!!$
!!$
!!$ MD2P4
!!$ Multilevel Domain Decomposition Parallel Preconditioner Package for PSBLAS
!!$ for
!!$ Parallel Sparse BLAS v2.0
!!$ (C) Copyright 2006 Salvatore Filippone University of Rome Tor Vergata
!!$ Alfredo Buttari University of Rome Tor Vergata
!!$ Daniela di Serafino Second University of Naples
!!$ Pasqua D'Ambra ICAR-CNR
!!$
!!$ 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 MD2P4 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 MD2P4 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.
!!$
!!$
subroutine mld_daggrmap_bld(aggr_type,a,desc_a,nlaggr,ilaggr,info)
use psb_base_mod
use psb_prec_mod, mld_protect_name => mld_daggrmap_bld
implicit none
integer, intent(in) :: aggr_type
type(psb_dspmat_type), intent(in) :: a
type(psb_desc_type), intent(in) :: desc_a
integer, allocatable :: ilaggr(:),nlaggr(:)
integer, intent(out) :: info
! Locals
integer, allocatable :: ils(:), neigh(:)
integer :: icnt,nlp,k,n,ia,isz,nr, naggr,i,j,m
logical :: recovery
logical, parameter :: debug=.false.
integer ::ictxt,np,me,err_act
integer :: nrow, ncol, n_ne
integer, parameter :: one=1, two=2
character(len=20) :: name, ch_err
if(psb_get_errstatus().ne.0) return
info=0
name = 'mld_daggrmap_bld'
call psb_erractionsave(err_act)
!
! Note. At the time being we are ignoring aggr_type
! so that we only have local decoupled aggregation. This might
! change in the future.
!
ictxt=psb_cd_get_context(desc_a)
call psb_info(ictxt,me,np)
nrow = psb_cd_get_local_rows(desc_a)
ncol = psb_cd_get_local_cols(desc_a)
nr = a%m
allocate(ilaggr(nr),neigh(nr),stat=info)
if(info.ne.0) then
info=4025
call psb_errpush(info,name,i_err=(/2*nr,0,0,0,0/),&
& a_err='integer')
goto 9999
end if
do i=1, nr
ilaggr(i) = -(nr+1)
end do
! Note: -(nr+1) Untouched as yet
! -i 1<=i<=nr Adjacent to aggregate i
! i 1<=i<=nr Belonging to aggregate i
!
! Phase one: group nodes together.
! Very simple minded strategy.
!
naggr = 0
nlp = 0
do
icnt = 0
do i=1, nr
if (ilaggr(i) == -(nr+1)) then
!
! 1. Untouched nodes are marked >0 together
! with their neighbours
!
icnt = icnt + 1
naggr = naggr + 1
ilaggr(i) = naggr
call psb_neigh(a,i,neigh,n_ne,info,lev=one)
if (info/=0) then
info=4010
ch_err='psb_neigh'
call psb_errpush(info,name,a_err=ch_err)
goto 9999
end if
do k=1, n_ne
j = neigh(k)
if ((1<=j).and.(j<=nr)) then
ilaggr(j) = naggr
!!$ if (ilaggr(j) < 0) ilaggr(j) = naggr
!!$ if (ilaggr(j) == -(nr+1)) ilaggr(j) = naggr
endif
enddo
!
! 2. Untouched neighbours of these nodes are marked <0.
!
call psb_neigh(a,i,neigh,n_ne,info,lev=two)
if (info/=0) then
info=4010
ch_err='psb_neigh'
call psb_errpush(info,name,a_err=ch_err)
goto 9999
end if
do n = 1, n_ne
m = neigh(n)
if ((1<=m).and.(m<=nr)) then
if (ilaggr(m) == -(nr+1)) ilaggr(m) = -naggr
endif
enddo
endif
enddo
nlp = nlp + 1
if (icnt == 0) exit
enddo
if (debug) then
write(0,*) 'Check 1:',count(ilaggr == -(nr+1)),(a%ia1(i),i=a%ia2(1),a%ia2(2)-1)
end if
!
! Phase two: sweep over leftovers.
