      SUBROUTINE PCHEEV( JOBZ, UPLO, N, A, IA, JA, DESCA, W, Z, IZ, JZ,
     $                   DESCZ, WORK, LWORK, RWORK, LRWORK, INFO )
      IMPLICIT NONE
*
*  -- ScaLAPACK routine (version 1.7) --
*     University of Tennessee, Knoxville, Oak Ridge National Laboratory,
*     and University of California, Berkeley.
*     August 14, 2001 
*
*     .. Scalar Arguments ..
      CHARACTER          JOBZ, UPLO
      INTEGER            IA, INFO, IZ, JA, JZ, LRWORK, LWORK, N
*     ..
*     .. Array Arguments ..
      INTEGER            DESCA( * ), DESCZ( * )
      REAL               RWORK( * ), W( * )
      COMPLEX            A( * ), WORK( * ), Z( * )
*     ..
*
*  Purpose
*  =======
*
*  PCHEEV computes selected eigenvalues and, optionally, eigenvectors
*  of a real Hermitian matrix A by calling the recommended sequence
*  of ScaLAPACK routines.
*
*  In its present form, PCHEEV assumes a homogeneous system and makes
*  only spot checks of the consistency of the eigenvalues across the
*  different processes.  Because of this, it is possible that a
*  heterogeneous system may return incorrect results without any error
*  messages.
*
*  Notes
*  =====
*  A description vector is associated with each 2D block-cyclicly dis-
*  tributed matrix.  This vector stores the information required to
*  establish the mapping between a matrix entry and its corresponding
*  process and memory location.
*
*  In the following comments, the character _ should be read as
*  "of the distributed matrix".  Let A be a generic term for any 2D
*  block cyclicly distributed matrix.  Its description vector is DESCA:
*
*  NOTATION        STORED IN      EXPLANATION
*  --------------- -------------- --------------------------------------
*  DTYPE_A(global) DESCA( DTYPE_) The descriptor type.
*  CTXT_A (global) DESCA( CTXT_ ) The BLACS context handle, indicating
*                                 the BLACS process grid A is distribu-
*                                 ted over. The context itself is glo-
*                                 bal, but the handle (the integer
*                                 value) may vary.
*  M_A    (global) DESCA( M_ )    The number of rows in the distributed
*                                 matrix A.
*  N_A    (global) DESCA( N_ )    The number of columns in the distri-
*                                 buted matrix A.
*  MB_A   (global) DESCA( MB_ )   The blocking factor used to distribute
*                                 the rows of A.
*  NB_A   (global) DESCA( NB_ )   The blocking factor used to distribute
*                                 the columns of A.
*  RSRC_A (global) DESCA( RSRC_ ) The process row over which the first
*                                 row of the matrix A is distributed.
*  CSRC_A (global) DESCA( CSRC_ ) The process column over which the
*                                 first column of A is distributed.
*  LLD_A  (local)  DESCA( LLD_ )  The leading dimension of the local
*                                 array storing the local blocks of the
*                                 distributed matrix A.
*                                 LLD_A >= MAX(1,LOCr(M_A)).
*
*  Let K be the number of rows or columns of a distributed matrix,
*  and assume that its process grid has dimension p x q.
*  LOCr( K ) denotes the number of elements of K that a process
*  would receive if K were distributed over the p processes of its
*  process column.
*  Similarly, LOCc( K ) denotes the number of elements of K that a
*  process would receive if K were distributed over the q processes of
*  its process row.
*  The values of LOCr() and LOCc() may be determined via a call to the
*  ScaLAPACK tool function, NUMROC:
*          LOCr( M ) = NUMROC( M, MB_A, MYROW, RSRC_A, NPROW ),
*          LOCc( N ) = NUMROC( N, NB_A, MYCOL, CSRC_A, NPCOL ).
*
*  Arguments
*  =========
*
*     NP = the number of rows local to a given process.
*     NQ = the number of columns local to a given process.
*
*  JOBZ    (global input) CHARACTER*1
*          Specifies whether or not to compute the eigenvectors:
*          = 'N':  Compute eigenvalues only.
*          = 'V':  Compute eigenvalues and eigenvectors.
