ScaLAPACK 2.1  2.1
ScaLAPACK: Scalable Linear Algebra PACKage
pstran_.c
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1 /* ---------------------------------------------------------------------
2 *
3 * -- PBLAS routine (version 2.0) --
4 * University of Tennessee, Knoxville, Oak Ridge National Laboratory,
5 * and University of California, Berkeley.
6 * April 1, 1998
7 *
8 * ---------------------------------------------------------------------
9 */
10 /*
11 * Include files
12 */
13 #include "pblas.h"
14 #include "PBpblas.h"
15 #include "PBtools.h"
16 #include "PBblacs.h"
17 #include "PBblas.h"
18 
19 #ifdef __STDC__
20 void pstran_( int * M, int * N,
21  float * ALPHA,
22  float * A, int * IA, int * JA, int * DESCA,
23  float * BETA,
24  float * C, int * IC, int * JC, int * DESCC )
25 #else
26 void pstran_( M, N, ALPHA, A, IA, JA, DESCA, BETA, C, IC, JC, DESCC )
27 /*
28 * .. Scalar Arguments ..
29 */
30  int * IA, * IC, * JA, * JC, * M, * N;
31  float * ALPHA, * BETA;
32 /*
33 * .. Array Arguments ..
34 */
35  int * DESCA, * DESCC;
36  float * A, * C;
37 #endif
38 {
39 /*
40 * Purpose
41 * =======
42 *
43 * PSTRAN transposes a matrix
44 *
45 * sub( C ) := beta*sub( C ) + alpha*op( sub( A ) )
46 *
47 * where
48 *
49 * sub( C ) denotes C(IC:IC+M-1,JC:JC+N-1),
50 *
51 * sub( A ) denotes A(IA:IA+N-1,JA:JA+M-1), and, op( X ) = X'.
52 *
53 * Thus, op( sub( A ) ) denotes A(IA:IA+N-1,JA:JA+M-1)'.
54 *
55 * Beta is a scalar, sub( C ) is an m by n submatrix, and sub( A ) is an
56 * n by m submatrix.
57 *
58 * Notes
59 * =====
60 *
61 * A description vector is associated with each 2D block-cyclicly dis-
62 * tributed matrix. This vector stores the information required to
63 * establish the mapping between a matrix entry and its corresponding
64 * process and memory location.
65 *
66 * In the following comments, the character _ should be read as
67 * "of the distributed matrix". Let A be a generic term for any 2D
68 * block cyclicly distributed matrix. Its description vector is DESC_A:
69 *
70 * NOTATION STORED IN EXPLANATION
71 * ---------------- --------------- ------------------------------------
72 * DTYPE_A (global) DESCA[ DTYPE_ ] The descriptor type.
73 * CTXT_A (global) DESCA[ CTXT_ ] The BLACS context handle, indicating
74 * the NPROW x NPCOL BLACS process grid
75 * A is distributed over. The context
76 * itself is global, but the handle
77 * (the integer value) may vary.
78 * M_A (global) DESCA[ M_ ] The number of rows in the distribu-
79 * ted matrix A, M_A >= 0.
80 * N_A (global) DESCA[ N_ ] The number of columns in the distri-
81 * buted matrix A, N_A >= 0.
82 * IMB_A (global) DESCA[ IMB_ ] The number of rows of the upper left
83 * block of the matrix A, IMB_A > 0.
84 * INB_A (global) DESCA[ INB_ ] The number of columns of the upper
85 * left block of the matrix A,
86 * INB_A > 0.
87 * MB_A (global) DESCA[ MB_ ] The blocking factor used to distri-
88 * bute the last M_A-IMB_A rows of A,
89 * MB_A > 0.
90 * NB_A (global) DESCA[ NB_ ] The blocking factor used to distri-
91 * bute the last N_A-INB_A columns of
92 * A, NB_A > 0.
93 * RSRC_A (global) DESCA[ RSRC_ ] The process row over which the first
94 * row of the matrix A is distributed,
95 * NPROW > RSRC_A >= 0.
