interface for already banded matrix added

Makefile.am

@@ -315,6 +315,7 @@ dist_files_DATA = \
   test/Fortran/test_real2_default.F90 \
   test/Fortran/test_real2_qr.F90 \
   test/Fortran/test_real2_api.F90 \
+  test/Fortran/test_real2_banded.F90 \
   test/Fortran/test_real.F90 \
   test/Fortran/test_real_with_c.F90 \
   test/Fortran/test_toeplitz.F90 \
@@ -345,6 +346,7 @@ noinst_PROGRAMS = \
   elpa2_test_real_default@SUFFIX@ \
   elpa2_test_real_qr@SUFFIX@ \
   elpa2_test_real_api@SUFFIX@ \
+  elpa2_test_real_banded@SUFFIX@ \
   elpa2_test_complex@SUFFIX@ \
   elpa2_test_complex_default@SUFFIX@ \
   elpa2_test_complex_api@SUFFIX@ \
@@ -532,6 +534,11 @@ elpa2_test_real_api@SUFFIX@_LDADD = $(build_lib)
 elpa2_test_real_api@SUFFIX@_FCFLAGS = $(AM_FCFLAGS) @FC_MODOUT@private_modules @FC_MODINC@private_modules
 EXTRA_elpa2_test_real_api@SUFFIX@_DEPENDENCIES = test/Fortran/elpa_print_headers.X90
 
+elpa2_test_real_banded@SUFFIX@_SOURCES = test/Fortran/test_real2_banded.F90
+elpa2_test_real_banded@SUFFIX@_LDADD = $(build_lib)
+elpa2_test_real_banded@SUFFIX@_FCFLAGS = $(AM_FCFLAGS) @FC_MODOUT@private_modules @FC_MODINC@private_modules
+EXTRA_elpa2_test_real_banded@SUFFIX@_DEPENDENCIES = test/Fortran/elpa_print_headers.X90
+
 elpa1_test_complex@SUFFIX@_SOURCES = test/Fortran/test_complex.F90
 elpa1_test_complex@SUFFIX@_LDADD = $(build_lib)
 elpa1_test_complex@SUFFIX@_FCFLAGS = $(AM_FCFLAGS) @FC_MODOUT@private_modules @FC_MODINC@private_modules
@@ -731,6 +738,7 @@ check_SCRIPTS = \
   elpa2_test_real_qr@SUFFIX@.sh \
   elpa2_test_complex_default@SUFFIX@.sh \
   elpa2_test_real_api@SUFFIX@.sh \
+  elpa2_test_real_banded@SUFFIX@.sh \
   elpa2_test_complex_api@SUFFIX@.sh \
   elpa_driver_real@SUFFIX@.sh \
   elpa_driver_complex@SUFFIX@.sh \

src/elpa2_template.X90

 #if REALCASE == 1     
   function solve_evp_real_2stage_PRECISION (na, nev, a, lda, ev, q, ldq, nblk, &
                                  matrixCols, mpi_comm_rows, mpi_comm_cols,   &
-                                 mpi_comm_all, THIS_ELPA_KERNEL_API, useQR, useGPU) result(success)
+                                 mpi_comm_all, THIS_ELPA_KERNEL_API, useQR, useGPU, bandwidth) result(success)
 #elif COMPLEXCASE == 1      
   function solve_evp_complex_2stage_PRECISION(na, nev, a, lda, ev, q, ldq, nblk, &
                                   matrixCols, mpi_comm_rows, mpi_comm_cols,      &
-                                    mpi_comm_all, THIS_ELPA_KERNEL_API, useGPU) result(success)
+                                    mpi_comm_all, THIS_ELPA_KERNEL_API, useGPU, bandwidth) result(success)
 #endif
 #ifdef HAVE_DETAILED_TIMINGS
     use timings
@@ -23,8 +23,11 @@
    logical, intent(in), optional             :: useGPU
 #if REALCASE == 1
    logical, intent(in), optional             :: useQR
-#endif
+#endif   
    logical                                   :: useQRActual, useQREnvironment
+
+   integer(kind=c_int), intent(in), optional :: bandwidth
+
    integer(kind=c_int), intent(in), optional :: THIS_ELPA_KERNEL_API
    integer(kind=c_int)                       :: THIS_ELPA_KERNEL
 