*
*  UPLO    (global input) CHARACTER*1
*          Specifies whether the upper or lower triangular part of the
*          Hermitian matrix A is stored:
*          = 'U':  Upper triangular
*          = 'L':  Lower triangular
*
*  N       (global input) INTEGER
*          The number of rows and columns of the matrix A.  N >= 0.
*
*  A       (local input/workspace) block cyclic COMPLEX array,
*          global dimension (N, N), local dimension ( LLD_A,
*          LOCc(JA+N-1) )
*
*          On entry, the Hermitian matrix A.  If UPLO = 'U', only the
*          upper triangular part of A is used to define the elements of
*          the Hermitian matrix.  If UPLO = 'L', only the lower
*          triangular part of A is used to define the elements of the
*          Hermitian matrix.
*
*          On exit, the lower triangle (if UPLO='L') or the upper
*          triangle (if UPLO='U') of A, including the diagonal, is
*          destroyed.
*
*  IA      (global input) INTEGER
*          A's global row index, which points to the beginning of the
*          submatrix which is to be operated on.
*
*  JA      (global input) INTEGER
*          A's global column index, which points to the beginning of
*          the submatrix which is to be operated on.
*
*  DESCA   (global and local input) INTEGER array of dimension DLEN_.
*          The array descriptor for the distributed matrix A.
*          If DESCA( CTXT_ ) is incorrect, PCHEEV cannot guarantee
*          correct error reporting.
*
*  W       (global output) REAL array, dimension (N)
*          If INFO=0, the eigenvalues in ascending order.
*
*  Z       (local output) COMPLEX array,
*          global dimension (N, N),
*          local dimension (LLD_Z, LOCc(JZ+N-1))
*          If JOBZ = 'V', then on normal exit the first M columns of Z
*          contain the orthonormal eigenvectors of the matrix
*          corresponding to the selected eigenvalues.
*          If JOBZ = 'N', then Z is not referenced.
*
*  IZ      (global input) INTEGER
*          Z's global row index, which points to the beginning of the
*          submatrix which is to be operated on.
*
*  JZ      (global input) INTEGER
*          Z's global column index, which points to the beginning of
*          the submatrix which is to be operated on.
*
*  DESCZ   (global and local input) INTEGER array of dimension DLEN_.
*          The array descriptor for the distributed matrix Z.
*          DESCZ( CTXT_ ) must equal DESCA( CTXT_ )
*
*  WORK    (local workspace/output) COMPLEX array,
*          dimension (LWORK)
*          On output, WORK(1) returns the workspace needed to guarantee
*          completion.  If the input parameters are incorrect, WORK(1)
*          may also be incorrect.
*
*          If JOBZ='N' WORK(1) = minimal workspace for eigenvalues only.
*          If JOBZ='V' WORK(1) = minimal workspace required to
*             generate all the eigenvectors.
*
*
*  LWORK   (local input) INTEGER
*          See below for definitions of variables used to define LWORK.
*          If no eigenvectors are requested (JOBZ = 'N') then
*             LWORK >= MAX( NB*( NP0+1 ), 3 ) +3*N
*          If eigenvectors are requested (JOBZ = 'V' ) then
*          the amount of workspace required:
*             LWORK >= (NP0 + NQ0 + NB)*NB + 3*N + N^2
*
*          Variable definitions:
*             NB = DESCA( MB_ ) = DESCA( NB_ ) =
*                  DESCZ( MB_ ) = DESCZ( NB_ )
*             NP0 = NUMROC( NN, NB, 0, 0, NPROW )
*             NQ0 = NUMROC( MAX( N, NB, 2 ), NB, 0, 0, NPCOL )
*
*          If LWORK = -1, the LWORK is global input and a workspace
*          query is assumed; the routine only calculates the minimum
*          size for the WORK array.  The required workspace is returned
*          as the first element of WORK and no error message is issued
*          by PXERBLA.
*
*  RWORK   (local workspace/output) COMPLEX array,
*          dimension (LRWORK)
*          On output RWORK(1) returns the
*          REAL workspace needed to
*          guarantee completion.  If the input parameters are incorrect,
*          RWORK(1) may also be incorrect.
