program vectoacc
    use psb_base_mod
    use psb_oacc_mod
    implicit none
  
    type(psb_d_vect_oacc) :: v3, v4, v5
    integer(psb_ipk_) :: info, n, i
    real(psb_dpk_) :: alpha, beta, result
    double precision, external :: etime
  
    real(psb_dpk_) :: dot_host, dot_dev, t_host, t_dev, t_alloc_host, t_alloc_dev, t_calc_host, t_calc_dev
    double precision :: time_start, time_end
    integer(psb_ipk_), parameter :: ntests=80, ngpu=20
  
    write(*, *) 'Test of the vector operations with OpenACC'
  
    write(*, *) 'Enter the size of the vectors'
    read(*, *) n
    alpha = 2.0
    beta = 0.5
  
    time_start = etime()
    call v3%all(n, info)
    call v4%all(n, info)
    call v5%all(n, info)
    time_end = etime()
    t_alloc_host = time_end - time_start
    write(*, *) 'Allocation time on host: ', t_alloc_host, ' sec'
  
    do i = 1, n
        v3%v(i) = real(i, psb_dpk_)
        v4%v(i) = real(n - i, psb_dpk_)
    end do
  
    call v3%set_dev()
    call v4%set_dev()
  
    call v3%scal(alpha)
    call v3%sync()
  
    do i = 1, n
        if (v3%v(i) /= alpha * real(i, psb_dpk_)) then
            write(*, *) 'Scal error : index', i
        end if
    end do
    write(*, *) 'Scal test passed'
  
    result = v3%dot_v(n, v4)
    call v3%sync()
    call v4%sync()
    if (result /= sum(v3%v * v4%v)) then
        write(*, *) 'Dot_v error,  expected result:', sum(v3%v * v4%v), 'instead of :', result
    end if
    write(*, *) 'Dot_v test passed'
  
    result = v3%nrm2(n)
    call v3%sync()
    if (result /= sqrt(sum(v3%v ** 2))) then
        write(*, *) 'nrm2 error, expected result:', sqrt(sum(v3%v ** 2)), 'instead of :', result
    end if
    write(*, *) 'nrm2 test passed'
  
    call v3%set_host()
    call v4%set_host()
  
    time_start = etime()
    do i = 1, ntests
        dot_host = sum(v3%v * v4%v)
    end do
    time_end = etime()
    t_calc_host = (time_end - time_start) / real(ntests)
    write(*, *) 'Host calculation time: ', t_calc_host, ' sec'
  
    call v3%set_dev()
    call v4%set_dev()
  
    time_start = etime()
    call v3%sync_space()
    call v4%sync_space()
    time_end = etime()
    t_alloc_dev = time_end - time_start
    write(*, *) 'Allocation time on device: ', t_alloc_dev, ' sec'
  
    time_start = etime()
    do i = 1, ntests
        dot_dev = v3%dot_v(n, v4)
    end do
    !$acc wait
    time_end = etime()
    t_calc_dev = (time_end - time_start) / real(ntests)
    write(*, *) 'Device calculation time: ', t_calc_dev, ' sec'

  
    call v3%free(info)
    call v4%free(info)
    call v5%free(info)
  
end program vectoacc