elpa2.F90 21.5 KB
Newer Older
1
2
3
4
5
!    This file is part of ELPA.
!
!    The ELPA library was originally created by the ELPA consortium,
!    consisting of the following organizations:
!
6
7
!    - Max Planck Computing and Data Facility (MPCDF), fomerly known as
!      Rechenzentrum Garching der Max-Planck-Gesellschaft (RZG),
8
9
10
11
12
13
14
15
16
17
!    - Bergische Universität Wuppertal, Lehrstuhl für angewandte
!      Informatik,
!    - Technische Universität München, Lehrstuhl für Informatik mit
!      Schwerpunkt Wissenschaftliches Rechnen ,
!    - Fritz-Haber-Institut, Berlin, Abt. Theorie,
!    - Max-Plack-Institut für Mathematik in den Naturwissenschaftrn,
!      Leipzig, Abt. Komplexe Strukutren in Biologie und Kognition,
!      and
!    - IBM Deutschland GmbH
!
18
!    This particular source code file contains additions, changes and
Andreas Marek's avatar
Andreas Marek committed
19
!    enhancements authored by Intel Corporation which is not part of
20
!    the ELPA consortium.
21
22
!
!    More information can be found here:
23
!    http://elpa.mpcdf.mpg.de/
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
!
!    ELPA is free software: you can redistribute it and/or modify
!    it under the terms of the version 3 of the license of the
!    GNU Lesser General Public License as published by the Free
!    Software Foundation.
!
!    ELPA is distributed in the hope that it will be useful,
!    but WITHOUT ANY WARRANTY; without even the implied warranty of
!    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
!    GNU Lesser General Public License for more details.
!
!    You should have received a copy of the GNU Lesser General Public License
!    along with ELPA.  If not, see <http://www.gnu.org/licenses/>
!
!    ELPA reflects a substantial effort on the part of the original
!    ELPA consortium, and we ask you to respect the spirit of the
!    license that we chose: i.e., please contribute any changes you
!    may have back to the original ELPA library distribution, and keep
!    any derivatives of ELPA under the same license that we chose for
!    the original distribution, the GNU Lesser General Public License.
!
!
! ELPA1 -- Faster replacements for ScaLAPACK symmetric eigenvalue routines
!
! Copyright of the original code rests with the authors inside the ELPA
! consortium. The copyright of any additional modifications shall rest
! with their original authors, but shall adhere to the licensing terms
! distributed along with the original code in the file "COPYING".



! ELPA2 -- 2-stage solver for ELPA
!
! Copyright of the original code rests with the authors inside the ELPA
! consortium. The copyright of any additional modifications shall rest
! with their original authors, but shall adhere to the licensing terms
! distributed along with the original code in the file "COPYING".


#include "config-f90.h"
64
!> \brief Fortran module which provides the routines to use the two-stage ELPA solver
65
66
67
68
module ELPA2

! Version 1.1.2, 2011-02-21

69
  use elpa_utilities
70
  use elpa1_compute
71
  use elpa1, only : elpa_print_times, time_evp_back, time_evp_fwd, time_evp_solve
72
  use elpa2_utilities
73
  use elpa2_compute
74
75
  use elpa_pdgeqrf

76
  use elpa_mpi
77
78
79
80
81
82
83
84
85
86
87
88
  implicit none

  PRIVATE ! By default, all routines contained are private

  ! The following routines are public:

