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 #include "debug.h"
  36
  37 #include "sp_matrix.h"
  38 #include "mps.h"
  39 #include "lpp_t.h"
  40 #include "lpp_comm.h"
  41 #include "lpp_solvers.h"
  42 #include "lpp_net.h"
  43
  44 #define HASH_NAME_T(n) hash_str((n)->name)
  45
  46 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
  47
  48 static inline char *obst_xstrdup(struct obstack *obst, const char *str)
  49 {
  50         return (char*)obstack_copy0(obst, str, strlen(str));
  51 }
  52
  53 static int cmp_name_t(const void *x, const void *y, size_t size)
  54 {
  55         const lpp_name_t *n = (const lpp_name_t*)x;
  56         const lpp_name_t *m = (const lpp_name_t*)y;
  57         (void)size;
  58         return strcmp(n->name, m->name);
  59 }
  60
  61 /**
  62  * Update statistic information about matrix usage.
  63  */
  64 static void update_stats(lpp_t *lpp)
  65 {
  66         lpp->n_elems    = matrix_get_entries(lpp->m);
  67         lpp->matrix_mem = lpp->n_elems * matrix_get_elem_size();
  68         lpp->density    = (double)lpp->n_elems / (double)(lpp->cst_next * lpp->var_next) * 100.0;
  69 }
  70
  71 lpp_t *lpp_new(const char *name, lpp_opt_t opt_type)
  72 {
  73         return lpp_new_userdef(name, opt_type, 64, 64, 2.0);
  74 }
  75
  76 lpp_t *lpp_new_userdef(const char *name, lpp_opt_t opt_type,
  77                                    int estimated_vars, int estimated_csts,
  78                                    double grow_factor)
  79 {
  80         lpp_t *lpp;
  81         int   idx;
  82
  83         DEBUG_ONLY(dbg = firm_dbg_register("lpp");)
  84         lpp = XMALLOCZ(lpp_t);
  85         obstack_init(&lpp->obst);
  86
  87         lpp->name        = obst_xstrdup(&lpp->obst, name);
  88         lpp->opt_type    = opt_type;
  89         lpp->grow_factor = grow_factor;
  90         lpp->cst2nr      = new_set(cmp_name_t, estimated_csts);
  91         lpp->var2nr      = new_set(cmp_name_t, estimated_vars);
  92         lpp->cst_size    = estimated_csts;
  93         lpp->var_size    = estimated_vars;
  94         lpp->csts        = XMALLOCNZ(lpp_name_t *, estimated_csts);
  95         lpp->vars        = XMALLOCNZ(lpp_name_t *, estimated_vars);
  96         lpp->m           = new_matrix(estimated_csts, estimated_vars);
  97         lpp->emphasis    = lpp_balanced;
  98         idx              = lpp_add_cst(lpp, "obj", lpp_objective, 0);
  99         assert(idx == 0);
 100         idx              = lpp_add_var(lpp, "rhs", lpp_rhs, 0);
 101         assert(idx == 0);
 102
 103         return lpp;
 104 }
 105
 106 void lpp_free_matrix(lpp_t *lpp)
 107 {
 108         del_matrix(lpp->m);
 109         lpp->m = NULL;
 110 }
 111
 112 void lpp_free(lpp_t *lpp)
 113 {
 114         obstack_free(&lpp->obst, NULL);
 115
 116         del_set(lpp->cst2nr);
 117         del_set(lpp->var2nr);
 118
 119         /* matrix might have been already deleted */
 120         if (lpp->m)
 121                 del_matrix(lpp->m);
 122
 123         free(lpp->csts);
 124         free(lpp->vars);
 125
 126         free(lpp);
 127 }
 128
 129 double lpp_get_fix_costs(lpp_t *lpp)
 130 {
 131         return matrix_get(lpp->m, 0, 0);
 132 }
 133
 134 void lpp_set_fix_costs(lpp_t *lpp, double value)
 135 {
 136         matrix_set(lpp->m, 0, 0, value);
 137 }
 138
 139 static int name2nr(set *where, const char *name)
 140 {
 141         lpp_name_t find, *found;
 142         find.name = name;
 143         found
 144                 = (lpp_name_t*)set_find(where, &find, sizeof(find), HASH_NAME_T(&find));
