isl_constraint.c

   1 /*
   2  * Copyright 2008-2009 Katholieke Universiteit Leuven
   3  * Copyright 2010      INRIA Saclay
   4  *
   5  * Use of this software is governed by the MIT license
   6  *
   7  * Written by Sven Verdoolaege, K.U.Leuven, Departement
   8  * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
   9  * and INRIA Saclay - Ile-de-France, Parc Club Orsay Universite,
  10  * ZAC des vignes, 4 rue Jacques Monod, 91893 Orsay, France
  11  */
  12
  13 #include <isl_map_private.h>
  14 #include <isl_constraint_private.h>
  15 #include <isl_space_private.h>
  16 #include <isl/seq.h>
  17 #include <isl_aff_private.h>
  18 #include <isl_local_space_private.h>
  19
  20 #undef BASE
  21 #define BASE constraint
  22
  23 #include <isl_list_templ.c>
  24
  25 isl_ctx *isl_constraint_get_ctx(__isl_keep isl_constraint *c)
  26 {
  27         return c ? isl_local_space_get_ctx(c->ls) : NULL;
  28 }
  29
  30 static unsigned n(struct isl_constraint *c, enum isl_dim_type type)
  31 {
  32         return isl_local_space_dim(c->ls, type);
  33 }
  34
  35 static unsigned offset(struct isl_constraint *c, enum isl_dim_type type)
  36 {
  37         return isl_local_space_offset(c->ls, type);
  38 }
  39
  40 static unsigned basic_map_offset(__isl_keep isl_basic_map *bmap,
  41                                                         enum isl_dim_type type)
  42 {
  43         return type == isl_dim_div ? 1 + isl_space_dim(bmap->dim, isl_dim_all)
  44                                    : 1 + isl_space_offset(bmap->dim, type);
  45 }
  46
  47 static unsigned basic_set_offset(struct isl_basic_set *bset,
  48                                                         enum isl_dim_type type)
  49 {
  50         isl_space *dim = bset->dim;
  51         switch (type) {
  52         case isl_dim_param:     return 1;
  53         case isl_dim_in:        return 1 + dim->nparam;
  54         case isl_dim_out:       return 1 + dim->nparam + dim->n_in;
  55         case isl_dim_div:       return 1 + dim->nparam + dim->n_in + dim->n_out;
  56         default:                return 0;
  57         }
  58 }
  59
  60 __isl_give isl_constraint *isl_constraint_alloc_vec(int eq,
  61         __isl_take isl_local_space *ls, __isl_take isl_vec *v)
  62 {
  63         isl_constraint *constraint;
  64
  65         if (!ls || !v)
  66                 goto error;
  67
  68         constraint = isl_alloc_type(isl_vec_get_ctx(v), isl_constraint);
  69         if (!constraint)
  70                 goto error;
  71
  72         constraint->ref = 1;
  73         constraint->eq = eq;
  74         constraint->ls = ls;
  75         constraint->v = v;
  76
  77         return constraint;
  78 error:
  79         isl_local_space_free(ls);
  80         isl_vec_free(v);
  81         return NULL;
  82 }
  83
  84 __isl_give isl_constraint *isl_constraint_alloc(int eq,
  85         __isl_take isl_local_space *ls)
  86 {
  87         isl_ctx *ctx;
  88         isl_vec *v;
  89
  90         if (!ls)
  91                 return NULL;
  92
  93         ctx = isl_local_space_get_ctx(ls);
  94         v = isl_vec_alloc(ctx, 1 + isl_local_space_dim(ls, isl_dim_all));
  95         v = isl_vec_clr(v);
  96         return isl_constraint_alloc_vec(eq, ls, v);
  97 }
  98
  99 struct isl_constraint *isl_basic_map_constraint(struct isl_basic_map *bmap,
 100         isl_int **line)
 101 {
 102         int eq;
 103         isl_ctx *ctx;
 104         isl_vec *v;
 105         isl_local_space *ls = NULL;
 106         isl_constraint *constraint;
 107
 108         if (!bmap || !line)
 109                 goto error;
 110
 111         eq = line >= bmap->eq;
 112
 113         ctx = isl_basic_map_get_ctx(bmap);
 114         ls = isl_basic_map_get_local_space(bmap);
 115         v = isl_vec_alloc(ctx, 1 + isl_local_space_dim(ls, isl_dim_all));
 116         if (!v)
 117                 goto error;
 118         isl_seq_cpy(v->el, line[0], v->size);
 119         constraint = isl_constraint_alloc_vec(eq, ls, v);
 120
 121         isl_basic_map_free(bmap);
 122         return constraint;
 123 error:
 124         isl_local_space_free(ls);
 125         isl_basic_map_free(bmap);
 126         return NULL;
 127 }
 128
 129 struct isl_constraint *isl_basic_set_constraint(struct isl_basic_set *bset,
 130         isl_int **line)
 131 {
 132         return isl_basic_map_constraint((struct isl_basic_map *)bset, line);
 133 }
 134
 135 __isl_give isl_constraint *isl_equality_alloc(__isl_take isl_local_space *ls)
 136 {
 137         return isl_constraint_alloc(1, ls);
 138 }
 139
 140 __isl_give isl_constraint *isl_inequality_alloc(__isl_take isl_local_space *ls)
 141 {
 142         return isl_constraint_alloc(0, ls);
 143 }
 144
 145 struct isl_constraint *isl_constraint_dup(struct isl_constraint *c)
 146 {
 147         if (!c)
 148                 return NULL;
 149
 150         return isl_constraint_alloc_vec(c->eq, isl_local_space_copy(c->ls),
 151                                                 isl_vec_copy(c->v));
 152 }
 153
 154 struct isl_constraint *isl_constraint_cow(struct isl_constraint *c)
 155 {
 156         if (!c)
 157                 return NULL;
 158
 159         if (c->ref == 1)
 160                 return c;
 161         c->ref--;
 162         return isl_constraint_dup(c);
 163 }
 164
 165 struct isl_constraint *isl_constraint_copy(struct isl_constraint *constraint)
 166 {
 167         if (!constraint)
 168                 return NULL;
 169
 170         constraint->ref++;
 171         return constraint;
 172 }
 173
 174 void *isl_constraint_free(struct isl_constraint *c)
 175 {
 176         if (!c)
 177                 return NULL;
 178
 179         if (--c->ref > 0)
 180                 return NULL;
 181
 182         isl_local_space_free(c->ls);
 183         isl_vec_free(c->v);
 184         free(c);
 185
 186         return NULL;
 187 }
 188
 189 /* Return the number of constraints in "bset", i.e., the
 190  * number of times isl_basic_set_foreach_constraint will
 191  * call the callback.
