isl_dim.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_dim.h>
  11 #include "isl_name.h"
  12
  13 struct isl_dim *isl_dim_alloc(struct isl_ctx *ctx,
  14                         unsigned nparam, unsigned n_in, unsigned n_out)
  15 {
  16         struct isl_dim *dim;
  17
  18         dim = isl_alloc_type(ctx, struct isl_dim);
  19         if (!dim)
  20                 return NULL;
  21
  22         dim->ctx = ctx;
  23         isl_ctx_ref(ctx);
  24         dim->ref = 1;
  25         dim->nparam = nparam;
  26         dim->n_in = n_in;
  27         dim->n_out = n_out;
  28
  29         dim->n_name = 0;
  30         dim->names = NULL;
  31
  32         return dim;
  33 }
  34
  35 struct isl_dim *isl_dim_set_alloc(struct isl_ctx *ctx,
  36                         unsigned nparam, unsigned dim)
  37 {
  38         return isl_dim_alloc(ctx, nparam, 0, dim);
  39 }
  40
  41 static unsigned global_pos(struct isl_dim *dim,
  42                                  enum isl_dim_type type, unsigned pos)
  43 {
  44         struct isl_ctx *ctx = dim->ctx;
  45
  46         switch (type) {
  47         case isl_dim_param:
  48                 isl_assert(ctx, pos < dim->nparam, return isl_dim_total(dim));
  49                 return pos;
  50         case isl_dim_in:
  51                 isl_assert(ctx, pos < dim->n_in, return isl_dim_total(dim));
  52                 return pos + dim->nparam;
  53         case isl_dim_out:
  54                 isl_assert(ctx, pos < dim->n_out, return isl_dim_total(dim));
  55                 return pos + dim->nparam + dim->n_in;
  56         default:
  57                 isl_assert(ctx, 0, return isl_dim_total(dim));
  58         }
  59         return isl_dim_total(dim);
  60 }
  61
  62 /* Extend length of names array to the total number of dimensions.
  63  */
  64 static __isl_give isl_dim *extend_names(__isl_take isl_dim *dim)
  65 {
  66         struct isl_name **names;
  67         int i;
  68
  69         if (isl_dim_total(dim) <= dim->n_name)
  70                 return dim;
  71
  72         if (!dim->names) {
  73                 dim->names = isl_calloc_array(dim->ctx,
  74                                 struct isl_name *, isl_dim_total(dim));
  75                 if (!dim->names)
  76                         goto error;
  77         } else {
  78                 names = isl_realloc_array(dim->ctx, dim->names,
  79                                 struct isl_name *, isl_dim_total(dim));
  80                 if (!names)
  81                         goto error;
  82                 dim->names = names;
  83                 for (i = dim->n_name; i < isl_dim_total(dim); ++i)
  84                         dim->names[i] = NULL;
  85         }
  86
  87         dim->n_name = isl_dim_total(dim);
  88
  89         return dim;
  90 error:
  91         isl_dim_free(dim);
  92         return NULL;
  93 }
  94
  95 static struct isl_dim *set_name(struct isl_dim *dim,
  96                                  enum isl_dim_type type, unsigned pos,
  97                                  struct isl_name *name)
  98 {
  99         struct isl_ctx *ctx = dim->ctx;
 100         dim = isl_dim_cow(dim);
 101
 102         if (!dim)
 103                 goto error;
 104
 105         pos = global_pos(dim, type, pos);
 106         isl_assert(ctx, pos != isl_dim_total(dim), goto error);
 107
 108         if (pos >= dim->n_name) {
 109                 if (!name)
 110                         return dim;
 111                 dim = extend_names(dim);
 112                 if (!dim)
 113                         goto error;
 114         }
 115
 116         dim->names[pos] = name;
 117
 118         return dim;
 119 error:
 120         isl_name_free(ctx, name);
 121         isl_dim_free(dim);
 122         return NULL;
 123 }
 124
 125 static struct isl_name *get_name(struct isl_dim *dim,
 126                                  enum isl_dim_type type, unsigned pos)
 127 {
 128         if (!dim)
 129                 return NULL;
 130
 131         pos = global_pos(dim, type, pos);
