# Copyright (c) 2014, 2016, 2018-2019, 2022 ARM Limited # All rights reserved # # The license below extends only to copyright in the software and shall # not be construed as granting a license to any other intellectual # property including but not limited to intellectual property relating # to a hardware implementation of the functionality of the software # licensed hereunder. You may use the software subject to the license # terms below provided that you ensure that this notice is replicated # unmodified and in its entirety in all distributions of the software, # modified or unmodified, in source code or in binary form. # # Copyright (c) 2003-2005 The Regents of The University of Michigan # Copyright (c) 2013,2015 Advanced Micro Devices, Inc. # 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 re import sys import traceback # get type names from types import * from grammar import Grammar from .operand_list import * from .operand_types import * from .util import * debug = False #################### # 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"(?( &std::remove_pointer_t::srcRegIdxArr), reinterpret_cast( &std::remove_pointer_t::destRegIdxArr)); """ pcstate_decl = ( f"{self.parser.namespace}::PCState __parserAutoPCState;\n" ) myDict["op_decl"] = operands.concatAttrStrings("op_decl") if operands.readPC or operands.setPC: myDict["op_decl"] += pcstate_decl 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"] += pcstate_decl if operands.setPC: myDict["op_dest_decl"] += pcstate_decl myDict["op_rd"] = operands.concatAttrStrings("op_rd") if operands.readPC: myDict["op_rd"] = ( "set(__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. def __str__(self): return 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 = ", ".join(params) f = f"""def defInst(_code, _context, {param_list}): my_locals = vars().copy() exec(_code, _context, my_locals) return my_locals """ c = compile(f, label + " wrapper", "exec") exec(c, globals()) 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 as exc: if debug: raise error(lineno, f'error defining "{name}": {exc}.') for k in list(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, f'instruction definition "{name}" with no active format!' ) ############### # 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 the string of code for the # 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. def __init__( self, parser, header_output="", decoder_output="", exec_output="", decode_block="", has_decode_default=False, ): self.parser = parser self.header_output = header_output self.decoder_output = decoder_output self.exec_output = exec_output self.decode_block = decode_block self.has_decode_default = has_decode_default # Write these code chunks out to the filesystem. They will be properly # interwoven by the write_top_level_files(). def emit(self): if self.header_output: self.parser.get_file("header").write(self.header_output) if self.decoder_output: self.parser.get_file("decoder").write(self.decoder_output) if self.exec_output: self.parser.get_file("exec").write(self.exec_output) if self.decode_block: self.parser.get_file("decode_block").write(self.decode_block) # Override '+' operator: generate a new GenCode object that # concatenates all the individual strings in the operands. def __add__(self, other): return GenCode( self.parser, self.header_output + other.header_output, self.decoder_output + other.decoder_output, self.exec_output + other.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 self.exec_output = pre + self.exec_output # 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"(?") bitOpExprRE = re.compile(r"\)<\s*(\w+)\s*:\s*(\w+)\s*>") def substBitOps(code): # first convert single-bit selectors to two-index form # i.e., --> code = bitOp1ArgRE.sub(r"<\1:\1>", code) # simple case: selector applied to ID (name) # i.e., foo --> 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] 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 + (post + pre).join(flag_list) + 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(list(map(str, snippets.values()))) self.snippets = snippets self.operands = OperandList(parser, compositeCode) self.srcRegIdxPadding = 0 