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 "irtools.h"
  36 #include "irgwalk.h"
  37 #include "becopyilp_t.h"
  38 #include "beifg_t.h"
  39 #include "besched_t.h"
  40
  41 #define DEBUG_LVL 1
  42
  43 typedef struct _local_env_t {
  44         firm_dbg_module_t *dbg;
  45         double time_limit;
  46         int first_x_var, last_x_var;
  47         pmap *nr_2_irn;
  48 } local_env_t;
  49
  50 static void build_coloring_cstr(ilp_env_t *ienv) {
  51         be_ifg_t *ifg = ienv->co->cenv->ifg;
  52         void *iter = be_ifg_nodes_iter_alloca(ifg);
  53         bitset_t *colors;
  54         ir_node *irn;
  55         char buf[16];
  56
  57         colors = bitset_alloca(arch_register_class_n_regs(ienv->co->cls));
  58
  59         be_ifg_foreach_node(ifg, iter, irn)
  60                 if (!sr_is_removed(ienv->sr, irn)) {
  61                         int col, cst_idx;
  62                         arch_register_req_t req;
  63                         int curr_node_color = get_irn_col(ienv->co, irn);
  64                         int node_nr = (int)get_irn_node_nr(irn);
  65                         local_env_t *lenv = ienv->env;
  66
  67                         pmap_insert(lenv->nr_2_irn, INT_TO_PTR(node_nr), irn);
  68
  69                         arch_get_register_req(ienv->co->aenv, &req, irn, -1);
  70
  71                         /* get assignable colors */
  72                         if (arch_register_req_is(&req, limited))
  73                                 req.limited(req.limited_env, colors);
  74                         else
  75                                 arch_put_non_ignore_regs(ienv->co->aenv, req.cls, colors);
  76
  77                         /* add the coloring constraint */
  78                         cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 1.0);
  79
  80                         bitset_foreach(colors, col) {
  81                                 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
  82                                 lpp_set_start_value(ienv->lp, var_idx, (col == curr_node_color) ? 1.0 : 0.0);
  83                                 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
  84
  85                                 lenv->last_x_var = var_idx;
  86                                 if (lenv->first_x_var == -1)
  87                                         lenv->first_x_var = var_idx;
  88                         }
  89
  90                         /* add register constraint constraints */
  91                         bitset_foreach_clear(colors, col) {
  92                                 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 0.0);
  93                                 int var_idx = lpp_add_var(ienv->lp, name_cdd(buf, 'x', node_nr, col), lpp_binary, 0.0);
  94                                 lpp_set_start_value(ienv->lp, var_idx, 0.0);
  95                                 lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
  96
  97                                 lenv->last_x_var = var_idx;
  98                         }
  99                 }
 100 }
 101
 102 static void build_interference_cstr(ilp_env_t *ienv) {
 103         lpp_t *lpp = ienv->lp;
 104         be_ifg_t *ifg = ienv->co->cenv->ifg;
 105         int n_colors = arch_register_class_n_regs(ienv->co->cls);
 106         int i, col;
 107
 108         void *iter = be_ifg_cliques_iter_alloca(ifg);
 109         ir_node **clique = alloca(sizeof(*clique) * n_colors);
 110         int size;
 111
 112         char buf[16];
 113
 114         /* for each maximal clique */
 115         be_ifg_foreach_clique(ifg, iter, clique, &size) {
 116
 117                 if (size < 2)
 118                         continue;
 119
 120                 /* for all colors */
 121                 for (col=0; col<n_colors; ++col) {
 122                         int cst_idx = lpp_add_cst(lpp, NULL, lpp_less, 1.0);
 123
 124                         /* for each member of this clique */
 125                         for (i=0; i<size; ++i) {
 126                                 ir_node *irn = clique[i];
 127
 128                                 if (!sr_is_removed(ienv->sr, irn)) {
 129                                         int var_idx = lpp_get_var_idx(lpp, name_cdd(buf, 'x', (int)get_irn_node_nr(irn), col));
 130                                         lpp_set_factor_fast(lpp, cst_idx, var_idx, 1);
 131                                 }
 132                         }
 133                 }
 134         }
 135 }
 136
 137 static void build_affinity_cstr(ilp_env_t *ienv) {
 138         unit_t *curr;
 139         int n_colors = arch_register_class_n_regs(ienv->co->cls);
 140
 141         /* for all optimization units */
 142         list_for_each_entry(unit_t, curr, &ienv->co->units, units) {
 143                 ir_node *root, *arg;
 144                 int root_nr, arg_nr, i, col, y_idx, root_idx, arg_idx;
 145                 char buf[16];
 146                 int root_col, arg_col;
 147
 148                 root = curr->nodes[0];
 149                 root_nr = (int) get_irn_node_nr(root);
 150                 root_col = get_irn_col(ienv->co, root);
 151
 152                 for (i = 1; i < curr->node_count; ++i) {
 153                         arg = curr->nodes[i];
 154                         arg_nr = (int) get_irn_node_nr(arg);
 155                         arg_col = get_irn_col(ienv->co, arg);
 156
 157                         /* add a new affinity variable */
 158                         y_idx = lpp_add_var(ienv->lp, name_cdd_sorted(buf, 'y', root_nr, arg_nr), lpp_binary, curr->costs[i]);
 159                         lpp_set_start_value(ienv->lp, y_idx, (root_col==arg_col) ? 0.0 : 1.0);
 160
 161                         /* add constraints relating the affinity var to the color vars */