*
*  LRWORK  (local input) INTEGER
*          Size of RWORK array.
*          If eigenvectors are desired (JOBZ = 'V') then
*             LRWORK >= 2*N + 2*N-2
*          If eigenvectors are not desired (JOBZ = 'N') then
*             LRWORK >= 2*N
*
*          If LRWORK = -1, the LRWORK is global input and a workspace
*          query is assumed; the routine only calculates the minimum
*          size for the RWORK array.  The required workspace is returned
*          as the first element of RWORK and no error message is issued
*          by PXERBLA.
*
*  INFO    (global output) INTEGER
*          = 0:  successful exit
*          < 0:  If the i-th argument is an array and the j-entry had
*                an illegal value, then INFO = -(i*100+j), if the i-th
*                argument is a scalar and had an illegal value, then
*                INFO = -i.
*          > 0:  If INFO = 1 through N, the i(th) eigenvalue did not
*                converge in CSTEQR2 after a total of 30*N iterations.
*                If INFO = N+1, then PCHEEV has detected heterogeneity
*                by finding that eigenvalues were not identical across
*                the process grid.  In this case, the accuracy of
*                the results from PCHEEV cannot be guaranteed.
*
*  Alignment requirements
*  ======================
*
*  The distributed submatrices A(IA:*, JA:*) and C(IC:IC+M-1,JC:JC+N-1)
*  must verify some alignment properties, namely the following
*  expressions should be true:
*
*  ( MB_A.EQ.NB_A.EQ.MB_Z .AND. IROFFA.EQ.IROFFZ .AND. IROFFA.EQ.0 .AND.
*    IAROW.EQ.IZROW )
*  where
*  IROFFA = MOD( IA-1, MB_A ) and ICOFFA = MOD( JA-1, NB_A ).
*
*  =====================================================================
*
*  Version 1.4 limitations:
*     DESCA(MB_) = DESCA(NB_)
*     DESCA(M_) = DESCZ(M_)
*     DESCA(N_) = DESCZ(N_)
*     DESCA(MB_) = DESCZ(MB_)
*     DESCA(NB_) = DESCZ(NB_)
*     DESCA(RSRC_) = DESCZ(RSRC_)
*
*     .. Parameters ..
      INTEGER            BLOCK_CYCLIC_2D, DLEN_, DTYPE_, CTXT_, M_, N_,
     $                   MB_, NB_, RSRC_, CSRC_, LLD_
      PARAMETER          ( BLOCK_CYCLIC_2D = 1, DLEN_ = 9, DTYPE_ = 1,
     $                   CTXT_ = 2, M_ = 3, N_ = 4, MB_ = 5, NB_ = 6,
     $                   RSRC_ = 7, CSRC_ = 8, LLD_ = 9 )
      REAL               ZERO, ONE
      PARAMETER          ( ZERO = 0.0E+0, ONE = 1.0E+0 )
      COMPLEX            CZERO, CONE
      PARAMETER          ( CZERO = ( 0.0E+0, 0.0E+0 ),
     $                   CONE = ( 1.0E+0, 0.0E+0 ) )
      INTEGER            ITHVAL
      PARAMETER          ( ITHVAL = 10 )
*     ..
*     .. Local Scalars ..
      LOGICAL            LOWER, WANTZ
      INTEGER            CONTEXTC, CSRC_A, I, IACOL, IAROW, ICOFFA,
     $                   IINFO, INDD, INDE, INDRD, INDRE, INDRWORK,
     $                   INDTAU, INDWORK, INDWORK2, IROFFA, IROFFZ,
     $                   ISCALE, IZROW, J, K, LDC, LLRWORK, LLWORK,
     $                   LRMIN, LRWMIN, LWMIN, MB_A, MB_Z, MYCOL,
     $                   MYPCOLC, MYPROWC, MYROW, NB, NB_A, NB_Z, NP0,
     $                   NPCOL, NPCOLC, NPROCS, NPROW, NPROWC, NQ0, NRC,
     $                   RSIZECSTEQR2, RSRC_A, RSRC_Z, SIZECSTEQR2,
     $                   SIZEPCHETRD, SIZEPCUNMTR
      REAL               ANRM, BIGNUM, EPS, RMAX, RMIN, SAFMIN, SIGMA,
     $                   SMLNUM
*     ..
