SPECjvm2008-SOR.small innermost loop is not vectorizable but it still has extra unrolling depending on MaxVectorSize setting. Superword unroll analysis does not identify that the loop is not vectorizable.
Please note that there is true dependency in the innermost loop so it cannot be vectorized.
  
for (int p=0; p<num_iterations; p++) {
            for (int i=1; i<Mm1; i++) {
                Gi = G[i];
                double[] Gim1 = G[i-1];
                double[] Gip1 = G[i+1];
                for (int j=1; j<Nm1; j++)
                    Gi[j] = omega_over_four * (Gim1[j] + Gip1[j] + Gi[j-1]
                            + Gi[j+1]) + one_minus_omega * Gi[j];
            }
  }

In the above code snippet their is true dependency as Gi[j] depends on Gi[j-1] and so the loop cannot be vectorized.