text: /* zheevr.f -- translated by f2c (version 20061008).
     You must link the resulting object file with libf2c:
  	on Microsoft Windows system, link with libf2c.lib;
  	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
  	or, if you install libf2c.a in a standard place, with -lf2c -lm
  	-- in that order, at the end of the command line, as in
  		cc *.o -lf2c -lm
  	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
  
  		http://www.netlib.org/f2c/libf2c.zip
  */
  
  #include "f2c.h"
  #include "blaswrap.h"
  
  /* Table of constant values */
  
  static integer c__10 = 10;
  static integer c__1 = 1;
  static integer c__2 = 2;
  static integer c__3 = 3;
  static integer c__4 = 4;
  static integer c_n1 = -1;
  
  /* Subroutine */ int zheevr_(char *jobz, char *range, char *uplo, integer *n, 
  	doublecomplex *a, integer *lda, doublereal *vl, doublereal *vu, 
  	integer *il, integer *iu, doublereal *abstol, integer *m, doublereal *
  	w, doublecomplex *z__, integer *ldz, integer *isuppz, doublecomplex *
  	work, integer *lwork, doublereal *rwork, integer *lrwork, integer *
  	iwork, integer *liwork, integer *info)
  {
      /* System generated locals */
      integer a_dim1, a_offset, z_dim1, z_offset, i__1, i__2;
      doublereal d__1, d__2;
  
      /* Builtin functions */
      double sqrt(doublereal);
  
      /* Local variables */
      integer i__, j, nb, jj;
      doublereal eps, vll, vuu, tmp1, anrm;
      integer imax;
      doublereal rmin, rmax;
      logical test;
      integer itmp1;
      extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, 
  	    integer *);
      integer indrd, indre;
      doublereal sigma;
      extern logical lsame_(char *, char *);
      integer iinfo;
      char order[1];
      integer indwk;
      extern /* Subroutine */ int dcopy_(integer *, doublereal *, integer *, 
  	    doublereal *, integer *);
      integer lwmin;
      logical lower, wantz;
      extern /* Subroutine */ int zswap_(integer *, doublecomplex *, integer *, 
  	    doublecomplex *, integer *);
      extern doublereal dlamch_(char *);
      logical alleig, indeig;
      integer iscale, ieeeok, indibl, indrdd, indifl, indree;
      logical valeig;
      doublereal safmin;
      extern integer ilaenv_(integer *, char *, char *, integer *, integer *, 
  	    integer *, integer *);
      extern /* Subroutine */ int xerbla_(char *, integer *), zdscal_(
  	    integer *, doublereal *, doublecomplex *, integer *);
      doublereal abstll, bignum;
      integer indtau, indisp;
      extern /* Subroutine */ int dsterf_(integer *, doublereal *, doublereal *, 
  	     integer *);
      integer indiwo, indwkn;
      extern /* Subroutine */ int dstebz_(char *, char *, integer *, doublereal 
  	    *, doublereal *, integer *, integer *, doublereal *, doublereal *, 
  	     doublereal *, integer *, integer *, doublereal *, integer *, 
  	    integer *, doublereal *, integer *, integer *);
      integer indrwk, liwmin;
      extern /* Subroutine */ int zhetrd_(char *, integer *, doublecomplex *, 
  	    integer *, doublereal *, doublereal *, doublecomplex *, 
  	    doublecomplex *, integer *, integer *);
      logical tryrac;
      integer lrwmin, llwrkn, llwork, nsplit;
      doublereal smlnum;
      extern /* Subroutine */ int zstein_(integer *, doublereal *, doublereal *, 
  	     integer *, doublereal *, integer *, integer *, doublecomplex *, 
  	    integer *, doublereal *, integer *, integer *, integer *);
      logical lquery;
      integer lwkopt;
      extern doublereal zlansy_(char *, char *, integer *, doublecomplex *, 
  	    integer *, doublereal *);
      extern /* Subroutine */ int zstemr_(char *, char *, integer *, doublereal 
  	    *, doublereal *, doublereal *, doublereal *, integer *, integer *, 
  	     integer *, doublereal *, doublecomplex *, integer *, integer *, 
  	    integer *, logical *, doublereal *, integer *, integer *, integer 
  	    *, integer *), zunmtr_(char *, char *, char *, 
  	    integer *, integer *, doublecomplex *, integer *, doublecomplex *, 
  	     doublecomplex *, integer *, doublecomplex *, integer *, integer *
  );
      integer llrwork;
  
