|
ScaLAPACK
2.0.2
ScaLAPACK: Scalable Linear Algebra PACKage
|
|
ScaLAPACK
2.0.2
ScaLAPACK: Scalable Linear Algebra PACKage
|
#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 | pcsyrk_ (F_CHAR_T UPLO, F_CHAR_T TRANS, int *N, int *K, float *ALPHA, float *A, int *IA, int *JA, int *DESCA, float *BETA, float *C, int *IC, int *JC, int *DESCC) |
| void pcsyrk_ | ( | F_CHAR_T | UPLO, |
| F_CHAR_T | TRANS, | ||
| int * | N, | ||
| int * | K, | ||
| 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 pcsyrk_.c.
{
/*
* Purpose
* =======
*
* PCSYRK performs one of the symmetric rank k operations
*
* sub( C ) := alpha*sub( A )*sub( A )' + beta*sub( C ),
*
* or
*
* sub( C ) := alpha*sub( A )'*sub( A ) + beta*sub( C ),
*
* where
*
* sub( C ) denotes C(IC:IC+N-1,JC:JC+N-1), and,
*
* sub( A ) denotes A(IA:IA+N-1,JA:JA+K-1) if TRANS = 'N',
* A(IA:IA+K-1,JA:JA+N-1) otherwise.
*
* Alpha and beta are scalars, sub( C ) is an n by n symmetric
* submatrix and sub( A ) is an n by k submatrix in the first case and a
* k by n submatrix in the second case.
*
* 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 symmetric submatrix sub( C ) are to be referenced as
* follows:
*
* UPLO = 'U' or 'u' Only the local pieces corresponding to
* the upper triangular part of the
* symmetric submatrix sub( C ) are to be
* referenced,
*
* UPLO = 'L' or 'l' Only the local pieces corresponding to
* the lower triangular part of the
* symmetric submatrix sub( C ) are to be
* referenced.
*
* TRANS (global input) CHARACTER*1
* On entry, TRANS specifies the operation to be performed as
* follows:
*
* TRANS = 'N' or 'n'
* sub( C ) := alpha*sub( A )*sub( A )' + beta*sub( C ),
*
* TRANS = 'T' or 't'
* sub( C ) := alpha*sub( A )'*sub( A ) + beta*sub( C ).
*
* N (global input) INTEGER
* On entry, N specifies the order of the submatrix sub( C ).
* N must be at least zero.
*
* K (global input) INTEGER
* On entry, with TRANS = 'N' or 'n', K specifies the number of
* columns of the submatrix sub( A ), and with TRANS = 'T' or
* 't', K specifies the number of rows of the submatrix
* sub( A ). K 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+K-1 ) when TRANS = 'N' or 'n', and is at
* least Lc( 1, JA+N-1 ) otherwise. Before entry, this array
* contains the local entries of the matrix A.
* Before entry with TRANS = 'N' or 'n', this array contains the
* local entries corresponding to the entries of the n by k sub-
* matrix sub( A ), otherwise the local entries corresponding to
* the entries of the k by n submatrix sub( 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) 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 symmetric 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 symmetric 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 DirA, OpC, OpR, TopC, TopR, TranOp, UploC, ctop, ctopsave,
rtop, rtopsave;
int Ai, Aj, ChooseAC, Ci, Cj, ForceTop, ctxt, info, mycol,
myrow, nb, notran, npcol, nprow, upper;
