nsz Git - libfirm/blob - ir/lpp/lpp.c

   1 /*
   2  * Copyright (C) 2005-2011 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  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.
  14  *
  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
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @author  Daniel Grund
  23  */
  24 #include "config.h"
  25
  26 #include <stdlib.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29
  30 #include "assert.h"
  31 #include "obst.h"
  32 #include "hashptr.h"
  33 #include "debug.h"
  34 #include "set.h"
  35
  36 #include "sp_matrix.h"
  37 #include "mps.h"
  38 #include "lpp_t.h"
  39 #include "lpp_comm.h"
  40 #include "lpp_solvers.h"
  41 #include "lpp_net.h"
  42
  43 #define HASH_NAME_T(n) HASH_STR((n)->name, strlen((n)->name))
  44
  45 static firm_dbg_module_t *dbg = NULL;
  46
  47 static inline char *obst_xstrdup(struct obstack *obst, const char *str)
  48 {
  49         return obstack_copy0(obst, str, strlen(str));
  50 }
  51
  52 static int cmp_name_t(const void *x, const void *y, size_t size)
  53 {
  54         const lpp_name_t *n = x;
  55         const lpp_name_t *m = y;
  56         (void)size;
  57         return strcmp(n->name, m->name);
  58 }
  59
  60 /**
  61  * Update statistic information about matrix usage.
  62  */
  63 static void update_stats(lpp_t *lpp)
  64 {
  65         lpp->n_elems    = matrix_get_entries(lpp->m);
  66         lpp->matrix_mem = lpp->n_elems * matrix_get_elem_size();
  67         lpp->density    = (double)lpp->n_elems / (double)(lpp->cst_next * lpp->var_next) * 100.0;
  68 }
  69
  70 lpp_t *lpp_new(const char *name, lpp_opt_t opt_type)
  71 {
  72         return lpp_new_userdef(name, opt_type, 64, 64, 2.0);
  73 }
  74
  75 lpp_t *lpp_new_userdef(const char *name, lpp_opt_t opt_type,
  76                                    int estimated_vars, int estimated_csts,
  77                                    double grow_factor)
  78 {
  79         lpp_t *lpp;
  80         int   idx;
  81
  82         dbg = firm_dbg_register("lpp");
  83         lpp = XMALLOCZ(lpp_t);
  84         obstack_init(&lpp->obst);
  85
  86         lpp->name        = obst_xstrdup(&lpp->obst, name);
  87         lpp->opt_type    = opt_type;
  88         lpp->grow_factor = grow_factor;
  89         lpp->cst2nr      = new_set(cmp_name_t, estimated_csts);
  90         lpp->var2nr      = new_set(cmp_name_t, estimated_vars);
  91         lpp->cst_size    = estimated_csts;
  92         lpp->var_size    = estimated_vars;
  93         lpp->csts        = XMALLOCNZ(lpp_name_t *, estimated_csts);
  94         lpp->vars        = XMALLOCNZ(lpp_name_t *, estimated_vars);
  95         lpp->m           = new_matrix(estimated_csts, estimated_vars);
  96         lpp->emphasis    = lpp_balanced;
  97         idx              = lpp_add_cst(lpp, "obj", lpp_objective, 0);
  98         assert(idx == 0);
  99         idx              = lpp_add_var(lpp, "rhs", lpp_rhs, 0);
 100         assert(idx == 0);
 101
 102         return lpp;
 103 }
 104
 105 void lpp_free_matrix(lpp_t *lpp)
 106 {
 107         del_matrix(lpp->m);
 108         lpp->m = NULL;
 109 }
 110
 111 void lpp_free(lpp_t *lpp)
 112 {
 113         obstack_free(&lpp->obst, NULL);
 114
 115         del_set(lpp->cst2nr);
 116         del_set(lpp->var2nr);
 117
 118         /* matrix might have been already deleted */
 119         if (lpp->m)
 120                 del_matrix(lpp->m);
 121
 122         free(lpp->csts);
 123         free(lpp->vars);
 124
 125         free(lpp);
 126 }
 127
 128 double lpp_get_fix_costs(lpp_t *lpp)
 129 {
 130         return matrix_get(lpp->m, 0, 0);
 131 }
 132
 133 void lpp_set_fix_costs(lpp_t *lpp, double value)