@@ -190,44 +193,61 @@
       endif
     endif
 
-    ! Choose bandwidth, must be a multiple of nblk, set to a value >= 32
-    ! On older systems (IBM Bluegene/P, Intel Nehalem) a value of 32 was optimal.
-    ! For Intel(R) Xeon(R) E5 v2 and v3, better use 64 instead of 32!
-    ! 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
-    if (do_useGPU) then
-      nbw = nblk
+    if(present(bandwidth)) then
+      nbw = bandwidth
+
+      if ((nbw == 0) .or. (mod(nbw, nblk) .ne. 0)) then
+        if (wantDebug) then
+          write(error_unit,*) "Specified bandwidth has to be a multiple of blocksize"
+        endif
+        print *, "Specified bandwidth has to be a multiple of blocksize"
+        success = .false.
+        return
+      endif
+
+      ttts = MPI_Wtime()
     else
+
+      ! Choose bandwidth, must be a multiple of nblk, set to a value >= 32
+      ! On older systems (IBM Bluegene/P, Intel Nehalem) a value of 32 was optimal.
+      ! For Intel(R) Xeon(R) E5 v2 and v3, better use 64 instead of 32!
+      ! 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
+      if (do_useGPU) then
+        nbw = nblk
+      else
 #if REALCASE == 1
-      nbw = (63/nblk+1)*nblk
+        nbw = (63/nblk+1)*nblk
 #elif COMPLEXCASE == 1
-     nbw = (31/nblk+1)*nblk
+        nbw = (31/nblk+1)*nblk
 #endif
-    endif
+      endif
     
-    num_blocks = (na-1)/nbw + 1
+      num_blocks = (na-1)/nbw + 1
 
-    allocate(tmat(nbw,nbw,num_blocks), stat=istat, errmsg=errorMessage)
-    if (istat .ne. 0) then
-      print *,solve_evp_NUMBER_2stage_PRECISION_STR//": error when allocating tmat "//errorMessage
-      stop
-    endif
+      allocate(tmat(nbw,nbw,num_blocks), stat=istat, errmsg=errorMessage)
+      if (istat .ne. 0) then
+        print *,solve_evp_NUMBER_2stage_PRECISION_STR//": error when allocating tmat "//errorMessage
+        stop
+      endif
 
-    ! Reduction full -> band
+      ! Reduction full -> band
 
-    ttt0 = MPI_Wtime()
-    ttts = ttt0
+      ttt0 = MPI_Wtime()
+      ttts = ttt0
 #if REALCASE == 1
-    call bandred_real_PRECISION(na, a, a_dev, lda, nblk, nbw, matrixCols, num_blocks, mpi_comm_rows, mpi_comm_cols, &
-        tmat, tmat_dev, wantDebug, do_useGPU, success, useQRActual)
+      call bandred_real_PRECISION(na, a, a_dev, lda, nblk, nbw, matrixCols, num_blocks, mpi_comm_rows, mpi_comm_cols, &
+          tmat, tmat_dev, wantDebug, do_useGPU, success, useQRActual)
 #elif COMPLEXCASE == 1
-    call bandred_complex_PRECISION(na, a, lda, nblk, nbw, matrixCols, num_blocks, mpi_comm_rows, mpi_comm_cols, &
-        tmat, wantDebug, do_useGPU, success)
+      call bandred_complex_PRECISION(na, a, lda, nblk, nbw, matrixCols, num_blocks, mpi_comm_rows, mpi_comm_cols, &
+          tmat, wantDebug, do_useGPU, success)
 #endif
-    if (.not.(success)) return
-    ttt1 = MPI_Wtime()
-    if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
-       write(error_unit,*) 'Time '//bandred_NUMBER_PRECISION_STR//'               :',ttt1-ttt0
+      if (.not.(success)) return
+      ttt1 = MPI_Wtime()
+      if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
+        write(error_unit,*) 'Time '//bandred_NUMBER_PRECISION_STR//'               :',ttt1-ttt0
+
+    end if  ! matrix not already banded on input
 
