http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49330
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-06-09 10:38:37 UTC --- find_base_value/find_base_term seem to be overly optimistic, prefer to return something over being conservative. E.g. if both operands of PLUS or MINUS return non-NULL find_base_term, we just return the first one, etc. It doesn't differentiate between "certainly not based on something" - e.g. CONST_INT, regs only initialized by them and only incremented by constant etc. would be such and unknown. While the overly optimistic implementation might be useful in some cases, at least for base_alias_check it is inappropriate.
