemWriteOp'
elif 'IsLoad' in self.flags or 'IsPrefetch' in self.flags:
self.op_class = 'MemReadOp'
elif 'IsFloating' in self.flags:
self.op_class = 'FloatAddOp'
else:
self.op_class = 'IntAluOp'
# 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('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 = ''
##############
# Stack: a simple stack object. Used for both formats (formatStack)
# and default cases (defaultStack). Simply wraps a list to give more
# stack-like syntax and enable initialization with an argument list
# (as opposed to an argument that's a list).
class Stack(list):
def __init__(self, *items):
list.__init__(self, items)
def push(self, item):
self.append(item);
def top(self):
return self[-1]
#######################
#
# Output file template
#
file_template = '''
/*
* DO NOT EDIT THIS FILE!!!
*
* It was automatically generated from the ISA description in %(filename)s
*/
%(includes)s
%(global_output)s
namespace %(namespace)s {
%(namespace_output)s
} // namespace %(namespace)s
%(decode_function)s
'''
max_inst_regs_template = '''
/*
* DO NOT EDIT THIS FILE!!!
*
* It was automatically generated from the ISA description in %(filename)s
*/
namespace %(namespace)s {
const int MaxInstSrcRegs = %(MaxInstSrcRegs)d;
const int MaxInstDestRegs = %(MaxInstDestRegs)d;
} // namespace %(namespace)s
'''
class ISAParser(Grammar):
def __init__(self, output_dir, cpu_models):
super(ISAParser, self).__init__()
self.output_dir = output_dir
self.cpuModels = cpu_models
# variable to hold templates
self.templateMap = {}
# This dictionary maps format name strings to Format objects.
self.formatMap = {}
# The format stack.
self.formatStack = Stack(NoFormat())
# The default case stack.
self.defaultStack = Stack(None)
# Stack that tracks current file and line number. Each
# element is a tuple (filename, lineno) that records the
# *current* filename and the line number in the *previous*
# file where it was included.
self.fileNameStack = Stack()
symbols = ('makeList', 're', 'string')
self.exportContext = dict([(s, eval(s)) for s in symbols])
self.maxInstSrcRegs = 0
self.maxInstDestRegs = 0
#####################################################################
#
# 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', 'DECODE', 'DECODER', 'DEFAULT', 'DEF', 'EXEC', 'FORMAT',
'HEADER', 'LET', 'NAMESPACE', 'OPERAND_TYPES', 'OPERANDS',
'OUTPUT', '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',
'LBRACKET', 'RBRACKET',
'LBRACE', 'RBRACE',
'LESS', 'GREATER', 'EQUALS',
'COMMA', 'SEMI', 'DOT', 'COLON', 'DBLCOLON',
'ASTERISK',
# C preprocessor directives
'CPPDIRECTIVE'
# The following are matched but never returned. commented out to
# suppress PLY warning
# newfile directive
# 'NEWFILE',
# endfile directive
# 'ENDFILE'
)
# Regular expressions for token matching
t_LPAREN = r'\('
t_RPAREN = r'\)'
t_LBRACKET = r'\['
t_RBRACKET = r'\]'
t_LBRACE = r'\{'
t_RBRACE = r'\}'
t_LESS = r'\<'
t_GREATER = r'\>'
t_EQUALS = r'='
t_COMMA = r','
t_SEMI = r';'
t_DOT = 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(self, t):
r'[A-Za-z_]\w*'
t.type = self.reserved_map.get(t.value, 'ID')
return t
# Integer literal
def t_INTLIT(self, t):
r'-?(0x[\da-fA-F]+)|\d+'
try:
t.value = int(t.value,0)
except ValueError:
error(t, '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(self, t):
r"(?m)'([^'])+'"
# strip off quotes
t.value = t.value[1:-1]
t.lexer.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(self, t):
r"(?m)\{\{([^\}]|}(?!\}))+\}\}"
# strip off {{ & }}
t.value = t.value[2:-2]
t.lexer.lineno += t.value.count('\n')
return t
def t_CPPDIRECTIVE(self, t):
r'^\#[^\#].*\n'
t.lexer.lineno += t.value.count('\n')
return t
def t_NEWFILE(self, t):
r'^\#\#newfile\s+"[^"]*"'
self.fileNameStack.push((t.value[11:-1], t.lexer.lineno))
t.lexer.lineno = 0
def t_ENDFILE(self, t):
r'^\#\#endfile'
(old_filename, t.lexer.lineno) = self.fileNameStack.pop()
