/pypy/jit/metainterp/pyjitpl.py

Large files files are truncated, but you can click here to view the full file

import py, sys
from pypy.rpython.lltypesystem import lltype, rclass
from pypy.rlib.objectmodel import we_are_translated
from pypy.rlib.unroll import unrolling_iterable
from pypy.rlib.debug import debug_start, debug_stop, debug_print
from pypy.rlib.debug import make_sure_not_resized
from pypy.rlib import nonconst, rstack

from pypy.jit.metainterp import history, compile, resume
from pypy.jit.metainterp.history import Const, ConstInt, ConstPtr, ConstFloat
from pypy.jit.metainterp.history import Box, TargetToken
from pypy.jit.metainterp.resoperation import rop
from pypy.jit.metainterp import executor
from pypy.jit.metainterp.logger import Logger
from pypy.jit.metainterp.jitprof import EmptyProfiler
from pypy.jit.metainterp.jitprof import GUARDS, RECORDED_OPS, ABORT_ESCAPE
from pypy.jit.metainterp.jitprof import ABORT_TOO_LONG, ABORT_BRIDGE, \
                                        ABORT_FORCE_QUASIIMMUT, ABORT_BAD_LOOP
from pypy.jit.metainterp.jitexc import JitException, get_llexception
from pypy.jit.metainterp.heapcache import HeapCache
from pypy.rlib.objectmodel import specialize
from pypy.jit.codewriter.jitcode import JitCode, SwitchDictDescr
from pypy.jit.codewriter import heaptracker
from pypy.jit.metainterp.optimizeopt.util import args_dict_box

# ____________________________________________________________

def arguments(*args):
    def decorate(func):
        func.argtypes = args
        return func
    return decorate

# ____________________________________________________________


class MIFrame(object):
    debug = False

    def __init__(self, metainterp):
        self.metainterp = metainterp
        self.registers_i = [None] * 256
        self.registers_r = [None] * 256
        self.registers_f = [None] * 256

    def setup(self, jitcode, greenkey=None):
        assert isinstance(jitcode, JitCode)
        self.jitcode = jitcode
        self.bytecode = jitcode.code
        # this is not None for frames that are recursive portal calls
        self.greenkey = greenkey
        # copy the constants in place
        self.copy_constants(self.registers_i, jitcode.constants_i, ConstInt)
        self.copy_constants(self.registers_r, jitcode.constants_r, ConstPtr)
        self.copy_constants(self.registers_f, jitcode.constants_f, ConstFloat)
        self._result_argcode = 'v'
        # for resume.py operation
        self.parent_resumedata_snapshot = None
        self.parent_resumedata_frame_info_list = None
        # counter for unrolling inlined loops
        self.unroll_iterations = 1

    @specialize.arg(3)
    def copy_constants(self, registers, constants, ConstClass):
        """Copy jitcode.constants[0] to registers[255],
                jitcode.constants[1] to registers[254],
                jitcode.constants[2] to registers[253], etc."""
        if nonconst.NonConstant(0):             # force the right type
            constants[0] = ConstClass.value     # (useful for small tests)
        i = len(constants) - 1
        while i >= 0:
            j = 255 - i
            assert j >= 0
            registers[j] = ConstClass(constants[i])
            i -= 1

    def cleanup_registers(self):
        # To avoid keeping references alive, this cleans up the registers_r.
        # It does not clear the references set by copy_constants(), but
        # these are all prebuilt constants anyway.
        for i in range(self.jitcode.num_regs_r()):
            self.registers_r[i] = None

    # ------------------------------
    # Decoding of the JitCode

    @specialize.arg(4)
    def prepare_list_of_boxes(self, outvalue, startindex, position, argcode):
        assert argcode in 'IRF'
        code = self.bytecode
        length = ord(code[position])
        position += 1
        for i in range(length):
            index = ord(code[position+i])
            if   argcode == 'I': reg = self.registers_i[index]
            elif argcode == 'R': reg = self.registers_r[index]
            elif argcode == 'F': reg = self.registers_f[index]
            else: raise AssertionError(argcode)
            outvalue[startindex+i] = reg

    def _put_back_list_of_boxes(self, outvalue, startindex, position):
        code = self.bytecode
        length = ord(code[position])
        position += 1
        for i in range(length):
            index = ord(code[position+i])
            box = outvalue[startindex+i]
            if   box.type == history.INT:   self.registers_i[index] = box
            elif box.type == history.REF:   self.registers_r[index] = box
            elif box.type == history.FLOAT: self.registers_f[index] = box
            else: raise AssertionError(box.type)

    def get_current_position_info(self):
        return self.jitcode.get_live_vars_info(self.pc)

    def get_list_of_active_boxes(self, in_a_call):
        if in_a_call:
            # If we are not the topmost frame, self._result_argcode contains
            # the type of the result of the call instruction in the bytecode.
            # We use it to clear the box that will hold the result: this box
            # is not defined yet.
            argcode = self._result_argcode
            index = ord(self.bytecode[self.pc - 1])
            if   argcode == 'i': self.registers_i[index] = history.CONST_FALSE
            elif argcode == 'r': self.registers_r[index] = history.CONST_NULL
            elif argcode == 'f': self.registers_f[index] = history.CONST_FZERO
            self._result_argcode = '?'     # done
        #
        info = self.get_current_position_info()
        start_i = 0
        start_r = start_i + info.get_register_count_i()
        start_f = start_r + info.get_register_count_r()
        total   = start_f + info.get_register_count_f()
        # allocate a list of the correct size
        env = [None] * total
        make_sure_not_resized(env)
        # fill it now
        for i in range(info.get_register_count_i()):
            index = info.get_register_index_i(i)
            env[start_i + i] = self.registers_i[index]
        for i in range(info.get_register_count_r()):
            index = info.get_register_index_r(i)
            env[start_r + i] = self.registers_r[index]
        for i in range(info.get_register_count_f()):
            index = info.get_register_index_f(i)
            env[start_f + i] = self.registers_f[index]
        return env

    def replace_active_box_in_frame(self, oldbox, newbox):
        if isinstance(oldbox, history.BoxInt):
            count = self.jitcode.num_regs_i()
            registers = self.registers_i
        elif isinstance(oldbox, history.BoxPtr):
            count = self.jitcode.num_regs_r()
            registers = self.registers_r
        elif isinstance(oldbox, history.BoxFloat):
            count = self.jitcode.num_regs_f()
            registers = self.registers_f
        else:
            assert 0, oldbox
        for i in range(count):
            if registers[i] is oldbox:
                registers[i] = newbox
        if not we_are_translated():
            for b in registers[count:]:
                assert not oldbox.same_box(b)


    def make_result_of_lastop(self, resultbox):
        got_type = resultbox.type
        # XXX disabled for now, conflicts with str_guard_value
        #if not we_are_translated():
        #    typeof = {'i': history.INT,
        #              'r': history.REF,
        #              'f': history.FLOAT}
        #    assert typeof[self.jitcode._resulttypes[self.pc]] == got_type
        target_index = ord(self.bytecode[self.pc-1])
        if got_type == history.INT:
            self.registers_i[target_index] = resultbox
        elif got_type == history.REF:
            #debug_print(' ->',
            #            llmemory.cast_ptr_to_adr(resultbox.getref_base()))
            self.registers_r[target_index] = resultbox
        elif got_type == history.FLOAT:
            self.registers_f[target_index] = resultbox
        else:
            raise AssertionError("bad result box type")

