Is there any performance difference between accessing a hardcode array and a run time initialization array?

For example, I want to create a square root table using array SQRT[i] to optimize a game, but I don't know if there is performance difference between the following initialization when accessing the value of SQRT[i]:

1. Hardcode array

   int SQRT[]={0,1,1,1,2,2,2,2,2,3,3,.......255,255,255}
   
   

2. Generate value at run time

   int SQRT[65536];
   int main(){
       for(int i=0;i<65536;i++){
           SQRT[i]=sqrt(i);
       }
       //other code
       return 0;
   }
   
   

Some example of accessing them:

    if(SQRT[a*a+b*b]>something)
    ...

At start, I thought they should be the same, but I don't know if the program stores or access a hard-code array in different way. Also, I don't know if compiler will optimize the hard-code array to speed up the access time, is there performance difference between them when accessing the array?

via Chebli Mohamed