 145         return (found ? found->nr : -1);
 146 }
 147
 148 static int cst_nr(const lpp_t *lpp, const char *name)
 149 {
 150         return name2nr(lpp->cst2nr, name);
 151 }
 152
 153 static int var_nr(const lpp_t *lpp, const char *name)
 154 {
 155         return name2nr(lpp->var2nr, name);
 156 }
 157
 158 static inline char *get_next_name(lpp_t *lpp)
 159 {
 160         char *res = OALLOCN(&lpp->obst, char, 12);
 161         snprintf(res, 12, "_%u", lpp->next_name_number++);
 162         return res;
 163 }
 164
 165 int lpp_add_cst(lpp_t *lpp, const char *cst_name, lpp_cst_t cst_type, double rhs)
 166 {
 167         lpp_name_t n, *inner;
 168
 169         DBG((dbg, LEVEL_2, "%s %d %g\n", cst_name, cst_type, rhs));
 170
 171         if (cst_name && cst_name[0] == '_')
 172                 return ERR_NAME_NOT_ALLOWED;
 173
 174         if (cst_name)
 175                 n.name = obst_xstrdup(&lpp->obst, cst_name);
 176         else
 177                 n.name = get_next_name(lpp);
 178
 179         n.nr  = -1;
 180         inner = (lpp_name_t*)set_insert(lpp->cst2nr, &n, sizeof(n), HASH_NAME_T(&n));
 181         assert(inner);
 182
 183         if (inner->nr == -1) {
 184                 inner->value_kind    = lpp_none;
 185                 inner->value         = 0.0;
 186                 inner->nr            = lpp->cst_next;
 187                 inner->type.cst_type = cst_type;
 188
 189                 if (lpp->cst_next == lpp->cst_size) {
 190                         lpp->cst_size = (int)((double)lpp->cst_size * lpp->grow_factor) + 1;
 191                         lpp->csts     = XREALLOC(lpp->csts, lpp_name_t *, lpp->cst_size);
 192                 }
 193
 194                 lpp->csts[lpp->cst_next] = inner;
 195                 lpp->cst_next++;
 196                 matrix_set(lpp->m, inner->nr, 0, rhs);
 197         }
 198
 199         update_stats(lpp);
 200         return inner->nr;
 201 }
 202
 203 int lpp_add_cst_uniq(lpp_t *lpp, const char *cst_name, lpp_cst_t cst_type, double rhs)
 204 {
 205         if (cst_name) {
 206                 lpp_name_t n;
 207
 208                 n.name = cst_name;
 209                 n.nr   = -1;
 210                 assert(!set_find(lpp->cst2nr, &n, sizeof(n), HASH_NAME_T(&n)) &&
 211                     "constraint already exists");
 212         }
 213         return lpp_add_cst(lpp, cst_name, cst_type, rhs);
 214 }
 215
 216 int lpp_get_cst_idx(lpp_t *lpp, const char *cst_name)
 217 {
 218         DBG((dbg, LEVEL_2, "%s --> %d\n", cst_name, cst_nr(lpp, cst_name)));
 219         return cst_nr(lpp, cst_name);
 220 }
 221
 222 void lpp_get_cst_name(lpp_t *lpp, int index, char *buf, size_t buf_size)
 223 {
 224         DBG((dbg, LEVEL_2, "%d --> %s\n", index, lpp->csts[index]->name));
 225         strncpy(buf, lpp->csts[index]->name, buf_size);
 226 }
 227
 228 int lpp_add_var_default(lpp_t *lpp, const char *var_name, lpp_var_t var_type, double obj, double startval)
 229 {
 230         int val;
 231
 232         val = lpp_add_var(lpp, var_name, var_type, obj);
 233         lpp_set_start_value(lpp, val, startval);
 234
 235         return val;
 236 }
 237
 238 int lpp_add_var(lpp_t *lpp, const char *var_name, lpp_var_t var_type, double obj)
 239 {
 240         lpp_name_t n, *inner;
 241
 242         DBG((dbg, LEVEL_2, "%s %d %g\n", var_name, var_type, obj));
 243
 244         assert(var_type != lpp_invalid && "invalid is for internal use only");
 245
 246         if (var_name && var_name[0] == '_')
 247                 return ERR_NAME_NOT_ALLOWED;
 248
 249         if (var_name)
 250                 n.name = obst_xstrdup(&lpp->obst, var_name);