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

    for _opimpl in ['int_add', 'int_sub', 'int_mul', 'int_floordiv', 'int_mod',
                    'int_lt', 'int_le', 'int_eq',
                    'int_ne', 'int_gt', 'int_ge',
                    'int_and', 'int_or', 'int_xor',
                    'int_rshift', 'int_lshift', 'uint_rshift',
                    'uint_lt', 'uint_le', 'uint_gt', 'uint_ge',
                    'uint_floordiv',
                    'float_add', 'float_sub', 'float_mul', 'float_truediv',
                    'float_lt', 'float_le', 'float_eq',
                    'float_ne', 'float_gt', 'float_ge',
                    'ptr_eq', 'ptr_ne', 'instance_ptr_eq', 'instance_ptr_ne',
                    ]:
        exec py.code.Source('''
            @arguments("box", "box")
            def opimpl_%s(self, b1, b2):
                return self.execute(rop.%s, b1, b2)
        ''' % (_opimpl, _opimpl.upper())).compile()

    for _opimpl in ['int_add_ovf', 'int_sub_ovf', 'int_mul_ovf']:
        exec py.code.Source('''
            @arguments("box", "box")
            def opimpl_%s(self, b1, b2):
                self.metainterp.clear_exception()
                resbox = self.execute(rop.%s, b1, b2)
                self.make_result_of_lastop(resbox)  # same as execute_varargs()
                if not isinstance(resbox, Const):
                    self.metainterp.handle_possible_overflow_error()
                return resbox
        ''' % (_opimpl, _opimpl.upper())).compile()

    for _opimpl in ['int_is_true', 'int_is_zero', 'int_neg', 'int_invert',
                    'cast_float_to_int', 'cast_int_to_float',
                    'cast_float_to_singlefloat', 'cast_singlefloat_to_float',
                    'float_neg', 'float_abs',
                    'cast_ptr_to_int', 'cast_int_to_ptr',
                    ]:
        exec py.code.Source('''
            @arguments("box")
            def opimpl_%s(self, b):
                return self.execute(rop.%s, b)
        ''' % (_opimpl, _opimpl.upper())).compile()

    @arguments("box")
    def opimpl_ptr_nonzero(self, box):
        return self.execute(rop.PTR_NE, box, history.CONST_NULL)

    @arguments("box")
    def opimpl_ptr_iszero(self, box):
        return self.execute(rop.PTR_EQ, box, history.CONST_NULL)

    @arguments("box")
    def opimpl_mark_opaque_ptr(self, box):
        return self.execute(rop.MARK_OPAQUE_PTR, box)

    @arguments("box", "box")
    def opimpl_record_known_class(self, box, clsbox):
        from pypy.rpython.lltypesystem import llmemory
        if self.metainterp.heapcache.is_class_known(box):
            return
        adr = clsbox.getaddr()
        bounding_class = llmemory.cast_adr_to_ptr(adr, rclass.CLASSTYPE)
        if bounding_class.subclassrange_max - bounding_class.subclassrange_min == 1:
            # precise class knowledge, this can be used
            self.execute(rop.RECORD_KNOWN_CLASS, box, clsbox)
            self.metainterp.heapcache.class_now_known(box)

    @arguments("box")
    def _opimpl_any_return(self, box):
        self.metainterp.finishframe(box)

    opimpl_int_return = _opimpl_any_return
    opimpl_ref_return = _opimpl_any_return
    opimpl_float_return = _opimpl_any_return

    @arguments()
    def opimpl_void_return(self):
        self.metainterp.finishframe(None)

    @arguments("box")
    def _opimpl_any_copy(self, box):
        return box

    opimpl_int_copy   = _opimpl_any_copy
    opimpl_ref_copy   = _opimpl_any_copy
    opimpl_float_copy = _opimpl_any_copy

    @arguments("box")
    def _opimpl_any_push(self, box):
        self.pushed_box = box

    opimpl_int_push   = _opimpl_any_push
    opimpl_ref_push   = _opimpl_any_push
    opimpl_float_push = _opimpl_any_push

    @arguments()
    def _opimpl_any_pop(self):
        box = self.pushed_box
        self.pushed_box = None
        return box

    opimpl_int_pop   = _opimpl_any_pop
    opimpl_ref_pop   = _opimpl_any_pop
    opimpl_float_pop = _opimpl_any_pop

    @arguments("label")
    def opimpl_catch_exception(self, target):
        """This is a no-op when run normally.  We can check that
        last_exc_value_box is None; it should have been set to None
        by the previous instruction.  If the previous instruction
        raised instead, finishframe_exception() should have been
        called and we would not be there."""
        assert self.metainterp.last_exc_value_box is None

    @arguments("label")
    def opimpl_goto(self, target):
        self.pc = target

    @arguments("box", "label")
    def opimpl_goto_if_not(self, box, target):
        switchcase = box.getint()
        if switchcase:
            opnum = rop.GUARD_TRUE
        else:
            opnum = rop.GUARD_FALSE
        self.generate_guard(opnum, box)
        if not switchcase:
            self.pc = target

    @arguments("box", "label")
    def opimpl_goto_if_not_int_is_true(self, box, target):
        condbox = self.execute(rop.INT_IS_TRUE, box)
        self.opimpl_goto_if_not(condbox, target)

