amg4psblas/mlprec/impl/mld_c_as_smoother_impl.f90

!!$
!!$ 
!!$                           MLD2P4  version 2.0
!!$  MultiLevel Domain Decomposition Parallel Preconditioners Package
!!$             based on PSBLAS (Parallel Sparse BLAS version 3.0)
!!$  
!!$  (C) Copyright 2008,2009,2010,2012
!!$
!!$                      Salvatore Filippone  University of Rome Tor Vergata
!!$                      Alfredo Buttari      CNRS-IRIT, Toulouse
!!$                      Pasqua D'Ambra       ICAR-CNR, Naples
!!$                      Daniela di Serafino  Second University of Naples
!!$ 
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!!$  modification, are permitted provided that the following conditions
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!!$    3. The name of the MLD2P4 group or the names of its contributors may
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!
!
!
!
!
!

subroutine mld_c_as_smoother_check(sm,info)

  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_check

  Implicit None

  ! Arguments
  class(mld_c_as_smoother_type), intent(inout) :: sm 
  integer, intent(out)                   :: info
  Integer           :: err_act
  character(len=20) :: name='c_as_smoother_check'

  call psb_erractionsave(err_act)
  info = psb_success_

  call mld_check_def(sm%restr,&
       & 'Restrictor',psb_halo_,is_legal_restrict)
  call mld_check_def(sm%prol,&
       & 'Prolongator',psb_none_,is_legal_prolong)
  call mld_check_def(sm%novr,&
       & 'Overlap layers ',0,is_legal_n_ovr)


  if (allocated(sm%sv)) then 
    call sm%sv%check(info)
  else 
    info=3111
    call psb_errpush(info,name)
    goto 9999
  end if

  if (info /= psb_success_) goto 9999

  call psb_erractionrestore(err_act)
  return

9999 continue
  call psb_erractionrestore(err_act)
  if (err_act == psb_act_abort_) then
    call psb_error()
    return
  end if
  return
end subroutine mld_c_as_smoother_check

subroutine mld_c_as_smoother_apply_vect(alpha,sm,x,beta,y,desc_data,trans,sweeps,work,info)
  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_apply_vect
  implicit none 
  type(psb_desc_type), intent(in)              :: desc_data
  class(mld_c_as_smoother_type), intent(inout) :: sm
  type(psb_c_vect_type),intent(inout)          :: x
  type(psb_c_vect_type),intent(inout)          :: y
  complex(psb_spk_),intent(in)                    :: alpha,beta
  character(len=1),intent(in)                  :: trans
  integer, intent(in)                          :: sweeps
  complex(psb_spk_),target, intent(inout)         :: work(:)
  integer, intent(out)                         :: info

  integer    :: n_row,n_col, nrow_d, i
  complex(psb_spk_), pointer :: ww(:), aux(:), tx(:),ty(:)
  complex(psb_spk_), allocatable :: vx(:) 
  type(psb_c_vect_type) :: vtx, vty, vww
  integer    :: ictxt,np,me, err_act,isz,int_err(5)
  character          :: trans_
  character(len=20)  :: name='c_as_smoother_apply', ch_err

  call psb_erractionsave(err_act)

  info  = psb_success_
  ictxt = desc_data%get_context()
  call psb_info(ictxt,me,np)

  trans_ = psb_toupper(trans)
  select case(trans_)
  case('N')
  case('T')
  case('C')
  case default
    call psb_errpush(psb_err_iarg_invalid_i_,name)
    goto 9999
  end select

  if (.not.allocated(sm%sv)) then 
    info = 1121
    call psb_errpush(info,name)
    goto 9999
  end if


  n_row  = sm%desc_data%get_local_rows()
  n_col  = sm%desc_data%get_local_cols()
  nrow_d = desc_data%get_local_rows()
  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 /= psb_success_) then 
      call psb_errpush(psb_err_alloc_request_,name,i_err=(/3*isz,0,0,0,0/),&
           & a_err='complex(psb_spk_)')
      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 /= psb_success_) then 
      call psb_errpush(psb_err_alloc_request_,name,i_err=(/4*isz,0,0,0,0/),&
           & a_err='complex(psb_spk_)')
      goto 9999      
    end if
  else 
    allocate(ww(isz),tx(isz),ty(isz),&
         &aux(4*isz),stat=info)
    if (info /= psb_success_) then 
      call psb_errpush(psb_err_alloc_request_,name,i_err=(/4*isz,0,0,0,0/),&
           & a_err='complex(psb_spk_)')
      goto 9999      
    end if

