我让chatGPT帮我优化代码，跟我想的一样

1万 · 2023-3-2 08:50

以下代码出自CH32V103的库函数，此函数为实现5个不同分支的if elseif else 结构的判断工作，由于判断对象都是常量，因此我认为可以使用switch case 优化这些操作，以便看着更加简洁清爽。
于是我让chatGPT帮我完成这个事情。
我的提问截图

原始内容

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void NVIC_Init(NVIC_InitTypeDef *NVIC_InitStruct)

{

    uint8_t tmppre = 0;



    if(NVIC_Priority_Group == NVIC_PriorityGroup_0)

    {

        NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, NVIC_InitStruct->NVIC_IRQChannelSubPriority << 4);

    }

    else if(NVIC_Priority_Group == NVIC_PriorityGroup_1)

    {

        if(NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority == 1)

        {

            NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, (1 << 7) | (NVIC_InitStruct->NVIC_IRQChannelSubPriority << 4));

        }

        else

        {

            NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, (0 << 7) | (NVIC_InitStruct->NVIC_IRQChannelSubPriority << 4));

        }

    }

    else if(NVIC_Priority_Group == NVIC_PriorityGroup_2)

    {

        if(NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority <= 1)

        {

            tmppre = NVIC_InitStruct->NVIC_IRQChannelSubPriority + (4 * NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority);

            NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, (0 << 7) | (tmppre << 4));

        }

        else

        {

            tmppre = NVIC_InitStruct->NVIC_IRQChannelSubPriority + (4 * (NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority - 2));

            NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, (1 << 7) | (tmppre << 4));

        }

    }

    else if(NVIC_Priority_Group == NVIC_PriorityGroup_3)

    {

        if(NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority <= 3)

        {

            tmppre = NVIC_InitStruct->NVIC_IRQChannelSubPriority + (2 * NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority);

            NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, (0 << 7) | (tmppre << 4));

        }

        else

        {

            tmppre = NVIC_InitStruct->NVIC_IRQChannelSubPriority + (2 * (NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority - 4));

            NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, (1 << 7) | (tmppre << 4));

        }

    }

    else if(NVIC_Priority_Group == NVIC_PriorityGroup_4)

    {

        NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority << 4);

    }



    if(NVIC_InitStruct->NVIC_IRQChannelCmd != DISABLE)

    {

        NVIC_EnableIRQ(NVIC_InitStruct->NVIC_IRQChannel);

    }

    else

    {

        NVIC_DisableIRQ(NVIC_InitStruct->NVIC_IRQChannel);

    }

}

chatGPT优化后的

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void NVIC_Init(NVIC_InitTypeDef *NVIC_InitStruct)

{

    uint8_t tmppre = 0;

    

    switch(NVIC_Priority_Group)

    {

        case NVIC_PriorityGroup_0:

            NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, 

                   NVIC_InitStruct->NVIC_IRQChannelSubPriority << 4);

            break;

        case NVIC_PriorityGroup_1:

            if(NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority == 1)

                NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, 

                        (1 << 7) | 

                        (NVIC_InitStruct->NVIC_IRQChannelSubPriority << 4));

            else

                NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, 

                        (0 << 7) | 

                        (NVIC_InitStruct->NVIC_IRQChannelSubPriority << 4));

            break;

        case NVIC_PriorityGroup_2:

            if(NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority <= 1)

            {

                tmppre = NVIC_InitStruct->NVIC_IRQChannelSubPriority +

                      (4 * NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority);

                NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, 

                        (0 << 7) | (tmppre << 4));

            }

            else

            {

                tmppre = NVIC_InitStruct->NVIC_IRQChannelSubPriority + 

                       (4 * (NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority - 2));

                NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, 

                        (1 << 7) | (tmppre << 4));

            }

            break;

        case NVIC_PriorityGroup_3:

            if(NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority <= 3)

            {

                tmppre = NVIC_InitStruct->NVIC_IRQChannelSubPriority + 

                       (2 * NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority);

                NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, 

                        (0 << 7) | (tmppre << 4));

            }

            else

            {

                tmppre = NVIC_InitStruct->NVIC_IRQChannelSubPriority + 

                       (2 * (NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority - 4));

                NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, 

                        (1 << 7) | (tmppre << 4));

            }

            break;

        case NVIC_PriorityGroup_4:

            NVIC_SetPriority(NVIC_InitStruct->NVIC_IRQChannel, 

                    NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority << 4);

            break; 

    }

    

    if(NVIC_InitStruct->NVIC_IRQChannelCmd != DISABLE)

        NVIC_EnableIRQ(NVIC_InitStruct->NVIC_IRQChannel);

    else

        NVIC_DisableIRQ(NVIC_InitStruct->NVIC_IRQChannel);

}