 192  */
 193 int isl_basic_set_n_constraint(__isl_keep isl_basic_set *bset)
 194 {
 195         if (!bset)
 196                 return -1;
 197
 198         return bset->n_eq + bset->n_ineq;
 199 }
 200
 201 int isl_basic_map_foreach_constraint(__isl_keep isl_basic_map *bmap,
 202         int (*fn)(__isl_take isl_constraint *c, void *user), void *user)
 203 {
 204         int i;
 205         struct isl_constraint *c;
 206
 207         if (!bmap)
 208                 return -1;
 209
 210         isl_assert(bmap->ctx, ISL_F_ISSET(bmap, ISL_BASIC_MAP_FINAL),
 211                         return -1);
 212
 213         for (i = 0; i < bmap->n_eq; ++i) {
 214                 c = isl_basic_map_constraint(isl_basic_map_copy(bmap),
 215                                                 &bmap->eq[i]);
 216                 if (!c)
 217                         return -1;
 218                 if (fn(c, user) < 0)
 219                         return -1;
 220         }
 221
 222         for (i = 0; i < bmap->n_ineq; ++i) {
 223                 c = isl_basic_map_constraint(isl_basic_map_copy(bmap),
 224                                                 &bmap->ineq[i]);
 225                 if (!c)
 226                         return -1;
 227                 if (fn(c, user) < 0)
 228                         return -1;
 229         }
 230
 231         return 0;
 232 }
 233
 234 int isl_basic_set_foreach_constraint(__isl_keep isl_basic_set *bset,
 235         int (*fn)(__isl_take isl_constraint *c, void *user), void *user)
 236 {
 237         return isl_basic_map_foreach_constraint((isl_basic_map *)bset, fn, user);
 238 }
 239
 240 int isl_constraint_is_equal(struct isl_constraint *constraint1,
 241         struct isl_constraint *constraint2)
 242 {
 243         int equal;
 244
 245         if (!constraint1 || !constraint2)
 246                 return 0;
 247         if (constraint1->eq != constraint2->eq)
 248                 return 0;
 249         equal = isl_local_space_is_equal(constraint1->ls, constraint2->ls);
 250         if (equal < 0 || !equal)
 251                 return equal;
 252         return isl_vec_is_equal(constraint1->v, constraint2->v);
 253 }
 254
 255 struct isl_basic_map *isl_basic_map_add_constraint(
 256         struct isl_basic_map *bmap, struct isl_constraint *constraint)
 257 {
 258         isl_ctx *ctx;
 259         isl_space *dim;
 260         int equal_space;
 261
 262         if (!bmap || !constraint)
 263                 goto error;
 264
 265         ctx = isl_constraint_get_ctx(constraint);
 266         dim = isl_constraint_get_space(constraint);
 267         equal_space = isl_space_is_equal(bmap->dim, dim);
 268         isl_space_free(dim);
 269         isl_assert(ctx, equal_space, goto error);
 270
 271         bmap = isl_basic_map_intersect(bmap,
 272                                 isl_basic_map_from_constraint(constraint));
 273         return bmap;
 274 error:
 275         isl_basic_map_free(bmap);
 276         isl_constraint_free(constraint);
 277         return NULL;
 278 }
 279
 280 struct isl_basic_set *isl_basic_set_add_constraint(
 281         struct isl_basic_set *bset, struct isl_constraint *constraint)
 282 {
 283         return (struct isl_basic_set *)
 284                 isl_basic_map_add_constraint((struct isl_basic_map *)bset,
 285                                                 constraint);
 286 }
 287
 288 __isl_give isl_map *isl_map_add_constraint(__isl_take isl_map *map,
 289         __isl_take isl_constraint *constraint)
 290 {
 291         isl_basic_map *bmap;
 292
 293         bmap = isl_basic_map_from_constraint(constraint);
 294         map = isl_map_intersect(map, isl_map_from_basic_map(bmap));
 295
 296         return map;
 297 }
 298
 299 __isl_give isl_set *isl_set_add_constraint(__isl_take isl_set *set,
 300         __isl_take isl_constraint *constraint)
 301 {
 302         return isl_map_add_constraint(set, constraint);
 303 }
 304
 305 __isl_give isl_space *isl_constraint_get_space(
 306         __isl_keep isl_constraint *constraint)
 307 {
 308         return constraint ? isl_local_space_get_space(constraint->ls) : NULL;
 309 }
 310
 311 __isl_give isl_local_space *isl_constraint_get_local_space(
 312         __isl_keep isl_constraint *constraint)
 313 {
 314         return constraint ? isl_local_space_copy(constraint->ls) : NULL;
 315 }
 316
 317 int isl_constraint_dim(struct isl_constraint *constraint,
 318         enum isl_dim_type type)
 319 {
 320         if (!constraint)
 321                 return -1;
 322         return n(constraint, type);
 323 }
 324
 325 int isl_constraint_involves_dims(__isl_keep isl_constraint *constraint,
 326         enum isl_dim_type type, unsigned first, unsigned n)
 327 {
 328         int i;
 329         isl_ctx *ctx;
 330         int *active = NULL;
 331         int involves = 0;
 332
 333         if (!constraint)
 334                 return -1;
 335         if (n == 0)
 336                 return 0;
 337
 338         ctx = isl_constraint_get_ctx(constraint);
 339         if (first + n > isl_constraint_dim(constraint, type))
 340                 isl_die(ctx, isl_error_invalid,
 341                         "range out of bounds", return -1);
 342
 343         active = isl_local_space_get_active(constraint->ls,
 344                                             constraint->v->el + 1);
 345         if (!active)
 346                 goto error;
 347
 348         first += isl_local_space_offset(constraint->ls, type) - 1;
 349         for (i = 0; i < n; ++i)
 350                 if (active[first + i]) {
 351                         involves = 1;
 352                         break;
 353                 }
 354
 355         free(active);
 356
 357         return involves;
 358 error:
 359         free(active);
 360         return -1;
 361 }
 362
 363 /* Does the given constraint represent a lower bound on the given
 364  * dimension?