    @arguments("box", "label")
    def opimpl_goto_if_not_int_is_zero(self, box, target):
        condbox = self.execute(rop.INT_IS_ZERO, box)
        self.opimpl_goto_if_not(condbox, target)

    for _opimpl in ['int_lt', 'int_le', 'int_eq', 'int_ne', 'int_gt', 'int_ge',
                    'ptr_eq', 'ptr_ne']:
        exec py.code.Source('''
            @arguments("box", "box", "label")
            def opimpl_goto_if_not_%s(self, b1, b2, target):
                condbox = self.execute(rop.%s, b1, b2)
                self.opimpl_goto_if_not(condbox, target)
        ''' % (_opimpl, _opimpl.upper())).compile()


    def _establish_nullity(self, box, orgpc):
        value = box.nonnull()
        if value:
            if not self.metainterp.heapcache.is_class_known(box):
                self.generate_guard(rop.GUARD_NONNULL, box, resumepc=orgpc)
        else:
            if not isinstance(box, Const):
                self.generate_guard(rop.GUARD_ISNULL, box, resumepc=orgpc)
                promoted_box = box.constbox()
                self.metainterp.replace_box(box, promoted_box)
        return value

    @arguments("orgpc", "box", "label")
    def opimpl_goto_if_not_ptr_nonzero(self, orgpc, box, target):
        if not self._establish_nullity(box, orgpc):
            self.pc = target

    @arguments("orgpc", "box", "label")
    def opimpl_goto_if_not_ptr_iszero(self, orgpc, box, target):
        if self._establish_nullity(box, orgpc):
            self.pc = target

    @arguments("box", "box", "box")
    def opimpl_int_between(self, b1, b2, b3):
        b5 = self.execute(rop.INT_SUB, b3, b1)
        if isinstance(b5, ConstInt) and b5.getint() == 1:
            # the common case of int_between(a, b, a+1) turns into just INT_EQ
            return self.execute(rop.INT_EQ, b2, b1)
        else:
            b4 = self.execute(rop.INT_SUB, b2, b1)
            return self.execute(rop.UINT_LT, b4, b5)

    @arguments("box", "descr", "orgpc")
    def opimpl_switch(self, valuebox, switchdict, orgpc):
        box = self.implement_guard_value(orgpc, valuebox)
        search_value = box.getint()
        assert isinstance(switchdict, SwitchDictDescr)
        try:
            self.pc = switchdict.dict[search_value]
        except KeyError:
            pass

    @arguments()
    def opimpl_unreachable(self):
        raise AssertionError("unreachable")

    @arguments("descr")
    def opimpl_new(self, sizedescr):
        resbox = self.execute_with_descr(rop.NEW, sizedescr)
        self.metainterp.heapcache.new(resbox)
        return resbox

    @arguments("descr")
    def opimpl_new_with_vtable(self, sizedescr):
        cpu = self.metainterp.cpu
        cls = heaptracker.descr2vtable(cpu, sizedescr)
        resbox = self.execute(rop.NEW_WITH_VTABLE, ConstInt(cls))
        self.metainterp.heapcache.new(resbox)
        self.metainterp.heapcache.class_now_known(resbox)
        return resbox

##    @FixME  #arguments("box")
##    def opimpl_runtimenew(self, classbox):
##        self.execute(rop.RUNTIMENEW, classbox)

##    @FixME  #arguments("orgpc", "box", "descr")
##    def opimpl_instanceof(self, pc, objbox, typedescr):
##        clsbox = self.cls_of_box(objbox)
##        if isinstance(objbox, Box):
##            self.generate_guard(pc, rop.GUARD_CLASS, objbox, [clsbox])
##        self.execute_with_descr(rop.INSTANCEOF, typedescr, objbox)

##    @FixME  #arguments("box", "box")
##    def opimpl_subclassof(self, box1, box2):
##        self.execute(rop.SUBCLASSOF, box1, box2)

    @arguments("descr", "box")
    def opimpl_new_array(self, itemsizedescr, lengthbox):
        resbox = self.execute_with_descr(rop.NEW_ARRAY, itemsizedescr, lengthbox)
        self.metainterp.heapcache.new_array(resbox, lengthbox)
        return resbox

    @specialize.arg(1)
    def _do_getarrayitem_gc_any(self, op, arraybox, arraydescr, indexbox):
        tobox = self.metainterp.heapcache.getarrayitem(
                arraybox, arraydescr, indexbox)
        if tobox:
            # sanity check: see whether the current array value
            # corresponds to what the cache thinks the value is
            resbox = executor.execute(self.metainterp.cpu, self.metainterp, op,
                                      arraydescr, arraybox, indexbox)
            assert resbox.constbox().same_constant(tobox.constbox())
            return tobox
        resbox = self.execute_with_descr(op, arraydescr, arraybox, indexbox)
        self.metainterp.heapcache.getarrayitem_now_known(
                arraybox, arraydescr, indexbox, resbox)
        return resbox

    @arguments("box", "descr", "box")
    def _opimpl_getarrayitem_gc_any(self, arraybox, arraydescr, indexbox):
        return self._do_getarrayitem_gc_any(rop.GETARRAYITEM_GC, arraybox, arraydescr, indexbox)

    opimpl_getarrayitem_gc_i = _opimpl_getarrayitem_gc_any
    opimpl_getarrayitem_gc_r = _opimpl_getarrayitem_gc_any
    opimpl_getarrayitem_gc_f = _opimpl_getarrayitem_gc_any

    @arguments("box", "descr", "box")
    def _opimpl_getarrayitem_raw_any(self, arraybox, arraydescr, indexbox):
        return self.execute_with_descr(rop.GETARRAYITEM_RAW,
                                       arraydescr, arraybox, indexbox)

    opimpl_getarrayitem_raw_i = _opimpl_getarrayitem_raw_any
    opimpl_getarrayitem_raw_f = _opimpl_getarrayitem_raw_any

    @arguments("box", "descr", "box")
    def _opimpl_getarrayitem_gc_pure_any(self, arraybox, arraydescr, indexbox):
        return self._do_getarrayitem_gc_any(rop.GETARRAYITEM_GC_PURE, arraybox, arraydescr, indexbox)

    opimpl_getarrayitem_gc_pure_i = _opimpl_getarrayitem_gc_pure_any
    opimpl_getarrayitem_gc_pure_r = _opimpl_getarrayitem_gc_pure_any
    opimpl_getarrayitem_gc_pure_f = _opimpl_getarrayitem_gc_pure_any

    @arguments("box", "descr", "box", "box")
    def _opimpl_setarrayitem_gc_any(self, arraybox, arraydescr,
                                    indexbox, itembox):
        self.execute_with_descr(rop.SETARRAYITEM_GC, arraydescr, arraybox,
                                indexbox, itembox)
        self.metainterp.heapcache.setarrayitem(
                arraybox, arraydescr, indexbox, itembox)

    opimpl_setarrayitem_gc_i = _opimpl_setarrayitem_gc_any
    opimpl_setarrayitem_gc_r = _opimpl_setarrayitem_gc_any
    opimpl_setarrayitem_gc_f = _opimpl_setarrayitem_gc_any

