4 * Copyright: (c) Universitaet Karlsruhe
5 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
8 * ILP formalization using G=(V, E, Q):
9 * - 2 class of variables: coloring vars x_ic and equal color vars y_ij
11 * - Clique-star constraints
14 * \min \sum_{ (i,j) \in Q } w_ij y_ij
16 * \sum_c x_nc = 1 n \in N, c \in C
18 * x_nc = 0 n \in N, c \not\in C(n)
20 * \sum x_nc <= 1 x_nc \in Clique \in AllCliques, c \in C
22 * \sum_{e \in p} y_e >= 1 p \in P path constraints
24 * \sum_{e \in cs} y_e >= |cs| - 1 cs \in CP clique-star constraints
26 * x_nc, y_ij \in N, w_ij \in R^+
31 #endif /* HAVE_CONFIG_H */
40 #include "becopyilp_t.h"
42 #include "besched_t.h"
46 typedef struct _local_env_t {
48 int first_x_var, last_x_var;
50 DEBUG_ONLY(firm_dbg_module_t *dbg;)
53 static void build_coloring_cstr(ilp_env_t *ienv) {
54 be_ifg_t *ifg = ienv->co->cenv->ifg;
55 void *iter = be_ifg_nodes_iter_alloca(ifg);
60 colors = bitset_alloca(arch_register_class_n_regs(ienv->co->cls));
62 be_ifg_foreach_node(ifg, iter, irn)
63 if (!sr_is_removed(ienv->sr, irn)) {
65 arch_register_req_t req;
66 int curr_node_color = get_irn_col(ienv->co, irn);
67 int node_nr = (int)get_irn_node_nr(irn);
68 local_env_t *lenv = ienv->env;
70 pmap_insert(lenv->nr_2_irn, INT_TO_PTR(node_nr), irn);
72 arch_get_register_req(ienv->co->aenv, &req, irn, -1);
74 /* get assignable colors */
75 if (arch_register_req_is(&req, limited))
76 req.limited(req.limited_env, colors);
78 arch_register_class_put(req.cls, colors);
79 // bitset_andnot(colors, ienv->co->cenv->ignore_colors);
82 /* add the coloring constraint */
83 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 1.0);
85 bitset_foreach(colors, col) {
86 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
87 lpp_set_start_value(ienv->lp, var_idx, (col == curr_node_color) ? 1.0 : 0.0);
88 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
90 lenv->last_x_var = var_idx;
91 if (lenv->first_x_var == -1)
92 lenv->first_x_var = var_idx;
95 /* add register constraint constraints */
96 bitset_foreach_clear(colors, col) {
97 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 0.0);
98 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
99 lpp_set_start_value(ienv->lp, var_idx, 0.0);
100 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
102 lenv->last_x_var = var_idx;
107 static void build_interference_cstr(ilp_env_t *ienv) {
108 lpp_t *lpp = ienv->lp;
109 be_ifg_t *ifg = ienv->co->cenv->ifg;
110 int n_colors = arch_register_class_n_regs(ienv->co->cls);
113 void *iter = be_ifg_cliques_iter_alloca(ifg);
114 ir_node **clique = alloca(sizeof(*clique) * n_colors);
119 /* for each maximal clique */
120 be_ifg_foreach_clique(ifg, iter, clique, &size) {
123 for (i=0; i<size; ++i)
124 if (!sr_is_removed(ienv->sr, clique[i]))
131 for (col=0; col<n_colors; ++col) {
132 int cst_idx = lpp_add_cst(lpp, NULL, lpp_less, 1.0);
134 /* for each member of this clique */
135 for (i=0; i<size; ++i) {
136 ir_node *irn = clique[i];
138 if (!sr_is_removed(ienv->sr, irn)) {
139 int var_idx = lpp_get_var_idx(lpp, name_cdd(buf, 'x', (int)get_irn_node_nr(irn), col));
140 lpp_set_factor_fast(lpp, cst_idx, var_idx, 1);
149 * TODO: Remove the dependency of the opt-units data structure
150 * by walking over all affinity edges. Graph structure
151 * does not provide this walker, yet.
