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 */
36 #include "raw_bitset.h"
41 #include "becopyilp_t.h"
43 #include "besched_t.h"
44 #include "benodesets.h"
48 typedef struct _local_env_t {
50 int first_x_var, last_x_var;
52 DEBUG_ONLY(firm_dbg_module_t *dbg;)
55 static void build_coloring_cstr(ilp_env_t *ienv) {
56 be_ifg_t *ifg = ienv->co->cenv->ifg;
57 void *iter = be_ifg_nodes_iter_alloca(ifg);
62 colors = bitset_alloca(arch_register_class_n_regs(ienv->co->cls));
64 be_ifg_foreach_node(ifg, iter, irn)
65 if (!sr_is_removed(ienv->sr, irn)) {
67 const arch_register_req_t *req;
68 int curr_node_color = get_irn_col(ienv->co, irn);
69 int node_nr = (int)get_irn_node_nr(irn);
70 local_env_t *lenv = ienv->env;
72 pmap_insert(lenv->nr_2_irn, INT_TO_PTR(node_nr), irn);
74 req = arch_get_register_req(ienv->co->aenv, irn, -1);
76 /* get assignable colors */
77 if (arch_register_req_is(req, limited)) {
78 rbitset_copy_to_bitset(req->limited, colors);
80 arch_register_class_put(req->cls, colors);
81 // bitset_andnot(colors, ienv->co->cenv->ignore_colors);
84 /* add the coloring constraint */
85 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 1.0);
87 bitset_foreach(colors, col) {
88 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
89 lpp_set_start_value(ienv->lp, var_idx, (col == curr_node_color) ? 1.0 : 0.0);
90 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
92 lenv->last_x_var = var_idx;
93 if (lenv->first_x_var == -1)
94 lenv->first_x_var = var_idx;
97 /* add register constraint constraints */
98 bitset_foreach_clear(colors, col) {
99 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 0.0);
100 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
101 lpp_set_start_value(ienv->lp, var_idx, 0.0);
102 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
104 lenv->last_x_var = var_idx;
109 static void build_interference_cstr(ilp_env_t *ienv) {
110 lpp_t *lpp = ienv->lp;
111 be_ifg_t *ifg = ienv->co->cenv->ifg;
112 int n_colors = arch_register_class_n_regs(ienv->co->cls);
115 void *iter = be_ifg_cliques_iter_alloca(ifg);
116 ir_node **clique = alloca(sizeof(*clique) * n_colors);
121 /* for each maximal clique */
122 be_ifg_foreach_clique(ifg, iter, clique, &size) {
125 for (i=0; i<size; ++i)
126 if (!sr_is_removed(ienv->sr, clique[i]))
133 for (col=0; col<n_colors; ++col) {
134 int cst_idx = lpp_add_cst(lpp, NULL, lpp_less, 1.0);
136 /* for each member of this clique */
137 for (i=0; i<size; ++i) {
138 ir_node *irn = clique[i];
140 if (!sr_is_removed(ienv->sr, irn)) {
141 int var_idx = lpp_get_var_idx(lpp, name_cdd(buf, 'x', (int)get_irn_node_nr(irn), col));
142 lpp_set_factor_fast(lpp, cst_idx, var_idx, 1);
151 * TODO: Remove the dependency of the opt-units data structure
152 * by walking over all affinity edges. Graph structure
153 * does not provide this walker, yet.
