#include "blaswrap.h"
#include "f2c.h"

/* Subroutine */ int dgges_(char *jobvsl, char *jobvsr, char *sort, L_fp 
	delctg, integer *n, doublereal *a, integer *lda, doublereal *b, 
	integer *ldb, integer *sdim, doublereal *alphar, doublereal *alphai, 
	doublereal *beta, doublereal *vsl, integer *ldvsl, doublereal *vsr, 
	integer *ldvsr, doublereal *work, integer *lwork, logical *bwork, 
	integer *info)
{
/*  -- LAPACK driver routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       June 30, 1999   


    Purpose   
    =======   

    DGGES computes for a pair of N-by-N real nonsymmetric matrices (A,B),   
    the generalized eigenvalues, the generalized real Schur form (S,T),   
    optionally, the left and/or right matrices of Schur vectors (VSL and   
    VSR). This gives the generalized Schur factorization   

             (A,B) = ( (VSL)*S*(VSR)**T, (VSL)*T*(VSR)**T )   

    Optionally, it also orders the eigenvalues so that a selected cluster   
    of eigenvalues appears in the leading diagonal blocks of the upper   
    quasi-triangular matrix S and the upper triangular matrix T.The   
    leading columns of VSL and VSR then form an orthonormal basis for the   
    corresponding left and right eigenspaces (deflating subspaces).   

    (If only the generalized eigenvalues are needed, use the driver   
    DGGEV instead, which is faster.)   

    A generalized eigenvalue for a pair of matrices (A,B) is a scalar w   
    or a ratio alpha/beta = w, such that  A - w*B is singular.  It is   
    usually represented as the pair (alpha,beta), as there is a   
    reasonable interpretation for beta=0 or both being zero.   

    A pair of matrices (S,T) is in generalized real Schur form if T is   
    upper triangular with non-negative diagonal and S is block upper   
    triangular with 1-by-1 and 2-by-2 blocks.  1-by-1 blocks correspond   
    to real generalized eigenvalues, while 2-by-2 blocks of S will be   
    "standardized" by making the corresponding elements of T have the   
    form:   
            [  a  0  ]   
            [  0  b  ]   

    and the pair of corresponding 2-by-2 blocks in S and T will have a   
    complex conjugate pair of generalized eigenvalues.   


    Arguments   
    =========   

    JOBVSL  (input) CHARACTER*1   
            = 'N':  do not compute the left Schur vectors;   
            = 'V':  compute the left Schur vectors.   

    JOBVSR  (input) CHARACTER*1   
            = 'N':  do not compute the right Schur vectors;   
            = 'V':  compute the right Schur vectors.   

    SORT    (input) CHARACTER*1   
            Specifies whether or not to order the eigenvalues on the   
            diagonal of the generalized Schur form.   
            = 'N':  Eigenvalues are not ordered;   
            = 'S':  Eigenvalues are ordered (see DELZTG);   

    DELZTG  (input) LOGICAL FUNCTION of three DOUBLE PRECISION arguments   
            DELZTG must be declared EXTERNAL in the calling subroutine.   
            If SORT = 'N', DELZTG is not referenced.   
            If SORT = 'S', DELZTG is used to select eigenvalues to sort   
            to the top left of the Schur form.   
            An eigenvalue (ALPHAR(j)+ALPHAI(j))/BETA(j) is selected if   
            DELZTG(ALPHAR(j),ALPHAI(j),BETA(j)) is true; i.e. if either   
            one of a complex conjugate pair of eigenvalues is selected,   
            then both complex eigenvalues are selected.   

            Note that in the ill-conditioned case, a selected complex   
            eigenvalue may no longer satisfy DELZTG(ALPHAR(j),ALPHAI(j),   
            BETA(j)) = .TRUE. after ordering. INFO is to be set to N+2   
            in this case.   

    N       (input) INTEGER   
            The order of the matrices A, B, VSL, and VSR.  N >= 0.   

    A       (input/output) DOUBLE PRECISION array, dimension (LDA, N)   
            On entry, the first of the pair of matrices.   
            On exit, A has been overwritten by its generalized Schur   
            form S.   

