isl_constraint.c

   1 /*
   2  * Copyright 2008-2009 Katholieke Universiteit Leuven
   3  *
   4  * Use of this software is governed by the GNU LGPLv2.1 license
   5  *
   6  * Written by Sven Verdoolaege, K.U.Leuven, Departement
   7  * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
   8  */
   9
  10 #include <isl_constraint.h>
  11 #include "isl_seq.h"
  12 #include "isl_map_private.h"
  13
  14 static unsigned n(struct isl_constraint *c, enum isl_dim_type type)
  15 {
  16         return isl_basic_map_dim(c->bmap, type);
  17 }
  18
  19 static unsigned offset(struct isl_constraint *c, enum isl_dim_type type)
  20 {
  21         struct isl_dim *dim = c->bmap->dim;
  22         switch (type) {
  23         case isl_dim_param:     return 1;
  24         case isl_dim_in:        return 1 + dim->nparam;
  25         case isl_dim_out:       return 1 + dim->nparam + dim->n_in;
  26         case isl_dim_div:       return 1 + dim->nparam + dim->n_in + dim->n_out;
  27         }
  28 }
  29
  30 static unsigned basic_set_offset(struct isl_basic_set *bset,
  31                                                         enum isl_dim_type type)
  32 {
  33         struct isl_dim *dim = bset->dim;
  34         switch (type) {
  35         case isl_dim_param:     return 1;
  36         case isl_dim_in:        return 1 + dim->nparam;
  37         case isl_dim_out:       return 1 + dim->nparam + dim->n_in;
  38         case isl_dim_div:       return 1 + dim->nparam + dim->n_in + dim->n_out;
  39         }
  40 }
  41
  42 struct isl_constraint *isl_basic_map_constraint(struct isl_basic_map *bmap,
  43         isl_int **line)
  44 {
  45         struct isl_constraint *constraint;
  46
  47         if (!bmap || !line)
  48                 goto error;
  49
  50         constraint = isl_alloc_type(bmap->ctx, struct isl_constraint);
  51         if (!constraint)
  52                 goto error;
  53
  54         constraint->ctx = bmap->ctx;
  55         isl_ctx_ref(constraint->ctx);
  56         constraint->ref = 1;
  57         constraint->bmap = bmap;
  58         constraint->line = line;
  59
  60         return constraint;
  61 error:
  62         isl_basic_map_free(bmap);
  63         return NULL;
  64 }
  65
  66 struct isl_constraint *isl_basic_set_constraint(struct isl_basic_set *bset,
  67         isl_int **line)
  68 {
  69         return isl_basic_map_constraint((struct isl_basic_map *)bset, line);
  70 }
  71
  72 struct isl_constraint *isl_equality_alloc(struct isl_dim *dim)
  73 {
  74         struct isl_basic_map *bmap;
  75
  76         if (!dim)
  77                 return NULL;
  78
  79         bmap = isl_basic_map_alloc_dim(dim, 0, 1, 0);
  80         if (!bmap)
  81                 return NULL;
  82
  83         isl_basic_map_alloc_equality(bmap);
  84         isl_seq_clr(bmap->eq[0], 1 + isl_basic_map_total_dim(bmap));
  85         return isl_basic_map_constraint(bmap, &bmap->eq[0]);
  86 }
  87
  88 struct isl_constraint *isl_inequality_alloc(struct isl_dim *dim)
  89 {
  90         struct isl_basic_map *bmap;
  91
  92         if (!dim)
  93                 return NULL;
  94
  95         bmap = isl_basic_map_alloc_dim(dim, 0, 0, 1);
  96         if (!bmap)
  97                 return NULL;
  98
  99         isl_basic_map_alloc_inequality(bmap);
 100         isl_seq_clr(bmap->ineq[0], 1 + isl_basic_map_total_dim(bmap));
 101         return isl_basic_map_constraint(bmap, &bmap->ineq[0]);
 102 }
 103
 104 struct isl_constraint *isl_constraint_dup(struct isl_constraint *c)
 105 {
 106         struct isl_basic_map *bmap;
 107         int i;
 108         int eq;
 109
 110         if (!c)
 111                 return NULL;
 112
 113         eq = c->line < c->bmap->eq + c->bmap->n_eq;