155 static void build_affinity_cstr(ilp_env_t *ienv) {
157 int n_colors = arch_register_class_n_regs(ienv->co->cls);
159 /* for all optimization units */
160 list_for_each_entry(unit_t, curr, &ienv->co->units, units) {
162 int root_nr, arg_nr, i, col, y_idx, root_idx, arg_idx;
164 int root_col, arg_col;
166 root = curr->nodes[0];
167 root_nr = (int) get_irn_node_nr(root);
168 root_col = get_irn_col(ienv->co, root);
170 for (i = 1; i < curr->node_count; ++i) {
171 arg = curr->nodes[i];
172 arg_nr = (int) get_irn_node_nr(arg);
173 arg_col = get_irn_col(ienv->co, arg);
175 /* add a new affinity variable */
176 y_idx = lpp_add_var(ienv->lp, name_cdd_sorted(buf, 'y', root_nr, arg_nr), lpp_binary, curr->costs[i]);
177 lpp_set_start_value(ienv->lp, y_idx, (root_col==arg_col) ? 0.0 : 1.0);
179 /* add constraints relating the affinity var to the color vars */
180 for (col=0; col<n_colors; ++col) {
181 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_less, 0.0);
182 root_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', root_nr, col));
183 arg_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', arg_nr, col));
185 lpp_set_factor_fast(ienv->lp, cst_idx, root_idx, 1.0);
186 lpp_set_factor_fast(ienv->lp, cst_idx, arg_idx, -1.0);
187 lpp_set_factor_fast(ienv->lp, cst_idx, y_idx, -1.0);
194 * Helping stuff for build_clique_star_cstr
196 typedef struct _edge_t {
200 static int compare_edge_t(const void *k1, const void *k2, size_t size) {
201 const edge_t *e1 = k1;
202 const edge_t *e2 = k2;
204 return ! (e1->n1 == e2->n1 && e1->n2 == e2->n2);
207 #define HASH_EDGE(e) (nodeset_hash((e)->n1) ^ nodeset_hash((e)->n2))
209 static INLINE edge_t *add_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
212 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
220 return set_insert(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
223 static INLINE edge_t *find_edge(set *edges, ir_node *n1, ir_node *n2) {
226 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
233 return set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
236 static INLINE void remove_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
239 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
246 e = set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
254 #define pset_foreach(pset, irn) for(irn=pset_first(pset); irn; irn=pset_next(pset))
257 * Search for an interference clique and an external node
258 * with affinity edges to all nodes of the clique.
259 * At most 1 node of the clique can be colored equally with the external node.
261 static void build_clique_star_cstr(ilp_env_t *ienv) {
262 affinity_node_t *aff;
264 /* for each node with affinity edges */
265 co_gs_foreach_aff_node(ienv->co, aff) {
268 ir_node *center = aff->irn;
271 int i, o, n_nodes, n_edges;
274 edges = new_set(compare_edge_t, 8);
276 /* get all affinity neighbours */
278 co_gs_foreach_neighb(aff, nbr) {
279 obstack_ptr_grow(&ob, nbr->irn);
282 nodes = obstack_finish(&ob);
284 /* get all interference edges between these */
286 for (i=0; i<n_nodes; ++i)
288 if (be_ifg_connected(ienv->co->cenv->ifg, nodes[i], nodes[o]))
289 add_edge(edges, nodes[i], nodes[o], &n_edges);
291 /* cover all these interference edges with maximal cliques */
294 pset *clique = pset_new_ptr(8);
297 /* get 2 starting nodes to form a clique */
298 for (e=set_first(edges); !e->n1; e=set_next(edges))
301 /* we could be stepped out of the loop before the set iterated to the end */
304 pset_insert_ptr(clique, e->n1);
305 pset_insert_ptr(clique, e->n2);
306 remove_edge(edges, e->n1, e->n2, &n_edges);
308 /* while the clique is growing */
312 /* search for a candidate to extend the clique */
313 for (i=0; i<n_nodes; ++i) {
314 ir_node *member, *cand = nodes[i];
317 /* if its already in the clique try the next */
318 if (pset_find_ptr(clique, cand))
321 /* are there all necessary interferences? */
323 pset_foreach(clique, member) {
324 if (!find_edge(edges, cand, member)) {
331 /* now we know if we have a clique extender */
333 /* first remove all covered edges */
334 pset_foreach(clique, member)
335 remove_edge(edges, cand, member, &n_edges);
337 /* insert into clique */
338 pset_insert_ptr(clique, cand);
345 /* now the clique is maximal. Finally add the constraint */
348 int var_idx, cst_idx, center_nr, member_nr;