  
  /*  -- LAPACK driver routine (version 3.2) -- */
  /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
  /*     November 2006 */
  
  /*     .. Scalar Arguments .. */
  /*     .. */
  /*     .. Array Arguments .. */
  /*     .. */
  
  /*  Purpose */
  /*  ======= */
  
  /*  ZHEEVR computes selected eigenvalues and, optionally, eigenvectors */
  /*  of a complex Hermitian matrix A.  Eigenvalues and eigenvectors can */
  /*  be selected by specifying either a range of values or a range of */
  /*  indices for the desired eigenvalues. */
  
  /*  ZHEEVR first reduces the matrix A to tridiagonal form T with a call */
  /*  to ZHETRD.  Then, whenever possible, ZHEEVR calls ZSTEMR to compute */
  /*  eigenspectrum using Relatively Robust Representations.  ZSTEMR */
  /*  computes eigenvalues by the dqds algorithm, while orthogonal */
  /*  eigenvectors are computed from various "good" L D L^T representations */
  /*  (also known as Relatively Robust Representations). Gram-Schmidt */
  /*  orthogonalization is avoided as far as possible. More specifically, */
  /*  the various steps of the algorithm are as follows. */
  
  /*  For each unreduced block (submatrix) of T, */
  /*     (a) Compute T - sigma I  = L D L^T, so that L and D */
  /*         define all the wanted eigenvalues to high relative accuracy. */
  /*         This means that small relative changes in the entries of D and L */
  /*         cause only small relative changes in the eigenvalues and */
  /*         eigenvectors. The standard (unfactored) representation of the */
  /*         tridiagonal matrix T does not have this property in general. */
  /*     (b) Compute the eigenvalues to suitable accuracy. */
  /*         If the eigenvectors are desired, the algorithm attains full */
  /*         accuracy of the computed eigenvalues only right before */
  /*         the corresponding vectors have to be computed, see steps c) and d). */
  /*     (c) For each cluster of close eigenvalues, select a new */
  /*         shift close to the cluster, find a new factorization, and refine */
  /*         the shifted eigenvalues to suitable accuracy. */
  /*     (d) For each eigenvalue with a large enough relative separation compute */
  /*         the corresponding eigenvector by forming a rank revealing twisted */
  /*         factorization. Go back to (c) for any clusters that remain. */
  
  /*  The desired accuracy of the output can be specified by the input */
  /*  parameter ABSTOL. */
  
  /*  For more details, see DSTEMR's documentation and: */
  /*  - Inderjit S. Dhillon and Beresford N. Parlett: "Multiple representations */
  /*    to compute orthogonal eigenvectors of symmetric tridiagonal matrices," */
  /*    Linear Algebra and its Applications, 387(1), pp. 1-28, August 2004. */
  /*  - Inderjit Dhillon and Beresford Parlett: "Orthogonal Eigenvectors and */
  /*    Relative Gaps," SIAM Journal on Matrix Analysis and Applications, Vol. 25, */
  /*    2004.  Also LAPACK Working Note 154. */
  /*  - Inderjit Dhillon: "A new O(n^2) algorithm for the symmetric */
  /*    tridiagonal eigenvalue/eigenvector problem", */
  /*    Computer Science Division Technical Report No. UCB/CSD-97-971, */
  /*    UC Berkeley, May 1997. */
  
  
  /*  Note 1 : ZHEEVR calls ZSTEMR when the full spectrum is requested */
  /*  on machines which conform to the ieee-754 floating point standard. */
  /*  ZHEEVR calls DSTEBZ and ZSTEIN on non-ieee machines and */
  /*  when partial spectrum requests are made. */
  
  /*  Normal execution of ZSTEMR may create NaNs and infinities and */
  /*  hence may abort due to a floating point exception in environments */
  /*  which do not handle NaNs and infinities in the ieee standard default */
  /*  manner. */
  
  /*  Arguments */
  /*  ========= */
  
  /*  JOBZ    (input) CHARACTER*1 */
  /*          = 'N':  Compute eigenvalues only; */
  /*          = 'V':  Compute eigenvalues and eigenvectors. */
  