 114         i = eq ? c->line - c->bmap->eq : c->line - c->bmap->ineq;
 115         bmap = isl_basic_map_copy(c->bmap);
 116         if (!bmap)
 117                 return NULL;
 118         return isl_basic_map_constraint(bmap, eq ? bmap->eq + i : bmap->ineq + i);
 119 }
 120
 121 struct isl_constraint *isl_constraint_cow(struct isl_constraint *c)
 122 {
 123         if (!c)
 124                 return NULL;
 125
 126         if (c->ref == 1)
 127                 return c;
 128         c->ref--;
 129         return isl_constraint_dup(c);
 130 }
 131
 132 struct isl_constraint *isl_constraint_copy(struct isl_constraint *constraint)
 133 {
 134         if (!constraint)
 135                 return NULL;
 136
 137         constraint->ref++;
 138         return constraint;
 139 }
 140
 141 void isl_constraint_free(struct isl_constraint *c)
 142 {
 143         if (!c)
 144                 return;
 145
 146         if (--c->ref > 0)
 147                 return;
 148
 149         isl_basic_map_free(c->bmap);
 150         isl_ctx_deref(c->ctx);
 151         free(c);
 152 }
 153
 154 __isl_give isl_constraint *isl_basic_map_first_constraint(
 155         __isl_take isl_basic_map *bmap)
 156 {
 157         if (!bmap)
 158                 return NULL;
 159
 160         if (bmap->n_eq > 0)
 161                 return isl_basic_map_constraint(bmap, &bmap->eq[0]);
 162
 163         if (bmap->n_ineq > 0)
 164                 return isl_basic_map_constraint(bmap, &bmap->ineq[0]);
 165
 166         isl_basic_map_free(bmap);
 167         return NULL;
 168 }
 169
 170 __isl_give isl_constraint *isl_basic_set_first_constraint(
 171         __isl_take isl_basic_set *bset)
 172 {
 173         return isl_basic_map_first_constraint((struct isl_basic_map *)bset);
 174 }
 175
 176 struct isl_constraint *isl_constraint_next(struct isl_constraint *c)
 177 {
 178         c = isl_constraint_cow(c);
 179         if (c->line >= c->bmap->eq) {
 180                 c->line++;
 181                 if (c->line < c->bmap->eq + c->bmap->n_eq)
 182                         return c;
 183                 c->line = c->bmap->ineq;
 184         } else
 185                 c->line++;
 186         if (c->line < c->bmap->ineq + c->bmap->n_ineq)
 187                 return c;
 188         isl_constraint_free(c);
 189         return NULL;
 190 }
 191
 192 int isl_basic_map_foreach_constraint(__isl_keep isl_basic_map *bmap,
 193         int (*fn)(__isl_take isl_constraint *c, void *user), void *user)
 194 {
 195         int i;
 196         struct isl_constraint *c;
 197
 198         if (!bmap)
 199                 return -1;
 200
 201         for (i = 0; i < bmap->n_eq; ++i) {
 202                 c = isl_basic_map_constraint(isl_basic_map_copy(bmap),
 203                                                 &bmap->eq[i]);
 204                 if (!c)
 205                         return -1;
 206                 if (fn(c, user) < 0)
 207                         return -1;
 208         }
 209
 210         for (i = 0; i < bmap->n_ineq; ++i) {
 211                 c = isl_basic_map_constraint(isl_basic_map_copy(bmap),
 212                                                 &bmap->ineq[i]);
 213                 if (!c)
 214                         return -1;
 215                 if (fn(c, user) < 0)
 216                         return -1;
 217         }
 218
 219         return 0;
 220 }
 221
 222 int isl_basic_set_foreach_constraint(__isl_keep isl_basic_set *bset,
 223         int (*fn)(__isl_take isl_constraint *c, void *user), void *user)
 224 {
 225         return isl_basic_map_foreach_constraint((isl_basic_map *)bset, fn, user);
 226 }
 227
 228 int isl_constraint_is_equal(struct isl_constraint *constraint1,
 229         struct isl_constraint *constraint2)
 230 {
