/pypy/jit/backend/llgraph/llimpl.py

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"""
The non-RPythonic part of the llgraph backend.
This contains all the code that is directly run
when executing on top of the llinterpreter.
"""

import weakref
from pypy.objspace.flow.model import Variable, Constant
from pypy.annotation import model as annmodel
from pypy.jit.metainterp.history import REF, INT, FLOAT
from pypy.jit.metainterp import history
from pypy.jit.codewriter import heaptracker
from pypy.rpython.lltypesystem import lltype, llmemory, rclass, rstr, rffi
from pypy.rpython.ootypesystem import ootype
from pypy.rpython.module.support import LLSupport, OOSupport
from pypy.rpython.llinterp import LLException
from pypy.rpython.extregistry import ExtRegistryEntry

from pypy.jit.metainterp import resoperation
from pypy.jit.metainterp.resoperation import rop
from pypy.jit.backend.llgraph import symbolic
from pypy.jit.codewriter import longlong

from pypy.rlib import libffi, clibffi
from pypy.rlib.objectmodel import ComputedIntSymbolic, we_are_translated
from pypy.rlib.rarithmetic import ovfcheck
from pypy.rlib.rarithmetic import r_longlong, r_ulonglong, r_uint
from pypy.rlib.rtimer import read_timestamp

import py
from pypy.tool.ansi_print import ansi_log
log = py.log.Producer('runner')
py.log.setconsumer('runner', ansi_log)

IS_32_BIT = r_ulonglong is not r_uint


def _from_opaque(opq):
    return opq._obj.externalobj

_TO_OPAQUE = {}

def _to_opaque(value):
    try:
        return value._the_opaque_pointer
    except AttributeError:
        op = lltype.opaqueptr(_TO_OPAQUE[value.__class__], 'opaque',
                              externalobj=value)
        value._the_opaque_pointer = op
        return op

def _normalize(value):
    if isinstance(value, lltype._ptr):
        value = lltype.top_container(value._obj)
    return value

def from_opaque_string(s):
    if isinstance(s, str):
        return s
    elif isinstance(s, ootype._string):
        return OOSupport.from_rstr(s)
    else:
        return LLSupport.from_rstr(s)

FLOAT_ARRAY_TP = lltype.Ptr(lltype.Array(lltype.Float, hints={"nolength": True}))
def maybe_uncast(TP, array):
    if array._TYPE.TO._hints.get("uncast_on_llgraph"):
        array = rffi.cast(TP, array)
    return array

# a list of argtypes of all operations - couldn't find any and it's
# very useful.  Note however that the table is half-broken here and
# there, in ways that are sometimes a bit hard to fix; that's why
# it is not "official".
TYPES = {
    'int_add'         : (('int', 'int'), 'int'),
    'int_sub'         : (('int', 'int'), 'int'),
    'int_mul'         : (('int', 'int'), 'int'),
    'int_floordiv'    : (('int', 'int'), 'int'),
    'int_mod'         : (('int', 'int'), 'int'),
    'int_and'         : (('int', 'int'), 'int'),
    'int_or'          : (('int', 'int'), 'int'),
    'int_xor'         : (('int', 'int'), 'int'),
    'int_lshift'      : (('int', 'int'), 'int'),
    'int_rshift'      : (('int', 'int'), 'int'),
    'int_lt'          : (('int', 'int'), 'bool'),
    'int_gt'          : (('int', 'int'), 'bool'),
    'int_ge'          : (('int', 'int'), 'bool'),
    'int_le'          : (('int', 'int'), 'bool'),
    'int_eq'          : (('int', 'int'), 'bool'),
    'int_ne'          : (('int', 'int'), 'bool'),
    'int_is_true'     : (('int',), 'bool'),
    'int_is_zero'     : (('int',), 'bool'),
    'int_neg'         : (('int',), 'int'),
    'int_invert'      : (('int',), 'int'),
    'int_add_ovf'     : (('int', 'int'), 'int'),
    'int_sub_ovf'     : (('int', 'int'), 'int'),
    'int_mul_ovf'     : (('int', 'int'), 'int'),
    'uint_add'        : (('int', 'int'), 'int'),
    'uint_sub'        : (('int', 'int'), 'int'),
    'uint_mul'        : (('int', 'int'), 'int'),
    'uint_lt'         : (('int', 'int'), 'bool'),
    'uint_le'         : (('int', 'int'), 'bool'),
    'uint_eq'         : (('int', 'int'), 'bool'),
    'uint_ne'         : (('int', 'int'), 'bool'),
    'uint_gt'         : (('int', 'int'), 'bool'),
    'uint_ge'         : (('int', 'int'), 'bool'),
    'uint_xor'        : (('int', 'int'), 'int'),
    'uint_rshift'     : (('int', 'int'), 'int'),
    'uint_floordiv'   : (('int', 'int'), 'int'),
    'float_add'       : (('float', 'float'), 'float'),
    'float_sub'       : (('float', 'float'), 'float'),
    'float_mul'       : (('float', 'float'), 'float'),
    'float_truediv'   : (('float', 'float'), 'float'),
    'float_lt'        : (('float', 'float'), 'bool'),
    'float_le'        : (('float', 'float'), 'bool'),
    'float_eq'        : (('float', 'float'), 'bool'),
    'float_ne'        : (('float', 'float'), 'bool'),
    'float_gt'        : (('float', 'float'), 'bool'),
    'float_ge'        : (('float', 'float'), 'bool'),
    'float_neg'       : (('float',), 'float'),
    'float_abs'       : (('float',), 'float'),
    'cast_float_to_int':(('float',), 'int'),
    'cast_int_to_float':(('int',), 'float'),
    'same_as'         : (('int',), 'int'),      # could also be ptr=>ptr
    'new_with_vtable' : (('ref',), 'ref'),
    'new'             : ((), 'ref'),
    'new_array'       : (('int',), 'ref'),
    'oois'            : (('ref', 'ref'), 'bool'),
    'ooisnot'         : (('ref', 'ref'), 'bool'),
    'instanceof'      : (('ref',), 'bool'),
    'subclassof'      : (('ref', 'ref'), 'bool'),
    'runtimenew'      : (('ref',), 'ref'),
    'setfield_gc'     : (('ref', 'intorptr'), None),
    'getfield_gc'     : (('ref',), 'intorptr'),
    'getfield_gc_pure': (('ref',), 'intorptr'),
    'setfield_raw'    : (('ref', 'intorptr'), None),
    'getfield_raw'    : (('ref',), 'intorptr'),
    'getfield_raw_pure': (('ref',), 'intorptr'),
    'setarrayitem_gc' : (('ref', 'int', 'intorptr'), None),
    'getarrayitem_gc' : (('ref', 'int'), 'intorptr'),
    'getarrayitem_gc_pure' : (('ref', 'int'), 'intorptr'),
    'setarrayitem_raw' : (('ref', 'int', 'intorptr'), None),
    'getarrayitem_raw' : (('ref', 'int'), 'intorptr'),
    'getarrayitem_raw_pure' : (('ref', 'int'), 'intorptr'),
    'arraylen_gc'     : (('ref',), 'int'),
    'call'            : (('ref', 'varargs'), 'intorptr'),
    'call_assembler'  : (('varargs',), 'intorptr'),
    'cond_call_gc_wb' : (('ptr', 'ptr'), None),
    'cond_call_gc_wb_array': (('ptr', 'int', 'ptr'), None),
    'oosend'          : (('varargs',), 'intorptr'),
    'oosend_pure'     : (('varargs',), 'intorptr'),
    'guard_true'      : (('bool',), None),
    'guard_false'     : (('bool',), None),
    'guard_value'     : (('int', 'int'), None),
    'guard_class'     : (('ref', 'ref'), None),
    'guard_no_exception'   : ((), None),
    'guard_exception'      : (('ref',), 'ref'),
    'guard_no_overflow'    : ((), None),
    'guard_overflow'       : ((), None),
    'guard_nonnull'        : (('ref',), None),
    'guard_isnull'        : (('ref',), None),
    'guard_nonnull_class' : (('ref', 'ref'), None),
    'newstr'          : (('int',), 'ref'),
    'strlen'          : (('ref',), 'int'),
    'strgetitem'      : (('ref', 'int'), 'int'),
    'strsetitem'      : (('ref', 'int', 'int'), None),
    'newunicode'      : (('int',), 'ref'),
    'unicodelen'      : (('ref',), 'int'),
    'unicodegetitem'  : (('ref', 'int'), 'int'),
    'unicodesetitem'  : (('ref', 'int', 'int'), 'int'),
    'cast_ptr_to_int' : (('ref',), 'int'),
    'cast_int_to_ptr' : (('int',), 'ref'),
    'debug_merge_point': (('ref', 'int', 'int'), None),
    'force_token'     : ((), 'int'),
    'call_may_force'  : (('int', 'varargs'), 'intorptr'),
    'guard_not_forced': ((), None),
}