#
# The functions t_NEWLINE, t_ignore, and t_error are
# special for the lex module.
#
# Newlines
def t_NEWLINE(self, t):
r'\n+'
t.lexer.lineno += t.value.count('\n')
# Comments
def t_comment(self, t):
r'//.*'
# Completely ignored characters
t_ignore = ' \t\x0c'
# Error handler
def t_error(self, t):
error(t, "illegal character '%s'" % t.value[0])
t.skip(1)
#####################################################################
#
# 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]).
#####################################################################
# 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(self, t):
'specification : opt_defs_and_outputs name_decl opt_defs_and_outputs decode_block'
global_code = t[1]
isa_name = t[2]
namespace = isa_name + "Inst"
# wrap the decode block as a function definition
t[4].wrap_decode_block('''
StaticInstPtr
%(isa_name)s::decodeInst(%(isa_name)s::ExtMachInst machInst)
{
using namespace %(namespace)s;
''' % vars(), '}')
# both the latter output blocks and the decode block are in
# the namespace
namespace_code = t[3] + t[4]
# pass it all back to the caller of yacc.parse()
t[0] = (isa_name, namespace, global_code, namespace_code)
# ISA name declaration looks like "namespace <foo>;"
def p_name_decl(self, t):
'name_decl : NAMESPACE ID SEMI'
t[0] = t[2]
# 'opt_defs_and_outputs' is a possibly empty sequence of
# def and/or output statements.
def p_opt_defs_and_outputs_0(self, t):
'opt_defs_and_outputs : empty'
t[0] = GenCode(self)
def p_opt_defs_and_outputs_1(self, t):
'opt_defs_and_outputs : defs_and_outputs'
t[0] = t[1]
def p_defs_and_outputs_0(self, t):
'defs_and_outputs : def_or_output'
t[0] = t[1]
def p_defs_and_outputs_1(self, t):
'defs_and_outputs : defs_and_outputs def_or_output'
t[0] = t[1] + t[2]
# The list of possible definition/output statements.
def p_def_or_output(self, t):
'''def_or_output : def_format
| def_bitfield
| def_bitfield_struct
| def_template
| def_operand_types
| def_operands
| output_header
| output_decoder
| output_exec
| global_let'''
t[0] = t[1]
# Output blocks 'output <foo> {{...}}' (C++ code blocks) are copied
# directly to the appropriate output section.
# Massage output block by substituting in template definitions and
# bit operators. We handle '%'s embedded in the string that don't
# indicate template substitutions (or CPU-specific symbols, which
# get handled in GenCode) by doubling them first so that the
# format operation will reduce them back to single '%'s.
def process_output(self, s):
s = self.protectNonSubstPercents(s)
# protects cpu-specific symbols too
s = self.protectCpuSymbols(s)
return substBitOps(s % self.templateMap)
def p_output_header(self, t):
'output_header : OUTPUT HEADER CODELIT SEMI'
t[0] = GenCode(self, header_output = self.process_output(t[3]))
def p_output_decoder(self, t):
'output_decoder : OUTPUT DECODER CODELIT SEMI'
t[0] = GenCode(self, decoder_output = self.process_output(t[3]))
def p_output_exec(self, t):
'output_exec : OUTPUT EXEC CODELIT SEMI'
t[0] = GenCode(self, exec_output = self.process_output(t[3]))