self.destRegIdxPadding = 0 # The header of the constructor declares the variables to be used # in the body of the constructor. header = "" self.constructor = header + self.operands.concatAttrStrings( "constructor" ) self.flags = self.operands.concatAttrLists("flags") self.op_class = None # 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 ) # Make a basic guess on the operand class if not set. # These are good enough for most cases. if not self.op_class: if "IsStore" in self.flags: # The order matters here: 'IsFloating' and 'IsInteger' are # usually set in FP instructions because of the base # register if "IsFloating" in self.flags: self.op_class = "FloatMemWriteOp" else: self.op_class = "MemWriteOp" elif "IsLoad" in self.flags or "IsPrefetch" in self.flags: # The order matters here: 'IsFloating' and 'IsInteger' are # usually set in FP instructions because of the base # register if "IsFloating" in self.flags: self.op_class = "FloatMemReadOp" else: self.op_class = "MemReadOp" elif "IsFloating" in self.flags: self.op_class = "FloatAddOp" elif "IsVector" in self.flags: self.op_class = "SimdAddOp" elif "IsMatrix" in self.flags: self.op_class = "MatrixOp" else: self.op_class = "IntAluOp" # 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 'IsVector' is set, add call to the Vector 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 padSrcRegIdx(self, padding): self.srcRegIdxPadding = padding def padDestRegIdx(self, padding): self.destRegIdxPadding = padding ####################### # # ISA Parser # parses ISA DSL and emits C++ headers and source # class ISAParser(Grammar): def __init__(self, output_dir, decoder_name="Decoder"): super().__init__() self.lex_kwargs["reflags"] = int(re.MULTILINE) self.output_dir = output_dir self.filename = None # for output file watermarking/scaremongering # variable to hold templates self.templateMap = {} # variable to hold operands self.operandNameMap = {} # Regular expressions for working with operands self._operandsRE = None self._operandsWithExtRE = None # This dictionary maps format name strings to Format objects. self.formatMap = {} # Track open files and, if applicable, how many chunks it has been # split into so far. self.files = {} self.splits = {} # isa_name / namespace identifier from namespace declaration. # before the namespace declaration, None. self.isa_name = None self.namespace = None # decoder_name is class name for cpu decoder. self.decoder_name = decoder_name # 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") self.exportContext = dict([(s, eval(s)) for s in symbols]) self.exportContext.update( { "overrideInOperand": overrideInOperand, "IntRegOp": IntRegOperandDesc, "FloatRegOp": FloatRegOperandDesc, "CCRegOp": CCRegOperandDesc, "VecElemOp": VecElemOperandDesc, "VecRegOp": VecRegOperandDesc, "VecPredRegOp": VecPredRegOperandDesc, "MatRegOp": MatRegOperandDesc, "ControlRegOp": ControlRegOperandDesc, "MemOp": MemOperandDesc, "PCStateOp": PCStateOperandDesc, } ) self.maxMiscDestRegs = 0 def operandsRE(self): if not self._operandsRE: self.buildOperandREs() return self._operandsRE def operandsWithExtRE(self): if not self._operandsWithExtRE: self.buildOperandREs() return self._operandsWithExtRE def __getitem__(self, i): # Allow object (self) to be return getattr(self, i) # passed to %-substitutions # Change the file suffix of a base filename: # (e.g.) decoder.cc -> decoder-g.cc.inc for 'global' outputs def suffixize(self, s, sec): extn = re.compile("(\.[^\.]+)$") # isolate extension if self.namespace: return extn.sub(r"-ns\1.inc", s) # insert some text on either side else: return extn.sub(r"-g\1.inc", s) # Get the file object for emitting code into the specified section # (header, decoder, exec, decode_block). def get_file(self, section): if section == "decode_block": filename = "decode-method.cc.inc" else: if section == "header": file = "decoder.hh" else: file = f"{section}.cc" filename = self.suffixize(file, section) try: return self.files[filename] except KeyError: pass f = self.open(filename) self.files[filename] = f # The splittable files are the ones with many independent # per-instruction functions - the decoder's instruction constructors # and the instruction