# ____________________________________________________________

class CompiledLoop(object):
    has_been_freed = False
    invalid = False

    def __init__(self):
        self.inputargs = []
        self.operations = []

    def getargtypes(self):
        return [v.concretetype for v in self.inputargs]

    def __repr__(self):
        lines = []
        self.as_text(lines, 1)
        return 'CompiledLoop %s:\n%s' % (self.inputargs, '\n'.join(lines))

    def as_text(self, lines, indent):
        for op in self.operations:
            lines.append('\t'*indent + repr(op))

class Operation(object):
    result = None
    descr = None
    jump_target = None
    fail_args = None

    def __init__(self, opnum):
        self.opnum = opnum
        self.args = []

    def __repr__(self):
        if self.result is not None:
            sres = repr0(self.result) + ' = '
        else:
            sres = ''
        return '{%s%s(%s)}' % (sres, self.getopname(),
                               ', '.join(map(repr0, self.args)))

    def getopname(self):
        try:
            return resoperation.opname[self.opnum]
        except KeyError:
            return '<%d>' % self.opnum

    def is_guard(self):
        return rop._GUARD_FIRST <= self.opnum <= rop._GUARD_LAST

    def is_final(self):
        return rop._FINAL_FIRST <= self.opnum <= rop._FINAL_LAST

def repr0(x):
    if isinstance(x, list):
        return '[' + ', '.join(repr0(y) for y in x) + ']'
    elif isinstance(x, Constant):
        return '(' + repr0(x.value) + ')'
    elif isinstance(x, lltype._ptr):
        x = llmemory.cast_ptr_to_adr(x)
        if x.ptr:
            try:
                container = x.ptr._obj._normalizedcontainer()
                return '* %s' % (container._TYPE._short_name(),)
            except AttributeError:
                return repr(x)
        else:
            return 'NULL'
    else:
        return repr(x)

def repr_list(lst, types):
    res_l = []
    if types and types[-1] == 'varargs':
        types = types[:-1] + ('int',) * (len(lst) - len(types) + 1)
    assert len(types) == len(lst)
    for elem, tp in zip(lst, types):
        if isinstance(elem, Constant):
            res_l.append('(%s)' % repr1(elem, tp))
        else:
            res_l.append(repr1(elem, tp))
    return '[%s]' % (', '.join(res_l))

def repr1(x, tp):
    if tp == "intorptr":
        TYPE = lltype.typeOf(x)
        if isinstance(TYPE, lltype.Ptr) and TYPE.TO._gckind == 'gc':
            tp = "ref"
        else:
            tp = "int"
    if tp == 'int':
        return str(x)
    elif tp == 'void':
        return '---'
    elif tp == 'ref':
        if not x:
            return '(* None)'
        if isinstance(x, int):
            # XXX normalize?
            ptr = str(llmemory.cast_int_to_adr(x))
        elif isinstance(ootype.typeOf(x), ootype.OOType):
            return repr(x)
        else:
            if getattr(x, '_fake', None):
                return repr(x)
            if lltype.typeOf(x) == llmemory.GCREF:
                TP = lltype.Ptr(lltype.typeOf(x._obj.container))
                ptr = lltype.cast_opaque_ptr(TP, x)
            else:
                ptr = x
        try:
            container = ptr._obj._normalizedcontainer()
            return '(* %s)' % (container._TYPE._short_name(),)
        except AttributeError:
            return '(%r)' % (ptr,)
    elif tp == 'bool':
        assert x == 0 or x == 1
        return str(bool(x))
    #elif tp == 'fieldname':
    #    return str(symbolic.TokenToField[x...][1])
    elif tp == 'float':
        return str(x)
    else:
        raise NotImplementedError("tp = %s" % tp)

