1subroutine foo(a, b, x, n)
2  real(kind=8) :: a(n), b(n), tmp
3  logical(kind=1) :: x
4  integer(kind=4) :: i, n
5  do i = 1, n
6     if (x) then
7        a(i) = b(i)
8     end if
9     b(i) = b(i) + 10
10  end do
11end subroutine
12