    @arguments("box", "descr", "box", "box")
    def _opimpl_setarrayitem_raw_any(self, arraybox, arraydescr,
                                    indexbox, itembox):
        self.execute_with_descr(rop.SETARRAYITEM_RAW, arraydescr, arraybox,
                                indexbox, itembox)

    opimpl_setarrayitem_raw_i = _opimpl_setarrayitem_raw_any
    opimpl_setarrayitem_raw_f = _opimpl_setarrayitem_raw_any

    @arguments("box", "descr")
    def opimpl_arraylen_gc(self, arraybox, arraydescr):
        lengthbox = self.metainterp.heapcache.arraylen(arraybox)
        if lengthbox is None:
            lengthbox = self.execute_with_descr(
                    rop.ARRAYLEN_GC, arraydescr, arraybox)
            self.metainterp.heapcache.arraylen_now_known(arraybox, lengthbox)
        return lengthbox

    @arguments("orgpc", "box", "descr", "box")
    def opimpl_check_neg_index(self, orgpc, arraybox, arraydescr, indexbox):
        negbox = self.metainterp.execute_and_record(
            rop.INT_LT, None, indexbox, history.CONST_FALSE)
        negbox = self.implement_guard_value(orgpc, negbox)
        if negbox.getint():
            # the index is < 0; add the array length to it
            lengthbox = self.opimpl_arraylen_gc(arraybox, arraydescr)
            indexbox = self.metainterp.execute_and_record(
                rop.INT_ADD, None, indexbox, lengthbox)
        return indexbox

    @arguments("descr", "descr", "descr", "descr", "box")
    def opimpl_newlist(self, structdescr, lengthdescr, itemsdescr, arraydescr,
                       sizebox):
        sbox = self.opimpl_new(structdescr)
        self._opimpl_setfield_gc_any(sbox, lengthdescr, sizebox)
        abox = self.opimpl_new_array(arraydescr, sizebox)
        self._opimpl_setfield_gc_any(sbox, itemsdescr, abox)
        return sbox

    @arguments("box", "descr", "descr", "box")
    def _opimpl_getlistitem_gc_any(self, listbox, itemsdescr, arraydescr,
                                   indexbox):
        arraybox = self._opimpl_getfield_gc_any(listbox, itemsdescr)
        return self._opimpl_getarrayitem_gc_any(arraybox, arraydescr, indexbox)

    opimpl_getlistitem_gc_i = _opimpl_getlistitem_gc_any
    opimpl_getlistitem_gc_r = _opimpl_getlistitem_gc_any
    opimpl_getlistitem_gc_f = _opimpl_getlistitem_gc_any

    @arguments("box", "descr", "descr", "box", "box")
    def _opimpl_setlistitem_gc_any(self, listbox, itemsdescr, arraydescr,
                                   indexbox, valuebox):
        arraybox = self._opimpl_getfield_gc_any(listbox, itemsdescr)
        self._opimpl_setarrayitem_gc_any(arraybox, arraydescr, indexbox,
                                         valuebox)

    opimpl_setlistitem_gc_i = _opimpl_setlistitem_gc_any
    opimpl_setlistitem_gc_r = _opimpl_setlistitem_gc_any
    opimpl_setlistitem_gc_f = _opimpl_setlistitem_gc_any

    @arguments("orgpc", "box", "descr", "box")
    def opimpl_check_resizable_neg_index(self, orgpc, listbox, lengthdescr,
                                         indexbox):
        negbox = self.metainterp.execute_and_record(
            rop.INT_LT, None, indexbox, history.CONST_FALSE)
        negbox = self.implement_guard_value(orgpc, negbox)
        if negbox.getint():
            # the index is < 0; add the array length to it
            lenbox = self.metainterp.execute_and_record(
                rop.GETFIELD_GC, lengthdescr, listbox)
            indexbox = self.metainterp.execute_and_record(
                rop.INT_ADD, None, indexbox, lenbox)
        return indexbox

    @arguments("box", "descr")
    def _opimpl_getfield_gc_any(self, box, fielddescr):
        return self._opimpl_getfield_gc_any_pureornot(
                rop.GETFIELD_GC, box, fielddescr)
    opimpl_getfield_gc_i = _opimpl_getfield_gc_any
    opimpl_getfield_gc_r = _opimpl_getfield_gc_any
    opimpl_getfield_gc_f = _opimpl_getfield_gc_any

    @arguments("box", "descr")
    def _opimpl_getfield_gc_pure_any(self, box, fielddescr):
        return self._opimpl_getfield_gc_any_pureornot(
                rop.GETFIELD_GC_PURE, box, fielddescr)
    opimpl_getfield_gc_i_pure = _opimpl_getfield_gc_pure_any
    opimpl_getfield_gc_r_pure = _opimpl_getfield_gc_pure_any
    opimpl_getfield_gc_f_pure = _opimpl_getfield_gc_pure_any

    @arguments("box", "box", "descr")
    def _opimpl_getinteriorfield_gc_any(self, array, index, descr):
        return self.execute_with_descr(rop.GETINTERIORFIELD_GC, descr,
                                       array, index)
    opimpl_getinteriorfield_gc_i = _opimpl_getinteriorfield_gc_any
    opimpl_getinteriorfield_gc_f = _opimpl_getinteriorfield_gc_any
    opimpl_getinteriorfield_gc_r = _opimpl_getinteriorfield_gc_any

    @specialize.arg(1)
    def _opimpl_getfield_gc_any_pureornot(self, opnum, box, fielddescr):
        tobox = self.metainterp.heapcache.getfield(box, fielddescr)
        if tobox is not None:
            # sanity check: see whether the current struct value
            # corresponds to what the cache thinks the value is
            resbox = executor.execute(self.metainterp.cpu, self.metainterp,
                                      rop.GETFIELD_GC, fielddescr, box)
            return tobox
        resbox = self.execute_with_descr(opnum, fielddescr, box)
        self.metainterp.heapcache.getfield_now_known(box, fielddescr, resbox)
        return resbox

