2010-08-09  Bingfeng Mei  <bmei@broadcom.com>

	* ddg.c (walk_mems_2): Moved from alias.c, use may_alias_p instead of
	alias_sets_conflict_p.
	(walk_mems_1): Moved from alias.c.
	(insns_may_alias_p): New function, originally insn_alias_sets_conflict_p
	in alias.c. 
        (add_inter_loop_mem_dep): Use insns_may_alias_p now.
        * cse.c (cse_insn): New argument in calling nonoverlapping_memrefs_p.
        * alias.c (walk_mems_2): Moved to ddg.c.
	(walk_mems_1): Ditto.
	(insn_alias_sets_conflict_p): Renamed to insns_may_alias_p and moved
	to ddg.c.
	(nonoverlapping_memrefs_p): Add flag to guard offset-based memory
	disambiguation.
	*(may_alias_p): New function to check whether two memory expression
	may alias or not. Currently used in buidling inter-iteration memory
	dependence.
	*alias.h (nonoverlapping_memrefs_p): New flag as third argument.
	(insn_alias_sets_conflict_p): Removed
	*rtl.h (may_alias_p): New function prototype.

From-SVN: r163037