SUBROUTINE PDLAMVE( UPLO, M, N, A, IA, JA, DESCA, B, IB, JB, $ DESCB, DWORK ) * * Contribution from the Department of Computing Science and HPC2N, * Umea University, Sweden * * -- ScaLAPACK auxiliary routine (version 2.0.2) -- * Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver * May 1 2012 * IMPLICIT NONE * * .. Scalar Arguments .. CHARACTER UPLO INTEGER IA, IB, JA, JB, M, N * .. * .. Array Arguments .. INTEGER DESCA( * ), DESCB( * ) DOUBLE PRECISION A( * ), B( * ), DWORK( * ) * .. * * Purpose * ======= * * PDLAMVE copies all or part of a distributed matrix A to another * distributed matrix B. There is no alignment assumptions at all * except that A and B are of the same size. * * 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 * * Arguments * ========= * * UPLO (global input) CHARACTER * Specifies the part of the distributed matrix sub( A ) to be * copied: * = 'U': Upper triangular part is copied; the strictly * lower triangular part of sub( A ) is not referenced; * = 'L': Lower triangular part is copied; the strictly * upper triangular part of sub( A ) is not referenced; * Otherwise: All of the matrix sub( A ) is copied. * * 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) DOUBLE PRECISION pointer into the local memory * to an array of dimension (LLD_A, LOCc(JA+N-1) ). This array * contains the local pieces of the distributed matrix sub( A ) * to be copied from. * * 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. * * B (local output) DOUBLE PRECISION pointer into the local memory * to an array of dimension (LLD_B, LOCc(JB+N-1) ). This array * contains on exit the local pieces of the distributed matrix * sub( B ). * * IB (global input) INTEGER * The row index in the global array B indicating the first * row of sub( B ). * * JB (global input) INTEGER * The column index in the global array B indicating the * first column of sub( B ). * * DESCB (global and local input) INTEGER array of dimension DLEN_. * The array descriptor for the distributed matrix B. * * DWORK (local workspace) DOUBLE PRECISION array * If UPLO = 'U' or UPLO = 'L' and number of processors > 1, * the length of DWORK is at least as large as the length of B. * Otherwise, DWORK is not referenced. * * ===================================================================== * * .. Parameters .. INTEGER BLOCK_CYCLIC_2D, CSRC_, CTXT_, DLEN_, DTYPE_, $ LLD_, MB_, M_, NB_, N_, RSRC_ 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 .. LOGICAL UPPER, LOWER, FULL INTEGER ICTXT, NPROW, NPCOL, MYROW, MYCOL, MYPROC, $ NPROCS, AROWS, ACOLS, K, SPROC, SRSRC, SCSRC, $ RPROC, RRSRC, RCSRC, COUNT, J, I, IIA, JJA, $ IIB, JJB, BRSRC, BCSRC, RAROWS, RACOLS, $ INDEX, IDUM, NUMREC, NUMSND * .. * .. External Subroutines .. EXTERNAL DLAMOV, INFOG2L * .. * .. External Functions .. LOGICAL LSAME INTEGER ICEIL, NUMROC, INDXL2G EXTERNAL ICEIL, LSAME, NUMROC, INDXL2G * .. * .. Intrinsic Functions .. INTRINSIC MIN, MOD * .. * .. Executable Statements .. * * Find underlying mesh properties. * ICTXT = DESCA( CTXT_ ) CALL BLACS_GRIDINFO( ICTXT, NPROW, NPCOL, MYROW, MYCOL ) * * Decode input parameters. * UPPER = LSAME( UPLO, 'U' ) IF( .NOT. UPPER ) LOWER = LSAME( UPLO, 'L' ) FULL = (.NOT. UPPER) .AND. (.NOT. LOWER) * * Assign indiviual numbers based on column major ordering. * NPROCS = NPROW*NPCOL * * Do redistribution operation. * IF( NPROCS.EQ.1 ) THEN CALL DLAMOV( UPLO, M, N, A((JA-1)*DESCA(LLD_)+IA), $ DESCA(LLD_), B((JB-1)*DESCB(LLD_)+IB), $ DESCB(LLD_) ) ELSEIF( FULL ) THEN CALL PDGEMR2D( M, N, A, IA, JA, DESCA, B, IB, JB, DESCB, $ ICTXT ) ELSE CALL PDGEMR2D( M, N, A, IA, JA, DESCA, DWORK, IB, JB, DESCB, $ ICTXT ) CALL PDLACPY( UPLO, M, N, DWORK, IB, JB, DESCB, B, IB, JB, $ DESCB ) END IF * RETURN * * End of PDLAMVE * END