 132         if (pos == isl_dim_total(dim))
 133                 return NULL;
 134         if (pos >= dim->n_name)
 135                 return NULL;
 136         return dim->names[pos];
 137 }
 138
 139 static unsigned offset(struct isl_dim *dim, enum isl_dim_type type)
 140 {
 141         switch (type) {
 142         case isl_dim_param:     return 0;
 143         case isl_dim_in:        return dim->nparam;
 144         case isl_dim_out:       return dim->nparam + dim->n_in;
 145         }
 146 }
 147
 148 static unsigned n(struct isl_dim *dim, enum isl_dim_type type)
 149 {
 150         switch (type) {
 151         case isl_dim_param:     return dim->nparam;
 152         case isl_dim_in:        return dim->n_in;
 153         case isl_dim_out:       return dim->n_out;
 154         }
 155 }
 156
 157 unsigned isl_dim_size(struct isl_dim *dim, enum isl_dim_type type)
 158 {
 159         if (!dim)
 160                 return 0;
 161         return n(dim, type);
 162 }
 163
 164 unsigned isl_dim_offset(__isl_keep isl_dim *dim, enum isl_dim_type type)
 165 {
 166         if (!dim)
 167                 return 0;
 168         return offset(dim, type);
 169 }
 170
 171 static struct isl_dim *copy_names(struct isl_dim *dst,
 172         enum isl_dim_type dst_type, unsigned offset, struct isl_dim *src,
 173         enum isl_dim_type src_type)
 174 {
 175         int i;
 176         struct isl_name *name;
 177
 178         for (i = 0; i < n(src, src_type); ++i) {
 179                 name = get_name(src, src_type, i);
 180                 if (!name)
 181                         continue;
 182                 dst = set_name(dst, dst_type, offset + i,
 183                                         isl_name_copy(dst->ctx, name));
 184                 if (!dst)
 185                         return NULL;
 186         }
 187         return dst;
 188 }
 189
 190 struct isl_dim *isl_dim_dup(struct isl_dim *dim)
 191 {
 192         struct isl_dim *dup;
 193         dup = isl_dim_alloc(dim->ctx, dim->nparam, dim->n_in, dim->n_out);
 194         if (!dim->names)
 195                 return dup;
 196         dup = copy_names(dup, isl_dim_param, 0, dim, isl_dim_param);
 197         dup = copy_names(dup, isl_dim_in, 0, dim, isl_dim_in);
 198         dup = copy_names(dup, isl_dim_out, 0, dim, isl_dim_out);
 199         return dup;
 200 }
 201
 202 struct isl_dim *isl_dim_cow(struct isl_dim *dim)
 203 {
 204         if (!dim)
 205                 return NULL;
 206
 207         if (dim->ref == 1)
 208                 return dim;
 209         dim->ref--;
 210         return isl_dim_dup(dim);
 211 }
 212
 213 struct isl_dim *isl_dim_copy(struct isl_dim *dim)
 214 {
 215         if (!dim)
 216                 return NULL;
 217
 218         dim->ref++;
 219         return dim;
 220 }
 221
 222 void isl_dim_free(struct isl_dim *dim)
 223 {
 224         int i;
 225
 226         if (!dim)
 227                 return;
 228
 229         if (--dim->ref > 0)
 230                 return;
 231
 232         for (i = 0; i < dim->n_name; ++i)
 233                 isl_name_free(dim->ctx, dim->names[i]);
 234         free(dim->names);
 235         isl_ctx_deref(dim->ctx);
 236
 237         free(dim);
 238 }
 239
 240 struct isl_dim *isl_dim_set_name(struct isl_dim *dim,
 241                                  enum isl_dim_type type, unsigned pos,
 242                                  const char *s)
 243 {
 244         struct isl_name *name;
 245         if (!dim)
 246                 return NULL;
 247         name = isl_name_get(dim->ctx, s);
 248         if (!name)
 249                 goto error;
 250         return set_name(dim, type, pos, name);
 251 error:
 252         isl_dim_free(dim);
 253         return NULL;
 254 }
 255
 256 const char *isl_dim_get_name(struct isl_dim *dim,
 257                                  enum isl_dim_type type, unsigned pos)
 258 {
 259         struct isl_name *name = get_name(dim, type, pos);
 260         return name ? name->name : NULL;
 261 }
