          SUBROUTINE CGEGS( JOBVSL, JOBVSR, N, A, LDA, B, LDB, ALPHA, BETA,
         $                  VSL, LDVSL, VSR, LDVSR, WORK, LWORK, RWORK,
         $                  INFO )
    *
    *  -- LAPACK driver routine (version 3.1) --
    *     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
    *     November 2006
    *
    *     .. Scalar Arguments ..
          CHARACTER          JOBVSL, JOBVSR
          INTEGER            INFO, LDA, LDB, LDVSL, LDVSR, LWORK, N
    *     ..
    *     .. Array Arguments ..
          REAL               RWORK( * )
          COMPLEX            A( LDA, * ), ALPHA( * ), B( LDB, * ),
         $                   BETA( * ), VSL( LDVSL, * ), VSR( LDVSR, * ),
         $                   WORK( * )
    *     ..
    *
    *  Purpose
    *  =======
    *
    *  This routine is deprecated and has been replaced by routine CGGES.
    *
    *  CGEGS computes the eigenvalues, Schur form, and, optionally, the
    *  left and or/right Schur vectors of a complex matrix pair (A,B).
    *  Given two square matrices A and B, the generalized Schur
    *  factorization has the form
    *
    *     A = Q*S*Z**H,  B = Q*T*Z**H
    *
    *  where Q and Z are unitary matrices and S and T are upper triangular.
    *  The columns of Q are the left Schur vectors
    *  and the columns of Z are the right Schur vectors.
    *
    *  If only the eigenvalues of (A,B) are needed, the driver routine
    *  CGEGV should be used instead.  See CGEGV for a description of the
    *  eigenvalues of the generalized nonsymmetric eigenvalue problem
    *  (GNEP).
    *
    *  Arguments
    *  =========
    *
    *  JOBVSL   (input) CHARACTER*1
    *          = 'N':  do not compute the left Schur vectors;
    *          = 'V':  compute the left Schur vectors (returned in VSL).
    *
    *  JOBVSR   (input) CHARACTER*1
    *          = 'N':  do not compute the right Schur vectors;
    *          = 'V':  compute the right Schur vectors (returned in VSR).
    *
    *  N       (input) INTEGER
    *          The order of the matrices A, B, VSL, and VSR.  N >= 0.
    *
    *  A       (input/output) COMPLEX array, dimension (LDA, N)
    *          On entry, the matrix A.
    *          On exit, the upper triangular matrix S from the generalized
    *          Schur factorization.
    *
    *  LDA     (input) INTEGER
    *          The leading dimension of A.  LDA >= max(1,N).
    *
    *  B       (input/output) COMPLEX array, dimension (LDB, N)
    *          On entry, the matrix B.
    *          On exit, the upper triangular matrix T from the generalized
    *          Schur factorization.
    *
    *  LDB     (input) INTEGER
    *          The leading dimension of B.  LDB >= max(1,N).
    *
    *  ALPHA   (output) COMPLEX array, dimension (N)
    *          The complex scalars alpha that define the eigenvalues of
    *          GNEP.  ALPHA(j) = S(j,j), the diagonal element of the Schur
    *          form of A.
    *
    *  BETA    (output) COMPLEX array, dimension (N)
    *          The non-negative real scalars beta that define the
    *          eigenvalues of GNEP.  BETA(j) = T(j,j), the diagonal element
    *          of the triangular factor T.
    *
    *          Together, the quantities alpha = ALPHA(j) and beta = BETA(j)
    *          represent the j-th eigenvalue of the matrix pair (A,B), in
    *          one of the forms lambda = alpha/beta or mu = beta/alpha.
    *          Since either lambda or mu may overflow, they should not,
    *          in general, be computed.
    *
    *  VSL     (output) COMPLEX array, dimension (LDVSL,N)
    *          If JOBVSL = 'V', the matrix of left Schur vectors Q.
    *          Not referenced if JOBVSL = 'N'.
    *
    *  LDVSL   (input) INTEGER
    *          The leading dimension of the matrix VSL. LDVSL >= 1, and
    *          if JOBVSL = 'V', LDVSL >= N.
    *
    *  VSR     (output) COMPLEX array, dimension (LDVSR,N)
    *          If JOBVSR = 'V', the matrix of right Schur vectors Z.
    *          Not referenced if JOBVSR = 'N'.
    *
    *  LDVSR   (input) INTEGER
    *          The leading dimension of the matrix VSR. LDVSR >= 1, and
    *          if JOBVSR = 'V', LDVSR >= N.
