2009-06-30  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-dce.c (mark_all_reaching_defs_necessary_1): Always
	continue walking.
	(propagate_necessity): Do not mark reaching defs of stores
	as necessary.

	* gcc.dg/tree-ssa/ssa-dce-6.c: New testcase.

From-SVN: r149103