------- Comment #4 from kargl at gcc dot gnu dot org 2009-06-15 18:44 ------- (In reply to comment #3) > This is not darwin-specific, I also see it happening on x86_64-linux. > > And what's more, the output changes between -m32 and -m64.
The code is invalid Fortran, so gfortran is not required to give any sensible output. > $ cat u.f90 > integer(8), parameter :: l = z'5fe6eb3be0000000' > integer, parameter :: ni = 3 > integer :: i, j, n > integer(8) :: k > real(8) :: a, b, e, m, s > equivalence (b, k) > a = 1.0d0 > e = epsilon(1.0)/2.0d0**4 > m = 0.0d0 > s = 0.0d0 > n = 0 > do > n = n + 1 > b = a When you do the assignment to b, k is/becomes undefined. > k = l - ishft(k, -1_8) When you do the assignment to k, b becomes undefined. Not to mention, that the RHS uses k, which is undefined. See Section 14.7.6 (1) and (9). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36241