    *
    *  WORK    (workspace/output) COMPLEX array, dimension (MAX(1,LWORK))
    *          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
    *
    *  LWORK   (input) INTEGER
    *          The dimension of the array WORK.  LWORK >= max(1,2*N).
    *          For good performance, LWORK must generally be larger.
    *          To compute the optimal value of LWORK, call ILAENV to get
    *          blocksizes (for CGEQRF, CUNMQR, and CUNGQR.)  Then compute:
    *          NB  -- MAX of the blocksizes for CGEQRF, CUNMQR, and CUNGQR;
    *          the optimal LWORK is N*(NB+1).
    *
    *          If LWORK = -1, then a workspace query is assumed; the routine
    *          only calculates the optimal size of the WORK array, returns
    *          this value as the first entry of the WORK array, and no error
    *          message related to LWORK is issued by XERBLA.
    *
    *  RWORK   (workspace) REAL array, dimension (3*N)
    *
    *  INFO    (output) INTEGER
    *          = 0:  successful exit
    *          < 0:  if INFO = -i, the i-th argument had an illegal value.
    *          =1,...,N:
    *                The QZ iteration failed.  (A,B) are not in Schur
    *                form, but ALPHA(j) and BETA(j) should be correct for
    *                j=INFO+1,...,N.
    *          > N:  errors that usually indicate LAPACK problems:
    *                =N+1: error return from CGGBAL
    *                =N+2: error return from CGEQRF
    *                =N+3: error return from CUNMQR
    *                =N+4: error return from CUNGQR
    *                =N+5: error return from CGGHRD
    *                =N+6: error return from CHGEQZ (other than failed
    *                                               iteration)
    *                =N+7: error return from CGGBAK (computing VSL)
    *                =N+8: error return from CGGBAK (computing VSR)
    *                =N+9: error return from CLASCL (various places)
    *
    *  =====================================================================
    *
    *     .. Parameters ..
          REAL               ZERO, ONE
          PARAMETER          ( ZERO = 0.0E0, ONE = 1.0E0 )
          COMPLEX            CZERO, CONE
          PARAMETER          ( CZERO = ( 0.0E0, 0.0E0 ),
         $                   CONE = ( 1.0E0, 0.0E0 ) )
    *     ..
    *     .. Local Scalars ..
          LOGICAL            ILASCL, ILBSCL, ILVSL, ILVSR, LQUERY
          INTEGER            ICOLS, IHI, IINFO, IJOBVL, IJOBVR, ILEFT,
         $                   ILO, IRIGHT, IROWS, IRWORK, ITAU, IWORK,
         $                   LOPT, LWKMIN, LWKOPT, NB, NB1, NB2, NB3
          REAL               ANRM, ANRMTO, BIGNUM, BNRM, BNRMTO, EPS,
         $                   SAFMIN, SMLNUM
    *     ..
    *     .. External Subroutines ..
          EXTERNAL           CGEQRF, CGGBAK, CGGBAL, CGGHRD, CHGEQZ, CLACPY,
         $                   CLASCL, CLASET, CUNGQR, CUNMQR, XERBLA
    *     ..
    *     .. External Functions ..
          LOGICAL            LSAME
          INTEGER            ILAENV
          REAL               CLANGE, SLAMCH
          EXTERNAL           ILAENV, LSAME, CLANGE, SLAMCH
    *     ..
    *     .. Intrinsic Functions ..
          INTRINSIC          INT, MAX
    *     ..
    *     .. Executable Statements ..
    *
    *     Decode the input arguments
    *
          IF( LSAME( JOBVSL, 'N' ) ) THEN
             IJOBVL = 1
             ILVSL = .FALSE.
          ELSE IF( LSAME( JOBVSL, 'V' ) ) THEN
             IJOBVL = 2
             ILVSL = .TRUE.
          ELSE
             IJOBVL = -1
             ILVSL = .FALSE.
          END IF
    *
          IF( LSAME( JOBVSR, 'N' ) ) THEN
             IJOBVR = 1
             ILVSR = .FALSE.
          ELSE IF( LSAME( JOBVSR, 'V' ) ) THEN
             IJOBVR = 2
             ILVSR = .TRUE.
          ELSE
             IJOBVR = -1
             ILVSR = .FALSE.
