Thread: keeping values in cache

Is there a way to explicit tell the compiler to keep a value in the cache for the whole loop? Like

Code:

for (j=0; j<MAX; j++)
   for (i=0; i<MAX; i++)
      y[j] += a[i] * b[i]

...and tell the compiler to keep the value y[i] for the whole inner loop, gaining optimization. I know it is possible, but i don't know how or if the compiler would do this anyway.