remove pseudo, moved to openpower-isa
[soc.git] / src / soc / decoder / pseudo / parser.py
diff --git a/src/soc/decoder/pseudo/parser.py b/src/soc/decoder/pseudo/parser.py
deleted file mode 100644 (file)
index 0e67196..0000000
+++ /dev/null
@@ -1,901 +0,0 @@
-# Based on GardenSnake - a parser generator demonstration program
-# GardenSnake was released into the Public Domain by Andrew Dalke.
-
-# Portions of this work are derived from Python's Grammar definition
-# and may be covered under the Python copyright and license
-#
-#          Andrew Dalke / Dalke Scientific Software, LLC
-#             30 August 2006 / Cape Town, South Africa
-
-# Modifications for inclusion in PLY distribution
-from pprint import pprint
-from ply import lex, yacc
-import astor
-from copy import deepcopy
-
-from openpower.decoder.power_decoder import create_pdecode
-from openpower.decoder.pseudo.lexer import IndentLexer
-from openpower.decoder.orderedset import OrderedSet
-
-# I use the Python AST
-#from compiler import ast
-import ast
-
-# Helper function
-
-
-def Assign(autoassign, assignname, left, right, iea_mode):
-    names = []
-    print("Assign", assignname, left, right)
-    if isinstance(left, ast.Name):
-        # Single assignment on left
-        # XXX when doing IntClass, which will have an "eq" function,
-        # this is how to access it
-        #   eq = ast.Attribute(left, "eq")   # get eq fn
-        #   return ast.Call(eq, [right], []) # now call left.eq(right)
-        return ast.Assign([ast.Name(left.id, ast.Store())], right)
-    elif isinstance(left, ast.Tuple):
-        # List of things - make sure they are Name nodes
-        names = []
-        for child in left.getChildren():
-            if not isinstance(child, ast.Name):
-                raise SyntaxError("that assignment not supported")
-            names.append(child.name)
-        ass_list = [ast.AssName(name, 'OP_ASSIGN') for name in names]
-        return ast.Assign([ast.AssTuple(ass_list)], right)
-    elif isinstance(left, ast.Subscript):
-        ls = left.slice
-        # XXX changing meaning of "undefined" to a function
-        #if (isinstance(ls, ast.Slice) and isinstance(right, ast.Name) and
-        #        right.id == 'undefined'):
-        #    # undefined needs to be copied the exact same slice
-        #    right = ast.Subscript(right, ls, ast.Load())
-        #    return ast.Assign([left], right)
-        res = ast.Assign([left], right)
-        if autoassign and isinstance(ls, ast.Slice):
-            # hack to create a variable pre-declared based on a slice.
-            # dividend[0:32] = (RA)[0:32] will create
-            #       dividend = [0] * 32
-            #       dividend[0:32] = (RA)[0:32]
-            # the declaration makes the slice-assignment "work"
-            lower, upper, step = ls.lower, ls.upper, ls.step
-            print("lower, upper, step", repr(lower), repr(upper), step)
-            if not isinstance(lower, ast.Constant) or \
-               not isinstance(upper, ast.Constant):
-                return res
-            qty = ast.Num(upper.value-lower.value)
-            keywords = [ast.keyword(arg='repeat', value=qty)]
-            l = [ast.Num(0)]
-            right = ast.Call(ast.Name("concat", ast.Load()), l, keywords)
-            declare = ast.Assign([ast.Name(assignname, ast.Store())], right)
-            return [declare, res]
-        return res
-        # XXX HMMM probably not needed...
-        ls = left.slice
-        if isinstance(ls, ast.Slice):
-            lower, upper, step = ls.lower, ls.upper, ls.step
-            print("slice assign", lower, upper, step)
-            if step is None:
-                ls = (lower, upper, None)
-            else:
-                ls = (lower, upper, step)
-            ls = ast.Tuple(ls)
-        return ast.Call(ast.Name("selectassign", ast.Load()),
-                        [left.value, ls, right], [])
-    else:
-        print("Assign fail")
-        raise SyntaxError("Can't do that yet")
-
-
-# I implemented INDENT / DEDENT generation as a post-processing filter
-
-# The original lex token stream contains WS and NEWLINE characters.