      ! Reduction band -> tridiagonal
 
@@ -327,32 +347,36 @@
        stop
      endif
 
-
-     ! Backtransform stage 2
-     ttt0 = MPI_Wtime()
+     if(present(bandwidth)) then 
+       time_evp_back = ttt1-ttts
+     else
+       ! Backtransform stage 2
+       ttt0 = MPI_Wtime()
 #if REALCASE == 1
-     call trans_ev_band_to_full_real_PRECISION(na, nev, nblk, nbw, a, a_dev, lda, tmat, tmat_dev,  &
-                         q, q_dev, ldq, matrixCols, num_blocks, &
-                         mpi_comm_rows, mpi_comm_cols, do_useGPU, useQRActual)
+       call trans_ev_band_to_full_real_PRECISION(na, nev, nblk, nbw, a, a_dev, lda, tmat, tmat_dev,  &
+                           q, q_dev, ldq, matrixCols, num_blocks, &
+                           mpi_comm_rows, mpi_comm_cols, do_useGPU, useQRActual)
 #elif COMPLEXCASE == 1
-     call trans_ev_band_to_full_complex_PRECISION(na, nev, nblk, nbw, a, lda, tmat, &
-                         q, ldq, matrixCols, num_blocks, &
-                         mpi_comm_rows, mpi_comm_cols, do_useGPU)
+       call trans_ev_band_to_full_complex_PRECISION(na, nev, nblk, nbw, a, lda, tmat, &
+                           q, ldq, matrixCols, num_blocks, &
+                           mpi_comm_rows, mpi_comm_cols, do_useGPU)
 
 #endif
 
-     ttt1 = MPI_Wtime()
-     if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
-       write(error_unit,*) 'Time '//trans_ev_band_to_full_NUMBER_PRECISION_STR//' :',ttt1-ttt0
-     time_evp_back = ttt1-ttts
+       ttt1 = MPI_Wtime()
+       if (my_prow==0 .and. my_pcol==0 .and. elpa_print_times) &
+         write(error_unit,*) 'Time '//trans_ev_band_to_full_NUMBER_PRECISION_STR//' :',ttt1-ttt0
 
-     deallocate(tmat, stat=istat, errmsg=errorMessage)
-     if (istat .ne. 0) then
-       print *,solve_evp_NUMBER_2stage_PRECISION_STR//": error when deallocating tmat"//errorMessage
-       stop
-     endif
+       time_evp_back = ttt1-ttts
+
+       deallocate(tmat, stat=istat, errmsg=errorMessage)
+       if (istat .ne. 0) then
+         print *,solve_evp_NUMBER_2stage_PRECISION_STR//": error when deallocating tmat"//errorMessage
+         stop
+       endif
+     endif ! not present(bandwidth)
 
      call timer%stop(solve_evp_NUMBER_2stage_PRECISION_STR)
 1    format(a,f10.3)
-
+    
    end function solve_evp_NUMBER_2stage_PRECISION