    LDA     (input) INTEGER   
            The leading dimension of A.  LDA >= max(1,N).   

    B       (input/output) DOUBLE PRECISION array, dimension (LDB, N)   
            On entry, the second of the pair of matrices.   
            On exit, B has been overwritten by its generalized Schur   
            form T.   

    LDB     (input) INTEGER   
            The leading dimension of B.  LDB >= max(1,N).   

    SDIM    (output) INTEGER   
            If SORT = 'N', SDIM = 0.   
            If SORT = 'S', SDIM = number of eigenvalues (after sorting)   
            for which DELZTG is true.  (Complex conjugate pairs for which   
            DELZTG is true for either eigenvalue count as 2.)   

    ALPHAR  (output) DOUBLE PRECISION array, dimension (N)   
    ALPHAI  (output) DOUBLE PRECISION array, dimension (N)   
    BETA    (output) DOUBLE PRECISION array, dimension (N)   
            On exit, (ALPHAR(j) + ALPHAI(j)*i)/BETA(j), j=1,...,N, will   
            be the generalized eigenvalues.  ALPHAR(j) + ALPHAI(j)*i,   
            and  BETA(j),j=1,...,N are the diagonals of the complex Schur   
            form (S,T) that would result if the 2-by-2 diagonal blocks of   
            the real Schur form of (A,B) were further reduced to   
            triangular form using 2-by-2 complex unitary transformations.   
            If ALPHAI(j) is zero, then the j-th eigenvalue is real; if   
            positive, then the j-th and (j+1)-st eigenvalues are a   
            complex conjugate pair, with ALPHAI(j+1) negative.   

            Note: the quotients ALPHAR(j)/BETA(j) and ALPHAI(j)/BETA(j)   
            may easily over- or underflow, and BETA(j) may even be zero.   
            Thus, the user should avoid naively computing the ratio.   
            However, ALPHAR and ALPHAI will be always less than and   
            usually comparable with norm(A) in magnitude, and BETA always   
            less than and usually comparable with norm(B).   

    VSL     (output) DOUBLE PRECISION array, dimension (LDVSL,N)   
            If JOBVSL = 'V', VSL will contain the left Schur vectors.   
            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) DOUBLE PRECISION array, dimension (LDVSR,N)   
            If JOBVSR = 'V', VSR will contain the right Schur vectors.   
            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) DOUBLE PRECISION array, dimension (LWORK)   
            On exit, if INFO = 0, WORK(1) returns the optimal LWORK.   

    LWORK   (input) INTEGER   
            The dimension of the array WORK.  LWORK >= 8*N+16.   

            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.   

    BWORK   (workspace) LOGICAL array, dimension (N)   
            Not referenced if SORT = '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 ALPHAR(j), ALPHAI(j), and BETA(j) should   
                  be correct for j=INFO+1,...,N.   
            > N:  =N+1: other than QZ iteration failed in DHGEQZ.   
                  =N+2: after reordering, roundoff changed values of   
                        some complex eigenvalues so that leading   
                        eigenvalues in the Generalized Schur form no   
                        longer satisfy DELZTG=.TRUE.  This could also   
                        be caused due to scaling.   
                  =N+3: reordering failed in DTGSEN.   

    =====================================================================   


       Decode the input arguments   

       Parameter adjustments */
    /* Table of constant values */
    static integer c__1 = 1;
    static integer c__0 = 0;
    static integer c_n1 = -1;
    static doublereal c_b33 = 0.;
    static doublereal c_b34 = 1.;
    