*     .. Local Arrays ..
      INTEGER            DESCQR( 10 ), IDUM1( 3 ), IDUM2( 3 )
*     ..
*     .. External Functions ..
      LOGICAL            LSAME
      INTEGER            INDXG2P, NUMROC, SL_GRIDRESHAPE
      REAL               PCLANHE, PSLAMCH
      EXTERNAL           LSAME, INDXG2P, NUMROC, SL_GRIDRESHAPE,
     $                   PCLANHE, PSLAMCH
*     ..
*     .. External Subroutines ..
      EXTERNAL           BLACS_GRIDEXIT, BLACS_GRIDINFO, CHK1MAT,
     $                   CSTEQR2, DESCINIT, PCELGET, PCGEMR2D, PCHETRD,
     $                   PCHK1MAT, PCHK2MAT, PCLASCL, PCLASET, PCUNMTR,
     $                   PXERBLA, SCOPY, SGAMN2D, SGAMX2D, SSCAL
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC          ABS, CMPLX, ICHAR, INT, MAX, MIN, MOD, REAL,
     $                   SQRT
*     ..
*     .. Executable Statements ..
*       This is just to keep ftnchek and toolpack/1 happy
      IF( BLOCK_CYCLIC_2D*CSRC_*CTXT_*DLEN_*DTYPE_*LLD_*MB_*M_*NB_*N_*
     $    RSRC_.LT.0 )RETURN
*
*     Quick return
*
      IF( N.EQ.0 )
     $   RETURN
*
*     Test the input arguments.
*
      CALL BLACS_GRIDINFO( DESCA( CTXT_ ), NPROW, NPCOL, MYROW, MYCOL )
      INFO = 0
*
*     Initialize pointer to some safe value
*
      INDTAU = 1
      INDD = 1
      INDE = 1
      INDWORK = 1
      INDWORK2 = 1
*
      INDRE = 1
      INDRD = 1
      INDRWORK = 1
*
      WANTZ = LSAME( JOBZ, 'V' )
      IF( NPROW.EQ.-1 ) THEN
         INFO = -( 700+CTXT_ )
      ELSE IF( WANTZ ) THEN
         IF( DESCA( CTXT_ ).NE.DESCZ( CTXT_ ) ) THEN
            INFO = -( 1200+CTXT_ )
         END IF
      END IF
      IF( INFO.EQ.0 ) THEN
         CALL CHK1MAT( N, 3, N, 3, IA, JA, DESCA, 7, INFO )
         IF( WANTZ )
     $      CALL CHK1MAT( N, 3, N, 3, IZ, JZ, DESCZ, 12, INFO )
*
         IF( INFO.EQ.0 ) THEN
*
*           Get machine constants.
*
            SAFMIN = PSLAMCH( DESCA( CTXT_ ), 'Safe minimum' )
            EPS = PSLAMCH( DESCA( CTXT_ ), 'Precision' )
            SMLNUM = SAFMIN / EPS
            BIGNUM = ONE / SMLNUM
            RMIN = SQRT( SMLNUM )
            RMAX = MIN( SQRT( BIGNUM ), ONE / SQRT( SQRT( SAFMIN ) ) )
*
            NPROCS = NPROW*NPCOL
            NB_A = DESCA( NB_ )
            MB_A = DESCA( MB_ )
            NB = NB_A
            LOWER = LSAME( UPLO, 'L' )
*
            RSRC_A = DESCA( RSRC_ )
            CSRC_A = DESCA( CSRC_ )
            IROFFA = MOD( IA-1, MB_A )
            ICOFFA = MOD( JA-1, NB_A )
            IAROW = INDXG2P( 1, NB_A, MYROW, RSRC_A, NPROW )
            IACOL = INDXG2P( 1, MB_A, MYCOL, CSRC_A, NPCOL )
            NP0 = NUMROC( N+IROFFA, NB, MYROW, IAROW, NPROW )
            NQ0 = NUMROC( N+ICOFFA, NB, MYCOL, IACOL, NPCOL )
            IF( WANTZ ) THEN
               NB_Z = DESCZ( NB_ )
               MB_Z = DESCZ( MB_ )
               RSRC_Z = DESCZ( RSRC_ )
               IROFFZ = MOD( IZ-1, MB_A )
               IZROW = INDXG2P( 1, NB_A, MYROW, RSRC_Z, NPROW )
