

    @param[in]
    nb      INTEGER
            The number of columns to be reduced.

    @param[in,out]
    dA      COMPLEX_16 array on the GPU, dimension (LDDA,N-K+1)
            On entry, the n-by-(n-k+1) general matrix A.
            On exit, the elements in rows K:N of the first NB columns are
            overwritten with the matrix Y.

    @param[in]
    ldda    INTEGER
            The leading dimension of the array dA.  LDDA >= max(1,N).

    @param[out]
    dV      COMPLEX_16 array on the GPU, dime