# global let blocks 'let {{...}}' (Python code blocks) are
# executed directly when seen. Note that these execute in a
# special variable context 'exportContext' to prevent the code
# from polluting this script's namespace.
def p_global_let(self, t):
'global_let : LET CODELIT SEMI'
self.updateExportContext()
self.exportContext["header_output"] = ''
self.exportContext["decoder_output"] = ''
self.exportContext["exec_output"] = ''
self.exportContext["decode_block"] = ''
try:
exec fixPythonIndentation(t[2]) in self.exportContext
except Exception, exc:
if debug:
raise
error(t, 'error: %s in global let block "%s".' % (exc, t[2]))
t[0] = GenCode(self,
header_output=self.exportContext["header_output"],
decoder_output=self.exportContext["decoder_output"],
exec_output=self.exportContext["exec_output"],
decode_block=self.exportContext["decode_block"])
# Define the mapping from operand type extensions to C++ types and
# bit widths (stored in operandTypeMap).
def p_def_operand_types(self, t):
'def_operand_types : DEF OPERAND_TYPES CODELIT SEMI'
try:
self.operandTypeMap = eval('{' + t[3] + '}')
except Exception, exc:
if debug:
raise
error(t,
'error: %s in def operand_types block "%s".' % (exc, t[3]))
t[0] = GenCode(self) # contributes nothing to the output C++ file
# Define the mapping from operand names to operand classes and
# other traits. Stored in operandNameMap.
def p_def_operands(self, t):
'def_operands : DEF OPERANDS CODELIT SEMI'
if not hasattr(self, 'operandTypeMap'):
error(t, 'error: operand types must be defined before operands')
try:
user_dict = eval('{' + t[3] + '}', self.exportContext)
except Exception, exc:
if debug:
raise
error(t, 'error: %s in def operands block "%s".' % (exc, t[3]))
self.buildOperandNameMap(user_dict, t.lexer.lineno)
t[0] = GenCode(self) # 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(self, 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)
hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr)
t[0] = GenCode(self, header_output=hash_define)
# alternate form for single bit: 'def [signed] bitfield <ID> [<bit>]'
def p_def_bitfield_1(self, 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)
hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr)
t[0] = GenCode(self, header_output=hash_define)
# alternate form for structure member: 'def bitfield <ID> <ID>'
def p_def_bitfield_struct(self, t):
'def_bitfield_struct : DEF opt_signed BITFIELD ID id_with_dot SEMI'
if (t[2] != ''):
error(t, 'error: structure bitfields are always unsigned.')
expr = 'machInst.%s' % t[5]
hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr)
t[0] = GenCode(self, header_output=hash_define)
def p_id_with_dot_0(self, t):
'id_with_dot : ID'
t[0] = t[1]
def p_id_with_dot_1(self, t):
'id_with_dot : ID DOT id_with_dot'
t[0] = t[1] + t[2] + t[3]
def p_opt_signed_0(self, t):
'opt_signed : SIGNED'
t[0] = t[1]
def p_opt_signed_1(self, t):
'opt_signed : empty'
t[0] = ''
def p_def_template(self, t):
'def_template : DEF TEMPLATE ID CODELIT SEMI'
self.templateMap[t[3]] = Template(self, t[4])
t[0] = GenCode(self)
# An instruction format definition looks like
# "def format <fmt>(<params>) {{...}};"
def p_def_format(self, t):
'def_format : DEF FORMAT ID LPAREN param_list RPAREN CODELIT SEMI'
(id, params, code) = (t[3], t[5], t[7])
self.defFormat(id, params, code, t.lexer.lineno)
t[0] = GenCode(self)
