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ScaLAPACK
2.0.2
ScaLAPACK: Scalable Linear Algebra PACKage
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ScaLAPACK
2.0.2
ScaLAPACK: Scalable Linear Algebra PACKage
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#include "pblas.h"#include "PBpblas.h"#include "PBtools.h"#include "PBblacs.h"#include "PBblas.h"Go to the source code of this file.
Functions/Subroutines | |
| void | psgeadd_ (F_CHAR_T TRANS, int *M, int *N, float *ALPHA, float *A, int *IA, int *JA, int *DESCA, float *BETA, float *C, int *IC, int *JC, int *DESCC) |
| void psgeadd_ | ( | F_CHAR_T | TRANS, |
| int * | M, | ||
| int * | N, | ||
| float * | ALPHA, | ||
| float * | A, | ||
| int * | IA, | ||
| int * | JA, | ||
| int * | DESCA, | ||
| float * | BETA, | ||
| float * | C, | ||
| int * | IC, | ||
| int * | JC, | ||
| int * | DESCC | ||
| ) |
Definition at line 26 of file psgeadd_.c.
{
/*
* Purpose
* =======
*
* PSGEADD adds a matrix to another
*
* sub( C ) := beta*sub( C ) + alpha*op( sub( A ) )
*
* where
*
* sub( C ) denotes C(IC:IC+M-1,JC:JC+N-1), and, op( X ) is one of
*
* op( X ) = X or op( X ) = X'.
*
* Thus, op( sub( A ) ) denotes A(IA:IA+M-1,JA:JA+N-1) if TRANS = 'N',
* A(IA:IA+N-1,JA:JA+M-1)' if TRANS = 'T',
* A(IA:IA+N-1,JA:JA+M-1)' if TRANS = 'C'.
*
* Alpha and beta are scalars, sub( C ) and op( sub( A ) ) are m by n
* submatrices.
*
* 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 DESC_A:
*
* NOTATION STORED IN EXPLANATION
* ---------------- --------------- ------------------------------------
* DTYPE_A (global) DESCA[ DTYPE_ ] The descriptor type.
* CTXT_A (global) DESCA[ CTXT_ ] The BLACS context handle, indicating
* the NPROW x NPCOL BLACS process grid
* A is distributed over. The context
* itself is global, but the handle
* (the integer value) may vary.
* M_A (global) DESCA[ M_ ] The number of rows in the distribu-
* ted matrix A, M_A >= 0.
* N_A (global) DESCA[ N_ ] The number of columns in the distri-
* buted matrix A, N_A >= 0.
* IMB_A (global) DESCA[ IMB_ ] The number of rows of the upper left
* block of the matrix A, IMB_A > 0.
* INB_A (global) DESCA[ INB_ ] The number of columns of the upper
* left block of the matrix A,
* INB_A > 0.
* MB_A (global) DESCA[ MB_ ] The blocking factor used to distri-
* bute the last M_A-IMB_A rows of A,
* MB_A > 0.
* NB_A (global) DESCA[ NB_ ] The blocking factor used to distri-
* bute the last N_A-INB_A columns of
* A, NB_A > 0.
* RSRC_A (global) DESCA[ RSRC_ ] The process row over which the first
* row of the matrix A is distributed,
* NPROW > RSRC_A >= 0.
* CSRC_A (global) DESCA[ CSRC_ ] The process column over which the
* first column of A is distributed.
* NPCOL > CSRC_A >= 0.
* LLD_A (local) DESCA[ LLD_ ] The leading dimension of the local
* array storing the local blocks of
* the distributed matrix A,
* IF( Lc( 1, N_A ) > 0 )
* LLD_A >= MAX( 1, Lr( 1, M_A ) )
* ELSE
* LLD_A >= 1.
