SCALAPACK 2.2.2
LAPACK: Linear Algebra PACKage
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pclarzc.f
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1 SUBROUTINE pclarzc( SIDE, M, N, L, V, IV, JV, DESCV, INCV, TAU, C,
2 $ IC, JC, DESCC, WORK )
3*
4* -- ScaLAPACK auxiliary 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
11 INTEGER IC, INCV, IV, JC, JV, L, M, N
12* ..
13* .. Array Arguments ..
14 INTEGER DESCC( * ), DESCV( * )
15 COMPLEX C( * ), TAU( * ), V( * ), WORK( * )
16* ..
17*
18* Purpose
19* =======
20*
21* PCLARZC applies a complex elementary reflector Q**H to a
22* complex M-by-N distributed matrix sub( C ) = C(IC:IC+M-1,JC:JC+N-1),
23* from either the left or the right. Q is represented in the form
24*
25* Q = I - tau * v * v'
26*
27* where tau is a complex scalar and v is a complex vector.
28*
29* If tau = 0, then Q is taken to be the unit matrix.
30*
31* Q is a product of k elementary reflectors as returned by PCTZRZF.
32*
33* Notes
34* =====
35*
36* Each global data object is described by an associated description
37* vector. This vector stores the information required to establish
38* the mapping between an object element and its corresponding process
39* and memory location.
40*
41* Let A be a generic term for any 2D block cyclicly distributed array.
42* Such a global array has an associated description vector DESCA.
43* In the following comments, the character _ should be read as
44* "of the global array".
45*
46* NOTATION STORED IN EXPLANATION
47* --------------- -------------- --------------------------------------
48* DTYPE_A(global) DESCA( DTYPE_ )The descriptor type. In this case,
49* DTYPE_A = 1.
50* CTXT_A (global) DESCA( CTXT_ ) The BLACS context handle, indicating
51* the BLACS process grid A is distribu-
52* ted over. The context itself is glo-
53* bal, but the handle (the integer
54* value) may vary.
55* M_A (global) DESCA( M_ ) The number of rows in the global
56* array A.
57* N_A (global) DESCA( N_ ) The number of columns in the global
58* array A.
59* MB_A (global) DESCA( MB_ ) The blocking factor used to distribute
60* the rows of the array.
61* NB_A (global) DESCA( NB_ ) The blocking factor used to distribute
62* the columns of the array.
63* RSRC_A (global) DESCA( RSRC_ ) The process row over which the first
64* row of the array A is distributed.
65* CSRC_A (global) DESCA( CSRC_ ) The process column over which the
66* first column of the array A is
67* distributed.
68* LLD_A (local) DESCA( LLD_ ) The leading dimension of the local
69* array. LLD_A >= MAX(1,LOCr(M_A)).
70*
71* Let K be the number of rows or columns of a distributed matrix,
72* and assume that its process grid has dimension p x q.
73* LOCr( K ) denotes the number of elements of K that a process
74* would receive if K were distributed over the p processes of its
75* process column.
76* Similarly, LOCc( K ) denotes the number of elements of K that a
77* process would receive if K were distributed over the q processes of
78* its process row.
79* The values of LOCr() and LOCc() may be determined via a call to the
80* ScaLAPACK tool function, NUMROC:
81* LOCr( M ) = NUMROC( M, MB_A, MYROW, RSRC_A, NPROW ),
82* LOCc( N ) = NUMROC( N, NB_A, MYCOL, CSRC_A, NPCOL ).
83* An upper bound for these quantities may be computed by:
84* LOCr( M ) <= ceil( ceil(M/MB_A)/NPROW )*MB_A
85* LOCc( N ) <= ceil( ceil(N/NB_A)/NPCOL )*NB_A
86*
87* Because vectors may be viewed as a subclass of matrices, a
88* distributed vector is considered to be a distributed matrix.
89*
90* Restrictions
91* ============
92*
93* If SIDE = 'Left' and INCV = 1, then the row process having the first
94* entry V(IV,JV) must also own C(IC+M-L,JC:JC+N-1). Moreover,
95* MOD(IV-1,MB_V) must be equal to MOD(IC+N-L-1,MB_C), if INCV=M_V, only
96* the last equality must be satisfied.
97*
98* If SIDE = 'Right' and INCV = M_V then the column process having the
99* first entry V(IV,JV) must also own C(IC:IC+M-1,JC+N-L) and
100* MOD(JV-1,NB_V) must be equal to MOD(JC+N-L-1,NB_C), if INCV = 1 only
101* the last equality must be satisfied.
102*
103* Arguments
104* =========
105*
106* SIDE (global input) CHARACTER
107* = 'L': form Q**H * sub( C ),
108* = 'R': form sub( C ) * Q**H.
109*
110* M (global input) INTEGER
111* The number of rows to be operated on i.e the number of rows
112* of the distributed submatrix sub( C ). M >= 0.