153 static void build_affinity_cstr(ilp_env_t *ienv) {
155 int n_colors = arch_register_class_n_regs(ienv->co->cls);
157 /* for all optimization units */
158 list_for_each_entry(unit_t, curr, &ienv->co->units, units) {
160 int root_nr, arg_nr, i, col, y_idx, root_idx, arg_idx;
162 int root_col, arg_col;
164 root = curr->nodes[0];
165 root_nr = (int) get_irn_node_nr(root);
166 root_col = get_irn_col(ienv->co, root);
168 for (i = 1; i < curr->node_count; ++i) {
169 arg = curr->nodes[i];
170 arg_nr = (int) get_irn_node_nr(arg);
171 arg_col = get_irn_col(ienv->co, arg);
173 /* add a new affinity variable */
174 y_idx = lpp_add_var(ienv->lp, name_cdd_sorted(buf, 'y', root_nr, arg_nr), lpp_binary, curr->costs[i]);
175 lpp_set_start_value(ienv->lp, y_idx, (root_col==arg_col) ? 0.0 : 1.0);
177 /* add constraints relating the affinity var to the color vars */
178 for (col=0; col<n_colors; ++col) {
179 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_less, 0.0);
180 root_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', root_nr, col));
181 arg_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', arg_nr, col));
183 lpp_set_factor_fast(ienv->lp, cst_idx, root_idx, 1.0);
184 lpp_set_factor_fast(ienv->lp, cst_idx, arg_idx, -1.0);
185 lpp_set_factor_fast(ienv->lp, cst_idx, y_idx, -1.0);
192 * Helping stuff for build_clique_star_cstr
194 typedef struct _edge_t {
198 static int compare_edge_t(const void *k1, const void *k2, size_t size) {
199 const edge_t *e1 = k1;
200 const edge_t *e2 = k2;
202 return ! (e1->n1 == e2->n1 && e1->n2 == e2->n2);
205 #define HASH_EDGE(e) (HASH_PTR((e)->n1) ^ HASH_PTR((e)->n2))
207 static INLINE edge_t *add_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
210 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
218 return set_insert(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
221 static INLINE edge_t *find_edge(set *edges, ir_node *n1, ir_node *n2) {
224 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
231 return set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
234 static INLINE void remove_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
237 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
244 e = set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
252 #define pset_foreach(pset, irn) for(irn=pset_first(pset); irn; irn=pset_next(pset))
255 * Search for an interference clique and an external node
256 * with affinity edges to all nodes of the clique.
257 * At most 1 node of the clique can be colored equally with the external node.
259 static void build_clique_star_cstr(ilp_env_t *ienv) {
260 affinity_node_t *aff;
262 /* for each node with affinity edges */
263 co_gs_foreach_aff_node(ienv->co, aff) {
266 ir_node *center = aff->irn;
269 int i, o, n_nodes, n_edges;
272 edges = new_set(compare_edge_t, 8);
274 /* get all affinity neighbours */
276 co_gs_foreach_neighb(aff, nbr) {
277 obstack_ptr_grow(&ob, nbr->irn);
280 nodes = obstack_finish(&ob);
282 /* get all interference edges between these */
284 for (i=0; i<n_nodes; ++i)
286 if (be_ifg_connected(ienv->co->cenv->ifg, nodes[i], nodes[o]))
287 add_edge(edges, nodes[i], nodes[o], &n_edges);
289 /* cover all these interference edges with maximal cliques */
292 pset *clique = pset_new_ptr(8);
295 /* get 2 starting nodes to form a clique */
296 for (e=set_first(edges); !e->n1; e=set_next(edges))
299 pset_insert_ptr(clique, e->n1);
300 pset_insert_ptr(clique, e->n2);
301 remove_edge(edges, e->n1, e->n2, &n_edges);
303 /* while the clique is growing */
307 /* search for a candidate to extend the clique */
308 for (i=0; i<n_nodes; ++i) {
309 ir_node *member, *cand = nodes[i];
312 /* if its already in the clique try the next */
313 if (pset_find_ptr(clique, cand))
316 /* are there all necessary interferences? */
318 pset_foreach(clique, member) {
319 if (!find_edge(edges, cand, member)) {
326 /* now we know if we have a clique extender */
328 /* first remove all covered edges */
329 pset_foreach(clique, member)
330 remove_edge(edges, cand, member, &n_edges);
332 /* insert into clique */
333 pset_insert_ptr(clique, cand);
340 /* now the clique is maximal. Finally add the constraint */
343 int var_idx, cst_idx, center_nr, member_nr;
346 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, pset_count(clique)-1);
