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amg4psblas/mlprec/mld_dilu_bld.f90

279 lines
10 KiB
Fortran

!!$
!!$
!!$ MLD2P4
!!$ MultiLevel Domain Decomposition Parallel Preconditioners Package
!!$ based on PSBLAS (Parallel Sparse BLAS v.2.0)
!!$
!!$ (C) Copyright 2007 Alfredo Buttari University of Rome Tor Vergata
!!$ Pasqua D'Ambra ICAR-CNR, Naples
!!$ Daniela di Serafino Second University of Naples
!!$ Salvatore Filippone University of Rome Tor Vergata
!!$
!!$ 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 MLD2P4 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 MLD2P4 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.
!!$
!!$
! File: mld_dilu_bld.f90
!
! Subroutine: mld_dilu_bld
! Version: real
!
! This routine computes an incomplete LU (ILU) factorization of the local part
! of the matrix stored into a. This factorization is used to build the 'base
! preconditioner' (block-Jacobi preconditioner/solver, Additive Schwarz
! preconditioner) corresponding to a certain level of a multilevel preconditioner.
! The following factorizations are available:
! - ILU(k), i.e. ILU factorization with fill-in level k,
! - MILU(k), i.e. modified ILU factorization with fill-in level k,
! - ILU(k,t), i.e. ILU with threshold (i.e. drop tolerance) t and k additional
! entries in each row of the L and U factors with respect to the initial
! sparsity pattern.
! Note that the meaning of k in ILU(k,t) is different from that in ILU(k) and
! MILU(k).
!
! For details on the above factorizations see
! Y. Saad, Iterative Methods for Sparse Linear Systems, Second Edition,
! SIAM, 2003, Chapter 10.
!
! Note that that this routine handles the ILU(0) factorization separately,
! through mld_ilu_fct, for performance reasons.
!
!
! Arguments:
! a - type(psb_dspmat_type), input.
! The sparse matrix structure containing the local matrix to be
! factorized. Note that if p%iprcparm(mld_n_ovr_) > 0, i.e. the
! 'base' Additive Schwarz preconditioner has overlap greater than
! 0, and p%iprcparm(mld_sub_ren_) = 0, i.e. a reordering of the
! matrix has not been performed (see mld_bjac_bld), then a contains
! only the 'original' local part of the matrix to be factorized,
! i.e. the rows of the matrix held by the calling process according
! to the initial data distribution.
! p - type(mld_dbaseprc_type), input/output.
! The 'base preconditioner' data structure. In input, p%iprcparm
! contains information on the type of factorization to be computed.
! In output, p%av(mld_l_pr_) and p%av(mld_u_pr_) contain the
! incomplete L and U factors (without their diagonals), and p%d
! contains the diagonal of the incomplete U factor. For more
! details on p see its description in mld_prec_type.f90.
! info - integer, output.
! Error code.
! blck - type(psb_dspmat_type), input, optional.
! The sparse matrix structure containing the remote rows of the
! matrix to be factorized, that have been retrieved by mld_asmat_bld
! to build an Additive Schwarz base preconditioner with overlap
! greater than 0. If the overlap is 0 or the matrix has been reordered
! (see mld_bjac_bld), then blck does not contain any row.
!
subroutine mld_dilu_bld(a,p,upd,info,blck)
use psb_base_mod
use mld_prec_mod, mld_protect_name => mld_dilu_bld
implicit none
! Arguments
type(psb_dspmat_type), intent(in), target :: a
type(mld_dbaseprc_type), intent(inout) :: p
character, intent(in) :: upd
integer, intent(out) :: info
type(psb_dspmat_type), intent(in), optional :: blck
! Local Variables
integer :: i, nztota, err_act, n_row, nrow_a
character :: trans, unitd
integer :: debug_level, debug_unit
integer :: ictxt,np,me
character(len=20) :: name, ch_err
if(psb_get_errstatus().ne.0) return
info=0
name='mld_dilu_bld'
call psb_erractionsave(err_act)
debug_unit = psb_get_debug_unit()
debug_level = psb_get_debug_level()
ictxt = psb_cd_get_context(p%desc_data)
call psb_info(ictxt, me, np)
if (debug_level >= psb_debug_outer_) &
& write(debug_unit,*) me,' ',trim(name),' start'
trans = 'N'
unitd = 'U'
!
! Check the memory available to hold the incomplete L and U factors
! and allocate it if needed
!
if (allocated(p%av)) then
if (size(p%av) < mld_bp_ilu_avsz_) then
do i=1,size(p%av)
call psb_sp_free(p%av(i),info)
if (info /= 0) then
! Actually, we don't care here about this. Just let it go.