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, vsl_dim1, vsl_offset, 
	    vsr_dim1, vsr_offset, i__1, i__2;
    doublereal d__1;
    /* Builtin functions */
    double sqrt(doublereal);
    /* Local variables */
    static doublereal anrm, bnrm;
    static integer idum[1], ierr, itau, iwrk;
    static doublereal pvsl, pvsr;
    static integer i__;
    extern logical lsame_(char *, char *);
    static integer ileft, icols;
    static logical cursl, ilvsl, ilvsr;
    static integer irows;
    extern /* Subroutine */ int dlabad_(doublereal *, doublereal *), dggbak_(
	    char *, char *, integer *, integer *, integer *, doublereal *, 
	    doublereal *, integer *, doublereal *, integer *, integer *), dggbal_(char *, integer *, doublereal *, integer 
	    *, doublereal *, integer *, integer *, integer *, doublereal *, 
	    doublereal *, doublereal *, integer *);
    static logical lst2sl;
    extern doublereal dlamch_(char *);
    static integer ip;
    extern doublereal dlange_(char *, integer *, integer *, doublereal *, 
	    integer *, doublereal *);
    extern /* Subroutine */ int dgghrd_(char *, char *, integer *, integer *, 
	    integer *, doublereal *, integer *, doublereal *, integer *, 
	    doublereal *, integer *, doublereal *, integer *, integer *), dlascl_(char *, integer *, integer *, doublereal 
	    *, doublereal *, integer *, integer *, doublereal *, integer *, 
	    integer *);
    static logical ilascl, ilbscl;
    extern /* Subroutine */ int dgeqrf_(integer *, integer *, doublereal *, 
	    integer *, doublereal *, doublereal *, integer *, integer *), 
	    dlacpy_(char *, integer *, integer *, doublereal *, integer *, 
	    doublereal *, integer *);
    static doublereal safmin;
    extern /* Subroutine */ int dlaset_(char *, integer *, integer *, 
	    doublereal *, doublereal *, doublereal *, integer *);
    static doublereal safmax;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    static doublereal bignum;
    extern /* Subroutine */ int dhgeqz_(char *, char *, char *, integer *, 
	    integer *, integer *, doublereal *, integer *, doublereal *, 
	    integer *, doublereal *, doublereal *, doublereal *, doublereal *,
	     integer *, doublereal *, integer *, doublereal *, integer *, 
	    integer *);
    extern integer ilaenv_(integer *, char *, char *, integer *, integer *, 
	    integer *, integer *, ftnlen, ftnlen);
    extern /* Subroutine */ int dtgsen_(integer *, logical *, logical *, 
	    logical *, integer *, doublereal *, integer *, doublereal *, 
	    integer *, doublereal *, doublereal *, doublereal *, doublereal *,
	     integer *, doublereal *, integer *, integer *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, integer *, integer *, 
	    integer *, integer *);
    static integer ijobvl, iright, ijobvr;
    extern /* Subroutine */ int dorgqr_(integer *, integer *, integer *, 
	    doublereal *, integer *, doublereal *, doublereal *, integer *, 
	    integer *);
    static doublereal anrmto, bnrmto;
    static logical lastsl;
    extern /* Subroutine */ int dormqr_(char *, char *, integer *, integer *, 
	    integer *, doublereal *, integer *, doublereal *, doublereal *, 
	    integer *, doublereal *, integer *, integer *);
    static integer minwrk, maxwrk;
    static doublereal smlnum;
    static logical wantst, lquery;
    static doublereal dif[2];
    static integer ihi, ilo;
    static doublereal eps;
#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1]
#define b_ref(a_1,a_2) b[(a_2)*b_dim1 + a_1]
#define vsl_ref(a_1,a_2) vsl[(a_2)*vsl_dim1 + a_1]


    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1 * 1;
    b -= b_offset;
    --alphar;
    --alphai;
    --beta;
    vsl_dim1 = *ldvsl;
    vsl_offset = 1 + vsl_dim1 * 1;
    vsl -= vsl_offset;
    vsr_dim1 = *ldvsr;
    vsr_offset = 1 + vsr_dim1 * 1;
    vsr -= vsr_offset;
    --work;
    --bwork;

    /* Function Body */
    if (lsame_(jobvsl, "N")) {
	ijobvl = 1;
	ilvsl = FALSE_;
    } else if (lsame_(jobvsl, "V")) {
	ijobvl = 2;
	ilvsl = TRUE_;
    } else {
	ijobvl = -1;
	ilvsl = FALSE_;
    }

    if (lsame_(jobvsr, "N")) {
	ijobvr = 1;
	ilvsr = FALSE_;
    } else if (lsame_(jobvsr, "V")) {
	ijobvr = 2;
	ilvsr = TRUE_;
    } else {
	ijobvr = -1;
	ilvsr = FALSE_;
    }

    wantst = lsame_(sort, "S");