*
* Let K be the number of rows of a matrix A starting at the global in-
* dex IA,i.e, A( IA:IA+K-1, : ). Lr( IA, K ) denotes the number of rows
* that the process of row coordinate MYROW ( 0 <= MYROW < NPROW ) would
* receive if these K rows were distributed over NPROW processes. If K
* is the number of columns of a matrix A starting at the global index
* JA, i.e, A( :, JA:JA+K-1, : ), Lc( JA, K ) denotes the number of co-
* lumns that the process MYCOL ( 0 <= MYCOL < NPCOL ) would receive if
* these K columns were distributed over NPCOL processes.
*
* The values of Lr() and Lc() may be determined via a call to the func-
* tion PB_Cnumroc:
* Lr( IA, K ) = PB_Cnumroc( K, IA, IMB_A, MB_A, MYROW, RSRC_A, NPROW )
* Lc( JA, K ) = PB_Cnumroc( K, JA, INB_A, NB_A, MYCOL, CSRC_A, NPCOL )
*
* Arguments
* =========
*
* TRANS (global input) CHARACTER*1
* On entry, TRANS specifies the form of op( sub( A ) ) to be
* used in the matrix addition as follows:
*
* TRANS = 'N' or 'n' op( sub( A ) ) = sub( A ),
*
* TRANS = 'T' or 't' op( sub( A ) ) = sub( A )',
*
* TRANS = 'C' or 'c' op( sub( A ) ) = sub( A )'.
*
* M (global input) INTEGER
* On entry, M specifies the number of rows of the submatrix
* sub( C ) and the number of columns of the submatrix sub( A ).
* M must be at least zero.
*
* N (global input) INTEGER
* On entry, N specifies the number of columns of the submatrix
* sub( C ) and the number of rows of the submatrix sub( A ). N
* must be at least zero.
*
* ALPHA (global input) REAL
* On entry, ALPHA specifies the scalar alpha. When ALPHA is
* supplied as zero then the local entries of the array A
* corresponding to the entries of the submatrix sub( A ) need
* not be set on input.
*
* A (local input) REAL array
* On entry, A is an array of dimension (LLD_A, Ka), where Ka is
* at least Lc( 1, JA+M-1 ). Before entry, this array contains
* the local entries of the matrix A.
*
* IA (global input) INTEGER
* On entry, IA specifies A's global row index, which points to
* the beginning of the submatrix sub( A ).
*
* JA (global input) INTEGER
* On entry, JA specifies A's global column index, which points
* to the beginning of the submatrix sub( A ).
*
* DESCA (global and local input) INTEGER array
* On entry, DESCA is an integer array of dimension DLEN_. This
* is the array descriptor for the matrix A.
*
* BETA (global input) REAL
* On entry, BETA specifies the scalar beta. When BETA is
* supplied as zero then the local entries of the array C
* corresponding to the entries of the submatrix sub( C ) need
* not be set on input.
*
* C (local input/local output) REAL array
* On entry, C is an array of dimension (LLD_C, Kc), where Kc is
* at least Lc( 1, JC+N-1 ). Before entry, this array contains
* the local entries of the matrix C.
* On exit, the entries of this array corresponding to the local
* entries of the submatrix sub( C ) are overwritten by the
* local entries of the m by n updated submatrix.
*
* IC (global input) INTEGER
* On entry, IC specifies C's global row index, which points to
* the beginning of the submatrix sub( C ).
*
* JC (global input) INTEGER
* On entry, JC specifies C's global column index, which points
* to the beginning of the submatrix sub( C ).
*
* DESCC (global and local input) INTEGER array
* On entry, DESCC is an integer array of dimension DLEN_. This
* is the array descriptor for the matrix C.
*
* -- Written on April 1, 1998 by
* Antoine Petitet, University of Tennessee, Knoxville 37996, USA.
*
* ---------------------------------------------------------------------
*/
/*
* .. Local Scalars ..
*/
char DirA, DirC, ctop, rtop;
int Ai, Aj, Ci, Cj, TrA, ctxt, info, mycol, myrow, npcol, nprow,
notran;
/*
* .. Local Arrays ..
