nsz Git - libfirm/blob - ir/be/becopyilp2.c

   1 /**
   2  * Author:      Daniel Grund
   3  * Date:                28.02.2006
   4  * Copyright:   (c) Universitaet Karlsruhe
   5  * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
   6  *
   7  *
   8  * ILP formalization using G=(V, E, Q):
   9  *  - 2 class of variables: coloring vars x_ic   and   equal color vars y_ij
  10  *  - Path constraints
  11  *  - Clique-star constraints
  12  *
  13  *
  14  *      \min \sum_{ (i,j) \in Q }  w_ij y_ij
  15  *
  16  *              \sum_c x_nc                     =  1                    n \in N, c \in C
  17  *
  18  *              x_nc                            =  0                    n \in N, c \not\in C(n)
  19  *
  20  *              \sum x_nc                       <= 1                    x_nc \in Clique \in AllCliques,  c \in C
  21  *
  22  *              \sum_{e \in p} y_e      >= 1                    p \in P         path constraints
  23  *
  24  *              \sum_{e \in cs} y_e     >= |cs| - 1             cs \in CP       clique-star constraints
  25  *
  26  *              x_nc, y_ij \in N,   w_ij \in R^+
  27  */
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif /* HAVE_CONFIG_H */
  32
  33 #ifdef WITH_ILP
  34
  35 #include <bitset.h>
  36 #include "pdeq.h"
  37
  38 #include "irtools.h"
  39 #include "irgwalk.h"
  40 #include "becopyilp_t.h"
  41 #include "beifg_t.h"
  42 #include "besched_t.h"
  43
  44 #define DEBUG_LVL 1
  45
  46 typedef struct _local_env_t {
  47         firm_dbg_module_t *dbg;
  48         double time_limit;
  49         int first_x_var, last_x_var;
  50         pmap *nr_2_irn;
  51 } local_env_t;
  52
  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);
  56         bitset_t *colors;
  57         ir_node *irn;
  58         char buf[16];
  59
  60         colors = bitset_alloca(arch_register_class_n_regs(ienv->co->cls));
  61
  62         be_ifg_foreach_node(ifg, iter, irn)
  63                 if (!sr_is_removed(ienv->sr, irn)) {
  64                         int col, cst_idx;
  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;
  69
  70                         pmap_insert(lenv->nr_2_irn, INT_TO_PTR(node_nr), irn);
  71
  72                         arch_get_register_req(ienv->co->aenv, &req, irn, -1);
  73
  74                         /* get assignable colors */
  75                         if (arch_register_req_is(&req, limited))
  76                                 req.limited(req.limited_env, colors);
  77                         else
  78                                 arch_put_non_ignore_regs(ienv->co->aenv, req.cls, colors);
  79
  80                         /* add the coloring constraint */
  81                         cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 1.0);
  82
  83                         bitset_foreach(colors, col) {
  84                                 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
  85                                 lpp_set_start_value(ienv->lp, var_idx, (col == curr_node_color) ? 1.0 : 0.0);
  86                                 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
  87
  88                                 lenv->last_x_var = var_idx;
  89                                 if (lenv->first_x_var == -1)
  90                                         lenv->first_x_var = var_idx;
  91                         }
  92
  93                         /* add register constraint constraints */
  94                         bitset_foreach_clear(colors, col) {
  95                                 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 0.0);
  96                                 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
  97                                 lpp_set_start_value(ienv->lp, var_idx, 0.0);
  98                                 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
  99
 100                                 lenv->last_x_var = var_idx;
 101                         }
 102                 }
 103 }
 104
 105 static void build_interference_cstr(ilp_env_t *ienv) {
 106         lpp_t *lpp = ienv->lp;
 107         be_ifg_t *ifg = ienv->co->cenv->ifg;
 108         int n_colors = arch_register_class_n_regs(ienv->co->cls);
 109         int i, col;
 110
 111         void *iter = be_ifg_cliques_iter_alloca(ifg);
 112         ir_node **clique = alloca(sizeof(*clique) * n_colors);
 113         int size;
 114
 115         char buf[16];
 116
 117         /* for each maximal clique */
 118         be_ifg_foreach_clique(ifg, iter, clique, &size) {
 119                 int realsize = 0;
 120
 121                 for (i=0; i<size; ++i)
 122                         if (!sr_is_removed(ienv->sr, clique[i]))
 123                                 ++realsize;
 124
 125                 if (realsize < 2)
 126                         continue;
 127
 128                 /* for all colors */
 129                 for (col=0; col<n_colors; ++col) {
 130                         int cst_idx = lpp_add_cst(lpp, NULL, lpp_less, 1.0);
 131
 132                         /* for each member of this clique */
 133                         for (i=0; i<size; ++i) {
 134                                 ir_node *irn = clique[i];
 135
 136                                 if (!sr_is_removed(ienv->sr, irn)) {
 137                                         int var_idx = lpp_get_var_idx(lpp, name_cdd(buf, 'x', (int)get_irn_node_nr(irn), col));
 138                                         lpp_set_factor_fast(lpp, cst_idx, var_idx, 1);
 139                                 }
 140                         }
 141                 }
 142         }
 143 }
 144
 145
 146 /**
 147  * TODO: Remove the dependency of the opt-units data structure
 148  *       by walking over all affinity edges. Graph structure
 149  *       does not provide this walker, yet.