113*
114* N (global input) INTEGER
115* The number of columns to be operated on i.e the number of
116* columns of the distributed submatrix sub( C ). N >= 0.
117*
118* L (global input) INTEGER
119* The columns of the distributed submatrix sub( A ) containing
120* the meaningful part of the Householder reflectors.
121* If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0.
122*
123* V (local input) COMPLEX pointer into the local memory
124* to an array of dimension (LLD_V,*) containing the local
125* pieces of the distributed vectors V representing the
126* Householder transformation Q,
127* V(IV:IV+L-1,JV) if SIDE = 'L' and INCV = 1,
128* V(IV,JV:JV+L-1) if SIDE = 'L' and INCV = M_V,
129* V(IV:IV+L-1,JV) if SIDE = 'R' and INCV = 1,
130* V(IV,JV:JV+L-1) if SIDE = 'R' and INCV = M_V,
131*
132* The vector v in the representation of Q. V is not used if
133* TAU = 0.
134*
135* IV (global input) INTEGER
136* The row index in the global array V indicating the first
137* row of sub( V ).
138*
139* JV (global input) INTEGER
140* The column index in the global array V indicating the
141* first column of sub( V ).
142*
143* DESCV (global and local input) INTEGER array of dimension DLEN_.
144* The array descriptor for the distributed matrix V.
145*
146* INCV (global input) INTEGER
147* The global increment for the elements of V. Only two values
148* of INCV are supported in this version, namely 1 and M_V.
149* INCV must not be zero.
150*
151* TAU (local input) COMPLEX, array, dimension LOCc(JV) if
152* INCV = 1, and LOCr(IV) otherwise. This array contains the
153* Householder scalars related to the Householder vectors.
154* TAU is tied to the distributed matrix V.
155*
156* C (local input/local output) COMPLEX pointer into the
157* local memory to an array of dimension (LLD_C, LOCc(JC+N-1) ),
158* containing the local pieces of sub( C ). On exit, sub( C )
159* is overwritten by the Q**H * sub( C ) if SIDE = 'L', or
160* sub( C ) * Q**H if SIDE = 'R'.
161*
162* IC (global input) INTEGER
163* The row index in the global array C indicating the first
164* row of sub( C ).
165*
166* JC (global input) INTEGER
167* The column index in the global array C indicating the
168* first column of sub( C ).
169*
170* DESCC (global and local input) INTEGER array of dimension DLEN_.
171* The array descriptor for the distributed matrix C.
172*
173* WORK (local workspace) COMPLEX array, dimension (LWORK)
174* If INCV = 1,
175* if SIDE = 'L',
176* if IVCOL = ICCOL,
177* LWORK >= NqC0
178* else
179* LWORK >= MpC0 + MAX( 1, NqC0 )
180* end if
181* else if SIDE = 'R',
182* LWORK >= NqC0 + MAX( MAX( 1, MpC0 ), NUMROC( NUMROC(
183* N+ICOFFC,NB_V,0,0,NPCOL ),NB_V,0,0,LCMQ ) )
184* end if
185* else if INCV = M_V,
186* if SIDE = 'L',
187* LWORK >= MpC0 + MAX( MAX( 1, NqC0 ), NUMROC( NUMROC(
188* M+IROFFC,MB_V,0,0,NPROW ),MB_V,0,0,LCMP ) )
189* else if SIDE = 'R',
190* if IVROW = ICROW,
191* LWORK >= MpC0
192* else
193* LWORK >= NqC0 + MAX( 1, MpC0 )
194* end if
195* end if
196* end if
197*
198* where LCM is the least common multiple of NPROW and NPCOL and
199* LCM = ILCM( NPROW, NPCOL ), LCMP = LCM / NPROW,
200* LCMQ = LCM / NPCOL,
201*
202* IROFFC = MOD( IC-1, MB_C ), ICOFFC = MOD( JC-1, NB_C ),
203* ICROW = INDXG2P( IC, MB_C, MYROW, RSRC_C, NPROW ),
204* ICCOL = INDXG2P( JC, NB_C, MYCOL, CSRC_C, NPCOL ),
205* MpC0 = NUMROC( M+IROFFC, MB_C, MYROW, ICROW, NPROW ),
206* NqC0 = NUMROC( N+ICOFFC, NB_C, MYCOL, ICCOL, NPCOL ),
207*
208* ILCM, INDXG2P and NUMROC are ScaLAPACK tool functions;
209* MYROW, MYCOL, NPROW and NPCOL can be determined by calling
210* the subroutine BLACS_GRIDINFO.
