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"
43 #include "benodesets.h"
47 typedef struct _local_env_t {
49 int first_x_var, last_x_var;
51 DEBUG_ONLY(firm_dbg_module_t *dbg;)
54 static void build_coloring_cstr(ilp_env_t *ienv) {
55 be_ifg_t *ifg = ienv->co->cenv->ifg;
56 void *iter = be_ifg_nodes_iter_alloca(ifg);
61 colors = bitset_alloca(arch_register_class_n_regs(ienv->co->cls));
63 be_ifg_foreach_node(ifg, iter, irn)
64 if (!sr_is_removed(ienv->sr, irn)) {
66 arch_register_req_t req;
67 int curr_node_color = get_irn_col(ienv->co, irn);
68 int node_nr = (int)get_irn_node_nr(irn);
69 local_env_t *lenv = ienv->env;
71 pmap_insert(lenv->nr_2_irn, INT_TO_PTR(node_nr), irn);
73 arch_get_register_req(ienv->co->aenv, &req, irn, -1);
75 /* get assignable colors */
76 if (arch_register_req_is(&req, limited))
77 req.limited(req.limited_env, colors);
79 arch_register_class_put(req.cls, colors);
80 // bitset_andnot(colors, ienv->co->cenv->ignore_colors);
83 /* add the coloring constraint */
84 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 1.0);
86 bitset_foreach(colors, col) {
87 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
88 lpp_set_start_value(ienv->lp, var_idx, (col == curr_node_color) ? 1.0 : 0.0);
89 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
91 lenv->last_x_var = var_idx;
92 if (lenv->first_x_var == -1)
93 lenv->first_x_var = var_idx;
96 /* add register constraint constraints */
97 bitset_foreach_clear(colors, col) {
98 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 0.0);
99 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
100 lpp_set_start_value(ienv->lp, var_idx, 0.0);
101 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
103 lenv->last_x_var = var_idx;
108 static void build_interference_cstr(ilp_env_t *ienv) {
109 lpp_t *lpp = ienv->lp;
110 be_ifg_t *ifg = ienv->co->cenv->ifg;
111 int n_colors = arch_register_class_n_regs(ienv->co->cls);
114 void *iter = be_ifg_cliques_iter_alloca(ifg);
115 ir_node **clique = alloca(sizeof(*clique) * n_colors);
120 /* for each maximal clique */
121 be_ifg_foreach_clique(ifg, iter, clique, &size) {
124 for (i=0; i<size; ++i)
125 if (!sr_is_removed(ienv->sr, clique[i]))
132 for (col=0; col<n_colors; ++col) {
133 int cst_idx = lpp_add_cst(lpp, NULL, lpp_less, 1.0);
135 /* for each member of this clique */
136 for (i=0; i<size; ++i) {
137 ir_node *irn = clique[i];
139 if (!sr_is_removed(ienv->sr, irn)) {
140 int var_idx = lpp_get_var_idx(lpp, name_cdd(buf, 'x', (int)get_irn_node_nr(irn), col));
141 lpp_set_factor_fast(lpp, cst_idx, var_idx, 1);
150 * TODO: Remove the dependency of the opt-units data structure
151 * by walking over all affinity edges. Graph structure
152 * does not provide this walker, yet.