execution (execute()) methods. These both have # the suffix -ns.cc.inc, meaning they are within the namespace part # of the ISA, contain object-emitting C++ source, and are included # into other top-level files. These are the files that need special # #define's to allow parts of them to be compiled separately. Rather # than splitting the emissions into separate files, the monolithic # output of the ISA parser is maintained, but the value (or lack # thereof) of the __SPLIT definition during C preprocessing will # select the different chunks. If no 'split' directives are used, # the cpp emissions have no effect. if re.search("-ns.cc.inc$", filename): print("#if !defined(__SPLIT) || (__SPLIT == 1)", file=f) self.splits[f] = 1 # ensure requisite #include's elif filename == "decoder-g.hh.inc": print('#include "base/bitfield.hh"', file=f) return f # Weave together the parts of the different output sections by # #include'ing them into some very short top-level .cc/.hh files. # These small files make it much clearer how this tool works, since # you directly see the chunks emitted as files that are #include'd. def write_top_level_files(self): # decoder header - everything depends on this file = "decoder.hh" with self.open(file) as f: f.write( "#ifndef __ARCH_%(isa)s_GENERATED_DECODER_HH__\n" "#define __ARCH_%(isa)s_GENERATED_DECODER_HH__\n\n" % {"isa": self.isa_name.upper()} ) fn = "decoder-g.hh.inc" assert fn in self.files f.write(f'#include "{fn}"\n') fn = "decoder-ns.hh.inc" assert fn in self.files f.write("namespace gem5\n{\n") f.write( 'namespace %s {\n#include "%s"\n} // namespace %s\n' % (self.namespace, fn, self.namespace) ) f.write("} // namespace gem5") f.write( f"\n#endif // __ARCH_{self.isa_name.upper()}_GENERATED_DECODER_HH__\n" ) # decoder method - cannot be split file = "decoder.cc" with self.open(file) as f: fn = "base/compiler.hh" f.write(f'#include "{fn}"\n') fn = "decoder-g.cc.inc" assert fn in self.files f.write(f'#include "{fn}"\n') fn = "decoder.hh" f.write(f'#include "{fn}"\n') fn = "decode-method.cc.inc" # is guaranteed to have been written for parse to complete f.write(f'#include "{fn}"\n') extn = re.compile("(\.[^\.]+)$") # instruction constructors splits = self.splits[self.get_file("decoder")] file_ = "inst-constrs.cc" for i in range(1, splits + 1): if splits > 1: file = extn.sub(r"-%d\1" % i, file_) else: file = file_ with self.open(file) as f: fn = "decoder-g.cc.inc" assert fn in self.files f.write(f'#include "{fn}"\n') fn = "decoder.hh" f.write(f'#include "{fn}"\n') fn = "decoder-ns.cc.inc" assert fn in self.files print("namespace gem5\n{\n", file=f) print("namespace %s {" % self.namespace, file=f) if splits > 1: print("#define __SPLIT %u" % i, file=f) print(f'#include "{fn}"', file=f) print("} // namespace %s" % self.namespace, file=f) print("} // namespace gem5", file=f) # instruction execution splits = self.splits[self.get_file("exec")] for i in range(1, splits + 1): file = "generic_cpu_exec.cc" if splits > 1: file = extn.sub(r"_%d\1" % i, file) with self.open(file) as f: fn = "exec-g.cc.inc" assert fn in self.files f.write(f'#include "{fn}"\n') f.write('#include "cpu/exec_context.hh"\n') f.write('#include "decoder.hh"\n') fn = "exec-ns.cc.inc" assert fn in self.files print("namespace gem5\n{\n", file=f) print("namespace %s {" % self.namespace, file=f) if splits > 1: print("#define __SPLIT %u" % i, file=f) print(f'#include "{fn}"', file=f) print("} // namespace %s" % self.namespace, file=f) print("} // namespace gem5", file=f) scaremonger_template = """// DO NOT EDIT // This file was automatically generated from an ISA description: // %(filename)s """ ##################################################################### # # 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", "SPLIT", "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.lexer.lineno, f'Integer value "{t.value}" too large') 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"'([^'])+'" # 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"\{\{([^\}]|}(?!