 134 {
 135         matrix_set(lpp->m, 0, 0, value);
 136 }
 137
 138 static int name2nr(set *where, const char *name)
 139 {
 140         lpp_name_t find, *found;
 141         find.name = name;
 142         found = set_find(where, &find, sizeof(find), HASH_NAME_T(&find));
 143         return (found ? found->nr : -1);
 144 }
 145
 146 static int cst_nr(const lpp_t *lpp, const char *name)
 147 {
 148         return name2nr(lpp->cst2nr, name);
 149 }
 150
 151 static int var_nr(const lpp_t *lpp, const char *name)
 152 {
 153         return name2nr(lpp->var2nr, name);
 154 }
 155
 156 static inline char *get_next_name(lpp_t *lpp)
 157 {
 158         char *res = obstack_alloc(&lpp->obst, 12);
 159         snprintf(res, 12, "_%u", lpp->next_name_number++);
 160         return res;
 161 }
 162
 163 int lpp_add_cst(lpp_t *lpp, const char *cst_name, lpp_cst_t cst_type, double rhs)
 164 {
 165         lpp_name_t n, *inner;
 166
 167         DBG((dbg, LEVEL_2, "%s %d %g\n", cst_name, cst_type, rhs));
 168
 169         if (cst_name && cst_name[0] == '_')
 170                 return ERR_NAME_NOT_ALLOWED;
 171
 172         if (cst_name)
 173                 n.name = obst_xstrdup(&lpp->obst, cst_name);
 174         else
 175                 n.name = get_next_name(lpp);
 176
 177         n.nr  = -1;
 178         inner = set_insert(lpp->cst2nr, &n, sizeof(n), HASH_NAME_T(&n));
 179         assert(inner);
 180
 181         if (inner->nr == -1) {
 182                 inner->value_kind    = lpp_none;
 183                 inner->value         = 0.0;
 184                 inner->nr            = lpp->cst_next;
 185                 inner->type.cst_type = cst_type;
 186
 187                 if (lpp->cst_next == lpp->cst_size) {
 188                         lpp->cst_size = (int)((double)lpp->cst_size * lpp->grow_factor) + 1;
 189                         lpp->csts     = XREALLOC(lpp->csts, lpp_name_t *, lpp->cst_size);
 190                 }
 191
 192                 lpp->csts[lpp->cst_next] = inner;
 193                 lpp->cst_next++;
 194                 matrix_set(lpp->m, inner->nr, 0, rhs);
 195         }
 196
 197         update_stats(lpp);
 198         return inner->nr;
 199 }
 200
 201 int lpp_add_cst_uniq(lpp_t *lpp, const char *cst_name, lpp_cst_t cst_type, double rhs)
 202 {
 203         if (cst_name) {
 204                 lpp_name_t n;
 205
 206                 n.name = cst_name;
 207                 n.nr   = -1;
 208                 assert(!set_find(lpp->cst2nr, &n, sizeof(n), HASH_NAME_T(&n)) &&
 209                     "constraint already exists");
 210         }
 211         return lpp_add_cst(lpp, cst_name, cst_type, rhs);
 212 }
 213
 214 int lpp_get_cst_idx(lpp_t *lpp, const char *cst_name)
 215 {
 216         DBG((dbg, LEVEL_2, "%s --> %d\n", cst_name, cst_nr(lpp, cst_name)));
 217         return cst_nr(lpp, cst_name);
 218 }
 219
 220 void lpp_get_cst_name(lpp_t *lpp, int index, char *buf, size_t buf_size)
 221 {
 222         DBG((dbg, LEVEL_2, "%d --> %s\n", index, lpp->csts[index]->name));
 223         strncpy(buf, lpp->csts[index]->name, buf_size);
 224 }
 225
 226 int lpp_add_var_default(lpp_t *lpp, const char *var_name, lpp_var_t var_type, double obj, double startval)
 227 {
 228         int val;
 229
 230         val = lpp_add_var(lpp, var_name, var_type, obj);
 231         lpp_set_start_value(lpp, val, startval);
 232
 233         return val;
 234 }
 235
 236 int lpp_add_var(lpp_t *lpp, const char *var_name, lpp_var_t var_type, double obj)
 237 {
 238         lpp_name_t n, *inner;
 239
 240         DBG((dbg, LEVEL_2, "%s %d %g\n", var_name, var_type, obj));
 241
 242         assert(var_type != lpp_invalid && "invalid is for internal use only");
