SCALAPACK 2.2.2
LAPACK: Linear Algebra PACKage
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pzlarz.f
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1 SUBROUTINE pzlarz( 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*16 C( * ), TAU( * ), V( * ), WORK( * )
16* ..
17*
18* Purpose
19* =======
20*
21* PZLARZ applies a complex elementary reflector Q to a complex M-by-N
22* distributed matrix sub( C ) = C(IC:IC+M-1,JC:JC+N-1), from either the
23* 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 PZTZRZF.
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 * sub( C ),
108* = 'R': form sub( C ) * Q.
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*16 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*16, 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*16 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 * sub( C ) if SIDE = 'L', or
160* sub( C ) * Q 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*16 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*16 ONE, ZERO
242 parameter( one = ( 1.0d+0, 0.0d+0 ),
243 $ zero = ( 0.0d+0, 0.0d+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*16 TAULOC( 1 )
255* ..
256* .. External Subroutines ..
257 EXTERNAL blacs_gridinfo, infog2l, pb_topget, pbztrnv,
258 $ zaxpy, zcopy, zgebr2d, zgebs2d,
259 $ zgemv, zgerc, zgerv2d, zgesd2d,
260 $ zgsum2d, zlaset
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 pbztrnv( 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 zgebs2d( ictxt, 'Columnwise', ' ', 1, 1,
372 $ tau( iiv ), 1 )
373 tauloc( 1 ) = tau( iiv )
374*
375 ELSE
376*
377 CALL zgebr2d( ictxt, 'Columnwise', ' ', 1, 1,
378 $ tauloc, 1, ivrow, mycol )
379*
380 END IF
381*
382 IF( tauloc( 1 ).NE.zero ) THEN
383*
384* w := sub( C )' * v
385*
386 IF( mpv.GT.0 ) THEN
387 CALL zgemv( 'Conjugate transpose', mpv, nqc2,
388 $ one, c( ioffc2 ), ldc, work, 1,
389 $ zero, work( ipw ), 1 )
390 ELSE
391 CALL zlaset( 'All', nqc2, 1, zero, zero,
392 $ work( ipw ), max( 1, nqc2 ) )
393 END IF
394 IF( myrow.EQ.icrow1 )
395 $ CALL zaxpy( nqc2, one, c( ioffc1 ), ldc,
396 $ work( ipw ), max( 1, nqc2 ) )
397*
398 CALL zgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
399 $ work( ipw ), max( 1, nqc2 ), rdest,
400 $ mycol )
401*
402* sub( C ) := sub( C ) - v * w'
403*
404 IF( myrow.EQ.icrow1 )
405 $ CALL zaxpy( nqc2, -tauloc( 1 ), work( ipw ),
406 $ max( 1, nqc2 ), c( ioffc1 ), ldc )
407 CALL zgerc( mpv, nqc2, -tauloc( 1 ), work, 1,
408 $ work( ipw ), 1, c( ioffc2 ), ldc )
409 END IF
410*
411 END IF
412*
413 ELSE
414*
415* V is a column vector
416*
417 IF( ivcol.EQ.iccol2 ) THEN
418*
419* Perform the local computation within a process column
420*
421 IF( mycol.EQ.iccol2 ) THEN
422*
423 tauloc( 1 ) = tau( jjv )
424*
425 IF( tauloc( 1 ).NE.zero ) THEN
426*
427* w := sub( C )' * v
428*
429 IF( mpv.GT.0 ) THEN
430 CALL zgemv( 'Conjugate transpose', mpv, nqc2,