 365  */
 366 int isl_constraint_is_lower_bound(__isl_keep isl_constraint *constraint,
 367         enum isl_dim_type type, unsigned pos)
 368 {
 369         if (!constraint)
 370                 return -1;
 371
 372         if (pos >= isl_local_space_dim(constraint->ls, type))
 373                 isl_die(isl_constraint_get_ctx(constraint), isl_error_invalid,
 374                         "position out of bounds", return -1);
 375
 376         pos += isl_local_space_offset(constraint->ls, type);
 377         return isl_int_is_pos(constraint->v->el[pos]);
 378 }
 379
 380 /* Does the given constraint represent an upper bound on the given
 381  * dimension?
 382  */
 383 int isl_constraint_is_upper_bound(__isl_keep isl_constraint *constraint,
 384         enum isl_dim_type type, unsigned pos)
 385 {
 386         if (!constraint)
 387                 return -1;
 388
 389         if (pos >= isl_local_space_dim(constraint->ls, type))
 390                 isl_die(isl_constraint_get_ctx(constraint), isl_error_invalid,
 391                         "position out of bounds", return -1);
 392
 393         pos += isl_local_space_offset(constraint->ls, type);
 394         return isl_int_is_neg(constraint->v->el[pos]);
 395 }
 396
 397 const char *isl_constraint_get_dim_name(__isl_keep isl_constraint *constraint,
 398         enum isl_dim_type type, unsigned pos)
 399 {
 400         return constraint ?
 401             isl_local_space_get_dim_name(constraint->ls, type, pos) : NULL;
 402 }
 403
 404 void isl_constraint_get_constant(struct isl_constraint *constraint, isl_int *v)
 405 {
 406         if (!constraint)
 407                 return;
 408         isl_int_set(*v, constraint->v->el[0]);
 409 }
 410
 411 void isl_constraint_get_coefficient(struct isl_constraint *constraint,
 412         enum isl_dim_type type, int pos, isl_int *v)
 413 {
 414         if (!constraint)
 415                 return;
 416
 417         if (pos >= isl_local_space_dim(constraint->ls, type))
 418                 isl_die(constraint->v->ctx, isl_error_invalid,
 419                         "position out of bounds", return);
 420
 421         pos += isl_local_space_offset(constraint->ls, type);
 422         isl_int_set(*v, constraint->v->el[pos]);
 423 }
 424
 425 __isl_give isl_aff *isl_constraint_get_div(__isl_keep isl_constraint *constraint,
 426         int pos)
 427 {
 428         if (!constraint)
 429                 return NULL;
 430
 431         return isl_local_space_get_div(constraint->ls, pos);
 432 }
 433
 434 __isl_give isl_constraint *isl_constraint_set_constant(
 435         __isl_take isl_constraint *constraint, isl_int v)
 436 {
 437         constraint = isl_constraint_cow(constraint);
 438         if (!constraint)
 439                 return NULL;
 440
 441         constraint->v = isl_vec_cow(constraint->v);
 442         if (!constraint->v)
 443                 return isl_constraint_free(constraint);
 444
 445         isl_int_set(constraint->v->el[0], v);
 446         return constraint;
 447 }
 448
 449 /* Replace the constant term of "constraint" by "v".
 450  */
 451 __isl_give isl_constraint *isl_constraint_set_constant_val(
 452         __isl_take isl_constraint *constraint, __isl_take isl_val *v)
 453 {
 454         constraint = isl_constraint_cow(constraint);
 455         if (!constraint || !v)
 456                 goto error;
 457         if (!isl_val_is_int(v))
 458                 isl_die(isl_constraint_get_ctx(constraint), isl_error_invalid,
 459                         "expecting integer value", goto error);
 460         constraint->v = isl_vec_set_element_val(constraint->v, 0, v);
 461         if (!constraint->v)
 462                 constraint = isl_constraint_free(constraint);
 463         return constraint;
 464 error:
 465         isl_val_free(v);
 466         return isl_constraint_free(constraint);
 467 }
 468
 469 __isl_give isl_constraint *isl_constraint_set_constant_si(
 470         __isl_take isl_constraint *constraint, int v)
 471 {
 472         constraint = isl_constraint_cow(constraint);
 473         if (!constraint)
 474                 return NULL;
 475
 476         constraint->v = isl_vec_cow(constraint->v);
 477         if (!constraint->v)
 478                 return isl_constraint_free(constraint);
 479
 480         isl_int_set_si(constraint->v->el[0], v);
 481         return constraint;
 482 }
 483
 484 __isl_give isl_constraint *isl_constraint_set_coefficient(
 485         __isl_take isl_constraint *constraint,
 486         enum isl_dim_type type, int pos, isl_int v)
 487 {
 488         constraint = isl_constraint_cow(constraint);
 489         if (!constraint)
 490                 return NULL;
 491
 492         if (pos >= isl_local_space_dim(constraint->ls, type))
 493                 isl_die(constraint->v->ctx, isl_error_invalid,
 494                         "position out of bounds",
 495                         return isl_constraint_free(constraint));
 496
 497         constraint = isl_constraint_cow(constraint);
 498         if (!constraint)
 499                 return NULL;
 500
 501         constraint->v = isl_vec_cow(constraint->v);
 502         if (!constraint->v)
 503                 return isl_constraint_free(constraint);
 504
 505         pos += isl_local_space_offset(constraint->ls, type);
 506         isl_int_set(constraint->v->el[pos], v);
 507
 508         return constraint;
 509 }
 510
 511 /* Replace the coefficient of the variable of type "type" at position "pos"
 512  * of "constraint" by "v".
