+
+static inline void remove_edge(set *edges, ir_node *n1, ir_node *n2, int *counter)
+{
+ edge_t new_edge, *e;
+
+ if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
+ new_edge.n1 = n1;
+ new_edge.n2 = n2;
+ } else {
+ new_edge.n1 = n2;
+ new_edge.n2 = n1;
+ }
+ e = set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
+ if (e) {
+ e->n1 = NULL;
+ e->n2 = NULL;
+ (*counter)--;
+ }
+}
+
+#define pset_foreach(pset, irn) for (irn=pset_first(pset); irn; irn=pset_next(pset))
+
+/**
+ * Search for an interference clique and an external node
+ * with affinity edges to all nodes of the clique.
+ * At most 1 node of the clique can be colored equally with the external node.
+ */
+static void build_clique_star_cstr(ilp_env_t *ienv)
+{
+ affinity_node_t *aff;
+
+ /* for each node with affinity edges */
+ co_gs_foreach_aff_node(ienv->co, aff) {
+ struct obstack ob;
+ neighb_t *nbr;
+ const ir_node *center = aff->irn;
+ ir_node **nodes;
+ set *edges;
+ int i, o, n_nodes, n_edges;
+
+ if (arch_irn_is_ignore(aff->irn))
+ continue;
+
+ obstack_init(&ob);
+ edges = new_set(compare_edge_t, 8);
+
+ /* get all affinity neighbours */
+ n_nodes = 0;
+ co_gs_foreach_neighb(aff, nbr) {
+ if (!arch_irn_is_ignore(nbr->irn)) {
+ obstack_ptr_grow(&ob, nbr->irn);
+ ++n_nodes;
+ }
+ }
+ nodes = obstack_finish(&ob);
+
+ /* get all interference edges between these */
+ n_edges = 0;
+ for (i=0; i<n_nodes; ++i)
+ for (o=0; o<i; ++o)
+ if (be_ifg_connected(ienv->co->cenv->ifg, nodes[i], nodes[o]))
+ add_edge(edges, nodes[i], nodes[o], &n_edges);
+
+ /* cover all these interference edges with maximal cliques */
+ while (n_edges) {
+ edge_t *e;
+ pset *clique = pset_new_ptr(8);
+ int growed;
+
+ /* get 2 starting nodes to form a clique */
+ for (e=set_first(edges); !e->n1; e=set_next(edges))
+ /*nothing*/ ;
+
+ /* we could be stepped out of the loop before the set iterated to the end */
+ set_break(edges);
+
+ pset_insert_ptr(clique, e->n1);
+ pset_insert_ptr(clique, e->n2);
+ remove_edge(edges, e->n1, e->n2, &n_edges);
+
+ /* while the clique is growing */
+ do {
+ growed = 0;
+
+ /* search for a candidate to extend the clique */
+ for (i=0; i<n_nodes; ++i) {
+ ir_node *member, *cand = nodes[i];
+ int is_cand;
+
+ /* if its already in the clique try the next */
+ if (pset_find_ptr(clique, cand))
+ continue;
+
+ /* are there all necessary interferences? */
+ is_cand = 1;
+ pset_foreach(clique, member) {
+ if (!find_edge(edges, cand, member)) {
+ is_cand = 0;
+ pset_break(clique);
+ break;
+ }
+ }
+
+ /* now we know if we have a clique extender */
+ if (is_cand) {
+ /* first remove all covered edges */
+ pset_foreach(clique, member)
+ remove_edge(edges, cand, member, &n_edges);
+
+ /* insert into clique */
+ pset_insert_ptr(clique, cand);
+ growed = 1;
+ break;
+ }
+ }
+ } while (growed);
+
+ /* now the clique is maximal. Finally add the constraint */
+ {
+ ir_node *member;
+ int var_idx, cst_idx, center_nr, member_nr;
+ char buf[16];
+
+ cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, pset_count(clique)-1);
+ center_nr = get_irn_idx(center);
+
+ pset_foreach(clique, member) {
+ member_nr = get_irn_idx(member);
+ var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', center_nr, member_nr));
+ lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
+ }
+ }
+
+ del_pset(clique);
+ }
+
+ del_set(edges);
+ obstack_free(&ob, NULL);
+ }
+}
+
+
+static void extend_path(ilp_env_t *ienv, pdeq *path, const ir_node *irn)
+{
+ be_ifg_t *ifg = ienv->co->cenv->ifg;
+ int i, len;
+ ir_node **curr_path;
+ affinity_node_t *aff;
+ neighb_t *nbr;
+
+ /* do not walk backwards or in circles */
+ if (pdeq_contains(path, irn))
+ return;
+
+ if (arch_irn_is_ignore(irn))
+ return;
+
+ /* insert the new irn */
+ pdeq_putr(path, irn);
+
+
+
+ /* check for forbidden interferences */
+ len = pdeq_len(path);
+ curr_path = ALLOCAN(ir_node*, len);
+ pdeq_copyl(path, (const void **)curr_path);
+
+ for (i=1; i<len; ++i)
+ if (be_ifg_connected(ifg, irn, curr_path[i]))
+ goto end;
+
+
+
+ /* check for terminating interference */
+ if (be_ifg_connected(ifg, irn, curr_path[0])) {
+
+ /* One node is not a path. */
+ /* And a path of length 2 is covered by a clique star constraint. */
+ if (len > 2) {
+ /* finally build the constraint */
+ int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, 1.0);
+ for (i=1; i<len; ++i) {
+ char buf[16];
+ int nr_1 = get_irn_idx(curr_path[i-1]);
+ int nr_2 = get_irn_idx(curr_path[i]);
+ int var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', nr_1, nr_2));
+ lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
+ }
+ }
+
+ /* this path cannot be extended anymore */
+ goto end;
+ }
+
+
+
+ /* recursively extend the path */
+ aff = get_affinity_info(ienv->co, irn);
+ co_gs_foreach_neighb(aff, nbr)
+ extend_path(ienv, path, nbr->irn);
+
+
+end:
+ /* remove the irn */
+ pdeq_getr(path);
+
+}
+
+/**
+ * Search a path of affinity edges, whose ends are connected
+ * by an interference edge and there are no other interference
+ * edges in between.