    @arguments("orgpc", "box", "descr")
    def _opimpl_getfield_gc_greenfield_any(self, pc, box, fielddescr):
        ginfo = self.metainterp.jitdriver_sd.greenfield_info
        if (ginfo is not None and fielddescr in ginfo.green_field_descrs
            and not self._nonstandard_virtualizable(pc, box)):
            # fetch the result, but consider it as a Const box and don't
            # record any operation
            resbox = executor.execute(self.metainterp.cpu, self.metainterp,
                                      rop.GETFIELD_GC_PURE, fielddescr, box)
            return resbox.constbox()
        # fall-back
        return self.execute_with_descr(rop.GETFIELD_GC_PURE, fielddescr, box)
    opimpl_getfield_gc_i_greenfield = _opimpl_getfield_gc_greenfield_any
    opimpl_getfield_gc_r_greenfield = _opimpl_getfield_gc_greenfield_any
    opimpl_getfield_gc_f_greenfield = _opimpl_getfield_gc_greenfield_any

    @arguments("box", "descr", "box")
    def _opimpl_setfield_gc_any(self, box, fielddescr, valuebox):
        tobox = self.metainterp.heapcache.getfield(box, fielddescr)
        if tobox is valuebox:
            return
        self.execute_with_descr(rop.SETFIELD_GC, fielddescr, box, valuebox)
        self.metainterp.heapcache.setfield(box, fielddescr, valuebox)
    opimpl_setfield_gc_i = _opimpl_setfield_gc_any
    opimpl_setfield_gc_r = _opimpl_setfield_gc_any
    opimpl_setfield_gc_f = _opimpl_setfield_gc_any

    @arguments("box", "box", "box", "descr")
    def _opimpl_setinteriorfield_gc_any(self, array, index, value, descr):
        self.execute_with_descr(rop.SETINTERIORFIELD_GC, descr,
                                array, index, value)
    opimpl_setinteriorfield_gc_i = _opimpl_setinteriorfield_gc_any
    opimpl_setinteriorfield_gc_f = _opimpl_setinteriorfield_gc_any
    opimpl_setinteriorfield_gc_r = _opimpl_setinteriorfield_gc_any


    @arguments("box", "descr")
    def _opimpl_getfield_raw_any(self, box, fielddescr):
        return self.execute_with_descr(rop.GETFIELD_RAW, fielddescr, box)
    opimpl_getfield_raw_i = _opimpl_getfield_raw_any
    opimpl_getfield_raw_r = _opimpl_getfield_raw_any
    opimpl_getfield_raw_f = _opimpl_getfield_raw_any

    @arguments("box", "descr")
    def _opimpl_getfield_raw_pure_any(self, box, fielddescr):
        return self.execute_with_descr(rop.GETFIELD_RAW_PURE, fielddescr, box)
    opimpl_getfield_raw_i_pure = _opimpl_getfield_raw_pure_any
    opimpl_getfield_raw_r_pure = _opimpl_getfield_raw_pure_any
    opimpl_getfield_raw_f_pure = _opimpl_getfield_raw_pure_any

    @arguments("box", "descr", "box")
    def _opimpl_setfield_raw_any(self, box, fielddescr, valuebox):
        self.execute_with_descr(rop.SETFIELD_RAW, fielddescr, box, valuebox)
    opimpl_setfield_raw_i = _opimpl_setfield_raw_any
    opimpl_setfield_raw_r = _opimpl_setfield_raw_any
    opimpl_setfield_raw_f = _opimpl_setfield_raw_any

    @arguments("box", "descr", "descr", "orgpc")
    def opimpl_record_quasiimmut_field(self, box, fielddescr,
                                       mutatefielddescr, orgpc):
        from pypy.jit.metainterp.quasiimmut import QuasiImmutDescr
        cpu = self.metainterp.cpu
        descr = QuasiImmutDescr(cpu, box, fielddescr, mutatefielddescr)
        self.metainterp.history.record(rop.QUASIIMMUT_FIELD, [box],
                                       None, descr=descr)
        self.generate_guard(rop.GUARD_NOT_INVALIDATED, resumepc=orgpc)

    @arguments("box", "descr", "orgpc")
    def opimpl_jit_force_quasi_immutable(self, box, mutatefielddescr, orgpc):
        # During tracing, a 'jit_force_quasi_immutable' usually turns into
        # the operations that check that the content of 'mutate_xxx' is null.
        # If it is actually not null already now, then we abort tracing.
        # The idea is that if we use 'jit_force_quasi_immutable' on a freshly
        # allocated object, then the GETFIELD_GC will know that the answer is
        # null, and the guard will be removed.  So the fact that the field is
        # quasi-immutable will have no effect, and instead it will work as a
        # regular, probably virtual, structure.
        mutatebox = self.execute_with_descr(rop.GETFIELD_GC,
                                            mutatefielddescr, box)
        if mutatebox.nonnull():
            from pypy.jit.metainterp.quasiimmut import do_force_quasi_immutable
            do_force_quasi_immutable(self.metainterp.cpu, box.getref_base(),
                                     mutatefielddescr)
            raise SwitchToBlackhole(ABORT_FORCE_QUASIIMMUT)
        self.generate_guard(rop.GUARD_ISNULL, mutatebox, resumepc=orgpc)

    def _nonstandard_virtualizable(self, pc, box):
        # returns True if 'box' is actually not the "standard" virtualizable
        # that is stored in metainterp.virtualizable_boxes[-1]
        if (self.metainterp.jitdriver_sd.virtualizable_info is None and
            self.metainterp.jitdriver_sd.greenfield_info is None):
            return True      # can occur in case of multiple JITs
        standard_box = self.metainterp.virtualizable_boxes[-1]
        if standard_box is box:
            return False
        if self.metainterp.heapcache.is_nonstandard_virtualizable(box):
            return True
        eqbox = self.metainterp.execute_and_record(rop.PTR_EQ, None,
                                                   box, standard_box)
        eqbox = self.implement_guard_value(pc, eqbox)
        isstandard = eqbox.getint()
        if isstandard:
            self.metainterp.replace_box(box, standard_box)
        else:
            self.metainterp.heapcache.nonstandard_virtualizables_now_known(box)
        return not isstandard

    def _get_virtualizable_field_index(self, fielddescr):
        # Get the index of a fielddescr.  Must only be called for
        # the "standard" virtualizable.
        vinfo = self.metainterp.jitdriver_sd.virtualizable_info
        return vinfo.static_field_by_descrs[fielddescr]

    @arguments("orgpc", "box", "descr")
    def _opimpl_getfield_vable(self, pc, box, fielddescr):
        if self._nonstandard_virtualizable(pc, box):
            return self._opimpl_getfield_gc_any(box, fielddescr)
        self.metainterp.check_synchronized_virtualizable()
        index = self._get_virtualizable_field_index(fielddescr)
        return self.metainterp.virtualizable_boxes[index]

    opimpl_getfield_vable_i = _opimpl_getfield_vable
    opimpl_getfield_vable_r = _opimpl_getfield_vable
    opimpl_getfield_vable_f = _opimpl_getfield_vable