-# WS will only occur before any other tokens on a line.
-
-# I have three filters.  One tags tokens by adding two attributes.
-# "must_indent" is True if the token must be indented from the
-# previous code.  The other is "at_line_start" which is True for WS
-# and the first non-WS/non-NEWLINE on a line.  It flags the check so
-# see if the new line has changed indication level.
-
-
-# No using Python's approach because Ply supports precedence
-
-# comparison: expr (comp_op expr)*
-# arith_expr: term (('+'|'-') term)*
-# term: factor (('*'|'/'|'%'|'//') factor)*
-# factor: ('+'|'-'|'~') factor | power
-# comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
-
-def make_le_compare(arg):
-    (left, right) = arg
-    return ast.Call(ast.Name("le", ast.Load()), (left, right), [])
-
-
-def make_ge_compare(arg):
-    (left, right) = arg
-    return ast.Call(ast.Name("ge", ast.Load()), (left, right), [])
-
-
-def make_lt_compare(arg):
-    (left, right) = arg
-    return ast.Call(ast.Name("lt", ast.Load()), (left, right), [])
-
-
-def make_gt_compare(arg):
-    (left, right) = arg
-    return ast.Call(ast.Name("gt", ast.Load()), (left, right), [])
-
-
-def make_eq_compare(arg):
-    (left, right) = arg
-    return ast.Call(ast.Name("eq", ast.Load()), (left, right), [])
-
-
-def make_ne_compare(arg):
-    (left, right) = arg
-    return ast.Call(ast.Name("ne", ast.Load()), (left, right), [])
-
-
-binary_ops = {
-    "^": ast.BitXor(),
-    "&": ast.BitAnd(),
-    "|": ast.BitOr(),
-    "+": ast.Add(),
-    "-": ast.Sub(),
-    "*": ast.Mult(),
-    "/": ast.FloorDiv(),
-    "%": ast.Mod(),
-    "<=": make_le_compare,
-    ">=": make_ge_compare,
-    "<": make_lt_compare,
-    ">": make_gt_compare,
-    "=": make_eq_compare,
-    "!=": make_ne_compare,
-}
-unary_ops = {
-    "+": ast.UAdd(),
-    "-": ast.USub(),
-    "¬": ast.Invert(),
-}
-
-
-def check_concat(node):  # checks if the comparison is already a concat
-    print("check concat", node)
-    if not isinstance(node, ast.Call):
-        return [node]
-    print("func", node.func.id)
-    if node.func.id != 'concat':
-        return [node]
-    if node.keywords:  # a repeated list-constant, don't optimise
-        return [node]
-    return node.args
-
-
-# identify SelectableInt pattern [something] * N
-# must return concat(something, repeat=N)
-def identify_sint_mul_pattern(p):
-    if p[2] != '*':  # multiply
-        return False
-    if not isinstance(p[3], ast.Constant):  # rhs = Num
-        return False
-    if not isinstance(p[1], ast.List):  # lhs is a list
-        return False
-    l = p[1].elts
-    if len(l) != 1:  # lhs is a list of length 1
-        return False
-    return True  # yippee!
-
-
-def apply_trailer(atom, trailer):
-    if trailer[0] == "TLIST":
-        # assume depth of one
-        atom = apply_trailer(atom, trailer[1])
-        trailer = trailer[2]
-    if trailer[0] == "CALL":
-        #p[0] = ast.Expr(ast.Call(p[1], p[2][1], []))
-        return ast.Call(atom, trailer[1], [])
-        # if p[1].id == 'print':
-        #    p[0] = ast.Printnl(ast.Tuple(p[2][1]), None, None)
-        # else:
-        #    p[0] = ast.CallFunc(p[1], p[2][1], None, None)
-    else:
-        print("subscript atom", trailer[1])
-        #raise AssertionError("not implemented %s" % p[2][0])
-        subs = trailer[1]
-        if len(subs) == 1:
-            idx = subs[0]
-        else:
-            idx = ast.Slice(subs[0], subs[1], None)
-        # if isinstance(atom, ast.Name) and atom.id == 'CR':
-            # atom.id = 'CR' # bad hack
-            #print ("apply_trailer Subscript", atom.id, idx)
-        return ast.Subscript(atom, idx, ast.Load())
-
-##########   Parser (tokens -> AST) ######
-
-# also part of Ply
-#import yacc
-
-# https://www.mathcs.emory.edu/~valerie/courses/fall10/155/resources/op_precedence.html
-# python operator precedence
-# Highest precedence at top, lowest at bottom.