  endif

  if ((sm%novr == 0).and.(sweeps == 1)) then 
    !
    ! Shortcut: in this case it's just the same
    ! as Block Jacobi.
    !
    call sm%sv%apply(alpha,x,beta,y,desc_data,trans_,aux,info) 

    if (info /= psb_success_) then
      call psb_errpush(psb_err_internal_error_,name,&
           & a_err='Error in sub_aply Jacobi Sweeps = 1')
      goto 9999
    endif

  else 


    vx = x%get_vect()

    call psb_geall(vtx,sm%desc_data,info)
    call psb_geasb(vtx,sm%desc_data,info,mold=x%v) 
    call psb_geall(vty,sm%desc_data,info)
    call psb_geasb(vty,sm%desc_data,info,mold=x%v) 
    call psb_geall(vww,sm%desc_data,info)
    call psb_geasb(vww,sm%desc_data,info,mold=x%v) 
    call vtx%set(czero)
    call vty%set(czero)
    call vww%set(czero)


    call vtx%set(vx(1:nrow_d))

    if (sweeps == 1) then 

      select case(trans_)
      case('N')
        !
        ! Get the overlap entries of tx (tx == x)
        ! 
        if (sm%restr == psb_halo_) then 
          call psb_halo(vtx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_halo'
            goto 9999
          end if
        else if (sm%restr /= psb_none_) then 
          call psb_errpush(psb_err_internal_error_,name,&
               & a_err='Invalid mld_sub_restr_')
          goto 9999
        end if


      case('T','C')
        !
        ! With transpose, we have to do it here
        ! 

        select case (sm%prol) 

        case(psb_none_)
          ! 
          ! Do nothing

        case(psb_sum_) 
          !
          ! The transpose of sum is halo
          !
          call psb_halo(vtx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_halo'
            goto 9999
          end if

        case(psb_avg_) 
          !
          ! Tricky one: first we have to scale the overlap entries,
          ! which we can do by assignind mode=0, i.e. no communication
          ! (hence only scaling), then we do the halo
          !
          call psb_ovrl(vtx,sm%desc_data,info,&
               & update=psb_avg_,work=aux,mode=0)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_ovrl'
            goto 9999
          end if
          call psb_halo(vtx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_halo'
            goto 9999
          end if

        case default
          call psb_errpush(psb_err_internal_error_,name,&
               & a_err='Invalid mld_sub_prol_')
          goto 9999
        end select


      case default
        info=psb_err_iarg_invalid_i_
        int_err(1)=6
        ch_err(2:2)=trans
        goto 9999
      end select

      call sm%sv%apply(cone,vtx,czero,vty,sm%desc_data,trans_,aux,info) 

      if (info /= psb_success_) then
        call psb_errpush(psb_err_internal_error_,name,&
             & a_err='Error in sub_aply Jacobi Sweeps = 1')
        goto 9999
      endif

      select case(trans_)
      case('N')

        select case (sm%prol) 

        case(psb_none_)
          ! 
          ! Would work anyway, but since it is supposed to do nothing ...
          !        call psb_ovrl(ty,sm%desc_data,info,&
          !             & update=sm%prol,work=aux)


        case(psb_sum_,psb_avg_) 
          !
          ! Update the overlap of ty
          !
          call psb_ovrl(vty,sm%desc_data,info,&
               & update=sm%prol,work=aux)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_ovrl'
            goto 9999
          end if

        case default
          call psb_errpush(psb_err_internal_error_,name,&
               & a_err='Invalid mld_sub_prol_')
          goto 9999
        end select

      case('T','C')
        !
        ! With transpose, we have to do it here
        ! 
        if (sm%restr == psb_halo_) then 
          call psb_ovrl(vty,sm%desc_data,info,&
               & update=psb_sum_,work=aux)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_ovrl'
            goto 9999
          end if
        else if (sm%restr /= psb_none_) then 
          call psb_errpush(psb_err_internal_error_,name,&
               & a_err='Invalid mld_sub_restr_')
          goto 9999
        end if

      case default
        info=psb_err_iarg_invalid_i_
        int_err(1)=6
        ch_err(2:2)=trans
        goto 9999
      end select



    else if (sweeps  > 1) then 

      !
      !
      ! Apply prec%iprcparm(mld_smoother_sweeps_) sweeps of a block-Jacobi solver
      ! to compute an approximate solution of a linear system.
      !
      !
      call vty%set(czero)

      do i=1, sweeps
        select case(trans_)
        case('N')
          !
          ! Get the overlap entries of tx (tx == x)
          ! 
          if (sm%restr == psb_halo_) then 
            call psb_halo(vtx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_halo'
              goto 9999
            end if
          else if (sm%restr /= psb_none_) then 
            call psb_errpush(psb_err_internal_error_,name,&
                 & a_err='Invalid mld_sub_restr_')
            goto 9999
          end if


        case('T','C')
          !
          ! With transpose, we have to do it here
          ! 