_variables = []

def compile_start():
    del _variables[:]
    return _to_opaque(CompiledLoop())

def mark_as_free(loop):
    loop = _from_opaque(loop)
    assert not loop.has_been_freed
    loop.has_been_freed = True

def compile_start_int_var(loop):
    return compile_start_ref_var(loop, lltype.Signed)

def compile_start_float_var(loop):
    return compile_start_ref_var(loop, longlong.FLOATSTORAGE)

def compile_start_ref_var(loop, TYPE):
    loop = _from_opaque(loop)
    assert not loop.operations
    v = Variable()
    v.concretetype = TYPE
    loop.inputargs.append(v)
    r = len(_variables)
    _variables.append(v)
    return r

def compile_started_vars(clt):
    if not hasattr(clt, '_debug_argtypes'):    # only when compiling the loop
        argtypes = [v.concretetype for v in _variables]
        try:
            clt._debug_argtypes = argtypes
        except AttributeError:    # when 'clt' is actually a translated
            pass                  # GcStruct

def compile_add(loop, opnum):
    loop = _from_opaque(loop)
    loop.operations.append(Operation(opnum))

def compile_add_descr(loop, ofs, type, arg_types, extrainfo, width):
    from pypy.jit.backend.llgraph.runner import Descr
    loop = _from_opaque(loop)
    op = loop.operations[-1]
    assert isinstance(type, str) and len(type) == 1
    op.descr = Descr(ofs, type, arg_types=arg_types, extrainfo=extrainfo, width=width)

def compile_add_descr_arg(loop, ofs, type, arg_types):
    from pypy.jit.backend.llgraph.runner import Descr
    loop = _from_opaque(loop)
    op = loop.operations[-1]
    assert isinstance(type, str) and len(type) == 1
    op.args.append(Descr(ofs, type, arg_types=arg_types))

def compile_add_loop_token(loop, descr):
    if we_are_translated():
        raise ValueError("CALL_ASSEMBLER not supported")
    loop = _from_opaque(loop)
    op = loop.operations[-1]
    op.descr = weakref.ref(descr)

TARGET_TOKENS = weakref.WeakKeyDictionary()

def compile_add_target_token(loop, descr, clt):
    # here, 'clt' is the compiled_loop_token of the original loop that
    # we are compiling
    loop = _from_opaque(loop)
    op = loop.operations[-1]
    descrobj = _normalize(descr)
    TARGET_TOKENS[descrobj] = loop, len(loop.operations), op.args, clt

def compile_add_var(loop, intvar):
    loop = _from_opaque(loop)
    op = loop.operations[-1]
    op.args.append(_variables[intvar])

def compile_add_int_const(loop, value):
    compile_add_ref_const(loop, value, lltype.Signed)

def compile_add_float_const(loop, value):
    compile_add_ref_const(loop, value, longlong.FLOATSTORAGE)

def compile_add_ref_const(loop, value, TYPE):
    loop = _from_opaque(loop)
    const = Constant(value)
    const.concretetype = TYPE
    op = loop.operations[-1]
    op.args.append(const)

def compile_add_int_result(loop):
    return compile_add_ref_result(loop, lltype.Signed)

def compile_add_float_result(loop):
    return compile_add_ref_result(loop, longlong.FLOATSTORAGE)

def compile_add_ref_result(loop, TYPE):
    loop = _from_opaque(loop)
    v = Variable()
    v.concretetype = TYPE
    op = loop.operations[-1]
    op.result = v
    r = len(_variables)
    _variables.append(v)
    return r

def compile_add_jump_target(loop, targettoken, source_clt):
    loop = _from_opaque(loop)
    descrobj = _normalize(targettoken)
    (loop_target, target_opindex, target_inputargs, target_clt
        ) = TARGET_TOKENS[descrobj]
    #
    try:
        assert source_clt._debug_argtypes == target_clt._debug_argtypes
    except AttributeError:   # when translated
        pass
    #
    op = loop.operations[-1]
    op.jump_target = loop_target
    op.jump_target_opindex = target_opindex
    op.jump_target_inputargs = target_inputargs
    assert op.opnum == rop.JUMP
    assert [v.concretetype for v in op.args] == (
           [v.concretetype for v in target_inputargs])
    #
    if loop_target == loop:
        log.info("compiling new loop")
    else:
        log.info("compiling new bridge")

def compile_add_guard_jump_target(loop, loop_target):
    loop = _from_opaque(loop)
    loop_target = _from_opaque(loop_target)
    op = loop.operations[-1]
    assert op.is_guard()
    op.jump_target = loop_target

def compile_add_fail(loop, fail_index):
    loop = _from_opaque(loop)
    index = len(loop.operations)-1
    op = loop.operations[index]
    op.fail_index = fail_index
    return index

def compile_add_fail_arg(loop, intvar):
    loop = _from_opaque(loop)
    op = loop.operations[-1]
    if op.fail_args is None:
        op.fail_args = []
    if intvar == -1:
        op.fail_args.append(None)
    else:
        op.fail_args.append(_variables[intvar])

def compile_redirect_fail(old_loop, old_index, new_loop):
    old_loop = _from_opaque(old_loop)
    new_loop = _from_opaque(new_loop)
    guard_op = old_loop.operations[old_index]
    assert guard_op.is_guard()
    guard_op.jump_target = new_loop
    # check that the bridge's inputargs are of the correct number and
    # kind for the guard
    if guard_op.fail_args is not None:
        argkinds = [v.concretetype for v in guard_op.fail_args if v]
    else:
        argkinds = []
    assert argkinds == [v.concretetype for v in new_loop.inputargs]

# ------------------------------

class Frame(object):
    OPHANDLERS = [None] * (rop._LAST+1)

    def __init__(self, cpu):
        self.verbose = False
        self.cpu = cpu
        self.opindex = 1
        self._forced = False
        self._may_force = -1

    def getenv(self, v):
        from pypy.jit.backend.llgraph.runner import Descr
        if isinstance(v, Constant):
            return v.value
        elif isinstance(v, Descr):
            return v
        else:
            return self.env[v]

    def _populate_fail_args(self, op, skip=None):
        fail_args = []
        if op.fail_args:
            for fail_arg in op.fail_args:
                if fail_arg is None:
                    fail_args.append(None)
                elif fail_arg is skip:
                    fail_args.append(fail_arg.concretetype._defl())
                else:
                    fail_args.append(self.getenv(fail_arg))
        self.fail_args = fail_args
        self.fail_index = op.fail_index