351 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, pset_count(clique)-1);
352 center_nr = get_irn_node_nr(center);
354 pset_foreach(clique, member) {
355 member_nr = get_irn_node_nr(member);
356 var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', center_nr, member_nr));
357 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
365 obstack_free(&ob, NULL);
370 static void extend_path(ilp_env_t *ienv, pdeq *path, ir_node *irn) {
371 be_ifg_t *ifg = ienv->co->cenv->ifg;
374 affinity_node_t *aff;
377 /* do not walk backwards or in circles */
378 if (pdeq_contains(path, irn))
381 /* insert the new irn */
382 pdeq_putr(path, irn);
386 /* check for forbidden interferences */
387 len = pdeq_len(path);
388 curr_path = alloca(len * sizeof(*curr_path));
389 pdeq_copyl(path, (const void **)curr_path);
391 for (i=1; i<len; ++i)
392 if (be_ifg_connected(ifg, irn, curr_path[i]))
397 /* check for terminating interference */
398 if (be_ifg_connected(ifg, irn, curr_path[0])) {
400 /* One node is not a path. */
401 /* And a path of length 2 is covered by a clique star constraint. */
403 /* finally build the constraint */
404 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, 1.0);
405 for (i=1; i<len; ++i) {
407 int nr_1 = get_irn_node_nr(curr_path[i-1]);
408 int nr_2 = get_irn_node_nr(curr_path[i]);
409 int var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', nr_1, nr_2));
410 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
414 /* this path cannot be extended anymore */
420 /* recursively extend the path */
421 aff = get_affinity_info(ienv->co, irn);
422 co_gs_foreach_neighb(aff, nbr)
423 extend_path(ienv, path, nbr->irn);
433 * Search a path of affinity edges, whose ends are connected
434 * by an interference edge and there are no other interference
436 * Then at least one of these affinity edges must break.
438 static void build_path_cstr(ilp_env_t *ienv) {
439 affinity_node_t *aff_info;
441 /* for each node with affinity edges */
442 co_gs_foreach_aff_node(ienv->co, aff_info) {
443 pdeq *path = new_pdeq();
445 extend_path(ienv, path, aff_info->irn);
451 static void ilp2_build(ilp_env_t *ienv) {
452 local_env_t *lenv = ienv->env;
455 ienv->lp = new_lpp(ienv->co->name, lpp_minimize);
456 build_coloring_cstr(ienv);
457 build_interference_cstr(ienv);
458 build_affinity_cstr(ienv);
459 build_clique_star_cstr(ienv);
460 build_path_cstr(ienv);
462 lower_bound = co_get_lower_bound(ienv->co) - co_get_inevit_copy_costs(ienv->co);
463 lpp_set_bound(ienv->lp, lower_bound);
464 lpp_set_time_limit(ienv->lp, lenv->time_limit);
467 static void ilp2_apply(ilp_env_t *ienv) {
468 local_env_t *lenv = ienv->env;
470 lpp_sol_state_t state;
473 /* first check if there was sth. to optimize */
474 if (lenv->first_x_var >= 0) {
476 count = lenv->last_x_var - lenv->first_x_var + 1;
477 sol = xmalloc(count * sizeof(sol[0]));
478 state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
479 if (state != lpp_optimal) {
480 printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
481 assert(state >= lpp_feasible && "The solution should at least be feasible!");
484 for (i=0; i<count; ++i) {
488 if (sol[i] > 1-EPSILON) { /* split variable name into components */
489 lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
491 if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
492 ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
493 assert(irn && "This node number must be present in the map");
495 set_irn_col(ienv->co, irn, color);
497 assert(0 && "This should be a x-var");
503 /* TODO adapt to multiple possible ILPs */
504 copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp))); //now we have ms
505 copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
506 copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
507 copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
511 int co_solve_ilp2(copy_opt_t *co) {
512 lpp_sol_state_t sol_state;
516 ASSERT_OU_AVAIL(co); //See build_clique_st
522 my.nr_2_irn = pmap_create();
523 FIRM_DBG_REGISTER(my.dbg, "firm.be.coilp2");
525 ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);
527 sol_state = ilp_go(ienv);
529 pmap_destroy(my.nr_2_irn);
532 return sol_state == lpp_optimal;
537 static INLINE void only_that_you_can_compile_without_WITH_ILP_defined(void) {
540 #endif /* WITH_ILP */