 231         if (!constraint1 || !constraint2)
 232                 return 0;
 233         return constraint1->bmap == constraint2->bmap &&
 234                constraint1->line == constraint2->line;
 235 }
 236
 237 struct isl_basic_map *isl_basic_map_add_constraint(
 238         struct isl_basic_map *bmap, struct isl_constraint *constraint)
 239 {
 240         if (!bmap || !constraint)
 241                 goto error;
 242
 243         isl_assert(constraint->ctx,
 244                 isl_dim_equal(bmap->dim, constraint->bmap->dim), goto error);
 245
 246         bmap = isl_basic_map_intersect(bmap,
 247                                 isl_basic_map_from_constraint(constraint));
 248         return bmap;
 249 error:
 250         isl_basic_map_free(bmap);
 251         isl_constraint_free(constraint);
 252         return NULL;
 253 }
 254
 255 struct isl_basic_set *isl_basic_set_add_constraint(
 256         struct isl_basic_set *bset, struct isl_constraint *constraint)
 257 {
 258         return (struct isl_basic_set *)
 259                 isl_basic_map_add_constraint((struct isl_basic_map *)bset,
 260                                                 constraint);
 261 }
 262
 263 struct isl_constraint *isl_constraint_add_div(struct isl_constraint *constraint,
 264         struct isl_div *div, int *pos)
 265 {
 266         if (!constraint || !div)
 267                 goto error;
 268
 269         isl_assert(constraint->ctx,
 270             isl_dim_equal(div->bmap->dim, constraint->bmap->dim), goto error);
 271         isl_assert(constraint->ctx,
 272             constraint->bmap->n_eq + constraint->bmap->n_ineq == 1, goto error);
 273
 274         constraint->bmap = isl_basic_map_cow(constraint->bmap);
 275         constraint->bmap = isl_basic_map_extend_dim(constraint->bmap,
 276                                 isl_dim_copy(constraint->bmap->dim), 1, 0, 0);
 277         if (!constraint->bmap)
 278                 goto error;
 279         constraint->line = &constraint->bmap->eq[0];
 280         *pos = isl_basic_map_alloc_div(constraint->bmap);
 281         if (*pos < 0)
 282                 goto error;
 283         isl_seq_cpy(constraint->bmap->div[*pos], div->line[0],
 284                         1 + 1 + isl_basic_map_total_dim(constraint->bmap));
 285         isl_div_free(div);
 286         return constraint;
 287 error:
 288         isl_constraint_free(constraint);
 289         isl_div_free(div);
 290         return NULL;
 291 }
 292
 293 int isl_constraint_dim(struct isl_constraint *constraint,
 294         enum isl_dim_type type)
 295 {
 296         if (!constraint)
 297                 return -1;
 298         return n(constraint, type);
 299 }
 300
 301 void isl_constraint_get_constant(struct isl_constraint *constraint, isl_int *v)
 302 {
 303         if (!constraint)
 304                 return;
 305         isl_int_set(*v, constraint->line[0][0]);
 306 }
 307
 308 void isl_constraint_get_coefficient(struct isl_constraint *constraint,
 309         enum isl_dim_type type, int pos, isl_int *v)
 310 {
 311         if (!constraint)
 312                 return;
 313
 314         isl_assert(constraint->ctx, pos < n(constraint, type), return);
 315         isl_int_set(*v, constraint->line[0][offset(constraint, type) + pos]);
 316 }
 317
 318 struct isl_div *isl_constraint_div(struct isl_constraint *constraint, int pos)
 319 {
 320         if (!constraint)
 321                 return NULL;
 322
 323         isl_assert(constraint->ctx, pos < n(constraint, isl_dim_div),
 324                         return NULL);
 325         return isl_basic_map_div(isl_basic_map_copy(constraint->bmap), pos);
 326 }
 327
 328 void isl_constraint_set_constant(struct isl_constraint *constraint, isl_int v)
 329 {