double Aest, ACest, tmp1, tmp2, tmp3, tmp4;
PBTYP_T * type;
/*
* .. 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__, "PCSYRK", "Illegal UPLO = %c\n", UploC );
info = -1;
}
else if( ( !notran ) && ( TranOp != CTRAN ) )
{
PB_Cwarn( ctxt, __LINE__, "PCSYRK", "Illegal TRANS = %c\n", TranOp );
info = -2;
}
if( notran )
PB_Cchkmat( ctxt, "PCSYRK", "A", *N, 3, *K, 4, Ai, Aj, Ad, 9,
&info );
else
PB_Cchkmat( ctxt, "PCSYRK", "A", *K, 4, *N, 3, Ai, Aj, Ad, 9,
&info );
PB_Cchkmat( ctxt, "PCSYRK", "C", *N, 3, *N, 3, Ci, Cj, Cd, 14,
&info );
}
if( info ) { PB_Cabort( ctxt, "PCSYRK", info ); return; }
#endif
/*
* Quick return if possible
*/
if( ( *N == 0 ) ||
( ( ( ( ALPHA[REAL_PART] == ZERO ) && ( ALPHA[IMAG_PART] == ZERO ) ) ||
( *K == 0 ) ) &&
( ( BETA[REAL_PART] == ONE ) && ( BETA[IMAG_PART] == ZERO ) ) ) )
return;
/*
* Get type structure
*/
type = PB_Cctypeset();
/*
* And when alpha or K is zero
*/
if( ( ( ALPHA[REAL_PART] == ZERO ) && ( ALPHA[IMAG_PART] == ZERO ) ) ||
( *K == 0 ) )
{
if( ( BETA[REAL_PART] == ZERO ) && ( BETA[IMAG_PART] == ZERO ) )
{
PB_Cplapad( type, &UploC, NOCONJG, *N, *N, type->zero, type->zero,
((char *) C), Ci, Cj, Cd );
}
else
{
PB_Cplascal( type, &UploC, NOCONJG, *N, *N, ((char *) BETA),
((char *) C), Ci, Cj, Cd );
}
return;
}
/*
* Start the operations
*/
#ifdef NO_ARGCHK
Cblacs_gridinfo( ( ctxt = Ad[CTXT_] ), &nprow, &npcol, &myrow, &mycol );
#endif
/*
* Algorithm selection is based on approximation of the communication volume
* for distributed and aligned operands.
*
* ACest: both operands sub( A ) and sub( C ) are communicated (K >> N)
* Aest : only sub( A ) is communicated (N >> K)
*/
if( notran )
{
tmp1 = DNROC( *N, Cd[MB_], nprow ); tmp3 = DNROC( *K, Ad[NB_], npcol );
ACest = (double)(*N) *
( ( ( ( Ad[RSRC_] == -1 ) || ( nprow == 1 ) ) ? ZERO : tmp3 ) +
( ( ( Ad[CSRC_] == -1 ) || ( npcol == 1 ) ) ? ZERO :
CBRATIO * tmp1 / TWO ) );
tmp1 = DNROC( *N, Cd[MB_], nprow ); tmp2 = DNROC( *N, Cd[NB_], npcol );
tmp4 = DNROC( *N, Ad[MB_], nprow );
Aest = (double)(*K) *
( ( ( ( Ad[CSRC_] == -1 ) || ( npcol == 1 ) ) ? ZERO : tmp1 ) +
( nprow == 1 ? ZERO : tmp2 ) + MAX( tmp2, tmp4 ) );
}
else
{
tmp2 = DNROC( *N, Cd[NB_], npcol ); tmp4 = DNROC( *K, Ad[MB_], nprow );
ACest = (double)(*N) *
( ( ( ( Ad[CSRC_] == -1 ) || ( npcol == 1 ) ) ? ZERO : tmp4 ) +
( ( ( Ad[RSRC_] == -1 ) || ( nprow == 1 ) ) ? ZERO :
CBRATIO * tmp2 / TWO ) );
tmp1 = DNROC( *N, Cd[MB_], nprow ); tmp2 = DNROC( *N, Cd[NB_], npcol );
tmp3 = DNROC( *N, Ad[NB_], npcol );
Aest = (double)(*K) *
( ( ( ( Ad[RSRC_] == -1 ) || ( nprow == 1 ) ) ? ZERO : tmp2 ) +
( npcol == 1 ? ZERO : tmp1 ) + MAX( tmp1, tmp3 ) );
}
/*
* Shift a little the cross-over point between both algorithms.
*/
ChooseAC = ( ( 1.3 * ACest ) <= Aest );
/*
* BLACS topologies are enforced iff N and K are strictly greater than the
* logical block size returned by pilaenv_. Otherwise, it is assumed that the
* routine calling this routine has already selected an adequate topology.
