tree-loop-distribution.c (dot_rdg_1): Make graph prettier.

tree-loop-distribution.c (dot_rdg_1): Make graph prettier.

2013-09-12  Richard Biener  <rguenther@suse.de>

	* tree-loop-distribution.c (dot_rdg_1): Make graph prettier.
	(dot_rdg): Use popen instead of system in optional code.
	(remaining_stmts, upstream_mem_writes): Remove global bitmaps.
	(already_processed_vertex_p): Adjust.
	(has_anti_or_output_dependence, predecessor_has_mem_write,
	mark_nodes_having_upstream_mem_writes, has_upstream_mem_writes,
	rdg_flag_uses): Remove.
	(rdg_flag_vertex): Simplify.
	(rdg_flag_vertex_and_dependent): Rely on a correct RDG and
	remove recursion.
	(build_rdg_partition_for_component): Process the first vertex
	of a component only.
	(ldist_gen): Do not compute remaining_stmts or upstream_mem_writes.

	* gcc.dg/tree-ssa/ldist-4.c: Remove undefined behavior.  Adjust
	expected outcome and comment why that happens.

From-SVN: r202516