get_partial_swish Function

  function get_partial_swish(this, upstream_grad) result(output)
    !! Get partial derivative of swish activation
    implicit none
    class(array_type), intent(inout) :: this
    type(array_type), intent(in) :: upstream_grad
    type(array_type) :: output

    type(array_type), pointer :: ptr
    type(array_type), pointer :: exp_term

    exp_term => exp(this%right_operand%val(1,1) * this%left_operand)

    ptr => upstream_grad * exp_term * ( &
         this%right_operand%val(1,1) * this%left_operand + &
         exp_term + 1._real32 &
    ) / ( ( exp_term + 1._real32 )**2._real32 )

    call output%assign_and_deallocate_source(ptr)
  end function get_partial_swish