347 center_nr = get_irn_node_nr(center);
349 pset_foreach(clique, member) {
350 member_nr = get_irn_node_nr(member);
351 var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', center_nr, member_nr));
352 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
360 obstack_free(&ob, NULL);
365 static void extend_path(ilp_env_t *ienv, pdeq *path, ir_node *irn) {
366 be_ifg_t *ifg = ienv->co->cenv->ifg;
369 affinity_node_t *aff;
372 /* do not walk backwards or in circles */
373 if (pdeq_contains(path, irn))
376 /* insert the new irn */
377 pdeq_putr(path, irn);
381 /* check for forbidden interferences */
382 len = pdeq_len(path);
383 curr_path = alloca(len * sizeof(*curr_path));
384 pdeq_copyl(path, (const void **)curr_path);
386 for (i=1; i<len; ++i)
387 if (be_ifg_connected(ifg, irn, curr_path[i]))
392 /* check for terminating interference */
393 if (be_ifg_connected(ifg, irn, curr_path[0])) {
395 /* One node is not a path. */
396 /* And a path of length 2 is covered by a clique star constraint. */
398 /* finally build the constraint */
399 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, 1.0);
400 for (i=1; i<len; ++i) {
402 int nr_1 = get_irn_node_nr(curr_path[i-1]);
403 int nr_2 = get_irn_node_nr(curr_path[i]);
404 int var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', nr_1, nr_2));
405 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
409 /* this path cannot be extended anymore */
415 /* recursively extend the path */
416 aff = get_affinity_info(ienv->co, irn);
417 co_gs_foreach_neighb(aff, nbr)
418 extend_path(ienv, path, nbr->irn);
428 * Search a path of affinity edges, whose ends are connected
429 * by an interference edge and there are no other interference
431 * Then at least one of these affinity edges must break.
433 static void build_path_cstr(ilp_env_t *ienv) {
434 affinity_node_t *aff_info;
436 /* for each node with affinity edges */
437 co_gs_foreach_aff_node(ienv->co, aff_info) {
438 pdeq *path = new_pdeq();
440 extend_path(ienv, path, aff_info->irn);
446 static void ilp2_build(ilp_env_t *ienv) {
447 local_env_t *lenv = ienv->env;
450 ienv->lp = new_lpp(ienv->co->name, lpp_minimize);
451 build_coloring_cstr(ienv);
452 build_interference_cstr(ienv);
453 build_affinity_cstr(ienv);
454 build_clique_star_cstr(ienv);
455 build_path_cstr(ienv);
457 lower_bound = co_get_lower_bound(ienv->co) - co_get_inevit_copy_costs(ienv->co);
458 lpp_set_bound(ienv->lp, lower_bound);
459 lpp_set_time_limit(ienv->lp, lenv->time_limit);
462 static void ilp2_apply(ilp_env_t *ienv) {
463 local_env_t *lenv = ienv->env;
465 lpp_sol_state_t state;
468 /* first check if there was sth. to optimize */
469 if (lenv->first_x_var >= 0) {
471 count = lenv->last_x_var - lenv->first_x_var + 1;
472 sol = xmalloc(count * sizeof(sol[0]));
473 state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
474 if (state != lpp_optimal) {
475 printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
476 assert(state >= lpp_feasible && "The solution should at least be feasible!");
479 for (i=0; i<count; ++i) {
483 if (sol[i] > 1-EPSILON) { /* split variable name into components */
484 lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
486 if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
487 ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
488 assert(irn && "This node number must be present in the map");
490 set_irn_col(ienv->co, irn, color);
492 assert(0 && "This should be a x-var");
498 /* TODO adapt to multiple possible ILPs */
499 copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp))); //now we have ms
500 copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
501 copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
502 copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
506 int co_solve_ilp2(copy_opt_t *co, double time_limit) {
507 lpp_sol_state_t sol_state;
511 ASSERT_OU_AVAIL(co); //See build_clique_st
514 my.time_limit = time_limit;
517 my.nr_2_irn = pmap_create();
518 FIRM_DBG_REGISTER(my.dbg, "firm.be.coilp2");
520 ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);
522 sol_state = ilp_go(ienv);
524 pmap_destroy(my.nr_2_irn);
527 return sol_state == lpp_optimal;
532 static void only_that_you_can_compile_without_WITH_ILP_defined(void) {
535 #endif /* WITH_ILP */