DLASDT creates a tree of subproblems for bidiagonal divide and
 conquer.

          N is INTEGER
          On entry, the number of diagonal elements of the
          bidiagonal matrix.

          LVL is INTEGER
          On exit, the number of levels on the computation tree.

          ND is INTEGER
          On exit, the number of nodes on the tree.

          INODE is INTEGER array, dimension ( N )
          On exit, centers of subproblems.

          NDIML is INTEGER array, dimension ( N )
          On exit, row dimensions of left children.

          NDIMR is INTEGER array, dimension ( N )
          On exit, row dimensions of right children.

          MSUB is INTEGER
          On entry, the maximum row dimension each subproblem at the
          bottom of the tree can be of.