psblas3/base/tools/psb_cdrep.f90

!   
!                Parallel Sparse BLAS  version 3.5
!      (C) Copyright 2006-2018
!        Salvatore Filippone    
!        Alfredo Buttari      
!   
!    Redistribution and use in source and binary forms, with or without
!    modification, are permitted provided that the following conditions
!    are met:
!      1. Redistributions of source code must retain the above copyright
!         notice, this list of conditions and the following disclaimer.
!      2. Redistributions in binary form must reproduce the above copyright
!         notice, this list of conditions, and the following disclaimer in the
!         documentation and/or other materials provided with the distribution.
!      3. The name of the PSBLAS group or the names of its contributors may
!         not be used to endorse or promote products derived from this
!         software without specific written permission.
!   
!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PSBLAS GROUP OR ITS CONTRIBUTORS
!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
!    POSSIBILITY OF SUCH DAMAGE.
!   
!    
!  Purpose
!  == = ====
!  
!  Allocate special descriptor for replicated index space.
! 
!
!
! INPUT
! == ====
! M                 :(Global Input) Integer 
!                    Total number of  equations
!                    required.
!
! ctxt      : (Global Input)Integer BLACS context for an NPx1 grid 
!                required.
!
! OUTPUT
! == =======
! desc   : TYPEDESC
! desc OUTPUT FIELDS:
!
! MATRIX_DATA   : Pointer to integer Array 
!                contains some
!               local and global information about matrix:
!
!  NOTATION        STORED IN		     EXPLANATION
!  ------------ ---------------------- -------------------------------------
!  DEC_TYPE        MATRIX_DATA[DEC_TYPE_]   Decomposition type, temporarly is
!                      setted to 1( matrix not yet assembled)
!  M 	             MATRIX_DATA[M_]          Total number of equations
!  N 	             MATRIX_DATA[N_]          Total number of variables
!  N_ROW           MATRIX_DATA[N_ROW_]      Number of local equations
!  N_COL           MATRIX_DATA[N_COL_]      Number of local columns (see below)
!  CTXT_A          MATRIX_DATA[CTXT_]     The BLACS context handle, 
!                                         indicating
!	  			            the global context of the operation
!					    on the matrix.
!					    The context itself is global.
!
!  GLOB_TO_LOC     Array of dimension equal to number of global 
!                  rows/cols (MATRIX_DATA[M_]). On exit,
!                  for all global indices either:
!                  1. The index belongs to the current process; the entry
!                     is set to the next free local row index.
!                  2. The index belongs to process P (0<=P<=NP-1); the entry 
!                     is set to 
!                     -(NP+P+1)
!
!  LOC_TO_GLOB     An array of dimension equal to number of local cols N_COL
!                  i.e. all columns of the matrix such that there is at least
!                  one nonzero entry within the local row range. At the time 
!                  this routine is called N_COL cannot be know, so we set 
!                  N_COL=N_ROW, and dimension this vector on N_ROW plus an 
!                  estimate. On exit the vector elements are set
!                  to the index of the corresponding entry in GLOB_TO_LOC, or  
!                  to -1 for indices I>N_ROW.
!
!
!  HALO_INDEX      Not touched here, as it depends on the matrix pattern
!
!  OVRLAP_INDEX    On exit from this routine, the overlap indices are stored in
!                  triples (Proc, 1, Index), similar to the assembled format 
!                  but neither optimized, nor deadlock free. 
!                  List is terminated with -1
!
!  OVRLAP_ELEM     On exit from this routine, just a list of pairs (index,#p).
!                  List is terminated with -1.
!                  
!
! END OF desc OUTPUT FIELDS
!
!
subroutine psb_cdrep(m, ctxt, desc, info)
  use psb_base_mod
  use psi_mod
  use psb_repl_map_mod
  implicit None
  !....Parameters...
  integer(psb_lpk_), intent(in)    :: m
  type(psb_ctxt_type), intent(in)  :: ctxt
  integer(psb_ipk_), intent(out)   :: info
  Type(psb_desc_type), intent(out) :: desc

  !locals
  integer(psb_ipk_) :: i,np,me,err,err_act
  integer(psb_lpk_) :: n
  integer(psb_lpk_) :: l_err(5),exch(2)
  integer(psb_ipk_) :: thalo(1), tovr(1), text(1)
  integer(psb_ipk_) :: debug_level, debug_unit
  character(len=20)   :: name

  if(psb_get_errstatus() /= 0) return 
  info=psb_success_
  err=0
  name = 'psb_cdrep'
  debug_unit  = psb_get_debug_unit()
  debug_level = psb_get_debug_level()

  call psb_info(ctxt, me, np)
  if (debug_level >= psb_debug_ext_) &
       & write(debug_unit,*) me,' ',trim(name),': ',np
  n = m
  !... check m and n parameters....
  if (m < 1) then
    info = psb_err_iarg_neg_
    l_err(1) = 1
    l_err(2) = m
  else if (n < 1) then
    info = psb_err_iarg_neg_
    l_err(1) = 2
    l_err(2) = n
  endif

  if (info /= psb_success_) then 
    call psb_errpush(info,name,l_err=l_err)
    goto 9999
  end if

  if (debug_level >= psb_debug_ext_) &
       & write(debug_unit,*) me,' ',trim(name),':  doing global checks'  
  !global check on m and n parameters
  if (me == psb_root_) then
    exch(1)=m
    exch(2)=n
    call psb_bcast(ctxt,exch(1:2),root=psb_root_)
  else
    call psb_bcast(ctxt,exch(1:2),root=psb_root_)
    if (exch(1) /= m) then
      info=psb_err_parm_differs_among_procs_
      l_err(1)=1
    else if (exch(2) /= n) then
      info=psb_err_parm_differs_among_procs_
      l_err(1)=2
    endif
  endif

  if (info /= psb_success_) then 
    call psb_errpush(info,name,l_err=l_err)
    goto 9999
  end if


  call psb_nullify_desc(desc)


  !count local rows number
  ! allocate work vector

  allocate(psb_repl_map :: desc%indxmap, stat=info)
  select type(aa => desc%indxmap) 
  type is (psb_repl_map) 
    call aa%repl_map_init(ctxt,m,info)
  class default 
    ! This cannot happen 
    info = psb_err_internal_error_
    call psb_errpush(info,name)
    Goto 9999
  end select
   

  tovr  = -1 
  call psi_bld_tmpovrl(tovr,desc,info)

  if (debug_level >= psb_debug_ext_) &
       & write(debug_unit,*) me,' ',trim(name),': end'

  call psb_erractionrestore(err_act)
  return

9999 call psb_error_handler(ctxt,err_act)

  return
end subroutine psb_cdrep