[Bug fortran/49103] [4.6/4.7 Regression] local variables exchange values / wrong code with -O3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49103

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-31 
11:54:23 UTC ---
Smaller, self-contained testcase:

! PR fortran/49103
! { dg-do run }
  integer :: a(2), b(2), i, j
  open (10, status='scratch')
  do j = 1, 2
  a = (/ 0, 0 /)
  b = (/ 1, 1 /)
  do i = 1, 2
    write (10, *) a
    write (10, *) b
  end do
  end do
  rewind (10)
  do i = 0, 7
    read (10, *) a
    if (any (a .ne. mod (i, 2))) call abort
  end do
  close (10)
end