211*
212* Alignment requirements
213* ======================
214*
215* The distributed submatrices V(IV:*, JV:*) and C(IC:IC+M-1,JC:JC+N-1)
216* must verify some alignment properties, namely the following
217* expressions should be true:
218*
219* MB_V = NB_V,
220*
221* If INCV = 1,
222* If SIDE = 'Left',
223* ( MB_V.EQ.MB_C .AND. IROFFV.EQ.IROFFC .AND. IVROW.EQ.ICROW )
224* If SIDE = 'Right',
225* ( MB_V.EQ.NB_A .AND. MB_V.EQ.NB_C .AND. IROFFV.EQ.ICOFFC )
226* else if INCV = M_V,
227* If SIDE = 'Left',
228* ( MB_V.EQ.NB_V .AND. MB_V.EQ.MB_C .AND. ICOFFV.EQ.IROFFC )
229* If SIDE = 'Right',
230* ( NB_V.EQ.NB_C .AND. ICOFFV.EQ.ICOFFC .AND. IVCOL.EQ.ICCOL )
231* end if
232*
233* =====================================================================
234*
235* .. Parameters ..
236 INTEGER BLOCK_CYCLIC_2D, CSRC_, CTXT_, DLEN_, DTYPE_,
237 $ lld_, mb_, m_, nb_, n_, rsrc_
238 parameter( block_cyclic_2d = 1, dlen_ = 9, dtype_ = 1,
239 $ ctxt_ = 2, m_ = 3, n_ = 4, mb_ = 5, nb_ = 6,
240 $ rsrc_ = 7, csrc_ = 8, lld_ = 9 )
241 COMPLEX ONE, ZERO
242 parameter( one = ( 1.0e+0, 0.0e+0 ),
243 $ zero = ( 0.0e+0, 0.0e+0 ) )
244* ..
245* .. Local Scalars ..
246 LOGICAL CCBLCK, CRBLCK, LEFT
247 CHARACTER COLBTOP, ROWBTOP
248 INTEGER ICCOL1, ICCOL2, ICOFFC1, ICOFFC2, ICOFFV,
249 $ icrow1, icrow2, ictxt, iic1, iic2, iiv, ioffc1,
250 $ ioffc2, ioffv, ipw, iroffc1, iroffc2, iroffv,
251 $ ivcol, ivrow, jjc1, jjc2, jjv, ldc, ldv, mpc2,
252 $ mpv, mycol, myrow, ncc, ncv, npcol, nprow,
253 $ nqc2, nqv, rdest
254 COMPLEX TAULOC( 1 )
255* ..
256* .. External Subroutines ..
257 EXTERNAL blacs_gridinfo, caxpy, ccopy, cgebr2d,
258 $ cgebs2d, cgemv, cgerc, cgerv2d,
259 $ cgesd2d, cgsum2d, claset, infog2l,
260 $ pb_topget, pbctrnv
261* ..
262* .. External Functions ..
263 LOGICAL LSAME
264 INTEGER NUMROC
265 EXTERNAL lsame, numroc
266* ..
267* .. Intrinsic Functions ..
268 INTRINSIC min, mod
269* ..
270* .. Executable Statements ..
271*
272* Quick return if possible
273*
274 IF( m.LE.0 .OR. n.LE.0 )
275 $ RETURN
276*
277* Get grid parameters.
278*
279 ictxt = descc( ctxt_ )
280 CALL blacs_gridinfo( ictxt, nprow, npcol, myrow, mycol )
281*
282* Figure local indexes
283*
284 left = lsame( side, 'L' )
285 CALL infog2l( iv, jv, descv, nprow, npcol, myrow, mycol, iiv, jjv,
286 $ ivrow, ivcol )
287 iroffv = mod( iv-1, descv( nb_ ) )
288 mpv = numroc( l+iroffv, descv( mb_ ), myrow, ivrow, nprow )
289 IF( myrow.EQ.ivrow )
290 $ mpv = mpv - iroffv
291 icoffv = mod( jv-1, descv( nb_ ) )
292 nqv = numroc( l+icoffv, descv( nb_ ), mycol, ivcol, npcol )
293 IF( mycol.EQ.ivcol )
294 $ nqv = nqv - icoffv
295 ldv = descv( lld_ )
296 ncv = numroc( descv( n_ ), descv( nb_ ), mycol, descv( csrc_ ),
297 $ npcol )
298 ldv = descv( lld_ )
299 iiv = min( iiv, ldv )
300 jjv = min( jjv, ncv )
301 ioffv = iiv+(jjv-1)*ldv
302 ncc = numroc( descc( n_ ), descc( nb_ ), mycol, descc( csrc_ ),
303 $ npcol )
304 CALL infog2l( ic, jc, descc, nprow, npcol, myrow, mycol,
305 $ iic1, jjc1, icrow1, iccol1 )
306 iroffc1 = mod( ic-1, descc( mb_ ) )
307 icoffc1 = mod( jc-1, descc( nb_ ) )
308 ldc = descc( lld_ )
309 iic1 = min( iic1, ldc )
310 jjc1 = min( jjc1, max( 1, ncc ) )
311 ioffc1 = iic1 + ( jjc1-1 ) * ldc
312*
313 IF( left ) THEN
314 CALL infog2l( ic+m-l, jc, descc, nprow, npcol, myrow, mycol,
315 $ iic2, jjc2, icrow2, iccol2 )
316 iroffc2 = mod( ic+m-l-1, descc( mb_ ) )
317 icoffc2 = mod( jc-1, descc( nb_ ) )
318 nqc2 = numroc( n+icoffc2, descc( nb_ ), mycol, iccol2, npcol )
319 IF( mycol.EQ.iccol2 )
320 $ nqc2 = nqc2 - icoffc2
321 ELSE
322 CALL infog2l( ic, jc+n-l, descc, nprow, npcol, myrow, mycol,
323 $ iic2, jjc2, icrow2, iccol2 )
324 iroffc2 = mod( ic-1, descc( mb_ ) )
325 mpc2 = numroc( m+iroffc2, descc( mb_ ), myrow, icrow2, nprow )
326 IF( myrow.EQ.icrow2 )
327 $ mpc2 = mpc2 - iroffc2
328 icoffc2 = mod( jc+n-l-1, descc( nb_ ) )
329 END IF
330 iic2 = min( iic2, ldc )
331 jjc2 = min( jjc2, ncc )
332 ioffc2 = iic2 + ( jjc2-1 ) * ldc
333*
334* Is sub( C ) only distributed over a process row ?