 262
 263 static int match(struct isl_dim *dim1, enum isl_dim_type dim1_type,
 264                 struct isl_dim *dim2, enum isl_dim_type dim2_type)
 265 {
 266         int i;
 267
 268         if (n(dim1, dim1_type) != n(dim2, dim2_type))
 269                 return 0;
 270
 271         if (!dim1->names && !dim2->names)
 272                 return 1;
 273
 274         for (i = 0; i < n(dim1, dim1_type); ++i) {
 275                 if (get_name(dim1, dim1_type, i) !=
 276                     get_name(dim2, dim2_type, i))
 277                         return 0;
 278         }
 279         return 1;
 280 }
 281
 282 int isl_dim_match(struct isl_dim *dim1, enum isl_dim_type dim1_type,
 283                 struct isl_dim *dim2, enum isl_dim_type dim2_type)
 284 {
 285         return match(dim1, dim1_type, dim2, dim2_type);
 286 }
 287
 288 static void get_names(struct isl_dim *dim, enum isl_dim_type type,
 289         unsigned first, unsigned n, struct isl_name **names)
 290 {
 291         int i;
 292
 293         for (i = 0; i < n ; ++i)
 294                 names[i] = get_name(dim, type, first+i);
 295 }
 296
 297 struct isl_dim *isl_dim_extend(struct isl_dim *dim,
 298                         unsigned nparam, unsigned n_in, unsigned n_out)
 299 {
 300         struct isl_name **names = NULL;
 301
 302         if (!dim)
 303                 return NULL;
 304         if (dim->nparam == nparam && dim->n_in == n_in && dim->n_out == n_out)
 305                 return dim;
 306
 307         isl_assert(dim->ctx, dim->nparam <= nparam, goto error);
 308         isl_assert(dim->ctx, dim->n_in <= n_in, goto error);
 309         isl_assert(dim->ctx, dim->n_out <= n_out, goto error);
 310
 311         dim = isl_dim_cow(dim);
 312
 313         if (dim->names) {
 314                 names = isl_calloc_array(dim->ctx, struct isl_name *,
 315                                          nparam + n_in + n_out);
 316                 if (!names)
 317                         goto error;
 318                 get_names(dim, isl_dim_param, 0, dim->nparam, names);
 319                 get_names(dim, isl_dim_in, 0, dim->n_in, names + nparam);
 320                 get_names(dim, isl_dim_out, 0, dim->n_out,
 321                                 names + nparam + n_in);
 322                 free(dim->names);
 323                 dim->names = names;
 324                 dim->n_name = nparam + n_in + n_out;
 325         }
 326         dim->nparam = nparam;
 327         dim->n_in = n_in;
 328         dim->n_out = n_out;
 329
 330         return dim;
 331 error:
 332         free(names);
 333         isl_dim_free(dim);
 334         return NULL;
 335 }
 336
 337 struct isl_dim *isl_dim_add(struct isl_dim *dim, enum isl_dim_type type,
 338         unsigned n)
 339 {
 340         switch (type) {
 341         case isl_dim_param:
 342                 return isl_dim_extend(dim,
 343                                         dim->nparam + n, dim->n_in, dim->n_out);
 344         case isl_dim_in:
 345                 return isl_dim_extend(dim,
 346                                         dim->nparam, dim->n_in + n, dim->n_out);
 347         case isl_dim_out:
 348                 return isl_dim_extend(dim,
 349                                         dim->nparam, dim->n_in, dim->n_out + n);
 350         }
 351         return dim;
 352 }
 353
 354 __isl_give isl_dim *isl_dim_insert(__isl_take isl_dim *dim,
 355         enum isl_dim_type type, unsigned pos, unsigned n)
 356 {
 357         struct isl_name **names = NULL;
 358
 359         if (!dim)
 360                 return NULL;
 361         if (n == 0)
 362                 return dim;
 363
 364         isl_assert(dim->ctx, pos <= isl_dim_size(dim, type), goto error);
 365
 366         dim = isl_dim_cow(dim);
 367         if (!dim)
 368                 return NULL;
 369
 370         if (dim->names) {
 371                 enum isl_dim_type t;
 372                 int off;
 373                 int size[3];
 374                 names = isl_calloc_array(dim->ctx, struct isl_name *,