431 $ one, c( ioffc2 ), ldc, v( ioffv ),
432 $ 1, zero, work, 1 )
433 ELSE
434 CALL zlaset( 'All', nqc2, 1, zero, zero,
435 $ work, max( 1, nqc2 ) )
436 END IF
437 IF( myrow.EQ.icrow1 )
438 $ CALL zaxpy( nqc2, one, c( ioffc1 ), ldc,
439 $ work, max( 1, nqc2 ) )
440*
441 CALL zgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
442 $ work, max( 1, nqc2 ), rdest,
443 $ mycol )
444*
445* sub( C ) := sub( C ) - v * w'
446*
447 IF( myrow.EQ.icrow1 )
448 $ CALL zaxpy( nqc2, -tauloc( 1 ), work,
449 $ max( 1, nqc2 ), c( ioffc1 ),
450 $ ldc )
451 CALL zgerc( mpv, nqc2, -tauloc( 1 ), v( ioffv ),
452 $ 1, work, 1, c( ioffc2 ), ldc )
453 END IF
454*
455 END IF
456*
457 ELSE
458*
459* Send V and TAU to the process column ICCOL2
460*
461 IF( mycol.EQ.ivcol ) THEN
462*
463 ipw = mpv+1
464 CALL zcopy( mpv, v( ioffv ), 1, work, 1 )
465 work( ipw ) = tau( jjv )
466 CALL zgesd2d( ictxt, ipw, 1, work, ipw, myrow,
467 $ iccol2 )
468*
469 ELSE IF( mycol.EQ.iccol2 ) THEN
470*
471 ipw = mpv+1
472 CALL zgerv2d( ictxt, ipw, 1, work, ipw, myrow,
473 $ ivcol )
474 tauloc( 1 ) = work( ipw )
475*
476 IF( tauloc( 1 ).NE.zero ) THEN
477*
478* w := sub( C )' * v
479*
480 IF( mpv.GT.0 ) THEN
481 CALL zgemv( 'Conjugate transpose', mpv, nqc2,
482 $ one, c( ioffc2 ), ldc, work, 1,
483 $ zero, work( ipw ), 1 )
484 ELSE
485 CALL zlaset( 'All', nqc2, 1, zero, zero,
486 $ work( ipw ), max( 1, nqc2 ) )
487 END IF
488 IF( myrow.EQ.icrow1 )
489 $ CALL zaxpy( nqc2, one, c( ioffc1 ), ldc,
490 $ work( ipw ), max( 1, nqc2 ) )
491*
492 CALL zgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
493 $ work( ipw ), max( 1, nqc2 ),
494 $ rdest, mycol )
495*
496* sub( C ) := sub( C ) - v * w'
497*
498 IF( myrow.EQ.icrow1 )
499 $ CALL zaxpy( nqc2, -tauloc( 1 ), work( ipw ),
500 $ max( 1, nqc2 ), c( ioffc1 ),
501 $ ldc )
502 CALL zgerc( mpv, nqc2, -tauloc( 1 ), work, 1,
503 $ work( ipw ), 1, c( ioffc2 ), ldc )
504 END IF
505*
506 END IF
507*
508 END IF
509*
510 END IF
511*
512 ELSE
513*
514* sub( C ) is a proper distributed matrix
515*
516 IF( descv( m_ ).EQ.incv ) THEN
517*
518* Transpose and broadcast row vector V (ICOFFV=IROFFC2)
519*
520 ipw = mpv+1
521 CALL pbztrnv( ictxt, 'Rowwise', 'Transpose', m,
522 $ descv( nb_ ), iroffc2, v( ioffv ), ldv,
523 $ zero,
524 $ work, 1, ivrow, ivcol, icrow2, -1,
525 $ work( ipw ) )
526*
527* Perform the local computation within a process column
528*
529 IF( myrow.EQ.ivrow ) THEN
530*
531 CALL zgebs2d( ictxt, 'Columnwise', ' ', 1, 1,
532 $ tau( iiv ), 1 )
533 tauloc( 1 ) = tau( iiv )
534*
535 ELSE
536*
537 CALL zgebr2d( ictxt, 'Columnwise', ' ', 1, 1, tauloc,
538 $ 1, ivrow, mycol )
539*
540 END IF
541*
542 IF( tauloc( 1 ).NE.zero ) THEN
543*
544* w := sub( C )' * v
545*
546 IF( mpv.GT.0 ) THEN
547 CALL zgemv( 'Conjugate transpose', mpv, nqc2, one,
548 $ c( ioffc2 ), ldc, work, 1, zero,