    def execute(self):
        """Execute all operations in a loop,
        possibly following to other loops as well.
        """
        global _last_exception
        assert _last_exception is None, "exception left behind"
        verbose = True
        self.opindex = 0
        while True:
            assert not self.loop.has_been_freed
            op = self.loop.operations[self.opindex]
            args = [self.getenv(v) for v in op.args]
            if not op.is_final():
                try:
                    result = self.execute_operation(op.opnum, args, op.descr,
                                                    verbose)
                except GuardFailed:
                    assert op.is_guard()
                    _stats.exec_conditional_jumps += 1
                    if op.jump_target is not None:
                        # a patched guard, pointing to further code
                        if op.fail_args:
                            args = [self.getenv(v) for v in op.fail_args if v]
                        else:
                            args = []
                        assert len(op.jump_target.inputargs) == len(args)
                        self.env = dict(zip(op.jump_target.inputargs, args))
                        self.loop = op.jump_target
                        self.opindex = 0
                        continue
                    else:
                        self._populate_fail_args(op)
                        # a non-patched guard
                        if self.verbose:
                            log.trace('failed: %s' % (
                                ', '.join(map(str, fail_args)),))
                        return op.fail_index
                #verbose = self.verbose
                assert (result is None) == (op.result is None)
                if op.result is not None:
                    RESTYPE = op.result.concretetype
                    if RESTYPE is lltype.Signed:
                        x = self.as_int(result)
                    elif RESTYPE is llmemory.GCREF:
                        x = self.as_ptr(result)
                    elif RESTYPE is ootype.Object:
                        x = self.as_object(result)
                    elif RESTYPE is longlong.FLOATSTORAGE:
                        x = self.as_floatstorage(result)
                    else:
                        raise Exception("op.result.concretetype is %r"
                                        % (RESTYPE,))
                    self.env[op.result] = x
                self.opindex += 1
                continue
            if op.opnum == rop.JUMP:
                inputargs = op.jump_target_inputargs
                assert len(inputargs) == len(args)
                self.env = dict(zip(inputargs, args))
                self.loop = op.jump_target
                self.opindex = op.jump_target_opindex
                _stats.exec_jumps += 1
            elif op.opnum == rop.FINISH:
                if self.verbose:
                    log.trace('finished: %s' % (
                        ', '.join(map(str, args)),))
                self.fail_args = args
                return op.fail_index

            else:
                assert 0, "unknown final operation %d" % (op.opnum,)

    def execute_operation(self, opnum, values, descr, verbose):
        """Execute a single operation.
        """
        ophandler = self.OPHANDLERS[opnum]
        if ophandler is None:
            self._define_impl(opnum)
            ophandler = self.OPHANDLERS[opnum]
            assert ophandler is not None, "missing impl for op %d" % opnum
        opname = resoperation.opname[opnum].lower()
        exec_counters = _stats.exec_counters
        exec_counters[opname] = exec_counters.get(opname, 0) + 1
        for i in range(len(values)):
            if isinstance(values[i], ComputedIntSymbolic):
                values[i] = values[i].compute_fn()
        res = NotImplemented
        try:
            res = ophandler(self, descr, *values)
        finally:
            if 0:     # if verbose:
                argtypes, restype = TYPES[opname]
                if res is None:
                    resdata = ''
                elif res is NotImplemented:
                    resdata = '*fail*'
                else:
                    resdata = '-> ' + repr1(res, restype)
                # fish the types
                log.cpu('\t%s %s %s' % (opname, repr_list(values, argtypes),
                                        resdata))
        return res

    def as_int(self, x):
        return cast_to_int(x)

    def as_ptr(self, x):
        return cast_to_ptr(x)

    def as_object(self, x):
        return ootype.cast_to_object(x)

    def as_floatstorage(self, x):
        return cast_to_floatstorage(x)

    def log_progress(self):
        count = sum(_stats.exec_counters.values())
        count_jumps = _stats.exec_jumps
        log.trace('ran %d operations, %d jumps' % (count, count_jumps))

    # ----------

    @classmethod
    def _define_impl(cls, opnum):
        opname = resoperation.opname[opnum]
        try:
            op = getattr(cls, 'op_' + opname.lower())   # op_guard_true etc.
        except AttributeError:
            try:
                impl = globals()['do_' + opname.lower()]  # do_arraylen_gc etc.
                def op(self, descr, *args):
                    if descr is None:
                        return impl(*args)
                    else:
                        return impl(descr, *args)
            except KeyError:
                op = cls._make_impl_from_blackhole_interp(opname)
        cls.OPHANDLERS[opnum] = op

    @classmethod
    def _make_impl_from_blackhole_interp(cls, opname):
        from pypy.jit.metainterp.blackhole import BlackholeInterpreter
        name = 'bhimpl_' + opname.lower()
        func = BlackholeInterpreter.__dict__[name]
        for argtype in func.argtypes:
            assert argtype in ('i', 'r', 'f')
        #
        def _op_default_implementation(self, descr, *args):
            # for all operations implemented in the blackhole interpreter
            return func(*args)
        #
        return _op_default_implementation

    def op_label(self, _, *args):
        op = self.loop.operations[self.opindex]
        assert op.opnum == rop.LABEL
        assert len(op.args) == len(args)
        newenv = {}
        for v, value in zip(op.args, args):
            newenv[v] = value
        self.env = newenv

    def op_debug_merge_point(self, _, *args):
        from pypy.jit.metainterp.warmspot import get_stats
        try:
            stats = get_stats()
        except AttributeError:
            pass
        else:
            stats.add_merge_point_location(args[1:])
        pass

    def op_guard_true(self, _, value):
        if not value:
            raise GuardFailed

    def op_guard_false(self, _, value):
        if value:
            raise GuardFailed

    op_guard_nonnull = op_guard_true
    op_guard_isnull  = op_guard_false

    def op_guard_class(self, _, value, expected_class):
        value = lltype.cast_opaque_ptr(rclass.OBJECTPTR, value)
        expected_class = llmemory.cast_adr_to_ptr(
            llmemory.cast_int_to_adr(expected_class),
            rclass.CLASSTYPE)
        if value.typeptr != expected_class:
            raise GuardFailed

    def op_guard_nonnull_class(self, _, value, expected_class):
        if not value:
            raise GuardFailed
        self.op_guard_class(_, value, expected_class)

    def op_guard_value(self, _, value, expected_value):
        if value != expected_value:
            raise GuardFailed

    def op_guard_no_exception(self, _):
        if _last_exception:
            raise GuardFailed