 243
 244         if (var_name && var_name[0] == '_')
 245                 return ERR_NAME_NOT_ALLOWED;
 246
 247         if (var_name)
 248                 n.name = obst_xstrdup(&lpp->obst, var_name);
 249         else
 250                 n.name = get_next_name(lpp);
 251
 252         n.nr  = -1;
 253         inner = set_insert(lpp->var2nr, &n, sizeof(n), HASH_NAME_T(&n));
 254         assert(inner);
 255
 256         if (inner->nr == -1) {
 257                 inner->nr            = lpp->var_next;
 258                 inner->value_kind    = 0;
 259                 inner->value         = 0;
 260                 inner->type.var_type = var_type;
 261
 262                 if (lpp->var_next == lpp->var_size) {
 263                         lpp->var_size = (int)((double)lpp->var_size * lpp->grow_factor) + 1;
 264                         lpp->vars     = XREALLOC(lpp->vars, lpp_name_t *, lpp->var_size);
 265                 }
 266
 267                 lpp->vars[lpp->var_next] = inner;
 268                 lpp->var_next++;
 269                 matrix_set(lpp->m, 0, inner->nr, obj);
 270         }
 271
 272         update_stats(lpp);
 273         return inner->nr;
 274 }
 275
 276 int lpp_get_var_idx(lpp_t *lpp, const char *var_name)
 277 {
 278         DBG((dbg, LEVEL_2, "%s --> %d\n", var_name, var_nr(lpp, var_name)));
 279         return var_nr(lpp, var_name);
 280 }
 281
 282 void lpp_get_var_name(lpp_t *lpp, int index, char *buf, size_t buf_size)
 283 {
 284         DBG((dbg, LEVEL_2, "%d --> %s\n", index, lpp->vars[index]->name));
 285         strncpy(buf, lpp->vars[index]->name, buf_size);
 286 }
 287
 288 int lpp_set_factor(lpp_t *lpp, const char *cst_name, const char *var_name, double value)
 289 {
 290         int cst, var;
 291
 292         cst = cst_nr(lpp, cst_name);
 293         var = var_nr(lpp, var_name);
 294         assert(cst != -1 && var != -1);
 295         DBG((dbg, LEVEL_2, "%s[%d] %s[%d] %g\n", cst_name, cst, var_name, var, value));
 296         matrix_set(lpp->m, cst, var, value);
 297         update_stats(lpp);
 298         return 0;
 299 }
 300
 301 int lpp_set_factor_fast(lpp_t *lpp, int cst_idx, int var_idx, double value)
 302 {
 303         assert(cst_idx >= 0 && var_idx >= 0);
 304         assert(cst_idx < lpp->cst_next && var_idx < lpp->var_next);
 305         DBG((dbg, LEVEL_2, "%s[%d] %s[%d] %g\n", lpp->csts[cst_idx]->name, cst_idx, lpp->vars[var_idx]->name, var_idx, value));
 306         matrix_set(lpp->m, cst_idx, var_idx, value);
 307         update_stats(lpp);
 308         return 0;
 309 }
 310
 311 int lpp_set_factor_fast_bulk(lpp_t *lpp, int cst_idx, int *var_idx, int num_vars, double value)
 312 {
 313         assert(cst_idx >= 0 && cst_idx < lpp->cst_next);
 314         assert(num_vars < lpp->var_next);
 315         DBG((dbg, LEVEL_2, "row %s[%d] %d vars %g\n", lpp->csts[cst_idx]->name, cst_idx, num_vars, value));
 316         matrix_set_row_bulk(lpp->m, cst_idx, var_idx, num_vars, value);
 317         update_stats(lpp);
 318         return 0;
 319 }
 320
 321 void lpp_set_start_value(lpp_t *lpp, int var_idx, double value)
 322 {
 323         assert(var_idx > 0 && var_idx < lpp->var_next);
 324         DBG((dbg, LEVEL_2, "%d %s %g\n", var_idx, lpp->vars[var_idx]->name, value));
 325         lpp->vars[var_idx]->value = value;
 326         lpp->vars[var_idx]->value_kind = lpp_value_start;
 327 }
 328
 329 lpp_sol_state_t lpp_get_solution(lpp_t *lpp, double *values, int begin, int end)
 330 {
 331         int i;
 332
 333         if (lpp->sol_state < lpp_feasible)
 334                 return lpp->sol_state;
 335
 336         /* here we are feasible or optimal */