 375                                      dim->nparam + dim->n_in + dim->n_out + n);
 376                 if (!names)
 377                         goto error;
 378                 off = 0;
 379                 size[isl_dim_param] = dim->nparam;
 380                 size[isl_dim_in] = dim->n_in;
 381                 size[isl_dim_out] = dim->n_out;
 382                 for (t = isl_dim_param; t <= isl_dim_out; ++t) {
 383                         if (t != type) {
 384                                 get_names(dim, t, 0, size[t], names + off);
 385                                 off += size[t];
 386                         } else {
 387                                 get_names(dim, t, 0, pos, names + off);
 388                                 off += pos + n;
 389                                 get_names(dim, t, pos, size[t]-pos, names+off);
 390                                 off += size[t] - pos;
 391                         }
 392                 }
 393                 free(dim->names);
 394                 dim->names = names;
 395                 dim->n_name = dim->nparam + dim->n_in + dim->n_out + n;
 396         }
 397         switch (type) {
 398         case isl_dim_param:     dim->nparam += n; break;
 399         case isl_dim_in:        dim->n_in += n; break;
 400         case isl_dim_out:       dim->n_out += n; break;
 401         }
 402
 403         return dim;
 404 error:
 405         isl_dim_free(dim);
 406         return NULL;
 407 }
 408
 409 __isl_give isl_dim *isl_dim_move(__isl_take isl_dim *dim,
 410         enum isl_dim_type dst_type, unsigned dst_pos,
 411         enum isl_dim_type src_type, unsigned src_pos, unsigned n)
 412 {
 413         if (!dim)
 414                 return NULL;
 415         if (n == 0)
 416                 return dim;
 417
 418         isl_assert(dim->ctx, src_pos + n <= isl_dim_size(dim, src_type),
 419                 goto error);
 420
 421         if (dst_type == src_type && dst_pos == src_pos)
 422                 return dim;
 423
 424         isl_assert(dim->ctx, dst_type != src_type, goto error);
 425
 426         dim = isl_dim_cow(dim);
 427         if (!dim)
 428                 return NULL;
 429
 430         if (dim->names) {
 431                 struct isl_name **names;
 432                 enum isl_dim_type t;
 433                 int off;
 434                 int size[3];
 435                 names = isl_calloc_array(dim->ctx, struct isl_name *,
 436                                          dim->nparam + dim->n_in + dim->n_out);
 437                 if (!names)
 438                         goto error;
 439                 off = 0;
 440                 size[isl_dim_param] = dim->nparam;
 441                 size[isl_dim_in] = dim->n_in;
 442                 size[isl_dim_out] = dim->n_out;
 443                 for (t = isl_dim_param; t <= isl_dim_out; ++t) {
 444                         if (t == dst_type) {
 445                                 get_names(dim, t, 0, dst_pos, names + off);
 446                                 off += dst_pos;
 447                                 get_names(dim, src_type, src_pos, n, names+off);
 448                                 off += n;
 449                                 get_names(dim, t, dst_pos, size[t] - dst_pos,
 450                                                 names + off);
 451                                 off += size[t] - dst_pos;
 452                         } else if (t == src_type) {
 453                                 get_names(dim, t, 0, src_pos, names + off);
 454                                 off += src_pos;
 455                                 get_names(dim, t, src_pos + n,
 456                                             size[t] - src_pos - n, names + off);
 457                                 off += size[t] - src_pos - n;
 458                         } else {
 459                                 get_names(dim, t, 0, size[t], names + off);
 460                                 off += size[t];
 461                         }