154 static void build_affinity_cstr(ilp_env_t *ienv) {
156 int n_colors = arch_register_class_n_regs(ienv->co->cls);
158 /* for all optimization units */
159 list_for_each_entry(unit_t, curr, &ienv->co->units, units) {
161 int root_nr, arg_nr, i, col, y_idx, root_idx, arg_idx;
163 int root_col, arg_col;
165 root = curr->nodes[0];
166 root_nr = (int) get_irn_node_nr(root);
167 root_col = get_irn_col(ienv->co, root);
169 for (i = 1; i < curr->node_count; ++i) {
170 arg = curr->nodes[i];
171 arg_nr = (int) get_irn_node_nr(arg);
172 arg_col = get_irn_col(ienv->co, arg);
174 /* add a new affinity variable */
175 y_idx = lpp_add_var(ienv->lp, name_cdd_sorted(buf, 'y', root_nr, arg_nr), lpp_binary, curr->costs[i]);
176 lpp_set_start_value(ienv->lp, y_idx, (root_col==arg_col) ? 0.0 : 1.0);
178 /* add constraints relating the affinity var to the color vars */
179 for (col=0; col<n_colors; ++col) {
180 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_less, 0.0);
181 root_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', root_nr, col));
182 arg_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', arg_nr, col));
184 lpp_set_factor_fast(ienv->lp, cst_idx, root_idx, 1.0);
185 lpp_set_factor_fast(ienv->lp, cst_idx, arg_idx, -1.0);
186 lpp_set_factor_fast(ienv->lp, cst_idx, y_idx, -1.0);
193 * Helping stuff for build_clique_star_cstr
195 typedef struct _edge_t {
199 static int compare_edge_t(const void *k1, const void *k2, size_t size) {
200 const edge_t *e1 = k1;
201 const edge_t *e2 = k2;
203 return ! (e1->n1 == e2->n1 && e1->n2 == e2->n2);
206 #define HASH_EDGE(e) (nodeset_hash((e)->n1) ^ nodeset_hash((e)->n2))
208 static INLINE edge_t *add_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
211 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
219 return set_insert(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
222 static INLINE edge_t *find_edge(set *edges, ir_node *n1, ir_node *n2) {
225 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
232 return set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
235 static INLINE void remove_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
238 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
245 e = set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
253 #define pset_foreach(pset, irn) for(irn=pset_first(pset); irn; irn=pset_next(pset))
256 * Search for an interference clique and an external node
257 * with affinity edges to all nodes of the clique.
258 * At most 1 node of the clique can be colored equally with the external node.
260 static void build_clique_star_cstr(ilp_env_t *ienv) {
261 affinity_node_t *aff;
263 /* for each node with affinity edges */
264 co_gs_foreach_aff_node(ienv->co, aff) {
267 ir_node *center = aff->irn;
270 int i, o, n_nodes, n_edges;
273 edges = new_set(compare_edge_t, 8);
275 /* get all affinity neighbours */
277 co_gs_foreach_neighb(aff, nbr) {
278 obstack_ptr_grow(&ob, nbr->irn);
281 nodes = obstack_finish(&ob);
283 /* get all interference edges between these */
285 for (i=0; i<n_nodes; ++i)
287 if (be_ifg_connected(ienv->co->cenv->ifg, nodes[i], nodes[o]))
288 add_edge(edges, nodes[i], nodes[o], &n_edges);
290 /* cover all these interference edges with maximal cliques */
293 pset *clique = pset_new_ptr(8);
296 /* get 2 starting nodes to form a clique */
297 for (e=set_first(edges); !e->n1; e=set_next(edges))
300 /* we could be stepped out of the loop before the set iterated to the end */
303 pset_insert_ptr(clique, e->n1);
304 pset_insert_ptr(clique, e->n2);
305 remove_edge(edges, e->n1, e->n2, &n_edges);
307 /* while the clique is growing */
311 /* search for a candidate to extend the clique */
312 for (i=0; i<n_nodes; ++i) {
313 ir_node *member, *cand = nodes[i];
316 /* if its already in the clique try the next */
317 if (pset_find_ptr(clique, cand))
320 /* are there all necessary interferences? */
322 pset_foreach(clique, member) {
323 if (!find_edge(edges, cand, member)) {
330 /* now we know if we have a clique extender */
332 /* first remove all covered edges */
333 pset_foreach(clique, member)
334 remove_edge(edges, cand, member, &n_edges);
336 /* insert into clique */
337 pset_insert_ptr(clique, cand);
344 /* now the clique is maximal. Finally add the constraint */
347 int var_idx, cst_idx, center_nr, member_nr;