549 $ work( ipw ), 1 )
550 ELSE
551 CALL zlaset( 'All', nqc2, 1, zero, zero,
552 $ work( ipw ), max( 1, nqc2 ) )
553 END IF
554 IF( myrow.EQ.icrow1 )
555 $ CALL zaxpy( nqc2, one, c( ioffc1 ), ldc,
556 $ work( ipw ), max( 1, nqc2 ) )
557*
558 CALL zgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
559 $ work( ipw ), max( 1, nqc2 ), rdest,
560 $ mycol )
561*
562* sub( C ) := sub( C ) - v * w'
563*
564 IF( myrow.EQ.icrow1 )
565 $ CALL zaxpy( nqc2, -tauloc( 1 ), work( ipw ),
566 $ max( 1, nqc2 ), c( ioffc1 ), ldc )
567 CALL zgerc( mpv, nqc2, -tauloc( 1 ), work, 1,
568 $ work( ipw ), 1, c( ioffc2 ), ldc )
569 END IF
570*
571 ELSE
572*
573* Broadcast column vector V
574*
575 CALL pb_topget( ictxt, 'Broadcast', 'Rowwise', rowbtop )
576 IF( mycol.EQ.ivcol ) THEN
577*
578 ipw = mpv+1
579 CALL zcopy( mpv, v( ioffv ), 1, work, 1 )
580 work( ipw ) = tau( jjv )
581 CALL zgebs2d( ictxt, 'Rowwise', rowbtop, ipw, 1,
582 $ work, ipw )
583 tauloc( 1 ) = tau( jjv )
584*
585 ELSE
586*
587 ipw = mpv+1
588 CALL zgebr2d( ictxt, 'Rowwise', rowbtop, ipw, 1, work,
589 $ ipw, myrow, ivcol )
590 tauloc( 1 ) = work( ipw )
591*
592 END IF
593*
594 IF( tauloc( 1 ).NE.zero ) THEN
595*
596* w := sub( C )' * v
597*
598 IF( mpv.GT.0 ) THEN
599 CALL zgemv( 'Conjugate transpose', mpv, nqc2, one,
600 $ c( ioffc2 ), ldc, work, 1, zero,
601 $ work( ipw ), 1 )
602 ELSE
603 CALL zlaset( 'All', nqc2, 1, zero, zero,
604 $ work( ipw ), max( 1, nqc2 ) )
605 END IF
606 IF( myrow.EQ.icrow1 )
607 $ CALL zaxpy( nqc2, one, c( ioffc1 ), ldc,
608 $ work( ipw ), max( 1, nqc2 ) )
609*
610 CALL zgsum2d( ictxt, 'Columnwise', ' ', nqc2, 1,
611 $ work( ipw ), max( 1, nqc2 ), rdest,
612 $ mycol )
613*
614* sub( C ) := sub( C ) - v * w'
615*
616 IF( myrow.EQ.icrow1 )
617 $ CALL zaxpy( nqc2, -tauloc( 1 ), work( ipw ),
618 $ max( 1, nqc2 ), c( ioffc1 ), ldc )
619 CALL zgerc( mpv, nqc2, -tauloc( 1 ), work, 1,
620 $ work( ipw ), 1, c( ioffc2 ), ldc )
621 END IF
622*
623 END IF
624*
625 END IF
626*
627 ELSE
628*
629 IF( ccblck ) THEN
630 rdest = myrow
631 ELSE
632 rdest = -1
633 END IF
634*
635 IF( crblck ) THEN
636*
637* sub( C ) is distributed over a process row
638*
639 IF( descv( m_ ).EQ.incv ) THEN
640*
641* V is a row vector
642*
643 IF( ivrow.EQ.icrow2 ) THEN
644*
645* Perform the local computation within a process row
646*
647 IF( myrow.EQ.icrow2 ) THEN
648*
649 tauloc( 1 ) = tau( iiv )
650*
651 IF( tauloc( 1 ).NE.zero ) THEN
652*
653* w := sub( C ) * v
654*
655 IF( nqv.GT.0 ) THEN
656 CALL zgemv( 'No transpose', mpc2, nqv, one,
657 $ c( ioffc2 ), ldc, v( ioffv ),
658 $ ldv, zero, work, 1 )
659 ELSE
660 CALL zlaset( 'All', mpc2, 1, zero, zero,
661 $ work, max( 1, mpc2 ) )
662 END IF
663 IF( mycol.EQ.iccol1 )
664 $ CALL zaxpy( mpc2, one, c( ioffc1 ), 1,
665 $ work, 1 )
666*
667 CALL zgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
668 $ work, max( 1, mpc2 ), rdest,
