2012-05-23  Richard Guenther  <rguenther@suse.de>

	* tree-dfa.c (add_referenced_var_1): Do not add global vars.
	* tree-ssa-live.c (mark_all_vars_used_1): Handle global vars
	via the global_unused_vars bitmap.
	(remove_unused_locals): Handle global vars in local-decls via
	a global_unused_vars bitmap instead of the used flag in the
	var annotation.  Simplify global variable handling and removal.

	* gcc.dg/torture/pr39074-2.c: Adjust.
	* gcc.dg/torture/pr39074.c: Likewise.
	* gcc.dg/torture/pta-structcopy-1.c: Likewise.
	* gcc.dg/tree-ssa/alias-19.c: Likewise.

From-SVN: r187800