ScaLAPACK 2.1  2.1
ScaLAPACK: Scalable Linear Algebra PACKage
pzunmr3.f
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1  SUBROUTINE pzunmr3( SIDE, TRANS, M, N, K, L, A, IA, JA, DESCA,
2  $ TAU, C, IC, JC, DESCC, WORK, LWORK, INFO )
3 *
4 * -- ScaLAPACK routine (version 1.7) --
5 * University of Tennessee, Knoxville, Oak Ridge National Laboratory,
6 * and University of California, Berkeley.
7 * May 25, 2001
8 *
9 * .. Scalar Arguments ..
10  CHARACTER SIDE, TRANS
11  INTEGER IA, IC, INFO, JA, JC, K, L, LWORK, M, N
12 * ..
13 * .. Array Arguments ..
14  INTEGER DESCA( * ), DESCC( * )
15  COMPLEX*16 A( * ), C( * ), TAU( * ), WORK( * )
16 * ..
17 *
18 * Purpose
19 * =======
20 *
21 * PZUNMR3 overwrites the general complex M-by-N distributed matrix
22 * sub( C ) = C(IC:IC+M-1,JC:JC+N-1) with
23 *
24 * SIDE = 'L' SIDE = 'R'
25 * TRANS = 'N': Q * sub( C ) sub( C ) * Q
26 * TRANS = 'C': Q**H * sub( C ) sub( C ) * Q**H
27 *
28 * where Q is a complex unitary distributed matrix defined as the
29 * product of K elementary reflectors
30 *
31 * Q = H(1)' H(2)' . . . H(k)'
32 *
33 * as returned by PZTZRZF. Q is of order M if SIDE = 'L' and of order N
34 * if SIDE = 'R'.
35 *
36 * Notes
37 * =====
38 *
39 * Each global data object is described by an associated description
40 * vector. This vector stores the information required to establish
41 * the mapping between an object element and its corresponding process
42 * and memory location.
43 *
44 * Let A be a generic term for any 2D block cyclicly distributed array.
45 * Such a global array has an associated description vector DESCA.
46 * In the following comments, the character _ should be read as
47 * "of the global array".
48 *
49 * NOTATION STORED IN EXPLANATION
50 * --------------- -------------- --------------------------------------
51 * DTYPE_A(global) DESCA( DTYPE_ )The descriptor type. In this case,
52 * DTYPE_A = 1.
53 * CTXT_A (global) DESCA( CTXT_ ) The BLACS context handle, indicating
54 * the BLACS process grid A is distribu-
55 * ted over. The context itself is glo-
56 * bal, but the handle (the integer
57 * value) may vary.
58 * M_A (global) DESCA( M_ ) The number of rows in the global
59 * array A.
60 * N_A (global) DESCA( N_ ) The number of columns in the global
61 * array A.
62 * MB_A (global) DESCA( MB_ ) The blocking factor used to distribute
63 * the rows of the array.
64 * NB_A (global) DESCA( NB_ ) The blocking factor used to distribute
65 * the columns of the array.
66 * RSRC_A (global) DESCA( RSRC_ ) The process row over which the first
67 * row of the array A is distributed.
68 * CSRC_A (global) DESCA( CSRC_ ) The process column over which the
69 * first column of the array A is
70 * distributed.
71 * LLD_A (local) DESCA( LLD_ ) The leading dimension of the local
72 * array. LLD_A >= MAX(1,LOCr(M_A)).
73 *
74 * Let K be the number of rows or columns of a distributed matrix,
75 * and assume that its process grid has dimension p x q.
76 * LOCr( K ) denotes the number of elements of K that a process
77 * would receive if K were distributed over the p processes of its
78 * process column.
79 * Similarly, LOCc( K ) denotes the number of elements of K that a
80 * process would receive if K were distributed over the q processes of
81 * its process row.