  public :: solve_evp_real_2stage
  public :: solve_evp_complex_2stage


!******
contains
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
!-------------------------------------------------------------------------------
!>  \brief solve_evp_real_2stage: Fortran function to solve the real eigenvalue problem with a 2 stage approach
!>
!>  Parameters
!>
!>  \param na                                   Order of matrix a
!>
!>  \param nev                                  Number of eigenvalues needed
!>
!>  \param a(lda,matrixCols)                    Distributed matrix for which eigenvalues are to be computed.
!>                                              Distribution is like in Scalapack.
!>                                              The full matrix must be set (not only one half like in scalapack).
!>                                              Destroyed on exit (upper and lower half).
!>
!>  \param lda                                  Leading dimension of a
!>
!>  \param ev(na)                               On output: eigenvalues of a, every processor gets the complete set
!>
!>  \param q(ldq,matrixCols)                    On output: Eigenvectors of a
!>                                              Distribution is like in Scalapack.
!>                                              Must be always dimensioned to the full size (corresponding to (na,na))
!>                                              even if only a part of the eigenvalues is needed.
!>
!>  \param ldq                                  Leading dimension of q
!>
!>  \param nblk                                 blocksize of cyclic distribution, must be the same in both directions!
!>
!>  \param matrixCols                           local columns of matrix a and q
!>
!>  \param mpi_comm_rows                        MPI communicator for rows
!>  \param mpi_comm_cols                        MPI communicator for columns
!>  \param mpi_comm_all                         MPI communicator for the total processor set
!>
!>  \param THIS_REAL_ELPA_KERNEL_API (optional) specify used ELPA2 kernel via API
!>
!>  \param use_qr (optional)                    use QR decomposition
!>
!>  \result success                             logical, false if error occured
!-------------------------------------------------------------------------------
128

129
function solve_evp_real_2stage(na, nev, a, lda, ev, q, ldq, nblk,        &
130
                               matrixCols,                               &
131
132
133
                                 mpi_comm_rows, mpi_comm_cols,           &
                                 mpi_comm_all, THIS_REAL_ELPA_KERNEL_API,&
                                 useQR) result(success)
134

135
#ifdef HAVE_DETAILED_TIMINGS
Andreas Marek's avatar
Andreas Marek committed
136
   use timings
137
#endif
Andreas Marek's avatar
Andreas Marek committed
138
   use precision
139
   implicit none
Andreas Marek's avatar
Andreas Marek committed
140
141
142
143
144
145
146
147
148
   logical, intent(in), optional          :: useQR
   logical                                :: useQRActual, useQREnvironment
   integer(kind=ik), intent(in), optional :: THIS_REAL_ELPA_KERNEL_API
   integer(kind=ik)                       :: THIS_REAL_ELPA_KERNEL

   integer(kind=ik), intent(in)           :: na, nev, lda, ldq, matrixCols, mpi_comm_rows, &
                                             mpi_comm_cols, mpi_comm_all
   integer(kind=ik), intent(in)           :: nblk
   real(kind=rk), intent(inout)           :: a(lda,matrixCols), ev(na), q(ldq,matrixCols)
149
150
   ! was
   ! real a(lda,*), q(ldq,*)
Andreas Marek's avatar
Andreas Marek committed
151
152
153
154
155
156
157
158
159
160
   real(kind=rk), allocatable             :: hh_trans_real(:,:)

   integer(kind=ik)                       :: my_pe, n_pes, my_prow, my_pcol, np_rows, np_cols, mpierr
   integer(kind=ik)                       :: nbw, num_blocks
   real(kind=rk), allocatable             :: tmat(:,:,:), e(:)
   real(kind=rk)                          :: ttt0, ttt1, ttts
   integer(kind=ik)                       :: i
   logical                                :: success
   logical, save                          :: firstCall = .true.
   logical                                :: wantDebug
161

162
163
164
#ifdef HAVE_DETAILED_TIMINGS
   call timer%start("solve_evp_real_2stage")
#endif
165
166
167
168
169
170
171
   call mpi_comm_rank(mpi_comm_all,my_pe,mpierr)
   call mpi_comm_size(mpi_comm_all,n_pes,mpierr)

   call mpi_comm_rank(mpi_comm_rows,my_prow,mpierr)
   call mpi_comm_size(mpi_comm_rows,np_rows,mpierr)
   call mpi_comm_rank(mpi_comm_cols,my_pcol,mpierr)
   call mpi_comm_size(mpi_comm_cols,np_cols,mpierr)
172

173
174
175
176
177
178
179
   wantDebug = .false.
   if (firstCall) then
     ! are debug messages desired?
     wantDebug = debug_messages_via_environment_variable()
     firstCall = .false.
   endif

180
181
   success = .true.