\}))+\}\}" # strip off {{ & }} t.value = t.value[2:-2] t.lexer.lineno += t.value.count("\n") return t def t_CPPDIRECTIVE(self, t): r"^\#[^\#][^\n]*\n" t.lexer.lineno += t.value.count("\n") return t def t_NEWFILE(self, t): r'^\#\#newfile\s+"[^"\n]*"\n' self.fileNameStack.push(t.lexer.lineno) t.lexer.lineno = LineTracker(t.value[11:-2]) def t_ENDFILE(self, t): r"^\#\#endfile\n" 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"//[^\n]*\n" # Completely ignored characters t_ignore = " \t\x0c" # Error handler def t_error(self, t): error(t.lexer.lineno, f"illegal character '{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 top_level_decode_block" for f in self.splits.keys(): f.write("\n#endif\n") for f in self.files.values(): # close ALL the files; f.close() # not doing so can cause compilation to fail self.write_top_level_files() t[0] = True # 'opt_defs_and_outputs' is a possibly empty sequence of def and/or # output statements. Its productions do the hard work of eventually # instantiating a GenCode, which are generally emitted (written to disk) # as soon as possible, except for the decode_block, which has to be # accumulated into one large function of nested switch/case blocks. def p_opt_defs_and_outputs_0(self, t): "opt_defs_and_outputs : empty" def p_opt_defs_and_outputs_1(self, t): "opt_defs_and_outputs : defs_and_outputs" def p_defs_and_outputs_0(self, t): "defs_and_outputs : def_or_output" def p_defs_and_outputs_1(self, t): "defs_and_outputs : defs_and_outputs def_or_output" # The list of possible definition/output statements. # They are all processed as they are seen. def p_def_or_output(self, t): """def_or_output : name_decl | def_format | def_bitfield | def_bitfield_struct | def_template | def_operand_types | def_operands | output | global_let | split""" # Utility function used by both invocations of splitting - explicit # 'split' keyword and split() function inside "let {{ }};" blocks. def split(self, sec, write=False): assert sec != "header" and "header cannot be split" f = self.get_file(sec) self.splits[f] += 1 s = "\n#endif\n#if __SPLIT == %u\n" % self.splits[f] if write: f.write(s) else: return s # split output file to reduce compilation time def p_split(self, t): "split : SPLIT output_type SEMI" assert self.isa_name and "'split' not allowed before namespace decl" self.split(t[2], True) def p_output_type(self, t): """output_type : DECODER | HEADER | EXEC""" t[0] = t[1] # ISA name declaration looks like "namespace ;" def p_name_decl(self, t): "name_decl : NAMESPACE ID SEMI" assert self.isa_name == None and "Only 1 namespace decl permitted" self.isa_name = t[2] self.namespace = t[2] + "Inst" # Output blocks 'output {{...}}' (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 by doubling them first so that the # format operation will reduce them back to single '%'s. def process_output(self, s): s = protectNonSubstPercents(s) return substBitOps(s % self.templateMap) def p_output(self, t): "output : OUTPUT output_type CODELIT SEMI" kwargs = {t[2] + "_output": self.process_output(t[3])} GenCode(self, **kwargs).emit() def make_split(self): def _split(sec): return self.split(sec) return _split # 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"] = "" self.exportContext["split"] = self.make_split() split_setup = """ def wrap(func): def split(sec): globals()[sec + '_output'] += func(sec) return split split = wrap(split) del wrap """ # This tricky setup (immediately above) allows us to just write # (e.g.) "split('exec')" in the Python code and the split #ifdef's # will automatically be added to the exec_output variable. The inner # Python execution environment doesn't know about the split points, # so we carefully inject and wrap a closure that can retrieve the # next split's #define from the parser and add it to the current # emission-in-progress. try: exec(split_setup + fixPythonIndentation(t[2]), self.exportContext) except Exception as exc: traceback.print_exc(file=sys.stdout) if debug: raise error(t.lineno(1), f"In global let block: {exc}") 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"], ).emit() # 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 as exc: if debug: raise error(t.lineno(1), f"In def operand_types: {exc}") # 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.lineno(1), "error: operand types must be defined before