 337         for (i = 0; i < end - begin + 1; ++i)
 338                 values[i] = lpp->vars[begin + i]->value;
 339
 340         return lpp->sol_state;
 341 }
 342
 343 void lpp_check_startvals(lpp_t *lpp)
 344 {
 345         int cst_idx;
 346
 347         for (cst_idx = 1; cst_idx < lpp->cst_next; ++cst_idx) {
 348                 double     sum     = 0.0;
 349                 lpp_name_t *cst    = lpp->csts[cst_idx];
 350                 double     cst_val = matrix_get(lpp->m, cst_idx, 0);
 351                 int        var_idx;
 352
 353                 for (var_idx = 1; var_idx < lpp->var_next; ++var_idx) {
 354                                 if (lpp->vars[var_idx]->value_kind != lpp_value_start)
 355                                         goto next;
 356
 357                                 sum += lpp->vars[var_idx]->value *
 358                                         matrix_get(lpp->m, cst_idx, var_idx);
 359                 }
 360                 switch(cst->type.cst_type) {
 361                         case lpp_equal:
 362                                 if(sum != cst_val) {
 363                                         fprintf(stderr, "constraint %s unsatisfied: %g != %g\n", cst->name, sum, cst_val);
 364                                 }
 365                                 break;
 366                         case lpp_less_equal:
 367                                 if(sum > cst_val) {
 368                                         fprintf(stderr, "constraint %s unsatisfied: %g >= %g\n", cst->name, sum, cst_val);
 369                                 }
 370                                 break;
 371                         case lpp_greater_equal:
 372                                 if(sum < cst_val) {
 373                                         fprintf(stderr, "constraint %s unsatisfied: %g <= %g\n", cst->name, sum, cst_val);
 374                                 }
 375                                 break;
 376                         default:
 377                                 assert(0 && "unknown constraint type");
 378                 }
 379 next: ;
 380         }
 381 }
 382
 383 void lpp_dump(lpp_t *lpp, const char *filename)
 384 {
 385         FILE *out = fopen(filename, "wt");
 386         mps_write_mps(lpp, s_mps_fixed, out);
 387         fclose(out);
 388 }
 389
 390 void lpp_set_log(lpp_t *lpp, FILE *log)
 391 {
 392         lpp->log = log;
 393 }
 394
 395
 396 static const char *lpp_cst_op_to_str(lpp_cst_t cst)
 397 {
 398         switch(cst) {
 399         case lpp_equal:
 400                 return "=";
 401         case lpp_less_equal:
 402                 return "<=";
 403         case lpp_greater_equal:
 404                 return ">=";
 405         default:
 406                 return "";
 407         }
 408 }
 409
 410 void lpp_dump_plain(lpp_t *lpp, FILE *f)
 411 {
 412         int i;
 413
 414         for(i = 0; i < lpp->cst_next; ++i) {
 415                 const matrix_elem_t *elm;
 416                 lpp_name_t *cst = lpp->csts[i];
 417
 418                 fprintf(f, "%16s: ", cst->name);
 419                 matrix_foreach_in_row(lpp->m, cst->nr, elm) {
 420                         lpp_name_t *var = lpp->vars[elm->col];
 421                         /* TODO Perhaps better a define LPP_COL_RHS */
 422                         if(elm->col > 0)
 423                                 fprintf(f, "%+4.1f*%-16s ", elm->val, var->name);
 424                 }
 425
 426                 fprintf(f, "%3s %+4.1f\n",
 427                                 lpp_cst_op_to_str(cst->type.cst_type), matrix_get(lpp->m, cst->nr, 0));
 428         }
 429 }
 430
 431 /**
 432  * Serialize a lpp to a file descriptor.