 162                         for (col=0; col<n_colors; ++col) {
 163                                 int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_less, 0.0);
 164                                 root_idx = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', root_nr, col));
 165                                 arg_idx  = lpp_get_var_idx(ienv->lp, name_cdd(buf, 'x', arg_nr,  col));
 166
 167                                 lpp_set_factor_fast(ienv->lp, cst_idx, root_idx,  1.0);
 168                                 lpp_set_factor_fast(ienv->lp, cst_idx, arg_idx,  -1.0);
 169                                 lpp_set_factor_fast(ienv->lp, cst_idx, root_idx, -1.0);
 170                         }
 171                 }
 172         }
 173 }
 174
 175 /**
 176  * Helping stuff for build_clique_star_cstr
 177  */
 178 typedef struct _edge_t {
 179         ir_node *n1, *n2;
 180 } edge_t;
 181
 182 static int compare_edge_t(const void *k1, const void *k2, size_t size) {
 183         const edge_t *e1 = k1;
 184         const edge_t *e2 = k2;
 185
 186         return ! (e1->n1 == e2->n1   &&   e1->n2 == e2->n2);
 187 }
 188
 189 #define HASH_EDGE(e) (HASH_PTR((e)->n1) ^ HASH_PTR((e)->n2))
 190
 191 static INLINE edge_t *add_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
 192         edge_t new_edge;
 193
 194         if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
 195                 new_edge.n1 = n1;
 196                 new_edge.n2 = n2;
 197         } else {
 198                 new_edge.n1 = n2;
 199                 new_edge.n2 = n1;
 200         }
 201         *counter++;
 202         return set_insert(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
 203 }
 204
 205 static INLINE edge_t *find_edge(set *edges, ir_node *n1, ir_node *n2) {
 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         return set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
 216 }
 217
 218 static INLINE void remove_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
 219         edge_t new_edge, *e;
 220
 221         if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
 222                 new_edge.n1 = n1;
 223                 new_edge.n2 = n2;
 224         } else {
 225                 new_edge.n1 = n2;
 226                 new_edge.n2 = n1;
 227         }
 228         e = set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
 229         if (e) {
 230                 e->n1 = NULL;
 231                 e->n2 = NULL;
 232                 *counter--;
 233         }
 234 }
 235
 236 #define pset_foreach(pset, irn)  for(irn=pset_first(pset); irn; irn=pset_next(pset))
 237
 238 /**
 239  * Search for an interference clique and an external node
 240  * with affinity edges to all nodes of the clique.
 241  * At most 1 node of the clique can be colored equally with the external node.
 242  */
 243 static void build_clique_star_cstr(ilp_env_t *ienv) {
 244         node_t *node;
 245
 246         /* for each node with affinity edges */
 247         co_gs_foreach_node(ienv->co, node) {
 248                 struct obstack ob;
 249                 neighb_t *nbr;
 250                 ir_node *center = node->irn;
 251                 ir_node **nodes;
 252                 set *edges;
 253                 int i, o, n_nodes, n_edges;
 254
 255                 obstack_init(&ob);
 256                 edges = new_set(compare_edge_t, 8);
 257
 258                 /* get all affinity neighbours */
 259                 n_nodes = 0;
 260                 co_gs_foreach_neighb(node, nbr) {
 261                         obstack_ptr_grow(&ob, nbr->irn);
 262                         ++n_nodes;
 263                 }
 264                 nodes = obstack_finish(&ob);
 265
 266                 /* get all interference edges between these */
 267                 n_edges = 0;
 268                 for (i=0; i<n_nodes; ++i)
 269                         for (o=0; o<i; ++o)
 270                                 if (be_ifg_connected(ienv->co->cenv->ifg, nodes[i], nodes[o]))
 271                                         add_edge(edges, nodes[i], nodes[o], &n_edges);
 272
 273                 /* cover all these interference edges with maximal cliques */
 274                 while (n_edges) {
 275                         edge_t *e;
 276                         pset *clique = pset_new_ptr(8);
 277                         int growed;
 278
 279                         /* get 2 starting nodes to form a clique */
 280                         for (e=set_first(edges); !e->n1; e=set_next(edges))
 281                                 /*nothing*/ ;
 282
 283                         remove_edge(edges, e->n1, e->n2, &n_edges);
 284                         pset_insert_ptr(clique, e->n1);
 285                         pset_insert_ptr(clique, e->n2);
 286
 287                         /* while the clique is growing */
 288                         do {
 289                                 growed = 0;
 290
 291                                 /* search for a candidate to extend the clique */
 292                                 for (i=0; i<n_nodes; ++i) {
 293                                         ir_node *member, *cand = nodes[i];
 294                                         int is_cand;
 295
 296                                         /* if its already in the clique try the next */
 297                                         if (pset_find_ptr(clique, cand))
 298                                                 continue;
 299
 300                                         /* are there all necessary interferences? */
 301                                         is_cand = 1;
 302                                         pset_foreach(clique, member) {