operands", ) try: user_dict = eval("{" + t[3] + "}", self.exportContext) except Exception as exc: if debug: raise error(t.lineno(1), f"In def operands: {exc}") self.buildOperandNameMap(user_dict, t.lexer.lineno) # A bitfield definition looks like: # 'def [signed] bitfield [:]' # 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 = f"#undef {t[4]}\n#define {t[4]}\t{expr}\n" GenCode(self, header_output=hash_define).emit() # alternate form for single bit: 'def [signed] bitfield []' 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 = f"#undef {t[4]}\n#define {t[4]}\t{expr}\n" GenCode(self, header_output=hash_define).emit() # alternate form for structure member: 'def bitfield ' def p_def_bitfield_struct(self, t): "def_bitfield_struct : DEF opt_signed BITFIELD ID id_with_dot SEMI" if t[2] != "": error( t.lineno(1), "error: structure bitfields are always unsigned." ) expr = f"machInst.{t[5]}" hash_define = f"#undef {t[4]}\n#define {t[4]}\t{expr}\n" GenCode(self, header_output=hash_define).emit() 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" if t[3] in self.templateMap: print(f"warning: template {t[3]} already defined") self.templateMap[t[3]] = Template(self, t[4]) # An instruction format definition looks like # "def format () {{...}};" 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) # 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 [, ]* [default ] { ... } # def p_top_level_decode_block(self, t): "top_level_decode_block : decode_block" codeObj = t[1] codeObj.wrap_decode_block( """ using namespace gem5; StaticInstPtr %(isa_name)s::%(decoder_name)s::decodeInst(%(isa_name)s::ExtMachInst machInst) { using namespace %(namespace)s; """ % self, "}", ) codeObj.emit() 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.lineno(1), "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 { ... }' # 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 { ... }' 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] = ("", f"// format {t[1]}") except KeyError: error(t.lineno(1), f'instruction format "{t[1]}" not defined.') # Nested decode block: if the value of the current field matches # the specified constant(s), do a nested decode on some other field. def p_decode_stmt_decode(self, t): "decode_stmt : case_list COLON decode_block" case_list = 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( f"\n{''.join(case_list)}\n", "GEM5_UNREACHABLE;\n" ) codeObj.has_decode_default = case_list == ["default:"] t[0] = codeObj # Instruction definition (finally!). def p_decode_stmt_inst(self, t): "decode_stmt : case_list COLON inst SEMI" case_list = t[1] codeObj = t[3] codeObj.wrap_decode_block(f"\n{''.join(case_list)}", "break;\n") codeObj.has_decode_default = case_list == ["default:"] t[0] = codeObj # The constant list for a decode case label must be non-empty, and must # either be the keyword 'default', or made up of one or more # comma-separated integer literals or strings which evaluate to # constants when compiled as C++. def p_case_list_0(self, t): "case_list : DEFAULT" t[0] = ["default:"] def prep_int_lit_case_label(self, lit): if lit >= 2**32: return "case %#xULL: " % lit else: return "case %#x: " % lit def prep_str_lit_case_label(self, lit): return f"case {lit}: " def p_case_list_1(self, t): "case_list : INTLIT" t[0] = [self.prep_int_lit_case_label(t[1])] def p_case_list_2(self, t): "case_list : STRLIT" t[0] = [self.prep_str_lit_case_label(t[1])] def p_case_list_3(self, t): "case_list : case_list COMMA INTLIT" t[0] = t[1] t[0].append(self.prep_int_lit_case_label(t[3])) def p_case_list_4(self, t): "case_list : case_list COMMA STRLIT" t[0] = t[1] t[0].append(self.prep_str_lit_case_label(t[3])) # Define an instruction using the current instruction format # (specified by an enclosing format block). # "()" 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(list(map(str, t[3]))) args = re.sub("(?m)^", "//", args) args = re.sub("^//", "", args) comment = f"\n// {currentFormat.id}::{t[1]}({args})\n" codeObj.prepend_all(comment) t[0] = codeObj # Define an instruction using an explicitly specified format: # "::()" def p_inst_1(self, t): "inst : ID DBLCOLON ID LPAREN arg_list RPAREN" try: format = self.formatMap[t[1]] except KeyError: error(t.lineno(1), f'instruction format "{t[1]}" not defined.') codeObj = format.defineInst(self, t[3], t[5], t.lexer.lineno) comment = f"\n// {t[1]}::{t[3]}({t[5]})\n" 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.lexer.lineno, f"syntax error at '{t.value}'") else: error("unknown syntax error") # END OF GRAMMAR RULES def updateExportContext(self): # Create a wrapper class that allows us to grab the current parser. class InstObjParamsWrapper(InstObjParams): def __init__(iop, *args, **kwargs): super().