1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
SUBROUTINE PCLATRAN( N, NB, A, IA, JA, DESCA, WORK )
*
* -- ScaLAPACK auxiliary routine (version 1.7) --
* University of Tennessee, Knoxville, Oak Ridge National Laboratory,
* and University of California, Berkeley.
* October 15, 1999
*
* .. Scalar Arguments ..
INTEGER IA, JA, N, NB
* ..
* .. Array Arguments ..
INTEGER DESCA( * )
COMPLEX A( * ), WORK( * )
* ..
*
* Purpose
*
* =======
*
* PCLATRAN transpose a lower triangular matrix on to the upper
* triangular portion of the same matrix.
*
* This is an auxiliary routine called by PCHETRD.
*
* Notes
* =====
*
* IA must equal 1
* JA must equal 1
* DESCA( MB_ ) must equal 1
* DESCA( NB_ ) must equal 1
* DESCA( RSRC_ ) must equal 1
* DESCA( CSRC_ ) must equal 1
*
*
* Arguments
* =========
*
* N (global input) INTEGER
* The size of the matrix to be transposed.
*
* NB (global input) INTEGER
* The number of rows and columns to be transposed with each
* message sent. NB has no impact on the result, it is striclty
* a performance tuning parameter.
*
* A (local input/local output) COMPLEX*16 pointer into the
* local memory to an array of dimension (LLD_A,LOCc(JA+N-1)).
* On entry, this array contains the local pieces of the
* Hermitian distributed matrix sub( A ). On entry, the
* leading N-by-N upper triangular part of sub( A ) contains
* the upper triangular part of the matrix. On exit, the
* leading N-by-N lower triangular part of sub( A ) contains the
* lower triangular part of the matrix, and its strictly upper
* triangular part is undefined (and may have been modified).
*
* IA (global input) INTEGER
* A's global row index, which points to the beginning of the
* submatrix which is to be operated on.
* Must be equal to 1.
*
* JA (global input) INTEGER
* A's global column index, which points to the beginning of
* the submatrix which is to be operated on.
* Must be equal to 1.
*
* DESCA (global and local input) INTEGER array of dimension DLEN_.
* The array descriptor for the distributed matrix A.
* DESCA( MB_ ) must equal 1
* DESCA( NB_ ) must equal 1
* DESCA( ICTXT_ ) must point to a square process grid
* i.e. one where NPROW is equal to NPCOL
*
* WORK (local workspace) COMPLEX*16 array, dimension ( LWORK )
*
* Where:
* LWORK >= NB * NUMROC( N, 1, 0, 0, NPROW )
*
* =====================================================================
*
* .. Parameters ..
INTEGER BLOCK_CYCLIC_2D, DLEN_, DTYPE_, CTXT_, M_, N_,
$ MB_, NB_, RSRC_, CSRC_, LLD_
PARAMETER ( BLOCK_CYCLIC_2D = 1, DLEN_ = 9, DTYPE_ = 1,
$ CTXT_ = 2, M_ = 3, N_ = 4, MB_ = 5, NB_ = 6,
$ RSRC_ = 7, CSRC_ = 8, LLD_ = 9 )
* ..
* .. Local Scalars ..
INTEGER I, ICTXT, IRECV, ISEND, J, JJ, JRECV, JSEND,
$ LDA, MAXIRECV, MAXISEND, MAXJRECV, MAXJSEND,
$ MINIRECV, MINISEND, MINJRECV, MINJSEND, MYCOL,
$ MYROW, NP, NPCOL, NPROW, NQ, RECVNB, SENDNB,
$ STARTCOL, STARTROW
* ..
* .. External Subroutines ..
EXTERNAL BLACS_GRIDINFO, CTRRV2D, CTRSD2D
* ..
* .. External Functions ..
INTEGER NUMROC
EXTERNAL NUMROC
* ..
* .. Intrinsic Functions ..
INTRINSIC CONJG, MAX, MIN
* ..
