2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
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8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief ILP based copy minimization.
23 * @author Daniel Grund
27 * ILP formalization using G=(V, E, Q):
28 * - 2 class of variables: coloring vars x_ic and equal color vars y_ij
30 * - Clique-star constraints
33 * \min \sum_{ (i,j) \in Q } w_ij y_ij
35 * \sum_c x_nc = 1 n \in N, c \in C
37 * x_nc = 0 n \in N, c \not\in C(n)
39 * \sum x_nc <= 1 x_nc \in Clique \in AllCliques, c \in C
41 * \sum_{e \in p} y_e >= 1 p \in P path constraints
43 * \sum_{e \in cs} y_e >= |cs| - 1 cs \in CP clique-star constraints
45 * x_nc, y_ij \in N, w_ij \in R^+
52 #include "raw_bitset.h"
57 #include "becopyilp_t.h"
64 typedef struct _local_env_t {
66 int first_x_var, last_x_var;
68 bitset_t *normal_colors;
70 DEBUG_ONLY(firm_dbg_module_t *dbg;)
73 static void build_coloring_cstr(ilp_env_t *ienv) {
74 be_ifg_t *ifg = ienv->co->cenv->ifg;
75 void *iter = be_ifg_nodes_iter_alloca(ifg);
80 colors = bitset_alloca(arch_register_class_n_regs(ienv->co->cls));
82 be_ifg_foreach_node(ifg, iter, irn)
83 if (!sr_is_removed(ienv->sr, irn)) {
86 const arch_register_req_t *req;
87 int curr_node_color = get_irn_col(irn);
88 int node_nr = (int)get_irn_idx(irn);
89 local_env_t *lenv = ienv->env;
91 pmap_insert(lenv->nr_2_irn, INT_TO_PTR(node_nr), irn);
93 req = arch_get_register_req_out(irn);
95 bitset_clear_all(colors);
97 /* get assignable colors */
98 if (arch_register_req_is(req, limited)) {
99 rbitset_copy_to_bitset(req->limited, colors);
101 bitset_copy(colors, lenv->normal_colors);
104 /* add the coloring constraint */
105 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 1.0);
107 bitset_foreach(colors, col) {
108 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
109 lpp_set_start_value(ienv->lp, var_idx, (col == (unsigned) curr_node_color) ? 1.0 : 0.0);
110 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
112 lenv->last_x_var = var_idx;
113 if (lenv->first_x_var == -1)
114 lenv->first_x_var = var_idx;
117 /* add register constraint constraints */
118 bitset_foreach_clear(colors, col) {
119 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 0.0);
120 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
121 lpp_set_start_value(ienv->lp, var_idx, 0.0);
122 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
124 lenv->last_x_var = var_idx;
129 static void build_interference_cstr(ilp_env_t *ienv)
131 lpp_t *lpp = ienv->lp;
132 local_env_t *lenv = ienv->env;
133 be_ifg_t *ifg = ienv->co->cenv->ifg;
134 int n_colors = lenv->n_colors;
135 void *iter = be_ifg_cliques_iter_alloca(ifg);
136 ir_node **clique = ALLOCAN(ir_node*, n_colors);
143 /* for each maximal clique */
144 be_ifg_foreach_clique(ifg, iter, clique, &size) {
147 for (i=0; i<size; ++i)
148 if (!sr_is_removed(ienv->sr, clique[i]))
155 for (col=0; col<n_colors; ++col) {
156 int cst_idx = lpp_add_cst(lpp, NULL, lpp_less, 1.0);
158 /* for each member of this clique */
159 for (i=0; i<size; ++i) {
160 ir_node *irn = clique[i];
162 if (!sr_is_removed(ienv->sr, irn)) {
163 int var_idx = lpp_get_var_idx(lpp, name_cdd(buf, 'x', (int)get_irn_idx(irn), col));
164 lpp_set_factor_fast(lpp, cst_idx, var_idx, 1);
173 * TODO: Remove the dependency of the opt-units data structure
174 * by walking over all affinity edges. Graph structure
175 * does not provide this walker, yet.