-# Operators in the same box evaluate left to right.
-#
-# Operator Description
-# ()                                                     Parentheses (grouping)
-# f(args...)                                             Function call
-# x[index:index]                                         Slicing
-# x[index]                                               Subscription
-# x.attribute                                            Attribute reference
-# **                                                     Exponentiation
-# ~x                                                     Bitwise not
-# +x, -x                                                 Positive, negative
-# *, /, %                                                mul, div, remainder
-# +, -                                                   Addition, subtraction
-# <<, >>                                                 Bitwise shifts
-# &                                                      Bitwise AND
-# ^                                                      Bitwise XOR
-# |                                                      Bitwise OR
-# in, not in, is, is not, <, <=,  >,  >=, <>, !=, ==     comp, membership, ident
-# not x                                                  Boolean NOT
-# and                                                    Boolean AND
-# or                                                     Boolean OR
-# lambda                                                 Lambda expression
-
-
-class PowerParser:
-
-    precedence = (
-        ("left", "EQ", "NE", "GT", "LT", "LE", "GE", "LTU", "GTU"),
-        ("left", "BITOR"),
-        ("left", "BITXOR"),
-        ("left", "BITAND"),
-        ("left", "PLUS", "MINUS"),
-        ("left", "MULT", "DIV", "MOD"),
-        ("left", "INVERT"),
-    )
-
-    def __init__(self, form, include_carry_in_write=False):
-        self.include_ca_in_write = include_carry_in_write
-        self.gprs = {}
-        form = self.sd.sigforms[form]
-        print(form)
-        formkeys = form._asdict().keys()
-        self.declared_vars = set()
-        for rname in ['RA', 'RB', 'RC', 'RT', 'RS']:
-            self.gprs[rname] = None
-            self.declared_vars.add(rname)
-        self.available_op_fields = set()
-        for k in formkeys:
-            if k not in self.gprs:
-                if k == 'SPR':  # sigh, lower-case to not conflict
-                    k = k.lower()
-                self.available_op_fields.add(k)
-        self.op_fields = OrderedSet()
-        self.read_regs = OrderedSet()
-        self.uninit_regs = OrderedSet()
-        self.write_regs = OrderedSet()
-        self.special_regs = OrderedSet()  # see p_atom_name
-
-    # The grammar comments come from Python's Grammar/Grammar file
-
-    # NB: compound_stmt in single_input is followed by extra NEWLINE!
-    # file_input: (NEWLINE | stmt)* ENDMARKER
-
-    def p_file_input_end(self, p):
-        """file_input_end : file_input ENDMARKER"""
-        print("end", p[1])
-        p[0] = p[1]
-
-    def p_file_input(self, p):
-        """file_input : file_input NEWLINE
-                      | file_input stmt
-                      | NEWLINE
-                      | stmt"""
-        if isinstance(p[len(p)-1], str):
-            if len(p) == 3:
-                p[0] = p[1]
-            else:
-                p[0] = []  # p == 2 --> only a blank line
-        else:
-            if len(p) == 3:
-                p[0] = p[1] + p[2]
-            else:
-                p[0] = p[1]
-
-    # funcdef: [decorators] 'def' NAME parameters ':' suite
-    # ignoring decorators
-
-    def p_funcdef(self, p):
-        "funcdef : DEF NAME parameters COLON suite"
-        p[0] = ast.FunctionDef(p[2], p[3], p[5], ())
-
-    # parameters: '(' [varargslist] ')'
-    def p_parameters(self, p):
-        """parameters : LPAR RPAR
-                      | LPAR varargslist RPAR"""
-        if len(p) == 3:
-            args = []
-        else:
-            args = p[2]
-        p[0] = ast.arguments(args=args, vararg=None, kwarg=None, defaults=[])
-
-    # varargslist: (fpdef ['=' test] ',')* ('*' NAME [',' '**' NAME] |
-    # '**' NAME) |