# The formal parameter list for an instruction format is a
# possibly empty list of comma-separated parameters. Positional
# (standard, non-keyword) parameters must come first, followed by
# keyword parameters, followed by a '*foo' parameter that gets
# excess positional arguments (as in Python). Each of these three
# parameter categories is optional.
#
# Note that we do not support the '**foo' parameter for collecting
# otherwise undefined keyword args. Otherwise the parameter list
# is (I believe) identical to what is supported in Python.
#
# The param list generates a tuple, where the first element is a
# list of the positional params and the second element is a dict
# containing the keyword params.
def p_param_list_0(self, t):
'param_list : positional_param_list COMMA nonpositional_param_list'
t[0] = t[1] + t[3]
def p_param_list_1(self, t):
'''param_list : positional_param_list
| nonpositional_param_list'''
t[0] = t[1]
def p_positional_param_list_0(self, t):
'positional_param_list : empty'
t[0] = []
def p_positional_param_list_1(self, t):
'positional_param_list : ID'
t[0] = [t[1]]
def p_positional_param_list_2(self, t):
'positional_param_list : positional_param_list COMMA ID'
t[0] = t[1] + [t[3]]
def p_nonpositional_param_list_0(self, t):
'nonpositional_param_list : keyword_param_list COMMA excess_args_param'
t[0] = t[1] + t[3]
def p_nonpositional_param_list_1(self, t):
'''nonpositional_param_list : keyword_param_list
| excess_args_param'''
t[0] = t[1]
def p_keyword_param_list_0(self, t):
'keyword_param_list : keyword_param'
t[0] = [t[1]]
def p_keyword_param_list_1(self, t):
'keyword_param_list : keyword_param_list COMMA keyword_param'
t[0] = t[1] + [t[3]]
def p_keyword_param(self, t):
'keyword_param : ID EQUALS expr'
t[0] = t[1] + ' = ' + t[3].__repr__()
def p_excess_args_param(self, t):
'excess_args_param : ASTERISK ID'
# Just concatenate them: '*ID'. Wrap in list to be consistent
# with positional_param_list and keyword_param_list.
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(self, t):
'decode_block : DECODE ID opt_default LBRACE decode_stmt_list RBRACE'
default_defaults = self.defaultStack.pop()
codeObj = t[5]
# use the "default defaults" only if there was no explicit
# default statement in decode_stmt_list
if not codeObj.has_decode_default:
codeObj += default_defaults
codeObj.wrap_decode_block('switch (%s) {\n' % t[2], '}\n')
t[0] = codeObj
# 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(self, t):
'opt_default : empty'
# no default specified: reuse the one currently at the top of
# the stack
self.defaultStack.push(self.defaultStack.top())
# no meaningful value returned
t[0] = None
def p_opt_default_1(self, t):
'opt_default : DEFAULT inst'
# push the new default
codeObj = t[2]
codeObj.wrap_decode_block('\ndefault:\n', 'break;\n')
self.defaultStack.push(codeObj)
# no meaningful value returned
t[0] = None
def p_decode_stmt_list_0(self, t):
'decode_stmt_list : decode_stmt'
t[0] = t[1]
def p_decode_stmt_list_1(self, t):
'decode_stmt_list : decode_stmt decode_stmt_list'
if (t[1].has_decode_default and t[2].has_decode_default):
error(t, 'Two default cases in decode block')
t[0] = t[1] + t[2]
#
# 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 all of the output
# code 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(self, t):
'decode_stmt : CPPDIRECTIVE'
t[0] = GenCode(self, t[1], t[1], t[1], t[1])
# 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(self, 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.
self.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(self, t):
'push_format_id : ID'
try:
self.formatStack.push(self.formatMap[t[1]])
t[0] = ('', '// format %s' % t[1])
except KeyError:
error(t, '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(self, t):
'decode_stmt : case_label COLON decode_block'
label = t[1]
codeObj = t[3]
# just wrap the decoding code from the block as a case in the
# outer switch statement.
codeObj.wrap_decode_block('\n%s:\n' % label)
codeObj.has_decode_default = (label == 'default')
t[0] = codeObj
# Instruction definition (finally!).
def p_decode_stmt_inst(self, t):
'decode_stmt : case_label COLON inst SEMI'
label = t[1]
codeObj = t[3]
codeObj.wrap_decode_block('\n%s:' % label, 'break;\n')
codeObj.has_decode_default = (label == 'default')
t[0] = codeObj
# The case label is either a list of one or more constants or
# 'default'
def p_case_label_0(self, t):
'case_label : intlit_list'
def make_case(intlit):
if intlit >= 2**32:
return 'case ULL(%#x)' % intlit
else:
return 'case %#x' % intlit
t[0] = ': '.join(map(make_case, t[1]))
def p_case_label_1(self, t):
'case_label : DEFAULT'
t[0] = 'default'
#
# 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(self, t):
'intlit_list : INTLIT'
t[0] = [t[1]]
def p_intlit_list_1(self, 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(self, t):
'inst : ID LPAREN arg_list RPAREN'