335*
336 crblck = ( m.LE.(descc( mb_ )-iroffc1) )
337*
338* Is sub( C ) only distributed over a process column ?
339*
340 ccblck = ( n.LE.(descc( nb_ )-icoffc1) )
341*
342 IF( left ) THEN
343*
344 IF( crblck ) THEN
345 rdest = icrow2
346 ELSE
347 rdest = -1
348 END IF
349*
350 IF( ccblck ) THEN
351*
352* sub( C ) is distributed over a process column
353*
354 IF( descv( m_ ).EQ.incv ) THEN
355*
356* Transpose row vector V (ICOFFV = IROFFC2)
357*
358 ipw = mpv+1
359 CALL pbctrnv( ictxt, 'Rowwise', 'Transpose', m,
360 $ descv( nb_ ), iroffc2, v( ioffv ), ldv,
361 $ zero,
362 $ work, 1, ivrow, ivcol, icrow2, iccol2,
363 $ work( ipw ) )
364*
365* Perform the local computation within a process column
366*
367 IF( mycol.EQ.iccol2 ) THEN
368*
369 IF( myrow.EQ.ivrow ) THEN
370*
371 CALL cgebs2d( ictxt, 'Columnwise', ' ', 1, 1,
372 $ tau( iiv ), 1 )
373 tauloc( 1 ) = conjg( tau( iiv ) )
374*
375 ELSE
376*
377 CALL cgebr2d( ictxt, 'Columnwise', ' ', 1, 1,
378 $ tauloc, 1, ivrow, mycol )
379 tauloc( 1 ) = conjg( tauloc( 1 ) )
380*
381 END IF
382*
383 IF( tauloc( 1 ).NE.zero ) THEN
384*
385* w := sub( C )' * v
386*
387 IF( mpv.GT.0 ) THEN
388 CALL cgemv( 'Conjugate transpose', mpv, nqc2,
389 $ one, c( ioffc2 ), ldc, work, 1,
390 $ zero, work( ipw ), 1 )
391 ELSE
392 CALL claset( 'All', nqc2, 1, zero, zero,
393 $ work( ipw ), max( 1, nqc2 ) )
394 END IF
395 IF( myrow.EQ.icrow1 )
396 $ CALL caxpy( nqc2, one, c( ioffc1 ), ldc,
397 $ work( ipw ), max( 1, nqc2 ) )
398*
399 CALL cgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
400 $ work( ipw ), max( 1, nqc2 ), rdest,
401 $ mycol )
402*
403* sub( C ) := sub( C ) - v * w'
404*
405 IF( myrow.EQ.icrow1 )
406 $ CALL caxpy( nqc2, -tauloc( 1 ), work( ipw ),
407 $ max( 1, nqc2 ), c( ioffc1 ), ldc )
408 CALL cgerc( mpv, nqc2, -tauloc( 1 ), work, 1,
409 $ work( ipw ), 1, c( ioffc2 ), ldc )
410 END IF
411*
412 END IF
413*
414 ELSE
415*
416* V is a column vector
417*
418 IF( ivcol.EQ.iccol2 ) THEN
419*
420* Perform the local computation within a process column
421*
422 IF( mycol.EQ.iccol2 ) THEN
423*
424 tauloc( 1 ) = conjg( tau( jjv ) )
425*
426 IF( tauloc( 1 ).NE.zero ) THEN
427*
428* w := sub( C )' * v
429*
430 IF( mpv.GT.0 ) THEN
431 CALL cgemv( 'Conjugate transpose', mpv, nqc2,
432 $ one, c( ioffc2 ), ldc, v( ioffv ),
433 $ 1, zero, work, 1 )
434 ELSE
435 CALL claset( 'All', nqc2, 1, zero, zero,
436 $ work, max( 1, nqc2 ) )
437 END IF
438 IF( myrow.EQ.icrow1 )
439 $ CALL caxpy( nqc2, one, c( ioffc1 ), ldc,
440 $ work, max( 1, nqc2 ) )
441*
442 CALL cgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
443 $ work, max( 1, nqc2 ), rdest,
444 $ mycol )
445*
446* sub( C ) := sub( C ) - v * w'
447*
448 IF( myrow.EQ.icrow1 )
449 $ CALL caxpy( nqc2, -tauloc( 1 ), work,
450 $ max( 1, nqc2 ), c( ioffc1 ),
451 $ ldc )
452 CALL cgerc( mpv, nqc2, -tauloc( 1 ), v( ioffv ),
453 $ 1, work, 1, c( ioffc2 ), ldc )
