void emulate_Conv_U8(Instruction instr)
        {
            var val1 = valueStack.pop();

            switch (val1.valueType)
            {
            case ValueType.Int32:   valueStack.push(Int64Value.Conv_U8((Int32Value)val1)); break;

            case ValueType.Int64:   valueStack.push(Int64Value.Conv_U8((Int64Value)val1)); break;

            case ValueType.Real8:   valueStack.push(Int64Value.Conv_U8((Real8Value)val1)); break;

            default:                                valueStack.push(Int64Value.createUnknown()); break;
            }
        }