    def _check_exception(self, expected_exception):
        global _last_exception
        expected_exception = self._cast_exception(expected_exception)
        assert expected_exception
        exc = _last_exception
        if exc:
            got = exc.args[0]
            # exact match!
            if got != expected_exception:
                return False
            return True
        else:
            return False

    def _cast_exception(self, exception):
        return llmemory.cast_adr_to_ptr(
            llmemory.cast_int_to_adr(exception),
            rclass.CLASSTYPE)

    def _issubclass(self, cls1, cls2):
        return rclass.ll_issubclass(cls1, cls2)

    def op_guard_exception(self, _, expected_exception):
        global _last_exception
        if not self._check_exception(expected_exception):
            raise GuardFailed
        res = _last_exception[1]
        _last_exception = None
        return res

    def op_guard_no_overflow(self, _):
        flag = self.overflow_flag
        del self.overflow_flag
        if flag:
            raise GuardFailed

    def op_guard_overflow(self, _):
        flag = self.overflow_flag
        del self.overflow_flag
        if not flag:
            raise GuardFailed

    def op_int_add_ovf(self, _, x, y):
        try:
            z = ovfcheck(x + y)
        except OverflowError:
            ovf = True
            z = 0
        else:
            ovf = False
        self.overflow_flag = ovf
        return z

    def op_int_sub_ovf(self, _, x, y):
        try:
            z = ovfcheck(x - y)
        except OverflowError:
            ovf = True
            z = 0
        else:
            ovf = False
        self.overflow_flag = ovf
        return z

    def op_int_mul_ovf(self, _, x, y):
        try:
            z = ovfcheck(x * y)
        except OverflowError:
            ovf = True
            z = 0
        else:
            ovf = False
        self.overflow_flag = ovf
        return z

    def op_keepalive(self, _, x):
        pass

    # ----------
    # delegating to the builtins do_xxx() (done automatically for simple cases)

    def op_getarrayitem_gc(self, arraydescr, array, index):
        if arraydescr.typeinfo == REF:
            return do_getarrayitem_gc_ptr(array, index)
        elif arraydescr.typeinfo == INT:
            return do_getarrayitem_gc_int(array, index)
        elif arraydescr.typeinfo == FLOAT:
            return do_getarrayitem_gc_float(array, index)
        else:
            raise NotImplementedError

    op_getarrayitem_gc_pure = op_getarrayitem_gc

    def op_getarrayitem_raw(self, arraydescr, array, index):
        if arraydescr.typeinfo == REF:
            raise NotImplementedError("getarrayitem_raw -> gcref")
        elif arraydescr.typeinfo == INT:
            return do_getarrayitem_raw_int(array, index)
        elif arraydescr.typeinfo == FLOAT:
            return do_getarrayitem_raw_float(array, index)
        else:
            raise NotImplementedError

    op_getarrayitem_raw_pure = op_getarrayitem_raw

    def op_getfield_gc(self, fielddescr, struct):
        if fielddescr.typeinfo == REF:
            return do_getfield_gc_ptr(struct, fielddescr.ofs)
        elif fielddescr.typeinfo == INT:
            return do_getfield_gc_int(struct, fielddescr.ofs)
        elif fielddescr.typeinfo == FLOAT:
            return do_getfield_gc_float(struct, fielddescr.ofs)
        else:
            raise NotImplementedError

    op_getfield_gc_pure = op_getfield_gc

    def op_getfield_raw(self, fielddescr, struct):
        if fielddescr.arg_types == 'dynamic': # abuse of .arg_types
            return do_getfield_raw_dynamic(struct, fielddescr)
        elif fielddescr.typeinfo == REF:
            return do_getfield_raw_ptr(struct, fielddescr.ofs)
        elif fielddescr.typeinfo == INT:
            return do_getfield_raw_int(struct, fielddescr.ofs)
        elif fielddescr.typeinfo == FLOAT:
            return do_getfield_raw_float(struct, fielddescr.ofs)
        else:
            raise NotImplementedError

    op_getfield_raw_pure = op_getfield_raw

    def op_new(self, size):
        return do_new(size.ofs)

    def op_new_with_vtable(self, descr, vtable):
        assert descr is None
        descr = heaptracker.vtable2descr(self.cpu, vtable)
        result = do_new(descr.ofs)
        value = lltype.cast_opaque_ptr(rclass.OBJECTPTR, result)
        value.typeptr = cast_from_int(rclass.CLASSTYPE, vtable)
        return result

    def op_setarrayitem_gc(self, arraydescr, array, index, newvalue):
        if arraydescr.typeinfo == REF:
            do_setarrayitem_gc_ptr(array, index, newvalue)
        elif arraydescr.typeinfo == INT:
            do_setarrayitem_gc_int(array, index, newvalue)
        elif arraydescr.typeinfo == FLOAT:
            do_setarrayitem_gc_float(array, index, newvalue)
        else:
            raise NotImplementedError

    def op_setarrayitem_raw(self, arraydescr, array, index, newvalue):
        if arraydescr.typeinfo == REF:
            raise NotImplementedError("setarrayitem_raw <- gcref")
        elif arraydescr.typeinfo == INT:
            do_setarrayitem_raw_int(array, index, newvalue)
        elif arraydescr.typeinfo == FLOAT:
            do_setarrayitem_raw_float(array, index, newvalue)
        else:
            raise NotImplementedError

    def op_getinteriorfield_gc(self, descr, array, index):
        if descr.typeinfo == REF:
            return do_getinteriorfield_gc_ptr(array, index, descr.ofs)
        elif descr.typeinfo == INT:
            return do_getinteriorfield_gc_int(array, index, descr.ofs)
        elif descr.typeinfo == FLOAT:
            return do_getinteriorfield_gc_float(array, index, descr.ofs)
        else:
            raise NotImplementedError

    def op_getinteriorfield_raw(self, descr, array, index):
        if descr.typeinfo == REF:
            return do_getinteriorfield_raw_ptr(array, index, descr.width, descr.ofs)
        elif descr.typeinfo == INT:
            return do_getinteriorfield_raw_int(array, index, descr.width, descr.ofs)
        elif descr.typeinfo == FLOAT:
            return do_getinteriorfield_raw_float(array, index, descr.width, descr.ofs)
        else:
            raise NotImplementedError