 462                 }
 463                 free(dim->names);
 464                 dim->names = names;
 465                 dim->n_name = dim->nparam + dim->n_in + dim->n_out;
 466         }
 467
 468         switch (dst_type) {
 469         case isl_dim_param:     dim->nparam += n; break;
 470         case isl_dim_in:        dim->n_in += n; break;
 471         case isl_dim_out:       dim->n_out += n; break;
 472         }
 473
 474         switch (src_type) {
 475         case isl_dim_param:     dim->nparam -= n; break;
 476         case isl_dim_in:        dim->n_in -= n; break;
 477         case isl_dim_out:       dim->n_out -= n; break;
 478         }
 479
 480         return dim;
 481 error:
 482         isl_dim_free(dim);
 483         return NULL;
 484 }
 485
 486 struct isl_dim *isl_dim_join(struct isl_dim *left, struct isl_dim *right)
 487 {
 488         struct isl_dim *dim;
 489
 490         if (!left || !right)
 491                 goto error;
 492
 493         isl_assert(left->ctx, match(left, isl_dim_param, right, isl_dim_param),
 494                         goto error);
 495         isl_assert(left->ctx, n(left, isl_dim_out) == n(right, isl_dim_in),
 496                         goto error);
 497
 498         dim = isl_dim_alloc(left->ctx, left->nparam, left->n_in, right->n_out);
 499         if (!dim)
 500                 goto error;
 501
 502         dim = copy_names(dim, isl_dim_param, 0, left, isl_dim_param);
 503         dim = copy_names(dim, isl_dim_in, 0, left, isl_dim_in);
 504         dim = copy_names(dim, isl_dim_out, 0, right, isl_dim_out);
 505
 506         isl_dim_free(left);
 507         isl_dim_free(right);
 508
 509         return dim;
 510 error:
 511         isl_dim_free(left);
 512         isl_dim_free(right);
 513         return NULL;
 514 }
 515
 516 struct isl_dim *isl_dim_product(struct isl_dim *left, struct isl_dim *right)
 517 {
 518         struct isl_dim *dim;
 519
 520         if (!left || !right)
 521                 goto error;
 522
 523         isl_assert(left->ctx, match(left, isl_dim_param, right, isl_dim_param),
 524                         goto error);
 525
 526         dim = isl_dim_alloc(left->ctx, left->nparam,
 527                         left->n_in + right->n_in, left->n_out + right->n_out);
 528         if (!dim)
 529                 goto error;
 530
 531         dim = copy_names(dim, isl_dim_param, 0, left, isl_dim_param);
 532         dim = copy_names(dim, isl_dim_in, 0, left, isl_dim_in);
 533         dim = copy_names(dim, isl_dim_in, left->n_in, right, isl_dim_in);
 534         dim = copy_names(dim, isl_dim_out, 0, left, isl_dim_out);
 535         dim = copy_names(dim, isl_dim_out, left->n_out, right, isl_dim_out);
 536
 537         isl_dim_free(left);
 538         isl_dim_free(right);
 539
 540         return dim;
 541 error:
 542         isl_dim_free(left);
 543         isl_dim_free(right);
 544         return NULL;
 545 }
 546
 547 struct isl_dim *isl_dim_map(struct isl_dim *dim)
 548 {
 549         struct isl_name **names = NULL;
 550
 551         if (!dim)
 552                 return NULL;
 553         isl_assert(dim->ctx, dim->n_in == 0, goto error);
 554         if (dim->n_out == 0)
 555                 return dim;
 556         dim = isl_dim_cow(dim);
 557         if (!dim)
 558                 return NULL;
 559         if (dim->names) {
 560                 names = isl_calloc_array(dim->ctx, struct isl_name *,
 561                                         dim->nparam + dim->n_out + dim->n_out);
 562                 if (!names)
 563                         goto error;
 564                 get_names(dim, isl_dim_param, 0, dim->nparam, names);
 565                 get_names(dim, isl_dim_out, 0, dim->n_out, names + dim->nparam);
 566         }
 567         dim->n_in = dim->n_out;
 568         if (names) {
 569                 free(dim->names);
 570                 dim->names = names;
 571                 dim->n_name = dim->nparam + dim->n_out + dim->n_out;