669 $ iccol2 )
670*
671 IF( mycol.EQ.iccol1 )
672 $ CALL zaxpy( mpc2, -tauloc( 1 ), work, 1,
673 $ c( ioffc1 ), 1 )
674*
675* sub( C ) := sub( C ) - w * v'
676*
677 IF( mpc2.GT.0 .AND. nqv.GT.0 )
678 $ CALL zgerc( mpc2, nqv, -tauloc( 1 ), work, 1,
679 $ v( ioffv ), ldv, c( ioffc2 ),
680 $ 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 zcopy( nqv, v( ioffv ), ldv, work, 1 )
693 work( ipw ) = tau( iiv )
694 CALL zgesd2d( ictxt, ipw, 1, work, ipw, icrow2,
695 $ mycol )
696*
697 ELSE IF( myrow.EQ.icrow2 ) THEN
698*
699 ipw = nqv+1
700 CALL zgerv2d( ictxt, ipw, 1, work, ipw, ivrow,
701 $ mycol )
702 tauloc( 1 ) = 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 zgemv( 'No transpose', mpc2, nqv, one,
710 $ c( ioffc2 ), ldc, work, 1, zero,
711 $ work( ipw ), 1 )
712 ELSE
713 CALL zlaset( 'All', mpc2, 1, zero, zero,
714 $ work( ipw ), max( 1, mpc2 ) )
715 END IF
716 IF( mycol.EQ.iccol1 )
717 $ CALL zaxpy( mpc2, one, c( ioffc1 ), 1,
718 $ work( ipw ), 1 )
719 CALL zgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
720 $ work( ipw ), max( 1, mpc2 ),
721 $ rdest, iccol2 )
722 IF( mycol.EQ.iccol1 )
723 $ CALL zaxpy( mpc2, -tauloc( 1 ), work( ipw ),
724 $ 1, c( ioffc1 ), 1 )
725*
726* sub( C ) := sub( C ) - w * v'
727*
728 CALL zgerc( 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 pbztrnv( 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 zgebs2d( ictxt, 'Rowwise', ' ', 1, 1,
754 $ tau( jjv ), 1 )
755 tauloc( 1 ) = tau( jjv )
756*
757 ELSE
758*
759 CALL zgebr2d( ictxt, 'Rowwise', ' ', 1, 1, tauloc,
760 $ 1, myrow, ivcol )
761*
762 END IF
763*
764 IF( tauloc( 1 ).NE.zero ) THEN
765*
766* w := sub( C ) * v
767*
768 IF( nqv.GT.0 ) THEN
769 CALL zgemv( 'No transpose', mpc2, nqv, one,
770 $ c( ioffc2 ), ldc, work, 1, zero,
771 $ work( ipw ), 1 )
772 ELSE
773 CALL zlaset( 'All', mpc2, 1, zero, zero,
774 $ work( ipw ), max( 1, mpc2 ) )
775 END IF
776 IF( mycol.EQ.iccol1 )
777 $ CALL zaxpy( mpc2, one, c( ioffc1 ), 1,
778 $ work( ipw ), 1 )
779 CALL zgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
780 $ work( ipw ), max( 1, mpc2 ), rdest,
781 $ iccol2 )
782 IF( mycol.EQ.iccol1 )
783 $ CALL zaxpy( mpc2, -tauloc( 1 ), work( ipw ), 1,
784 $ c( ioffc1 ), 1 )
785*
786* sub( C ) := sub( C ) - w * v'
787*
788 CALL zgerc( mpc2, nqv, -tauloc( 1 ), work( ipw ),
789 $ 1, work, 1, c( ioffc2 ), ldc )
790 END IF
791*
792 END IF
793*
794 END IF
795*
796 ELSE
797*
798* sub( C ) is a proper distributed matrix
799*
800 IF( descv( m_ ).EQ.incv ) THEN
801*
802* Broadcast row vector V
803*
804 CALL pb_topget( ictxt, 'Broadcast', 'Columnwise',
805 $ colbtop )
806 IF( myrow.EQ.ivrow ) THEN
807*
808 ipw = nqv+1
809 CALL zcopy( nqv, v( ioffv ), ldv, work, 1 )
810 work( ipw ) = tau( iiv )
811 CALL zgebs2d( ictxt, 'Columnwise', colbtop, ipw, 1,
812 $ work, ipw )
813 tauloc( 1 ) = tau( iiv )
814*
815 ELSE