 150  */
 151 static void build_affinity_cstr(ilp_env_t *ienv) {
 152         unit_t *curr;
 153         int n_colors = arch_register_class_n_regs(ienv->co->cls);
 154
 155         /* for all optimization units */
 156         list_for_each_entry(unit_t, curr, &ienv->co->units, units) {
 157                 ir_node *root, *arg;
 158                 int root_nr, arg_nr, i, col, y_idx, root_idx, arg_idx;
 159                 char buf[16];
 160                 int root_col, arg_col;
 161
 162                 root = curr->nodes[0];
 163                 root_nr = (int) get_irn_node_nr(root);
 164                 root_col = get_irn_col(ienv->co, root);
 165
 166                 for (i = 1; i < curr->node_count; ++i) {
 167                         arg = curr->nodes[i];
 168                         arg_nr = (int) get_irn_node_nr(arg);
 169                         arg_col = get_irn_col(ienv->co, arg);
 170
 171                         /* add a new affinity variable */
 172                         y_idx = lpp_add_var(ienv->lp, name_cdd_sorted(buf, 'y', root_nr, arg_nr), lpp_binary, curr->costs[i]);
 173                         lpp_set_start_value(ienv->lp, y_idx, (root_col==arg_col) ? 0.0 : 1.0);
 174
 175                         /* add constraints relating the affinity var to the color vars */
 176                         for (col=0; col<n_colors; ++col) {
 177                                 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_less, 0.0);
 178                                 root_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', root_nr, col));
 179                                 arg_idx  = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', arg_nr,  col));
 180
 181                                 lpp_set_factor_fast(ienv->lp, cst_idx, root_idx,  1.0);
 182                                 lpp_set_factor_fast(ienv->lp, cst_idx, arg_idx,  -1.0);
 183                                 lpp_set_factor_fast(ienv->lp, cst_idx, y_idx, -1.0);
 184                         }
 185                 }
 186         }
 187 }
 188
 189 /**
 190  * Helping stuff for build_clique_star_cstr
 191  */
 192 typedef struct _edge_t {
 193         ir_node *n1, *n2;
 194 } edge_t;
 195
 196 static int compare_edge_t(const void *k1, const void *k2, size_t size) {
 197         const edge_t *e1 = k1;
 198         const edge_t *e2 = k2;
 199
 200         return ! (e1->n1 == e2->n1   &&   e1->n2 == e2->n2);
 201 }
 202
 203 #define HASH_EDGE(e) (HASH_PTR((e)->n1) ^ HASH_PTR((e)->n2))
 204
 205 static INLINE edge_t *add_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
 206         edge_t new_edge;
 207
 208         if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
 209                 new_edge.n1 = n1;
 210                 new_edge.n2 = n2;
 211         } else {
 212                 new_edge.n1 = n2;
 213                 new_edge.n2 = n1;
 214         }
 215         (*counter)++;
 216         return set_insert(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
 217 }
 218
 219 static INLINE edge_t *find_edge(set *edges, ir_node *n1, ir_node *n2) {
 220         edge_t new_edge;
 221
 222         if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
 223                 new_edge.n1 = n1;
 224                 new_edge.n2 = n2;
 225         } else {
 226                 new_edge.n1 = n2;
 227                 new_edge.n2 = n1;
 228         }
 229         return set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
 230 }
 231
 232 static INLINE void remove_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
 233         edge_t new_edge, *e;
 234
 235         if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
 236                 new_edge.n1 = n1;
 237                 new_edge.n2 = n2;
 238         } else {
 239                 new_edge.n1 = n2;
 240                 new_edge.n2 = n1;
 241         }
 242         e = set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
 243         if (e) {
 244                 e->n1 = NULL;
 245                 e->n2 = NULL;
 246                 (*counter)--;
 247         }
 248 }
 249
 250 #define pset_foreach(pset, irn)  for(irn=pset_first(pset); irn; irn=pset_next(pset))
 251
 252 /**
 253  * Search for an interference clique and an external node
 254  * with affinity edges to all nodes of the clique.
 255  * At most 1 node of the clique can be colored equally with the external node.