 513  */
 514 __isl_give isl_constraint *isl_constraint_set_coefficient_val(
 515         __isl_take isl_constraint *constraint,
 516         enum isl_dim_type type, int pos, isl_val *v)
 517 {
 518         constraint = isl_constraint_cow(constraint);
 519         if (!constraint || !v)
 520                 goto error;
 521         if (!isl_val_is_int(v))
 522                 isl_die(isl_constraint_get_ctx(constraint), isl_error_invalid,
 523                         "expecting integer value", goto error);
 524
 525         if (pos >= isl_local_space_dim(constraint->ls, type))
 526                 isl_die(isl_constraint_get_ctx(constraint), isl_error_invalid,
 527                         "position out of bounds", goto error);
 528
 529         pos += isl_local_space_offset(constraint->ls, type);
 530         constraint->v = isl_vec_set_element_val(constraint->v, pos, v);
 531         if (!constraint->v)
 532                 constraint = isl_constraint_free(constraint);
 533         return constraint;
 534 error:
 535         isl_val_free(v);
 536         return isl_constraint_free(constraint);
 537 }
 538
 539 __isl_give isl_constraint *isl_constraint_set_coefficient_si(
 540         __isl_take isl_constraint *constraint,
 541         enum isl_dim_type type, int pos, int v)
 542 {
 543         constraint = isl_constraint_cow(constraint);
 544         if (!constraint)
 545                 return NULL;
 546
 547         if (pos >= isl_local_space_dim(constraint->ls, type))
 548                 isl_die(constraint->v->ctx, isl_error_invalid,
 549                         "position out of bounds",
 550                         return isl_constraint_free(constraint));
 551
 552         constraint = isl_constraint_cow(constraint);
 553         if (!constraint)
 554                 return NULL;
 555
 556         constraint->v = isl_vec_cow(constraint->v);
 557         if (!constraint->v)
 558                 return isl_constraint_free(constraint);
 559
 560         pos += isl_local_space_offset(constraint->ls, type);
 561         isl_int_set_si(constraint->v->el[pos], v);
 562
 563         return constraint;
 564 }
 565
 566 /* Drop any constraint from "bset" that is identical to "constraint".
 567  * In particular, this means that the local spaces of "bset" and
 568  * "constraint" need to be the same.
 569  *
 570  * Since the given constraint may actually be a pointer into the bset,
 571  * we have to be careful not to reorder the constraints as the user
 572  * may be holding on to other constraints from the same bset.
 573  * This should be cleaned up when the internal representation of
 574  * isl_constraint is changed to use isl_aff.
 575  */
 576 __isl_give isl_basic_set *isl_basic_set_drop_constraint(
 577         __isl_take isl_basic_set *bset, __isl_take isl_constraint *constraint)
 578 {
 579         int i;
 580         unsigned n;
 581         isl_int **row;
 582         unsigned total;
 583         isl_local_space *ls1;
 584         int equal;
 585
 586         if (!bset || !constraint)
 587                 goto error;
 588
 589         ls1 = isl_basic_set_get_local_space(bset);
 590         equal = isl_local_space_is_equal(ls1, constraint->ls);
 591         isl_local_space_free(ls1);
 592         if (equal < 0)
 593                 goto error;
 594         if (!equal) {
 595                 isl_constraint_free(constraint);
 596                 return bset;
 597         }
 598
 599         if (isl_constraint_is_equality(constraint)) {
 600                 n = bset->n_eq;
 601                 row = bset->eq;
 602         } else {
 603                 n = bset->n_ineq;
 604                 row = bset->ineq;
 605         }
 606
 607         total = isl_constraint_dim(constraint, isl_dim_all);
 608         for (i = 0; i < n; ++i)
 609                 if (isl_seq_eq(row[i], constraint->v->el, 1 + total))
 610                         isl_seq_clr(row[i], 1 + total);
 611
 612         isl_constraint_free(constraint);
 613         return bset;
 614 error:
 615         isl_constraint_free(constraint);
 616         isl_basic_set_free(bset);
 617         return NULL;
 618 }
 619
 620 struct isl_constraint *isl_constraint_negate(struct isl_constraint *constraint)
 621 {
 622         isl_ctx *ctx;
 623
 624         constraint = isl_constraint_cow(constraint);
 625         if (!constraint)
 626                 return NULL;
 627
 628         ctx = isl_constraint_get_ctx(constraint);
 629         if (isl_constraint_is_equality(constraint))
 630                 isl_die(ctx, isl_error_invalid, "cannot negate equality",
 631                         return isl_constraint_free(constraint));
 632         constraint->v = isl_vec_neg(constraint->v);
 633         constraint->v = isl_vec_cow(constraint->v);
 634         if (!constraint->v)
 635                 return isl_constraint_free(constraint);
 636         isl_int_sub_ui(constraint->v->el[0], constraint->v->el[0], 1);
 637         return constraint;
 638 }
 639
 640 int isl_constraint_is_equality(struct isl_constraint *constraint)
 641 {
 642         if (!constraint)
 643                 return -1;
 644         return constraint->eq;
 645 }
 646
 647 int isl_constraint_is_div_constraint(__isl_keep isl_constraint *constraint)
 648 {
 649         int i;
 650         int n_div;
 651
 652         if (!constraint)
 653                 return -1;
 654         if (isl_constraint_is_equality(constraint))
 655                 return 0;
 656         n_div = isl_constraint_dim(constraint, isl_dim_div);
 657         for (i = 0; i < n_div; ++i) {
 658                 if (isl_local_space_is_div_constraint(constraint->ls,
 659                                                         constraint->v->el, i))
 660                         return 1;
 661         }
 662
 663         return 0;
 664 }
 665
 666 /* We manually set ISL_BASIC_SET_FINAL instead of calling
 667  * isl_basic_map_finalize because we want to keep the position
 668  * of the divs and we therefore do not want to throw away redundant divs.
 669  * This is arguably a bit fragile.
