amg4psblas/amgprec/impl/smoother/amg_d_poly_smoother_apply_vect.f90

!
!
!                             AMG4PSBLAS version 1.0
!    Algebraic Multigrid Package
!               based on PSBLAS (Parallel Sparse BLAS version 3.7)
!
!    (C) Copyright 2021
!
!        Salvatore Filippone
!        Pasqua D'Ambra
!        Daniela di Serafino
!
!    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 AMG4PSBLAS 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 AMG4PSBLAS GROUP OR ITS CONTRIBUTORS
!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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!    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 amg_d_poly_smoother_apply_vect(alpha,sm,x,beta,y,desc_data,trans,&
     & sweeps,work,wv,info,init,initu)

  use psb_base_mod
  use amg_d_diag_solver
  use psb_base_krylov_conv_mod, only : log_conv
  use amg_d_poly_smoother, amg_protect_name => amg_d_poly_smoother_apply_vect
  implicit none
  type(psb_desc_type), intent(in)                 :: desc_data
  class(amg_d_poly_smoother_type), intent(inout) :: sm
  type(psb_d_vect_type),intent(inout)           :: x
  type(psb_d_vect_type),intent(inout)           :: y
  real(psb_dpk_),intent(in)                      :: alpha,beta
  character(len=1),intent(in)                     :: trans
  integer(psb_ipk_), intent(in)                   :: sweeps
  real(psb_dpk_),target, intent(inout)           :: work(:)
  type(psb_d_vect_type),intent(inout)           :: wv(:)
  integer(psb_ipk_), intent(out)                  :: info
  character, intent(in), optional                :: init
  type(psb_d_vect_type),intent(inout), optional   :: initu
  !
  integer(psb_ipk_)    :: n_row,n_col
  type(psb_d_vect_type)  :: tx, ty, tz, r
  real(psb_dpk_), pointer :: aux(:)
  type(psb_ctxt_type) :: ctxt
  integer(psb_ipk_)   :: np, me, i, err_act
  character           :: trans_, init_
  real(psb_dpk_)      :: res, resdenum
  real(psb_dpk_)      :: cz, cr
  character(len=20)   :: name='d_poly_smoother_apply_v'

  call psb_erractionsave(err_act)

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


  if (present(init)) then
    init_ = psb_toupper(init)
  else
    init_='Z'
  end if

  trans_ = psb_toupper(trans)
  select case(trans_)
  case('N')
  case('T','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 = desc_data%get_local_rows()
  n_col = desc_data%get_local_cols()

  if (4*n_col <= size(work)) then
    aux => work(:)
  else
    allocate(aux(4*n_col),stat=info)
    if (info /= psb_success_) then
      info=psb_err_alloc_request_
      call psb_errpush(info,name,&
           & i_err=(/4*n_col,izero,izero,izero,izero/),&
           & a_err='real(psb_dpk_)')
      goto 9999
    end if
  endif
!!$  if (me == 0) write(0,*) name,' Unimplemented apply_vect '
!!$  info =psb_err_internal_error_
!!$  call psb_errpush(info,&
!!$       & name,a_err='Error in sub_aply Polynomial not implemented')
!!$  goto 9999

  if (size(wv) < 4) then
    info = psb_err_internal_error_
    call psb_errpush(info,name,&
         & a_err='invalid wv size in smoother_apply')
    goto 9999
  end if

  associate(tx => wv(1), ty => wv(2), tz => wv(3), r => wv(4))

    call psb_geaxpby(done,x,dzero,r,desc_data,info)
    call tx%zero()
    call ty%zero()
    call tz%zero()       

    select case(sm%variant)
    case(amg_poly_lottes_)
      !  b == x 
      !  x == tx
      ! 
      do i=1, sm%pdegree
        !   B r_{k-1}
        call sm%sv%apply(done,r,dzero,ty,desc_data,trans_,aux,wv(5:),info,init='Z')
        cz = (2*i*done-3)/(2*i*done+done)
        cr = (8*i*done-4)/((2*i*done+done)*sm%rho_ba)
        ! z_k =  cz z_{k-1} + cr ty = cz z_{k-1} + cr Br_{k-1}
        call psb_geaxpby(cr,ty,cz,tz,desc_data,info)
        ! r_k =    b-Ax_k  = x -A tx
        call psb_geaxpby(done,tz,done,tx,desc_data,info)
        if (.false.) then
          call psb_geaxpby(done,x,dzero,r,desc_data,info)
          call psb_spmm(-done,sm%pa,tx,done,r,desc_data,info,work=aux,trans=trans_)
        else
          call psb_spmm(-done,sm%pa,tz,done,r,desc_data,info,work=aux,trans=trans_)
        end if
!!$        res  = psb_genrm2(r,desc_data,info)
!!$        write(0,*) 'Polynomial smoother ',i,res
        ! x_k =  x_{k-1} + z_k
      end do

    case(amg_poly_lottes_beta_)