test/Fortran/test_real2_banded.F90

+!    This file is part of ELPA.
+!
+!    The ELPA library was originally created by the ELPA consortium,
+!    consisting of the following organizations:
+!
+!    - Max Planck Computing and Data Facility (MPCDF), formerly known as
+!      Rechenzentrum Garching der Max-Planck-Gesellschaft (RZG),
+!    - 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 Naturwissenschaften,
+!      Leipzig, Abt. Komplexe Strukutren in Biologie und Kognition,
+!      and
+!    - IBM Deutschland GmbH
+!
+!
+!    More information can be found here:
+!    http://elpa.mpcdf.mpg.de/
+!
+!    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.
+!
+!
+#include "config-f90.h"
+!>
+!> Fortran test programm to demonstrates the use of
+!> ELPA 2 real case library.
+!> If "HAVE_REDIRECT" was defined at build time
+!> the stdout and stderr output of each MPI task
+!> can be redirected to files if the environment
+!> variable "REDIRECT_ELPA_TEST_OUTPUT" is set
+!> to "true".
+!>
+!> By calling executable [arg1] [arg2] [arg3] [arg4]
+!> one can define the size (arg1), the number of
+!> Eigenvectors to compute (arg2), and the blocking (arg3).
+!> If these values are not set default values (4000, 1500, 16)
+!> are choosen.
+!> If these values are set the 4th argument can be
+!> "output", which specifies that the EV's are written to
+!> an ascii file.
+!>
+!> The real ELPA 2 kernel is set as the default kernel.
+!> However, this can be overriden by setting
+!> the environment variable "REAL_ELPA_KERNEL" to an
+!> appropiate value.
+!>
+program test_real2_double_precision
+
+!-------------------------------------------------------------------------------
+! Standard eigenvalue problem - REAL version
+!
+! This program demonstrates the use of the ELPA module
+! together with standard scalapack 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".
+!
+!-------------------------------------------------------------------------------
+   use precision
+   use ELPA1
+   use ELPA2
+
+   use mod_check_for_gpu, only : check_for_gpu
+   use elpa_utilities, only : error_unit
+#ifdef WITH_OPENMP
+   use test_util
+#endif
+
+   use mod_read_input_parameters
+   use mod_check_correctness
+   use mod_setup_mpi
+   use mod_blacs_infrastructure
+   use mod_prepare_matrix
+   use elpa_mpi
+#ifdef HAVE_REDIRECT
+  use redirect
+#endif
+#ifdef HAVE_DETAILED_TIMINGS
+ use timings
+#endif
+ use output_types
+   implicit none
+
+   !-------------------------------------------------------------------------------
+   ! Please set system size parameters below!
+   ! na:   System size
+   ! nev:  Number of eigenvectors to be calculated
+   ! nblk: Blocking factor in block cyclic distribution
+   !-------------------------------------------------------------------------------
+
+   integer(kind=ik)           :: nblk
+   integer(kind=ik)           :: na, nev
+
+   integer(kind=ik)           :: np_rows, np_cols, na_rows, na_cols
+
+   integer(kind=ik)           :: myid, nprocs, my_prow, my_pcol, mpi_comm_rows, mpi_comm_cols
+   integer(kind=ik)           :: i, mpierr, my_blacs_ctxt, sc_desc(9), info, nprow, npcol
+
+   integer(kind=ik), external :: numroc
+
+   real(kind=rk8), allocatable :: a(:,:), z(:,:), tmp1(:,:), tmp2(:,:), as(:,:), ev(:)
+
+   integer(kind=ik)           :: iseed(4096) ! Random seed, size should be sufficient for every generator
+   integer(kind=ik)           :: STATUS
+#ifdef WITH_OPENMP
+   integer(kind=ik)           :: omp_get_max_threads,  required_mpi_thread_level, provided_mpi_thread_level
+#endif
+   logical                    :: successELPA, success
+   integer(kind=ik)           :: numberOfDevices
+   logical                    :: gpuAvailable
+   type(output_t)             :: write_to_file
+   character(len=8)           :: task_suffix
+   integer(kind=ik)           :: j
