/* --------------------------------------------------------------------- * * -- PBLAS auxiliary routine (version 2.0) -- * University of Tennessee, Knoxville, Oak Ridge National Laboratory, * and University of California, Berkeley. * April 1, 1998 * * --------------------------------------------------------------------- */ /* * Include files */ #include "../pblas.h" #include "../PBpblas.h" #include "../PBtools.h" #include "../PBblacs.h" #include "../PBblas.h" #ifdef __STDC__ void PB_Cplacnjg( PBTYP_T * TYPE, int M, int N, char * ALPHA, char * A, int IA, int JA, int * DESCA ) #else void PB_Cplacnjg( TYPE, M, N, ALPHA, A, IA, JA, DESCA ) /* * .. Scalar Arguments .. */ int IA, JA, M, N; char * ALPHA; PBTYP_T * TYPE; /* * .. Array Arguments .. */ int * DESCA; char * A; #endif { /* * Purpose * ======= * * PB_Cplacnjg conjugates and scales by alpha and an m by n submatrix * sub( A ) denoting A(IA:IA+M-1,JA:JA+N-1). * * 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 * ========= * * TYPE (local input) pointer to a PBTYP_T structure * On entry, TYPE is a pointer to a structure of type PBTYP_T, * that contains type information (See pblas.h). * * M (global input) INTEGER * On entry, M specifies the number of rows 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( A ). N must be at least zero. * * ALPHA (global input) pointer to CHAR * On entry, ALPHA specifies the scalar alpha, i.e., the cons- * tant with which the matrix elements are to be scaled. * * A (local input/local output) pointer to CHAR * On entry, A is an array of dimension (LLD_A, Ka), where Ka is * at least Lc( 1, JA+N-1 ). Before entry, this array contains * the local entries of the matrix A to be scaled. On exit, the * local entries of this array corresponding to the to the en- * tries of the submatrix sub( A ) are overwritten by the local * entries of the m by n conjugated and scaled submatrix. * * 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. * * -- Written on April 1, 1998 by * Antoine Petitet, University of Tennessee, Knoxville 37996, USA. * * --------------------------------------------------------------------- */ /* * .. Local Scalars .. */ int Acol, Arow, Aii, Aimb1, Ainb1, Ajj, Ald, Amb, Amp, Anb, Anq, izero=0, mycol, myrow, npcol, nprow; /* * .. Local Arrays .. */ int Ad0[DLEN_]; /* .. * .. Executable Statements .. * */ /* * Quick return if possible */ if( ( M <= 0 ) || ( N <= 0 ) ) return; /* * Retrieve process grid information */ Cblacs_gridinfo( DESCA[CTXT_], &nprow, &npcol, &myrow, &mycol ); /* * Compute descriptor Ad0 for sub( A ) */ PB_Cdescribe( M, N, IA, JA, DESCA, nprow, npcol, myrow, mycol, &Aii, &Ajj, &Ald, &Aimb1, &Ainb1, &Amb, &Anb, &Arow, &Acol, Ad0 ); /* * Quick return if I don't own any of sub( A ). */ Amp = PB_Cnumroc( M, 0, Aimb1, Amb, myrow, Arow, nprow ); Anq = PB_Cnumroc( N, 0, Ainb1, Anb, mycol, Acol, npcol ); if( ( Amp <= 0 ) || ( Anq <= 0 ) ) return; /* * Conjugate and scale local data */ TYPE->Ftzcnjg( C2F_CHAR( ALL ), &Amp, &Anq, &izero, ALPHA, Mptr( A, Aii, Ajj, Ald, TYPE->size ), &Ald ); /* * End of PB_Cplacnjg */ }