          END IF
    *
    *     Test the input arguments
    *
          LWKMIN = MAX( 2*N, 1 )
          LWKOPT = LWKMIN
          WORK( 1 ) = LWKOPT
          LQUERY = ( LWORK.EQ.-1 )
          INFO = 0
          IF( IJOBVL.LE.0 ) THEN
             INFO = -1
          ELSE IF( IJOBVR.LE.0 ) THEN
             INFO = -2
          ELSE IF( N.LT.0 ) THEN
             INFO = -3
          ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
             INFO = -5
          ELSE IF( LDB.LT.MAX( 1, N ) ) THEN
             INFO = -7
          ELSE IF( LDVSL.LT.1 .OR. ( ILVSL .AND. LDVSL.LT.N ) ) THEN
             INFO = -11
          ELSE IF( LDVSR.LT.1 .OR. ( ILVSR .AND. LDVSR.LT.N ) ) THEN
             INFO = -13
          ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
             INFO = -15
          END IF
    *
          IF( INFO.EQ.0 ) THEN
             NB1 = ILAENV( 1, 'CGEQRF', ' ', N, N, -1, -1 )
             NB2 = ILAENV( 1, 'CUNMQR', ' ', N, N, N, -1 )
             NB3 = ILAENV( 1, 'CUNGQR', ' ', N, N, N, -1 )
             NB = MAX( NB1, NB2, NB3 )
             LOPT = N*(NB+1)
             WORK( 1 ) = LOPT
          END IF
    *
          IF( INFO.NE.0 ) THEN
             CALL XERBLA( 'CGEGS ', -INFO )
             RETURN
          ELSE IF( LQUERY ) THEN
             RETURN
          END IF
    *
    *     Quick return if possible
    *
          IF( N.EQ.0 )
         $   RETURN
    *
    *     Get machine constants
    *
          EPS = SLAMCH( 'E' )*SLAMCH( 'B' )
          SAFMIN = SLAMCH( 'S' )
          SMLNUM = N*SAFMIN / EPS
          BIGNUM = ONE / SMLNUM
    *
    *     Scale A if max element outside range [SMLNUM,BIGNUM]
    *
          ANRM = CLANGE( 'M', N, N, A, LDA, RWORK )
          ILASCL = .FALSE.
          IF( ANRM.GT.ZERO .AND. ANRM.LT.SMLNUM ) THEN
             ANRMTO = SMLNUM
             ILASCL = .TRUE.
          ELSE IF( ANRM.GT.BIGNUM ) THEN
             ANRMTO = BIGNUM
             ILASCL = .TRUE.
          END IF
    *
          IF( ILASCL ) THEN
             CALL CLASCL( 'G', -1, -1, ANRM, ANRMTO, N, N, A, LDA, IINFO )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 9
                RETURN
             END IF
          END IF
    *
    *     Scale B if max element outside range [SMLNUM,BIGNUM]
    *
          BNRM = CLANGE( 'M', N, N, B, LDB, RWORK )
          ILBSCL = .FALSE.
          IF( BNRM.GT.ZERO .AND. BNRM.LT.SMLNUM ) THEN
             BNRMTO = SMLNUM
             ILBSCL = .TRUE.
          ELSE IF( BNRM.GT.BIGNUM ) THEN
             BNRMTO = BIGNUM
             ILBSCL = .TRUE.
          END IF
    *
          IF( ILBSCL ) THEN
             CALL CLASCL( 'G', -1, -1, BNRM, BNRMTO, N, N, B, LDB, IINFO )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 9
                RETURN
             END IF
          END IF
    *
    *     Permute the matrix to make it more nearly triangular
    *
          ILEFT = 1
          IRIGHT = N + 1
          IRWORK = IRIGHT + N
          IWORK = 1
          CALL CGGBAL( 'P', N, A, LDA, B, LDB, ILO, IHI, RWORK( ILEFT ),
         $             RWORK( IRIGHT ), RWORK( IRWORK ), IINFO )
          IF( IINFO.NE.0 ) THEN
             INFO = N + 1
             GO TO 10
          END IF
    *
    *     Reduce B to triangular form, and initialize VSL and/or VSR
    *
          IROWS = IHI + 1 - ILO
          ICOLS = N + 1 - ILO
          ITAU = IWORK
          IWORK = ITAU + IROWS
          CALL CGEQRF( IROWS, ICOLS, B( ILO, ILO ), LDB, WORK( ITAU ),
         $             WORK( IWORK ), LWORK+1-IWORK, IINFO )
          IF( IINFO.GE.0 )
         $   LWKOPT = MAX( LWKOPT, INT( WORK( IWORK ) )+IWORK-1 )
          IF( IINFO.NE.0 ) THEN
             INFO = N + 2
