..
     .. Array Arguments ..
     ..
  Purpose
  =======
  PZLAPIV applies either P (permutation matrix indicated by IPIV)
  or inv( P ) to a general M-by-N distributed matrix
  sub( A ) = A(IA:IA+M-1,JA:JA+N-1), resulting in row or column
  pivoting. The pivot vector may be distributed across a process row
  or a column. The pivot vector should be aligned with the distributed
  matrix A. This routine will transpose the pivot vector if necessary.
  For example if the row pivots should be applied to the columns of
  sub( A ), pass ROWCOL='C' and PIVROC='C'.
  Notes
  =====
  Each global data object is described by an associated description
  vector.  This vector stores the information required to establish
  the mapping between an object element and its corresponding process
  and memory location.
  Let A be a generic term for any 2D block cyclicly distributed array.
  Such a global array has an associated description vector DESCA.
  In the following comments, the character _ should be read as
  "of the global array".
  NOTATION        STORED IN      EXPLANATION
  --------------- -------------- --------------------------------------
  DTYPE_A(global) DESCA( DTYPE_ )The descriptor type.  In this case,
                                 DTYPE_A = 1.
  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 global
                                 array A.
  N_A    (global) DESCA( N_ )    The number of columns in the global
                                 array A.
  MB_A   (global) DESCA( MB_ )   The blocking factor used to distribute
                                 the rows of the array.
  NB_A   (global) DESCA( NB_ )   The blocking factor used to distribute
                                 the columns of the array.
  RSRC_A (global) DESCA( RSRC_ ) The process row over which the first
                                 row of the array A is distributed.
  CSRC_A (global) DESCA( CSRC_ ) The process column over which the
                                 first column of the array A is
                                 distributed.
  LLD_A  (local)  DESCA( LLD_ )  The leading dimension of the local
                                 array.  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 ).
  An upper bound for these quantities may be computed by:
          LOCr( M ) <= ceil( ceil(M/MB_A)/NPROW )*MB_A
          LOCc( N ) <= ceil( ceil(N/NB_A)/NPCOL )*NB_A
  Restrictions
  ============
  IPIV must always be a distributed vector (not a matrix).  Thus:
  IF( ROWPIV .EQ. 'C' ) THEN
     JP must be 1
  ELSE
     IP must be 1
  END IF
  The following restrictions apply when IPIV must be transposed:
  IF( ROWPIV.EQ.'C' .AND. PIVROC.EQ.'C') THEN
      DESCIP(MB_) must equal DESCA(NB_)
  ELSE IF( ROWPIV.EQ.'R" .AND. PIVROC.EQ.'R') THEN
      DESCIP(NB_) must equal DESCA(MB_)
  END IF
  Arguments
  =========
  DIREC   (global input) CHARACTER*1
          Specifies in which order the permutation is applied:
            = 'F' (Forward) Applies pivots Forward from top of matrix.
                  Computes P*sub( A ).
            = 'B' (Backward) Applies pivots Backward from bottom of
                  matrix. Computes inv( P )*sub( A ).
  ROWCOL  (global input) CHARACTER*1
          Specifies if the rows or columns are to be permuted:
             = 'R' Rows will be permuted,
             = 'C' Columns will be permuted.
  PIVROC  (global input) CHARACTER*1
          Specifies whether IPIV is distributed over a process row
          or column:
          = 'R' IPIV distributed over a process row
          = 'C' IPIV distributed over a process column
  M       (global input) INTEGER
          The number of rows to be operated on, i.e. the number of
          rows of the distributed submatrix sub( A ). M >= 0.
  N       (global input) INTEGER
          The number of columns to be operated on, i.e. the number of
          columns of the distributed submatrix sub( A ). N >= 0.
  A       (local input/local output) COMPLEX*16 pointer into the
          local memory to an array of dimension (LLD_A, LOCc(JA+N-1)).
          On entry, this array contains the local pieces of the
          distributed submatrix sub( A ) to which the row or column
          interchanges will be applied. On exit, the local pieces
          of the permuted distributed submatrix.
  IA      (global input) INTEGER
          The row index in the global array A indicating the first
          row of sub( A ).
  JA      (global input) INTEGER
          The column index in the global array A indicating the
          first column of sub( A ).
  DESCA   (global and local input) INTEGER array of dimension DLEN_.
          The array descriptor for the distributed matrix A.
  IPIV    (local input) INTEGER array, dimension (LIPIV) where LIPIV is
          when ROWCOL='R' or 'r':
             >= LOCr( IA+M-1 ) + MB_A      if PIVROC='C' or 'c',
             >= LOCc( M + MOD(JP-1,NB_P) ) if PIVROC='R' or 'r', and,
          when ROWCOL='C' or 'c':
             >= LOCr( N + MOD(IP-1,MB_P) ) if PIVROC='C' or 'c',
             >= LOCc( JA+N-1 ) + NB_A      if PIVROC='R' or 'r'.
          This array contains the pivoting information. IPIV(i) is the
          global row (column), local row (column) i was swapped with.
          When ROWCOL='R' or 'r' and PIVROC='C' or 'c', or ROWCOL='C'
          or 'c' and PIVROC='R' or 'r', the last piece of this array of
          size MB_A (resp. NB_A) is used as workspace. In those cases,
          this array is tied to the distributed matrix A.
  IP      (global input) INTEGER
          The row index in the global array P indicating the first
          row of sub( P ).
  JP      (global input) INTEGER
          The column index in the global array P indicating the
          first column of sub( P ).
  DESCIP  (global and local input) INTEGER array of dimension DLEN_.
          The array descriptor for the distributed vector IPIV.
  IWORK   (local workspace) INTEGER array, dimension (LDW)
          where LDW is equal to the workspace necessary for
          transposition, and the storage of the tranposed IPIV:
          Let LCM be the least common multiple of NPROW and NPCOL.
          IF( ROWCOL.EQ.'R' .AND. PIVROC.EQ.'R' ) THEN
             IF( NPROW.EQ.NPCOL ) THEN
                LDW = LOCr( N_P + MOD(JP-1, NB_P) ) + NB_P
             ELSE
                LDW = LOCr( N_P + MOD(JP-1, NB_P) ) +
                      NB_P * CEIL( CEIL(LOCc(N_P)/NB_P) / (LCM/NPCOL) )
             END IF
          ELSE IF( ROWCOL.EQ.'C' .AND. PIVROC.EQ.'C' ) THEN
             IF( NPROW.EQ.NPCOL ) THEN
                LDW = LOCc( M_P + MOD(IP-1, MB_P) ) + MB_P
             ELSE
                LDW = LOCc( M_P + MOD(IP-1, MB_P) ) +
                      MB_P * CEIL( CEIL(LOCr(M_P)/MB_P) / (LCM/NPROW) )
             END IF
          ELSE
             IWORK is not referenced.
          END IF
  =====================================================================
     .. Parameters ..