816*
817 ipw = nqv+1
818 CALL zgebr2d( ictxt, 'Columnwise', colbtop, ipw, 1,
819 $ work, ipw, ivrow, mycol )
820 tauloc( 1 ) = work( ipw )
821*
822 END IF
823*
824 IF( tauloc( 1 ).NE.zero ) THEN
825*
826* w := sub( C ) * v
827*
828 IF( nqv.GT.0 ) THEN
829 CALL zgemv( 'No Transpose', mpc2, nqv, one,
830 $ c( ioffc2 ), ldc, work, 1, zero,
831 $ work( ipw ), 1 )
832 ELSE
833 CALL zlaset( 'All', mpc2, 1, zero, zero,
834 $ work( ipw ), max( 1, mpc2 ) )
835 END IF
836 IF( mycol.EQ.iccol1 )
837 $ CALL zaxpy( mpc2, one, c( ioffc1 ), 1,
838 $ work( ipw ), 1 )
839*
840 CALL zgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
841 $ work( ipw ), max( 1, mpc2 ), rdest,
842 $ iccol2 )
843 IF( mycol.EQ.iccol1 )
844 $ CALL zaxpy( mpc2, -tauloc( 1 ), work( ipw ), 1,
845 $ c( ioffc1 ), 1 )
846*
847* sub( C ) := sub( C ) - w * v'
848*
849 CALL zgerc( mpc2, nqv, -tauloc( 1 ), work( ipw ), 1,
850 $ work, 1, c( ioffc2 ), ldc )
851 END IF
852*
853 ELSE
854*
855* Transpose and broadcast column vector V (ICOFFC2=IROFFV)
856*
857 ipw = nqv+1
858 CALL pbztrnv( ictxt, 'Columnwise', 'Transpose', n,
859 $ descv( mb_ ), icoffc2, v( ioffv ), 1, zero,
860 $ work, 1, ivrow, ivcol, -1, iccol2,
861 $ work( ipw ) )
862*
863* Perform the local computation within a process column
864*
865 IF( mycol.EQ.ivcol ) THEN
866*
867 CALL zgebs2d( ictxt, 'Rowwise', ' ', 1, 1, tau( jjv ),
868 $ 1 )
869 tauloc( 1 ) = tau( jjv )
870*
871 ELSE
872*
873 CALL zgebr2d( ictxt, 'Rowwise', ' ', 1, 1, tauloc, 1,
874 $ myrow, ivcol )
875*
876 END IF
877*
878 IF( tauloc( 1 ).NE.zero ) THEN
879*
880* w := sub( C ) * v
881*
882 IF( nqv.GT.0 ) THEN
883 CALL zgemv( 'No transpose', mpc2, nqv, one,
884 $ c( ioffc2 ), ldc, work, 1, zero,
885 $ work( ipw ), 1 )
886 ELSE
887 CALL zlaset( 'All', mpc2, 1, zero, zero,
888 $ work( ipw ), max( 1, mpc2 ) )
889 END IF
890 IF( mycol.EQ.iccol1 )
891 $ CALL zaxpy( mpc2, one, c( ioffc1 ), 1,
892 $ work( ipw ), 1 )
893 CALL zgsum2d( ictxt, 'Rowwise', ' ', mpc2, 1,
894 $ work( ipw ), max( 1, mpc2 ), rdest,
895 $ iccol2 )
896 IF( mycol.EQ.iccol1 )
897 $ CALL zaxpy( mpc2, -tauloc( 1 ), work( ipw ), 1,
898 $ c( ioffc1 ), 1 )
899*
900* sub( C ) := sub( C ) - w * v'
901*
902 CALL zgerc( mpc2, nqv, -tauloc( 1 ), work( ipw ), 1,
903 $ work, 1, c( ioffc2 ), ldc )
904 END IF
905*
906 END IF
907*
908 END IF
909*
910 END IF
911*
912 RETURN
913*
914* End of PZLARZ
915*
916 END
infog2l
subroutine infog2l(grindx, gcindx, desc, nprow, npcol, myrow, mycol, lrindx, lcindx, rsrc, csrc)
Definition infog2l.f:3
pbztrnv
subroutine pbztrnv(icontxt, xdist, trans, n, nb, nz, x, incx, beta, y, incy, ixrow, ixcol, iyrow, iycol, work)
Definition pbztrnv.f:4
max
#define max(A, B)
Definition pcgemr.c:180
min
#define min(A, B)
Definition pcgemr.c:181
pzlarz
subroutine pzlarz(side, m, n, l, v, iv, jv, descv, incv, tau, c, ic, jc, descc, work)
Definition pzlarz.f:3