  /*  RANGE   (input) CHARACTER*1 */
  /*          = 'A': all eigenvalues will be found. */
  /*          = 'V': all eigenvalues in the half-open interval (VL,VU] */
  /*                 will be found. */
  /*          = 'I': the IL-th through IU-th eigenvalues will be found. */
  /* ********* For RANGE = 'V' or 'I' and IU - IL < N - 1, DSTEBZ and */
  /* ********* ZSTEIN are called */
  
  /*  UPLO    (input) CHARACTER*1 */
  /*          = 'U':  Upper triangle of A is stored; */
  /*          = 'L':  Lower triangle of A is stored. */
  
  /*  N       (input) INTEGER */
  /*          The order of the matrix A.  N >= 0. */
  
  /*  A       (input/output) COMPLEX*16 array, dimension (LDA, N) */
  /*          On entry, the Hermitian matrix A.  If UPLO = 'U', the */
  /*          leading N-by-N upper triangular part of A contains the */
  /*          upper triangular part of the matrix A.  If UPLO = 'L', */
  /*          the leading N-by-N lower triangular part of A contains */
  /*          the lower triangular part of the matrix A. */
  /*          On exit, the lower triangle (if UPLO='L') or the upper */
  /*          triangle (if UPLO='U') of A, including the diagonal, is */
  /*          destroyed. */
  
  /*  LDA     (input) INTEGER */
  /*          The leading dimension of the array A.  LDA >= max(1,N). */
  
  /*  VL      (input) DOUBLE PRECISION */
  /*  VU      (input) DOUBLE PRECISION */
  /*          If RANGE='V', the lower and upper bounds of the interval to */
  /*          be searched for eigenvalues. VL < VU. */
  /*          Not referenced if RANGE = 'A' or 'I'. */
  
  /*  IL      (input) INTEGER */
  /*  IU      (input) INTEGER */
  /*          If RANGE='I', the indices (in ascending order) of the */
  /*          smallest and largest eigenvalues to be returned. */
  /*          1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. */
  /*          Not referenced if RANGE = 'A' or 'V'. */
  
  /*  ABSTOL  (input) DOUBLE PRECISION */
  /*          The absolute error tolerance for the eigenvalues. */
  /*          An approximate eigenvalue is accepted as converged */
  /*          when it is determined to lie in an interval [a,b] */
  /*          of width less than or equal to */
  
  /*                  ABSTOL + EPS *   max( |a|,|b| ) , */
  
  /*          where EPS is the machine precision.  If ABSTOL is less than */
  /*          or equal to zero, then  EPS*|T|  will be used in its place, */
  /*          where |T| is the 1-norm of the tridiagonal matrix obtained */
  /*          by reducing A to tridiagonal form. */
  
  /*          See "Computing Small Singular Values of Bidiagonal Matrices */
  /*          with Guaranteed High Relative Accuracy," by Demmel and */
  /*          Kahan, LAPACK Working Note #3. */
  
  /*          If high relative accuracy is important, set ABSTOL to */
  /*          DLAMCH( 'Safe minimum' ).  Doing so will guarantee that */
  /*          eigenvalues are computed to high relative accuracy when */
  /*          possible in future releases.  The current code does not */
  /*          make any guarantees about high relative accuracy, but */
  /*          furutre releases will. See J. Barlow and J. Demmel, */
  /*          "Computing Accurate Eigensystems of Scaled Diagonally */
  /*          Dominant Matrices", LAPACK Working Note #7, for a discussion */
  /*          of which matrices define their eigenvalues to high relative */
  /*          accuracy. */
  
  /*  M       (output) INTEGER */
  /*          The total number of eigenvalues found.  0 <= M <= N. */
  /*          If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. */
  
  /*  W       (output) DOUBLE PRECISION array, dimension (N) */
  /*          The first M elements contain the selected eigenvalues in */
  /*          ascending order. */
  
  /*  Z       (output) COMPLEX*16 array, dimension (LDZ, max(1,M)) */
  /*          If JOBZ = 'V', then if INFO = 0, the first M columns of Z */
  /*          contain the orthonormal eigenvectors of the matrix A */
  /*          corresponding to the selected eigenvalues, with the i-th */
  /*          column of Z holding the eigenvector associated with W(i). */
  /*          If JOBZ = 'N', then Z is not referenced. */
  /*          Note: the user must ensure that at least max(1,M) columns are */
  /*          supplied in the array Z; if RANGE = 'V', the exact value of M */
  /*          is not known in advance and an upper bound must be used. */
  