 670  */
 671 __isl_give isl_basic_map *isl_basic_map_from_constraint(
 672         __isl_take isl_constraint *constraint)
 673 {
 674         int k;
 675         isl_local_space *ls;
 676         struct isl_basic_map *bmap;
 677         isl_int *c;
 678         unsigned total;
 679
 680         if (!constraint)
 681                 return NULL;
 682
 683         ls = isl_local_space_copy(constraint->ls);
 684         bmap = isl_basic_map_from_local_space(ls);
 685         bmap = isl_basic_map_extend_constraints(bmap, 1, 1);
 686         if (isl_constraint_is_equality(constraint)) {
 687                 k = isl_basic_map_alloc_equality(bmap);
 688                 if (k < 0)
 689                         goto error;
 690                 c = bmap->eq[k];
 691         }
 692         else {
 693                 k = isl_basic_map_alloc_inequality(bmap);
 694                 if (k < 0)
 695                         goto error;
 696                 c = bmap->ineq[k];
 697         }
 698         total = isl_basic_map_total_dim(bmap);
 699         isl_seq_cpy(c, constraint->v->el, 1 + total);
 700         isl_constraint_free(constraint);
 701         if (bmap)
 702                 ISL_F_SET(bmap, ISL_BASIC_SET_FINAL);
 703         return bmap;
 704 error:
 705         isl_constraint_free(constraint);
 706         isl_basic_map_free(bmap);
 707         return NULL;
 708 }
 709
 710 struct isl_basic_set *isl_basic_set_from_constraint(
 711         struct isl_constraint *constraint)
 712 {
 713         if (!constraint)
 714                 return NULL;
 715
 716         if (isl_constraint_dim(constraint, isl_dim_in) != 0)
 717                 isl_die(isl_constraint_get_ctx(constraint), isl_error_invalid,
 718                         "not a set constraint",
 719                         return isl_constraint_free(constraint));
 720         return (isl_basic_set *)isl_basic_map_from_constraint(constraint);
 721 }
 722
 723 int isl_basic_map_has_defining_equality(
 724         __isl_keep isl_basic_map *bmap, enum isl_dim_type type, int pos,
 725         __isl_give isl_constraint **c)
 726 {
 727         int i;
 728         unsigned offset;
 729         unsigned total;
 730
 731         if (!bmap)
 732                 return -1;
 733         offset = basic_map_offset(bmap, type);
 734         total = isl_basic_map_total_dim(bmap);
 735         isl_assert(bmap->ctx, pos < isl_basic_map_dim(bmap, type), return -1);
 736         for (i = 0; i < bmap->n_eq; ++i)
 737                 if (!isl_int_is_zero(bmap->eq[i][offset + pos]) &&
 738                     isl_seq_first_non_zero(bmap->eq[i]+offset+pos+1,
 739                                            1+total-offset-pos-1) == -1) {
 740                         *c = isl_basic_map_constraint(isl_basic_map_copy(bmap),
 741                                                                 &bmap->eq[i]);
 742                         return 1;
 743                 }
 744         return 0;
 745 }
 746
 747 int isl_basic_set_has_defining_equality(
 748         __isl_keep isl_basic_set *bset, enum isl_dim_type type, int pos,
 749         __isl_give isl_constraint **c)
 750 {
 751         return isl_basic_map_has_defining_equality((isl_basic_map *)bset,
 752                                                     type, pos, c);
 753 }
 754
 755 int isl_basic_set_has_defining_inequalities(
 756         struct isl_basic_set *bset, enum isl_dim_type type, int pos,
 757         struct isl_constraint **lower,
 758         struct isl_constraint **upper)
 759 {
 760         int i, j;
 761         unsigned offset;
 762         unsigned total;
 763         isl_int m;
 764         isl_int **lower_line, **upper_line;
 765
 766         if (!bset)
 767                 return -1;
 768         offset = basic_set_offset(bset, type);
 769         total = isl_basic_set_total_dim(bset);
 770         isl_assert(bset->ctx, pos < isl_basic_set_dim(bset, type), return -1);
 771         isl_int_init(m);
 772         for (i = 0; i < bset->n_ineq; ++i) {
 773                 if (isl_int_is_zero(bset->ineq[i][offset + pos]))
 774                         continue;
 775                 if (isl_int_is_one(bset->ineq[i][offset + pos]))
 776                         continue;
 777                 if (isl_int_is_negone(bset->ineq[i][offset + pos]))
 778                         continue;
 779                 if (isl_seq_first_non_zero(bset->ineq[i]+offset+pos+1,
 780                                                 1+total-offset-pos-1) != -1)
 781                         continue;
 782                 for (j = i + 1; j < bset->n_ineq; ++j) {
 783                         if (!isl_seq_is_neg(bset->ineq[i]+1, bset->ineq[j]+1,
 784                                             total))
 785                                 continue;
 786                         isl_int_add(m, bset->ineq[i][0], bset->ineq[j][0]);
 787                         if (isl_int_abs_ge(m, bset->ineq[i][offset+pos]))
 788                                 continue;
 789
 790                         if (isl_int_is_pos(bset->ineq[i][offset+pos])) {
 791                                 lower_line = &bset->ineq[i];
 792                                 upper_line = &bset->ineq[j];
 793                         } else {
 794                                 lower_line = &bset->ineq[j];
 795                                 upper_line = &bset->ineq[i];
 796                         }
 797                         *lower = isl_basic_set_constraint(
 798                                         isl_basic_set_copy(bset), lower_line);
 799                         *upper = isl_basic_set_constraint(
 800                                         isl_basic_set_copy(bset), upper_line);
 801                         isl_int_clear(m);
 802                         return 1;
 803                 }
 804         }
 805         *lower = NULL;
 806         *upper = NULL;
 807         isl_int_clear(m);
 808         return 0;
 809 }
 810
 811 /* Given two constraints "a" and "b" on the variable at position "abs_pos"
 812  * (in "a" and "b"), add a constraint to "bset" that ensures that the
 813  * bound implied by "a" is (strictly) larger than the bound implied by "b".