    def op_setinteriorfield_gc(self, descr, array, index, newvalue):
        if descr.typeinfo == REF:
            return do_setinteriorfield_gc_ptr(array, index, descr.ofs,
                                              newvalue)
        elif descr.typeinfo == INT:
            return do_setinteriorfield_gc_int(array, index, descr.ofs,
                                              newvalue)
        elif descr.typeinfo == FLOAT:
            return do_setinteriorfield_gc_float(array, index, descr.ofs,
                                                newvalue)
        else:
            raise NotImplementedError

    def op_setinteriorfield_raw(self, descr, array, index, newvalue):
        if descr.typeinfo == REF:
            return do_setinteriorfield_raw_ptr(array, index, newvalue, descr.width, descr.ofs)
        elif descr.typeinfo == INT:
            return do_setinteriorfield_raw_int(array, index, newvalue, descr.width, descr.ofs)
        elif descr.typeinfo == FLOAT:
            return do_setinteriorfield_raw_float(array, index, newvalue, descr.width, descr.ofs)
        else:
            raise NotImplementedError

    def op_setfield_gc(self, fielddescr, struct, newvalue):
        if fielddescr.typeinfo == REF:
            do_setfield_gc_ptr(struct, fielddescr.ofs, newvalue)
        elif fielddescr.typeinfo == INT:
            do_setfield_gc_int(struct, fielddescr.ofs, newvalue)
        elif fielddescr.typeinfo == FLOAT:
            do_setfield_gc_float(struct, fielddescr.ofs, newvalue)
        else:
            raise NotImplementedError

    def op_setfield_raw(self, fielddescr, struct, newvalue):
        if fielddescr.arg_types == 'dynamic': # abuse of .arg_types
            do_setfield_raw_dynamic(struct, fielddescr, newvalue)
        elif fielddescr.typeinfo == REF:
            do_setfield_raw_ptr(struct, fielddescr.ofs, newvalue)
        elif fielddescr.typeinfo == INT:
            do_setfield_raw_int(struct, fielddescr.ofs, newvalue)
        elif fielddescr.typeinfo == FLOAT:
            do_setfield_raw_float(struct, fielddescr.ofs, newvalue)
        else:
            raise NotImplementedError

    def op_call(self, calldescr, func, *args):
        return self._do_call(calldescr, func, args, call_with_llptr=False)

    def op_call_release_gil(self, calldescr, func, *args):
        return self._do_call(calldescr, func, args, call_with_llptr=True)

    def _do_call(self, calldescr, func, args, call_with_llptr):
        global _last_exception
        assert _last_exception is None, "exception left behind"
        assert _call_args_i == _call_args_r == _call_args_f == []
        args_in_order = []
        for x in args:
            T = lltype.typeOf(x)
            if T is lltype.Signed:
                args_in_order.append('i')
                _call_args_i.append(x)
            elif T == llmemory.GCREF:
                args_in_order.append('r')
                _call_args_r.append(x)
            elif T is longlong.FLOATSTORAGE:
                args_in_order.append('f')
                _call_args_f.append(x)
            else:
                raise TypeError(x)
        try:
            return _do_call_common(func, args_in_order, calldescr,
                                   call_with_llptr)
        except LLException, lle:
            _last_exception = lle
            d = {'v': None,
                 REF: lltype.nullptr(llmemory.GCREF.TO),
                 INT: 0,
                 FLOAT: 0.0}
            return d[calldescr.typeinfo]

    def op_cond_call_gc_wb(self, descr, a, b):
        py.test.skip("cond_call_gc_wb not supported")

    def op_cond_call_gc_wb_array(self, descr, a, b, c):
        py.test.skip("cond_call_gc_wb_array not supported")

    def op_oosend(self, descr, obj, *args):
        raise NotImplementedError("oosend for lltype backend??")

    op_oosend_pure = op_oosend

    def op_new_array(self, arraydescr, count):
        return do_new_array(arraydescr.ofs, count)

    def op_force_token(self, descr):
        opaque_frame = _to_opaque(self)
        return llmemory.cast_ptr_to_adr(opaque_frame)

    def op_read_timestamp(self, descr):
        return read_timestamp()

    def op_call_may_force(self, calldescr, func, *args):
        assert not self._forced
        self._may_force = self.opindex
        try:
            return self.op_call(calldescr, func, *args)
        finally:
            self._may_force = -1

    def op_call_assembler(self, wref_loop_token, *args):
        if we_are_translated():
            raise ValueError("CALL_ASSEMBLER not supported")
        return self._do_call_assembler(wref_loop_token, *args)

    def _do_call_assembler(self, wref_loop_token, *args):
        global _last_exception
        loop_token = wref_loop_token()
        assert loop_token, "CALL_ASSEMBLER to a target that already died"
        ctl = loop_token.compiled_loop_token
        if hasattr(ctl, 'redirected'):
            return self._do_call_assembler(ctl.redirected, *args)
        assert not self._forced
        self._may_force = self.opindex
        try:
            inpargs = _from_opaque(ctl.compiled_version).inputargs
            assert len(inpargs) == len(args)
            for i, inparg in enumerate(inpargs):
                TYPE = inparg.concretetype
                if TYPE is lltype.Signed:
                    set_future_value_int(i, args[i])
                elif isinstance(TYPE, lltype.Ptr):
                    set_future_value_ref(i, args[i])
                elif TYPE is longlong.FLOATSTORAGE:
                    set_future_value_float(i, args[i])
                else:
                    raise Exception("Nonsense type %s" % TYPE)

            failindex = self.cpu._execute_token(loop_token)
            jd = loop_token.outermost_jitdriver_sd
            assert jd is not None, ("call_assembler(): the loop_token needs "
                                    "to have 'outermost_jitdriver_sd'")
            if jd.index_of_virtualizable != -1:
                vable = args[jd.index_of_virtualizable]
            else:
                vable = lltype.nullptr(llmemory.GCREF.TO)
            #
            # Emulate the fast path
            if failindex == self.cpu.done_with_this_frame_int_v:
                reset_vable(jd, vable)
                return self.cpu.get_latest_value_int(0)
            if failindex == self.cpu.done_with_this_frame_ref_v:
                reset_vable(jd, vable)
                return self.cpu.get_latest_value_ref(0)
            if failindex == self.cpu.done_with_this_frame_float_v:
                reset_vable(jd, vable)
                return self.cpu.get_latest_value_float(0)
            if failindex == self.cpu.done_with_this_frame_void_v:
                reset_vable(jd, vable)
                return None
            #
            assembler_helper_ptr = jd.assembler_helper_adr.ptr  # fish
            try:
                return assembler_helper_ptr(failindex, vable)
            except LLException, lle:
                assert _last_exception is None, "exception left behind"
                _last_exception = lle
                # fish op
                op = self.loop.operations[self.opindex]
                if op.result is not None:
                    return 0
        finally:
            self._may_force = -1

    def op_guard_not_forced(self, descr):
        forced = self._forced
        self._forced = False
        if forced:
            raise GuardFailed

    def op_guard_not_invalidated(self, descr):
        if self.loop.invalid:
            raise GuardFailed

class OOFrame(Frame):