  /*  LDZ     (input) INTEGER */
  /*          The leading dimension of the array Z.  LDZ >= 1, and if */
  /*          JOBZ = 'V', LDZ >= max(1,N). */
  
  /*  ISUPPZ  (output) INTEGER array, dimension ( 2*max(1,M) ) */
  /*          The support of the eigenvectors in Z, i.e., the indices */
  /*          indicating the nonzero elements in Z. The i-th eigenvector */
  /*          is nonzero only in elements ISUPPZ( 2*i-1 ) through */
  /*          ISUPPZ( 2*i ). */
  /* ********* Implemented only for RANGE = 'A' or 'I' and IU - IL = N - 1 */
  
  /*  WORK    (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) */
  /*          On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
  
  /*  LWORK   (input) INTEGER */
  /*          The length of the array WORK.  LWORK >= max(1,2*N). */
  /*          For optimal efficiency, LWORK >= (NB+1)*N, */
  /*          where NB is the max of the blocksize for ZHETRD and for */
  /*          ZUNMTR as returned by ILAENV. */
  
  /*          If LWORK = -1, then a workspace query is assumed; the routine */
  /*          only calculates the optimal sizes of the WORK, RWORK and */
  /*          IWORK arrays, returns these values as the first entries of */
  /*          the WORK, RWORK and IWORK arrays, and no error message */
  /*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */
  
  /*  RWORK   (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LRWORK)) */
  /*          On exit, if INFO = 0, RWORK(1) returns the optimal */
  /*          (and minimal) LRWORK. */
  
  /* LRWORK   (input) INTEGER */
  /*          The length of the array RWORK.  LRWORK >= max(1,24*N). */
  
  /*          If LRWORK = -1, then a workspace query is assumed; the */
  /*          routine only calculates the optimal sizes of the WORK, RWORK */
  /*          and IWORK arrays, returns these values as the first entries */
  /*          of the WORK, RWORK and IWORK arrays, and no error message */
  /*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */
  
  /*  IWORK   (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) */
  /*          On exit, if INFO = 0, IWORK(1) returns the optimal */
  /*          (and minimal) LIWORK. */
  
  /* LIWORK   (input) INTEGER */
  /*          The dimension of the array IWORK.  LIWORK >= max(1,10*N). */
  
  /*          If LIWORK = -1, then a workspace query is assumed; the */
  /*          routine only calculates the optimal sizes of the WORK, RWORK */
  /*          and IWORK arrays, returns these values as the first entries */
  /*          of the WORK, RWORK and IWORK arrays, and no error message */
  /*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */
  
  /*  INFO    (output) INTEGER */
  /*          = 0:  successful exit */
  /*          < 0:  if INFO = -i, the i-th argument had an illegal value */
  /*          > 0:  Internal error */
  
  /*  Further Details */
  /*  =============== */
  
  /*  Based on contributions by */
  /*     Inderjit Dhillon, IBM Almaden, USA */
  /*     Osni Marques, LBNL/NERSC, USA */
  /*     Ken Stanley, Computer Science Division, University of */
  /*       California at Berkeley, USA */
  /*     Jason Riedy, Computer Science Division, University of */
  /*       California at Berkeley, USA */
  
  /* ===================================================================== */
  
  /*     .. Parameters .. */
  /*     .. */
  /*     .. Local Scalars .. */
  /*     .. */
  /*     .. External Functions .. */
  /*     .. */
  /*     .. External Subroutines .. */
  /*     .. */
  /*     .. Intrinsic Functions .. */
  /*     .. */
  /*     .. Executable Statements .. */
  
  /*     Test the input parameters. */
  
      /* Parameter adjustments */
      a_dim1 = *lda;
      a_offset = 1 + a_dim1;
      a -= a_offset;
      --w;
      z_dim1 = *ldz;
      z_offset = 1 + z_dim1;
      z__ -= z_offset;
      --isuppz;
      --work;
      --rwork;
      --iwork;
  