          select case (sm%prol) 

          case(psb_none_)
            ! 
            ! Do nothing

          case(psb_sum_) 
            !
            ! The transpose of sum is halo
            !
            call psb_halo(vtx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_halo'
              goto 9999
            end if

          case(psb_avg_) 
            !
            ! Tricky one: first we have to scale the overlap entries,
            ! which we can do by assignind mode=0, i.e. no communication
            ! (hence only scaling), then we do the halo
            !
            call psb_ovrl(vtx,sm%desc_data,info,&
                 & update=psb_avg_,work=aux,mode=0)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_ovrl'
              goto 9999
            end if
            call psb_halo(vtx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_halo'
              goto 9999
            end if

          case default
            call psb_errpush(psb_err_internal_error_,name,&
                 & a_err='Invalid mld_sub_prol_')
            goto 9999
          end select


        case default
          info=psb_err_iarg_invalid_i_
          int_err(1)=6
          ch_err(2:2)=trans
          goto 9999
        end select
        !
        ! Compute Y(j+1) = D^(-1)*(X-ND*Y(j)), where D and ND are the
        ! block diagonal part and the remaining part of the local matrix
        ! and Y(j) is the approximate solution at sweep j.
        !
        call psb_geaxpby(cone,vtx,czero,vww,sm%desc_data,info)
        call psb_spmm(-cone,sm%nd,vty,cone,vww,sm%desc_data,info,&
             & work=aux,trans=trans_)

        if (info /= psb_success_) exit

        call sm%sv%apply(cone,vww,czero,vty,sm%desc_data,trans_,aux,info) 

        if (info /= psb_success_) exit


        select case(trans_)
        case('N')

          select case (sm%prol) 

          case(psb_none_)
            ! 
            ! Would work anyway, but since it is supposed to do nothing ...
            !        call psb_ovrl(ty,sm%desc_data,info,&
            !             & update=sm%prol,work=aux)


          case(psb_sum_,psb_avg_) 
            !
            ! Update the overlap of ty
            !
            call psb_ovrl(vty,sm%desc_data,info,&
                 & update=sm%prol,work=aux)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_ovrl'
              goto 9999
            end if

          case default
            call psb_errpush(psb_err_internal_error_,name,&
                 & a_err='Invalid mld_sub_prol_')
            goto 9999
          end select

        case('T','C')
          !
          ! With transpose, we have to do it here
          ! 
          if (sm%restr == psb_halo_) then 
            call psb_ovrl(vty,sm%desc_data,info,&
                 & update=psb_sum_,work=aux)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_ovrl'
              goto 9999
            end if
          else if (sm%restr /= psb_none_) then 
            call psb_errpush(psb_err_internal_error_,name,&
                 & a_err='Invalid mld_sub_restr_')
            goto 9999
          end if

        case default
          info=psb_err_iarg_invalid_i_
          int_err(1)=6
          ch_err(2:2)=trans
          goto 9999
        end select
      end do

      if (info /= psb_success_) then 
        info=psb_err_internal_error_
        call psb_errpush(info,name,&
             & a_err='subsolve with Jacobi sweeps > 1')
        goto 9999      
      end if


    else

      info = psb_err_iarg_neg_
      call psb_errpush(info,name,&
           & i_err=(/2,sweeps,0,0,0/))
      goto 9999


    end if

    !
    ! Compute y = beta*y + alpha*ty (ty == K^(-1)*tx)
    !
    call psb_geaxpby(alpha,vty,beta,y,desc_data,info) 

  end if


  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
  call vww%free(info)
  call vtx%free(info)
  call vty%free(info)

  call psb_erractionrestore(err_act)
  return

9999 continue
  call psb_erractionrestore(err_act)
  if (err_act == psb_act_abort_) then
    call psb_error()
    return
  end if
  return