# Pass the ID and arg list to the current format class to deal with.
currentFormat = self.formatStack.top()
codeObj = currentFormat.defineInst(self, t[1], t[3], t.lexer.lineno)
args = ','.join(map(str, t[3]))
args = re.sub('(?m)^', '//', args)
args = re.sub('^//', '', args)
comment = '\n// %s::%s(%s)\n' % (currentFormat.id, t[1], args)
codeObj.prepend_all(comment)
t[0] = codeObj
# Define an instruction using an explicitly specified format:
# "<fmt>::<mnemonic>(<args>)"
def p_inst_1(self, t):
'inst : ID DBLCOLON ID LPAREN arg_list RPAREN'
try:
format = self.formatMap[t[1]]
except KeyError:
error(t, 'instruction format "%s" not defined.' % t[1])
codeObj = format.defineInst(self, t[3], t[5], t.lexer.lineno)
comment = '\n// %s::%s(%s)\n' % (t[1], t[3], t[5])
codeObj.prepend_all(comment)
t[0] = codeObj
# The arg list generates a tuple, where the first element is a
# list of the positional args and the second element is a dict
# containing the keyword args.
def p_arg_list_0(self, t):
'arg_list : positional_arg_list COMMA keyword_arg_list'
t[0] = ( t[1], t[3] )
def p_arg_list_1(self, t):
'arg_list : positional_arg_list'
t[0] = ( t[1], {} )
def p_arg_list_2(self, t):
'arg_list : keyword_arg_list'
t[0] = ( [], t[1] )
def p_positional_arg_list_0(self, t):
'positional_arg_list : empty'
t[0] = []
def p_positional_arg_list_1(self, t):
'positional_arg_list : expr'
t[0] = [t[1]]
def p_positional_arg_list_2(self, t):
'positional_arg_list : positional_arg_list COMMA expr'
t[0] = t[1] + [t[3]]
def p_keyword_arg_list_0(self, t):
'keyword_arg_list : keyword_arg'
t[0] = t[1]
def p_keyword_arg_list_1(self, t):
'keyword_arg_list : keyword_arg_list COMMA keyword_arg'
t[0] = t[1]
t[0].update(t[3])
def p_keyword_arg(self, t):
'keyword_arg : ID EQUALS expr'
t[0] = { t[1] : t[3] }
#
# Basic expressions. These constitute the argument values of
# "function calls" (i.e. instruction definitions in the decode
# block) and default values for formal parameters of format
# functions.
#
# Right now, these are either strings, integers, or (recursively)
# lists of exprs (using Python square-bracket list syntax). Note
# that bare identifiers are trated as string constants here (since
# there isn't really a variable namespace to refer to).
#
def p_expr_0(self, t):
'''expr : ID
| INTLIT
| STRLIT
| CODELIT'''
t[0] = t[1]
def p_expr_1(self, t):
'''expr : LBRACKET list_expr RBRACKET'''
t[0] = t[2]
def p_list_expr_0(self, t):
'list_expr : expr'
t[0] = [t[1]]
def p_list_expr_1(self, t):
'list_expr : list_expr COMMA expr'
t[0] = t[1] + [t[3]]
def p_list_expr_2(self, t):
'list_expr : empty'
t[0] = []
#
# Empty production... use in other rules for readability.
#
def p_empty(self, 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(self, t):
if t:
error(t, "syntax error at '%s'" % t.value)
else:
error("unknown syntax error")
# END OF GRAMMAR RULES
def updateExportContext(self):
# create a continuation that allows us to grab the current parser
def wrapInstObjParams(*args):
return InstObjParams(self, *args)
self.exportContext['InstObjParams'] = wrapInstObjParams
self.exportContext.update(self.templateMap)
def defFormat(self, id, params, code, lineno):
'''Define a new format'''
# make sure we haven't already defined this one
if id in self.formatMap:
error(lineno, 'format %s redefined.' % id)
# create new object and store in global map
self.formatMap[id] = Format(id, params, code)
def expandCpuSymbolsToDict(self, template):
'''Expand template with CPU-specific references into a
dictionary with an entry for each CPU model name. The entry
key is the model name and the corresponding value is the
template with the CPU-specific refs substituted for that
model.'''