 433  * @param comm The file descriptor.
 434  * @param lpp The lpp.
 435  */
 436 void lpp_serialize(lpp_comm_t *comm, const lpp_t *lpp, int with_names)
 437 {
 438         int n, i;
 439
 440         lpp_writel(comm, with_names);
 441         lpp_writel(comm, lpp->cst_next);
 442         lpp_writel(comm, lpp->var_next);
 443         lpp_writel(comm, lpp->opt_type);
 444         lpp_writes(comm, lpp->name);
 445
 446         /* write options */
 447         lpp_writel(comm, lpp->set_bound);
 448         lpp_writed(comm, lpp->bound);
 449         lpp_writed(comm, lpp->time_limit_secs);
 450         lpp_writed(comm, lpp->emphasis);
 451
 452         for(i = 0; i < lpp->cst_next; ++i) {
 453                 lpp_name_t *name = lpp->csts[i];
 454                 lpp_writel(comm, name->nr);
 455                 lpp_writel(comm, name->value_kind);
 456                 lpp_writel(comm, name->type.cst_type);
 457
 458                 if(with_names)
 459                         lpp_writes(comm, name->name);
 460         }
 461
 462         for(i = 0; i < lpp->var_next; ++i) {
 463                 lpp_name_t *name = lpp->vars[i];
 464                 lpp_writel(comm, name->nr);
 465                 lpp_writel(comm, name->value_kind);
 466                 lpp_writel(comm, name->type.var_type);
 467
 468                 if(with_names)
 469                         lpp_writes(comm, name->name);
 470         }
 471
 472         {
 473                 const matrix_elem_t *elm;
 474                 n = 0;
 475
 476                 matrix_foreach(lpp->m, elm)
 477                         n++;
 478
 479                 assert(n == matrix_get_entries(lpp->m));
 480                 lpp_writel(comm, n);
 481                 matrix_foreach(lpp->m, elm) {
 482                         lpp_writel(comm, elm->row);
 483                         lpp_writel(comm, elm->col);
 484                         lpp_writed(comm, elm->val);
 485                 }
 486         }
 487 }
 488
 489 /**
 490  * Deserialize an lpp from a file descriptor.
 491  * @param comm The file descriptor.
 492  * @return The Problem.
 493  */
 494 lpp_t *lpp_deserialize(lpp_comm_t *comm)
 495 {
 496         int i, n;
 497         int with_names;
 498
 499         lpp_t *lpp = XMALLOCZ(lpp_t);
 500
 501         /* read general settings */
 502         with_names    = lpp_readl(comm);
 503         lpp->cst_next = lpp_readl(comm);
 504         lpp->var_next = lpp_readl(comm);
 505         lpp->opt_type = lpp_readl(comm);
 506         lpp->name     = lpp_reads(comm);
 507
 508         /* read options */
 509         lpp->set_bound       = lpp_readl(comm);
 510         lpp->bound           = lpp_readd(comm);
 511         lpp->time_limit_secs = lpp_readd(comm);
 512         lpp->emphasis        = lpp_readd(comm);
 513
 514         lpp->cst_size = lpp->cst_next;
 515         lpp->var_size = lpp->var_next;
 516
 517         lpp->cst2nr   = new_set(cmp_name_t, lpp->cst_next);
 518         lpp->var2nr   = new_set(cmp_name_t, lpp->var_next);
 519
 520         lpp->csts     = XMALLOCNZ(lpp_name_t*, lpp->cst_next);
 521         lpp->vars     = XMALLOCNZ(lpp_name_t*, lpp->var_next);
 522         lpp->m        = new_matrix(lpp->cst_next, lpp->var_next);
 523
 524         for(i = 0; i < lpp->cst_next; ++i) {
 525                 lpp_name_t name, *res;
 526
 527                 name.nr            = lpp_readl(comm);
 528                 name.value_kind    = lpp_readl(comm);
 529                 name.type.cst_type = lpp_readl(comm);
 530
 531                 if(with_names) {
 532                         name.name = lpp_reads(comm);
 533                 } else {
 534                         char* buf = XMALLOCN(char, 32);
