/* do the work */
irg_block_walk_graph(chordal_env->irg, compute_block_start_info, NULL, &bel);
irg_block_walk_graph(chordal_env->irg, belady, NULL, &bel);
/* do the work */
irg_block_walk_graph(chordal_env->irg, compute_block_start_info, NULL, &bel);
irg_block_walk_graph(chordal_env->irg, belady, NULL, &bel);