数组与联合数组的联合是否会产生相同的代码W.R.T时间来进行读写操作？

大家好，我想知道这2个定义是否会产生相同的代码W.R.T时间来对它们进行读写操作？我的意思是，这两种结构的汇编指令都是不同的，但在时间尺度上，哪一种更有效，而对它们进行数据读写操作呢？非常感谢您的帮助。



      以下为原文

    Hello everyone
I wonder if these 2 definitions would produce same code w.r.t time it takes to do read write operations on them? I mean that the assembly instructions for both constructs would be different but on the time scale which one of these would be more efficient while data read write operations are carried out on them?

union
{
    unsigned int LUT[256];
    struct
    {
        unsigned char LUT_L;
        unsigned char LUT_H;
    }s_LUT[256];
   
}u_LUT;

Or

union
{
    unsigned int LUT;
    struct
    {
        unsigned char LUT_L;
        unsigned char LUT_H;
    }s_LUT;
   
}u_LUT[256];

Your help is highly appreciated.