https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69110
--- Comment #13 from vries at gcc dot gnu.org --- In 4.6, parloops failed to parallelize because in find_data_references_in_stmt we had: ... /* FIXME -- data dependence analysis does not work correctly for objects with invariant addresses in loop nests. Let us fail here until the problem is fixed. */ if (dr_address_invariant_p (dr) && nest) { free_data_ref (dr); if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "\tFAILED as dr address is invariant\n"); ret = false; break; } ... That FIXME was removed in the fix for PR46787, at r175704.