      !  b == x 
      !  x == tx
      ! 
      do i=1, sm%pdegree
        !   B r_{k-1}
        call sm%sv%apply(done,r,dzero,ty,desc_data,trans_,aux,wv(5:),info,init='Z')
        cz = (2*i*done-3)/(2*i*done+done)
        cr = (8*i*done-4)/((2*i*done+done)*sm%rho_ba)
        ! z_k =  cz z_{k-1} + cr ty = cz z_{k-1} + cr Br_{k-1}
        call psb_geaxpby(cr,ty,cz,tz,desc_data,info)
        ! r_k =    b-Ax_k  = x -A tx
        call psb_geaxpby(sm%poly_beta(i),tz,done,tx,desc_data,info)
        if (.false.) then
          call psb_geaxpby(done,x,dzero,r,desc_data,info)
          call psb_spmm(-done,sm%pa,tx,done,r,desc_data,info,work=aux,trans=trans_)
        else
          call psb_spmm(-done,sm%pa,tz,done,r,desc_data,info,work=aux,trans=trans_)
        end if
!!$        res  = psb_genrm2(r,desc_data,info)
!!$        write(0,*) 'Polynomial smoother ',i,res
        ! x_k =  x_{k-1} + z_k
      end do

      
    case default
      info=psb_err_internal_error_
      call psb_errpush(info,name,&
           & a_err='wrong polynomial variant')
      goto 9999
    end select
    
    if (info == psb_success_) call psb_geaxpby(alpha,tx,beta,y,desc_data,info)

    if (info /= psb_success_) then
      info=psb_err_internal_error_
      call psb_errpush(info,name,&
           & a_err='polynomial smoother')
      goto 9999
    end if
  end associate