 814  *
 815  * If both constraints imply lower bounds, then this means that "a" is
 816  * active in the result.
 817  * If both constraints imply upper bounds, then this means that "b" is
 818  * active in the result.
 819  */
 820 static __isl_give isl_basic_set *add_larger_bound_constraint(
 821         __isl_take isl_basic_set *bset, isl_int *a, isl_int *b,
 822         unsigned abs_pos, int strict)
 823 {
 824         int k;
 825         isl_int t;
 826         unsigned total;
 827
 828         k = isl_basic_set_alloc_inequality(bset);
 829         if (k < 0)
 830                 goto error;
 831
 832         total = isl_basic_set_dim(bset, isl_dim_all);
 833
 834         isl_int_init(t);
 835         isl_int_neg(t, b[1 + abs_pos]);
 836
 837         isl_seq_combine(bset->ineq[k], t, a, a[1 + abs_pos], b, 1 + abs_pos);
 838         isl_seq_combine(bset->ineq[k] + 1 + abs_pos,
 839                 t, a + 1 + abs_pos + 1, a[1 + abs_pos], b + 1 + abs_pos + 1,
 840                 total - abs_pos);
 841
 842         if (strict)
 843                 isl_int_sub_ui(bset->ineq[k][0], bset->ineq[k][0], 1);
 844
 845         isl_int_clear(t);
 846
 847         return bset;
 848 error:
 849         isl_basic_set_free(bset);
 850         return NULL;
 851 }
 852
 853 /* Add constraints to "context" that ensure that "u" is the smallest
 854  * (and therefore active) upper bound on "abs_pos" in "bset" and return
 855  * the resulting basic set.
 856  */
 857 static __isl_give isl_basic_set *set_smallest_upper_bound(
 858         __isl_keep isl_basic_set *context,
 859         __isl_keep isl_basic_set *bset, unsigned abs_pos, int n_upper, int u)
 860 {
 861         int j;
 862
 863         context = isl_basic_set_copy(context);
 864         context = isl_basic_set_cow(context);
 865
 866         context = isl_basic_set_extend_constraints(context, 0, n_upper - 1);
 867
 868         for (j = 0; j < bset->n_ineq; ++j) {
 869                 if (j == u)
 870                         continue;
 871                 if (!isl_int_is_neg(bset->ineq[j][1 + abs_pos]))
 872                         continue;
 873                 context = add_larger_bound_constraint(context,
 874                         bset->ineq[j], bset->ineq[u], abs_pos, j > u);
 875         }
 876
 877         context = isl_basic_set_simplify(context);
 878         context = isl_basic_set_finalize(context);
 879
 880         return context;
 881 }
 882
 883 /* Add constraints to "context" that ensure that "u" is the largest
 884  * (and therefore active) upper bound on "abs_pos" in "bset" and return
 885  * the resulting basic set.
 886  */
 887 static __isl_give isl_basic_set *set_largest_lower_bound(
 888         __isl_keep isl_basic_set *context,
 889         __isl_keep isl_basic_set *bset, unsigned abs_pos, int n_lower, int l)
 890 {
 891         int j;
 892
 893         context = isl_basic_set_copy(context);
 894         context = isl_basic_set_cow(context);
 895
 896         context = isl_basic_set_extend_constraints(context, 0, n_lower - 1);
 897
 898         for (j = 0; j < bset->n_ineq; ++j) {
 899                 if (j == l)
 900                         continue;
 901                 if (!isl_int_is_pos(bset->ineq[j][1 + abs_pos]))
 902                         continue;
 903                 context = add_larger_bound_constraint(context,
 904                         bset->ineq[l], bset->ineq[j], abs_pos, j > l);
 905         }
 906
 907         context = isl_basic_set_simplify(context);
 908         context = isl_basic_set_finalize(context);
 909
 910         return context;
 911 }
 912
 913 static int foreach_upper_bound(__isl_keep isl_basic_set *bset,
 914         enum isl_dim_type type, unsigned abs_pos,
 915         __isl_take isl_basic_set *context, int n_upper,
 916         int (*fn)(__isl_take isl_constraint *lower,
 917                   __isl_take isl_constraint *upper,
 918                   __isl_take isl_basic_set *bset, void *user), void *user)
 919 {
 920         isl_basic_set *context_i;
 921         isl_constraint *upper = NULL;
 922         int i;
 923
 924         for (i = 0; i < bset->n_ineq; ++i) {
 925                 if (isl_int_is_zero(bset->ineq[i][1 + abs_pos]))
 926                         continue;
 927
 928                 context_i = set_smallest_upper_bound(context, bset,
 929                                                         abs_pos, n_upper, i);
 930                 if (isl_basic_set_is_empty(context_i)) {
 931                         isl_basic_set_free(context_i);
 932                         continue;
 933                 }
 934                 upper = isl_basic_set_constraint(isl_basic_set_copy(bset),
 935                                                 &bset->ineq[i]);
 936                 if (!upper || !context_i)
 937                         goto error;
 938                 if (fn(NULL, upper, context_i, user) < 0)
 939                         break;
 940         }
 941
 942         isl_basic_set_free(context);
 943
 944         if (i < bset->n_ineq)
 945                 return -1;
 946
 947         return 0;
 948 error:
 949         isl_constraint_free(upper);
 950         isl_basic_set_free(context_i);
 951         isl_basic_set_free(context);
 952         return -1;
 953 }
 954
 955 static int foreach_lower_bound(__isl_keep isl_basic_set *bset,
 956         enum isl_dim_type type, unsigned abs_pos,
 957         __isl_take isl_basic_set *context, int n_lower,
 958         int (*fn)(__isl_take isl_constraint *lower,