 330         if (!constraint)
 331                 return;
 332         isl_int_set(constraint->line[0][0], v);
 333 }
 334
 335 void isl_constraint_set_coefficient(struct isl_constraint *constraint,
 336         enum isl_dim_type type, int pos, isl_int v)
 337 {
 338         if (!constraint)
 339                 return;
 340
 341         isl_assert(constraint->ctx, pos < n(constraint, type), return);
 342         isl_int_set(constraint->line[0][offset(constraint, type) + pos], v);
 343 }
 344
 345 void isl_constraint_clear(struct isl_constraint *constraint)
 346 {
 347         unsigned total;
 348
 349         if (!constraint)
 350                 return;
 351         total = isl_basic_map_total_dim(constraint->bmap);
 352         isl_seq_clr(constraint->line[0], 1 + total);
 353 }
 354
 355 struct isl_constraint *isl_constraint_negate(struct isl_constraint *constraint)
 356 {
 357         unsigned total;
 358
 359         if (!constraint)
 360                 return NULL;
 361
 362         isl_assert(constraint->ctx, !isl_constraint_is_equality(constraint),
 363                         goto error);
 364         isl_assert(constraint->ctx, constraint->bmap->ref == 1, goto error);
 365         total = isl_basic_map_total_dim(constraint->bmap);
 366         isl_seq_neg(constraint->line[0], constraint->line[0], 1 + total);
 367         isl_int_sub_ui(constraint->line[0][0], constraint->line[0][0], 1);
 368         ISL_F_CLR(constraint->bmap, ISL_BASIC_MAP_NORMALIZED);
 369         return constraint;
 370 error:
 371         isl_constraint_free(constraint);
 372         return NULL;
 373 }
 374
 375 int isl_constraint_is_equality(struct isl_constraint *constraint)
 376 {
 377         if (!constraint)
 378                 return -1;
 379         return constraint->line >= constraint->bmap->eq;
 380 }
 381
 382 __isl_give isl_basic_map *isl_basic_map_from_constraint(
 383         __isl_take isl_constraint *constraint)
 384 {
 385         int k;
 386         struct isl_basic_map *bmap;
 387         isl_int *c;
 388         unsigned total;
 389
 390         if (!constraint)
 391                 return NULL;
 392
 393         if (constraint->bmap->n_eq + constraint->bmap->n_ineq == 1) {
 394                 bmap = isl_basic_map_copy(constraint->bmap);
 395                 isl_constraint_free(constraint);
 396                 return bmap;
 397         }
 398
 399         bmap = isl_basic_map_universe_like(constraint->bmap);
 400         bmap = isl_basic_map_align_divs(bmap, constraint->bmap);
 401         bmap = isl_basic_map_cow(bmap);
 402         bmap = isl_basic_map_extend_constraints(bmap, 1, 1);
 403         if (isl_constraint_is_equality(constraint)) {
 404                 k = isl_basic_map_alloc_equality(bmap);
 405                 if (k < 0)
 406                         goto error;
 407                 c = bmap->eq[k];
 408         }
 409         else {
 410                 k = isl_basic_map_alloc_inequality(bmap);
 411                 if (k < 0)
 412                         goto error;
 413                 c = bmap->ineq[k];
 414         }
 415         total = isl_basic_map_total_dim(bmap);
 416         isl_seq_cpy(c, constraint->line[0], 1 + total);
 417         isl_constraint_free(constraint);
 418         return bmap;
 419 error:
 420         isl_constraint_free(constraint);
 421         isl_basic_map_free(bmap);
 422         return NULL;
 423 }
 424
 425 struct isl_basic_set *isl_basic_set_from_constraint(
 426         struct isl_constraint *constraint)
 427 {
 428         if (!constraint)
 429                 return NULL;
 430
 431         isl_assert(constraint->ctx,n(constraint, isl_dim_in) == 0, goto error);
 432         return (isl_basic_set *)isl_basic_map_from_constraint(constraint);