!!$  if ((.not.sm%sv%is_iterative()).and.((sweeps == 1).or.(sm%nd_nnz_tot==0))) then
!!$    !  if .not.sv%is_iterative, there's no need to pass init
!!$    call sm%sv%apply(alpha,x,beta,y,desc_data,trans_,aux,wv,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 if (sweeps >= 0) then
!!$    select type (smsv => sm%sv)
!!$    class is (amg_d_diag_solver_type)
!!$      !
!!$      ! This means we are dealing with a pure Jacobi smoother/solver.
!!$      !
!!$      associate(tx => wv(1), ty => wv(2))
!!$        select case (init_)
!!$        case('Z')
!!$
!!$          call sm%sv%apply(done,x,dzero,ty,desc_data,trans_,aux,wv(3:),info,init='Z')
!!$
!!$        case('Y')
!!$          call psb_geaxpby(done,x,dzero,tx,desc_data,info)
!!$          call psb_geaxpby(done,y,dzero,ty,desc_data,info)
!!$          call psb_spmm(-done,sm%pa,ty,done,tx,desc_data,info,work=aux,trans=trans_)
!!$          call sm%sv%apply(done,tx,dzero,ty,desc_data,trans_,aux,wv(3:),info,init='Y')
!!$
!!$        case('U')
!!$          if (.not.present(initu)) then
!!$            call psb_errpush(psb_err_internal_error_,name,&
!!$                 & a_err='missing initu to smoother_apply')
!!$            goto 9999
!!$          end if
!!$          call psb_geaxpby(done,x,dzero,tx,desc_data,info)
!!$          call psb_geaxpby(done,initu,dzero,ty,desc_data,info)
!!$          call psb_spmm(-done,sm%pa,ty,done,tx,desc_data,info,work=aux,trans=trans_)
!!$          call sm%sv%apply(done,tx,dzero,ty,desc_data,trans_,aux,wv(3:),info,init='Y')
!!$
!!$        case default
!!$          call psb_errpush(psb_err_internal_error_,name,&
!!$               & a_err='wrong  init to smoother_apply')
!!$          goto 9999
!!$        end select
!!$
!!$        do i=1, sweeps-1
!!$          !
!!$          ! Compute Y(j+1) =  Y(j)+ D^(-1)*(X-A*Y(j)),
!!$          !  where is the diagonal and  A the matrix.
!!$          !
!!$          call psb_geaxpby(done,x,dzero,tx,desc_data,info)
!!$          call psb_spmm(-done,sm%pa,ty,done,tx,desc_data,info,work=aux,trans=trans_)
!!$
!!$          if (info /= psb_success_) exit
!!$
!!$          call sm%sv%apply(done,tx,done,ty,desc_data,trans_,aux,wv(3:),info,init='Y')
!!$
!!$          if (info /= psb_success_) exit
!!$
!!$          if ( sm%checkres.and.(mod(i,sm%checkiter) == 0) ) then
!!$            call psb_geaxpby(done,x,dzero,r,r,desc_data,info)
!!$            call psb_spmm(-done,sm%pa,ty,done,r,desc_data,info)
!!$            res  = psb_genrm2(r,desc_data,info)
!!$            if( sm%printres ) then
!!$              call log_conv("BJAC",me,i,sm%printiter,res,resdenum,sm%tol)
!!$            end if
!!$            if ( res < sm%tol*resdenum ) then
!!$              if( (sm%printres).and.(mod(sm%printiter,sm%checkiter)/=0) ) &
!!$               & call log_conv("BJAC",me,i,1,res,resdenum,sm%tol)
!!$              exit
!!$            end if
!!$          end if
!!$
!!$        end do
!!$
!!$
!!$        if (info == psb_success_) call psb_geaxpby(alpha,ty,beta,y,desc_data,info)
!!$
!!$        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
!!$
!!$
!!$      end associate
!!$
!!$    class default
!!$      !
!!$      !
!!$      ! Apply multiple sweeps of a block-Jacobi solver
!!$      ! to compute an approximate solution of a linear system.
!!$      !
!!$      !
!!$      if (size(wv) < 2) then
!!$        info = psb_err_internal_error_
!!$        call psb_errpush(info,name,&
!!$             & a_err='invalid wv size in smoother_apply')
!!$        goto 9999
!!$      end if
!!$      associate(tx => wv(1), ty => wv(2))
!!$
!!$        !
!!$        !  Unroll  the first iteration and fold it inside SELECT CASE
!!$        !  this will save one AXPBY and one SPMM when INIT=Z, and will be
!!$        !  significant when sweeps=1 (a common case)
!!$        !
!!$        select case (init_)
!!$        case('Z')
!!$
!!$          call sm%sv%apply(done,x,dzero,ty,desc_data,trans_,aux,wv(3:),info,init='Z')
!!$
!!$        case('Y')
!!$          call psb_geaxpby(done,x,dzero,tx,desc_data,info)
!!$          call psb_geaxpby(done,y,dzero,ty,desc_data,info)
!!$          call psb_spmm(-done,sm%nd,ty,done,tx,desc_data,info,work=aux,trans=trans_)
!!$          call sm%sv%apply(done,tx,dzero,ty,desc_data,trans_,aux,wv(3:),info,init='Y')
!!$
!!$        case('U')
!!$          if (.not.present(initu)) then
!!$            call psb_errpush(psb_err_internal_error_,name,&
!!$                 & a_err='missing initu to smoother_apply')
!!$            goto 9999
!!$          end if
!!$          call psb_geaxpby(done,x,dzero,tx,desc_data,info)
!!$          call psb_geaxpby(done,initu,dzero,ty,desc_data,info)
!!$          call psb_spmm(-done,sm%nd,ty,done,tx,desc_data,info,work=aux,trans=trans_)
!!$          call sm%sv%apply(done,tx,dzero,ty,desc_data,trans_,aux,wv(3:),info,init='Y')
!!$
!!$        case default
!!$          call psb_errpush(psb_err_internal_error_,name,&
!!$               & a_err='wrong  init to smoother_apply')
!!$          goto 9999
!!$        end select
!!$
!!$        do i=1, sweeps-1
!!$          !
!!$          ! 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(done,x,dzero,tx,desc_data,info)
!!$          call psb_spmm(-done,sm%nd,ty,done,tx,desc_data,info,work=aux,trans=trans_)
!!$
!!$          if (info /= psb_success_) exit
!!$
!!$          call sm%sv%apply(done,tx,dzero,ty,desc_data,trans_,aux,wv(3:),info,init='Y')
!!$
!!$          if (info /= psb_success_) exit
!!$
!!$          if ( sm%checkres.and.(mod(i,sm%checkiter) == 0) ) then
!!$            call psb_geaxpby(done,x,dzero,r,r,desc_data,info)
!!$            call psb_spmm(-done,sm%pa,ty,done,r,desc_data,info)
!!$            res  = psb_genrm2(r,desc_data,info)
!!$            if( sm%printres ) then
!!$              call log_conv("BJAC",me,i,sm%printiter,res,resdenum,sm%tol)
!!$            end if
!!$            if (res < sm%tol*resdenum ) then
!!$              if( (sm%printres).and.( mod(sm%printiter,sm%checkiter) /=0 ) ) &
!!$                & call log_conv("BJAC",me,i,1,res,resdenum,sm%tol)
!!$              exit
!!$            end if
!!$          end if
!!$
!!$        end do
!!$
!!$        if (info == psb_success_) call psb_geaxpby(alpha,ty,beta,y,desc_data,info)
!!$
!!$        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
!!$
!!$      end associate
!!$    end select
!!$
!!$  else
!!$
!!$    info = psb_err_iarg_neg_
!!$    call psb_errpush(info,name,&
!!$         & i_err=(/itwo,sweeps,izero,izero,izero/))
!!$    goto 9999
!!$
!!$  endif
!!$
  if (.not.(4*n_col <= size(work))) then
    deallocate(aux)
  endif

!!$  if(sm%checkres) then
!!$    call psb_gefree(r,desc_data,info)
!!$  end if

  call psb_erractionrestore(err_act)
  return

9999 call psb_error_handler(err_act)

  return

end subroutine amg_d_poly_smoother_apply_vect