            ELSE
               IROFFZ = 0
               IZROW = 0
            END IF
*
*           COMPLEX work space for PCHETRD
*
            CALL PCHETRD( UPLO, N, A, IA, JA, DESCA, RWORK( INDD ),
     $                    RWORK( INDE ), WORK( INDTAU ),
     $                    WORK( INDWORK ), -1, IINFO )
            SIZEPCHETRD = INT( ABS( WORK( 1 ) ) )
*
*           COMPLEX work space for PCUNMTR
*
            IF( WANTZ ) THEN
               CALL PCUNMTR( 'L', UPLO, 'N', N, N, A, IA, JA, DESCA,
     $                       WORK( INDTAU ), Z, IZ, JZ, DESCZ,
     $                       WORK( INDWORK ), -1, IINFO )
               SIZEPCUNMTR = INT( ABS( WORK( 1 ) ) )
            ELSE
               SIZEPCUNMTR = 0
            END IF
*
*           REAL work space for CSTEQR2
*
            IF( WANTZ ) THEN
               RSIZECSTEQR2 = MAX( 1, 2*N-2 )
            ELSE
               RSIZECSTEQR2 = 0
            END IF
*
*           Initialize the context of the single column distributed
*           matrix required by CSTEQR2. This specific distribution
*           allows each process to do 1/pth of the work updating matrix
*           Q during CSTEQR2 and achieve some parallelization to an
*           otherwise serial subroutine.
*
            LDC = 0
            IF( WANTZ ) THEN
               CONTEXTC = SL_GRIDRESHAPE( DESCA( CTXT_ ), 0, 1, 1,
     $                    NPROCS, 1 )
               CALL BLACS_GRIDINFO( CONTEXTC, NPROWC, NPCOLC, MYPROWC,
     $                              MYPCOLC )
               NRC = NUMROC( N, NB_A, MYPROWC, 0, NPROCS )
               LDC = MAX( 1, NRC )
               CALL DESCINIT( DESCQR, N, N, NB, NB, 0, 0, CONTEXTC, LDC,
     $                        INFO )
            END IF
*
*           COMPLEX work space for CSTEQR2
*
            IF( WANTZ ) THEN
               SIZECSTEQR2 = N*LDC
            ELSE
               SIZECSTEQR2 = 0
            END IF
*
*           Set up pointers into the WORK array
*
            INDTAU = 1
            INDD = INDTAU + N
            INDE = INDD + N
            INDWORK = INDE + N
            INDWORK2 = INDWORK + N*LDC
            LLWORK = LWORK - INDWORK + 1
*
*           Set up pointers into the RWORK array
*
            INDRE = 1
            INDRD = INDRE + N
            INDRWORK = INDRD + N
            LLRWORK = LRWORK - INDRWORK + 1
*
*           Compute the total amount of space needed
*
            LRWMIN = 2*N + RSIZECSTEQR2
            LWMIN = 3*N + MAX( SIZEPCHETRD, SIZEPCUNMTR, SIZECSTEQR2 )
*
         END IF
         IF( INFO.EQ.0 ) THEN
            IF( .NOT.( WANTZ .OR. LSAME( JOBZ, 'N' ) ) ) THEN
               INFO = -1
            ELSE IF( .NOT.( LOWER .OR. LSAME( UPLO, 'U' ) ) ) THEN
               INFO = -2
            ELSE IF( LWORK.LT.LWMIN .AND. LWORK.NE.-1 ) THEN
               INFO = -14
            ELSE IF( LRWORK.LT.LRWMIN .AND. LRWORK.NE.-1 ) THEN