-    # highly simplified
-
-    def p_varargslist(self, p):
-        """varargslist : varargslist COMMA NAME
-                       | NAME"""
-        if len(p) == 4:
-            p[0] = p[1] + p[3]
-        else:
-            p[0] = [p[1]]
-
-    # stmt: simple_stmt | compound_stmt
-    def p_stmt_simple(self, p):
-        """stmt : simple_stmt"""
-        # simple_stmt is a list
-        p[0] = p[1]
-
-    def p_stmt_compound(self, p):
-        """stmt : compound_stmt"""
-        p[0] = [p[1]]
-
-    # simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
-    def p_simple_stmt(self, p):
-        """simple_stmt : small_stmts NEWLINE
-                       | small_stmts SEMICOLON NEWLINE"""
-        p[0] = p[1]
-
-    def p_small_stmts(self, p):
-        """small_stmts : small_stmts SEMICOLON small_stmt
-                       | small_stmt"""
-        if len(p) == 4:
-            p[0] = p[1] + [p[3]]
-        elif isinstance(p[1], list):
-            p[0] = p[1]
-        else:
-            p[0] = [p[1]]
-
-    # small_stmt: expr_stmt | print_stmt  | del_stmt | pass_stmt | flow_stmt |
-    #    import_stmt | global_stmt | exec_stmt | assert_stmt
-    def p_small_stmt(self, p):
-        """small_stmt : flow_stmt
-                      | break_stmt
-                      | expr_stmt"""
-        if isinstance(p[1], ast.Call):
-            p[0] = ast.Expr(p[1])
-        elif isinstance(p[1], ast.Name) and p[1].id == 'TRAP':
-            # TRAP needs to actually be a function
-            name = ast.Name("self", ast.Load())
-            name = ast.Attribute(name, "TRAP", ast.Load())
-            p[0] = ast.Call(name, [], [])
-        else:
-            p[0] = p[1]
-
-    # expr_stmt: testlist (augassign (yield_expr|testlist) |
-    #                      ('=' (yield_expr|testlist))*)
-    # augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
-    #             '<<=' | '>>=' | '**=' | '//=')
-    def p_expr_stmt(self, p):
-        """expr_stmt : testlist ASSIGNEA testlist
-                     | testlist ASSIGN testlist
-                     | testlist """
-        print("expr_stmt", p)
-        if len(p) == 2:
-            # a list of expressions
-            #p[0] = ast.Discard(p[1])
-            p[0] = p[1]
-        else:
-            iea_mode = p[2] == '<-iea'
-            name = None
-            autoassign = False
-            if isinstance(p[1], ast.Name):
-                name = p[1].id
-            elif isinstance(p[1], ast.Subscript):
-                if isinstance(p[1].value, ast.Name):
-                    name = p[1].value.id
-                    if name in self.gprs:
-                        # add to list of uninitialised
-                        self.uninit_regs.add(name)
-                    autoassign = (name not in self.declared_vars and
-                                  name not in self.special_regs)
-            elif isinstance(p[1], ast.Call) and p[1].func.id in ['GPR', 'SPR']:
-                print(astor.dump_tree(p[1]))
-                # replace GPR(x) with GPR[x]
-                idx = p[1].args[0]
-                p[1] = ast.Subscript(p[1].func, idx, ast.Load())
-            elif isinstance(p[1], ast.Call) and p[1].func.id == 'MEM':
-                print("mem assign")
-                print(astor.dump_tree(p[1]))
-                p[1].func.id = "memassign"  # change function name to set
-                p[1].args.append(p[3])
-                p[0] = p[1]
-                print("mem rewrite")
-                print(astor.dump_tree(p[0]))
-                return
-            else:
-                print("help, help")
-                print(astor.dump_tree(p[1]))
-            print("expr assign", name, p[1])
-            if name and name in self.gprs:
-                self.write_regs.add(name)  # add to list of regs to write
-            p[0] = Assign(autoassign, name, p[1], p[3], iea_mode)
-            if name:
-                self.declared_vars.add(name)
-
-    def p_flow_stmt(self, p):
-        "flow_stmt : return_stmt"
-        p[0] = p[1]
-
-    # return_stmt: 'return' [testlist]
-    def p_return_stmt(self, p):
-        "return_stmt : RETURN testlist"
