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_constraint_is_equal(struct isl_constraint *constraint1,
 193         struct isl_constraint *constraint2)
 194 {
 195         if (!constraint1 || !constraint2)
 196                 return 0;
 197         return constraint1->bmap == constraint2->bmap &&
 198                constraint1->line == constraint2->line;
 199 }
 200
 201 struct isl_basic_map *isl_basic_map_add_constraint(
 202         struct isl_basic_map *bmap, struct isl_constraint *constraint)
 203 {
 204         if (!bmap || !constraint)
 205                 goto error;
 206
 207         isl_assert(constraint->ctx,
 208                 isl_dim_equal(bmap->dim, constraint->bmap->dim), goto error);
 209
 210         bmap = isl_basic_map_intersect(bmap,
 211                                 isl_basic_map_from_constraint(constraint));
 212         return bmap;
 213 error:
 214         isl_basic_map_free(bmap);
 215         isl_constraint_free(constraint);
 216         return NULL;
 217 }
 218
 219 struct isl_basic_set *isl_basic_set_add_constraint(
 220         struct isl_basic_set *bset, struct isl_constraint *constraint)
 221 {
 222         return (struct isl_basic_set *)
 223                 isl_basic_map_add_constraint((struct isl_basic_map *)bset,
 224                                                 constraint);
 225 }
 226
 227 struct isl_constraint *isl_constraint_add_div(struct isl_constraint *constraint,
 228         struct isl_div *div, int *pos)
 229 {
 230         if (!constraint || !div)
 231                 goto error;
 232
 233         isl_assert(constraint->ctx,
 234             isl_dim_equal(div->bmap->dim, constraint->bmap->dim), goto error);
 235         isl_assert(constraint->ctx,
 236             constraint->bmap->n_eq + constraint->bmap->n_ineq == 1, goto error);
 237
 238         constraint->bmap = isl_basic_map_cow(constraint->bmap);
 239         constraint->bmap = isl_basic_map_extend_dim(constraint->bmap,
 240                                 isl_dim_copy(constraint->bmap->dim), 1, 0, 0);
 241         if (!constraint->bmap)
 242                 goto error;
 243         constraint->line = &constraint->bmap->eq[0];
 244         *pos = isl_basic_map_alloc_div(constraint->bmap);
 245         if (*pos < 0)
 246                 goto error;
 247         isl_seq_cpy(constraint->bmap->div[*pos], div->line[0],
 248                         1 + 1 + isl_basic_map_total_dim(constraint->bmap));
 249         isl_div_free(div);
 250         return constraint;
 251 error:
 252         isl_constraint_free(constraint);
 253         isl_div_free(div);
 254         return NULL;
 255 }
 256
 257 int isl_constraint_dim(struct isl_constraint *constraint,
 258         enum isl_dim_type type)
 259 {
 260         if (!constraint)
 261                 return -1;
 262         return n(constraint, type);
 263 }
 264
 265 void isl_constraint_get_constant(struct isl_constraint *constraint, isl_int *v)
 266 {
 267         if (!constraint)
 268                 return;
 269         isl_int_set(*v, constraint->line[0][0]);
 270 }
 271
 272 void isl_constraint_get_coefficient(struct isl_constraint *constraint,
 273         enum isl_dim_type type, int pos, isl_int *v)
 274 {
 275         if (!constraint)
 276                 return;
 277
 278         isl_assert(constraint->ctx, pos < n(constraint, type), return);
 279         isl_int_set(*v, constraint->line[0][offset(constraint, type) + pos]);
 280 }
 281
 282 struct isl_div *isl_constraint_div(struct isl_constraint *constraint, int pos)
 283 {
 284         if (!constraint)
 285                 return NULL;
 286
 287         isl_assert(constraint->ctx, pos < n(constraint, isl_dim_div),
 288                         return NULL);
 289         return isl_basic_map_div(isl_basic_map_copy(constraint->bmap), pos);
 290 }
 291
 292 void isl_constraint_set_constant(struct isl_constraint *constraint, isl_int v)
 293 {
 294         if (!constraint)
 295                 return;
 296         isl_int_set(constraint->line[0][0], v);
 297 }
 298
 299 void isl_constraint_set_coefficient(struct isl_constraint *constraint,
 300         enum isl_dim_type type, int pos, isl_int v)
 301 {
 302         if (!constraint)
 303                 return;
 304
 305         isl_assert(constraint->ctx, pos < n(constraint, type), return);
 306         isl_int_set(constraint->line[0][offset(constraint, type) + pos], v);
 307 }
 308
 309 void isl_constraint_clear(struct isl_constraint *constraint)
 310 {
 311         unsigned total;
 312
 313         if (!constraint)
 314                 return;
 315         total = isl_basic_map_total_dim(constraint->bmap);
 316         isl_seq_clr(constraint->line[0], 1 + total);
 317 }
 318
 319 struct isl_constraint *isl_constraint_negate(struct isl_constraint *constraint)
 320 {
 321         unsigned total;
 322
 323         if (!constraint)
 324                 return NULL;
 325
 326         isl_assert(constraint->ctx, !isl_constraint_is_equality(constraint),
 327                         goto error);
 328         isl_assert(constraint->ctx, constraint->bmap->ref == 1, goto error);
 329         total = isl_basic_map_total_dim(constraint->bmap);
 330         isl_seq_neg(constraint->line[0], constraint->line[0], 1 + total);
 331         isl_int_sub_ui(constraint->line[0][0], constraint->line[0][0], 1);
 332         ISL_F_CLR(constraint->bmap, ISL_BASIC_MAP_NORMALIZED);
 333         return constraint;
 334 error:
 335         isl_constraint_free(constraint);
 336         return NULL;
 337 }
 338
 339 int isl_constraint_is_equality(struct isl_constraint *constraint)
 340 {
 341         if (!constraint)
 342                 return -1;
 343         return constraint->line >= constraint->bmap->eq;