/*     Test the input arguments */

    *info = 0;
    lquery = *lwork == -1;
    if (ijobvl <= 0) {
	*info = -1;
    } else if (ijobvr <= 0) {
	*info = -2;
    } else if (! wantst && ! lsame_(sort, "N")) {
	*info = -3;
    } else if (*n < 0) {
	*info = -5;
    } else if (*lda < max(1,*n)) {
	*info = -7;
    } else if (*ldb < max(1,*n)) {
	*info = -9;
    } else if (*ldvsl < 1 || ilvsl && *ldvsl < *n) {
	*info = -15;
    } else if (*ldvsr < 1 || ilvsr && *ldvsr < *n) {
	*info = -17;
    }

/*     Compute workspace   
        (Note: Comments in the code beginning "Workspace:" describe the   
         minimal amount of workspace needed at that point in the code,   
         as well as the preferred amount for good performance.   
         NB refers to the optimal block size for the immediately   
         following subroutine, as returned by ILAENV.) */

    minwrk = 1;
    if (*info == 0 && (*lwork >= 1 || lquery)) {
	minwrk = (*n + 1) * 7 + 16;
	maxwrk = (*n + 1) * 7 + *n * ilaenv_(&c__1, "DGEQRF", " ", n, &c__1, 
		n, &c__0, (ftnlen)6, (ftnlen)1) + 16;
	if (ilvsl) {
/* Computing MAX */
	    i__1 = maxwrk, i__2 = (*n + 1) * 7 + *n * ilaenv_(&c__1, "DORGQR",
		     " ", n, &c__1, n, &c_n1, (ftnlen)6, (ftnlen)1);
	    maxwrk = max(i__1,i__2);
	}
	work[1] = (doublereal) maxwrk;
    }

    if (*lwork < minwrk && ! lquery) {
	*info = -19;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("DGGES ", &i__1);
	return 0;
    } else if (lquery) {
	return 0;
    }

/*     Quick return if possible */

    if (*n == 0) {
	*sdim = 0;
	return 0;
    }

/*     Get machine constants */

    eps = dlamch_("P");
    safmin = dlamch_("S");
    safmax = 1. / safmin;
    dlabad_(&safmin, &safmax);
    smlnum = sqrt(safmin) / eps;
    bignum = 1. / smlnum;

/*     Scale A if max element outside range [SMLNUM,BIGNUM] */

    anrm = dlange_("M", n, n, &a[a_offset], lda, &work[1]);
    ilascl = FALSE_;
    if (anrm > 0. && anrm < smlnum) {
	anrmto = smlnum;
	ilascl = TRUE_;
    } else if (anrm > bignum) {
	anrmto = bignum;
	ilascl = TRUE_;
    }
    if (ilascl) {
	dlascl_("G", &c__0, &c__0, &anrm, &anrmto, n, n, &a[a_offset], lda, &
		ierr);
    }

/*     Scale B if max element outside range [SMLNUM,BIGNUM] */

    bnrm = dlange_("M", n, n, &b[b_offset], ldb, &work[1]);
    ilbscl = FALSE_;
    if (bnrm > 0. && bnrm < smlnum) {
	bnrmto = smlnum;
	ilbscl = TRUE_;
    } else if (bnrm > bignum) {
	bnrmto = bignum;
	ilbscl = TRUE_;
    }
    if (ilbscl) {
	dlascl_("G", &c__0, &c__0, &bnrm, &bnrmto, n, n, &b[b_offset], ldb, &
		ierr);
    }

/*     Permute the matrix to make it more nearly triangular   
       (Workspace: need 6*N + 2*N space for storing balancing factors) */

    ileft = 1;
    iright = *n + 1;
    iwrk = iright + *n;
    dggbal_("P", n, &a[a_offset], lda, &b[b_offset], ldb, &ilo, &ihi, &work[
	    ileft], &work[iright], &work[iwrk], &ierr);