 251         else
 252                 n.name = get_next_name(lpp);
 253
 254         n.nr  = -1;
 255         inner = (lpp_name_t*)set_insert(lpp->var2nr, &n, sizeof(n), HASH_NAME_T(&n));
 256         assert(inner);
 257
 258         if (inner->nr == -1) {
 259                 inner->nr            = lpp->var_next;
 260                 inner->value_kind    = lpp_none;
 261                 inner->value         = 0;
 262                 inner->type.var_type = var_type;
 263
 264                 if (lpp->var_next == lpp->var_size) {
 265                         lpp->var_size = (int)((double)lpp->var_size * lpp->grow_factor) + 1;
 266                         lpp->vars     = XREALLOC(lpp->vars, lpp_name_t *, lpp->var_size);
 267                 }
 268
 269                 lpp->vars[lpp->var_next] = inner;
 270                 lpp->var_next++;
 271                 matrix_set(lpp->m, 0, inner->nr, obj);
 272         }
 273
 274         update_stats(lpp);
 275         return inner->nr;
 276 }
 277
 278 int lpp_get_var_idx(lpp_t *lpp, const char *var_name)
 279 {
 280         DBG((dbg, LEVEL_2, "%s --> %d\n", var_name, var_nr(lpp, var_name)));
 281         return var_nr(lpp, var_name);
 282 }
 283
 284 void lpp_get_var_name(lpp_t *lpp, int index, char *buf, size_t buf_size)
 285 {
 286         DBG((dbg, LEVEL_2, "%d --> %s\n", index, lpp->vars[index]->name));
 287         strncpy(buf, lpp->vars[index]->name, buf_size);
 288 }
 289
 290 int lpp_set_factor(lpp_t *lpp, const char *cst_name, const char *var_name, double value)
 291 {
 292         int cst, var;
 293
 294         cst = cst_nr(lpp, cst_name);
 295         var = var_nr(lpp, var_name);
 296         assert(cst != -1 && var != -1);
 297         DBG((dbg, LEVEL_2, "%s[%d] %s[%d] %g\n", cst_name, cst, var_name, var, value));
 298         matrix_set(lpp->m, cst, var, value);
 299         update_stats(lpp);
 300         return 0;
 301 }
 302
 303 int lpp_set_factor_fast(lpp_t *lpp, int cst_idx, int var_idx, double value)
 304 {
 305         assert(cst_idx >= 0 && var_idx >= 0);
 306         assert(cst_idx < lpp->cst_next && var_idx < lpp->var_next);
 307         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));
 308         matrix_set(lpp->m, cst_idx, var_idx, value);
 309         update_stats(lpp);
 310         return 0;
 311 }
 312
 313 int lpp_set_factor_fast_bulk(lpp_t *lpp, int cst_idx, int *var_idx, int num_vars, double value)
 314 {
 315         assert(cst_idx >= 0 && cst_idx < lpp->cst_next);
 316         assert(num_vars < lpp->var_next);
 317         DBG((dbg, LEVEL_2, "row %s[%d] %d vars %g\n", lpp->csts[cst_idx]->name, cst_idx, num_vars, value));
 318         matrix_set_row_bulk(lpp->m, cst_idx, var_idx, num_vars, value);
 319         update_stats(lpp);
 320         return 0;
 321 }
 322
 323 void lpp_set_start_value(lpp_t *lpp, int var_idx, double value)
 324 {
 325         assert(var_idx > 0 && var_idx < lpp->var_next);
 326         DBG((dbg, LEVEL_2, "%d %s %g\n", var_idx, lpp->vars[var_idx]->name, value));
 327         lpp->vars[var_idx]->value = value;
 328         lpp->vars[var_idx]->value_kind = lpp_value_start;
 329 }
 330
 331 lpp_sol_state_t lpp_get_solution(lpp_t *lpp, double *values, int begin, int end)
 332 {
 333         int i;
 334
 335         if (lpp->sol_state < lpp_feasible)
 336                 return lpp->sol_state;
 337
 338         /* here we are feasible or optimal */
 339         for (i = 0; i < end - begin + 1; ++i)
 340                 values[i] = lpp->vars[begin + i]->value;
 341
 342         return lpp->sol_state;
 343 }