__init__(self, *args, **kwargs) self.exportContext["InstObjParams"] = InstObjParamsWrapper 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, f"format {id} redefined.") # create new object and store in global map self.formatMap[id] = Format(id, params, code) def buildOperandNameMap(self, user_dict, lineno): operand_name = {} for op_name, op_desc in user_dict.items(): assert isinstance(op_desc, OperandDesc) base_cls = op_desc.attrs["base_cls"] op_desc.setName(op_name) # New class name will be e.g. "IntRegOperand_Ra" cls_name = base_cls.__name__ + "_" + op_name # The following statement creates a new class called # as a subclass of with the attributes # in op_desc.attrs, just as if we evaluated a class declaration. operand_name[op_name] = type(cls_name, (base_cls,), op_desc.attrs) self.operandNameMap.update(operand_name) def buildOperandREs(self): # Define operand variables. operands = list(self.operandNameMap.keys()) # Add the elems defined in the vector operands and # build a map elem -> vector (used in OperandList) elem_to_vec = {} for op_name, op in self.operandNameMap.items(): if hasattr(op, "elems"): for elem in op.elems.keys(): operands.append(elem) elem_to_vec[elem] = op_name self.elemToVector = elem_to_vec extensions = self.operandTypeMap.keys() operandsREString = r""" (?[^"]*)".*$', re.MULTILINE ) def replace_include(self, matchobj, dirname): """Function to replace a matched '##include' directive with the contents of the specified file (with nested ##includes replaced recursively). 'matchobj' is an re match object (from a match of includeRE) and 'dirname' is the directory relative to which the file path should be resolved.""" fname = matchobj.group("filename") full_fname = os.path.normpath(os.path.join(dirname, fname)) contents = '##newfile "%s"\n%s\n##endfile\n' % ( full_fname, self.read_and_flatten(full_fname), ) return contents def read_and_flatten(self, filename): """Read a file and recursively flatten nested '##include' files.""" current_dir = os.path.dirname(filename) try: contents = open(filename).read() except IOError: error(f'Error including file "{filename}"') self.fileNameStack.push(LineTracker(filename)) # Find any includes and include them def replace(matchobj): return self.replace_include(matchobj, current_dir) contents = self.includeRE.sub(replace, contents) self.fileNameStack.pop() return contents AlreadyGenerated = {} def _parse_isa_desc(self, isa_desc_file): """Read in and parse the ISA description.""" # The build system can end up running the ISA parser twice: once to # finalize the build dependencies, and then to actually generate # the files it expects (in src/arch/$ARCH/generated). This code # doesn't do anything different either time, however; the SCons # invocations just expect different things. Since this code runs # within SCons, we can just remember that we've already run and # not perform a completely unnecessary run, since the ISA parser's # effect is idempotent. if isa_desc_file in ISAParser.AlreadyGenerated: return # grab the last three path components of isa_desc_file self.filename = "/".join(isa_desc_file.split("/")[-3:]) # 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 lineno tracker self.lex.lineno = LineTracker(isa_desc_file) # Parse. self.parse_string(isa_desc) ISAParser.AlreadyGenerated[isa_desc_file] = None def parse_isa_desc(self, *args, **kwargs): try: self._parse_isa_desc(*args, **kwargs) except ISAParserError as e: print(backtrace(self.fileNameStack)) print(f"At {e.lineno}:") print(e) sys.exit(1) # Called as script: get args from command line. # Args are: if __name__ == "__main__": ISAParser(sys.argv[2]).parse_isa_desc(sys.argv[1])