2013-09-06  Richard Biener  <rguenther@suse.de>

	* basic-block.h (class control_dependences): New.
	* tree-ssa-dce.c (control_dependence_map): Remove.
	(cd): New global.
	(EXECUTE_IF_CONTROL_DEPENDENT): Remove.
	(set_control_dependence_map_bit, clear_control_dependence_bitmap,
	find_pdom, find_control_dependence, find_all_control_dependences):
	Move to cfganal.c.
	(mark_control_dependent_edges_necessary, find_obviously_necessary_stmts,
	propagate_necessity, tree_dce_init, tree_dce_done,
	perform_tree_ssa_dce): Adjust.
	* cfganal.c (set_control_dependence_map_bit,
	clear_control_dependence_bitmap, find_pdom, find_control_dependence,
	find_all_control_dependences): Move from tree-ssa-dce.c and
	implement as methods of control_dependences class.
	(control_dependences::control_dependences): New.
	(control_dependences::~control_dependences): Likewise.
	(control_dependences::get_edges_dependent_on): Likewise.
	(control_dependences::get_edge): Likewise.

From-SVN: r202309