      /* Function Body */
      ieeeok = ilaenv_(&c__10, "ZHEEVR", "N", &c__1, &c__2, &c__3, &c__4);
  
      lower = lsame_(uplo, "L");
      wantz = lsame_(jobz, "V");
      alleig = lsame_(range, "A");
      valeig = lsame_(range, "V");
      indeig = lsame_(range, "I");
  
      lquery = *lwork == -1 || *lrwork == -1 || *liwork == -1;
  
  /* Computing MAX */
      i__1 = 1, i__2 = *n * 24;
      lrwmin = max(i__1,i__2);
  /* Computing MAX */
      i__1 = 1, i__2 = *n * 10;
      liwmin = max(i__1,i__2);
  /* Computing MAX */
      i__1 = 1, i__2 = *n << 1;
      lwmin = max(i__1,i__2);
  
      *info = 0;
      if (! (wantz || lsame_(jobz, "N"))) {
  	*info = -1;
      } else if (! (alleig || valeig || indeig)) {
  	*info = -2;
      } else if (! (lower || lsame_(uplo, "U"))) {
  	*info = -3;
      } else if (*n < 0) {
  	*info = -4;
      } else if (*lda < max(1,*n)) {
  	*info = -6;
      } else {
  	if (valeig) {
  	    if (*n > 0 && *vu <= *vl) {
  		*info = -8;
  	    }
  	} else if (indeig) {
  	    if (*il < 1 || *il > max(1,*n)) {
  		*info = -9;
  	    } else if (*iu < min(*n,*il) || *iu > *n) {
  		*info = -10;
  	    }
  	}
      }
      if (*info == 0) {
  	if (*ldz < 1 || wantz && *ldz < *n) {
  	    *info = -15;
  	}
      }
  
      if (*info == 0) {
  	nb = ilaenv_(&c__1, "ZHETRD", uplo, n, &c_n1, &c_n1, &c_n1);
  /* Computing MAX */
  	i__1 = nb, i__2 = ilaenv_(&c__1, "ZUNMTR", uplo, n, &c_n1, &c_n1, &
  		c_n1);
  	nb = max(i__1,i__2);
  /* Computing MAX */
  	i__1 = (nb + 1) * *n;
  	lwkopt = max(i__1,lwmin);
  	work[1].r = (doublereal) lwkopt, work[1].i = 0.;
  	rwork[1] = (doublereal) lrwmin;
  	iwork[1] = liwmin;
  
  	if (*lwork < lwmin && ! lquery) {
  	    *info = -18;
  	} else if (*lrwork < lrwmin && ! lquery) {
  	    *info = -20;
  	} else if (*liwork < liwmin && ! lquery) {
  	    *info = -22;
  	}
      }
  
      if (*info != 0) {
  	i__1 = -(*info);
  	xerbla_("ZHEEVR", &i__1);
  	return 0;
      } else if (lquery) {
  	return 0;
      }
  
  /*     Quick return if possible */
  
      *m = 0;
      if (*n == 0) {
  	work[1].r = 1., work[1].i = 0.;
  	return 0;
      }
  
      if (*n == 1) {
  	work[1].r = 2., work[1].i = 0.;
  	if (alleig || indeig) {
  	    *m = 1;
  	    i__1 = a_dim1 + 1;
  	    w[1] = a[i__1].r;
  	} else {
  	    i__1 = a_dim1 + 1;
  	    i__2 = a_dim1 + 1;
  	    if (*vl < a[i__1].r && *vu >= a[i__2].r) {
  		*m = 1;
  		i__1 = a_dim1 + 1;
  		w[1] = a[i__1].r;
  	    }
  	}
  	if (wantz) {
  	    i__1 = z_dim1 + 1;
  	    z__[i__1].r = 1., z__[i__1].i = 0.;
  	}
  	return 0;
      }
  
  /*     Get machine constants. */
  
      safmin = dlamch_("Safe minimum");
      eps = dlamch_("Precision");
      smlnum = safmin / eps;
      bignum = 1. / smlnum;
      rmin = sqrt(smlnum);
  /* Computing MIN */
      d__1 = sqrt(bignum), d__2 = 1. / sqrt(sqrt(safmin));
      rmax = min(d__1,d__2);
  