182
183
184
185
186
187
188
189
190
191
192
193
194
   useQRActual = .false.

   ! set usage of qr decomposition via API call
   if (present(useQR)) then
     if (useQR) useQRActual = .true.
     if (.not.(useQR)) useQRACtual = .false.
   endif

   ! overwrite this with environment variable settings
   if (qr_decomposition_via_environment_variable(useQREnvironment)) then
     useQRActual = useQREnvironment
   endif

195
   if (useQRActual) then
196
     if (mod(na,2) .ne. 0) then
197
198
199
       if (wantDebug) then
         write(error_unit,*) "solve_evp_real_2stage: QR-decomposition: blocksize does not fit with matrixsize"
       endif
Andreas Marek's avatar
Andreas Marek committed
200
     print *, "Do not use QR-decomposition for this matrix and blocksize."
Andreas Marek's avatar
Andreas Marek committed
201
202
     success = .false.
     return
203
     endif
204
205
   endif

206

207
208
209
   if (present(THIS_REAL_ELPA_KERNEL_API)) then
     ! user defined kernel via the optional argument in the API call
     THIS_REAL_ELPA_KERNEL = THIS_REAL_ELPA_KERNEL_API
Andreas Marek's avatar
Andreas Marek committed
210
   else
211

212
213
214
     ! if kernel is not choosen via api
     ! check whether set by environment variable
     THIS_REAL_ELPA_KERNEL = get_actual_real_kernel()
Andreas Marek's avatar
Andreas Marek committed
215
216
   endif

217
   ! check whether choosen kernel is allowed: function returns true if NOT allowed! change this
Andreas Marek's avatar
Andreas Marek committed
218
   if (check_allowed_real_kernels(THIS_REAL_ELPA_KERNEL)) then
219

220
221
222
223
224
225
226
227
228
229
230
     if (my_pe == 0) then
       write(error_unit,*) " "
       write(error_unit,*) "The choosen kernel ",REAL_ELPA_KERNEL_NAMES(THIS_REAL_ELPA_KERNEL)
       write(error_unit,*) "is not in the list of the allowed kernels!"
       write(error_unit,*) " "
       write(error_unit,*) "Allowed kernels are:"
       do i=1,size(REAL_ELPA_KERNEL_NAMES(:))
         if (AVAILABLE_REAL_ELPA_KERNELS(i) .ne. 0) then
           write(error_unit,*) REAL_ELPA_KERNEL_NAMES(i)
         endif
       enddo
Andreas Marek's avatar
Andreas Marek committed
231

232
       write(error_unit,*) " "
233
234
235
236
237
238
239
240
241
242
243
       ! check whether generic kernel is defined
       if (AVAILABLE_REAL_ELPA_KERNELS(REAL_ELPA_KERNEL_GENERIC) .eq. 1) then
         write(error_unit,*) "The default kernel REAL_ELPA_KERNEL_GENERIC will be used !"
       else
         write(error_unit,*) "As default kernel ",REAL_ELPA_KERNEL_NAMES(DEFAULT_REAL_ELPA_KERNEL)," will be used"
       endif
     endif  ! my_pe == 0
     if (AVAILABLE_REAL_ELPA_KERNELS(REAL_ELPA_KERNEL_GENERIC) .eq. 1) then
       THIS_REAL_ELPA_KERNEL = REAL_ELPA_KERNEL_GENERIC
     else
       THIS_REAL_ELPA_KERNEL = DEFAULT_REAL_ELPA_KERNEL
244
     endif
Andreas Marek's avatar
Andreas Marek committed
245
   endif
246
247