82 * The values of LOCr() and LOCc() may be determined via a call to the
83 * ScaLAPACK tool function, NUMROC:
84 * LOCr( M ) = NUMROC( M, MB_A, MYROW, RSRC_A, NPROW ),
85 * LOCc( N ) = NUMROC( N, NB_A, MYCOL, CSRC_A, NPCOL ).
86 * An upper bound for these quantities may be computed by:
87 * LOCr( M ) <= ceil( ceil(M/MB_A)/NPROW )*MB_A
88 * LOCc( N ) <= ceil( ceil(N/NB_A)/NPCOL )*NB_A
89 *
90 * Arguments
91 * =========
92 *
93 * SIDE (global input) CHARACTER
94 * = 'L': apply Q or Q**H from the Left;
95 * = 'R': apply Q or Q**H from the Right.
96 *
97 * TRANS (global input) CHARACTER
98 * = 'N': No transpose, apply Q;
99 * = 'C': Conjugate transpose, apply Q**H.
100 *
101 * M (global input) INTEGER
102 * The number of rows to be operated on i.e the number of rows
103 * of the distributed submatrix sub( C ). M >= 0.
104 *
105 * N (global input) INTEGER
106 * The number of columns to be operated on i.e the number of
107 * columns of the distributed submatrix sub( C ). N >= 0.
108 *
109 * K (global input) INTEGER
110 * The number of elementary reflectors whose product defines the
111 * matrix Q. If SIDE = 'L', M >= K >= 0, if SIDE = 'R',
112 * N >= K >= 0.
113 *
114 * L (global input) INTEGER
115 * The columns of the distributed submatrix sub( A ) containing
116 * the meaningful part of the Householder reflectors.
117 * If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0.
118 *
119 * A (local input) COMPLEX*16 pointer into the local memory
120 * to an array of dimension (LLD_A,LOCc(JA+M-1)) if SIDE='L',
121 * and (LLD_A,LOCc(JA+N-1)) if SIDE='R', where
122 * LLD_A >= MAX(1,LOCr(IA+K-1)); On entry, the i-th row must
123 * contain the vector which defines the elementary reflector
124 * H(i), IA <= i <= IA+K-1, as returned by PZTZRZF in the
125 * K rows of its distributed matrix argument A(IA:IA+K-1,JA:*).
126 * A(IA:IA+K-1,JA:*) is modified by the routine but restored on
127 * exit.
128 *
129 * IA (global input) INTEGER
130 * The row index in the global array A indicating the first
131 * row of sub( A ).
132 *
133 * JA (global input) INTEGER
134 * The column index in the global array A indicating the
135 * first column of sub( A ).
136 *
137 * DESCA (global and local input) INTEGER array of dimension DLEN_.
138 * The array descriptor for the distributed matrix A.
139 *
140 * TAU (local input) COMPLEX*16, array, dimension LOCc(IA+K-1).
141 * This array contains the scalar factors TAU(i) of the
142 * elementary reflectors H(i) as returned by PZTZRZF.
143 * TAU is tied to the distributed matrix A.
144 *
145 * C (local input/local output) COMPLEX*16 pointer into the
146 * local memory to an array of dimension (LLD_C,LOCc(JC+N-1)).
147 * On entry, the local pieces of the distributed matrix sub(C).
148 * On exit, sub( C ) is overwritten by Q*sub( C ) or Q'*sub( C )
149 * or sub( C )*Q' or sub( C )*Q.
150 *
151 * IC (global input) INTEGER
152 * The row index in the global array C indicating the first
153 * row of sub( C ).
154 *
155 * JC (global input) INTEGER
156 * The column index in the global array C indicating the
157 * first column of sub( C ).
158 *
159 * DESCC (global and local input) INTEGER array of dimension DLEN_.
160 * The array descriptor for the distributed matrix C.
161 *
162 * WORK (local workspace/local output) COMPLEX*16 array,
163 * dimension (LWORK)
164 * On exit, WORK(1) returns the minimal and optimal LWORK.