-        p[0] = ast.Return(p[2])
-
-    def p_compound_stmt(self, p):
-        """compound_stmt : if_stmt
-                         | while_stmt
-                         | switch_stmt
-                         | for_stmt
-                         | funcdef
-        """
-        p[0] = p[1]
-
-    def p_break_stmt(self, p):
-        """break_stmt : BREAK
-        """
-        p[0] = ast.Break()
-
-    def p_for_stmt(self, p):
-        """for_stmt : FOR atom EQ test TO test COLON suite
-                    | DO atom EQ test TO test COLON suite
-        """
-        start = p[4]
-        end = p[6]
-        if start.value > end.value:  # start greater than end, must go -ve
-            # auto-subtract-one (sigh) due to python range
-            end = ast.BinOp(p[6], ast.Add(), ast.Constant(-1))
-            arange = [start, end, ast.Constant(-1)]
-        else:
-            # auto-add-one (sigh) due to python range
-            end = ast.BinOp(p[6], ast.Add(), ast.Constant(1))
-            arange = [start, end]
-        it = ast.Call(ast.Name("range", ast.Load()), arange, [])
-        p[0] = ast.For(p[2], it, p[8], [])
-
-    def p_while_stmt(self, p):
-        """while_stmt : DO WHILE test COLON suite ELSE COLON suite
-                      | DO WHILE test COLON suite
-        """
-        if len(p) == 6:
-            p[0] = ast.While(p[3], p[5], [])
-        else:
-            p[0] = ast.While(p[3], p[5], p[8])
-
-    def p_switch_smt(self, p):
-        """switch_stmt : SWITCH LPAR atom RPAR COLON NEWLINE INDENT switches DEDENT
-        """
-        switchon = p[3]
-        print("switch stmt")
-        print(astor.dump_tree(p[1]))
-
-        cases = []
-        current_cases = []  # for deferral
-        for (case, suite) in p[8]:
-            print("for", case, suite)
-            if suite is None:
-                for c in case:
-                    current_cases.append(ast.Num(c))
-                continue
-            if case == 'default':  # last
-                break
-            for c in case:
-                current_cases.append(ast.Num(c))
-            print("cases", current_cases)
-            compare = ast.Compare(switchon, [ast.In()],
-                                  [ast.List(current_cases, ast.Load())])
-            current_cases = []
-            cases.append((compare, suite))
-
-        print("ended", case, current_cases)
-        if case == 'default':
-            if current_cases:
-                compare = ast.Compare(switchon, [ast.In()],
-                                      [ast.List(current_cases, ast.Load())])
-                cases.append((compare, suite))
-            cases.append((None, suite))
-
-        cases.reverse()
-        res = []
-        for compare, suite in cases:
-            print("after rev", compare, suite)
-            if compare is None:
-                assert len(res) == 0, "last case should be default"
-                res = suite
-            else:
-                if not isinstance(res, list):
-                    res = [res]
-                res = ast.If(compare, suite, res)
-        p[0] = res
-
-    def p_switches(self, p):
-        """switches : switch_list switch_default
-                    | switch_default
-        """
-        if len(p) == 3:
-            p[0] = p[1] + [p[2]]
-        else:
-            p[0] = [p[1]]
-
-    def p_switch_list(self, p):
-        """switch_list : switch_case switch_list
-                       | switch_case
-        """
-        if len(p) == 3:
-            p[0] = [p[1]] + p[2]
-        else:
-            p[0] = [p[1]]
-
-    def p_switch_case(self, p):
-        """switch_case : CASE LPAR atomlist RPAR COLON suite
-        """
-        # XXX bad hack
-        if isinstance(p[6][0], ast.Name) and p[6][0].id == 'fallthrough':
-            p[6] = None
-        p[0] = (p[3], p[6])
-
-    def p_switch_default(self, p):
-        """switch_default : DEFAULT COLON suite
-        """
-        p[0] = ('default', p[3])
-
-    def p_atomlist(self, p):
-        """atomlist : atom COMMA atomlist
-                    | atom
-        """
-        assert isinstance(p[1], ast.Constant), "case must be numbers"
-        if len(p) == 4:
-            p[0] = [p[1].value] + p[3]
-        else:
-            p[0] = [p[1].value]
-
-    def p_if_stmt(self, p):
-        """if_stmt : IF test COLON suite ELSE COLON if_stmt
-                   | IF test COLON suite ELSE COLON suite
-                   | IF test COLON suite
-        """
-        if len(p) == 8 and isinstance(p[7], ast.If):
-            p[0] = ast.If(p[2], p[4], [p[7]])
-        elif len(p) == 5:
-            p[0] = ast.If(p[2], p[4], [])
-        else:
-            p[0] = ast.If(p[2], p[4], p[7])
-
-    def p_suite(self, p):
-        """suite : simple_stmt
-                 | NEWLINE INDENT stmts DEDENT"""
-        if len(p) == 2:
-            p[0] = p[1]
-        else:
-            p[0] = p[3]
-
-    def p_stmts(self, p):
-        """stmts : stmts stmt
-                 | stmt"""
-        if len(p) == 3:
-            p[0] = p[1] + p[2]
-        else:
-            p[0] = p[1]
-
-    def p_comparison(self, p):
-        """comparison : comparison PLUS comparison
-                      | comparison MINUS comparison
-                      | comparison MULT comparison
-                      | comparison DIV comparison
-                      | comparison MOD comparison
-                      | comparison EQ comparison
-                      | comparison NE comparison
-                      | comparison LE comparison
-                      | comparison GE comparison
-                      | comparison LTU comparison
-                      | comparison GTU comparison
-                      | comparison LT comparison
-                      | comparison GT comparison
-                      | comparison BITOR comparison
-                      | comparison BITXOR comparison
-                      | comparison BITAND comparison
-                      | PLUS comparison
-                      | comparison MINUS
-                      | INVERT comparison
-                      | comparison APPEND comparison
-                      | power"""
-        if len(p) == 4:
-            print(list(p))
-            if p[2] == '<u':
-                p[0] = ast.Call(ast.Name("ltu", ast.Load()), (p[1], p[3]), [])
-            elif p[2] == '>u':
-                p[0] = ast.Call(ast.Name("gtu", ast.Load()), (p[1], p[3]), [])
-            elif p[2] == '||':
-                l = check_concat(p[1]) + check_concat(p[3])
-                p[0] = ast.Call(ast.Name("concat", ast.Load()), l, [])
-            elif p[2] in ['/', '%']:
-                # bad hack: if % or / used anywhere other than div/mod ops,
-                # do % or /.  however if the argument names are "dividend"
-                # we must call the special trunc_divs and trunc_rems functions
-                l, r = p[1], p[3]
-                # actual call will be "dividend / divisor" - just check
-                # LHS name
-                # XXX DISABLE BAD HACK (False)
-                if False and isinstance(l, ast.Name) and l.id == 'dividend':
-                    if p[2] == '/':
-                        fn = 'trunc_divs'
-                    else:
-                        fn = 'trunc_rems'
-                    # return "function trunc_xxx(l, r)"
-                    p[0] = ast.Call(ast.Name(fn, ast.Load()), (l, r), [])
-                else:
-                    # return "l {binop} r"
-                    p[0] = ast.BinOp(p[1], binary_ops[p[2]], p[3])
-            elif p[2] in ['<', '>', '=', '<=', '>=', '!=']:
-                p[0] = binary_ops[p[2]]((p[1], p[3]))
-            elif identify_sint_mul_pattern(p):
-                keywords = [ast.keyword(arg='repeat', value=p[3])]
-                l = p[1].elts
-                p[0] = ast.Call(ast.Name("concat", ast.Load()), l, keywords)
-            else:
-                p[0] = ast.BinOp(p[1], binary_ops[p[2]], p[3])
-        elif len(p) == 3:
-            if isinstance(p[2], str) and p[2] == '-':
-                p[0] = ast.UnaryOp(unary_ops[p[2]], p[1])
-            else:
-                p[0] = ast.UnaryOp(unary_ops[p[1]], p[2])
-        else:
-            p[0] = p[1]
-
-    # power: atom trailer* ['**' factor]
-    # trailers enables function calls (and subscripts).