end subroutine mld_c_as_smoother_apply_vect


subroutine mld_c_as_smoother_apply(alpha,sm,x,beta,y,desc_data,trans,sweeps,work,info)
  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_apply
  implicit none 
  type(psb_desc_type), intent(in)      :: desc_data
  class(mld_c_as_smoother_type), intent(in) :: sm
  complex(psb_spk_),intent(inout)         :: x(:)
  complex(psb_spk_),intent(inout)         :: y(:)
  complex(psb_spk_),intent(in)            :: alpha,beta
  character(len=1),intent(in)          :: trans
  integer, intent(in)                  :: sweeps
  complex(psb_spk_),target, intent(inout) :: work(:)
  integer, intent(out)                 :: info

  integer    :: n_row,n_col, nrow_d, i
  complex(psb_spk_), pointer :: ww(:), aux(:), tx(:),ty(:)
  integer    :: ictxt,np,me, err_act,isz,int_err(5)
  character          :: trans_
  character(len=20)  :: name='c_as_smoother_apply', ch_err

  call psb_erractionsave(err_act)

  info = psb_success_
  ictxt = desc_data%get_context()
  call psb_info (ictxt,me,np)

  trans_ = psb_toupper(trans)
  select case(trans_)
  case('N')
  case('T')
  case('C')
  case default
    call psb_errpush(psb_err_iarg_invalid_i_,name)
    goto 9999
  end select

  if (.not.allocated(sm%sv)) then 
    info = 1121
    call psb_errpush(info,name)
    goto 9999
  end if


  n_row = sm%desc_data%get_local_rows()
  n_col = sm%desc_data%get_local_cols()
  nrow_d = desc_data%get_local_rows()
  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 /= psb_success_) then 
      call psb_errpush(psb_err_alloc_request_,name,i_err=(/3*isz,0,0,0,0/),&
           & a_err='complex(psb_spk_)')
      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 /= psb_success_) then 
      call psb_errpush(psb_err_alloc_request_,name,i_err=(/4*isz,0,0,0,0/),&
           & a_err='complex(psb_spk_)')
      goto 9999      
    end if
  else 
    allocate(ww(isz),tx(isz),ty(isz),&
         &aux(4*isz),stat=info)
    if (info /= psb_success_) then 
      call psb_errpush(psb_err_alloc_request_,name,i_err=(/4*isz,0,0,0,0/),&
           & a_err='complex(psb_spk_)')
      goto 9999      
    end if

  endif

  if ((sm%novr == 0).and.(sweeps == 1)) then 
    !
    ! Shortcut: in this case it's just the same
    ! as Block Jacobi.
    !
    call sm%sv%apply(alpha,x,beta,y,desc_data,trans_,aux,info) 

    if (info /= psb_success_) then
      call psb_errpush(psb_err_internal_error_,name,&
           & a_err='Error in sub_aply Jacobi Sweeps = 1')
      goto 9999
    endif

  else 


    tx(1:nrow_d)     = x(1:nrow_d) 
    tx(nrow_d+1:isz) = czero


    if (sweeps == 1) then 

      select case(trans_)
      case('N')
        !
        ! Get the overlap entries of tx (tx == x)
        ! 
        if (sm%restr == psb_halo_) then 
          call psb_halo(tx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_halo'
            goto 9999
          end if
        else if (sm%restr /= psb_none_) then 
          call psb_errpush(psb_err_internal_error_,name,a_err='Invalid mld_sub_restr_')
          goto 9999
        end if


      case('T','C')
        !
        ! With transpose, we have to do it here
        ! 

        select case (sm%prol) 

        case(psb_none_)
          ! 
          ! Do nothing

        case(psb_sum_) 
          !
          ! The transpose of sum is halo
          !
          call psb_halo(tx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_halo'
            goto 9999
          end if

        case(psb_avg_) 
          !
          ! Tricky one: first we have to scale the overlap entries,
          ! which we can do by assignind mode=0, i.e. no communication
          ! (hence only scaling), then we do the halo
          !
          call psb_ovrl(tx,sm%desc_data,info,&
               & update=psb_avg_,work=aux,mode=0)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_ovrl'
            goto 9999
          end if
          call psb_halo(tx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_halo'
            goto 9999
          end if

        case default
          call psb_errpush(psb_err_internal_error_,name,a_err='Invalid mld_sub_prol_')
          goto 9999
        end select