   ! Choose bandwidth, must be a multiple of nblk, set to a value >= 32
Andreas Marek's avatar
Andreas Marek committed
248
   ! On older systems (IBM Bluegene/P, Intel Nehalem) a value of 32 was optimal.
249
   ! For Intel(R) Xeon(R) E5 v2 and v3, better use 64 instead of 32!
Andreas Marek's avatar
Andreas Marek committed
250
251
   ! For IBM Bluegene/Q this is not clear at the moment. We have to keep an eye
   ! on this and maybe allow a run-time optimization here
252
   nbw = (63/nblk+1)*nblk
253
254
255
256
257
258
259
260
261

   num_blocks = (na-1)/nbw + 1

   allocate(tmat(nbw,nbw,num_blocks))

   ! Reduction full -> band

   ttt0 = MPI_Wtime()
   ttts = ttt0
262
   call bandred_real(na, a, lda, nblk, nbw, matrixCols, num_blocks, mpi_comm_rows, mpi_comm_cols, &
263
                     tmat, wantDebug, success, useQRActual)
264
   if (.not.(success)) return
265
   ttt1 = MPI_Wtime()
266
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
267
      write(error_unit,*) 'Time bandred_real               :',ttt1-ttt0
268
269
270
271
272
273

   ! Reduction band -> tridiagonal

   allocate(e(na))

   ttt0 = MPI_Wtime()
274
275
   call tridiag_band_real(na, nbw, nblk, a, lda, ev, e, matrixCols, hh_trans_real, &
                          mpi_comm_rows, mpi_comm_cols, mpi_comm_all)
276
   ttt1 = MPI_Wtime()
277
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
278
      write(error_unit,*) 'Time tridiag_band_real          :',ttt1-ttt0
279
#ifdef WITH_MPI
280
281
   call mpi_bcast(ev,na,MPI_REAL8,0,mpi_comm_all,mpierr)
   call mpi_bcast(e,na,MPI_REAL8,0,mpi_comm_all,mpierr)
282
#endif
283
284
285
286
287
288
   ttt1 = MPI_Wtime()
   time_evp_fwd = ttt1-ttts

   ! Solve tridiagonal system

   ttt0 = MPI_Wtime()
289
   call solve_tridi(na, nev, ev, e, q, ldq, nblk, matrixCols, mpi_comm_rows,  &
290
                    mpi_comm_cols, wantDebug, success)
291
292
   if (.not.(success)) return

293
   ttt1 = MPI_Wtime()
294
295
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
     write(error_unit,*) 'Time solve_tridi                :',ttt1-ttt0
296
297
298
299
300
301
302
303
   time_evp_solve = ttt1-ttt0
   ttts = ttt1

   deallocate(e)

   ! Backtransform stage 1

   ttt0 = MPI_Wtime()
304
305
306
   call trans_ev_tridi_to_band_real(na, nev, nblk, nbw, q, ldq, matrixCols, hh_trans_real, &
                                    mpi_comm_rows, mpi_comm_cols, wantDebug, success,      &
                                    THIS_REAL_ELPA_KERNEL)
307
   if (.not.(success)) return
308
   ttt1 = MPI_Wtime()
309
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
310
      write(error_unit,*) 'Time trans_ev_tridi_to_band_real:',ttt1-ttt0
311
312
313
314
315
316
317

   ! We can now deallocate the stored householder vectors
   deallocate(hh_trans_real)

   ! Backtransform stage 2

   ttt0 = MPI_Wtime()
318
   call trans_ev_band_to_full_real(na, nev, nblk, nbw, a, lda, tmat, q, ldq, matrixCols, num_blocks, mpi_comm_rows, &
319
                                   mpi_comm_cols, useQRActual)
320
   ttt1 = MPI_Wtime()
321
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
322
      write(error_unit,*) 'Time trans_ev_band_to_full_real :',ttt1-ttt0
323
324
325
   time_evp_back = ttt1-ttts

   deallocate(tmat)
326
327
328
#ifdef HAVE_DETAILED_TIMINGS
   call timer%stop("solve_evp_real_2stage")
#endif
329
330
1  format(a,f10.3)