-    # so this is 'trailerlist'
-    def p_power(self, p):
-        """power : atom
-                 | atom trailerlist"""
-        if len(p) == 2:
-            print("power dump atom notrailer")
-            print(astor.dump_tree(p[1]))
-            p[0] = p[1]
-        else:
-            print("power dump atom")
-            print(astor.dump_tree(p[1]))
-            print("power dump trailerlist")
-            print(astor.dump_tree(p[2]))
-            p[0] = apply_trailer(p[1], p[2])
-            if isinstance(p[1], ast.Name):
-                name = p[1].id
-                if name in ['RA', 'RS', 'RB', 'RC', 'RT']:
-                    self.read_regs.add(name)
-
-    def p_atom_name(self, p):
-        """atom : NAME"""
-        name = p[1]
-        if name in self.available_op_fields:
-            self.op_fields.add(name)
-        if name == 'overflow':
-            self.write_regs.add(name)
-        if self.include_ca_in_write:
-            if name in ['CA', 'CA32']:
-                self.write_regs.add(name)
-        if name in ['CR', 'LR', 'CTR', 'TAR', 'FPSCR', 'MSR', 'SVSTATE']:
-            self.special_regs.add(name)
-            self.write_regs.add(name)  # and add to list to write
-        p[0] = ast.Name(id=name, ctx=ast.Load())
-
-    def p_atom_number(self, p):
-        """atom : BINARY
-                | NUMBER
-                | HEX
-                | STRING"""
-        p[0] = ast.Constant(p[1])
-
-    # '[' [listmaker] ']' |
-
-    def p_atom_listmaker(self, p):
-        """atom : LBRACK listmaker RBRACK"""
-        p[0] = p[2]
-
-    def p_listmaker(self, p):
-        """listmaker : test COMMA listmaker
-                     | test
-        """
-        if len(p) == 2:
-            p[0] = ast.List([p[1]], ast.Load())
-        else:
-            p[0] = ast.List([p[1]] + p[3].nodes, ast.Load())
-
-    def p_atom_tuple(self, p):
-        """atom : LPAR testlist RPAR"""
-        print("tuple", p[2])
-        print("astor dump")
-        print(astor.dump_tree(p[2]))
-
-        if isinstance(p[2], ast.Name):
-            name = p[2].id
-            print("tuple name", name)
-            if name in self.gprs:
-                self.read_regs.add(name)  # add to list of regs to read
-                #p[0] = ast.Subscript(ast.Name("GPR", ast.Load()), ast.Str(p[2].id))
-                # return
-            p[0] = p[2]
-        elif isinstance(p[2], ast.BinOp):
-            if isinstance(p[2].left, ast.Name) and \
-               isinstance(p[2].right, ast.Constant) and \
-                    p[2].right.value == 0 and \
-                    p[2].left.id in self.gprs:
-                rid = p[2].left.id
-                self.read_regs.add(rid)  # add to list of regs to read
-                # create special call to GPR.getz
-                gprz = ast.Name("GPR", ast.Load())
-                # get testzero function
-                gprz = ast.Attribute(gprz, "getz", ast.Load())
-                # *sigh* see class GPR.  we need index itself not reg value
-                ridx = ast.Name("_%s" % rid, ast.Load())
-                p[0] = ast.Call(gprz, [ridx], [])
-                print("tree", astor.dump_tree(p[0]))
-            else:
-                p[0] = p[2]
-        else:
-            p[0] = p[2]
-
-    def p_trailerlist(self, p):
-        """trailerlist : trailer trailerlist
-                       | trailer
-        """
-        if len(p) == 2:
-            p[0] = p[1]
-        else:
-            p[0] = ("TLIST", p[1], p[2])
-
-    # trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
-    def p_trailer(self, p):
-        """trailer : trailer_arglist
-                   | trailer_subscript
-        """
-        p[0] = p[1]
-
-    def p_trailer_arglist(self, p):
-        "trailer_arglist : LPAR arglist RPAR"
-        p[0] = ("CALL", p[2])
-
-    def p_trailer_subscript(self, p):
-        "trailer_subscript : LBRACK subscript RBRACK"
-        p[0] = ("SUBS", p[2])
-
-    # subscript: '.' '.' '.' | test | [test] ':' [test]
-
-    def p_subscript(self, p):
-        """subscript : test COLON test
-                     | test
-        """
-        if len(p) == 4:
-            # add one to end
-            if isinstance(p[3], ast.Constant):
-                end = ast.Constant(p[3].value+1)
-            else:
-                end = ast.BinOp(p[3], ast.Add(), ast.Constant(1))
-            p[0] = [p[1], end]
-        else:
-            p[0] = [p[1]]
-
-    # testlist: test (',' test)* [',']
-    # Contains shift/reduce error
-
-    def p_testlist(self, p):
-        """testlist : testlist_multi COMMA
-                    | testlist_multi """
-        if len(p) == 2:
-            p[0] = p[1]
-        else:
-            # May need to promote singleton to tuple
-            if isinstance(p[1], list):
-                p[0] = p[1]
-            else:
-                p[0] = [p[1]]
-        # Convert into a tuple?