 535                         snprintf(buf, 32, "c%d\n", name.nr);
 536                         name.name = buf;
 537                 }
 538
 539                 res = set_insert(lpp->cst2nr, &name, sizeof(name), HASH_NAME_T(&name));
 540                 lpp->csts[name.nr] = res;
 541         }
 542
 543         for(i = 0; i < lpp->var_next; ++i) {
 544                 lpp_name_t name, *res;
 545
 546                 name.nr            = lpp_readl(comm);
 547                 name.value_kind    = lpp_readl(comm);
 548                 name.type.var_type = lpp_readl(comm);
 549
 550                 if(with_names) {
 551                         name.name = lpp_reads(comm);
 552                 } else {
 553                         char* buf = XMALLOCN(char, 32);
 554                         snprintf(buf, 32, "v%d\n", name.nr);
 555                         name.name = buf;
 556                 }
 557
 558                 res = set_insert(lpp->var2nr, &name, sizeof(name), HASH_NAME_T(&name));
 559                 lpp->vars[name.nr] = res;
 560         }
 561
 562         n = lpp_readl(comm);
 563         for(i = 0; i < n; ++i) {
 564                 matrix_elem_t elm;
 565                 elm.row = lpp_readl(comm);
 566                 elm.col = lpp_readl(comm);
 567                 elm.val = lpp_readd(comm);
 568                 matrix_set(lpp->m, elm.row, elm.col, elm.val);
 569         }
 570
 571         return lpp;
 572 }
 573
 574 void lpp_serialize_values(lpp_comm_t *comm, const lpp_t *lpp, lpp_value_kind_t value_kind)
 575 {
 576         int i, n;
 577
 578         for(i = 0, n = 0; i < lpp->var_next; ++i)
 579                 n += lpp->vars[i]->value_kind == value_kind;
 580
 581         /* Write the number of values to expect */
 582         lpp_writel(comm, n);
 583
 584         /* send the values */
 585         for(i = 0, n = lpp->var_next; i < n; ++i) {
 586                 const lpp_name_t *name = lpp->vars[i];
 587                 if(name->value_kind == value_kind) {
 588                         lpp_writel(comm, name->nr);
 589                         lpp_writed(comm, name->value);
 590                 }
 591         }
 592 }
 593
 594 void lpp_deserialize_values(lpp_comm_t *comm, lpp_t *lpp, lpp_value_kind_t value_kind)
 595 {
 596         int i, n;
 597
 598         /* Get the number of values to read */
 599         n = lpp_readl(comm);
 600
 601         for(i = 0; i < n; ++i) {
 602                 int nr = lpp_readl(comm);
 603                 lpp_name_t *name = lpp->vars[nr];
 604
 605                 name->value_kind = value_kind;
 606                 name->value = lpp_readd(comm);
 607         }
 608 }
 609
 610 void lpp_serialize_stats(lpp_comm_t *comm, const lpp_t *lpp)
 611 {
 612         lpp_writel(comm, lpp->sol_state);
 613         lpp_writel(comm, lpp->iterations);
 614         lpp_writed(comm, lpp->sol_time);
 615         lpp_writed(comm, lpp->objval);
 616         lpp_writed(comm, lpp->best_bound);
 617 }
 618
 619 void lpp_deserialize_stats(lpp_comm_t *comm, lpp_t *lpp)
 620 {
 621         lpp->sol_state  = lpp_readl(comm);
 622         lpp->iterations = lpp_readl(comm);
 623         lpp->sol_time   = lpp_readd(comm);
 624         lpp->objval     = lpp_readd(comm);
 625         lpp->best_bound = lpp_readd(comm);
 626 }
 627
 628 void lpp_solve(lpp_t *lpp, const char* host, const char* solver)
 629 {
 630         if (host == NULL || strlen(host) == 0) {
 631                 lpp_solver_func_t* f = lpp_find_solver(solver);
 632                 if (f != NULL)
 633                         f(lpp);
 634         } else {
 635                 lpp_solve_net(lpp, host, solver);
 636         }
 637 }
 638