      case default
        info=psb_err_iarg_invalid_i_
        int_err(1)=6
        ch_err(2:2)=trans
        goto 9999
      end select

      call sm%sv%apply(cone,tx,czero,ty,sm%desc_data,trans_,aux,info) 

      if (info /= psb_success_) then
        call psb_errpush(psb_err_internal_error_,name,&
             & a_err='Error in sub_aply Jacobi Sweeps = 1')
        goto 9999
      endif

      select case(trans_)
      case('N')

        select case (sm%prol) 

        case(psb_none_)
          ! 
          ! Would work anyway, but since it is supposed to do nothing ...
          !        call psb_ovrl(ty,sm%desc_data,info,&
          !             & update=sm%prol,work=aux)


        case(psb_sum_,psb_avg_) 
          !
          ! Update the overlap of ty
          !
          call psb_ovrl(ty,sm%desc_data,info,&
               & update=sm%prol,work=aux)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_ovrl'
            goto 9999
          end if

        case default
          call psb_errpush(psb_err_internal_error_,name,a_err='Invalid mld_sub_prol_')
          goto 9999
        end select

      case('T','C')
        !
        ! With transpose, we have to do it here
        ! 
        if (sm%restr == psb_halo_) then 
          call psb_ovrl(ty,sm%desc_data,info,&
               & update=psb_sum_,work=aux)
          if(info /= psb_success_) then
            info=psb_err_from_subroutine_
            ch_err='psb_ovrl'
            goto 9999
          end if
        else if (sm%restr /= psb_none_) then 
          call psb_errpush(psb_err_internal_error_,name,a_err='Invalid mld_sub_restr_')
          goto 9999
        end if

      case default
        info=psb_err_iarg_invalid_i_
        int_err(1)=6
        ch_err(2:2)=trans
        goto 9999
      end select



    else if (sweeps  > 1) then 

      !
      !
      ! Apply prec%iprcparm(mld_smoother_sweeps_) sweeps of a block-Jacobi solver
      ! to compute an approximate solution of a linear system.
      !
      !
      ty = czero
      do i=1, sweeps
        select case(trans_)
        case('N')
          !
          ! Get the overlap entries of tx (tx == x)
          ! 
          if (sm%restr == psb_halo_) then 
            call psb_halo(tx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_halo'
              goto 9999
            end if
          else if (sm%restr /= psb_none_) then 
            call psb_errpush(psb_err_internal_error_,name,a_err='Invalid mld_sub_restr_')
            goto 9999
          end if


        case('T','C')
          !
          ! With transpose, we have to do it here
          ! 

          select case (sm%prol) 

          case(psb_none_)
            ! 
            ! Do nothing

          case(psb_sum_) 
            !
            ! The transpose of sum is halo
            !
            call psb_halo(tx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_halo'
              goto 9999
            end if

          case(psb_avg_) 
            !
            ! Tricky one: first we have to scale the overlap entries,
            ! which we can do by assignind mode=0, i.e. no communication
            ! (hence only scaling), then we do the halo
            !
            call psb_ovrl(tx,sm%desc_data,info,&
                 & update=psb_avg_,work=aux,mode=0)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_ovrl'
              goto 9999
            end if
            call psb_halo(tx,sm%desc_data,info,work=aux,data=psb_comm_ext_)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_halo'
              goto 9999
            end if

          case default
            call psb_errpush(psb_err_internal_error_,name,a_err='Invalid mld_sub_prol_')
            goto 9999
          end select


        case default
          info=psb_err_iarg_invalid_i_
          int_err(1)=6
          ch_err(2:2)=trans
          goto 9999
        end select
        !
        ! Compute Y(j+1) = D^(-1)*(X-ND*Y(j)), where D and ND are the
        ! block diagonal part and the remaining part of the local matrix
        ! and Y(j) is the approximate solution at sweep j.
        !
        ww(1:n_row) = tx(1:n_row)
        call psb_spmm(-cone,sm%nd,ty,cone,ww,sm%desc_data,info,work=aux,trans=trans_)

        if (info /= psb_success_) exit

        call sm%sv%apply(cone,ww,czero,ty,sm%desc_data,trans_,aux,info) 

        if (info /= psb_success_) exit


        select case(trans_)
        case('N')

          select case (sm%prol) 

          case(psb_none_)
            ! 
            ! Would work anyway, but since it is supposed to do nothing ...
            !        call psb_ovrl(ty,sm%desc_data,info,&
            !             & update=sm%prol,work=aux)