 959                   __isl_take isl_constraint *upper,
 960                   __isl_take isl_basic_set *bset, void *user), void *user)
 961 {
 962         isl_basic_set *context_i;
 963         isl_constraint *lower = NULL;
 964         int i;
 965
 966         for (i = 0; i < bset->n_ineq; ++i) {
 967                 if (isl_int_is_zero(bset->ineq[i][1 + abs_pos]))
 968                         continue;
 969
 970                 context_i = set_largest_lower_bound(context, bset,
 971                                                         abs_pos, n_lower, i);
 972                 if (isl_basic_set_is_empty(context_i)) {
 973                         isl_basic_set_free(context_i);
 974                         continue;
 975                 }
 976                 lower = isl_basic_set_constraint(isl_basic_set_copy(bset),
 977                                                 &bset->ineq[i]);
 978                 if (!lower || !context_i)
 979                         goto error;
 980                 if (fn(lower, NULL, context_i, user) < 0)
 981                         break;
 982         }
 983
 984         isl_basic_set_free(context);
 985
 986         if (i < bset->n_ineq)
 987                 return -1;
 988
 989         return 0;
 990 error:
 991         isl_constraint_free(lower);
 992         isl_basic_set_free(context_i);
 993         isl_basic_set_free(context);
 994         return -1;
 995 }
 996
 997 static int foreach_bound_pair(__isl_keep isl_basic_set *bset,
 998         enum isl_dim_type type, unsigned abs_pos,
 999         __isl_take isl_basic_set *context, int n_lower, int n_upper,
1000         int (*fn)(__isl_take isl_constraint *lower,
1001                   __isl_take isl_constraint *upper,
1002                   __isl_take isl_basic_set *bset, void *user), void *user)
1003 {
1004         isl_basic_set *context_i, *context_j;
1005         isl_constraint *lower = NULL;
1006         isl_constraint *upper = NULL;
1007         int i, j;
1008
1009         for (i = 0; i < bset->n_ineq; ++i) {
1010                 if (!isl_int_is_pos(bset->ineq[i][1 + abs_pos]))
1011                         continue;
1012
1013                 context_i = set_largest_lower_bound(context, bset,
1014                                                         abs_pos, n_lower, i);
1015                 if (isl_basic_set_is_empty(context_i)) {
1016                         isl_basic_set_free(context_i);
1017                         continue;
1018                 }
1019
1020                 for (j = 0; j < bset->n_ineq; ++j) {
1021                         if (!isl_int_is_neg(bset->ineq[j][1 + abs_pos]))
1022                                 continue;
1023
1024                         context_j = set_smallest_upper_bound(context_i, bset,
1025                                                             abs_pos, n_upper, j);
1026                         context_j = isl_basic_set_extend_constraints(context_j,
1027                                                                         0, 1);
1028                         context_j = add_larger_bound_constraint(context_j,
1029                                 bset->ineq[i], bset->ineq[j], abs_pos, 0);
1030                         context_j = isl_basic_set_simplify(context_j);
1031                         context_j = isl_basic_set_finalize(context_j);
1032                         if (isl_basic_set_is_empty(context_j)) {
1033                                 isl_basic_set_free(context_j);
1034                                 continue;
1035                         }
1036                         lower = isl_basic_set_constraint(isl_basic_set_copy(bset),
1037                                                         &bset->ineq[i]);
1038                         upper = isl_basic_set_constraint(isl_basic_set_copy(bset),
1039                                                         &bset->ineq[j]);
1040                         if (!lower || !upper || !context_j)
1041                                 goto error;
1042                         if (fn(lower, upper, context_j, user) < 0)
1043                                 break;
1044                 }
1045
1046                 isl_basic_set_free(context_i);
1047
1048                 if (j < bset->n_ineq)
1049                         break;
1050         }
1051
1052         isl_basic_set_free(context);
1053
1054         if (i < bset->n_ineq)
1055                 return -1;
1056
1057         return 0;
1058 error:
1059         isl_constraint_free(lower);
1060         isl_constraint_free(upper);
1061         isl_basic_set_free(context_i);
1062         isl_basic_set_free(context_j);
1063         isl_basic_set_free(context);
1064         return -1;
1065 }
1066
1067 /* For each pair of lower and upper bounds on the variable "pos"
1068  * of type "type", call "fn" with these lower and upper bounds and the
1069  * set of constraints on the remaining variables where these bounds
1070  * are active, i.e., (stricly) larger/smaller than the other lower/upper bounds.
1071  *
1072  * If the designated variable is equal to an affine combination of the
1073  * other variables then fn is called with both lower and upper
1074  * set to the corresponding equality.
1075  *
1076  * If there is no lower (or upper) bound, then NULL is passed
1077  * as the corresponding bound.
1078  *
1079  * We first check if the variable is involved in any equality.
1080  * If not, we count the number of lower and upper bounds and
1081  * act accordingly.