 344 }
 345
 346 __isl_give isl_basic_map *isl_basic_map_from_constraint(
 347         __isl_take isl_constraint *constraint)
 348 {
 349         int k;
 350         struct isl_basic_map *bmap;
 351         isl_int *c;
 352         unsigned total;
 353
 354         if (!constraint)
 355                 return NULL;
 356
 357         if (constraint->bmap->n_eq + constraint->bmap->n_ineq == 1) {
 358                 bmap = isl_basic_map_copy(constraint->bmap);
 359                 isl_constraint_free(constraint);
 360                 return bmap;
 361         }
 362
 363         bmap = isl_basic_map_universe_like(constraint->bmap);
 364         bmap = isl_basic_map_align_divs(bmap, constraint->bmap);
 365         bmap = isl_basic_map_cow(bmap);
 366         bmap = isl_basic_map_extend_constraints(bmap, 1, 1);
 367         if (isl_constraint_is_equality(constraint)) {
 368                 k = isl_basic_map_alloc_equality(bmap);
 369                 if (k < 0)
 370                         goto error;
 371                 c = bmap->eq[k];
 372         }
 373         else {
 374                 k = isl_basic_map_alloc_inequality(bmap);
 375                 if (k < 0)
 376                         goto error;
 377                 c = bmap->ineq[k];
 378         }
 379         total = isl_basic_map_total_dim(bmap);
 380         isl_seq_cpy(c, constraint->line[0], 1 + total);
 381         isl_constraint_free(constraint);
 382         return bmap;
 383 error:
 384         isl_constraint_free(constraint);
 385         isl_basic_map_free(bmap);
 386         return NULL;
 387 }
 388
 389 struct isl_basic_set *isl_basic_set_from_constraint(
 390         struct isl_constraint *constraint)
 391 {
 392         if (!constraint)
 393                 return NULL;
 394
 395         isl_assert(constraint->ctx,n(constraint, isl_dim_in) == 0, goto error);
 396         return (isl_basic_set *)isl_basic_map_from_constraint(constraint);
 397 error:
 398         isl_constraint_free(constraint);
 399         return NULL;
 400 }
 401
 402 int isl_basic_set_has_defining_equality(
 403         struct isl_basic_set *bset, enum isl_dim_type type, int pos,
 404         struct isl_constraint **c)
 405 {
 406         int i;
 407         unsigned offset;
 408         unsigned total;
 409
 410         if (!bset)
 411                 return -1;
 412         offset = basic_set_offset(bset, type);
 413         total = isl_basic_set_total_dim(bset);
 414         isl_assert(bset->ctx, pos < isl_basic_set_dim(bset, type), return -1);
 415         for (i = 0; i < bset->n_eq; ++i)
 416                 if (!isl_int_is_zero(bset->eq[i][offset + pos]) &&
 417                     isl_seq_first_non_zero(bset->eq[i]+offset+pos+1,
 418                                            1+total-offset-pos-1) == -1) {
 419                         *c= isl_basic_set_constraint(isl_basic_set_copy(bset),
 420                                                                 &bset->eq[i]);
 421                         return 1;
 422                 }
 423         return 0;
 424 }
 425
 426 int isl_basic_set_has_defining_inequalities(
 427         struct isl_basic_set *bset, enum isl_dim_type type, int pos,
 428         struct isl_constraint **lower,
 429         struct isl_constraint **upper)
 430 {
 431         int i, j;
 432         unsigned offset;
 433         unsigned total;
 434         isl_int m;
 435         isl_int **lower_line, **upper_line;
 436
 437         if (!bset)
 438                 return -1;
 439         offset = basic_set_offset(bset, type);
 440         total = isl_basic_set_total_dim(bset);
 441         isl_assert(bset->ctx, pos < isl_basic_set_dim(bset, type), return -1);
 442         isl_int_init(m);
 443         for (i = 0; i < bset->n_ineq; ++i) {
 444                 if (isl_int_is_zero(bset->ineq[i][offset + pos]))
 445                         continue;
 446                 if (isl_int_is_one(bset->ineq[i][offset + pos]))
 447                         continue;
 448                 if (isl_int_is_negone(bset->ineq[i][offset + pos]))
 449                         continue;
 450                 if (isl_seq_first_non_zero(bset->ineq[i]+offset+pos+1,
 451                                                 1+total-offset-pos-1) != -1)
 452                         continue;
 453                 for (j = i + 1; j < bset->n_ineq; ++j) {
 454                         if (!isl_seq_is_neg(bset->ineq[i]+1, bset->ineq[j]+1,
 455                                             total))
 456                                 continue;
 457                         isl_int_add(m, bset->ineq[i][0], bset->ineq[j][0]);
 458                         if (isl_int_abs_ge(m, bset->ineq[i][offset+pos]))
 459                                 continue;
 460
 461                         if (isl_int_is_pos(bset->ineq[i][offset+pos])) {
 462                                 lower_line = &bset->ineq[i];
 463                                 upper_line = &bset->ineq[j];
 464                         } else {
 465                                 lower_line = &bset->ineq[j];
 466                                 upper_line = &bset->ineq[i];
 467                         }
 468                         *lower = isl_basic_set_constraint(
 469                                         isl_basic_set_copy(bset), lower_line);
 470                         *upper = isl_basic_set_constraint(
 471                                         isl_basic_set_copy(bset), upper_line);
 472                         isl_int_clear(m);
 473                         return 1;
 474                 }
 475         }
 476         *lower = NULL;
 477         *upper = NULL;
 478         isl_int_clear(m);
 479         return 0;
 480 }