env.spilled = bitset_irg_obstack_alloc(&env.ob, irg);
env.extra_spilled = ir_nodeset_new(64);
env.n_blocks = 0;
irg_block_walk_graph(irg, NULL, collect_blocks, &env);
obstack_ptr_grow(&env.ob, NULL);
env.spilled = bitset_irg_obstack_alloc(&env.ob, irg);
env.extra_spilled = ir_nodeset_new(64);
env.n_blocks = 0;
irg_block_walk_graph(irg, NULL, collect_blocks, &env);
obstack_ptr_grow(&env.ob, NULL);