350 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, pset_count(clique)-1);
351 center_nr = get_irn_node_nr(center);
353 pset_foreach(clique, member) {
354 member_nr = get_irn_node_nr(member);
355 var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', center_nr, member_nr));
356 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
364 obstack_free(&ob, NULL);
369 static void extend_path(ilp_env_t *ienv, pdeq *path, ir_node *irn) {
370 be_ifg_t *ifg = ienv->co->cenv->ifg;
373 affinity_node_t *aff;
376 /* do not walk backwards or in circles */
377 if (pdeq_contains(path, irn))
380 /* insert the new irn */
381 pdeq_putr(path, irn);
385 /* check for forbidden interferences */
386 len = pdeq_len(path);
387 curr_path = alloca(len * sizeof(*curr_path));
388 pdeq_copyl(path, (const void **)curr_path);
390 for (i=1; i<len; ++i)
391 if (be_ifg_connected(ifg, irn, curr_path[i]))
396 /* check for terminating interference */
397 if (be_ifg_connected(ifg, irn, curr_path[0])) {
399 /* One node is not a path. */
400 /* And a path of length 2 is covered by a clique star constraint. */
402 /* finally build the constraint */
403 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, 1.0);
404 for (i=1; i<len; ++i) {
406 int nr_1 = get_irn_node_nr(curr_path[i-1]);
407 int nr_2 = get_irn_node_nr(curr_path[i]);
408 int var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', nr_1, nr_2));
409 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
413 /* this path cannot be extended anymore */
419 /* recursively extend the path */
420 aff = get_affinity_info(ienv->co, irn);
421 co_gs_foreach_neighb(aff, nbr)
422 extend_path(ienv, path, nbr->irn);
432 * Search a path of affinity edges, whose ends are connected
433 * by an interference edge and there are no other interference
435 * Then at least one of these affinity edges must break.
437 static void build_path_cstr(ilp_env_t *ienv) {
438 affinity_node_t *aff_info;
440 /* for each node with affinity edges */
441 co_gs_foreach_aff_node(ienv->co, aff_info) {
442 pdeq *path = new_pdeq();
444 extend_path(ienv, path, aff_info->irn);
450 static void ilp2_build(ilp_env_t *ienv) {
451 local_env_t *lenv = ienv->env;
454 ienv->lp = new_lpp(ienv->co->name, lpp_minimize);
455 build_coloring_cstr(ienv);
456 build_interference_cstr(ienv);
457 build_affinity_cstr(ienv);
458 build_clique_star_cstr(ienv);
459 build_path_cstr(ienv);
461 lower_bound = co_get_lower_bound(ienv->co) - co_get_inevit_copy_costs(ienv->co);
462 lpp_set_bound(ienv->lp, lower_bound);
463 lpp_set_time_limit(ienv->lp, lenv->time_limit);
466 static void ilp2_apply(ilp_env_t *ienv) {
467 local_env_t *lenv = ienv->env;
469 lpp_sol_state_t state;
472 /* first check if there was sth. to optimize */
473 if (lenv->first_x_var >= 0) {
475 count = lenv->last_x_var - lenv->first_x_var + 1;
476 sol = xmalloc(count * sizeof(sol[0]));
477 state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
478 if (state != lpp_optimal) {
479 printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
480 assert(state >= lpp_feasible && "The solution should at least be feasible!");
483 for (i=0; i<count; ++i) {
487 if (sol[i] > 1-EPSILON) { /* split variable name into components */
488 lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
490 if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
491 ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
492 assert(irn && "This node number must be present in the map");
494 set_irn_col(ienv->co, irn, color);
496 assert(0 && "This should be a x-var");
502 /* TODO adapt to multiple possible ILPs */
503 copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp))); //now we have ms
504 copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
505 copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
506 copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
510 int co_solve_ilp2(copy_opt_t *co) {
511 lpp_sol_state_t sol_state;
515 ASSERT_OU_AVAIL(co); //See build_clique_st
521 my.nr_2_irn = pmap_create();
522 FIRM_DBG_REGISTER(my.dbg, "firm.be.coilp2");
524 ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);
526 sol_state = ilp_go(ienv);
528 pmap_destroy(my.nr_2_irn);
531 return sol_state == lpp_optimal;
536 static INLINE void only_that_you_can_compile_without_WITH_ILP_defined(void) {
539 #endif /* WITH_ILP */