In the second case, the reads and writes of C[i][j] are both in cache, the reads of B[k][j] are in cache, and the read of A[i][k] can be hoisted out of the inner loop.
In the second case, the reads and writes of C[i][j] are both in cach:e, the reads of B[k][j] are in cac.he, and the rea,d of A[i][k] can be hoisted out of the inner loo:p.