1082  */
1083 int isl_basic_set_foreach_bound_pair(__isl_keep isl_basic_set *bset,
1084         enum isl_dim_type type, unsigned pos,
1085         int (*fn)(__isl_take isl_constraint *lower,
1086                   __isl_take isl_constraint *upper,
1087                   __isl_take isl_basic_set *bset, void *user), void *user)
1088 {
1089         int i;
1090         isl_constraint *lower = NULL;
1091         isl_constraint *upper = NULL;
1092         isl_basic_set *context = NULL;
1093         unsigned abs_pos;
1094         int n_lower, n_upper;
1095
1096         if (!bset)
1097                 return -1;
1098         isl_assert(bset->ctx, pos < isl_basic_set_dim(bset, type), return -1);
1099         isl_assert(bset->ctx, type == isl_dim_param || type == isl_dim_set,
1100                 return -1);
1101
1102         abs_pos = pos;
1103         if (type == isl_dim_set)
1104                 abs_pos += isl_basic_set_dim(bset, isl_dim_param);
1105
1106         for (i = 0; i < bset->n_eq; ++i) {
1107                 if (isl_int_is_zero(bset->eq[i][1 + abs_pos]))
1108                         continue;
1109
1110                 lower = isl_basic_set_constraint(isl_basic_set_copy(bset),
1111                                                 &bset->eq[i]);
1112                 upper = isl_constraint_copy(lower);
1113                 context = isl_basic_set_remove_dims(isl_basic_set_copy(bset),
1114                                         type, pos, 1);
1115                 if (!lower || !upper || !context)
1116                         goto error;
1117                 return fn(lower, upper, context, user);
1118         }
1119
1120         n_lower = 0;
1121         n_upper = 0;
1122         for (i = 0; i < bset->n_ineq; ++i) {
1123                 if (isl_int_is_pos(bset->ineq[i][1 + abs_pos]))
1124                         n_lower++;
1125                 else if (isl_int_is_neg(bset->ineq[i][1 + abs_pos]))
1126                         n_upper++;
1127         }
1128
1129         context = isl_basic_set_copy(bset);
1130         context = isl_basic_set_cow(context);
1131         if (!context)
1132                 goto error;
1133         for (i = context->n_ineq - 1; i >= 0; --i)
1134                 if (!isl_int_is_zero(context->ineq[i][1 + abs_pos]))
1135                         isl_basic_set_drop_inequality(context, i);
1136
1137         context = isl_basic_set_drop(context, type, pos, 1);
1138         if (!n_lower && !n_upper)
1139                 return fn(NULL, NULL, context, user);
1140         if (!n_lower)
1141                 return foreach_upper_bound(bset, type, abs_pos, context, n_upper,
1142                                                 fn, user);
1143         if (!n_upper)
1144                 return foreach_lower_bound(bset, type, abs_pos, context, n_lower,
1145                                                 fn, user);
1146         return foreach_bound_pair(bset, type, abs_pos, context, n_lower, n_upper,
1147                                         fn, user);
1148 error:
1149         isl_constraint_free(lower);
1150         isl_constraint_free(upper);
1151         isl_basic_set_free(context);
1152         return -1;
1153 }
1154
1155 __isl_give isl_aff *isl_constraint_get_bound(
1156         __isl_keep isl_constraint *constraint, enum isl_dim_type type, int pos)
1157 {
1158         isl_aff *aff;
1159         isl_ctx *ctx;
1160
1161         if (!constraint)
1162                 return NULL;
1163         ctx = isl_constraint_get_ctx(constraint);
1164         if (pos >= isl_constraint_dim(constraint, type))
1165                 isl_die(ctx, isl_error_invalid,
1166                         "index out of bounds", return NULL);
1167         if (isl_constraint_dim(constraint, isl_dim_in) != 0)
1168                 isl_die(ctx, isl_error_invalid,
1169                         "not a set constraint", return NULL);
1170
1171         pos += offset(constraint, type);
1172         if (isl_int_is_zero(constraint->v->el[pos]))
1173                 isl_die(ctx, isl_error_invalid,
1174                         "constraint does not define a bound on given dimension",
1175                         return NULL);
1176
1177         aff = isl_aff_alloc(isl_local_space_copy(constraint->ls));
1178         if (!aff)
1179                 return NULL;
1180
1181         if (isl_int_is_neg(constraint->v->el[pos]))
1182                 isl_seq_cpy(aff->v->el + 1, constraint->v->el, aff->v->size - 1);
1183         else
1184                 isl_seq_neg(aff->v->el + 1, constraint->v->el, aff->v->size - 1);
1185         isl_int_set_si(aff->v->el[1 + pos], 0);
1186         isl_int_abs(aff->v->el[0], constraint->v->el[pos]);
1187
1188         return aff;
1189 }
1190
1191 /* For an inequality constraint
1192  *
1193  *      f >= 0
1194  *
1195  * or an equality constraint
1196  *
1197  *      f = 0
1198  *
1199  * return the affine expression f.
1200  */
1201 __isl_give isl_aff *isl_constraint_get_aff(
1202         __isl_keep isl_constraint *constraint)
1203 {
1204         isl_aff *aff;
1205
1206         if (!constraint)
1207                 return NULL;
1208
1209         aff = isl_aff_alloc(isl_local_space_copy(constraint->ls));
1210         if (!aff)
1211                 return NULL;
1212
1213         isl_seq_cpy(aff->v->el + 1, constraint->v->el, aff->v->size - 1);
1214         isl_int_set_si(aff->v->el[0], 1);
1215
1216         return aff;
1217 }
1218
1219 /* Construct an equality constraint equating the given affine expression
1220  * to zero.
1221  */
1222 __isl_give isl_constraint *isl_equality_from_aff(__isl_take isl_aff *aff)
1223 {
1224         int k;
1225         isl_local_space *ls;
1226         isl_basic_set *bset;
1227
1228         if (!aff)
1229                 return NULL;
1230
1231         ls = isl_aff_get_domain_local_space(aff);
1232         bset = isl_basic_set_from_local_space(ls);
1233         bset = isl_basic_set_extend_constraints(bset, 1, 0);
1234         k = isl_basic_set_alloc_equality(bset);
1235         if (k < 0)
1236                 goto error;
1237
1238         isl_seq_cpy(bset->eq[k], aff->v->el + 1, aff->v->size - 1);
1239         isl_aff_free(aff);
1240
1241         return isl_basic_set_constraint(bset, &bset->eq[k]);
1242 error:
1243         isl_aff_free(aff);
1244         isl_basic_set_free(bset);
1245         return NULL;
1246 }
1247
1248 /* Construct an inequality constraint enforcing the given affine expression
1249  * to be non-negative.
1250  */
1251 __isl_give isl_constraint *isl_inequality_from_aff(__isl_take isl_aff *aff)
1252 {
1253         int k;
1254         isl_local_space *ls;
1255         isl_basic_set *bset;
1256
1257         if (!aff)
1258                 return NULL;
1259
1260         ls = isl_aff_get_domain_local_space(aff);
1261         bset = isl_basic_set_from_local_space(ls);
1262         bset = isl_basic_set_extend_constraints(bset, 0, 1);
1263         k = isl_basic_set_alloc_inequality(bset);
1264         if (k < 0)
1265                 goto error;
1266
1267         isl_seq_cpy(bset->ineq[k], aff->v->el + 1, aff->v->size - 1);
1268         isl_aff_free(aff);
1269
1270         return isl_basic_set_constraint(bset, &bset->ineq[k]);
1271 error:
1272         isl_aff_free(aff);
1273         isl_basic_set_free(bset);
1274         return NULL;
1275 }