/*     Reduce B to triangular form (QR decomposition of B)   
       (Workspace: need N, prefer N*NB) */

    irows = ihi + 1 - ilo;
    icols = *n + 1 - ilo;
    itau = iwrk;
    iwrk = itau + irows;
    i__1 = *lwork + 1 - iwrk;
    dgeqrf_(&irows, &icols, &b_ref(ilo, ilo), ldb, &work[itau], &work[iwrk], &
	    i__1, &ierr);

/*     Apply the orthogonal transformation to matrix A   
       (Workspace: need N, prefer N*NB) */

    i__1 = *lwork + 1 - iwrk;
    dormqr_("L", "T", &irows, &icols, &irows, &b_ref(ilo, ilo), ldb, &work[
	    itau], &a_ref(ilo, ilo), lda, &work[iwrk], &i__1, &ierr);

/*     Initialize VSL   
       (Workspace: need N, prefer N*NB) */

    if (ilvsl) {
	dlaset_("Full", n, n, &c_b33, &c_b34, &vsl[vsl_offset], ldvsl);
	i__1 = irows - 1;
	i__2 = irows - 1;
	dlacpy_("L", &i__1, &i__2, &b_ref(ilo + 1, ilo), ldb, &vsl_ref(ilo + 
		1, ilo), ldvsl);
	i__1 = *lwork + 1 - iwrk;
	dorgqr_(&irows, &irows, &irows, &vsl_ref(ilo, ilo), ldvsl, &work[itau]
		, &work[iwrk], &i__1, &ierr);
    }

/*     Initialize VSR */

    if (ilvsr) {
	dlaset_("Full", n, n, &c_b33, &c_b34, &vsr[vsr_offset], ldvsr);
    }

/*     Reduce to generalized Hessenberg form   
       (Workspace: none needed) */

    dgghrd_(jobvsl, jobvsr, n, &ilo, &ihi, &a[a_offset], lda, &b[b_offset], 
	    ldb, &vsl[vsl_offset], ldvsl, &vsr[vsr_offset], ldvsr, &ierr);

/*     Perform QZ algorithm, computing Schur vectors if desired   
       (Workspace: need N) */

    iwrk = itau;
    i__1 = *lwork + 1 - iwrk;
    dhgeqz_("S", jobvsl, jobvsr, n, &ilo, &ihi, &a[a_offset], lda, &b[
	    b_offset], ldb, &alphar[1], &alphai[1], &beta[1], &vsl[vsl_offset]
	    , ldvsl, &vsr[vsr_offset], ldvsr, &work[iwrk], &i__1, &ierr);
    if (ierr != 0) {
	if (ierr > 0 && ierr <= *n) {
	    *info = ierr;
	} else if (ierr > *n && ierr <= *n << 1) {
	    *info = ierr - *n;
	} else {
	    *info = *n + 1;
	}
	goto L50;
    }

/*     Sort eigenvalues ALPHA/BETA if desired   
       (Workspace: need 4*N+16 ) */

    *sdim = 0;
    if (wantst) {

/*        Undo scaling on eigenvalues before DELZTGing */

	if (ilascl) {
	    dlascl_("G", &c__0, &c__0, &anrmto, &anrm, n, &c__1, &alphar[1], 
		    n, &ierr);
	    dlascl_("G", &c__0, &c__0, &anrmto, &anrm, n, &c__1, &alphai[1], 
		    n, &ierr);
	}
	if (ilbscl) {
	    dlascl_("G", &c__0, &c__0, &bnrmto, &bnrm, n, &c__1, &beta[1], n, 
		    &ierr);
	}

/*        Select eigenvalues */

	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    bwork[i__] = (*delctg)(&alphar[i__], &alphai[i__], &beta[i__]);
/* L10: */
	}

	i__1 = *lwork - iwrk + 1;
	dtgsen_(&c__0, &ilvsl, &ilvsr, &bwork[1], n, &a[a_offset], lda, &b[
		b_offset], ldb, &alphar[1], &alphai[1], &beta[1], &vsl[
		vsl_offset], ldvsl, &vsr[vsr_offset], ldvsr, sdim, &pvsl, &
		pvsr, dif, &work[iwrk], &i__1, idum, &c__1, &ierr);
	if (ierr == 1) {
	    *info = *n + 3;
	}