454 END IF
455*
456 END IF
457*
458 ELSE
459*
460* Send V and TAU to the process column ICCOL2
461*
462 IF( mycol.EQ.ivcol ) THEN
463*
464 ipw = mpv+1
465 CALL ccopy( mpv, v( ioffv ), 1, work, 1 )
466 work( ipw ) = tau( jjv )
467 CALL cgesd2d( ictxt, ipw, 1, work, ipw, myrow,
468 $ iccol2 )
469*
470 ELSE IF( mycol.EQ.iccol2 ) THEN
471*
472 ipw = mpv+1
473 CALL cgerv2d( ictxt, ipw, 1, work, ipw, myrow,
474 $ ivcol )
475 tauloc( 1 ) = conjg( work( ipw ) )
476*
477 IF( tauloc( 1 ).NE.zero ) THEN
478*
479* w := sub( C )' * v
480*
481 IF( mpv.GT.0 ) THEN
482 CALL cgemv( 'Conjugate transpose', mpv, nqc2,
483 $ one, c( ioffc2 ), ldc, work, 1,
484 $ zero, work( ipw ), 1 )
485 ELSE
486 CALL claset( 'All', nqc2, 1, zero, zero,
487 $ work( ipw ), max( 1, nqc2 ) )
488 END IF
489 IF( myrow.EQ.icrow1 )
490 $ CALL caxpy( nqc2, one, c( ioffc1 ), ldc,
491 $ work( ipw ), max( 1, nqc2 ) )
492*
493 CALL cgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
494 $ work( ipw ), max( 1, nqc2 ),
495 $ rdest, mycol )
496*
497* sub( C ) := sub( C ) - v * w'
498*
499 IF( myrow.EQ.icrow1 )
500 $ CALL caxpy( nqc2, -tauloc( 1 ), work( ipw ),
501 $ max( 1, nqc2 ), c( ioffc1 ),
502 $ ldc )
503 CALL cgerc( mpv, nqc2, -tauloc( 1 ), work, 1,
504 $ work( ipw ), 1, c( ioffc2 ), ldc )
505 END IF
506*
507 END IF
508*
509 END IF
510*
511 END IF
512*
513 ELSE
514*
515* sub( C ) is a proper distributed matrix
516*
517 IF( descv( m_ ).EQ.incv ) THEN
518*
519* Transpose and broadcast row vector V (ICOFFV=IROFFC2)
520*
521 ipw = mpv+1
522 CALL pbctrnv( ictxt, 'Rowwise', 'Transpose', m,
523 $ descv( nb_ ), iroffc2, v( ioffv ), ldv,
524 $ zero,
525 $ work, 1, ivrow, ivcol, icrow2, -1,
526 $ work( ipw ) )
527*
528* Perform the local computation within a process column
529*
530 IF( myrow.EQ.ivrow ) THEN
531*
532 CALL cgebs2d( ictxt, 'Columnwise', ' ', 1, 1,
533 $ tau( iiv ), 1 )
534 tauloc( 1 ) = conjg( tau( iiv ) )
535*
536 ELSE
537*
538 CALL cgebr2d( ictxt, 'Columnwise', ' ', 1, 1, tauloc,
539 $ 1, ivrow, mycol )
540 tauloc( 1 ) = conjg( tauloc( 1 ) )
541*
542 END IF
543*
544 IF( tauloc( 1 ).NE.zero ) THEN
545*
546* w := sub( C )' * v
547*
548 IF( mpv.GT.0 ) THEN
549 CALL cgemv( 'Conjugate transpose', mpv, nqc2, one,
550 $ c( ioffc2 ), ldc, work, 1, zero,
551 $ work( ipw ), 1 )
552 ELSE
553 CALL claset( 'All', nqc2, 1, zero, zero,
554 $ work( ipw ), max( 1, nqc2 ) )
555 END IF
556 IF( myrow.EQ.icrow1 )
557 $ CALL caxpy( nqc2, one, c( ioffc1 ), ldc,
558 $ work( ipw ), max( 1, nqc2 ) )
559*
560 CALL cgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
561 $ work( ipw ), max( 1, nqc2 ), rdest,
562 $ mycol )
563*
564* sub( C ) := sub( C ) - v * w'
565*
566 IF( myrow.EQ.icrow1 )
567 $ CALL caxpy( nqc2, -tauloc( 1 ), work( ipw ),
568 $ max( 1, nqc2 ), c( ioffc1 ), ldc )
569 CALL cgerc( mpv, nqc2, -tauloc( 1 ), work, 1,
570 $ work( ipw ), 1, c( ioffc2 ), ldc )
571 END IF
572*
573 ELSE
