http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47844
--- Comment #7 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-10-05 15:04:02 UTC --- (In reply to comment #6) > We could fix this in 4.7 by adding a sm field to array descriptors. > If we added the sm field after the dimension array, we would not > damage the exiting API. I think that one can create cases, where it fails - for instance when combining a GCC 4.7 compiled procedure with a GCC 4.6 compiled procedure. For instance some combination of gcc_4_6_compiled() type(t), pointer :: A(:) call assign_in_gcc_4_7_compiled (A) might fail, if one accesses "a.sm" in "assign_in_gcc_4_7_compiled". If we can rule out that such issues occur for currently working code, we can do so. You also have a small ABI issue with allocatable coarrays: In GCC 4.6 or 4.7, using -fcoarray=single, one has for integer, allocatable :: A(:)[:] allocate (A(1)[3:*]) an extra dimension triplet for coarrays: a.dim[0].lbound = 1; a.dim[0].ubound = 1; a.dim[0].stride = 1; a.dim[1].lbound = 3; Given that coarrays are not yet widely used and that coarrays in 4.6 had some issues, it might be a smaller problem.