    OPHANDLERS = [None] * (rop._LAST+1)

    def op_new_with_vtable(self, descr, vtable):
        assert descr is None
        typedescr = get_class_size(self.memocast, vtable)
        return ootype.cast_to_object(ootype.new(typedescr.TYPE))

    def op_new_array(self, typedescr, count):
        res = ootype.oonewarray(typedescr.ARRAY, count)
        return ootype.cast_to_object(res)

    def op_getfield_gc(self, fielddescr, obj):
        TYPE = fielddescr.TYPE
        fieldname = fielddescr.fieldname
        _, T = TYPE._lookup_field(fieldname)
        obj = ootype.cast_from_object(TYPE, obj)
        res = getattr(obj, fieldname)
        if isinstance(T, ootype.OOType):
            return ootype.cast_to_object(res)
        return res

    op_getfield_gc_pure = op_getfield_gc

    def op_setfield_gc(self, fielddescr, obj, newvalue):
        TYPE = fielddescr.TYPE
        fieldname = fielddescr.fieldname
        _, T = TYPE._lookup_field(fieldname)
        obj = ootype.cast_from_object(TYPE, obj)
        if isinstance(ootype.typeOf(newvalue), ootype.OOType):
            newvalue = ootype.cast_from_object(T, newvalue)
        elif isinstance(T, lltype.Primitive):
            newvalue = lltype.cast_primitive(T, newvalue)
        setattr(obj, fieldname, newvalue)

    def op_getarrayitem_gc(self, typedescr, obj, index):
        array = ootype.cast_from_object(typedescr.ARRAY, obj)
        res = array.ll_getitem_fast(index)
        if isinstance(typedescr.TYPE, ootype.OOType):
            return ootype.cast_to_object(res)
        return res

    op_getarrayitem_gc_pure = op_getarrayitem_gc

    def op_setarrayitem_gc(self, typedescr, obj, index, objnewvalue):
        array = ootype.cast_from_object(typedescr.ARRAY, obj)
        if ootype.typeOf(objnewvalue) == ootype.Object:
            newvalue = ootype.cast_from_object(typedescr.TYPE, objnewvalue)
        else:
            newvalue = objnewvalue
        array.ll_setitem_fast(index, newvalue)

    def op_arraylen_gc(self, typedescr, obj):
        array = ootype.cast_from_object(typedescr.ARRAY, obj)
        return array.ll_length()

    def op_call(self, calldescr, func, *args):
        sm = ootype.cast_from_object(calldescr.FUNC, func)
        newargs = cast_call_args(calldescr.FUNC.ARGS, args)
        res = call_maybe_on_top_of_llinterp(sm, newargs)
        if isinstance(calldescr.FUNC.RESULT, ootype.OOType):
            return ootype.cast_to_object(res)
        return res

    def op_oosend(self, descr, obj, *args):
        METH = descr.METH
        obj = ootype.cast_from_object(descr.SELFTYPE, obj)
        meth = getattr(obj, descr.methname)
        newargs = cast_call_args(METH.ARGS, args)
        res = call_maybe_on_top_of_llinterp(meth, newargs)
        if isinstance(METH.RESULT, ootype.OOType):
            return ootype.cast_to_object(res)
        return res

    op_oosend_pure = op_oosend

    def op_guard_class(self, _, value, expected_class):
        value = ootype.cast_from_object(ootype.ROOT, value)
        expected_class = ootype.cast_from_object(ootype.Class, expected_class)
        if ootype.classof(value) is not expected_class:
            raise GuardFailed

    def op_runtimenew(self, _, cls):
        cls = ootype.cast_from_object(ootype.Class, cls)
        res = ootype.runtimenew(cls)
        return ootype.cast_to_object(res)

    def op_instanceof(self, typedescr, obj):
        inst = ootype.cast_from_object(ootype.ROOT, obj)
        return ootype.instanceof(inst, typedescr.TYPE)

    def op_subclassof(self, _, obj1, obj2):
        cls1 = ootype.cast_from_object(ootype.Class, obj1)
        cls2 = ootype.cast_from_object(ootype.Class, obj2)
        return ootype.subclassof(cls1, cls2)

    def _cast_exception(self, exception):
        return ootype.cast_from_object(ootype.Class, exception)

    def _issubclass(self, cls1, cls2):
        return ootype.subclassof(cls1, cls2)

# ____________________________________________________________

def cast_to_int(x):
    TP = lltype.typeOf(x)
    if isinstance(TP, lltype.Ptr):
        return heaptracker.adr2int(llmemory.cast_ptr_to_adr(x))
    if TP == llmemory.Address:
        return heaptracker.adr2int(x)
    if TP is lltype.SingleFloat:
        return longlong.singlefloat2int(x)
    return lltype.cast_primitive(lltype.Signed, x)

def cast_from_int(TYPE, x):
    if isinstance(TYPE, lltype.Ptr):
        if isinstance(x, (int, long, llmemory.AddressAsInt)):
            x = llmemory.cast_int_to_adr(x)
        if TYPE is rffi.VOIDP or (
                hasattr(TYPE.TO, '_hints') and
                TYPE.TO._hints.get("uncast_on_llgraph")):
            # assume that we want a "C-style" cast, without typechecking the value
            return rffi.cast(TYPE, x)
        return llmemory.cast_adr_to_ptr(x, TYPE)
    elif TYPE == llmemory.Address:
        if isinstance(x, (int, long, llmemory.AddressAsInt)):
            x = llmemory.cast_int_to_adr(x)
        assert lltype.typeOf(x) == llmemory.Address
        return x
    elif TYPE is lltype.SingleFloat:
        assert lltype.typeOf(x) is lltype.Signed
        return longlong.int2singlefloat(x)
    else:
        if lltype.typeOf(x) == llmemory.Address:
            x = heaptracker.adr2int(x)
        return lltype.cast_primitive(TYPE, x)