!
allocate(ils(naggr+10),stat=info)
if(info.ne.0) then
info=4025
call psb_errpush(info,name,i_err=(/naggr+10,0,0,0,0/),&
& a_err='integer')
goto 9999
end if
do i=1, size(ils)
ils(i) = 0
end do
do i=1, nr
n = ilaggr(i)
if (n>0) then
if (n>naggr) then
write(0,*) 'loc_Aggregate: n > naggr 1 ? ',n,naggr
else
ils(n) = ils(n) + 1
end if
end if
end do
if (debug) then
write(0,*) 'Phase 1: number of aggregates ',naggr
write(0,*) 'Phase 1: nodes aggregated ',sum(ils)
end if
recovery=.false.
do i=1, nr
if (ilaggr(i) < 0) then
!
! Now some silly rule to break ties:
! Group with smallest adjacent aggregate.
!
isz = nr+1
ia = -1
call psb_neigh(a,i,neigh,n_ne,info,lev=one)
if (info/=0) then
info=4010
ch_err='psb_neigh'
call psb_errpush(info,name,a_err=ch_err)
goto 9999
end if
do j=1, n_ne
k = neigh(j)
if ((1<=k).and.(k<=nr)) then
n = ilaggr(k)
if (n>0) then
if (n>naggr) then
write(0,*) 'loc_Aggregate: n > naggr 2? ',n,naggr
end if
if (ils(n) < isz) then
ia = n
isz = ils(n)
endif
endif
endif
enddo
if (ia == -1) then
if (ilaggr(i) > -(nr+1)) then
ilaggr(i) = abs(ilaggr(i))
if (ilaggr(I)>naggr) then
write(0,*) 'loc_Aggregate: n > naggr 3? ',ilaggr(i),naggr
end if
ils(ilaggr(i)) = ils(ilaggr(i)) + 1
!
! This might happen if the pattern is non symmetric.
! Need a better handling.
!
recovery = .true.
else
write(0,*) 'Unrecoverable error !!',ilaggr(i), nr
endif
else
ilaggr(i) = ia
if (ia>naggr) then
write(0,*) 'loc_Aggregate: n > naggr 4? ',ia,naggr
end if
ils(ia) = ils(ia) + 1
endif
end if
enddo
if (recovery) then
write(0,*) 'Had to recover from strange situation in loc_aggregate.'
write(0,*) 'Perhaps an unsymmetric pattern?'
endif
if (debug) then
write(0,*) 'Phase 2: number of aggregates ',naggr
write(0,*) 'Phase 2: nodes aggregated ',sum(ils)
do i=1, naggr
write(*,*) 'Size of aggregate ',i,' :',count(ilaggr==i), ils(i)
enddo
write(*,*) maxval(ils(1:naggr))
write(*,*) 'Leftovers ',count(ilaggr<0), ' in ',nlp,' loops'
end if
!!$ write(0,*) 'desc_a loc_aggr 4 : ', desc_a%matrix_data(m_)
if (count(ilaggr<0) >0) then
write(0,*) 'Fatal error: some leftovers!!!'
endif
deallocate(ils,neigh,stat=info)
if (info/=0) then
info=4000
call psb_errpush(info,name)
goto 9999
end if
if (nrow /= size(ilaggr)) then
write(0,*) 'SOmething wrong ilaggr ',nrow,size(ilaggr)
endif
call psb_realloc(ncol,ilaggr,info)
if (info/=0) then
info=4010
ch_err='psb_realloc'
call psb_errpush(info,name,a_err=ch_err)
goto 9999
end if
allocate(nlaggr(np),stat=info)
if (info/=0) then
info=4025
call psb_errpush(info,name,i_err=(/np,0,0,0,0/),&
& a_err='integer')
goto 9999
end if
nlaggr(:) = 0
nlaggr(me+1) = naggr
call psb_sum(ictxt,nlaggr(1:np))
call psb_erractionrestore(err_act)
return
9999 continue
call psb_erractionrestore(err_act)
if (err_act.eq.psb_act_abort_) then
call psb_error()
return
end if
return
end subroutine mld_daggrmap_bld