165 *
166 * LWORK (local or global input) INTEGER
167 * The dimension of the array WORK.
168 * LWORK is local input and must be at least
169 * If SIDE = 'L', LWORK >= MpC0 + MAX( MAX( 1, NqC0 ), NUMROC(
170 * NUMROC( M+IROFFC,MB_A,0,0,NPROW ),MB_A,0,0,LCMP ) );
171 * if SIDE = 'R', LWORK >= NqC0 + MAX( 1, MpC0 );
172 *
173 * where LCMP = LCM / NPROW with LCM = ICLM( NPROW, NPCOL ),
174 *
175 * IROFFC = MOD( IC-1, MB_C ), ICOFFC = MOD( JC-1, NB_C ),
176 * ICROW = INDXG2P( IC, MB_C, MYROW, RSRC_C, NPROW ),
177 * ICCOL = INDXG2P( JC, NB_C, MYCOL, CSRC_C, NPCOL ),
178 * MpC0 = NUMROC( M+IROFFC, MB_C, MYROW, ICROW, NPROW ),
179 * NqC0 = NUMROC( N+ICOFFC, NB_C, MYCOL, ICCOL, NPCOL ),
180 *
181 * ILCM, INDXG2P and NUMROC are ScaLAPACK tool functions;
182 * MYROW, MYCOL, NPROW and NPCOL can be determined by calling
183 * the subroutine BLACS_GRIDINFO.
184 *
185 * If LWORK = -1, then LWORK is global input and a workspace
186 * query is assumed; the routine only calculates the minimum
187 * and optimal size for all work arrays. Each of these
188 * values is returned in the first entry of the corresponding
189 * work array, and no error message is issued by PXERBLA.
190 *
191 *
192 * INFO (local output) INTEGER
193 * = 0: successful exit
194 * < 0: If the i-th argument is an array and the j-entry had
195 * an illegal value, then INFO = -(i*100+j), if the i-th
196 * argument is a scalar and had an illegal value, then
197 * INFO = -i.
198 *
199 * Alignment requirements
200 * ======================
201 *
202 * The distributed submatrices A(IA:*, JA:*) and C(IC:IC+M-1,JC:JC+N-1)
203 * must verify some alignment properties, namely the following
204 * expressions should be true:
205 *
206 * If SIDE = 'L',
207 * ( NB_A.EQ.MB_C .AND. ICOFFA.EQ.IROFFC )
208 * If SIDE = 'R',
209 * ( NB_A.EQ.NB_C .AND. ICOFFA.EQ.ICOFFC .AND. IACOL.EQ.ICCOL )
210 *
211 * =====================================================================
212 *
213 * .. Parameters ..
214  INTEGER BLOCK_CYCLIC_2D, CSRC_, CTXT_, DLEN_, DTYPE_,
215  $ lld_, mb_, m_, nb_, n_, rsrc_
216  parameter( block_cyclic_2d = 1, dlen_ = 9, dtype_ = 1,
217  $ ctxt_ = 2, m_ = 3, n_ = 4, mb_ = 5, nb_ = 6,
218  $ rsrc_ = 7, csrc_ = 8, lld_ = 9 )
219 * ..
220 * .. Local Scalars ..
221  LOGICAL LEFT, LQUERY, NOTRAN
222  CHARACTER COLBTOP, ROWBTOP
223  INTEGER I, I1, I2, I3, IACOL, ICC, ICCOL, ICOFFA,
224  $ icoffc, icrow, ictxt, iroffc, jaa, jcc, lcm,
225  $ lcmp, lwmin, mi, mpc0, mycol, myrow, ni, npcol,
226  $ nprow, nq, nqc0
227 * ..
228 * .. External Subroutines ..
229  EXTERNAL blacs_abort, blacs_gridinfo, chk1mat,
230  $ pb_topget, pb_topset, pxerbla, pzlarz, pzlarzc
231 * ..
232 * .. External Functions ..