 433 error:
 434         isl_constraint_free(constraint);
 435         return NULL;
 436 }
 437
 438 int isl_basic_set_has_defining_equality(
 439         struct isl_basic_set *bset, enum isl_dim_type type, int pos,
 440         struct isl_constraint **c)
 441 {
 442         int i;
 443         unsigned offset;
 444         unsigned total;
 445
 446         if (!bset)
 447                 return -1;
 448         offset = basic_set_offset(bset, type);
 449         total = isl_basic_set_total_dim(bset);
 450         isl_assert(bset->ctx, pos < isl_basic_set_dim(bset, type), return -1);
 451         for (i = 0; i < bset->n_eq; ++i)
 452                 if (!isl_int_is_zero(bset->eq[i][offset + pos]) &&
 453                     isl_seq_first_non_zero(bset->eq[i]+offset+pos+1,
 454                                            1+total-offset-pos-1) == -1) {
 455                         *c= isl_basic_set_constraint(isl_basic_set_copy(bset),
 456                                                                 &bset->eq[i]);
 457                         return 1;
 458                 }
 459         return 0;
 460 }
 461
 462 int isl_basic_set_has_defining_inequalities(
 463         struct isl_basic_set *bset, enum isl_dim_type type, int pos,
 464         struct isl_constraint **lower,
 465         struct isl_constraint **upper)
 466 {
 467         int i, j;
 468         unsigned offset;
 469         unsigned total;
 470         isl_int m;
 471         isl_int **lower_line, **upper_line;
 472
 473         if (!bset)
 474                 return -1;
 475         offset = basic_set_offset(bset, type);
 476         total = isl_basic_set_total_dim(bset);
 477         isl_assert(bset->ctx, pos < isl_basic_set_dim(bset, type), return -1);
 478         isl_int_init(m);
 479         for (i = 0; i < bset->n_ineq; ++i) {
 480                 if (isl_int_is_zero(bset->ineq[i][offset + pos]))
 481                         continue;
 482                 if (isl_int_is_one(bset->ineq[i][offset + pos]))
 483                         continue;
 484                 if (isl_int_is_negone(bset->ineq[i][offset + pos]))
 485                         continue;
 486                 if (isl_seq_first_non_zero(bset->ineq[i]+offset+pos+1,
 487                                                 1+total-offset-pos-1) != -1)
 488                         continue;
 489                 for (j = i + 1; j < bset->n_ineq; ++j) {
 490                         if (!isl_seq_is_neg(bset->ineq[i]+1, bset->ineq[j]+1,
 491                                             total))
 492                                 continue;
 493                         isl_int_add(m, bset->ineq[i][0], bset->ineq[j][0]);
 494                         if (isl_int_abs_ge(m, bset->ineq[i][offset+pos]))
 495                                 continue;
 496
 497                         if (isl_int_is_pos(bset->ineq[i][offset+pos])) {
 498                                 lower_line = &bset->ineq[i];
 499                                 upper_line = &bset->ineq[j];
 500                         } else {
 501                                 lower_line = &bset->ineq[j];
 502                                 upper_line = &bset->ineq[i];
 503                         }
 504                         *lower = isl_basic_set_constraint(
 505                                         isl_basic_set_copy(bset), lower_line);
 506                         *upper = isl_basic_set_constraint(
 507                                         isl_basic_set_copy(bset), upper_line);
 508                         isl_int_clear(m);
 509                         return 1;
 510                 }
 511         }
 512         *lower = NULL;
 513         *upper = NULL;
 514         isl_int_clear(m);
 515         return 0;
 516 }