SUBROUTINE PZLAMR1D( N, A, IA, JA, DESCA, B, IB, JB, DESCB )
*
* -- ScaLAPACK routine (version 1.7) --
* University of Tennessee, Knoxville, Oak Ridge National Laboratory,
* and University of California, Berkeley.
* October 15, 1999
*
* .. Scalar Arguments ..
INTEGER IA, IB, JA, JB, N
* ..
* .. Array Arguments ..
INTEGER DESCA( * ), DESCB( * )
COMPLEX*16 A( * ), B( * )
* ..
*
* Bugs
* ====
*
* I am not sure that this works correctly when IB and JB are not equal
* to 1. Indeed, I suspect that IB should always be set to 1 or ignored
* with 1 used in its place.
*
* PZLAMR1D has not been tested except withint the contect of
* PZHEPTRD, the prototype reduction to tridiagonal form code.
*
* Purpose
*
* =======
*
* PZLAMR1D redistributes a one-dimensional row vector from one data
* decomposition to another.
*
* This is an auxiliary routine called by PZHETRD to redistribute D, E
* and TAU.
*
* Notes
* =====
*
* Although all processes call PZGEMR2D, only the processes that own
* the first column of A send data and only processes that own the
* first column of B receive data. The calls to ZGEBS2D/ZGEBR2D
* spread the data down.
*
* Arguments
* =========
*
* N (global input) INTEGER
* The size of the matrix to be transposed.
*
* A (local output) COMPLEX*16 pointer into the
* local memory to an array of dimension (LOCc(JA+N-1)).
* On output, A is replicated across all processes in
* this processor column.
*
* 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.
*
* B (local input/local output) COMPLEX*16 pointer into the
* local memory to an array of dimension (LOCc(JB+N-1)).
*
* IB (global input) INTEGER
* B's global row index, NOT USED
*
* JB (global input) INTEGER
* B's global column index, which points to the beginning of
* the submatrix which is to be operated on.
*
* DESCB (global and local input) INTEGER array of dimension DLEN_.
* The array descriptor for the distributed matrix B.
*
* WORK (local workspace) COMPLEX*16 array, dimension ( LWORK )
*
* LWORK (local input) INTEGER
* The dimension of the array WORK.
* LWORK is local input and must be at least
* LWORK >= NB * NUMROC( N, 1, 0, 0, NPROW )
*
* =====================================================================
*
* .. 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 )
* ..
* .. Local Scalars ..
INTEGER I, ICTXT, MYCOL, MYROW, NPCOL, NPROW, NQ
* ..
* .. Local Arrays ..
INTEGER DESCAA( DLEN_ ), DESCBB( DLEN_ )
* ..
* .. External Subroutines ..
EXTERNAL BLACS_GRIDINFO, PZGEMR2D, ZGEBR2D, ZGEBS2D
* ..
* .. External Functions ..
INTEGER NUMROC
EXTERNAL NUMROC
* ..
* .. 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 possible
*
IF( N.LE.0 )
$ RETURN
*
DO 10 I = 1, DLEN_
DESCAA( I ) = DESCA( I )
DESCBB( I ) = DESCB( I )
10 CONTINUE
*
DESCAA( M_ ) = 1
DESCBB( M_ ) = 1
DESCAA( LLD_ ) = 1
DESCBB( LLD_ ) = 1
*
ICTXT = DESCB( CTXT_ )
CALL PZGEMR2D( 1, N, A, IA, JA, DESCAA, B, IB, JB, DESCBB, ICTXT )
*
CALL BLACS_GRIDINFO( ICTXT, NPROW, NPCOL, MYROW, MYCOL )
NQ = NUMROC( N, DESCB( NB_ ), MYCOL, 0, NPCOL )
*
IF( MYROW.EQ.0 ) THEN
CALL ZGEBS2D( ICTXT, 'C', ' ', NQ, 1, B, NQ )
ELSE
CALL ZGEBR2D( ICTXT, 'C', ' ', NQ, 1, B, NQ, 0, MYCOL )
END IF
*
RETURN
*
* End of PZLAMR1D
*
END