          case(psb_sum_,psb_avg_) 
            !
            ! Update the overlap of ty
            !
            call psb_ovrl(ty,sm%desc_data,info,&
                 & update=sm%prol,work=aux)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_ovrl'
              goto 9999
            end if

          case default
            call psb_errpush(psb_err_internal_error_,name,a_err='Invalid mld_sub_prol_')
            goto 9999
          end select

        case('T','C')
          !
          ! With transpose, we have to do it here
          ! 
          if (sm%restr == psb_halo_) then 
            call psb_ovrl(ty,sm%desc_data,info,&
                 & update=psb_sum_,work=aux)
            if(info /= psb_success_) then
              info=psb_err_from_subroutine_
              ch_err='psb_ovrl'
              goto 9999
            end if
          else if (sm%restr /= psb_none_) then 
            call psb_errpush(psb_err_internal_error_,name,a_err='Invalid mld_sub_restr_')
            goto 9999
          end if

        case default
          info=psb_err_iarg_invalid_i_
          int_err(1)=6
          ch_err(2:2)=trans
          goto 9999
        end select
      end do

      if (info /= psb_success_) then 
        info=psb_err_internal_error_
        call psb_errpush(info,name,a_err='subsolve with Jacobi sweeps > 1')
        goto 9999      
      end if


    else

      info = psb_err_iarg_neg_
      call psb_errpush(info,name,&
           & i_err=(/2,sweeps,0,0,0/))
      goto 9999


    end if

    !
    ! Compute y = beta*y + alpha*ty (ty == K^(-1)*tx)
    !
    call psb_geaxpby(alpha,ty,beta,y,desc_data,info) 

  end if


  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

  call psb_erractionrestore(err_act)
  return

9999 continue
  call psb_erractionrestore(err_act)
  if (err_act == psb_act_abort_) then
    call psb_error()
    return
  end if
  return

end subroutine mld_c_as_smoother_apply

subroutine mld_c_as_smoother_bld(a,desc_a,sm,upd,info,amold,vmold)
  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_bld
  Implicit None

  ! Arguments
  type(psb_cspmat_type), intent(in), target          :: a
  Type(psb_desc_type), Intent(in)                    :: desc_a 
  class(mld_c_as_smoother_type), intent(inout)       :: sm
  character, intent(in)                              :: upd
  integer, intent(out)                               :: info
  class(psb_c_base_sparse_mat), intent(in), optional :: amold
  class(psb_c_base_vect_type), intent(in), optional  :: vmold

  ! Local variables
  type(psb_cspmat_type) :: blck, atmp
  integer :: n_row,n_col, nrow_a, nhalo, novr, data_, nzeros
  complex(psb_spk_), pointer :: ww(:), aux(:), tx(:),ty(:)
  integer :: ictxt,np,me,i, err_act, debug_unit, debug_level
  character(len=20)  :: name='c_as_smoother_bld', ch_err

  info=psb_success_
  call psb_erractionsave(err_act)
  debug_unit  = psb_get_debug_unit()
  debug_level = psb_get_debug_level()
  ictxt       = desc_a%get_context()
  call psb_info(ictxt, me, np)
  if (debug_level >= psb_debug_outer_) &
       & write(debug_unit,*) me,' ',trim(name),' start'


  novr   = sm%novr
  if (novr < 0) then
    info=psb_err_invalid_ovr_num_
    call psb_errpush(info,name,i_err=(/novr,0,0,0,0,0/))
    goto 9999
  endif

  if ((novr == 0).or.(np == 1)) then 
    if (psb_toupper(upd) == 'F') then 
      call psb_cdcpy(desc_a,sm%desc_data,info)
      If(debug_level >= psb_debug_outer_) &
           & write(debug_unit,*) me,' ',trim(name),&
           & '  done cdcpy'
      if(info /= psb_success_) then
        info=psb_err_from_subroutine_
        ch_err='psb_cdcpy'
        call psb_errpush(info,name,a_err=ch_err)
        goto 9999
      end if
      if (debug_level >= psb_debug_outer_) &
           & write(debug_unit,*) me,' ',trim(name),&
           & 'Early return: P>=3 N_OVR=0'
    endif
    call blck%csall(0,0,info,1)
  else