  /*     Scale matrix to allowable range, if necessary. */
  
      iscale = 0;
      abstll = *abstol;
      if (valeig) {
  	vll = *vl;
  	vuu = *vu;
      }
      anrm = zlansy_("M", uplo, n, &a[a_offset], lda, &rwork[1]);
      if (anrm > 0. && anrm < rmin) {
  	iscale = 1;
  	sigma = rmin / anrm;
      } else if (anrm > rmax) {
  	iscale = 1;
  	sigma = rmax / anrm;
      }
      if (iscale == 1) {
  	if (lower) {
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		i__2 = *n - j + 1;
  		zdscal_(&i__2, &sigma, &a[j + j * a_dim1], &c__1);
  /* L10: */
  	    }
  	} else {
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		zdscal_(&j, &sigma, &a[j * a_dim1 + 1], &c__1);
  /* L20: */
  	    }
  	}
  	if (*abstol > 0.) {
  	    abstll = *abstol * sigma;
  	}
  	if (valeig) {
  	    vll = *vl * sigma;
  	    vuu = *vu * sigma;
  	}
      }
  /*     Initialize indices into workspaces.  Note: The IWORK indices are */
  /*     used only if DSTERF or ZSTEMR fail. */
  /*     WORK(INDTAU:INDTAU+N-1) stores the complex scalar factors of the */
  /*     elementary reflectors used in ZHETRD. */
      indtau = 1;
  /*     INDWK is the starting offset of the remaining complex workspace, */
  /*     and LLWORK is the remaining complex workspace size. */
      indwk = indtau + *n;
      llwork = *lwork - indwk + 1;
  /*     RWORK(INDRD:INDRD+N-1) stores the real tridiagonal's diagonal */
  /*     entries. */
      indrd = 1;
  /*     RWORK(INDRE:INDRE+N-1) stores the off-diagonal entries of the */
  /*     tridiagonal matrix from ZHETRD. */
      indre = indrd + *n;
  /*     RWORK(INDRDD:INDRDD+N-1) is a copy of the diagonal entries over */
  /*     -written by ZSTEMR (the DSTERF path copies the diagonal to W). */
      indrdd = indre + *n;
  /*     RWORK(INDREE:INDREE+N-1) is a copy of the off-diagonal entries over */
  /*     -written while computing the eigenvalues in DSTERF and ZSTEMR. */
      indree = indrdd + *n;
  /*     INDRWK is the starting offset of the left-over real workspace, and */
  /*     LLRWORK is the remaining workspace size. */
      indrwk = indree + *n;
      llrwork = *lrwork - indrwk + 1;
  /*     IWORK(INDIBL:INDIBL+M-1) corresponds to IBLOCK in DSTEBZ and */
  /*     stores the block indices of each of the M<=N eigenvalues. */
      indibl = 1;
  /*     IWORK(INDISP:INDISP+NSPLIT-1) corresponds to ISPLIT in DSTEBZ and */
  /*     stores the starting and finishing indices of each block. */
      indisp = indibl + *n;
  /*     IWORK(INDIFL:INDIFL+N-1) stores the indices of eigenvectors */
  /*     that corresponding to eigenvectors that fail to converge in */
  /*     DSTEIN.  This information is discarded; if any fail, the driver */
  /*     returns INFO > 0. */
      indifl = indisp + *n;
  /*     INDIWO is the offset of the remaining integer workspace. */
      indiwo = indisp + *n;
  
  /*     Call ZHETRD to reduce Hermitian matrix to tridiagonal form. */
  
      zhetrd_(uplo, n, &a[a_offset], lda, &rwork[indrd], &rwork[indre], &work[
  	    indtau], &work[indwk], &llwork, &iinfo);
  
