col = bitset_next_set(bs, 0);
reg = arch_register_for_index(env->cls, col);
pset_insert_ptr(pre_colored, irn);
arch_set_irn_register(env->main_env->arch_env, irn, reg);
col = bitset_next_set(bs, 0);
reg = arch_register_for_index(env->cls, col);
pset_insert_ptr(pre_colored, irn);
arch_set_irn_register(env->main_env->arch_env, irn, reg);