574*
575* Broadcast column vector V
576*
577 CALL pb_topget( ictxt, 'Broadcast', 'Rowwise', rowbtop )
578 IF( mycol.EQ.ivcol ) THEN
579*
580 ipw = mpv+1
581 CALL ccopy( mpv, v( ioffv ), 1, work, 1 )
582 work( ipw ) = tau( jjv )
583 CALL cgebs2d( ictxt, 'Rowwise', rowbtop, ipw, 1,
584 $ work, ipw )
585 tauloc( 1 ) = conjg( tau( jjv ) )
586*
587 ELSE
588*
589 ipw = mpv+1
590 CALL cgebr2d( ictxt, 'Rowwise', rowbtop, ipw, 1, work,
591 $ ipw, myrow, ivcol )
592 tauloc( 1 ) = conjg( work( ipw ) )
593*
594 END IF
595*
596 IF( tauloc( 1 ).NE.zero ) THEN
597*
598* w := sub( C )' * v
599*
600 IF( mpv.GT.0 ) THEN
601 CALL cgemv( 'Conjugate transpose', mpv, nqc2, one,
602 $ c( ioffc2 ), ldc, work, 1, zero,
603 $ work( ipw ), 1 )
604 ELSE
605 CALL claset( 'All', nqc2, 1, zero, zero,
606 $ work( ipw ), max( 1, nqc2 ) )
607 END IF
608 IF( myrow.EQ.icrow1 )
609 $ CALL caxpy( nqc2, one, c( ioffc1 ), ldc,
610 $ work( ipw ), max( 1, nqc2 ) )
611*
612 CALL cgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
613 $ work( ipw ), max( 1, nqc2 ), rdest,
614 $ mycol )
615*
616* sub( C ) := sub( C ) - v * w'
617*
618 IF( myrow.EQ.icrow1 )
619 $ CALL caxpy( nqc2, -tauloc( 1 ), work( ipw ),
620 $ max( 1, nqc2 ), c( ioffc1 ), ldc )
621 CALL cgerc( mpv, nqc2, -tauloc( 1 ), work, 1,
622 $ work( ipw ), 1, c( ioffc2 ), ldc )
623 END IF
624*
625 END IF
626*
627 END IF
628*
629 ELSE
630*
631 IF( ccblck ) THEN
632 rdest = myrow
633 ELSE
634 rdest = -1
635 END IF
636*
637 IF( crblck ) THEN
638*
639* sub( C ) is distributed over a process row
640*
641 IF( descv( m_ ).EQ.incv ) THEN
642*
643* V is a row vector
644*
645 IF( ivrow.EQ.icrow2 ) THEN
646*
647* Perform the local computation within a process row
648*
649 IF( myrow.EQ.icrow2 ) THEN
650*
651 tauloc( 1 ) = conjg( tau( iiv ) )
652*
653 IF( tauloc( 1 ).NE.zero ) THEN
654*
655* w := sub( C ) * v
656*
657 IF( nqv.GT.0 ) THEN
658 CALL cgemv( 'No transpose', mpc2, nqv, one,
659 $ c( ioffc2 ), ldc, v( ioffv ),
660 $ ldv, zero, work, 1 )
661 ELSE
662 CALL claset( 'All', mpc2, 1, zero, zero,
663 $ work, max( 1, mpc2 ) )
664 END IF
665 IF( mycol.EQ.iccol1 )
666 $ CALL caxpy( mpc2, one, c( ioffc1 ), 1,
667 $ work, 1 )
668*
669 CALL cgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
670 $ work, max( 1, mpc2 ), rdest,
671 $ iccol2 )
672*
673 IF( mycol.EQ.iccol1 )
674 $ CALL caxpy( mpc2, -tauloc( 1 ), work, 1,
675 $ c( ioffc1 ), 1 )
676*
677* sub( C ) := sub( C ) - w * v'
678*
679 CALL cgerc( mpc2, nqv, -tauloc( 1 ), work, 1,
680 $ v( ioffv ), ldv, c( ioffc2 ), ldc )
681 END IF
682*
683 END IF
684*
685 ELSE
686*
687* Send V and TAU to the process row ICROW2
688*
689 IF( myrow.EQ.ivrow ) THEN
690*
691 ipw = nqv+1
692 CALL ccopy( nqv, v( ioffv ), ldv, work, 1 )
693 work( ipw ) = tau( iiv )
694 CALL cgesd2d( ictxt, ipw, 1, work, ipw, icrow2,
695 $ mycol )
696*
697 ELSE IF( myrow.EQ.icrow2 ) THEN
698*
699 ipw = nqv+1