               INFO = -16
            ELSE IF( IROFFA.NE.0 ) THEN
               INFO = -5
            ELSE IF( DESCA( MB_ ).NE.DESCA( NB_ ) ) THEN
               INFO = -( 700+NB_ )
            END IF
            IF( WANTZ ) THEN
               IF( IROFFA.NE.IROFFZ ) THEN
                  INFO = -10
               ELSE IF( IAROW.NE.IZROW ) THEN
                  INFO = -10
               ELSE IF( DESCA( M_ ).NE.DESCZ( M_ ) ) THEN
                  INFO = -( 1200+M_ )
               ELSE IF( DESCA( N_ ).NE.DESCZ( N_ ) ) THEN
                  INFO = -( 1200+N_ )
               ELSE IF( DESCA( MB_ ).NE.DESCZ( MB_ ) ) THEN
                  INFO = -( 1200+MB_ )
               ELSE IF( DESCA( NB_ ).NE.DESCZ( NB_ ) ) THEN
                  INFO = -( 1200+NB_ )
               ELSE IF( DESCA( RSRC_ ).NE.DESCZ( RSRC_ ) ) THEN
                  INFO = -( 1200+RSRC_ )
               ELSE IF( DESCA( CTXT_ ).NE.DESCZ( CTXT_ ) ) THEN
                  INFO = -( 1200+CTXT_ )
               END IF
            END IF
         END IF
         IF( WANTZ ) THEN
            IDUM1( 1 ) = ICHAR( 'V' )
         ELSE
            IDUM1( 1 ) = ICHAR( 'N' )
         END IF
         IDUM2( 1 ) = 1
         IF( LOWER ) THEN
            IDUM1( 2 ) = ICHAR( 'L' )
         ELSE
            IDUM1( 2 ) = ICHAR( 'U' )
         END IF
         IDUM2( 2 ) = 2
         IF( LWORK.EQ.-1 ) THEN
            IDUM1( 3 ) = -1
         ELSE
            IDUM1( 3 ) = 1
         END IF
         IDUM2( 3 ) = 3
         IF( WANTZ ) THEN
            CALL PCHK2MAT( N, 3, N, 3, IA, JA, DESCA, 7, N, 3, N, 3, IZ,
     $                     JZ, DESCZ, 12, 3, IDUM1, IDUM2, INFO )
         ELSE
            CALL PCHK1MAT( N, 3, N, 3, IA, JA, DESCA, 7, 3, IDUM1,
     $                     IDUM2, INFO )
         END IF
         WORK( 1 ) = CMPLX( LWMIN )
         RWORK( 1 ) = REAL( LRWMIN )
      END IF
*
      IF( INFO.NE.0 ) THEN
         CALL PXERBLA( DESCA( CTXT_ ), 'PCHEEV', -INFO )
         IF( WANTZ )
     $      CALL BLACS_GRIDEXIT( CONTEXTC )
         RETURN
      ELSE IF( LWORK.EQ.-1 .OR. LRWORK.EQ.-1 ) THEN
         IF( WANTZ )
     $      CALL BLACS_GRIDEXIT( CONTEXTC )
         RETURN
      END IF
*
*     Scale matrix to allowable range, if necessary.
*
      ISCALE = 0
*
      ANRM = PCLANHE( 'M', UPLO, N, A, IA, JA, DESCA,
     $       RWORK( INDRWORK ) )
*
*
      IF( ANRM.GT.ZERO .AND. ANRM.LT.RMIN ) THEN
         ISCALE = 1
         SIGMA = RMIN / ANRM
      ELSE IF( ANRM.GT.RMAX ) THEN
         ISCALE = 1
         SIGMA = RMAX / ANRM
      END IF
*
      IF( ISCALE.EQ.1 ) THEN
         CALL PCLASCL( UPLO, ONE, SIGMA, N, N, A, IA, JA, DESCA, IINFO )
      END IF
*
*     Reduce Hermitian matrix to tridiagonal form.
*
      CALL PCHETRD( UPLO, N, A, IA, JA, DESCA, RWORK( INDRD ),
     $              RWORK( INDRE ), WORK( INDTAU ), WORK( INDWORK ),
     $              LLWORK, IINFO )
*
*     Copy the values of D, E to all processes.