  /*     If all eigenvalues are desired */
  /*     then call DSTERF or ZSTEMR and ZUNMTR. */
  
      test = FALSE_;
      if (indeig) {
  	if (*il == 1 && *iu == *n) {
  	    test = TRUE_;
  	}
      }
      if ((alleig || test) && ieeeok == 1) {
  	if (! wantz) {
  	    dcopy_(n, &rwork[indrd], &c__1, &w[1], &c__1);
  	    i__1 = *n - 1;
  	    dcopy_(&i__1, &rwork[indre], &c__1, &rwork[indree], &c__1);
  	    dsterf_(n, &w[1], &rwork[indree], info);
  	} else {
  	    i__1 = *n - 1;
  	    dcopy_(&i__1, &rwork[indre], &c__1, &rwork[indree], &c__1);
  	    dcopy_(n, &rwork[indrd], &c__1, &rwork[indrdd], &c__1);
  
  	    if (*abstol <= *n * 2. * eps) {
  		tryrac = TRUE_;
  	    } else {
  		tryrac = FALSE_;
  	    }
  	    zstemr_(jobz, "A", n, &rwork[indrdd], &rwork[indree], vl, vu, il, 
  		    iu, m, &w[1], &z__[z_offset], ldz, n, &isuppz[1], &tryrac, 
  		     &rwork[indrwk], &llrwork, &iwork[1], liwork, info);
  
  /*           Apply unitary matrix used in reduction to tridiagonal */
  /*           form to eigenvectors returned by ZSTEIN. */
  
  	    if (wantz && *info == 0) {
  		indwkn = indwk;
  		llwrkn = *lwork - indwkn + 1;
  		zunmtr_("L", uplo, "N", n, m, &a[a_offset], lda, &work[indtau]
  , &z__[z_offset], ldz, &work[indwkn], &llwrkn, &iinfo);
  	    }
  	}
  
  
  	if (*info == 0) {
  	    *m = *n;
  	    goto L30;
  	}
  	*info = 0;
      }
  
  /*     Otherwise, call DSTEBZ and, if eigenvectors are desired, ZSTEIN. */
  /*     Also call DSTEBZ and ZSTEIN if ZSTEMR fails. */
  
      if (wantz) {
  	*(unsigned char *)order = 'B';
      } else {
  	*(unsigned char *)order = 'E';
      }
      dstebz_(range, order, n, &vll, &vuu, il, iu, &abstll, &rwork[indrd], &
  	    rwork[indre], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &
  	    rwork[indrwk], &iwork[indiwo], info);
  
      if (wantz) {
  	zstein_(n, &rwork[indrd], &rwork[indre], m, &w[1], &iwork[indibl], &
  		iwork[indisp], &z__[z_offset], ldz, &rwork[indrwk], &iwork[
  		indiwo], &iwork[indifl], info);
  
  /*        Apply unitary matrix used in reduction to tridiagonal */
  /*        form to eigenvectors returned by ZSTEIN. */
  
  	indwkn = indwk;
  	llwrkn = *lwork - indwkn + 1;
  	zunmtr_("L", uplo, "N", n, m, &a[a_offset], lda, &work[indtau], &z__[
  		z_offset], ldz, &work[indwkn], &llwrkn, &iinfo);
      }
  
  /*     If matrix was scaled, then rescale eigenvalues appropriately. */
  
  L30:
      if (iscale == 1) {
  	if (*info == 0) {
  	    imax = *m;
  	} else {
  	    imax = *info - 1;
  	}
  	d__1 = 1. / sigma;
  	dscal_(&imax, &d__1, &w[1], &c__1);
      }
  
  /*     If eigenvalues are not in order, then sort them, along with */
  /*     eigenvectors. */
  
      if (wantz) {
  	i__1 = *m - 1;
  	for (j = 1; j <= i__1; ++j) {
  	    i__ = 0;
  	    tmp1 = w[j];
  	    i__2 = *m;
  	    for (jj = j + 1; jj <= i__2; ++jj) {
  		if (w[jj] < tmp1) {
  		    i__ = jj;
  		    tmp1 = w[jj];
  		}
  /* L40: */
  	    }
  
  	    if (i__ != 0) {
  		itmp1 = iwork[indibl + i__ - 1];
  		w[i__] = w[j];
  		iwork[indibl + i__ - 1] = iwork[indibl + j - 1];
  		w[j] = tmp1;
  		iwork[indibl + j - 1] = itmp1;
  		zswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[j * z_dim1 + 1], 
  			 &c__1);
  	    }
  /* L50: */
  	}
      }
  
  /*     Set WORK(1) to optimal workspace size. */
  
      work[1].r = (doublereal) lwkopt, work[1].i = 0.;
      rwork[1] = (doublereal) lrwmin;
      iwork[1] = liwmin;
  
      return 0;
  
  /*     End of ZHEEVR */
  
  } /* zheevr_ */
  