331
end function solve_evp_real_2stage
332
333
334


!-------------------------------------------------------------------------------
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
!>  \brief solve_evp_complex_2stage: Fortran function to solve the complex eigenvalue problem with a 2 stage approach
!>
!>  Parameters
!>
!>  \param na                                   Order of matrix a
!>
!>  \param nev                                  Number of eigenvalues needed
!>
!>  \param a(lda,matrixCols)                    Distributed matrix for which eigenvalues are to be computed.
!>                                              Distribution is like in Scalapack.
!>                                              The full matrix must be set (not only one half like in scalapack).
!>                                              Destroyed on exit (upper and lower half).
!>
!>  \param lda                                  Leading dimension of a
!>
!>  \param ev(na)                               On output: eigenvalues of a, every processor gets the complete set
!>
!>  \param q(ldq,matrixCols)                    On output: Eigenvectors of a
!>                                              Distribution is like in Scalapack.
!>                                              Must be always dimensioned to the full size (corresponding to (na,na))
!>                                              even if only a part of the eigenvalues is needed.
!>
!>  \param ldq                                  Leading dimension of q
!>
!>  \param nblk                                 blocksize of cyclic distribution, must be the same in both directions!
!>
!>  \param matrixCols                           local columns of matrix a and q
!>
!>  \param mpi_comm_rows                        MPI communicator for rows
!>  \param mpi_comm_cols                        MPI communicator for columns
!>  \param mpi_comm_all                         MPI communicator for the total processor set
!>
!>  \param THIS_REAL_ELPA_KERNEL_API (optional) specify used ELPA2 kernel via API
!>
!>  \result success                             logical, false if error occured
!-------------------------------------------------------------------------------
371
function solve_evp_complex_2stage(na, nev, a, lda, ev, q, ldq, nblk, &
372
                                  matrixCols, mpi_comm_rows, mpi_comm_cols,      &
373
                                    mpi_comm_all, THIS_COMPLEX_ELPA_KERNEL_API) result(success)
374

375
#ifdef HAVE_DETAILED_TIMINGS
Andreas Marek's avatar
Andreas Marek committed
376
   use timings
377
#endif
Andreas Marek's avatar
Andreas Marek committed
378
   use precision
379
   implicit none
Andreas Marek's avatar
Andreas Marek committed
380
381
382
383
   integer(kind=ik), intent(in), optional :: THIS_COMPLEX_ELPA_KERNEL_API
   integer(kind=ik)                       :: THIS_COMPLEX_ELPA_KERNEL
   integer(kind=ik), intent(in)           :: na, nev, lda, ldq, nblk, matrixCols, mpi_comm_rows, mpi_comm_cols, mpi_comm_all
   complex(kind=ck), intent(inout)        :: a(lda,matrixCols), q(ldq,matrixCols)
384
385
   ! was
   ! complex a(lda,*), q(ldq,*)
Andreas Marek's avatar
Andreas Marek committed
386
387
388
389
390
391
392
393
394
395
396
397
   real(kind=rk), intent(inout)           :: ev(na)
   complex(kind=ck), allocatable          :: hh_trans_complex(:,:)

   integer(kind=ik)                       :: my_prow, my_pcol, np_rows, np_cols, mpierr, my_pe, n_pes
   integer(kind=ik)                       :: l_cols, l_rows, l_cols_nev, nbw, num_blocks
   complex(kind=ck), allocatable          :: tmat(:,:,:)
   real(kind=rk), allocatable             :: q_real(:,:), e(:)
   real(kind=rk)                          :: ttt0, ttt1, ttts
   integer(kind=ik)                       :: i

   logical                                :: success, wantDebug
   logical, save                          :: firstCall = .true.
398