233  LOGICAL LSAME
234  INTEGER ILCM, INDXG2P, NUMROC
235  EXTERNAL ilcm, indxg2p, lsame, numroc
236 * ..
237 * .. Intrinsic Functions ..
238  INTRINSIC dble, dcmplx, max, mod
239 * ..
240 * .. Executable Statements ..
241 *
242 * Get grid parameters
243 *
244  ictxt = desca( ctxt_ )
245  CALL blacs_gridinfo( ictxt, nprow, npcol, myrow, mycol )
246 *
247 * Test the input parameters
248 *
249  info = 0
250  IF( nprow.EQ.-1 ) THEN
251  info = -(900+ctxt_)
252  ELSE
253  left = lsame( side, 'L' )
254  notran = lsame( trans, 'N' )
255 *
256 * NQ is the order of Q
257 *
258  IF( left ) THEN
259  nq = m
260  CALL chk1mat( k, 5, m, 3, ia, ja, desca, 10, info )
261  ELSE
262  nq = n
263  CALL chk1mat( k, 5, n, 4, ia, ja, desca, 10, info )
264  END IF
265  CALL chk1mat( m, 3, n, 4, ic, jc, descc, 15, info )
266  IF( info.EQ.0 ) THEN
267  icoffa = mod( ja-1, desca( nb_ ) )
268  iroffc = mod( ic-1, descc( mb_ ) )
269  icoffc = mod( jc-1, descc( nb_ ) )
270  iacol = indxg2p( ja, desca( nb_ ), mycol, desca( csrc_ ),
271  $ npcol )
272  icrow = indxg2p( ic, descc( mb_ ), myrow, descc( rsrc_ ),
273  $ nprow )
274  iccol = indxg2p( jc, descc( nb_ ), mycol, descc( csrc_ ),
275  $ npcol )
276  mpc0 = numroc( m+iroffc, descc( mb_ ), myrow, icrow, nprow )
277  nqc0 = numroc( n+icoffc, descc( nb_ ), mycol, iccol, npcol )
278 *
279  IF( left ) THEN
280  lcm = ilcm( nprow, npcol )
281  lcmp = lcm / nprow
282  lwmin = mpc0 + max( max( 1, nqc0 ), numroc( numroc(
283  $ m+iroffc, desca( mb_ ), 0, 0, nprow ),
284  $ desca( mb_ ), 0, 0, lcmp ) )
285  ELSE
286  lwmin = nqc0 + max( 1, mpc0 )
287  END IF
288 *
289  work( 1 ) = dcmplx( dble( lwmin ) )
290  lquery = ( lwork.EQ.-1 )
291  IF( .NOT.left .AND. .NOT.lsame( side, 'R' ) ) THEN
292  info = -1
293  ELSE IF( .NOT.notran .AND. .NOT.lsame( trans, 'C' ) ) THEN
294  info = -2
295  ELSE IF( k.LT.0 .OR. k.GT.nq ) THEN
296  info = -5
297  ELSE IF( l.LT.0 .OR. l.GT.nq ) THEN
298  info = -6
299  ELSE IF( left .AND. desca( nb_ ).NE.descc( mb_ ) ) THEN
300  info = -(1000+nb_)
301  ELSE IF( left .AND. icoffa.NE.iroffc ) THEN
302  info = -13
303  ELSE IF( .NOT.left .AND. icoffa.NE.icoffc ) THEN
304  info = -14
305  ELSE IF( .NOT.left .AND. iacol.NE.iccol ) THEN
306  info = -14
307  ELSE IF( .NOT.left .AND. desca( nb_ ).NE.descc( nb_ ) ) THEN
308  info = -(1500+nb_)
309  ELSE IF( ictxt.NE.descc( ctxt_ ) ) THEN
310  info = -(1500+ctxt_)
311  ELSE IF( lwork.LT.lwmin .AND. .NOT.lquery ) THEN
312  info = -17
313  END IF
