Routine: PSLACPY()  File: SRC\pslacpy.f

 
 
# lines: 231
  # code: 231
  # comment: 0
  # blank:0
# Variables:32
# Callers:4
# Callings:1
# Words:79
# Keywords:51
 

 

..
     .. Array Arguments ..
     ..
  Purpose
  =======
  PSLACPY copies all or part of a distributed matrix A to another
  distributed matrix B.  No communication is performed, PSLACPY
  performs a local copy sub( A ) := sub( B ), where sub( A ) denotes
  A(IA:IA+M-1,JA:JA+N-1) and sub( B ) denotes B(IB:IB+M-1,JB:JB+N-1).
  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) REAL 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) REAL 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 ) set as follows:
          if UPLO = 'U', B(IB+i-1,JB+j-1) = A(IA+i-1,JA+j-1),
                         1<=i<=j, 1<=j<=N;
          if UPLO = 'L', B(IB+i-1,JB+j-1) = A(IA+i-1,JA+j-1),
                         j<=i<=M, 1<=j<=N;
          otherwise,     B(IB+i-1,JB+j-1) = A(IA+i-1,JA+j-1),
                         1<=i<=M, 1<=j<=N.
  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.
  =====================================================================
     .. Parameters ..

 
Display dynamic version Find AutoScroll Reload FontSize: - + Hide Comments Hide Blanks Frame FullScreen MailPrint

 
001        SUBROUTINE PSLACPY( UPLO , M , N , A , IA , JA , DESCA , B , IB , JB ,
002       $DESCB )
003  
004  *     -- ScaLAPACK auxiliary routine(version 1.7) --
005  *     University of Tennessee , Knoxville , Oak Ridge National Laboratory ,
006  *     and University of California , Berkeley.
007  *     May 1 , 1997
008  
009  *     .. Scalar Arguments ..
010        CHARACTER UPLO
011        INTEGER IA , IB , JA , JB , M , N
012        INTEGER BLOCK_CYCLIC_2D , CSRC_ , CTXT_ , DLEN_ , DTYPE_ ,
013       $LLD_ , MB_ , M_ , NB_ , N_ , RSRC_
014        PARAMETER( BLOCK_CYCLIC_2D = 1 , DLEN_ = 9 , DTYPE_ = 1 ,
015       $CTXT_ = 2 , M_ = 3 , N_ = 4 , MB_ = 5 , NB_ = 6 ,
016       $RSRC_ = 7 , CSRC_ = 8 , LLD_ = 9 )
017  *     ..
018  *     .. Local Scalars ..
019        INTEGER I , IAA , IBB , IBLK , IN , ITMP , J , JAA , JBB ,
020       $JBLK , JN , JTMP
021  *     ..
022  *     .. External Subroutines ..
023        EXTERNAL PSLACP2  
024  *     ..
025  *     .. External Functions ..
026        LOGICAL LSAME
027        INTEGER ICEIL
028        EXTERNAL ICEIL , LSAME
029  *     ..
030  *     .. Intrinsic Functions ..
031        INTRINSIC MIN , MOD
032  *     ..
033  *     .. Executable Statements ..
034  
035        IF( M.EQ.0 .OR. N.EQ.0 )
036       $    RETURN
037  
038            IN = MIN( ICEIL( IA , DESCA( MB_ ) ) * DESCA( MB_ ) , IA + M - 1 )
039            JN = MIN( ICEIL( JA , DESCA( NB_ ) ) * DESCA( NB_ ) , JA + N - 1 )
040  
041            IF( M.LE.( DESCA( MB_ ) - MOD( IA - 1 , DESCA( MB_ ) ) ) .OR.
042       $    N.LE.( DESCA( NB_ ) - MOD( JA - 1 , DESCA( NB_ ) ) ) ) THEN
043            CALL PSLACP2 ( UPLO , M , N , A , IA , JA , DESCA ,
044       $    B , IB , JB , DESCB )
045        ELSE
046  
047            IF( LSAME( UPLO , 'U' ) ) THEN
048                CALL PSLACP2 ( UPLO , IN - IA + 1 , N , A , IA , JA , DESCA ,
049       $        B , IB , JB , DESCB )
050                DO 10 I = IN + 1 , IA + M - 1 , DESCA( MB_ )
051                    ITMP = I - IA
052                    IBLK = MIN( DESCA( MB_ ) , M - ITMP )
053                    IBB = IB + ITMP
054                    JBB = JB + ITMP
055                    JAA = JA + ITMP
056                    CALL PSLACP2 ( UPLO , IBLK , N - ITMP , A , I , JAA , DESCA ,
057       $            B , IBB , JBB , DESCB )
058     10         CONTINUE
059            ELSE IF( LSAME( UPLO , 'L' ) ) THEN
060                CALL PSLACP2 ( UPLO , M , JN - JA + 1 , A , IA , JA , DESCA ,
061       $        B , IB , JB , DESCB )
062                DO 20 J = JN + 1 , JA + N - 1 , DESCA( NB_ )
063                    JTMP = J - JA
064                    JBLK = MIN( DESCA( NB_ ) , N - JTMP )
065                    IBB = IB + JTMP
066                    JBB = JB + JTMP
067                    IAA = IA + JTMP
068                    CALL PSLACP2 ( UPLO , M - JTMP , JBLK , A , IAA , J , DESCA ,
069       $            B , IBB , JBB , DESCB )
070     20         CONTINUE
071            ELSE
072                IF( M.LE.N ) THEN
073                    CALL PSLACP2 ( UPLO , IN - IA + 1 , N , A , IA , JA , DESCA ,
074       $            B , IB , JB , DESCB )
075                    DO 30 I = IN + 1 , IA + M - 1 , DESCA( MB_ )
076                        ITMP = I - IA
077                        IBLK = MIN( DESCA( MB_ ) , M - ITMP )
078                        IBB = IB + ITMP
079                        CALL PSLACP2 ( UPLO , IBLK , N , A , I , JA , DESCA ,
080       $                B , IBB , JB , DESCB )
081     30             CONTINUE
082                ELSE
083                    CALL PSLACP2 ( UPLO , M , JN - JA + 1 , A , IA , JA , DESCA ,
084       $            B , IB , JB , DESCB )
085                    DO 40 J = JN + 1 , JA + N - 1 , DESCA( NB_ )
086                        JTMP = J - JA
087                        JBLK = MIN( DESCA( NB_ ) , N - JTMP )
088                        JBB = JB + JTMP
089                        CALL PSLACP2 ( UPLO , M , JBLK , A , IA , J , DESCA ,
090       $                B , IB , JBB , DESCB )
091     40             CONTINUE
092                END IF
093            END IF
094  
095        END IF
096  
097        RETURN
098  
099  *     End of PSLACPY
100  
101        END