    }

/*     Apply back-permutation to VSL and VSR   
       (Workspace: none needed) */

    if (ilvsl) {
	dggbak_("P", "L", n, &ilo, &ihi, &work[ileft], &work[iright], n, &vsl[
		vsl_offset], ldvsl, &ierr);
    }

    if (ilvsr) {
	dggbak_("P", "R", n, &ilo, &ihi, &work[ileft], &work[iright], n, &vsr[
		vsr_offset], ldvsr, &ierr);
    }

/*     Check if unscaling would cause over/underflow, if so, rescale   
       (ALPHAR(I),ALPHAI(I),BETA(I)) so BETA(I) is on the order of   
       B(I,I) and ALPHAR(I) and ALPHAI(I) are on the order of A(I,I) */

    if (ilascl) {
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    if (alphai[i__] != 0.) {
		if (alphar[i__] / safmax > anrmto / anrm || safmin / alphar[
			i__] > anrm / anrmto) {
		    work[1] = (d__1 = a_ref(i__, i__) / alphar[i__], abs(d__1)
			    );
		    beta[i__] *= work[1];
		    alphar[i__] *= work[1];
		    alphai[i__] *= work[1];
		} else if (alphai[i__] / safmax > anrmto / anrm || safmin / 
			alphai[i__] > anrm / anrmto) {
		    work[1] = (d__1 = a_ref(i__, i__ + 1) / alphai[i__], abs(
			    d__1));
		    beta[i__] *= work[1];
		    alphar[i__] *= work[1];
		    alphai[i__] *= work[1];
		}
	    }
/* L20: */
	}
    }

    if (ilbscl) {
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    if (alphai[i__] != 0.) {
		if (beta[i__] / safmax > bnrmto / bnrm || safmin / beta[i__] 
			> bnrm / bnrmto) {
		    work[1] = (d__1 = b_ref(i__, i__) / beta[i__], abs(d__1));
		    beta[i__] *= work[1];
		    alphar[i__] *= work[1];
		    alphai[i__] *= work[1];
		}
	    }
/* L30: */
	}
    }

/*     Undo scaling */

    if (ilascl) {
	dlascl_("H", &c__0, &c__0, &anrmto, &anrm, n, n, &a[a_offset], lda, &
		ierr);
	dlascl_("G", &c__0, &c__0, &anrmto, &anrm, n, &c__1, &alphar[1], n, &
		ierr);
	dlascl_("G", &c__0, &c__0, &anrmto, &anrm, n, &c__1, &alphai[1], n, &
		ierr);
    }

    if (ilbscl) {
	dlascl_("U", &c__0, &c__0, &bnrmto, &bnrm, n, n, &b[b_offset], ldb, &
		ierr);
	dlascl_("G", &c__0, &c__0, &bnrmto, &bnrm, n, &c__1, &beta[1], n, &
		ierr);
    }

    if (wantst) {

/*        Check if reordering is correct */

	lastsl = TRUE_;
	lst2sl = TRUE_;
	*sdim = 0;
	ip = 0;
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    cursl = (*delctg)(&alphar[i__], &alphai[i__], &beta[i__]);
	    if (alphai[i__] == 0.) {
		if (cursl) {
		    ++(*sdim);
		}
		ip = 0;
		if (cursl && ! lastsl) {
		    *info = *n + 2;
		}
	    } else {
		if (ip == 1) {

/*                 Last eigenvalue of conjugate pair */

		    cursl = cursl || lastsl;
		    lastsl = cursl;
		    if (cursl) {
			*sdim += 2;
		    }
		    ip = -1;
		    if (cursl && ! lst2sl) {
			*info = *n + 2;
		    }
		} else {

/*                 First eigenvalue of conjugate pair */

		    ip = 1;
		}
	    }
	    lst2sl = lastsl;
	    lastsl = cursl;
/* L40: */
	}

    }

L50:

    work[1] = (doublereal) maxwrk;

    return 0;

/*     End of DGGES */

} /* dgges_ */

#undef vsl_ref
#undef b_ref
#undef a_ref