*/
int Ad[DLEN_], Cd[DLEN_];
/* ..
* .. Executable Statements ..
*
*/
notran = ( ( TrA = Mupcase( F2C_CHAR( TRANS )[0] ) ) == CNOTRAN );
PB_CargFtoC( *IA, *JA, DESCA, &Ai, &Aj, Ad );
PB_CargFtoC( *IC, *JC, DESCC, &Ci, &Cj, Cd );
#ifndef NO_ARGCHK
/*
* Test the input parameters
*/
Cblacs_gridinfo( ( ctxt = Ad[CTXT_] ), &nprow, &npcol, &myrow, &mycol );
if( !( info = ( ( nprow == -1 ) ? -( 801 + CTXT_ ) : 0 ) ) )
{
if( ( !notran ) && ( TrA != CTRAN ) && ( TrA != CCOTRAN ) )
{
PB_Cwarn( ctxt, __LINE__, "PSGEADD", "Illegal TRANS = %c\n", TrA );
info = -1;
}
if( notran )
PB_Cchkmat( ctxt, "PSGEADD", "A", *M, 2, *N, 3, Ai, Aj, Ad, 8,
&info );
else
PB_Cchkmat( ctxt, "PSGEADD", "A", *N, 3, *M, 2, Ai, Aj, Ad, 8,
&info );
PB_Cchkmat( ctxt, "PSGEADD", "C", *M, 2, *N, 3, Ci, Cj, Cd, 13, &info );
}
if( info ) { PB_Cabort( ctxt, "PSGEADD", info ); return; }
#endif
/*
* Quick return if possible
*/
if( ( *M == 0 ) || ( *N == 0 ) ||
( ( ALPHA[REAL_PART] == ZERO ) && ( BETA[REAL_PART] == ONE ) ) )
return;
/*
* And when alpha is zero
*/
if( ALPHA[REAL_PART] == ZERO )
{
if( BETA[REAL_PART] == ZERO )
{
PB_Cplapad( PB_Cstypeset(), ALL, NOCONJG, *M, *N, ((char *)BETA),
((char *)BETA), ((char *) C), Ci, Cj, Cd );
}
else
{
PB_Cplascal( PB_Cstypeset(), ALL, NOCONJG, *M, *N, ((char *)BETA),
((char * )C), Ci, Cj, Cd );
}
return;
}
/*
* Start the operations
*/
/*
* This operation mainly involves point-to-point send and receive communication.
* There is therefore no particular BLACS topology to recommend. Still, one can
* choose the main loop direction in which the operands will be added. This
* selection is based on the current setting for the BLACS broadcast operations.
*/
if( notran )
{
rtop = *PB_Ctop( &ctxt, BCAST, ROW, TOP_GET );
ctop = *PB_Ctop( &ctxt, BCAST, COLUMN, TOP_GET );
if( *M <= *N )
{
DirA = ( rtop == CTOP_DRING ? CBACKWARD : CFORWARD );
DirC = ( ctop == CTOP_DRING ? CBACKWARD : CFORWARD );
}
else
{
DirA = ( ctop == CTOP_DRING ? CBACKWARD : CFORWARD );
DirC = ( rtop == CTOP_DRING ? CBACKWARD : CFORWARD );
}
PB_Cpgeadd( PB_Cstypeset(), &DirA, &DirC, NOCONJG, *M, *N,
((char *) ALPHA), ((char *) A), Ai, Aj, Ad,
((char *) BETA), ((char *) C), Ci, Cj, Cd );
}
else
{
PB_Cptran( PB_Cstypeset(), NOCONJG, *M, *N, ((char *) ALPHA),
((char *) A), Ai, Aj, Ad, ((char *) BETA), ((char *) C),
Ci, Cj, Cd );
}
/*
* End of PSGEADD
*/
}