700 CALL cgerv2d( ictxt, ipw, 1, work, ipw, ivrow,
701 $ mycol )
702 tauloc( 1 ) = conjg( work( ipw ) )
703*
704 IF( tauloc( 1 ).NE.zero ) THEN
705*
706* w := sub( C ) * v
707*
708 IF( nqv.GT.0 ) THEN
709 CALL cgemv( 'No transpose', mpc2, nqv, one,
710 $ c( ioffc2 ), ldc, work, 1, zero,
711 $ work( ipw ), 1 )
712 ELSE
713 CALL claset( 'All', mpc2, 1, zero, zero,
714 $ work( ipw ), max( 1, mpc2 ) )
715 END IF
716 IF( mycol.EQ.iccol1 )
717 $ CALL caxpy( mpc2, one, c( ioffc1 ), 1,
718 $ work( ipw ), 1 )
719 CALL cgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
720 $ work( ipw ), max( 1, mpc2 ),
721 $ rdest, iccol2 )
722 IF( mycol.EQ.iccol1 )
723 $ CALL caxpy( mpc2, -tauloc( 1 ), work( ipw ),
724 $ 1, c( ioffc1 ), 1 )
725*
726* sub( C ) := sub( C ) - w * v'
727*
728 CALL cgerc( mpc2, nqv, -tauloc( 1 ),
729 $ work( ipw ), 1, work, 1,
730 $ c( ioffc2 ), ldc )
731 END IF
732*
733 END IF
734*
735 END IF
736*
737 ELSE
738*
739* Transpose column vector V (IROFFV = ICOFFC2)
740*
741 ipw = nqv+1
742 CALL pbctrnv( ictxt, 'Columnwise', 'Transpose', n,
743 $ descv( mb_ ), icoffc2, v( ioffv ), 1, zero,
744 $ work, 1, ivrow, ivcol, icrow2, iccol2,
745 $ work( ipw ) )
746*
747* Perform the local computation within a process column
748*
749 IF( myrow.EQ.icrow2 ) THEN
750*
751 IF( mycol.EQ.ivcol ) THEN
752*
753 CALL cgebs2d( ictxt, 'Rowwise', ' ', 1, 1,
754 $ tau( jjv ), 1 )
755 tauloc( 1 ) = conjg( tau( jjv ) )
756*
757 ELSE
758*
759 CALL cgebr2d( ictxt, 'Rowwise', ' ', 1, 1, tauloc,
760 $ 1, myrow, ivcol )
761 tauloc( 1 ) = conjg( tauloc( 1 ) )
762*
763 END IF
764*
765 IF( tauloc( 1 ).NE.zero ) THEN
766*
767* w := sub( C ) * v
768*
769 IF( nqv.GT.0 ) THEN
770 CALL cgemv( 'No transpose', mpc2, nqv, one,
771 $ c( ioffc2 ), ldc, work, 1, zero,
772 $ work( ipw ), 1 )
773 ELSE
774 CALL claset( 'All', mpc2, 1, zero, zero,
775 $ work( ipw ), max( 1, mpc2 ) )
776 END IF
777 IF( mycol.EQ.iccol1 )
778 $ CALL caxpy( mpc2, one, c( ioffc1 ), 1,
779 $ work( ipw ), 1 )
780 CALL cgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
781 $ work( ipw ), max( 1, mpc2 ), rdest,
782 $ iccol2 )
783 IF( mycol.EQ.iccol1 )
784 $ CALL caxpy( mpc2, -tauloc( 1 ), work( ipw ), 1,
785 $ c( ioffc1 ), 1 )
786*
787* sub( C ) := sub( C ) - w * v'
788*
789 CALL cgerc( mpc2, nqv, -tauloc( 1 ), work( ipw ),
790 $ 1, work, 1, c( ioffc2 ), ldc )
791 END IF
792*
793 END IF
794*
795 END IF
796*
797 ELSE
798*
799* sub( C ) is a proper distributed matrix
800*
801 IF( descv( m_ ).EQ.incv ) THEN
802*
803* Broadcast row vector V
804*
805 CALL pb_topget( ictxt, 'Broadcast', 'Columnwise',
806 $ colbtop )
807 IF( myrow.EQ.ivrow ) THEN
808*
809 ipw = nqv+1
810 CALL ccopy( nqv, v( ioffv ), ldv, work, 1 )
811 work( ipw ) = tau( iiv )
812 CALL cgebs2d( ictxt, 'Columnwise', colbtop, ipw, 1,
813 $ work, ipw )
814 tauloc( 1 ) = conjg( tau( iiv ) )
815*
816 ELSE
817*
818 ipw = nqv+1