 344
 345 void lpp_check_startvals(lpp_t *lpp)
 346 {
 347         int cst_idx;
 348
 349         for (cst_idx = 1; cst_idx < lpp->cst_next; ++cst_idx) {
 350                 double     sum     = 0.0;
 351                 lpp_name_t *cst    = lpp->csts[cst_idx];
 352                 double     cst_val = matrix_get(lpp->m, cst_idx, 0);
 353                 int        var_idx;
 354
 355                 for (var_idx = 1; var_idx < lpp->var_next; ++var_idx) {
 356                                 if (lpp->vars[var_idx]->value_kind != lpp_value_start)
 357                                         goto next;
 358
 359                                 sum += lpp->vars[var_idx]->value *
 360                                         matrix_get(lpp->m, cst_idx, var_idx);
 361                 }
 362                 switch(cst->type.cst_type) {
 363                         case lpp_equal:
 364                                 if(sum != cst_val) {
 365                                         fprintf(stderr, "constraint %s unsatisfied: %g != %g\n", cst->name, sum, cst_val);
 366                                 }
 367                                 break;
 368                         case lpp_less_equal:
 369                                 if(sum > cst_val) {
 370                                         fprintf(stderr, "constraint %s unsatisfied: %g >= %g\n", cst->name, sum, cst_val);
 371                                 }
 372                                 break;
 373                         case lpp_greater_equal:
 374                                 if(sum < cst_val) {
 375                                         fprintf(stderr, "constraint %s unsatisfied: %g <= %g\n", cst->name, sum, cst_val);
 376                                 }
 377                                 break;
 378                         default:
 379                                 assert(0 && "unknown constraint type");
 380                 }
 381 next: ;
 382         }
 383 }
 384
 385 void lpp_dump(lpp_t *lpp, const char *filename)
 386 {
 387         FILE *out = fopen(filename, "wt");
 388         mps_write_mps(lpp, s_mps_fixed, out);
 389         fclose(out);
 390 }
 391
 392 void lpp_set_log(lpp_t *lpp, FILE *log)
 393 {
 394         lpp->log = log;
 395 }
 396
 397
 398 static const char *lpp_cst_op_to_str(lpp_cst_t cst)
 399 {
 400         switch(cst) {
 401         case lpp_equal:
 402                 return "=";
 403         case lpp_less_equal:
 404                 return "<=";
 405         case lpp_greater_equal:
 406                 return ">=";
 407         default:
 408                 return "";
 409         }
 410 }
 411
 412 void lpp_dump_plain(lpp_t *lpp, FILE *f)
 413 {
 414         int i;
 415
 416         for(i = 0; i < lpp->cst_next; ++i) {
 417                 const matrix_elem_t *elm;
 418                 lpp_name_t *cst = lpp->csts[i];
 419
 420                 fprintf(f, "%16s: ", cst->name);
 421                 matrix_foreach_in_row(lpp->m, cst->nr, elm) {
 422                         lpp_name_t *var = lpp->vars[elm->col];
 423                         /* TODO Perhaps better a define LPP_COL_RHS */
 424                         if(elm->col > 0)
 425                                 fprintf(f, "%+4.1f*%-16s ", elm->val, var->name);
 426                 }
 427
 428                 fprintf(f, "%3s %+4.1f\n",
 429                                 lpp_cst_op_to_str(cst->type.cst_type), matrix_get(lpp->m, cst->nr, 0));
 430         }
 431 }
 432
 433 /**
 434  * Serialize a lpp to a file descriptor.
 435  * @param comm The file descriptor.
 436  * @param lpp The lpp.