! return
end if
enddo
deallocate(p%av,stat=info)
endif
end if
if (.not.allocated(p%av)) then
allocate(p%av(mld_max_avsz_),stat=info)
if (info /= 0) then
call psb_errpush(4000,name)
goto 9999
end if
endif
nrow_a = psb_sp_get_nrows(a)
nztota = psb_sp_get_nnzeros(a)
if (present(blck)) then
nztota = nztota + psb_sp_get_nnzeros(blck)
end if
if (debug_level >= psb_debug_outer_) &
& write(debug_unit,*) me,' ',trim(name),&
& ': out get_nnzeros',nztota,a%m,a%k,nrow_a
n_row = p%desc_data%matrix_data(psb_n_row_)
p%av(mld_l_pr_)%m = n_row
p%av(mld_l_pr_)%k = n_row
p%av(mld_u_pr_)%m = n_row
p%av(mld_u_pr_)%k = n_row
call psb_sp_all(n_row,n_row,p%av(mld_l_pr_),nztota,info)
if (info == 0) call psb_sp_all(n_row,n_row,p%av(mld_u_pr_),nztota,info)
if(info/=0) then
info=4010
ch_err='psb_sp_all'
call psb_errpush(info,name,a_err=ch_err)
goto 9999
end if
if (allocated(p%d)) then
if (size(p%d) < n_row) then
deallocate(p%d)
endif
endif
if (.not.allocated(p%d)) then
allocate(p%d(n_row),stat=info)
if (info /= 0) then
call psb_errpush(4010,name,a_err='Allocate')
goto 9999
end if
endif
select case(p%iprcparm(mld_sub_solve_))
case (mld_ilu_t_)
!
! ILU(k,t)
!
select case(p%iprcparm(mld_sub_fill_in_))
case(:-1)
! Error: fill-in <= -1
call psb_errpush(30,name,i_err=(/3,p%iprcparm(mld_sub_fill_in_),0,0,0/))
goto 9999
case(0:)
! Fill-in >= 0
call mld_ilut_fct(p%iprcparm(mld_sub_fill_in_),p%dprcparm(mld_fact_thrs_),&
& p%iprcparm(mld_sub_solve_), a,&
& p%av(mld_l_pr_),p%av(mld_u_pr_),p%d,info,blck=blck)
end select
if(info/=0) then
info=4010
ch_err='mld_ilut_fct'
call psb_errpush(info,name,a_err=ch_err)
goto 9999
end if
case(mld_ilu_n_,mld_milu_n_)
!
! ILU(k) and MILU(k)
!
select case(p%iprcparm(mld_sub_fill_in_))
case(:-1)
! Error: fill-in <= -1
call psb_errpush(30,name,i_err=(/3,p%iprcparm(mld_sub_fill_in_),0,0,0/))
goto 9999
case(0)
! Fill-in 0
! Separate implementation of ILU(0) for better performance.
! There seems to be a problem with the separate implementation of MILU(0),
! contained into mld_ilu_fct. This must be investigated. For the time being,
! resort to the implementation of MILU(k) with k=0.
if (p%iprcparm(mld_sub_solve_) == mld_ilu_n_) then
call mld_ilu_fct(p%iprcparm(mld_sub_solve_),a,p%av(mld_l_pr_),p%av(mld_u_pr_),&
& p%d,info,blck=blck)
else
call mld_iluk_fct(p%iprcparm(mld_sub_fill_in_),p%iprcparm(mld_sub_solve_),&
& a,p%av(mld_l_pr_),p%av(mld_u_pr_),p%d,info,blck=blck)
endif
case(1:)
! Fill-in >= 1
! The same routine implements both ILU(k) and MILU(k)
call mld_iluk_fct(p%iprcparm(mld_sub_fill_in_),p%iprcparm(mld_sub_solve_),&
& a,p%av(mld_l_pr_),p%av(mld_u_pr_),p%d,info,blck=blck)
end select
if (info/=0) then
info=4010
ch_err='mld_iluk_fct'
call psb_errpush(info,name,a_err=ch_err)
goto 9999
end if
case default
! If we end up here, something was wrong up in the call chain.
call psb_errpush(4000,name)
goto 9999
end select
if (psb_sp_getifld(psb_upd_,p%av(mld_u_pr_),info) /= psb_upd_perm_) then
call psb_sp_trim(p%av(mld_u_pr_),info)
endif
if (psb_sp_getifld(psb_upd_,p%av(mld_l_pr_),info) /= psb_upd_perm_) then
call psb_sp_trim(p%av(mld_l_pr_),info)
endif
if (debug_level >= psb_debug_outer_) &
& write(debug_unit,*) me,' ',trim(name),' end'
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_dilu_bld