hypre_obj_SetupSolverS Subroutine

    impure subroutine hypre_obj_SetupSolverS(this)
      !> Sets up the hypre solver.
      implicit none
      class(hypre_obj), intent(inout) :: this                                  !! Hypre machinery
      ! Work variables
      integer :: ierr

      select case (this%solver_name)
      case (HYPRE_SOL_S_PCG_NONE)
        ! Create
        call HYPRE_StructPCGCreate(this%comm,this%solver, ierr)
        ! Parameterize
        call HYPRE_StructPCGSetMaxIter(     this%solver, this%MaxIt,   ierr)
        call HYPRE_StructPCGSetTol(         this%solver, this%MaxTol,  ierr)
        call HYPRE_StructPCGSetPrintLevel(  this%solver, 1,            ierr)
        call HYPRE_StructPCGSetLogging(     this%solver, 1,            ierr)
        ! Setup
        call HYPRE_StructPCGSetup(this%solver,this%matrix,this%rhs,this%sol,ierr)

      case(HYPRE_SOL_S_SMG_NONE)
        ! Create
        call HYPRE_StructSMGCreate(this%comm,this%solver,   ierr)
        ! Parameterize
        call HYPRE_StructSMGSetMaxIter(     this%solver, this%MaxIt,   ierr)
        call HYPRE_StructSMGSetTol(         this%solver, this%MaxTol,  ierr)
        call HYPRE_StructSMGSetNumPreRelax( this%solver, 1,            ierr)
        call HYPRE_StructSMGSetNumPostRelax(this%solver, 1,            ierr)
        call HYPRE_StructSMGSetPrintLevel(  this%solver, 1,            ierr)
        call HYPRE_StructSMGSetLogging(     this%solver, 1,            ierr)
        ! Setup
        call HYPRE_StructSMGSetup(this%solver,this%matrix,this%rhs,this%sol,ierr)

      case(HYPRE_SOL_S_PFMG_NONE)
        ! Create
        call HYPRE_StructPFMGCreate(this%comm,this%solver , ierr)
        ! Parameterize
        call HYPRE_StructPFMGSetMaxIter(    this%solver, this%MaxIt,    ierr)
        call HYPRE_StructPFMGSetTol(        this%solver, this%MaxTol,   ierr)
        call HYPRE_StructPFMGSetRelaxType(  this%solver, this%RelaxType,ierr)
        call HYPRE_StructPFMGSetRAPType(    this%solver, 0,             ierr)
        call HYPRE_StructPFMGSetLogging(    this%solver, 1,             ierr)
        call HYPRE_StructPFMGSetPrintLevel( this%solver, 1,             ierr)
        ! Setup
        call HYPRE_StructPFMGSetup(this%solver,this%matrix,this%rhs,this%sol,ierr)
      case default
        call this%parallel%Stop("Unknown HYPRE solver")
      end select

      return
    end subroutine hypre_obj_SetupSolverS