 437  */
 438 void lpp_serialize(lpp_comm_t *comm, const lpp_t *lpp, int with_names)
 439 {
 440         int n, i;
 441
 442         lpp_writel(comm, with_names);
 443         lpp_writel(comm, lpp->cst_next);
 444         lpp_writel(comm, lpp->var_next);
 445         lpp_writel(comm, lpp->opt_type);
 446         lpp_writes(comm, lpp->name);
 447
 448         /* write options */
 449         lpp_writel(comm, lpp->set_bound);
 450         lpp_writed(comm, lpp->bound);
 451         lpp_writed(comm, lpp->time_limit_secs);
 452         lpp_writel(comm, lpp->emphasis);
 453
 454         for(i = 0; i < lpp->cst_next; ++i) {
 455                 lpp_name_t *name = lpp->csts[i];
 456                 lpp_writel(comm, name->nr);
 457                 lpp_writel(comm, name->value_kind);
 458                 lpp_writel(comm, name->type.cst_type);
 459
 460                 if(with_names)
 461                         lpp_writes(comm, name->name);
 462         }
 463
 464         for(i = 0; i < lpp->var_next; ++i) {
 465                 lpp_name_t *name = lpp->vars[i];
 466                 lpp_writel(comm, name->nr);
 467                 lpp_writel(comm, name->value_kind);
 468                 lpp_writel(comm, name->type.var_type);
 469
 470                 if(with_names)
 471                         lpp_writes(comm, name->name);
 472         }
 473
 474         {
 475                 const matrix_elem_t *elm;
 476                 n = 0;
 477
 478                 matrix_foreach(lpp->m, elm)
 479                         n++;
 480
 481                 assert(n == matrix_get_entries(lpp->m));
 482                 lpp_writel(comm, n);
 483                 matrix_foreach(lpp->m, elm) {
 484                         lpp_writel(comm, elm->row);
 485                         lpp_writel(comm, elm->col);
 486                         lpp_writed(comm, elm->val);
 487                 }
 488         }
 489 }
 490
 491 /**
 492  * Deserialize an lpp from a file descriptor.
 493  * @param comm The file descriptor.
 494  * @return The Problem.
 495  */
 496 lpp_t *lpp_deserialize(lpp_comm_t *comm)
 497 {
 498         int i, n;
 499         int with_names;
 500
 501         lpp_t *lpp = XMALLOCZ(lpp_t);
 502
 503         /* read general settings */
 504         with_names    = lpp_readl(comm);
 505         lpp->cst_next = lpp_readl(comm);
 506         lpp->var_next = lpp_readl(comm);
 507         lpp->opt_type = (lpp_opt_t)lpp_readl(comm);
 508         lpp->name     = lpp_reads(comm);
 509
 510         /* read options */
 511         lpp->set_bound       = lpp_readl(comm);
 512         lpp->bound           = lpp_readd(comm);
 513         lpp->time_limit_secs = lpp_readd(comm);
 514         lpp->emphasis        = (lpp_emphasis_t)lpp_readl(comm);
 515
 516         lpp->cst_size = lpp->cst_next;
 517         lpp->var_size = lpp->var_next;
 518
 519         lpp->cst2nr   = new_set(cmp_name_t, lpp->cst_next);
 520         lpp->var2nr   = new_set(cmp_name_t, lpp->var_next);
 521
 522         lpp->csts     = XMALLOCNZ(lpp_name_t*, lpp->cst_next);
 523         lpp->vars     = XMALLOCNZ(lpp_name_t*, lpp->var_next);
 524         lpp->m        = new_matrix(lpp->cst_next, lpp->var_next);
 525
 526         for(i = 0; i < lpp->cst_next; ++i) {
 527                 lpp_name_t name, *res;
 528
 529                 name.nr            = lpp_readl(comm);
 530                 name.value_kind    = (lpp_value_kind_t)lpp_readl(comm);
 531                 name.type.cst_type = (lpp_cst_t)lpp_readl(comm);
 532
 533                 if(with_names) {
 534                         name.name = lpp_reads(comm);
 535                 } else {
 536                         char* buf = XMALLOCN(char, 32);