96 * CSRC_A (global) DESCA[ CSRC_ ] The process column over which the
97 * first column of A is distributed.
98 * NPCOL > CSRC_A >= 0.
99 * LLD_A (local) DESCA[ LLD_ ] The leading dimension of the local
100 * array storing the local blocks of
101 * the distributed matrix A,
102 * IF( Lc( 1, N_A ) > 0 )
103 * LLD_A >= MAX( 1, Lr( 1, M_A ) )
104 * ELSE
105 * LLD_A >= 1.
106 *
107 * Let K be the number of rows of a matrix A starting at the global in-
108 * dex IA,i.e, A( IA:IA+K-1, : ). Lr( IA, K ) denotes the number of rows
109 * that the process of row coordinate MYROW ( 0 <= MYROW < NPROW ) would
110 * receive if these K rows were distributed over NPROW processes. If K
111 * is the number of columns of a matrix A starting at the global index
112 * JA, i.e, A( :, JA:JA+K-1, : ), Lc( JA, K ) denotes the number of co-
113 * lumns that the process MYCOL ( 0 <= MYCOL < NPCOL ) would receive if
114 * these K columns were distributed over NPCOL processes.
115 *
116 * The values of Lr() and Lc() may be determined via a call to the func-
117 * tion PB_Cnumroc:
118 * Lr( IA, K ) = PB_Cnumroc( K, IA, IMB_A, MB_A, MYROW, RSRC_A, NPROW )
119 * Lc( JA, K ) = PB_Cnumroc( K, JA, INB_A, NB_A, MYCOL, CSRC_A, NPCOL )
120 *
121 * Arguments
122 * =========
123 *
124 * M (global input) INTEGER
125 * On entry, M specifies the number of rows of the submatrix
126 * sub( C ) and the number of columns of the submatrix sub( A ).
127 * M must be at least zero.
128 *
129 * N (global input) INTEGER
130 * On entry, N specifies the number of columns of the submatrix
131 * sub( C ) and the number of rows of the submatrix sub( A ). N
132 * must be at least zero.
133 *
134 * ALPHA (global input) REAL
135 * On entry, ALPHA specifies the scalar alpha. When ALPHA is
136 * supplied as zero then the local entries of the array A
137 * corresponding to the entries of the submatrix sub( A ) need
138 * not be set on input.
139 *
140 * A (local input) REAL array
141 * On entry, A is an array of dimension (LLD_A, Ka), where Ka is
142 * at least Lc( 1, JA+M-1 ). Before entry, this array contains
143 * the local entries of the matrix A.
144 *
145 * IA (global input) INTEGER
146 * On entry, IA specifies A's global row index, which points to
147 * the beginning of the submatrix sub( A ).
148 *
149 * JA (global input) INTEGER
150 * On entry, JA specifies A's global column index, which points
151 * to the beginning of the submatrix sub( A ).
152 *
153 * DESCA (global and local input) INTEGER array
154 * On entry, DESCA is an integer array of dimension DLEN_. This
155 * is the array descriptor for the matrix A.
156 *
157 * BETA (global input) REAL
158 * On entry, BETA specifies the scalar beta. When BETA is
159 * supplied as zero then the local entries of the array C
160 * corresponding to the entries of the submatrix sub( C ) need
161 * not be set on input.
162 *
163 * C (local input/local output) REAL array
164 * On entry, C is an array of dimension (LLD_C, Kc), where Kc is
165 * at least Lc( 1, JC+N-1 ). Before entry, this array contains
166 * the local entries of the matrix C.
167 * On exit, the entries of this array corresponding to the local
168 * entries of the submatrix sub( C ) are overwritten by the
169 * local entries of the m by n updated submatrix.
170 *
171 * IC (global input) INTEGER
172 * On entry, IC specifies C's global row index, which points to
173 * the beginning of the submatrix sub( C ).
174 *
175 * JC (global input) INTEGER
176 * On entry, JC specifies C's global column index, which points
177 * to the beginning of the submatrix sub( C ).