def cast_to_ptr(x):
    assert isinstance(lltype.typeOf(x), lltype.Ptr)
    return lltype.cast_opaque_ptr(llmemory.GCREF, x)

def cast_from_ptr(TYPE, x):
    return lltype.cast_opaque_ptr(TYPE, x)

def cast_to_floatstorage(x):
    if isinstance(x, float):
        return longlong.getfloatstorage(x)      # common case
    if IS_32_BIT:
        assert longlong.supports_longlong
        if isinstance(x, r_longlong):
            return x
        if isinstance(x, r_ulonglong):
            return rffi.cast(lltype.SignedLongLong, x)
    raise TypeError(type(x))

def cast_from_floatstorage(TYPE, x):
    assert isinstance(x, longlong.r_float_storage)
    if TYPE is lltype.Float:
        return longlong.getrealfloat(x)
    if longlong.is_longlong(TYPE):
        return rffi.cast(TYPE, x)
    raise TypeError(TYPE)


def new_frame(is_oo, cpu):
    if is_oo:
        frame = OOFrame(cpu)
    else:
        frame = Frame(cpu)
    return _to_opaque(frame)

_future_values = []

def frame_clear(frame, loop):
    frame = _from_opaque(frame)
    loop = _from_opaque(loop)
    assert len(_future_values) == len(loop.inputargs)
    frame.loop = loop
    frame.env = {}
    for i in range(len(loop.inputargs)):
        expected_type = loop.inputargs[i].concretetype
        assert lltype.typeOf(_future_values[i]) == expected_type
        frame.env[loop.inputargs[i]] = _future_values[i]
    del _future_values[:]

def set_future_value_int(index, value):
    assert lltype.typeOf(value) is lltype.Signed
    set_future_value_ref(index, value)

def set_future_value_float(index, value):
    assert isinstance(value, longlong.r_float_storage)
    set_future_value_ref(index, value)

def set_future_value_ref(index, value):
    del _future_values[index:]
    assert len(_future_values) == index
    _future_values.append(value)

def frame_execute(frame):
    frame = _from_opaque(frame)
    if frame.verbose:
        values = [frame.env[v] for v in frame.loop.inputargs]
        log.trace('Entering CPU frame <- %r' % (values,))
    try:
        result = frame.execute()
        if frame.verbose:
            log.trace('Leaving CPU frame -> #%d' % (result,))
            frame.log_progress()
    except Exception, e:
        log.ERROR('%s in CPU frame: %s' % (e.__class__.__name__, e))
        # Only invoke pdb when io capturing is not on otherwise py.io complains.
        if py.test.config.option.capture == 'no':
            import sys, pdb
            pdb.post_mortem(sys.exc_info()[2])
        raise
    del frame.env
    return result

def frame_int_getvalue(frame, num):
    frame = _from_opaque(frame)
    assert num >= 0
    x = frame.fail_args[num]
    assert lltype.typeOf(x) is lltype.Signed
    return x

def frame_float_getvalue(frame, num):
    frame = _from_opaque(frame)
    assert num >= 0
    x = frame.fail_args[num]
    assert lltype.typeOf(x) is longlong.FLOATSTORAGE
    return x

def frame_ptr_getvalue(frame, num):
    frame = _from_opaque(frame)
    assert num >= 0
    x = frame.fail_args[num]
    assert lltype.typeOf(x) == llmemory.GCREF
    return x

def frame_get_value_count(frame):
    frame = _from_opaque(frame)
    return len(frame.fail_args)

def frame_clear_latest_values(frame, count):
    frame = _from_opaque(frame)
    assert count == len(frame.fail_args)
    del frame.fail_args

_last_exception = None

def grab_exc_value():
    global _last_exception
    if _last_exception is not None:
        result = _last_exception.args[1]
        _last_exception = None
        return lltype.cast_opaque_ptr(llmemory.GCREF, result)
    else:
        return lltype.nullptr(llmemory.GCREF.TO)

##_pseudo_exceptions = {}

##def _get_error(Class):
##    if _llinterp.typer is not None:
##        llframe = _llinterp.frame_class(None, None, _llinterp)
##        try:
##            llframe.make_llexception(Class())
##        except LLException, e:
##            return e
##        else:
##            assert 0, "should have raised"
##    else:
##        # for tests, a random emulated ll_inst will do
##        if Class not in _pseudo_exceptions:
##            ll_inst = lltype.malloc(rclass.OBJECT, zero=True)
##            ll_inst.typeptr = lltype.malloc(rclass.OBJECT_VTABLE,
##                                            immortal=True)
##            _pseudo_exceptions[Class] = LLException(ll_inst.typeptr, ll_inst)
##        return _pseudo_exceptions[Class]

##def get_overflow_error_value():
##    return lltype.cast_opaque_ptr(llmemory.GCREF,
##                                  _get_error(OverflowError).args[1])

def force(opaque_frame):
    frame = _from_opaque(opaque_frame)
    assert not frame._forced
    frame._forced = True
    assert frame._may_force >= 0
    call_op = frame.loop.operations[frame._may_force]
    guard_op = frame.loop.operations[frame._may_force+1]
    opnum = call_op.opnum
    assert opnum == rop.CALL_MAY_FORCE or opnum == rop.CALL_ASSEMBLER
    frame._populate_fail_args(guard_op, skip=call_op.result)
    return frame.fail_index

def get_forced_token_frame(force_token):
    opaque_frame = llmemory.cast_adr_to_ptr(force_token,
                                            lltype.Ptr(_TO_OPAQUE[Frame]))
    return opaque_frame

def get_frame_forced_token(opaque_frame):
    return llmemory.cast_ptr_to_adr(opaque_frame)

##def cast_adr_to_int(memocast, adr):
##    # xxx slow
##    assert lltype.typeOf(adr) == llmemory.Address
##    memocast = _from_opaque(memocast)
##    addresses = memocast.addresses
##    for i in xrange(len(addresses)-1, -1, -1):
##        if addresses[i] == adr:
##            return i
##    i = len(addresses)
##    addresses.append(adr)
##    return i

##def cast_int_to_adr(memocast, int):
##    memocast = _from_opaque(memocast)
##    assert 0 <= int < len(memocast.addresses)
##    return memocast.addresses[int]

##def get_class_size(memocast, vtable):
##    memocast = _from_opaque(memocast)
##    retur…