tree-ssa-dce.c (visited_control_parents): New sbitmap to replace BB_VISITED uses.

tree-ssa-dce.c (visited_control_parents): New sbitmap to replace BB_VISITED uses.

	* tree-ssa-dce.c (visited_control_parents): New sbitmap to
	replace BB_VISITED uses.
	(find_obviously_necessary_stmts): Don't clear BB_VISITED.
	(propagate_necessity): Check the bitmap instead of BB_VISITED.
	(tree_dce_done): Free visited_control_parents.
	(perform_tree_ssa_dce): Allocate and clear it.
	* tree-ssa-pre.c (compute_antic_aux): Make non-recursive.
	(compute_antic): Iterate from here using a DFS.  Use an sbitmap
	instead of BB_VISITED.

From-SVN: r93654