!!$
!!$
!!$ 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
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!!$
! File: mld_zbaseprec_aply.f90
!
! Subroutine: mld_zbaseprec_aply
! Version: complex
!
! This routine applies a base preconditioner by computing
!
! Y = beta*Y + alpha*op(K^(-1))*X,
! where
! - K is the base preconditioner, stored in prec,
! - op(K^(-1)) is K^(-1) or its transpose, according to the value of trans,
! - X and Y are vectors,
! - alpha and beta are scalars.
!
! The routine is used by mld_dmlprec_aply, to apply the multilevel preconditioners,
! or directly by mld_dprec_aply, to apply the basic one-level preconditioners (diagonal,
! block-Jacobi or additive Schwarz), or to have no preconditioning.
!
!
! Arguments:
! alpha - complex(kind(0.d0)), input.
! The scalar alpha.
! prec - type(mld_zbaseprc_type), input.
! The base preconditioner data structure containing the local part
! of the preconditioner K.
! x - complex(kind(0.d0)), dimension(:), input.
! The local part of the vector X.
! beta - complex(kind(0.d0)), input.
! The scalar beta.
! y - complex(kind(0.d0)), dimension(:), input/output.
! The local part of the vector Y.
! desc_data - type(psb_desc_type), input.
! The communication descriptor associated to the matrix to be
! preconditioned.
! trans - character, optional.
! If trans='N','n' then op(K^(-1)) = K^(-1);
! if trans='T','t' then op(K^(-1)) = K^(-T) (transpose of K^(-1)).
! work - real(kind(0.d0)), dimension (:), optional, target.
! Workspace. Its size must be at least 4*psb_cd_get_local_cols(desc_data).
! info - integer, output.
! Error code.
!
subroutine mld_zbaseprec_aply(alpha,prec,x,beta,y,desc_data,trans,work,info)
use psb_base_mod
use mld_prec_mod, mld_protect_name => mld_zbaseprec_aply
implicit none
! Arguments
type(psb_desc_type),intent(in) :: desc_data
type(mld_zbaseprc_type), intent(in) :: prec
complex(kind(0.d0)),intent(in) :: x(:)
complex(kind(0.d0)),intent(inout) :: y(:)
complex(kind(0.d0)),intent(in) :: alpha,beta
character(len=1) :: trans
complex(kind(0.d0)),target :: work(:)
integer, intent(out) :: info
! Local variables
integer :: n_row,n_col, int_err(5), nrow_d
complex(kind(1.d0)), pointer :: ww(:), aux(:), tx(:),ty(:)
integer :: ictxt,np,me,isz, err_act
character(len=20) :: name, ch_err
name='mld_zbaseprec_aply'
info = 0
call psb_erractionsave(err_act)
ictxt = psb_cd_get_context(desc_data)
call psb_info(ictxt, me, np)
select case(trans)
case('N','n')
case('T','t','C','c')
case default
info=40
int_err(1)=6
ch_err(2:2)=trans
goto 9999
end select
select case(prec%iprcparm(mld_prec_type_))
case(mld_noprec_)
!
! No preconditioner
!
call psb_geaxpby(alpha,x,beta,y,desc_data,info)
case(mld_diag_)
!
! Diagonal preconditioner
!
if (size(work) >= size(x)) then
ww => work
else
allocate(ww(size(x)),stat=info)
if (info /= 0) then
call psb_errpush(4025,name,i_err=(/size(x),0,0,0,0/),a_err='complex(kind(1.d0))')
goto 9999
end if
end if
n_row = psb_cd_get_local_rows(desc_data)
ww(1:n_row) = x(1:n_row)*prec%d(1:n_row)
call psb_geaxpby(alpha,ww,beta,y,desc_data,info)
if (size(work) < size(x)) then
deallocate(ww,stat=info)
if (info /= 0) then
call psb_errpush(4010,name,a_err='Deallocate')
goto 9999
end if
end if
case(mld_bjac_)
!
! Block-Jacobi preconditioner
!
call mld_bjac_aply(alpha,prec,x,beta,y,desc_data,trans,work,info)
if(info /= 0) then
info=4010
ch_err='mld_bjac_aply'
goto 9999
end if
case(mld_as_)
!
! Additive Schwarz preconditioner
!
if (prec%iprcparm(mld_n_ovr_)==0) then
!
! shortcut: this fixes performance for RAS(0) == BJA
!
call mld_bjac_aply(alpha,prec,x,beta,y,desc_data,trans,work,info)
if(info /= 0) then
info=4010
ch_err='psb_bjacaply'
goto 9999
end if
else
!
