DownloadOldWindow_DGModel2D_t Subroutine

  1. SELF_DGModel2D_t.f90
  2. SELF_DGModel2D_t
  3. DownloadOldWindow_DGModel2D_t

public subroutine DownloadOldWindow_DGModel2D_t(this, wFirst, wLast, uWin)

Copy the migrated window into a host array, for the SELF_AMR_MIGRATE_VERIFY diagnostic. Diagnostic-only and off the default path: on a GPU build the override is a device-to-host transfer of the whole window, which is exactly the traffic the device path exists to avoid.

The comparison this feeds is BITWISE, and must stay that way. Migration is pure data movement - host and device copies, MPI byte transfers - so no arithmetic touches these values and exactness is available. That is unlike the transfer APPLY, which agrees between host and device only to round-off because the device compiler contracts its multiply-accumulates into FMAs. The two are checked by different switches for that reason.

Arguments

TypeIntentOptionalAttributesName
class(DGModel2D_t), intent(in) :: this
integer, intent(in) :: wFirst
integer, intent(in) :: wLast
real(kind=prec), intent(out), target, contiguous:: uWin(:,:,:,:)

(Np,Np,nWinElem,nvar)

Called by

proc~~downloadoldwindow_dgmodel2d_t~~CalledByGraph proc~downloadoldwindow_dgmodel2d_t DownloadOldWindow_DGModel2D_t proc~adapt_amrcontroller2d Adapt_AMRController2D proc~adapt_amrcontroller2d->proc~downloadoldwindow_dgmodel2d_t

Contents

Source Code

DownloadOldWindow_DGModel2D_t

Source Code

  subroutine DownloadOldWindow_DGModel2D_t(this,wFirst,wLast,uWin)
    !! Copy the migrated window into a host array, for the SELF_AMR_MIGRATE_VERIFY diagnostic.
    !! Diagnostic-only and off the default path: on a GPU build the override is a device-to-host
    !! transfer of the whole window, which is exactly the traffic the device path exists to avoid.
    !!
    !! The comparison this feeds is BITWISE, and must stay that way. Migration is pure data
    !! movement - host and device copies, MPI byte transfers - so no arithmetic touches these
    !! values and exactness is available. That is unlike the transfer APPLY, which agrees between
    !! host and device only to round-off because the device compiler contracts its
    !! multiply-accumulates into FMAs. The two are checked by different switches for that reason.
    implicit none
    class(DGModel2D_t),intent(in) :: this
    integer,intent(in) :: wFirst
    integer,intent(in) :: wLast
    ! target: the GPU override takes c_loc of this to download the window in one memcpy.
    real(prec),intent(out),target,contiguous :: uWin(:,:,:,:) !! (Np,Np,nWinElem,nvar)
    ! Local
    integer :: Np,perElem,nWinElem,i,j,e,iv,p,off

    nWinElem = max(wLast-wFirst+1,0)
    if(nWinElem == 0) return

    Np = this%solution%interp%N+1
    perElem = Np*Np
    if(size(uWin,3) /= nWinElem .or. size(uWin,4) /= this%nvar) then
      print*,__FILE__,':',__LINE__, &
        ' : Error : DownloadOldWindow given a buffer that does not match the window.'
      stop 1
    endif
    if(this%winStageN /= nWinElem .or. this%winStageFirst /= wFirst) then
      print*,__FILE__,':',__LINE__, &
        ' : Error : DownloadOldWindow called without a matching migrated window.'
      stop 1
    endif

    do iv = 1,this%nvar
      do e = 1,nWinElem
        off = perElem*((e-1)+nWinElem*(iv-1))
        p = 0
        do j = 1,Np
          do i = 1,Np
            p = p+1
            uWin(i,j,e,iv) = this%winStage(off+p)
          enddo
        enddo
      enddo
    enddo

  endsubroutine DownloadOldWindow_DGModel2D_t