399
400
401
#ifdef HAVE_DETAILED_TIMINGS
   call timer%start("solve_evp_complex_2stage")
#endif
Andreas Marek's avatar
Andreas Marek committed
402
403
   call mpi_comm_rank(mpi_comm_all,my_pe,mpierr)
   call mpi_comm_size(mpi_comm_all,n_pes,mpierr)
404
405
406
407
408

   call mpi_comm_rank(mpi_comm_rows,my_prow,mpierr)
   call mpi_comm_size(mpi_comm_rows,np_rows,mpierr)
   call mpi_comm_rank(mpi_comm_cols,my_pcol,mpierr)
   call mpi_comm_size(mpi_comm_cols,np_cols,mpierr)
409
410
411
412
413
414
415
416
   wantDebug = .false.
   if (firstCall) then
     ! are debug messages desired?
     wantDebug = debug_messages_via_environment_variable()
     firstCall = .false.
   endif


417
418
   success = .true.

419
420
421
   if (present(THIS_COMPLEX_ELPA_KERNEL_API)) then
     ! user defined kernel via the optional argument in the API call
     THIS_COMPLEX_ELPA_KERNEL = THIS_COMPLEX_ELPA_KERNEL_API
Andreas Marek's avatar
Andreas Marek committed
422
   else
423
424
425
     ! if kernel is not choosen via api
     ! check whether set by environment variable
     THIS_COMPLEX_ELPA_KERNEL = get_actual_complex_kernel()
Andreas Marek's avatar
Andreas Marek committed
426
   endif
427

Andreas Marek's avatar
Andreas Marek committed
428
429
   ! check whether choosen kernel is allowed
   if (check_allowed_complex_kernels(THIS_COMPLEX_ELPA_KERNEL)) then
430

431
432
433
434
435
436
437
438
439
440
441
     if (my_pe == 0) then
       write(error_unit,*) " "
       write(error_unit,*) "The choosen kernel ",COMPLEX_ELPA_KERNEL_NAMES(THIS_COMPLEX_ELPA_KERNEL)
       write(error_unit,*) "is not in the list of the allowed kernels!"
       write(error_unit,*) " "
       write(error_unit,*) "Allowed kernels are:"
       do i=1,size(COMPLEX_ELPA_KERNEL_NAMES(:))
         if (AVAILABLE_COMPLEX_ELPA_KERNELS(i) .ne. 0) then
           write(error_unit,*) COMPLEX_ELPA_KERNEL_NAMES(i)
         endif
       enddo
Andreas Marek's avatar
Andreas Marek committed
442

443
       write(error_unit,*) " "
444
445
446
447
448
449
450
451
452
453
454
       ! check whether generic kernel is defined
       if (AVAILABLE_COMPLEX_ELPA_KERNELS(COMPLEX_ELPA_KERNEL_GENERIC) .eq. 1) then
         write(error_unit,*) "The default kernel COMPLEX_ELPA_KERNEL_GENERIC will be used !"
       else
         write(error_unit,*) "As default kernel ",COMPLEX_ELPA_KERNEL_NAMES(DEFAULT_COMPLEX_ELPA_KERNEL)," will be used"
       endif
     endif  ! my_pe == 0
     if (AVAILABLE_COMPLEX_ELPA_KERNELS(COMPLEX_ELPA_KERNEL_GENERIC) .eq. 1) then
       THIS_COMPLEX_ELPA_KERNEL = COMPLEX_ELPA_KERNEL_GENERIC
     else
       THIS_COMPLEX_ELPA_KERNEL = DEFAULT_COMPLEX_ELPA_KERNEL
455
     endif
Andreas Marek's avatar
Andreas Marek committed
456
   endif
457
458
459
460
461
462
463
464
465
466
467
468
   ! Choose bandwidth, must be a multiple of nblk, set to a value >= 32

   nbw = (31/nblk+1)*nblk

   num_blocks = (na-1)/nbw + 1

   allocate(tmat(nbw,nbw,num_blocks))