# Protect '%'s that don't go with CPU-specific terms
t = re.sub(r'%(?!\(CPU_)', '%%', template)
result = {}
for cpu in self.cpuModels:
result[cpu.name] = t % cpu.strings
return result
def expandCpuSymbolsToString(self, template):
'''*If* the template has CPU-specific references, return a
single string containing a copy of the template for each CPU
model with the corresponding values substituted in. If the
template has no CPU-specific references, it is returned
unmodified.'''
if template.find('%(CPU_') != -1:
return reduce(lambda x,y: x+y,
self.expandCpuSymbolsToDict(template).values())
else:
return template
def protectCpuSymbols(self, template):
'''Protect CPU-specific references by doubling the
corresponding '%'s (in preparation for substituting a different
set of references into the template).'''
return re.sub(r'%(?=\(CPU_)', '%%', template)
def protectNonSubstPercents(self, s):
'''Protect any non-dict-substitution '%'s in a format string
(i.e. those not followed by '(')'''
return re.sub(r'%(?!\()', '%%', s)
def buildOperandNameMap(self, user_dict, lineno):
operand_name = {}
for op_name, val in user_dict.iteritems():
base_cls_name, dflt_ext, reg_spec, flags, sort_pri = val[:5]
if len(val) > 5:
read_code = val[5]
else:
read_code = None
if len(val) > 6:
write_code = val[6]
else:
write_code = None
if len(val) > 7:
error(lineno,
'error: too many attributes for operand "%s"' %
base_cls_name)
# 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')
flags = ( [], [], [] )
elif isinstance(flags, str):
# a single flag: assumed to be unconditional
flags = ( [ flags ], [], [] )
elif isinstance(flags, list):
# a list of flags: also assumed to be unconditional
flags = ( flags, [], [] )
elif isinstance(flags, tuple):
# 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
flags = (makeList(uncond_flags),
makeList(src_flags), makeList(dest_flags))
# Accumulate attributes of new operand class in tmp_dict
tmp_dict = {}
attrList = ['reg_spec', 'flags', 'sort_pri',
'read_code', 'write_code']
if dflt_ext:
dflt_ctype = self.operandTypeMap[dflt_ext]
attrList.extend(['dflt_ctype', 'dflt_ext'])
for attr in attrList:
tmp_dict[attr] = eval(attr)
tmp_dict['base_name'] = op_name
# New class name will be e.g. "IntReg_Ra"
cls_name = base_cls_name + '_' + op_name
# Evaluate string arg to get class object. Note that the
# actual base class for "IntReg" is "IntRegOperand", i.e. we
# have to append "Operand".
try:
base_cls = eval(base_cls_name + 'Operand')
except NameError:
error(lineno,
'error: unknown operand base class "%s"' % base_cls_name)
# The following statement creates a new class called
# <cls_name> as a subclass of <base_cls> with the attributes
# in tmp_dict, just as if we evaluated a class declaration.
operand_name[op_name] = type(cls_name, (base_cls,), tmp_dict)
self.operandNameMap = operand_name
# Define operand variables.
operands = user_dict.keys()
extensions = self.operandTypeMap.keys()
operandsREString = r'''
(?<!\w) # neg. lookbehind assertion: prevent partial matches
((%s)(?:_(%s))?) # match: operand with optional '_' then suffix
(?!\w) # neg. lookahead assertion: prevent partial matches
''' % (string.join(operands, '|'), string.join(extensions, '|'))
self.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)_(%s)(?!\w)' \
% (string.join(operands, '|'), string.join(extensions, '|'))
self.operandsWithExtRE = \
re.compile(operandsWithExtREString, re.MULTILINE)
def substMungedOpNames(self, code):
'''Munge operand names in code string to make legal C++
variable names. This means getting rid of the type extension
if any. Will match base_name attribute of Operand object.)'''
return self.operandsWithExtRE.sub(r'\1', code)
def mungeSnippet(self, s):
'''Fix up code snippets for final substitution in templates.'''