*/
nb = pilaenv_( &ctxt, C2F_CHAR( &type->type ) );
ForceTop = ( ( *N > nb ) && ( *K > nb ) );
if( ChooseAC )
{
if( notran )
{
OpC = CBCAST;
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, TOP_GET );
if( ForceTop )
{
OpR = CCOMBINE;
rtop = *PB_Ctop( &ctxt, &OpR, ROW, TOP_GET );
rtopsave = rtop;
ctopsave = ctop;
if( upper ) { TopR = CTOP_IRING; TopC = CTOP_DRING; }
else { TopR = CTOP_DRING; TopC = CTOP_IRING; }
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, &TopC );
rtop = *PB_Ctop( &ctxt, &OpR, ROW, &TopR );
/*
* Remove the next line when the BLACS combine operations support ring
* topologies
*/
rtop = *PB_Ctop( &ctxt, &OpR, ROW, TOP_DEFAULT );
}
DirA = ( ctop == CTOP_DRING ? CBACKWARD : CFORWARD );
}
else
{
OpR = CBCAST;
rtop = *PB_Ctop( &ctxt, &OpR, ROW, TOP_GET );
if( ForceTop )
{
OpC = CCOMBINE;
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, TOP_GET );
rtopsave = rtop;
ctopsave = ctop;
if( upper ) { TopR = CTOP_IRING; TopC = CTOP_DRING; }
else { TopR = CTOP_DRING; TopC = CTOP_IRING; }
rtop = *PB_Ctop( &ctxt, &OpR, ROW, &TopR );
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, &TopC );
/*
* Remove the next line when the BLACS combine operations support ring
* topologies
*/
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, TOP_DEFAULT );
}
DirA = ( rtop == CTOP_DRING ? CBACKWARD : CFORWARD );
}
PB_CpsyrkAC( type, &DirA, NOCONJG, &UploC, ( notran ? NOTRAN : TRAN ), *N,
*K, ((char *)ALPHA), ((char *)A), Ai, Aj, Ad, ((char *)BETA),
((char *)C), Ci, Cj, Cd );
}
else
{
if( notran )
{
OpR = CBCAST;
rtop = *PB_Ctop( &ctxt, &OpR, ROW, TOP_GET );
if( ForceTop )
{
OpC = CBCAST;
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, TOP_GET );
rtopsave = rtop;
ctopsave = ctop;
/*
* No clear winner for the ring topologies, so that if a ring topology is
* already selected, keep it.
*/
if( ( rtop != CTOP_DRING ) && ( rtop != CTOP_IRING ) &&
( rtop != CTOP_SRING ) )
rtop = *PB_Ctop( &ctxt, &OpR, ROW, TOP_SRING );
if( ( ctop != CTOP_DRING ) && ( ctop != CTOP_IRING ) &&
( ctop != CTOP_SRING ) )
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, TOP_SRING );
}
DirA = ( rtop == CTOP_DRING ? CBACKWARD : CFORWARD );
}
else
{
OpC = CBCAST;
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, TOP_GET );
if( ForceTop )
{
OpR = CBCAST;
rtop = *PB_Ctop( &ctxt, &OpR, ROW, TOP_GET );
rtopsave = rtop;
ctopsave = ctop;
/*
* No clear winner for the ring topologies, so that if a ring topology is
* already selected, keep it.
*/
if( ( rtop != CTOP_DRING ) && ( rtop != CTOP_IRING ) &&
( rtop != CTOP_SRING ) )
rtop = *PB_Ctop( &ctxt, &OpR, ROW, TOP_SRING );
if( ( ctop != CTOP_DRING ) && ( ctop != CTOP_IRING ) &&
( ctop != CTOP_SRING ) )
ctop = *PB_Ctop( &ctxt, &OpC, COLUMN, TOP_SRING );
}
DirA = ( ctop == CTOP_DRING ? CBACKWARD : CFORWARD );
}
PB_CpsyrkA( type, &DirA, NOCONJG, &UploC, ( notran ? NOTRAN : TRAN ), *N,
*K, ((char *)ALPHA), ((char *)A), Ai, Aj, Ad, ((char *)BETA),
((char *)C), Ci, Cj, Cd );
}
/*
* Restore the BLACS topologies when necessary.
*/
if( ForceTop )
{
rtopsave = *PB_Ctop( &ctxt, &OpR, ROW, &rtopsave );
ctopsave = *PB_Ctop( &ctxt, &OpC, COLUMN, &ctopsave );
}
/*
* End of PCSYRK
*/
}
