op (_GUARD_IS_NONE_POP, (val -- )) {
            int is_none = PyStackRef_IsNone(val);
            if (!is_none) {
                PyStackRef_CLOSE(val);
                AT_END_EXIT_IF(1);
            }
            DEAD(val);
        }

        op (_GUARD_IS_NONE_POP, (val -- )) {
            int is_none = PyStackRef_IsNone(val);
            if (!is_none) {
                goto _GUARD_IS_NONE_POP_COLD; // tail call
            }
            DEAD(val);
        }

        op (_GUARD_IS_NONE_POP_COLD, (val -- )) {
            PyStackRef_CLOSE(val);
            AT_END_EXIT_IF(1);
        }

        op (_GUARD_IS_NONE_POP, (val -- )) {
            int is_none = PyStackRef_IsNone(val);
            if (!is_none) {
                EXIT_TO(POP_TOP_EXIT);
            }
            DEAD(val);
        }

        exit op (POP_TOP_EXIT, (val -- )) {
            PyStackRef_CLOSE(val);
        }

    tier2 op(_ITER_NEXT_INLINE, (iternext_fn/4, iter, null_or_index -- iter, null_or_index, next)) {
        assert(sizeof(iternextfunc) == sizeof(uintptr_t));
        volatile iternextfunc iternext_v = (iternextfunc)iternext_fn;
        PyObject *item = iternext_v(PyStackRef_AsPyObjectBorrow(iter));
        if (item == NULL) {
            EXIT_TO(_ITER_NEXT_INLINE_EXIT);
        }
        STAT_INC(FOR_ITER, hit);
        next = PyStackRef_FromPyObjectSteal(item);
    }

    exit op(_ITER_NEXT_INLINE_EXIT, ( -- )) {
        if (_PyErr_Occurred(tstate)) {
            if (_PyErr_ExceptionMatches(tstate, PyExc_StopIteration)) {
                _PyEval_MonitorRaise(tstate, frame, frame->instr_ptr);
                _PyErr_Clear(tstate);
            }
            else {
                ERROR_NO_POP();
            }
        }
   }