if isinstance(s, str):
return self.substMungedOpNames(substBitOps(s))
else:
return s
def update_if_needed(self, file, contents):
'''Update the output file only if the new contents are
different from the current contents. Minimizes the files that
need to be rebuilt after minor changes.'''
file = os.path.join(self.output_dir, file)
update = False
if os.access(file, os.R_OK):
f = open(file, 'r')
old_contents = f.read()
f.close()
if contents != old_contents:
os.remove(file) # in case it's write-protected
update = True
else:
print 'File', file, 'is unchanged'
else:
update = True
if update:
f = open(file, 'w')
f.write(contents)
f.close()
# This regular expression matches '##include' directives
includeRE = re.compile(r'^\s*##include\s+"(?P<filename>[^"]*)".*$',
re.MULTILINE)
def replace_include(self, matchobj, dirname):
"""Function to replace a matched '##include' directive with the
contents of the specified file (with nested ##includes
replaced recursively). 'matchobj' is an re match object
(from a match of includeRE) and 'dirname' is the directory
relative to which the file path should be resolved."""
fname = matchobj.group('filename')
full_fname = os.path.normpath(os.path.join(dirname, fname))
contents = '##newfile "%s"\n%s\n##endfile\n' % \
(full_fname, self.read_and_flatten(full_fname))
return contents
def read_and_flatten(self, filename):
"""Read a file and recursively flatten nested '##include' files."""
current_dir = os.path.dirname(filename)
try:
contents = open(filename).read()
except IOError:
error('Error including file "%s"' % filename)
self.fileNameStack.push((filename, 0))
# Find any includes and include them
def replace(matchobj):
return self.replace_include(matchobj, current_dir)
contents = self.includeRE.sub(replace, contents)
self.fileNameStack.pop()
return contents
def _parse_isa_desc(self, isa_desc_file):
'''Read in and parse the ISA description.'''
# Read file and (recursively) all included files into a string.
# PLY requires that the input be in a single string so we have to
# do this up front.
isa_desc = self.read_and_flatten(isa_desc_file)
# Initialize filename stack with outer file.
self.fileNameStack.push((isa_desc_file, 0))
# Parse it.
(isa_name, namespace, global_code, namespace_code) = \
self.parse_string(isa_desc)
# grab the last three path components of isa_desc_file to put in
# the output
filename = '/'.join(isa_desc_file.split('/')[-3:])
# generate decoder.hh
includes = '#include "base/bitfield.hh" // for bitfield support'
global_output = global_code.header_output
namespace_output = namespace_code.header_output
decode_function = ''
self.update_if_needed('decoder.hh', file_template % vars())
# generate decoder.cc
includes = '#include "decoder.hh"'
global_output = global_code.decoder_output
namespace_output = namespace_code.decoder_output
# namespace_output += namespace_code.decode_block
decode_function = namespace_code.decode_block
self.update_if_needed('decoder.cc', file_template % vars())
# generate per-cpu exec files
for cpu in self.cpuModels:
includes = '#include "decoder.hh"\n'
includes += cpu.includes
global_output = global_code.exec_output[cpu.name]
namespace_output = namespace_code.exec_output[cpu.name]
decode_function = ''
self.update_if_needed(cpu.filename, file_template % vars())
# The variable names here are hacky, but this will creat local
# variables which will be referenced in vars() which have the
# value of the globals.
MaxInstSrcRegs = self.maxInstSrcRegs
MaxInstDestRegs = self.maxInstDestRegs
# max_inst_regs.hh
self.update_if_needed('max_inst_regs.hh',
max_inst_regs_template % vars())
def parse_isa_desc(self, *args, **kwargs):
try:
self._parse_isa_desc(*args, **kwargs)
except ISAParserError, e:
e.exit(self.fileNameStack)
# Called as script: get args from command line.
# Args are: <path to cpu_models.py> <isa desc file> <output dir> <cpu models>
if __name__ == '__main__':
execfile(sys.argv[1]) # read in CpuModel definitions
cpu_models = [CpuModel.dict[cpu] for cpu in sys.argv[4:]]
ISAParser(sys.argv[3], cpu_models).parse_isa_desc(sys.argv[2])