*
      DO 10 I = 1, N
         CALL PCELGET( 'A', ' ', WORK( INDD+I-1 ), A, I+IA-1, I+JA-1,
     $                 DESCA )
         RWORK( INDRD+I-1 ) = REAL( WORK( INDD+I-1 ) )
   10 CONTINUE
      IF( LSAME( UPLO, 'U' ) ) THEN
         DO 20 I = 1, N - 1
            CALL PCELGET( 'A', ' ', WORK( INDE+I-1 ), A, I+IA-1, I+JA,
     $                    DESCA )
            RWORK( INDRE+I-1 ) = REAL( WORK( INDE+I-1 ) )
   20    CONTINUE
      ELSE
         DO 30 I = 1, N - 1
            CALL PCELGET( 'A', ' ', WORK( INDE+I-1 ), A, I+IA, I+JA-1,
     $                    DESCA )
            RWORK( INDRE+I-1 ) = REAL( WORK( INDE+I-1 ) )
   30    CONTINUE
      END IF
*
      IF( WANTZ ) THEN
*
         CALL PCLASET( 'Full', N, N, CZERO, CONE, WORK( INDWORK ), 1, 1,
     $                 DESCQR )
*
*        CSTEQR2 is a modified version of LAPACK's CSTEQR.  The
*        modifications allow each process to perform partial updates
*        to matrix Q.
*
         CALL CSTEQR2( 'I', N, RWORK( INDRD ), RWORK( INDRE ),
     $                 WORK( INDWORK ), LDC, NRC, RWORK( INDRWORK ),
     $                 INFO )
*
         CALL PCGEMR2D( N, N, WORK( INDWORK ), 1, 1, DESCQR, Z, IA, JA,
     $                  DESCZ, CONTEXTC )
*
         CALL PCUNMTR( 'L', UPLO, 'N', N, N, A, IA, JA, DESCA,
     $                 WORK( INDTAU ), Z, IZ, JZ, DESCZ,
     $                 WORK( INDWORK ), LLWORK, IINFO )
*
      ELSE
*
         CALL CSTEQR2( 'N', N, RWORK( INDRD ), RWORK( INDRE ),
     $                 WORK( INDWORK ), 1, 1, RWORK( INDRWORK ), INFO )
      END IF
*
*     Copy eigenvalues from workspace to output array
*
      CALL SCOPY( N, RWORK( INDD ), 1, W, 1 )
*
*     If matrix was scaled, then rescale eigenvalues appropriately.
*
      IF( ISCALE.EQ.1 ) THEN
         CALL SSCAL( N, ONE / SIGMA, W, 1 )
      END IF
*
      WORK( 1 ) = REAL( LWMIN )
*
*     Free up resources
*
      IF( WANTZ ) THEN
         CALL BLACS_GRIDEXIT( CONTEXTC )
      END IF
*
*     Compare every ith eigenvalue, or all if there are only a few,
*     across the process grid to check for heterogeneity.
*
      IF( N.LE.ITHVAL ) THEN
         J = N
         K = 1
      ELSE
         J = N / ITHVAL
         K = ITHVAL
      END IF
*
      LRMIN = INT( RWORK( 1 ) )
      INDTAU = 0
      INDE = INDTAU + J
      DO 40 I = 1, J
         RWORK( I+INDTAU ) = W( ( I-1 )*K+1 )
         RWORK( I+INDE ) = W( ( I-1 )*K+1 )
   40 CONTINUE
*
      CALL SGAMN2D( DESCA( CTXT_ ), 'All', ' ', J, 1, RWORK( 1+INDTAU ),
     $              J, 1, 1, -1, -1, 0 )
      CALL SGAMX2D( DESCA( CTXT_ ), 'All', ' ', J, 1, RWORK( 1+INDE ),
     $              J, 1, 1, -1, -1, 0 )
*
      DO 50 I = 1, J
         IF( INFO.EQ.0 .AND. ( RWORK( I+INDTAU )-RWORK( I+INDE ).NE.
     $       ZERO ) ) THEN
            INFO = N + 1
         END IF
   50 CONTINUE
      RWORK( 1 ) = LRMIN
*
      RETURN
*
*     End of PCHEEV
*
      END