 256  */
 257 static void build_clique_star_cstr(ilp_env_t *ienv) {
 258         affinity_node_t *aff;
 259
 260         /* for each node with affinity edges */
 261         co_gs_foreach_aff_node(ienv->co, aff) {
 262                 struct obstack ob;
 263                 neighb_t *nbr;
 264                 ir_node *center = aff->irn;
 265                 ir_node **nodes;
 266                 set *edges;
 267                 int i, o, n_nodes, n_edges;
 268
 269                 obstack_init(&ob);
 270                 edges = new_set(compare_edge_t, 8);
 271
 272                 /* get all affinity neighbours */
 273                 n_nodes = 0;
 274                 co_gs_foreach_neighb(aff, nbr) {
 275                         obstack_ptr_grow(&ob, nbr->irn);
 276                         ++n_nodes;
 277                 }
 278                 nodes = obstack_finish(&ob);
 279
 280                 /* get all interference edges between these */
 281                 n_edges = 0;
 282                 for (i=0; i<n_nodes; ++i)
 283                         for (o=0; o<i; ++o)
 284                                 if (be_ifg_connected(ienv->co->cenv->ifg, nodes[i], nodes[o]))
 285                                         add_edge(edges, nodes[i], nodes[o], &n_edges);
 286
 287                 /* cover all these interference edges with maximal cliques */
 288                 while (n_edges) {
 289                         edge_t *e;
 290                         pset *clique = pset_new_ptr(8);
 291                         int growed;
 292
 293                         /* get 2 starting nodes to form a clique */
 294                         for (e=set_first(edges); !e->n1; e=set_next(edges))
 295                                 /*nothing*/ ;
 296
 297                         pset_insert_ptr(clique, e->n1);
 298                         pset_insert_ptr(clique, e->n2);
 299                         remove_edge(edges, e->n1, e->n2, &n_edges);
 300
 301                         /* while the clique is growing */
 302                         do {
 303                                 growed = 0;
 304
 305                                 /* search for a candidate to extend the clique */
 306                                 for (i=0; i<n_nodes; ++i) {
 307                                         ir_node *member, *cand = nodes[i];
 308                                         int is_cand;
 309
 310                                         /* if its already in the clique try the next */
 311                                         if (pset_find_ptr(clique, cand))
 312                                                 continue;
 313
 314                                         /* are there all necessary interferences? */
 315                                         is_cand = 1;
 316                                         pset_foreach(clique, member) {
 317                                                 if (!find_edge(edges, cand, member)) {
 318                                                         is_cand = 0;
 319                                                         pset_break(clique);
 320                                                         break;
 321                                                 }
 322                                         }
 323
 324                                         /* now we know if we have a clique extender */
 325                                         if (is_cand) {
 326                                                 /* first remove all covered edges */
 327                                                 pset_foreach(clique, member)
 328                                                         remove_edge(edges, cand, member, &n_edges);
 329
 330                                                 /* insert into clique */
 331                                                 pset_insert_ptr(clique, cand);
 332                                                 growed = 1;
 333                                                 break;
 334                                         }
 335                                 }
 336                         } while (growed);
 337
 338                         /* now the clique is maximal. Finally add the constraint */
 339                         {
 340                                 ir_node *member;
 341                                 int var_idx, cst_idx, center_nr, member_nr;
 342                                 char buf[16];
 343
 344                                 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, pset_count(clique)-1);
 345                                 center_nr = get_irn_node_nr(center);
 346
 347                                 pset_foreach(clique, member) {
 348                                         member_nr = get_irn_node_nr(member);
 349                                         var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', center_nr, member_nr));
 350                                         lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
 351                                 }
 352                         }
 353
 354                         del_pset(clique);
 355                 }
 356
 357                 del_set(edges);
 358                 obstack_free(&ob, NULL);
 359         }
 360 }
 361
 362
 363 static void extend_path(ilp_env_t *ienv, pdeq *path, ir_node *irn) {
 364         be_ifg_t *ifg = ienv->co->cenv->ifg;
 365         int i, len;
 366         ir_node **curr_path;
 367         affinity_node_t *aff;
 368         neighb_t *nbr;
 369
 370         /* do not walk backwards or in circles */
 371         if (pdeq_contains(path, irn))
 372                 return;
 373
 374         /* insert the new irn */
 375         pdeq_putr(path, irn);
 376
 377
 378
 379         /* check for forbidden interferences */
 380         len = pdeq_len(path);
 381         curr_path = alloca(len * sizeof(*curr_path));
 382         pdeq_copyl(path, (const void **)curr_path);
 383
 384         for (i=1; i<len; ++i)
 385                 if (be_ifg_connected(ifg, irn, curr_path[i]))
 386                         goto end;
 387
 388
 389
 390         /* check for terminating interference */
 391         if (be_ifg_connected(ifg, irn, curr_path[0])) {
 392
 393                 /* One node is not a path. */
 394                 /* And a path of length 2 is covered by a clique star constraint. */
 395                 if (len > 2) {
 396                         /* finally build the constraint */
 397                         int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, 1.0);
 398                         for (i=1; i<len; ++i) {
 399                                 char buf[16];
 400                                 int nr_1    = get_irn_node_nr(curr_path[i-1]);
 401                                 int nr_2    = get_irn_node_nr(curr_path[i]);
 402                                 int var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', nr_1, nr_2));
 403                                 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
 404                         }
 405                 }
 406
 407                 /* this path cannot be extended anymore */
 408                 goto end;
 409         }
 410
 411
 412
 413         /* recursively extend the path */
 414         aff = get_affinity_info(ienv->co, irn);
 415         co_gs_foreach_neighb(aff, nbr)
 416                 extend_path(ienv, path, nbr->irn);
 417
 418
 419 end:
 420         /* remove the irn */
 421         pdeq_getr(path);
 422
 423 }
 424
 425 /**
 426  *  Search a path of affinity edges, whose ends are connected
 427  *  by an interference edge and there are no other interference
 428  *  edges in between.
