s well as of the corresponding 1-by-1 or
          2-by-2 diagonal blocks of the factors in the array A.
          The 2-by-2 blocks correspond to negative values in IWORK.
          One negative value is stored for each such eigenvalue
          pair. Its modulus indicates the starting index of a
          2-by-2 block. This is also done for any value of IWARN,
          if a 2-by-2 block is found to have two real eigenvalues.
          On exit, if INFO = -22, IWORK(1) returns the minimum value
          o