http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49235
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-31 09:34:04 UTC --- get_address_description only does that if TMR_INDEX2 is present: addr->symbol = NULL_TREE; if (TMR_INDEX2 (op)) { gcc_assert (integer_zerop (TMR_BASE (op))); addr->base = TMR_INDEX2 (op); } else addr->base = TMR_BASE (op); In this case TMR_BASE (op) is (void *) 0 and TMR_OFFSET is INTEGER_CST, the rest is all NULL.