314  END IF
315  END IF
316 *
317  IF( info.NE.0 ) THEN
318  CALL pxerbla( ictxt, 'PZUNMR3', -info )
319  CALL blacs_abort( ictxt, 1 )
320  RETURN
321  ELSE IF( lquery ) THEN
322  RETURN
323  END IF
324 *
325 * Quick return if possible
326 *
327  IF( m.EQ.0 .OR. n.EQ.0 .OR. k.EQ.0 )
328  $ RETURN
329 *
330  CALL pb_topget( ictxt, 'Broadcast', 'Rowwise', rowbtop )
331  CALL pb_topget( ictxt, 'Broadcast', 'Columnwise', colbtop )
332 *
333  IF( ( left .AND. .NOT.notran .OR. .NOT.left .AND. notran ) ) THEN
334  i1 = ia
335  i2 = ia + k - 1
336  i3 = 1
337  ELSE
338  i1 = ia + k - 1
339  i2 = ia
340  i3 = -1
341  END IF
342 *
343  IF( left ) THEN
344  ni = n
345  jcc = jc
346  jaa = ja + m - l
347  ELSE
348  mi = m
349  icc = ic
350  jaa = ja + n - l
351  CALL pb_topset( ictxt, 'Broadcast', 'Rowwise', ' ' )
352  IF( notran ) THEN
353  CALL pb_topset( ictxt, 'Broadcast', 'Columnwise', 'I-ring' )
354  ELSE
355  CALL pb_topset( ictxt, 'Broadcast', 'Columnwise', 'D-ring' )
356  END IF
357  END IF
358 *
359  DO 10 i = i1, i2, i3
360  IF( left ) THEN
361 *
362 * H(i) or H(i)' is applied to C(ic+i-ia:icc+m-1,jc:jc+n-1)
363 *
364  mi = m - i + ia
365  icc = ic + i - ia
366  ELSE
367 *
368 * H(i) or H(i)' is applied to C(ic:ic+m-1,jc+i-ia:jc+n-1)
369 *
370  ni = n - i + ia
371  jcc = jc + i - ia
372  END IF
373 *
374 * Apply H(i) or H(i)'
375 *
376  IF( notran ) THEN
377  CALL pzlarz( side, mi, ni, l, a, i, jaa, desca, desca( m_ ),
378  $ tau, c, icc, jcc, descc, work )
379  ELSE
380  CALL pzlarzc( side, mi, ni, l, a, i, jaa, desca,
381  $ desca( m_ ), tau, c, icc, jcc, descc, work )
382  END IF
383 *
384  10 CONTINUE
385 *
386  CALL pb_topset( ictxt, 'Broadcast', 'Rowwise', rowbtop )
387  CALL pb_topset( ictxt, 'Broadcast', 'Columnwise', colbtop )
388 *
389  work( 1 ) = dcmplx( dble( lwmin ) )
390 *
391  RETURN
392 *
393 * End of PZUNMR3
394 *
395  END
max
#define max(A, B)
Definition: pcgemr.c:180
pzunmr3
subroutine pzunmr3(SIDE, TRANS, M, N, K, L, A, IA, JA, DESCA, TAU, C, IC, JC, DESCC, WORK, LWORK, INFO)
Definition: pzunmr3.f:3
pzlarzc
subroutine pzlarzc(SIDE, M, N, L, V, IV, JV, DESCV, INCV, TAU, C, IC, JC, DESCC, WORK)
Definition: pzlarzc.f:3
pzlarz
subroutine pzlarz(SIDE, M, N, L, V, IV, JV, DESCV, INCV, TAU, C, IC, JC, DESCC, WORK)
Definition: pzlarz.f:3
chk1mat
subroutine chk1mat(MA, MAPOS0, NA, NAPOS0, IA, JA, DESCA, DESCAPOS0, INFO)
Definition: chk1mat.f:3
pxerbla
subroutine pxerbla(ICTXT, SRNAME, INFO)
Definition: pxerbla.f:2