177 static void build_affinity_cstr(ilp_env_t *ienv) {
178 local_env_t *lenv = ienv->env;
179 int n_colors = lenv->n_colors;
182 /* for all optimization units */
183 list_for_each_entry(unit_t, curr, &ienv->co->units, units) {
185 int root_nr, arg_nr, i, col, y_idx, root_idx, arg_idx;
187 int root_col, arg_col;
189 root = curr->nodes[0];
190 root_nr = (int) get_irn_idx(root);
191 root_col = get_irn_col(root);
193 for (i = 1; i < curr->node_count; ++i) {
194 arg = curr->nodes[i];
195 arg_nr = (int) get_irn_idx(arg);
196 arg_col = get_irn_col(arg);
198 /* add a new affinity variable */
199 y_idx = lpp_add_var(ienv->lp, name_cdd_sorted(buf, 'y', root_nr, arg_nr), lpp_binary, curr->costs[i]);
200 lpp_set_start_value(ienv->lp, y_idx, (root_col==arg_col) ? 0.0 : 1.0);
202 /* add constraints relating the affinity var to the color vars */
203 for (col=0; col<n_colors; ++col) {
204 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_less, 0.0);
205 root_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', root_nr, col));
206 arg_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', arg_nr, col));
208 lpp_set_factor_fast(ienv->lp, cst_idx, root_idx, 1.0);
209 lpp_set_factor_fast(ienv->lp, cst_idx, arg_idx, -1.0);
210 lpp_set_factor_fast(ienv->lp, cst_idx, y_idx, -1.0);
217 * Helping stuff for build_clique_star_cstr
219 typedef struct _edge_t {
223 static int compare_edge_t(const void *k1, const void *k2, size_t size) {
224 const edge_t *e1 = k1;
225 const edge_t *e2 = k2;
228 return ! (e1->n1 == e2->n1 && e1->n2 == e2->n2);
231 #define HASH_EDGE(e) (hash_irn((e)->n1) ^ hash_irn((e)->n2))
233 static inline edge_t *add_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
236 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
244 return set_insert(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
247 static inline edge_t *find_edge(set *edges, ir_node *n1, ir_node *n2) {
250 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
257 return set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
260 static inline void remove_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
263 if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
270 e = set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
278 #define pset_foreach(pset, irn) for(irn=pset_first(pset); irn; irn=pset_next(pset))
281 * Search for an interference clique and an external node
282 * with affinity edges to all nodes of the clique.
283 * At most 1 node of the clique can be colored equally with the external node.
285 static void build_clique_star_cstr(ilp_env_t *ienv) {
286 affinity_node_t *aff;
288 /* for each node with affinity edges */
289 co_gs_foreach_aff_node(ienv->co, aff) {
292 const ir_node *center = aff->irn;
295 int i, o, n_nodes, n_edges;
297 if (arch_irn_is_ignore(aff->irn))
301 edges = new_set(compare_edge_t, 8);
303 /* get all affinity neighbours */
305 co_gs_foreach_neighb(aff, nbr) {
306 if (!arch_irn_is_ignore(nbr->irn)) {
307 obstack_ptr_grow(&ob, nbr->irn);
311 nodes = obstack_finish(&ob);
313 /* get all interference edges between these */
315 for (i=0; i<n_nodes; ++i)
317 if (be_ifg_connected(ienv->co->cenv->ifg, nodes[i], nodes[o]))
318 add_edge(edges, nodes[i], nodes[o], &n_edges);
320 /* cover all these interference edges with maximal cliques */
323 pset *clique = pset_new_ptr(8);
326 /* get 2 starting nodes to form a clique */
327 for (e=set_first(edges); !e->n1; e=set_next(edges))
330 /* we could be stepped out of the loop before the set iterated to the end */
333 pset_insert_ptr(clique, e->n1);
334 pset_insert_ptr(clique, e->n2);
335 remove_edge(edges, e->n1, e->n2, &n_edges);
337 /* while the clique is growing */
341 /* search for a candidate to extend the clique */
342 for (i=0; i<n_nodes; ++i) {
343 ir_node *member, *cand = nodes[i];
346 /* if its already in the clique try the next */
347 if (pset_find_ptr(clique, cand))
350 /* are there all necessary interferences? */
352 pset_foreach(clique, member) {
353 if (!find_edge(edges, cand, member)) {
360 /* now we know if we have a clique extender */
362 /* first remove all covered edges */
363 pset_foreach(clique, member)
364 remove_edge(edges, cand, member, &n_edges);
366 /* insert into clique */
367 pset_insert_ptr(clique, cand);
374 /* now the clique is maximal. Finally add the constraint */
377 int var_idx, cst_idx, center_nr, member_nr;
380 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, pset_count(clique)-1);
381 center_nr = get_irn_idx(center);
383 pset_foreach(clique, member) {
384 member_nr = get_irn_idx(member);