    If (psb_toupper(upd) == 'F') Then
      !
      ! Build the auxiliary descriptor desc_p%matrix_data(psb_n_row_).
      ! This is done by psb_cdbldext (interface to psb_cdovr), which is
      ! independent of CSR, and has been placed in the tools directory
      ! of PSBLAS, instead of the mlprec directory of MLD2P4, because it
      ! might be used independently of the AS preconditioner, to build
      ! a descriptor for an extended stencil in a PDE solver. 
      !
      call psb_cdbldext(a,desc_a,novr,sm%desc_data,info,extype=psb_ovt_asov_)
      if(debug_level >= psb_debug_outer_) &
           & write(debug_unit,*) me,' ',trim(name),&
           & ' From cdbldext _:',sm%desc_data%get_local_rows(),&
           & sm%desc_data%get_local_cols()

      if (info /= psb_success_) then
        info=psb_err_from_subroutine_
        ch_err='psb_cdbldext'
        call psb_errpush(info,name,a_err=ch_err)
        goto 9999
      end if
    Endif

    if (debug_level >= psb_debug_outer_) &
         & write(debug_unit,*) me,' ',trim(name),&
         & 'Before sphalo '

    !
    ! Retrieve the remote sparse matrix rows required for the AS extended
    ! matrix
    data_ = psb_comm_ext_
    Call psb_sphalo(a,sm%desc_data,blck,info,data=data_,rowscale=.true.)

    if (info /= psb_success_) then
      info=psb_err_from_subroutine_
      ch_err='psb_sphalo'
      call psb_errpush(info,name,a_err=ch_err)
      goto 9999
    end if

    if (debug_level >=psb_debug_outer_) &
         & write(debug_unit,*) me,' ',trim(name),&
         & 'After psb_sphalo ',&
         & blck%get_nrows(), blck%get_nzeros()

  End if
  if (info == psb_success_) &
       & call sm%sv%build(a,sm%desc_data,upd,info,&
       &  blck,amold=amold,vmold=vmold)

  nrow_a = a%get_nrows()
  n_row  = sm%desc_data%get_local_rows()
  n_col  = sm%desc_data%get_local_cols()

  if (info == psb_success_) call a%csclip(sm%nd,info,&
       & jmin=nrow_a+1,rscale=.false.,cscale=.false.)
  if (info == psb_success_) call blck%csclip(atmp,info,&
       & jmin=nrow_a+1,rscale=.false.,cscale=.false.)
  if (info == psb_success_) call psb_rwextd(n_row,sm%nd,info,b=atmp) 

  if (info == psb_success_) then 
    if (present(amold)) then 
      call sm%nd%cscnv(info,&
           & mold=amold,dupl=psb_dupl_add_)
    else
      call sm%nd%cscnv(info,&
           & type='csr',dupl=psb_dupl_add_)
    end if
  end if
  if (info /= psb_success_) then
    call psb_errpush(psb_err_from_subroutine_,name,a_err='clip & psb_spcnv csr 4')
    goto 9999
  end if
  nzeros = sm%nd%get_nzeros()
!!$    write(0,*) me,' ND nzeors ',nzeros
  call psb_sum(ictxt,nzeros)
  sm%nd_nnz_tot = nzeros

  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 == psb_act_abort_) then
    call psb_error()
    return
  end if
  return
end subroutine mld_c_as_smoother_bld


subroutine mld_c_as_smoother_seti(sm,what,val,info)
  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_seti
  Implicit None

  ! Arguments
  class(mld_c_as_smoother_type), intent(inout) :: sm 
  integer, intent(in)                    :: what 
  integer, intent(in)                    :: val
  integer, intent(out)                   :: info
  Integer :: err_act
  character(len=20)  :: name='c_as_smoother_seti'

  info = psb_success_
  call psb_erractionsave(err_act)

  select case(what) 
!!$    case(mld_smoother_sweeps_) 
!!$      sm%sweeps = val
  case(mld_sub_ovr_) 
    sm%novr   = val
  case(mld_sub_restr_) 
    sm%restr  = val
  case(mld_sub_prol_) 
    sm%prol   = val
  case default
    if (allocated(sm%sv)) then 
      call sm%sv%set(what,val,info)
    end if
  end select

  call psb_erractionrestore(err_act)
  return

9999 continue
  call psb_erractionrestore(err_act)
  if (err_act == psb_act_abort_) then
    call psb_error()
    return
  end if
  return
end subroutine mld_c_as_smoother_seti