 537                         snprintf(buf, 32, "c%d\n", name.nr);
 538                         name.name = buf;
 539                 }
 540
 541                 res = (lpp_name_t*)set_insert(lpp->cst2nr, &name, sizeof(name), HASH_NAME_T(&name));
 542                 lpp->csts[name.nr] = res;
 543         }
 544
 545         for(i = 0; i < lpp->var_next; ++i) {
 546                 lpp_name_t name, *res;
 547
 548                 name.nr            = lpp_readl(comm);
 549                 name.value_kind    = (lpp_value_kind_t)lpp_readl(comm);
 550                 name.type.var_type = (lpp_var_t)lpp_readl(comm);
 551
 552                 if(with_names) {
 553                         name.name = lpp_reads(comm);
 554                 } else {
 555                         char* buf = XMALLOCN(char, 32);
 556                         snprintf(buf, 32, "v%d\n", name.nr);
 557                         name.name = buf;
 558                 }
 559
 560                 res = (lpp_name_t*)set_insert(lpp->var2nr, &name, sizeof(name), HASH_NAME_T(&name));
 561                 lpp->vars[name.nr] = res;
 562         }
 563
 564         n = lpp_readl(comm);
 565         for(i = 0; i < n; ++i) {
 566                 matrix_elem_t elm;
 567                 elm.row = lpp_readl(comm);
 568                 elm.col = lpp_readl(comm);
 569                 elm.val = lpp_readd(comm);
 570                 matrix_set(lpp->m, elm.row, elm.col, elm.val);
 571         }
 572
 573         return lpp;
 574 }
 575
 576 void lpp_serialize_values(lpp_comm_t *comm, const lpp_t *lpp, lpp_value_kind_t value_kind)
 577 {
 578         int i, n;
 579
 580         for(i = 0, n = 0; i < lpp->var_next; ++i)
 581                 n += lpp->vars[i]->value_kind == value_kind;
 582
 583         /* Write the number of values to expect */
 584         lpp_writel(comm, n);
 585
 586         /* send the values */
 587         for(i = 0, n = lpp->var_next; i < n; ++i) {
 588                 const lpp_name_t *name = lpp->vars[i];
 589                 if(name->value_kind == value_kind) {
 590                         lpp_writel(comm, name->nr);
 591                         lpp_writed(comm, name->value);
 592                 }
 593         }
 594 }
 595
 596 void lpp_deserialize_values(lpp_comm_t *comm, lpp_t *lpp, lpp_value_kind_t value_kind)
 597 {
 598         int i, n;
 599
 600         /* Get the number of values to read */
 601         n = lpp_readl(comm);
 602
 603         for(i = 0; i < n; ++i) {
 604                 int nr = lpp_readl(comm);
 605                 lpp_name_t *name = lpp->vars[nr];
 606
 607                 name->value_kind = value_kind;
 608                 name->value = lpp_readd(comm);
 609         }
 610 }
 611
 612 void lpp_serialize_stats(lpp_comm_t *comm, const lpp_t *lpp)
 613 {
 614         lpp_writel(comm, lpp->sol_state);
 615         lpp_writel(comm, lpp->iterations);
 616         lpp_writed(comm, lpp->sol_time);
 617         lpp_writed(comm, lpp->objval);
 618         lpp_writed(comm, lpp->best_bound);
 619 }
 620
 621 void lpp_deserialize_stats(lpp_comm_t *comm, lpp_t *lpp)
 622 {
 623         lpp->sol_state  = (lpp_sol_state_t)lpp_readl(comm);
 624         lpp->iterations = lpp_readl(comm);
 625         lpp->sol_time   = lpp_readd(comm);
 626         lpp->objval     = lpp_readd(comm);
 627         lpp->best_bound = lpp_readd(comm);
 628 }
 629
 630 void lpp_solve(lpp_t *lpp, const char* host, const char* solver)
 631 {
 632         if (host == NULL || strlen(host) == 0) {
 633                 lpp_solver_func_t* f = lpp_find_solver(solver);
 634                 if (f != NULL)
 635                         f(lpp);
 636         } else {
 637                 lpp_solve_net(lpp, host, solver);
 638         }
 639 }
 640