2008-04-15  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-sccvn.h (vn_reference_lookup): Adjust prototype.
	* tree-ssa-sccvn.c (vn_reference_lookup): New parameter maywalk.
	(visit_reference_op_load): Do walk vuse-vdef chains on
	vn_reference_lookup.
	(visit_reference_op_store): But do not here.
	* tree-vn.c (vn_lookup): Do not walk vuse-vdef chains on
	vn_reference_lookup.
	(vn_lookup_with_vuses): But do so here.

From-SVN: r134314