-        if isinstance(p[0], list):
-            p[0] = ast.Tuple(p[0])
-
-    def p_testlist_multi(self, p):
-        """testlist_multi : testlist_multi COMMA test
-                          | test"""
-        if len(p) == 2:
-            # singleton
-            p[0] = p[1]
-        else:
-            if isinstance(p[1], list):
-                p[0] = p[1] + [p[3]]
-            else:
-                # singleton -> tuple
-                p[0] = [p[1], p[3]]
-
-    # test: or_test ['if' or_test 'else' test] | lambdef
-    #  as I don't support 'and', 'or', and 'not' this works down to 'comparison'
-
-    def p_test(self, p):
-        "test : comparison"
-        p[0] = p[1]
-
-    # arglist: (argument ',')* (argument [',']| '*' test [',' '**' test]
-    # | '**' test)
-    # XXX INCOMPLETE: this doesn't allow the trailing comma
-
-    def p_arglist(self, p):
-        """arglist : arglist COMMA argument
-                   | argument"""
-        if len(p) == 4:
-            p[0] = p[1] + [p[3]]
-        else:
-            p[0] = [p[1]]
-
-    # argument: test [gen_for] | test '=' test  # Really [keyword '='] test
-    def p_argument(self, p):
-        "argument : test"
-        p[0] = p[1]
-
-    def p_error(self, p):
-        # print "Error!", repr(p)
-        raise SyntaxError(p)
-
-
-class GardenSnakeParser(PowerParser):
-    def __init__(self, lexer=None, debug=False, form=None, incl_carry=False):
-        self.sd = create_pdecode()
-        PowerParser.__init__(self, form, incl_carry)
-        self.debug = debug
-        if lexer is None:
-            lexer = IndentLexer(debug=0)
-        self.lexer = lexer
-        self.tokens = lexer.tokens
-        self.parser = yacc.yacc(module=self, start="file_input_end",
-                                debug=debug, write_tables=False)
-
-    def parse(self, code):
-        # self.lexer.input(code)
-        result = self.parser.parse(code, lexer=self.lexer, debug=self.debug)
-        return ast.Module(result)
-
-
-###### Code generation ######
-
-#from compiler import misc, syntax, pycodegen
-
-_CACHED_PARSERS = {}
-_CACHE_PARSERS = True
-
-
-class GardenSnakeCompiler(object):
-    def __init__(self, debug=False, form=None, incl_carry=False):
-        if _CACHE_PARSERS:
-            try:
-                parser = _CACHED_PARSERS[debug, form, incl_carry]
-            except KeyError:
-                parser = GardenSnakeParser(debug=debug, form=form,
-                                           incl_carry=incl_carry)
-                _CACHED_PARSERS[debug, form, incl_carry] = parser
-
-            self.parser = deepcopy(parser)
-        else:
-            self.parser = GardenSnakeParser(debug=debug, form=form,
-                                            incl_carry=incl_carry)
-
-    def compile(self, code, mode="exec", filename="<string>"):
-        tree = self.parser.parse(code)
-        print("snake")
-        pprint(tree)
-        return tree
-        #misc.set_filename(filename, tree)
-        return compile(tree, mode="exec", filename="<string>")
-        # syntax.check(tree)
-        gen = pycodegen.ModuleCodeGenerator(tree)
-        code = gen.getCode()
-        return code