             GO TO 10
          END IF
    *
          CALL CUNMQR( 'L', 'C', IROWS, ICOLS, IROWS, B( ILO, ILO ), LDB,
         $             WORK( ITAU ), A( ILO, ILO ), LDA, WORK( IWORK ),
         $             LWORK+1-IWORK, IINFO )
          IF( IINFO.GE.0 )
         $   LWKOPT = MAX( LWKOPT, INT( WORK( IWORK ) )+IWORK-1 )
          IF( IINFO.NE.0 ) THEN
             INFO = N + 3
             GO TO 10
          END IF
    *
          IF( ILVSL ) THEN
             CALL CLASET( 'Full', N, N, CZERO, CONE, VSL, LDVSL )
             CALL CLACPY( 'L', IROWS-1, IROWS-1, B( ILO+1, ILO ), LDB,
         $                VSL( ILO+1, ILO ), LDVSL )
             CALL CUNGQR( IROWS, IROWS, IROWS, VSL( ILO, ILO ), LDVSL,
         $                WORK( ITAU ), WORK( IWORK ), LWORK+1-IWORK,
         $                IINFO )
             IF( IINFO.GE.0 )
         $      LWKOPT = MAX( LWKOPT, INT( WORK( IWORK ) )+IWORK-1 )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 4
                GO TO 10
             END IF
          END IF
    *
          IF( ILVSR )
         $   CALL CLASET( 'Full', N, N, CZERO, CONE, VSR, LDVSR )
    *
    *     Reduce to generalized Hessenberg form
    *
          CALL CGGHRD( JOBVSL, JOBVSR, N, ILO, IHI, A, LDA, B, LDB, VSL,
         $             LDVSL, VSR, LDVSR, IINFO )
          IF( IINFO.NE.0 ) THEN
             INFO = N + 5
             GO TO 10
          END IF
    *
    *     Perform QZ algorithm, computing Schur vectors if desired
    *
          IWORK = ITAU
          CALL CHGEQZ( 'S', JOBVSL, JOBVSR, N, ILO, IHI, A, LDA, B, LDB,
         $             ALPHA, BETA, VSL, LDVSL, VSR, LDVSR, WORK( IWORK ),
         $             LWORK+1-IWORK, RWORK( IRWORK ), IINFO )
          IF( IINFO.GE.0 )
         $   LWKOPT = MAX( LWKOPT, INT( WORK( IWORK ) )+IWORK-1 )
          IF( IINFO.NE.0 ) THEN
             IF( IINFO.GT.0 .AND. IINFO.LE.N ) THEN
                INFO = IINFO
             ELSE IF( IINFO.GT.N .AND. IINFO.LE.2*N ) THEN
                INFO = IINFO - N
             ELSE
                INFO = N + 6
             END IF
             GO TO 10
          END IF
    *
    *     Apply permutation to VSL and VSR
    *
          IF( ILVSL ) THEN
             CALL CGGBAK( 'P', 'L', N, ILO, IHI, RWORK( ILEFT ),
         $                RWORK( IRIGHT ), N, VSL, LDVSL, IINFO )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 7
                GO TO 10
             END IF
          END IF
          IF( ILVSR ) THEN
             CALL CGGBAK( 'P', 'R', N, ILO, IHI, RWORK( ILEFT ),
         $                RWORK( IRIGHT ), N, VSR, LDVSR, IINFO )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 8
                GO TO 10
             END IF
          END IF
    *
    *     Undo scaling
    *
          IF( ILASCL ) THEN
             CALL CLASCL( 'U', -1, -1, ANRMTO, ANRM, N, N, A, LDA, IINFO )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 9
                RETURN
             END IF
             CALL CLASCL( 'G', -1, -1, ANRMTO, ANRM, N, 1, ALPHA, N, IINFO )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 9
                RETURN
             END IF
          END IF
    *
          IF( ILBSCL ) THEN
             CALL CLASCL( 'U', -1, -1, BNRMTO, BNRM, N, N, B, LDB, IINFO )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 9
                RETURN
             END IF
             CALL CLASCL( 'G', -1, -1, BNRMTO, BNRM, N, 1, BETA, N, IINFO )
             IF( IINFO.NE.0 ) THEN
                INFO = N + 9
                RETURN
             END IF
          END IF
    *
       10 CONTINUE
          WORK( 1 ) = LWKOPT
    *
          RETURN
    *
    *     End of CGEGS
    *
          END