385 var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', center_nr, member_nr));
386 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
394 obstack_free(&ob, NULL);
399 static void extend_path(ilp_env_t *ienv, pdeq *path, const ir_node *irn) {
400 be_ifg_t *ifg = ienv->co->cenv->ifg;
403 affinity_node_t *aff;
406 /* do not walk backwards or in circles */
407 if (pdeq_contains(path, irn))
410 if (arch_irn_is_ignore(irn))
413 /* insert the new irn */
414 pdeq_putr(path, irn);
418 /* check for forbidden interferences */
419 len = pdeq_len(path);
420 curr_path = ALLOCAN(ir_node*, len);
421 pdeq_copyl(path, (const void **)curr_path);
423 for (i=1; i<len; ++i)
424 if (be_ifg_connected(ifg, irn, curr_path[i]))
429 /* check for terminating interference */
430 if (be_ifg_connected(ifg, irn, curr_path[0])) {
432 /* One node is not a path. */
433 /* And a path of length 2 is covered by a clique star constraint. */
435 /* finally build the constraint */
436 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, 1.0);
437 for (i=1; i<len; ++i) {
439 int nr_1 = get_irn_idx(curr_path[i-1]);
440 int nr_2 = get_irn_idx(curr_path[i]);
441 int var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', nr_1, nr_2));
442 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
446 /* this path cannot be extended anymore */
452 /* recursively extend the path */
453 aff = get_affinity_info(ienv->co, irn);
454 co_gs_foreach_neighb(aff, nbr)
455 extend_path(ienv, path, nbr->irn);
465 * Search a path of affinity edges, whose ends are connected
466 * by an interference edge and there are no other interference
468 * Then at least one of these affinity edges must break.
470 static void build_path_cstr(ilp_env_t *ienv) {
471 affinity_node_t *aff_info;
473 /* for each node with affinity edges */
474 co_gs_foreach_aff_node(ienv->co, aff_info) {
475 pdeq *path = new_pdeq();
477 extend_path(ienv, path, aff_info->irn);
483 static void ilp2_build(ilp_env_t *ienv) {
484 local_env_t *lenv = ienv->env;
487 ienv->lp = new_lpp(ienv->co->name, lpp_minimize);
488 build_coloring_cstr(ienv);
489 build_interference_cstr(ienv);
490 build_affinity_cstr(ienv);
491 build_clique_star_cstr(ienv);
492 build_path_cstr(ienv);
494 lower_bound = co_get_lower_bound(ienv->co) - co_get_inevit_copy_costs(ienv->co);
495 lpp_set_bound(ienv->lp, lower_bound);
496 lpp_set_time_limit(ienv->lp, lenv->time_limit);
499 static void ilp2_apply(ilp_env_t *ienv) {
500 local_env_t *lenv = ienv->env;
503 /* first check if there was sth. to optimize */
504 if (lenv->first_x_var >= 0) {
505 int count = lenv->last_x_var - lenv->first_x_var + 1;
506 double *sol = XMALLOCN(double, count);
507 lpp_sol_state_t state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
509 if (state != lpp_optimal) {
510 printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
511 assert(state >= lpp_feasible && "The solution should at least be feasible!");
514 for (i=0; i<count; ++i) {
518 if (sol[i] > 1-EPSILON) { /* split variable name into components */
519 lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
521 if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
522 ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
523 assert(irn && "This node number must be present in the map");
525 set_irn_col(ienv->co, irn, color);
527 assert(0 && "This should be a x-var");
535 /* TODO adapt to multiple possible ILPs */
536 copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp))); //now we have ms
537 copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
538 copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
539 copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
543 void be_init_copyilp2(void)
545 static co_algo_info copyheur = {
549 be_register_copyopt("ilp", ©heur);
552 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyilp2);
554 int co_solve_ilp2(copy_opt_t *co) {
555 lpp_sol_state_t sol_state;
559 ASSERT_OU_AVAIL(co); //See build_clique_st
565 my.nr_2_irn = pmap_create();
566 FIRM_DBG_REGISTER(my.dbg, "firm.be.coilp2");
568 my.normal_colors = bitset_alloca(arch_register_class_n_regs(co->cls));
569 bitset_clear_all(my.normal_colors);
570 arch_put_non_ignore_regs(co->cls, my.normal_colors);
571 my.n_colors = bitset_popcnt(my.normal_colors);
573 ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);
575 sol_state = ilp_go(ienv);
577 pmap_destroy(my.nr_2_irn);
580 return sol_state == lpp_optimal;
585 static inline void only_that_you_can_compile_without_WITH_ILP_defined(void) {
588 #endif /* WITH_ILP */