! Note: currently trans is unused
!
n_row = psb_cd_get_local_rows(prec%desc_data)
n_col = psb_cd_get_local_cols(prec%desc_data)
nrow_d = psb_cd_get_local_rows(desc_data)
isz=max(n_row,N_COL)
if ((6*isz) <= size(work)) then
ww => work(1:isz)
tx => work(isz+1:2*isz)
ty => work(2*isz+1:3*isz)
aux => work(3*isz+1:)
else if ((4*isz) <= size(work)) then
aux => work(1:)
allocate(ww(isz),tx(isz),ty(isz),stat=info)
if (info /= 0) then
call psb_errpush(4025,name,i_err=(/3*isz,0,0,0,0/),&
& a_err='complex(kind(1.d0))')
goto 9999
end if
else if ((3*isz) <= size(work)) then
ww => work(1:isz)
tx => work(isz+1:2*isz)
ty => work(2*isz+1:3*isz)
allocate(aux(4*isz),stat=info)
if (info /= 0) then
call psb_errpush(4025,name,i_err=(/4*isz,0,0,0,0/),&
& a_err='complex(kind(1.d0))')
goto 9999
end if
else
allocate(ww(isz),tx(isz),ty(isz),&
&aux(4*isz),stat=info)
if (info /= 0) then
call psb_errpush(4025,name,i_err=(/4*isz,0,0,0,0/),&
& a_err='complex(kind(1.d0))')
goto 9999
end if
endif
tx(1:nrow_d) = x(1:nrow_d)
tx(nrow_d+1:isz) = zzero
!
! Get the overlap entries of tx (tx==x)
!
if (prec%iprcparm(mld_sub_restr_)==psb_halo_) then
call psb_halo(tx,prec%desc_data,info,work=aux,data=psb_comm_ext_)
if(info /=0) then
info=4010
ch_err='psb_halo'
goto 9999
end if
else if (prec%iprcparm(mld_sub_restr_) /= psb_none_) then
call psb_errpush(4001,name,a_err='Invalid mld_sub_restr_')
goto 9999
end if
!
! If required, reorder tx according to the row/column permutation of the
! local extended matrix, stored into the permutation vector prec%perm
!
if (prec%iprcparm(mld_sub_ren_)>0) then
call psb_gelp('n',prec%perm,tx,info)
if(info /=0) then
info=4010
ch_err='psb_gelp'
goto 9999
end if
endif
!
! Apply to tx the block-Jacobi preconditioner/solver (multiple sweeps of the
! block-Jacobi solver can be applied at the coarsest level of a multilevel
! preconditioner). The resulting vector is ty.
!
call mld_bjac_aply(zone,prec,tx,zzero,ty,prec%desc_data,trans,aux,info)
if(info /= 0) then
info=4010
ch_err='mld_bjac_aply'
goto 9999
end if
!
! Apply to ty the inverse permutation of prec%perm
!
if (prec%iprcparm(mld_sub_ren_)>0) then
call psb_gelp('n',prec%invperm,ty,info)
if(info /=0) then
info=4010
ch_err='psb_gelp'
goto 9999
end if
endif
select case (prec%iprcparm(mld_sub_prol_))
case(psb_none_)
!
! Would work anyway, but since it is supposed to do nothing ...
! call psb_ovrl(ty,prec%desc_data,info,&
! & update=prec%iprcparm(mld_sub_prol_),work=aux)
case(psb_sum_,psb_avg_)
!
! Update the overlap of ty
!
call psb_ovrl(ty,prec%desc_data,info,&
& update=prec%iprcparm(mld_sub_prol_),work=aux)
if(info /=0) then
info=4010
ch_err='psb_ovrl'
goto 9999
end if
case default
call psb_errpush(4001,name,a_err='Invalid mld_sub_prol_')
goto 9999
end select
!
! Compute y = beta*y + alpha*ty (ty==K^(-1)*tx)
!
call psb_geaxpby(alpha,ty,beta,y,desc_data,info)
if ((6*isz) <= size(work)) then
else if ((4*isz) <= size(work)) then
deallocate(ww,tx,ty)
else if ((3*isz) <= size(work)) then
deallocate(aux)
else
deallocate(ww,aux,tx,ty)
endif
end if
case default
call psb_errpush(4001,name,a_err='Invalid mld_prec_type_')
goto 9999
end select
call psb_erractionrestore(err_act)
return
9999 continue
call psb_errpush(info,name,i_err=int_err,a_err=ch_err)
call psb_erractionrestore(err_act)
if (err_act == psb_act_abort_) then
call psb_error()
return
end if
return
end subroutine mld_zbaseprec_aply