   ! Reduction full -> band

   ttt0 = MPI_Wtime()
   ttts = ttt0
469
   call bandred_complex(na, a, lda, nblk, nbw, matrixCols, num_blocks, mpi_comm_rows, mpi_comm_cols, &
470
                        tmat, wantDebug, success)
471
472
473
474
475
476
   if (.not.(success)) then
#ifdef HAVE_DETAILED_TIMINGS
     call timer%stop()
#endif
     return
   endif
477
   ttt1 = MPI_Wtime()
478
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
479
      write(error_unit,*) 'Time bandred_complex               :',ttt1-ttt0
480
481
482
483
484
485

   ! Reduction band -> tridiagonal

   allocate(e(na))

   ttt0 = MPI_Wtime()
486
487
   call tridiag_band_complex(na, nbw, nblk, a, lda, ev, e, matrixCols, hh_trans_complex, &
                             mpi_comm_rows, mpi_comm_cols, mpi_comm_all)
488
   ttt1 = MPI_Wtime()
489
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
490
      write(error_unit,*) 'Time tridiag_band_complex          :',ttt1-ttt0
491
#ifdef WITH_MPI
492
493
   call mpi_bcast(ev,na,MPI_REAL8,0,mpi_comm_all,mpierr)
   call mpi_bcast(e,na,MPI_REAL8,0,mpi_comm_all,mpierr)
494
#endif
495
496
497
498
499
500
501
502
503
504
505
506
   ttt1 = MPI_Wtime()
   time_evp_fwd = ttt1-ttts

   l_rows = local_index(na, my_prow, np_rows, nblk, -1) ! Local rows of a and q
   l_cols = local_index(na, my_pcol, np_cols, nblk, -1) ! Local columns of q
   l_cols_nev = local_index(nev, my_pcol, np_cols, nblk, -1) ! Local columns corresponding to nev

   allocate(q_real(l_rows,l_cols))

   ! Solve tridiagonal system

   ttt0 = MPI_Wtime()
507
   call solve_tridi(na, nev, ev, e, q_real, ubound(q_real,dim=1), nblk, matrixCols, &
508
                    mpi_comm_rows, mpi_comm_cols, wantDebug, success)
509
510
   if (.not.(success)) return

511
   ttt1 = MPI_Wtime()
512
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times)  &
513
      write(error_unit,*) 'Time solve_tridi                   :',ttt1-ttt0
514
515
516
517
518
519
520
521
522
523
   time_evp_solve = ttt1-ttt0
   ttts = ttt1

   q(1:l_rows,1:l_cols_nev) = q_real(1:l_rows,1:l_cols_nev)

   deallocate(e, q_real)

   ! Backtransform stage 1

   ttt0 = MPI_Wtime()
524
525
526
   call trans_ev_tridi_to_band_complex(na, nev, nblk, nbw, q, ldq,   &
                                       matrixCols, hh_trans_complex, &
                                       mpi_comm_rows, mpi_comm_cols, &
527
                                       wantDebug, success,THIS_COMPLEX_ELPA_KERNEL)
528
   if (.not.(success)) return
529
   ttt1 = MPI_Wtime()
530
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
531
      write(error_unit,*) 'Time trans_ev_tridi_to_band_complex:',ttt1-ttt0
532
533
534
535
536
537
538

   ! We can now deallocate the stored householder vectors
   deallocate(hh_trans_complex)

   ! Backtransform stage 2

   ttt0 = MPI_Wtime()
Andreas Marek's avatar
Andreas Marek committed
539
540
   call trans_ev_band_to_full_complex(na, nev, nblk, nbw, a, lda, tmat, q, ldq, matrixCols, num_blocks, &
                                      mpi_comm_rows, mpi_comm_cols)
541
   ttt1 = MPI_Wtime()
542
   if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
543
      write(error_unit,*) 'Time trans_ev_band_to_full_complex :',ttt1-ttt0
544
545
546
   time_evp_back = ttt1-ttts

   deallocate(tmat)
547
548
549
#ifdef HAVE_DETAILED_TIMINGS
   call timer%stop("solve_evp_complex_2stage")
#endif
550
551
552

1  format(a,f10.3)

553
end function solve_evp_complex_2stage
554
555

end module ELPA2