 429  *  Then at least one of these affinity edges must break.
 430  */
 431 static void build_path_cstr(ilp_env_t *ienv) {
 432         affinity_node_t *aff_info;
 433
 434         /* for each node with affinity edges */
 435         co_gs_foreach_aff_node(ienv->co, aff_info) {
 436                 pdeq *path = new_pdeq();
 437
 438                 extend_path(ienv, path, aff_info->irn);
 439
 440                 del_pdeq(path);
 441         }
 442 }
 443
 444 static void ilp2_build(ilp_env_t *ienv) {
 445         local_env_t *lenv = ienv->env;
 446         int lower_bound;
 447
 448         ienv->lp = new_lpp(ienv->co->name, lpp_minimize);
 449         build_coloring_cstr(ienv);
 450         build_interference_cstr(ienv);
 451         build_affinity_cstr(ienv);
 452         build_clique_star_cstr(ienv);
 453         build_path_cstr(ienv);
 454
 455         lower_bound = co_get_lower_bound(ienv->co) - co_get_inevit_copy_costs(ienv->co);
 456         lpp_set_bound(ienv->lp, lower_bound);
 457         lpp_set_time_limit(ienv->lp, lenv->time_limit);
 458 }
 459
 460 static void ilp2_apply(ilp_env_t *ienv) {
 461         local_env_t *lenv = ienv->env;
 462         double *sol;
 463         lpp_sol_state_t state;
 464         int i, count;
 465
 466         /* first check if there was sth. to optimize */
 467         if (lenv->first_x_var >= 0) {
 468
 469                 count = lenv->last_x_var - lenv->first_x_var + 1;
 470                 sol = xmalloc(count * sizeof(sol[0]));
 471                 state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
 472                 if (state != lpp_optimal) {
 473                         printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
 474                         assert(state >= lpp_feasible && "The solution should at least be feasible!");
 475                 }
 476
 477                 for (i=0; i<count; ++i) {
 478                         int nodenr, color;
 479                         char var_name[16];
 480
 481                         if (sol[i] > 1-EPSILON) { /* split variable name into components */
 482                                 lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
 483
 484                                 if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
 485                                         ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
 486                                         assert(irn && "This node number must be present in the map");
 487
 488                                         set_irn_col(ienv->co, irn, color);
 489                                 } else
 490                                         assert(0 && "This should be a x-var");
 491                         }
 492                 }
 493         }
 494
 495 #ifdef COPYOPT_STAT
 496         /* TODO adapt to multiple possible ILPs */
 497         copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp)));  //now we have ms
 498         copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
 499         copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
 500         copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
 501 #endif
 502 }
 503
 504 int co_solve_ilp2(copy_opt_t *co, double time_limit) {
 505         lpp_sol_state_t sol_state;
 506         ilp_env_t *ienv;
 507         local_env_t my;
 508
 509         ASSERT_OU_AVAIL(co); //See build_clique_st
 510         ASSERT_GS_AVAIL(co);
 511
 512         my.time_limit  = time_limit;
 513         my.first_x_var = -1;
 514         my.last_x_var  = -1;
 515         my.nr_2_irn    = pmap_create();
 516         FIRM_DBG_REGISTER(my.dbg, "firm.be.coilp2");
 517
 518         ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);
 519
 520         sol_state = ilp_go(ienv);
 521
 522         pmap_destroy(my.nr_2_irn);
 523         free_ilp_env(ienv);
 524
 525         return sol_state == lpp_optimal;
 526 }
 527
 528 #else /* WITH_ILP */
 529
 530 static void only_that_you_can_compile_without_WITH_ILP_defined(void) {
 531 }
 532
 533 #endif /* WITH_ILP */