2008-02-29  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-pre.c (get_sccvn_value): Create missing VNs via
	vn_lookup_or_add.
	* tree-ssa-sccnv.c (visit_reference_op_store): Use the rhs
	value for comparing for a store match.
	(simplify_unary_expression): Do nothing for SSA_NAMEs.
	(try_to_simplify): Do not do a full-blown reference lookup.

From-SVN: r132768