    @arguments("orgpc", "box", "descr", "box")
    def _opimpl_setfield_vable(self, pc, box, fielddescr, valuebox):
        if self._nonstandard_virtualizable(pc, box):
            return self._opimpl_setfield_gc_any(box, fielddescr, valuebox)
        index = self._get_virtualizable_field_index(fielddescr)
        self.metainterp.virtualizable_boxes[index] = valuebox
        self.metainterp.synchronize_virtualizable()
        # XXX only the index'th field needs to be synchronized, really

    opimpl_setfield_vable_i = _opimpl_setfield_vable
    opimpl_setfield_vable_r = _opimpl_setfield_vable
    opimpl_setfield_vable_f = _opimpl_setfield_vable

    def _get_arrayitem_vable_index(self, pc, arrayfielddescr, indexbox):
        # Get the index of an array item: the index'th of the array
        # described by arrayfielddescr.  Must only be called for
        # the "standard" virtualizable.
        indexbox = self.implement_guard_value(pc, indexbox)
        vinfo = self.metainterp.jitdriver_sd.virtualizable_info
        virtualizable_box = self.metainterp.virtualizable_boxes[-1]
        virtualizable = vinfo.unwrap_virtualizable_box(virtualizable_box)
        arrayindex = vinfo.array_field_by_descrs[arrayfielddescr]
        index = indexbox.getint()
        # Support for negative index: disabled
        # (see codewriter/jtransform.py, _check_no_vable_array).
        #if index < 0:
        #    index += vinfo.get_array_length(virtualizable, arrayindex)
        assert 0 <= index < vinfo.get_array_length(virtualizable, arrayindex)
        return vinfo.get_index_in_array(virtualizable, arrayindex, index)

    @arguments("orgpc", "box", "descr", "descr", "box")
    def _opimpl_getarrayitem_vable(self, pc, box, fdescr, adescr, indexbox):
        if self._nonstandard_virtualizable(pc, box):
            arraybox = self._opimpl_getfield_gc_any(box, fdescr)
            return self._opimpl_getarrayitem_gc_any(arraybox, adescr, indexbox)
        self.metainterp.check_synchronized_virtualizable()
        index = self._get_arrayitem_vable_index(pc, fdescr, indexbox)
        return self.metainterp.virtualizable_boxes[index]

    opimpl_getarrayitem_vable_i = _opimpl_getarrayitem_vable
    opimpl_getarrayitem_vable_r = _opimpl_getarrayitem_vable
    opimpl_getarrayitem_vable_f = _opimpl_getarrayitem_vable

    @arguments("orgpc", "box", "descr", "descr", "box", "box")
    def _opimpl_setarrayitem_vable(self, pc, box, fdescr, adescr, indexbox,
                                  valuebox):
        if self._nonstandard_virtualizable(pc, box):
            arraybox = self._opimpl_getfield_gc_any(box, fdescr)
            self._opimpl_setarrayitem_gc_any(arraybox, adescr,
                                             indexbox, valuebox)
            return
        index = self._get_arrayitem_vable_index(pc, fdescr, indexbox)
        self.metainterp.virtualizable_boxes[index] = valuebox
        self.metainterp.synchronize_virtualizable()
        # XXX only the index'th field needs to be synchronized, really

    opimpl_setarrayitem_vable_i = _opimpl_setarrayitem_vable
    opimpl_setarrayitem_vable_r = _opimpl_setarrayitem_vable
    opimpl_setarrayitem_vable_f = _opimpl_setarrayitem_vable

    @arguments("orgpc", "box", "descr", "descr")
    def opimpl_arraylen_vable(self, pc, box, fdescr, adescr):
        if self._nonstandard_virtualizable(pc, box):
            arraybox = self._opimpl_getfield_gc_any(box, fdescr)
            return self.opimpl_arraylen_gc(arraybox, adescr)
        vinfo = self.metainterp.jitdriver_sd.virtualizable_info
        virtualizable_box = self.metainterp.virtualizable_boxes[-1]
        virtualizable = vinfo.unwrap_virtualizable_box(virtualizable_box)
        arrayindex = vinfo.array_field_by_descrs[fdescr]
        result = vinfo.get_array_length(virtualizable, arrayindex)
        return ConstInt(result)

    @arguments("jitcode", "boxes")
    def _opimpl_inline_call1(self, jitcode, argboxes):
        return self.metainterp.perform_call(jitcode, argboxes)
    @arguments("jitcode", "boxes2")
    def _opimpl_inline_call2(self, jitcode, argboxes):
        return self.metainterp.perform_call(jitcode, argboxes)
    @arguments("jitcode", "boxes3")
    def _opimpl_inline_call3(self, jitcode, argboxes):
        return self.metainterp.perform_call(jitcode, argboxes)

    opimpl_inline_call_r_i = _opimpl_inline_call1
    opimpl_inline_call_r_r = _opimpl_inline_call1
    opimpl_inline_call_r_v = _opimpl_inline_call1
    opimpl_inline_call_ir_i = _opimpl_inline_call2
    opimpl_inline_call_ir_r = _opimpl_inline_call2
    opimpl_inline_call_ir_v = _opimpl_inline_call2
    opimpl_inline_call_irf_i = _opimpl_inline_call3
    opimpl_inline_call_irf_r = _opimpl_inline_call3
    opimpl_inline_call_irf_f = _opimpl_inline_call3
    opimpl_inline_call_irf_v = _opimpl_inline_call3

    @arguments("box", "descr", "boxes")
    def _opimpl_residual_call1(self, funcbox, calldescr, argboxes):
        return self.do_residual_or_indirect_call(funcbox, calldescr, argboxes)
    @arguments("box", "descr", "boxes2")
    def _opimpl_residual_call2(self, funcbox, calldescr, argboxes):
        return self.do_residual_or_indirect_call(funcbox, calldescr, argboxes)
    @arguments("box", "descr", "boxes3")
    def _opimpl_residual_call3(self, funcbox, calldescr, argboxes):
        return self.do_residual_or_indirect_call(funcbox, calldescr, argboxes)

    opimpl_residual_call_r_i = _opimpl_residual_call1
    opimpl_residual_call_r_r = _opimpl_residual_call1
    opimpl_residual_call_r_v = _opimpl_residual_call1
    opimpl_residual_call_ir_i = _opimpl_residual_call2
    opimpl_residual_call_ir_r = _opimpl_residual_call2
    opimpl_residual_call_ir_v = _opimpl_residual_call2
    opimpl_residual_call_irf_i = _opimpl_residual_call3
    opimpl_residual_call_irf_r = _opimpl_residual_call3
    opimpl_residual_call_irf_f = _opimpl_residual_call3
    opimpl_residual_call_irf_v = _opimpl_residual_call3

