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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 | pctradd_ (F_CHAR_T UPLO, 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 pctradd_ | ( | F_CHAR_T | UPLO, |
| 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 pctradd_.c.
{
/*
* Purpose
* =======
*
* PCTRADD adds a trapezoidal 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' or op( X ) = conjg( 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',
* conjg(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
* upper or lower trapezoidal 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
* =========
*
* UPLO (global input) CHARACTER*1
* On entry, UPLO specifies whether the local pieces of the
* array C containing the upper or lower triangular part of the
* triangular submatrix sub( C ) is to be referenced as follows:
*
* UPLO = 'U' or 'u' Only the local pieces corresponding to
* the upper triangular part of the
* triangular submatrix sub( C ) is to be
* referenced,
*
* UPLO = 'L' or 'l' Only the local pieces corresponding to
* the lower triangular part of the
* triangular submatrix sub( C ) is to be
* referenced.
*
* 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 ) ) = conjg( 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) COMPLEX
* 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) COMPLEX array
* On entry, A is an array of dimension (LLD_A, Ka), where Ka is
* at least Lc( 1, JA+N-1 ) when TRANS = 'N' or 'n' and is at
* least Lc( 1, JA+M-1 ) otherwise. Before entry, this array
* contains the local entries of the matrix A.
* Before entry with UPLO = 'U' or 'u' and TRANS = 'N' or 'n' or
* UPLO = 'L' or 'l' and TRANS = 'T', 'C', 't' or 'c', this ar-
* ray contains the local entries corresponding to the entries
* of the upper triangular submatrix sub( A ), and the local en-
* tries corresponding to the entries of the strictly lower tri-
* angular part of the submatrix sub( A ) are not referenced.
* Before entry with UPLO = 'L' or 'l' and TRANS = 'N' or 'n' or
* UPLO = 'U' or 'u' and TRANS = 'T', 'C', 't' or 'c', this ar-
* ray contains the local entries corresponding to the entries
* of the lower triangular submatrix sub( A ), and the local en-
* tries corresponding to the entries of the strictly upper tri-
* angular part of the submatrix sub( A ) are not referenced.
*
* 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) COMPLEX
* 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) COMPLEX 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.
* Before entry with UPLO = 'U' or 'u', this array contains
* the local entries corresponding to the upper triangular part
* of the triangular submatrix sub( C ), and the local entries
* corresponding to the strictly lower triangular of sub( C )
* are not referenced. On exit, the upper triangular part of
* sub( C ) is overwritten by the upper triangular part of the
* updated submatrix.
* Before entry with UPLO = 'L' or 'l', this array contains
* the local entries corresponding to the lower triangular part
* of the triangular submatrix sub( C ), and the local entries
* corresponding to the strictly upper triangular of sub( C )
* are not referenced. On exit, the lower triangular part of
* sub( C ) is overwritten by the lower triangular part of the
* 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 DirAC, TranOp, UploC, ctop, rtop;
int Ai, Aj, Ci, Cj, ctxt, info, mycol, myrow, notran, npcol,
nprow, upper;
/*
* .. Local Arrays ..
*/
int Ad[DLEN_], Cd[DLEN_];
/* ..
* .. Executable Statements ..
*
*/
upper = ( ( UploC = Mupcase( F2C_CHAR( UPLO )[0] ) ) == CUPPER );
notran = ( ( TranOp = 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 ) ? -( 901 + CTXT_ ) : 0 ) ) )
{
if( ( !upper ) && ( UploC != CLOWER ) )
{
PB_Cwarn( ctxt, __LINE__, "PCTRADD", "Illegal UPLO = %c\n", UploC );
info = -1;
}
else if( ( !notran ) && ( TranOp != CTRAN ) && ( TranOp != CCOTRAN ) )
{
PB_Cwarn( ctxt, __LINE__, "PCTRADD", "Illegal TRANS = %c\n", TranOp );
info = -2;
}
if( notran )
PB_Cchkmat( ctxt, "PCTRADD", "A", *M, 3, *N, 4, Ai, Aj, Ad, 9,
&info );
else
PB_Cchkmat( ctxt, "PCTRADD", "A", *N, 4, *M, 3, Ai, Aj, Ad, 9,
&info );
PB_Cchkmat( ctxt, "PCTRADD", "C", *M, 3, *N, 4, Ci, Cj, Cd, 14,
&info );
}
if( info ) { PB_Cabort( ctxt, "PCTRADD", info ); return; }
#endif
/*
* Quick return if possible
*/
if( ( *M == 0 ) || ( *N == 0 ) ||
( ( ALPHA[REAL_PART] == ZERO && ALPHA[IMAG_PART] == ZERO ) &&
( BETA [REAL_PART] == ONE && BETA [IMAG_PART] == ZERO ) ) )
return;
/*
* And when alpha is zero
*/
if( ( ALPHA[REAL_PART] == ZERO ) && ( ALPHA[IMAG_PART] == ZERO ) )
{
if( ( BETA[REAL_PART] == ZERO ) && ( BETA[IMAG_PART] == ZERO ) )
{
PB_Cplapad( PB_Cctypeset(), &UploC, NOCONJG, *M, *N,
((char *)BETA), ((char *)BETA), ((char *) C), Ci, Cj, Cd );
}
else
{
PB_Cplascal( PB_Cctypeset(), &UploC, 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, but not
* transposed. This selection is based on the current setting for the BLACS
* broadcast operations.
*/
rtop = *PB_Ctop( &ctxt, BCAST, ROW, TOP_GET );
ctop = *PB_Ctop( &ctxt, BCAST, COLUMN, TOP_GET );
if( *M <= *N )
DirAC = ( rtop == CTOP_DRING ? CBACKWARD : CFORWARD );
else
DirAC = ( ctop == CTOP_DRING ? CBACKWARD : CFORWARD );
PB_Cptradd( PB_Cctypeset(), &DirAC, &UploC, ( notran ? NOTRAN :
( ( TranOp == CCOTRAN ) ? COTRAN : TRAN ) ), *M, *N,
((char *) ALPHA), ((char *) A), Ai, Aj, Ad, ((char *) BETA),
((char *) C), Ci, Cj, Cd );
/*
* End of PCTRADD
*/
}