 303                                                 if (!find_edge(edges, cand, member)) {
 304                                                         is_cand = 0;
 305                                                         pset_break(clique);
 306                                                         break;
 307                                                 }
 308                                         }
 309
 310                                         /* now we know if we have a clique extender */
 311                                         if (is_cand) {
 312                                                 /* first remove all covered edges */
 313                                                 pset_foreach(clique, member)
 314                                                         remove_edge(edges, cand, member, &n_edges);
 315
 316                                                 /* insert into clique */
 317                                                 pset_insert_ptr(clique, cand);
 318                                                 growed = 1;
 319                                                 break;
 320                                         }
 321                                 }
 322                         } while (growed);
 323
 324                         /* now the clique is maximal. Finally add the constraint */
 325                         {
 326                                 ir_node *member;
 327                                 int var_idx, cst_idx, center_nr, member_nr;
 328                                 char buf[16];
 329
 330                                 cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, pset_count(clique)-1);
 331                                 center_nr = get_irn_node_nr(center);
 332
 333                                 pset_foreach(clique, member) {
 334                                         member_nr = get_irn_node_nr(member);
 335                                         var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', center_nr, member_nr));
 336                                         lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
 337                                 }
 338                         }
 339
 340                         del_pset(clique);
 341                 }
 342
 343                 del_set(edges);
 344                 obstack_free(&ob, NULL);
 345         }
 346 }
 347
 348 /**
 349  *
 350  */
 351 static void build_path_cstr(ilp_env_t *ienv) {
 352
 353 }
 354
 355 static void ilp2_build(ilp_env_t *ienv) {
 356         local_env_t *lenv = ienv->env;
 357         int lower_bound;
 358
 359         ienv->lp = new_lpp(ienv->co->name, lpp_minimize);
 360         build_coloring_cstr(ienv);
 361         build_interference_cstr(ienv);
 362         build_affinity_cstr(ienv);
 363         build_clique_star_cstr(ienv);
 364         build_path_cstr(ienv);
 365
 366         lower_bound = co_get_lower_bound(ienv->co) - co_get_inevit_copy_costs(ienv->co);
 367         lpp_set_bound(ienv->lp, lower_bound);
 368         lpp_set_time_limit(ienv->lp, lenv->time_limit);
 369 }
 370
 371 static void ilp2_apply(ilp_env_t *ienv) {
 372         local_env_t *lenv = ienv->env;
 373         double *sol;
 374         lpp_sol_state_t state;
 375         int i, count;
 376
 377         count = lenv->last_x_var - lenv->first_x_var + 1;
 378         sol = xmalloc(count * sizeof(sol[0]));
 379         state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
 380         if (state != lpp_optimal) {
 381                 printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
 382                 assert(state >= lpp_feasible && "The solution should at least be feasible!");
 383         }
 384
 385         for (i=0; i<count; ++i) {
 386                 int nodenr, color;
 387                 char var_name[16];
 388
 389                 if (sol[i] > 1-EPSILON) { /* split variable name into components */
 390                         lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
 391
 392                         if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
 393                                 ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
 394                                 assert(irn && "This node number must be present in the map");
 395
 396                                 set_irn_col(ienv->co, irn, color);
 397                         } else
 398                                 assert(0 && "This should be a x-var");
 399                 }
 400         }
 401
 402 #ifdef COPYOPT_STAT
 403         /* TODO adapt to multiple possible ILPs */
 404         copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp)));  //now we have ms
 405         copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
 406         copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
 407         copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
 408 #endif
 409 }
 410
 411 int co_solve_ilp2(copy_opt_t *co, double time_limit) {
 412         lpp_sol_state_t sol_state;
 413         ilp_env_t *ienv;
 414         local_env_t my;
 415
 416         my.time_limit  = time_limit;
 417         my.first_x_var = -1;
 418         my.last_x_var  = -1;
 419         my.nr_2_irn    = pmap_create();
 420         my.dbg         = firm_dbg_register("ir.be.coilp2");
 421         firm_dbg_set_mask(my.dbg, DEBUG_LVL);
 422
 423         ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);
 424
 425         sol_state = ilp_go(ienv);
 426
 427         pmap_destroy(my.nr_2_irn);
 428         free_ilp_env(ienv);
 429
 430         return sol_state == lpp_optimal;
 431 }
 432
 433 #else /* WITH_ILP */
 434
 435 static void only_that_you_can_compile_without_WITH_ILP_defined(void) {
 436 }
 437
 438 #endif /* WITH_ILP */