+   integer(kind=ik)           :: global_row, global_col, local_row, local_col
+   integer(kind=ik)           :: bandwidth
+
+#define DOUBLE_PRECISION_REAL 1
+
+   successELPA   = .true.
+   gpuAvailable  = .false.
+
+   call read_input_parameters(na, nev, nblk, write_to_file)
+
+   !-------------------------------------------------------------------------------
+   !  MPI Initialization
+   call setup_mpi(myid, nprocs)
+
+   gpuAvailable = check_for_gpu(myid, numberOfDevices)
+
+   STATUS = 0
+
+#define REALCASE
+#include "elpa_print_headers.X90"
+
+#ifdef HAVE_DETAILED_TIMINGS
+
+   ! initialise the timing functionality
+
+#ifdef HAVE_LIBPAPI
+   call timer%measure_flops(.true.)
+#endif
+
+   call timer%measure_allocated_memory(.true.)
+   call timer%measure_virtual_memory(.true.)
+   call timer%measure_max_allocated_memory(.true.)
+
+   call timer%set_print_options(&
+#ifdef HAVE_LIBPAPI
+                print_flop_count=.true., &
+                print_flop_rate=.true., &
+#endif
+                print_allocated_memory = .true. , &
+                print_virtual_memory=.true., &
+                print_max_allocated_memory=.true.)
+
+
+  call timer%enable()
+
+  call timer%start("program: test_real2_double_precision")
+#endif
+
+   !-------------------------------------------------------------------------------
+   ! Selection of number of processor rows/columns
+   ! We try to set up the grid square-like, i.e. start the search for possible
+   ! divisors of nprocs with a number next to the square root of nprocs
+   ! and decrement it until a divisor is found.
+
+   do np_cols = NINT(SQRT(REAL(nprocs))),2,-1
+      if(mod(nprocs,np_cols) == 0 ) exit
+   enddo
+   ! at the end of the above loop, nprocs is always divisible by np_cols
+
+   np_rows = nprocs/np_cols
+
+   if(myid==0) then
+      print *
+      print '(a)','Standard eigenvalue problem - REAL version'
+      print *
+      print '(3(a,i0))','Matrix size=',na,', Number of eigenvectors=',nev,', Block size=',nblk
+      print '(3(a,i0))','Number of processor rows=',np_rows,', cols=',np_cols,', total=',nprocs
+      print *
+   endif
+
+   !-------------------------------------------------------------------------------
+   ! Set up BLACS context and MPI communicators
+   !
+   ! The BLACS context is only necessary for using Scalapack.
+   !
+   ! For ELPA, the MPI communicators along rows/cols are sufficient,
+   ! and the grid setup may be done in an arbitrary way as long as it is
+   ! consistent (i.e. 0<=my_prow<np_rows, 0<=my_pcol<np_cols and every
+   ! process has a unique (my_prow,my_pcol) pair).
+
+   call set_up_blacsgrid(mpi_comm_world, my_blacs_ctxt, np_rows, np_cols, &
+                         nprow, npcol, my_prow, my_pcol)
+
+   if (myid==0) then
+     print '(a)','| Past BLACS_Gridinfo.'
+   end if
+
+   ! All ELPA routines need MPI communicators for communicating within
+   ! rows or columns of processes, these are set in elpa_get_communicators.
+
+   mpierr = elpa_get_communicators(mpi_comm_world, my_prow, my_pcol, &
+                                   mpi_comm_rows, mpi_comm_cols)
+
+   if (myid==0) then
+     print '(a)','| Past split communicator setup for rows and columns.'
+   end if
+
+   call set_up_blacs_descriptor(na ,nblk, my_prow, my_pcol, np_rows, np_cols, &
+                                na_rows, na_cols, sc_desc, my_blacs_ctxt, info)
+
+   if (myid==0) then
+     print '(a)','| Past scalapack descriptor setup.'
+   end if
+
+   !-------------------------------------------------------------------------------
+   ! Allocate matrices and set up a test matrix for the eigenvalue problem
+#ifdef HAVE_DETAILED_TIMINGS
+   call timer%start("set up matrix")
+#endif
+   allocate(a (na_rows,na_cols))
+   allocate(z (na_rows,na_cols))
+   allocate(as(na_rows,na_cols))
+
