优化代码void can_app_sig_rx_vehicle_speed_polling(void) { U16 speed = 0; U8 speed_ret = can_app_il_get_rx_ESP_v_Signal_1(&speed); U8 speed_valid=0; can_app_il_get_rx_ESP_QBit_v_Signal(&speed_valid); U8 speed_timeout = ((speed_ret&CAN_IL_TIMEOUT)!=CAN_IL_TIMEOUT)?FALSE:TRUE; static U8 speed_timeout_bk = 0; static BOOL speed_update_flag = FALSE; if(speed_timeout_bk != speed_timeout) { if(speed_timeout) { can_sig_vehicle_speed_valid = 1; can_app_output_vehicle_speed(); can_sig_vehicle_speed_valid = speed_valid; } else//when timeout change to normal,need send it. { speed_update_flag = TRUE; } speed_timeout_bk = speed_timeout; } if((can_sig_vehicle_speed != speed)||(can_sig_vehicle_speed_valid != speed_valid)||speed_update_flag) { can_sig_vehicle_speed = speed; can_sig_vehicle_speed_valid = speed_valid; speed_update_flag = FALSE; can_app_output_vehicle_speed(); } }

可以尝试使用以下优化方式：

1. 减少函数调用次数。可以将 `can_app_il_get_rx_ESP_v_Signal_1` 和 `can_app_il_get_rx_ESP_QBit_v_Signal` 的返回值存储在局部变量中，避免多次调用。

2. 避免过多的变量复制。可以直接将 `speed_ret&CAN_IL_TIMEOUT` 的结果赋值给 `speed_timeout`，避免中间变量的使用。

3. 尽可能减少全局变量的使用。可以将 `can_sig_vehicle_speed` 和 `can_sig_vehicle_speed_valid` 作为参数传递给 `can_app_output_vehicle_speed` 函数，避免全局变量的使用。

4. 将静态变量的初始化移动到函数外部，避免每次函数调用都进行初始化。

下面是优化后的代码示例：

void can_app_sig_rx_vehicle_speed_polling(U16 *vehicle_speed, U8 *vehicle_speed_valid) {
    U16 speed = 0;
    U8 speed_ret = 0;
    U8 speed_valid = 0;
    static U8 speed_timeout_bk = 0;
    static BOOL speed_update_flag = FALSE;
    static BOOL speed_timeout = FALSE;

    speed_ret = can_app_il_get_rx_ESP_v_Signal_1(&speed);
    can_app_il_get_rx_ESP_QBit_v_Signal(&speed_valid);
    speed_timeout = (speed_ret & CAN_IL_TIMEOUT) ? TRUE : FALSE;

    if (speed_timeout_bk != speed_timeout) {
        if (speed_timeout) {
            *vehicle_speed_valid = 1;
            speed_update_flag = TRUE;
        }
        speed_timeout_bk = speed_timeout;
    }

    if (*vehicle_speed != speed || *vehicle_speed_valid != speed_valid || speed_update_flag) {
        *vehicle_speed = speed;
        *vehicle_speed_valid = speed_valid;
        can_app_output_vehicle_speed(*vehicle_speed, *vehicle_speed_valid);
        speed_update_flag = FALSE;
    }
}