+ * Then at least one of these affinity edges must break.
+ */
+static void build_path_cstr(ilp_env_t *ienv)
+{
+ affinity_node_t *aff_info;
+
+ /* for each node with affinity edges */
+ co_gs_foreach_aff_node(ienv->co, aff_info) {
+ pdeq *path = new_pdeq();
+
+ extend_path(ienv, path, aff_info->irn);
+
+ del_pdeq(path);
+ }
+}
+
+static void ilp2_build(ilp_env_t *ienv)
+{
+ local_env_t *lenv = ienv->env;
+ int lower_bound;
+
+ ienv->lp = new_lpp(ienv->co->name, lpp_minimize);
+ build_coloring_cstr(ienv);
+ build_interference_cstr(ienv);
+ build_affinity_cstr(ienv);
+ build_clique_star_cstr(ienv);
+ build_path_cstr(ienv);
+
+ lower_bound = co_get_lower_bound(ienv->co) - co_get_inevit_copy_costs(ienv->co);
+ lpp_set_bound(ienv->lp, lower_bound);
+ lpp_set_time_limit(ienv->lp, lenv->time_limit);
+}
+
+static void ilp2_apply(ilp_env_t *ienv)
+{
+ local_env_t *lenv = ienv->env;
+ int i;
+
+ /* first check if there was sth. to optimize */
+ if (lenv->first_x_var >= 0) {
+ int count = lenv->last_x_var - lenv->first_x_var + 1;
+ double *sol = XMALLOCN(double, count);
+ lpp_sol_state_t state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
+
+ if (state != lpp_optimal) {
+ printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
+ assert(state >= lpp_feasible && "The solution should at least be feasible!");
+ }
+
+ for (i=0; i<count; ++i) {
+ int nodenr, color;
+ char var_name[16];
+
+ if (sol[i] > 1-EPSILON) { /* split variable name into components */
+ lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
+
+ if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
+ ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
+ assert(irn && "This node number must be present in the map");
+
+ set_irn_col(ienv->co, irn, color);
+ } else
+ assert(0 && "This should be a x-var");
+ }
+ }
+
+ xfree(sol);
+ }
+
+#ifdef COPYOPT_STAT
+ /* TODO adapt to multiple possible ILPs */
+ copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp))); //now we have ms
+ copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
+ copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
+ copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
+#endif
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyilp2);
+void be_init_copyilp2(void)
+{
+ static co_algo_info copyheur = {
+ co_solve_ilp2, 1
+ };
+
+ be_register_copyopt("ilp", ©heur);
+}
+
+int co_solve_ilp2(copy_opt_t *co)
+{
+ lpp_sol_state_t sol_state;
+ ilp_env_t *ienv;
+ local_env_t my;
+
+ ASSERT_OU_AVAIL(co); //See build_clique_st
+ ASSERT_GS_AVAIL(co);
+
+ my.time_limit = 0;
+ my.first_x_var = -1;
+ my.last_x_var = -1;
+ my.nr_2_irn = pmap_create();
+ FIRM_DBG_REGISTER(my.dbg, "firm.be.coilp2");
+
+ my.normal_colors = bitset_alloca(arch_register_class_n_regs(co->cls));
+ bitset_clear_all(my.normal_colors);
+ be_put_allocatable_regs(co->irg, co->cls, my.normal_colors);
+ my.n_colors = bitset_popcount(my.normal_colors);
+
+ ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);
+
+ sol_state = ilp_go(ienv);
+
+ pmap_destroy(my.nr_2_irn);
+ free_ilp_env(ienv);
+
+ return sol_state == lpp_optimal;
+}
+
+#else /* WITH_ILP */
+
+static inline void only_that_you_can_compile_without_WITH_ILP_defined(void)
+{
+}
+
+#endif /* WITH_ILP */