* .. Executable Statements ..
* This is just to keep ftnchek and toolpack/1 happy
IF( BLOCK_CYCLIC_2D*CSRC_*CTXT_*DLEN_*DTYPE_*LLD_*MB_*M_*NB_*N_*
$ RSRC_.LT.0 )RETURN
*
* Further details
*
* Because the processor grid is square each process needs only send
* data to its transpose process. (Likewsie it need only receive
* data from its transpose process.) Because the data decomposition
* is cyclic, the local portion of the array is triangular.
*
* This routine requires that the data be buffered (i.e. copied)
* on the sending process (because of the triangular shape) and
* unbuffered on the receiving process. Hence, two local memory to
* memory copies are performed within the communications routines
* followed by a memory to memory copy outside of the communications
* routines. It would be nice to avoid having back to back memory
* to memory copies (as we do presently on the receiving processor).
* This could be done by packaging the data ourselves in the sender
* and then unpacking it directly into the matrix. However, this
* code seems cleaner and so since this routine is not a significant
* performance bottleneck we have left it this way.
*
*
*
*
* Quick return if possible
*
IF( N.LE.0 )
$ RETURN
*
ICTXT = DESCA( CTXT_ )
LDA = DESCA( LLD_ )
CALL BLACS_GRIDINFO( ICTXT, NPROW, NPCOL, MYROW, MYCOL )
*
*
NP = NUMROC( N, 1, MYROW, 0, NPROW )
NQ = NUMROC( N, 1, MYCOL, 0, NPCOL )
*
*
IF( MYROW.EQ.MYCOL ) THEN
*
DO 20 J = 1, NP
DO 10 I = J + 1, NQ
A( J+( I-1 )*LDA ) = CONJG( A( I+( J-1 )*LDA ) )
10 CONTINUE
20 CONTINUE
*
ELSE
IF( MYROW.GT.MYCOL ) THEN
STARTROW = 1
STARTCOL = 2
ELSE
IF( MYROW.EQ.MYCOL ) THEN
STARTROW = 2
STARTCOL = 2
ELSE
STARTROW = 2
STARTCOL = 1
END IF
END IF
*
DO 50 JJ = 1, MAX( NP, NQ ), NB
MINJSEND = STARTCOL + JJ - 1
MINJRECV = STARTROW + JJ - 1
MAXJSEND = MIN( MINJSEND+NB-1, NQ )
MAXJRECV = MIN( MINJRECV+NB-1, NP )
*
SENDNB = MAXJSEND - MINJSEND + 1
RECVNB = MAXJRECV - MINJRECV + 1
*
MINISEND = 1
MINIRECV = 1
MAXISEND = MIN( NP, JJ+SENDNB-1 )
MAXIRECV = MIN( NQ, JJ+RECVNB-1 )
*
ISEND = MAXISEND - MINISEND + 1
IRECV = MAXIRECV - MINIRECV + 1
JSEND = MAXJSEND - MINJSEND + 1
JRECV = MAXJRECV - MINJRECV + 1
*
*
*
DO 40 J = MINJRECV, MAXJRECV
DO 30 I = MINIRECV, MAXIRECV + J - MAXJRECV
WORK( I+( J-MINJRECV )*IRECV )
$ = CONJG( A( J+( I-1 )*LDA ) )
30 CONTINUE
40 CONTINUE
*
IF( IRECV.GT.0 .AND. JRECV.GT.0 )
$ CALL CTRSD2D( ICTXT, 'U', 'N', IRECV, JRECV, WORK, IRECV,
$ MYCOL, MYROW )
*
IF( ISEND.GT.0 .AND. JSEND.GT.0 )
$ CALL CTRRV2D( ICTXT, 'U', 'N', ISEND, JSEND,
$ A( MINISEND+( MINJSEND-1 )*LDA ), LDA,
$ MYCOL, MYROW )
*
*
50 CONTINUE
*
END IF
*
RETURN
*
* End of PCLATRD
*
END
|