    @arguments("int", "boxes3", "boxes3")
    def _opimpl_recursive_call(self, jdindex, greenboxes, redboxes):
        targetjitdriver_sd = self.metainterp.staticdata.jitdrivers_sd[jdindex]
        allboxes = greenboxes + redboxes
        warmrunnerstate = targetjitdriver_sd.warmstate
        assembler_call = False
        if warmrunnerstate.inlining:
            if warmrunnerstate.can_inline_callable(greenboxes):
                portal_code = targetjitdriver_sd.mainjitcode
                return self.metainterp.perform_call(portal_code, allboxes,
                                                    greenkey=greenboxes)
            assembler_call = True
            # verify that we have all green args, needed to make sure
            # that assembler that we call is still correct
            self.verify_green_args(targetjitdriver_sd, greenboxes)
        #
        return self.do_recursive_call(targetjitdriver_sd, allboxes,
                                      assembler_call)

    def do_recursive_call(self, targetjitdriver_sd, allboxes,
                          assembler_call=False):
        portal_code = targetjitdriver_sd.mainjitcode
        k = targetjitdriver_sd.portal_runner_adr
        funcbox = ConstInt(heaptracker.adr2int(k))
        return self.do_residual_call(funcbox, portal_code.calldescr, allboxes,
                                     assembler_call=assembler_call,
                                     assembler_call_jd=targetjitdriver_sd)

    opimpl_recursive_call_i = _opimpl_recursive_call
    opimpl_recursive_call_r = _opimpl_recursive_call
    opimpl_recursive_call_f = _opimpl_recursive_call
    opimpl_recursive_call_v = _opimpl_recursive_call

##    @FixME  #arguments("orgpc", "methdescr", "varargs")
##    def opimpl_oosend(self, pc, methdescr, varargs):
##        objbox = varargs[0]
##        clsbox = self.cls_of_box(objbox)
##        if isinstance(objbox, Box):
##            self.generate_guard(pc, rop.GUARD_CLASS, objbox, [clsbox])
##        oocls = clsbox.getref(ootype.Class)
##        jitcode = methdescr.get_jitcode_for_class(oocls)
##        if jitcode is not None:
##            # we should follow calls to this graph
##            return self.perform_call(jitcode, varargs)
##        else:
##            # but we should not follow calls to that graph
##            return self.execute_varargs(rop.OOSEND, varargs,
##                                        descr=methdescr, exc=True)

    @arguments("box")
    def opimpl_strlen(self, strbox):
        return self.execute(rop.STRLEN, strbox)

    @arguments("box")
    def opimpl_unicodelen(self, unicodebox):
        return self.execute(rop.UNICODELEN, unicodebox)

    @arguments("box", "box")
    def opimpl_strgetitem(self, strbox, indexbox):
        return self.execute(rop.STRGETITEM, strbox, indexbox)

    @arguments("box", "box")
    def opimpl_unicodegetitem(self, unicodebox, indexbox):
        return self.execute(rop.UNICODEGETITEM, unicodebox, indexbox)

    @arguments("box", "box", "box")
    def opimpl_strsetitem(self, strbox, indexbox, newcharbox):
        return self.execute(rop.STRSETITEM, strbox, indexbox, newcharbox)

    @arguments("box", "box", "box")
    def opimpl_unicodesetitem(self, unicodebox, indexbox, newcharbox):
        self.execute(rop.UNICODESETITEM, unicodebox, indexbox, newcharbox)

    @arguments("box")
    def opimpl_newstr(self, lengthbox):
        return self.execute(rop.NEWSTR, lengthbox)

    @arguments("box")
    def opimpl_newunicode(self, lengthbox):
        return self.execute(rop.NEWUNICODE, lengthbox)

    @arguments("box", "box", "box", "box", "box")
    def opimpl_copystrcontent(self, srcbox, dstbox, srcstartbox, dststartbox, lengthbox):
        return self.execute(rop.COPYSTRCONTENT, srcbox, dstbox, srcstartbox, dststartbox, lengthbox)

    @arguments("box", "box", "box", "box", "box")
    def opimpl_copyunicodecontent(self, srcbox, dstbox, srcstartbox, dststartbox, lengthbox):
        return self.execute(rop.COPYUNICODECONTENT, srcbox, dstbox, srcstartbox, dststartbox, lengthbox)

##    @FixME  #arguments("descr", "varargs")
##    def opimpl_residual_oosend_canraise(self, methdescr, varargs):
##        return self.execute_varargs(rop.OOSEND, varargs, descr=methdescr,
##                                    exc=True)

##    @FixME  #arguments("descr", "varargs")
##    def opimpl_residual_oosend_noraise(self, methdescr, varargs):
##        return self.execute_varargs(rop.OOSEND, varargs, descr=methdescr,
##                                    exc=False)

##    @FixME  #arguments("descr", "varargs")
##    def opimpl_residual_oosend_pure(self, methdescr, boxes):
##        return self.execute_varargs(rop.OOSEND_PURE, boxes, descr=methdescr,
##                                    exc=False)

    @arguments("orgpc", "box",)
    def _opimpl_guard_value(self, orgpc, box):
        self.implement_guard_value(orgpc, box)

    @arguments("orgpc", "box", "box", "descr")
    def opimpl_str_guard_value(self, orgpc, box, funcbox, descr):
        if isinstance(box, Const):
            return box     # no promotion needed, already a Const
        else:
            constbox = box.constbox()
            resbox = self.do_residual_call(funcbox, descr, [box, constbox])
            promoted_box = resbox.constbox()
            # This is GUARD_VALUE because GUARD_TRUE assumes the existance
            # of a label when computing resumepc
            self.generate_guard(rop.GUARD_VALUE, resbox, [promoted_box],
                                resumepc=orgpc)
            self.metainterp.replace_box(box, constbox)
            return constbox

    opimpl_int_guard_value = _opimpl_guard_value
    opimpl_ref_guard_value = _opimpl_guard_value
    opimpl_float_guard_value = _opimpl_guard_value

    @arguments("orgpc", "box")
    def opimpl_guard_class(self, orgpc, box):
        clsbox = self.cls_of_box(box)
        if not self.metainterp.heapcache.is_class_known(box):
            self.generate_guard(rop.GUARD_CLASS, box, [clsbox], resumepc=orgpc)
            self.metainterp.heapcache.class_now_known(box)
        return clsbox