178 *
179 * DESCC (global and local input) INTEGER array
180 * On entry, DESCC is an integer array of dimension DLEN_. This
181 * is the array descriptor for the matrix C.
182 *
183 * -- Written on April 1, 1998 by
184 * Antoine Petitet, University of Tennessee, Knoxville 37996, USA.
185 *
186 * ---------------------------------------------------------------------
187 */
188 /*
189 * .. Local Scalars ..
190 */
191  int Ai, Aj, Ci, Cj, ctxt, info, mycol, myrow, npcol, nprow;
192 /*
193 * .. Local Arrays ..
194 */
195  int Ad[DLEN_], Cd[DLEN_];
196 /* ..
197 * .. Executable Statements ..
198 *
199 */
200  PB_CargFtoC( *IA, *JA, DESCA, &Ai, &Aj, Ad );
201  PB_CargFtoC( *IC, *JC, DESCC, &Ci, &Cj, Cd );
202 #ifndef NO_ARGCHK
203 /*
204 * Test the input parameters
205 */
206  Cblacs_gridinfo( ( ctxt = Ad[CTXT_] ), &nprow, &npcol, &myrow, &mycol );
207  if( !( info = ( ( nprow == -1 ) ? -( 701 + CTXT_ ) : 0 ) ) )
208  {
209  PB_Cchkmat( ctxt, "PSTRAN", "A", *N, 2, *M, 1, Ai, Aj, Ad, 7, &info );
210  PB_Cchkmat( ctxt, "PSTRAN", "C", *M, 1, *N, 2, Ci, Cj, Cd, 12, &info );
211  }
212  if( info ) { PB_Cabort( ctxt, "PSTRAN", info ); return; }
213 #endif
214 /*
215 * Quick return if possible
216 */
217  if( ( *M == 0 ) || ( *N == 0 ) ||
218  ( ( ALPHA[REAL_PART] == ZERO ) && ( BETA[REAL_PART] == ONE ) ) )
219  return;
220 /*
221 * And when alpha is zero
222 */
223  if( ALPHA[REAL_PART] == ZERO )
224  {
225  if( BETA[REAL_PART] == ZERO )
226  {
227  PB_Cplapad( PB_Cstypeset(), ALL, NOCONJG, *M, *N, ((char *)BETA),
228  ((char *)BETA), ((char *) C), Ci, Cj, Cd );
229  }
230  else
231  {
232  PB_Cplascal( PB_Cstypeset(), ALL, NOCONJG, *M, *N, ((char *)BETA),
233  ((char * )C), Ci, Cj, Cd );
234  }
235  return;
236  }
237 /*
238 * Start the operations
239 */
240  PB_Cptran( PB_Cstypeset(), NOCONJG, *M, *N, ((char *) ALPHA),
241  ((char *) A), Ai, Aj, Ad, ((char *) BETA), ((char *) C),
242  Ci, Cj, Cd );
243 /*
244 * End of PSTRAN
245 */
246 }
PBblacs.h
PBtools.h
PBblas.h
NOCONJG
#define NOCONJG
Definition: PBblas.h:45
REAL_PART
#define REAL_PART
Definition: pblas.h:135
PBpblas.h
DLEN_
#define DLEN_
Definition: PBtools.h:48
pstran_
void pstran_(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: pstran_.c:26
ZERO
#define ZERO
Definition: PBtools.h:66
PB_Cplascal
void PB_Cplascal()
PB_Cabort
void PB_Cabort()
PB_Cplapad
void PB_Cplapad()
ONE
#define ONE
Definition: PBtools.h:64
PB_CargFtoC
void PB_CargFtoC()
PB_Cchkmat
void PB_Cchkmat()
PB_Cstypeset
PBTYP_T * PB_Cstypeset()
Definition: PB_Cstypeset.c:19
ALL
#define ALL
Definition: PBblas.h:50
Cblacs_gridinfo
void Cblacs_gridinfo()
pblas.h
CTXT_
#define CTXT_
Definition: PBtools.h:38
PB_Cptran
void PB_Cptran()