subroutine mld_c_as_smoother_setc(sm,what,val,info)
  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_setc
  Implicit None
  ! Arguments
  class(mld_c_as_smoother_type), intent(inout) :: sm
  integer, intent(in)                    :: what 
  character(len=*), intent(in)           :: val
  integer, intent(out)                   :: info
  Integer :: err_act, ival
  character(len=20)  :: name='c_as_smoother_setc'

  info = psb_success_
  call psb_erractionsave(err_act)


  call mld_stringval(val,ival,info)
  if (info == psb_success_) call sm%set(what,ival,info)
  if (info /= psb_success_) then
    info = psb_err_from_subroutine_
    call psb_errpush(info, name)
    goto 9999
  end if

  call psb_erractionrestore(err_act)
  return

9999 continue
  call psb_erractionrestore(err_act)
  if (err_act == psb_act_abort_) then
    call psb_error()
    return
  end if
  return
end subroutine mld_c_as_smoother_setc

subroutine mld_c_as_smoother_setr(sm,what,val,info)
  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_setr
  Implicit None
  ! Arguments
  class(mld_c_as_smoother_type), intent(inout) :: sm 
  integer, intent(in)                    :: what 
  real(psb_spk_), intent(in)             :: val
  integer, intent(out)                   :: info
  Integer :: err_act
  character(len=20)  :: name='c_as_smoother_setr'

  call psb_erractionsave(err_act)
  info = psb_success_


  if (allocated(sm%sv)) then 
    call sm%sv%set(what,val,info)
  else
!!$      write(0,*) trim(name),' Missing component, not setting!'
!!$      info = 1121
  end if

  call psb_erractionrestore(err_act)
  return

9999 continue
  call psb_erractionrestore(err_act)
  if (err_act == psb_act_abort_) then
    call psb_error()
    return
  end if
  return
end subroutine mld_c_as_smoother_setr

subroutine mld_c_as_smoother_free(sm,info)
  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_free
  Implicit None
  ! Arguments
  class(mld_c_as_smoother_type), intent(inout) :: sm
  integer, intent(out)                       :: info
  Integer :: err_act
  character(len=20)  :: name='c_as_smoother_free'

  call psb_erractionsave(err_act)
  info = psb_success_



  if (allocated(sm%sv)) then 
    call sm%sv%free(info)
    if (info == psb_success_) deallocate(sm%sv,stat=info)
    if (info /= psb_success_) then 
      info = psb_err_alloc_dealloc_
      call psb_errpush(info,name)
      goto 9999 
    end if
  end if
  call sm%nd%free()

  call psb_erractionrestore(err_act)
  return

9999 continue
  call psb_erractionrestore(err_act)
  if (err_act == psb_act_abort_) then
    call psb_error()
    return
  end if
  return
end subroutine mld_c_as_smoother_free

subroutine mld_c_as_smoother_dmp(sm,ictxt,level,info,prefix,head,smoother,solver)
  use psb_base_mod
  use mld_c_as_smoother, mld_protect_nam => mld_c_as_smoother_dmp
  implicit none 
  class(mld_c_as_smoother_type), intent(in) :: sm
  integer, intent(in)              :: ictxt,level
  integer, intent(out)             :: info
  character(len=*), intent(in), optional :: prefix, head
  logical, optional, intent(in)    :: smoother, solver
  integer :: i, j, il1, iln, lname, lev
  integer :: icontxt,iam, np
  character(len=80)  :: prefix_
  character(len=120) :: fname ! len should be at least 20 more than
  logical :: smoother_
  !  len of prefix_ 

  info = 0

  if (present(prefix)) then 
    prefix_ = trim(prefix(1:min(len(prefix),len(prefix_))))
  else
    prefix_ = "dump_smth_c"
  end if

  call psb_info(ictxt,iam,np)

  if (present(smoother)) then 
    smoother_ = smoother
  else
    smoother_ = .false. 
  end if
  lname = len_trim(prefix_)
  fname = trim(prefix_)
  write(fname(lname+1:lname+5),'(a,i3.3)') '_p',iam
  lname = lname + 5

  if (smoother_) then 
    write(fname(lname+1:),'(a,i3.3,a)')'_l',level,'_nd.mtx'
    if (sm%nd%is_asb()) &
         & call sm%nd%print(fname,head=head)
  end if
  ! At base level do nothing for the smoother
  if (allocated(sm%sv)) &
       & call sm%sv%dump(ictxt,level,info,solver=solver,prefix=prefix)

end subroutine mld_c_as_smoother_dmp