819 CALL cgebr2d( ictxt, 'Columnwise', colbtop, ipw, 1,
820 $ work, ipw, ivrow, mycol )
821 tauloc( 1 ) = conjg( work( ipw ) )
822*
823 END IF
824*
825 IF( tauloc( 1 ).NE.zero ) THEN
826*
827* w := sub( C ) * v
828*
829 IF( nqv.GT.0 ) THEN
830 CALL cgemv( 'No Transpose', mpc2, nqv, one,
831 $ c( ioffc2 ), ldc, work, 1, zero,
832 $ work( ipw ), 1 )
833 ELSE
834 CALL claset( 'All', mpc2, 1, zero, zero,
835 $ work( ipw ), max( 1, mpc2 ) )
836 END IF
837 IF( mycol.EQ.iccol1 )
838 $ CALL caxpy( mpc2, one, c( ioffc1 ), 1,
839 $ work( ipw ), 1 )
840*
841 CALL cgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
842 $ work( ipw ), max( 1, mpc2 ), rdest,
843 $ iccol2 )
844 IF( mycol.EQ.iccol1 )
845 $ CALL caxpy( mpc2, -tauloc( 1 ), work( ipw ), 1,
846 $ c( ioffc1 ), 1 )
847*
848* sub( C ) := sub( C ) - w * v'
849*
850 CALL cgerc( mpc2, nqv, -tauloc( 1 ), work( ipw ), 1,
851 $ work, 1, c( ioffc2 ), ldc )
852 END IF
853*
854 ELSE
855*
856* Transpose and broadcast column vector V (ICOFFC2=IROFFV)
857*
858 ipw = nqv+1
859 CALL pbctrnv( ictxt, 'Columnwise', 'Transpose', n,
860 $ descv( mb_ ), icoffc2, v( ioffv ), 1, zero,
861 $ work, 1, ivrow, ivcol, -1, iccol2,
862 $ work( ipw ) )
863*
864* Perform the local computation within a process column
865*
866 IF( mycol.EQ.ivcol ) THEN
867*
868 CALL cgebs2d( ictxt, 'Rowwise', ' ', 1, 1, tau( jjv ),
869 $ 1 )
870 tauloc( 1 ) = conjg( tau( jjv ) )
871*
872 ELSE
873*
874 CALL cgebr2d( ictxt, 'Rowwise', ' ', 1, 1,
875 $ tauloc( 1 ), 1, myrow, ivcol )
876 tauloc( 1 ) = conjg( tauloc( 1 ) )
877*
878 END IF
879*
880 IF( tauloc( 1 ).NE.zero ) THEN
881*
882* w := sub( C ) * v
883*
884 IF( nqv.GT.0 ) THEN
885 CALL cgemv( 'No transpose', mpc2, nqv, one,
886 $ c( ioffc2 ), ldc, work, 1, zero,
887 $ work( ipw ), 1 )
888 ELSE
889 CALL claset( 'All', mpc2, 1, zero, zero,
890 $ work( ipw ), max( 1, mpc2 ) )
891 END IF
892 IF( mycol.EQ.iccol1 )
893 $ CALL caxpy( mpc2, one, c( ioffc1 ), 1,
894 $ work( ipw ), 1 )
895 CALL cgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
896 $ work( ipw ), max( 1, mpc2 ), rdest,
897 $ iccol2 )
898 IF( mycol.EQ.iccol1 )
899 $ CALL caxpy( mpc2, -tauloc( 1 ), work( ipw ), 1,
900 $ c( ioffc1 ), 1 )
901*
902* sub( C ) := sub( C ) - w * v'
903*
904 CALL cgerc( mpc2, nqv, -tauloc( 1 ), work( ipw ), 1,
905 $ work, 1, c( ioffc2 ), ldc )
906 END IF
907*
908 END IF
909*
910 END IF
911*
912 END IF
913*
914 RETURN
915*
916* End of PCLARZC
917*
918 END
infog2l
subroutine infog2l(grindx, gcindx, desc, nprow, npcol, myrow, mycol, lrindx, lcindx, rsrc, csrc)
Definition infog2l.f:3
pbctrnv
subroutine pbctrnv(icontxt, xdist, trans, n, nb, nz, x, incx, beta, y, incy, ixrow, ixcol, iyrow, iycol, work)
Definition pbctrnv.f:4
max
#define max(A, B)
Definition pcgemr.c:180
min
#define min(A, B)
Definition pcgemr.c:181
pclarzc
subroutine pclarzc(side, m, n, l, v, iv, jv, descv, incv, tau, c, ic, jc, descc, work)
Definition pclarzc.f:3