+   allocate(ev(na))
+
+   call prepare_matrix_double(na, myid, sc_desc, iseed,  a, z, as)
+
+   ! set values outside of the bandwidth to zero
+   bandwidth = nblk
+
+   do local_row = 1, na_rows
+     global_row = index_l2g( local_row, nblk, my_prow, np_rows )
+     do local_col = 1, na_cols
+       global_col = index_l2g( local_col, nblk, my_pcol, np_cols )
+ 
+       if (ABS(global_row-global_col) > bandwidth) then
+         a(local_row, local_col) = 0.0
+         as(local_row, local_col) = 0.0
+       end if 
+     end do
+   end do 
+
+#ifdef HAVE_DETAILED_TIMINGS
+   call timer%stop("set up matrix")
+#endif
+   ! set print flag in elpa1
+   elpa_print_times = .true.
+
+   !-------------------------------------------------------------------------------
+   ! Calculate eigenvalues/eigenvectors
+
+   if (myid==0) then
+     print '(a)','| Entering two-stage ELPA solver ... '
+     print *
+   end if
+#ifdef WITH_MPI
+   call mpi_barrier(mpi_comm_world, mpierr) ! for correct timings only
+#endif
+   successELPA = elpa_solve_evp_real_2stage_double(na, nev, a, na_rows, ev, z, na_rows,  nblk, na_cols, &
+                                       mpi_comm_rows, mpi_comm_cols, mpi_comm_world, bandwidth = bandwidth)
+
+   if (.not.(successELPA)) then
+      write(error_unit,*) "solve_evp_real_2stage produced an error! Aborting..."
+#ifdef WITH_MPI
+      call MPI_ABORT(mpi_comm_world, 1, mpierr)
+#endif
+   endif
+
+   if (myid==0) then
+     print '(a)','| Two-step ELPA solver complete.'
+     print *
+   end if
+
+   if(myid == 0) print *,'Time transform to tridi :',time_evp_fwd
+   if(myid == 0) print *,'Time solve tridi        :',time_evp_solve
+   if(myid == 0) print *,'Time transform back EVs :',time_evp_back
+   if(myid == 0) print *,'Total time (sum above)  :',time_evp_back+time_evp_solve+time_evp_fwd
+
+
+   if(write_to_file%eigenvectors) then
+     write(unit = task_suffix, fmt = '(i8.8)') myid
+     open(17,file="EVs_real2_out_task_"//task_suffix(1:8)//".txt",form='formatted',status='new')
+     write(17,*) "Part of eigenvectors: na_rows=",na_rows,"of na=",na," na_cols=",na_cols," of na=",na
+
+     do i=1,na_rows
+       do j=1,na_cols
+         write(17,*) "row=",i," col=",j," element of eigenvector=",z(i,j)
+       enddo
+     enddo
+     close(17)
+   endif
+
+   if(write_to_file%eigenvalues) then
+      if (myid == 0) then
+         open(17,file="Eigenvalues_real2_out.txt",form='formatted',status='new')
+         do i=1,na
+            write(17,*) i,ev(i)
+         enddo
+         close(17)
+      endif
+   endif
+
+
+   !-------------------------------------------------------------------------------
+   ! Test correctness of result (using plain scalapack routines)
+   allocate(tmp1(na_rows,na_cols))
+   allocate(tmp2(na_rows,na_cols))
+
+   status = check_correctness(na, nev, as, z, ev, sc_desc, myid, tmp1, tmp2)
+
+   deallocate(a)
+   deallocate(as)
+
+   deallocate(z)
+   deallocate(tmp1)
+   deallocate(tmp2)
+   deallocate(ev)
+
+#ifdef HAVE_DETAILED_TIMINGS
+   call timer%stop("program: test_real2_double_precision")
+   print *," "
+   print *,"Timings program: test_real2_double_precision"
+   call timer%print("program: test_real2_double_precision")
+   print *," "
+   print *,"End timings program: test_real2_double_precision"
+#endif
+#ifdef WITH_MPI
+   call blacs_gridexit(my_blacs_ctxt)
+   call mpi_finalize(mpierr)
+#endif
+   call EXIT(STATUS)
+end
+
+!-------------------------------------------------------------------------------

test/shared/blacs_infrastructure.F90

@@ -156,4 +156,9 @@ module mod_blacs_infrastructure
 
     end subroutine
 
+    integer function index_l2g(idx_loc, nblk, iproc, nprocs)
+     index_l2g = nprocs * nblk * ((idx_loc-1) / nblk) + mod(idx_loc-1,nblk) + mod(nprocs+iproc, nprocs)*nblk + 1
+     return
+    end
+
 end module