    @arguments("int", "orgpc")
    def opimpl_loop_header(self, jdindex, orgpc):
        self.metainterp.seen_loop_header_for_jdindex = jdindex

    def verify_green_args(self, jitdriver_sd, varargs):
        num_green_args = jitdriver_sd.num_green_args
        assert len(varargs) == num_green_args
        for i in range(num_green_args):
            assert isinstance(varargs[i], Const)

    @arguments("orgpc", "int", "boxes3", "jitcode_position", "boxes3")
    def opimpl_jit_merge_point(self, orgpc, jdindex, greenboxes,
                               jcposition, redboxes):
        resumedescr = compile.ResumeAtPositionDescr()
        self.capture_resumedata(resumedescr, orgpc)

        any_operation = len(self.metainterp.history.operations) > 0
        jitdriver_sd = self.metainterp.staticdata.jitdrivers_sd[jdindex]
        self.verify_green_args(jitdriver_sd, greenboxes)
        self.debug_merge_point(jitdriver_sd, jdindex, self.metainterp.portal_call_depth,
                               greenboxes)
        
        if self.metainterp.seen_loop_header_for_jdindex < 0:
            if not any_operation:
                return
            if self.metainterp.portal_call_depth or not self.metainterp.get_procedure_token(greenboxes, True):
                if not jitdriver_sd.no_loop_header:
                    return
            # automatically add a loop_header if there is none
            self.metainterp.seen_loop_header_for_jdindex = jdindex
        #
        assert self.metainterp.seen_loop_header_for_jdindex == jdindex, (
            "found a loop_header for a JitDriver that does not match "
            "the following jit_merge_point's")
        self.metainterp.seen_loop_header_for_jdindex = -1

        #
        if not self.metainterp.portal_call_depth:
            assert jitdriver_sd is self.metainterp.jitdriver_sd
            # Set self.pc to point to jit_merge_point instead of just after:
            # if reached_loop_header() raises SwitchToBlackhole, then the
            # pc is still at the jit_merge_point, which is a point that is
            # much less expensive to blackhole out of.
            saved_pc = self.pc
            self.pc = orgpc
            self.metainterp.reached_loop_header(greenboxes, redboxes, resumedescr)
            self.pc = saved_pc
            # no exception, which means that the jit_merge_point did not
            # close the loop.  We have to put the possibly-modified list
            # 'redboxes' back into the registers where it comes from.
            put_back_list_of_boxes3(self, jcposition, redboxes)
        else:
            if jitdriver_sd.warmstate.should_unroll_one_iteration(greenboxes):
                if self.unroll_iterations > 0:
                    self.unroll_iterations -= 1
                    return
            # warning! careful here.  We have to return from the current
            # frame containing the jit_merge_point, and then use
            # do_recursive_call() to follow the recursive call.  This is
            # needed because do_recursive_call() will write its result
            # with make_result_of_lastop(), so the lastop must be right:
            # it must be the call to 'self', and not the jit_merge_point
            # itself, which has no result at all.
            assert len(self.metainterp.framestack) >= 2
            try:
                self.metainterp.finishframe(None)
            except ChangeFrame:
                pass
            frame = self.metainterp.framestack[-1]
            frame.do_recursive_call(jitdriver_sd, greenboxes + redboxes,
                                    assembler_call=True)
            raise ChangeFrame

    def debug_merge_point(self, jitdriver_sd, jd_index, portal_call_depth, greenkey):
        # debugging: produce a DEBUG_MERGE_POINT operation
        loc = jitdriver_sd.warmstate.get_location_str(greenkey)
        debug_print(loc)
        args = [ConstInt(jd_index), ConstInt(portal_call_depth)] + greenkey
        self.metainterp.history.record(rop.DEBUG_MERGE_POINT, args, None)

    @arguments("box", "label")
    def opimpl_goto_if_exception_mismatch(self, vtablebox, next_exc_target):
        metainterp = self.metainterp
        last_exc_value_box = metainterp.last_exc_value_box
        assert last_exc_value_box is not None
        assert metainterp.class_of_last_exc_is_const
        if not metainterp.cpu.ts.instanceOf(last_exc_value_box, vtablebox):
            self.pc = next_exc_target

    @arguments("orgpc", "box")
    def opimpl_raise(self, orgpc, exc_value_box):
        # xxx hack
        clsbox = self.cls_of_box(exc_value_box)
        self.generate_guard(rop.GUARD_CLASS, exc_value_box, [clsbox],
                            resumepc=orgpc)
        self.metainterp.class_of_last_exc_is_const = True
        self.metainterp.last_exc_value_box = exc_value_box
        self.metainterp.popframe()
        self.metainterp.finishframe_exception()

    @arguments()
    def opimpl_reraise(self):
        assert self.metainterp.last_exc_value_box is not None
        self.metainterp.popframe()
        self.metainterp.finishframe_exception()

    @arguments()
    def opimpl_last_exception(self):
        # Same comment as in opimpl_goto_if_exception_mismatch().
        exc_value_box = self.metainterp.last_exc_value_box
        assert exc_value_box is not None
        assert self.metainterp.class_of_last_exc_is_const
        return self.metainterp.cpu.ts.cls_of_box(exc_value_box)

    @arguments()
    def opimpl_last_exc_value(self):
        exc_value_box = self.metainterp.last_exc_value_box
        assert exc_value_box is not None
        return exc_value_box

    @arguments("box")
    def opimpl_debug_fatalerror(self, box):
        from pypy.rpython.lltypesystem import rstr, lloperation
        msg = box.getref(lltype.Ptr(rstr.STR))
        lloperation.llop.debug_fatalerror(msg)

    @arguments("box", "box", "box", "box", "box")
    def opimpl_jit_debug(self, stringbox, arg1box, arg2box, arg3box, arg4box):
        from pypy.rpython.lltypesystem import rstr
        from pypy.rpython.annlowlevel import hlstr
        msg = stringbox.getref(lltype.Ptr(rstr.STR))
        debug_print('jit_debug:', hlstr(msg),
                    arg1box.getint(), arg2box.getint(),
                    arg3box.getint(), arg4box.getint())
        args = [stringbox, arg1box, arg2box, arg3box, arg4box]
        i = 4
        while i > 0 and args[i].getint() == -sys.maxint-1:
            i -= 1
        assert i >= 0
        op = self.metainterp.history.record(rop.JIT_DEBUG, args[:i+1], None)
        self.metainterp.attach_debug_info(op)

    @arguments("box")
    def _opimpl_assert_green(self, b…