 572                 dim = copy_names(dim, isl_dim_out, 0, dim, isl_dim_in);
 573         }
 574         return dim;
 575 error:
 576         isl_dim_free(dim);
 577         return NULL;
 578 }
 579
 580 static struct isl_dim *set_names(struct isl_dim *dim, enum isl_dim_type type,
 581         unsigned first, unsigned n, struct isl_name **names)
 582 {
 583         int i;
 584
 585         for (i = 0; i < n ; ++i)
 586                 dim = set_name(dim, type, first+i, names[i]);
 587
 588         return dim;
 589 }
 590
 591 struct isl_dim *isl_dim_reverse(struct isl_dim *dim)
 592 {
 593         unsigned t;
 594         struct isl_name **names = NULL;
 595
 596         if (!dim)
 597                 return NULL;
 598         if (match(dim, isl_dim_in, dim, isl_dim_out))
 599                 return dim;
 600
 601         dim = isl_dim_cow(dim);
 602         if (!dim)
 603                 return NULL;
 604
 605         if (dim->names) {
 606                 names = isl_alloc_array(dim->ctx, struct isl_name *,
 607                                         dim->n_in + dim->n_out);
 608                 if (!names)
 609                         goto error;
 610                 get_names(dim, isl_dim_in, 0, dim->n_in, names);
 611                 get_names(dim, isl_dim_out, 0, dim->n_out, names + dim->n_in);
 612         }
 613
 614         t = dim->n_in;
 615         dim->n_in = dim->n_out;
 616         dim->n_out = t;
 617
 618         if (dim->names) {
 619                 dim = set_names(dim, isl_dim_out, 0, dim->n_out, names);
 620                 dim = set_names(dim, isl_dim_in, 0, dim->n_in, names + dim->n_out);
 621                 free(names);
 622         }
 623
 624         return dim;
 625 error:
 626         free(names);
 627         isl_dim_free(dim);
 628         return NULL;
 629 }
 630
 631 struct isl_dim *isl_dim_drop(struct isl_dim *dim, enum isl_dim_type type,
 632                 unsigned first, unsigned num)
 633 {
 634         int i;
 635
 636         if (!dim)
 637                 return NULL;
 638
 639         if (n == 0)
 640                 return dim;
 641
 642         isl_assert(dim->ctx, first + num <= n(dim, type), goto error);
 643         dim = isl_dim_cow(dim);
 644         if (!dim)
 645                 goto error;
 646         if (dim->names) {
 647                 dim = extend_names(dim);
 648                 if (!dim)
 649                         goto error;
 650                 for (i = 0; i < num; ++i)
 651                         isl_name_free(dim->ctx, get_name(dim, type, first+i));
 652                 for (i = first+num; i < n(dim, type); ++i)
 653                         set_name(dim, type, i - num, get_name(dim, type, i));
 654                 switch (type) {
 655                 case isl_dim_param:
 656                         get_names(dim, isl_dim_in, 0, dim->n_in,
 657                                 dim->names + offset(dim, isl_dim_in) - num);
 658                 case isl_dim_in:
 659                         get_names(dim, isl_dim_out, 0, dim->n_out,
 660                                 dim->names + offset(dim, isl_dim_out) - num);
 661                 case isl_dim_out:
 662                         ;
 663                 }
 664                 dim->n_name -= num;
 665         }
 666         switch (type) {
 667         case isl_dim_param:     dim->nparam -= num; break;
 668         case isl_dim_in:        dim->n_in -= num; break;
 669         case isl_dim_out:       dim->n_out -= num; break;
 670         }
 671         return dim;
 672 error:
 673         isl_dim_free(dim);
 674         return NULL;
 675 }
 676
 677 struct isl_dim *isl_dim_drop_inputs(struct isl_dim *dim,
 678                 unsigned first, unsigned n)
 679 {
 680         return isl_dim_drop(dim, isl_dim_in, first, n);
 681 }
 682
 683 struct isl_dim *isl_dim_drop_outputs(struct isl_dim *dim,
 684                 unsigned first, unsigned n)
 685 {
 686         return isl_dim_drop(dim, isl_dim_out, first, n);
 687 }
 688
 689 struct isl_dim *isl_dim_domain(struct isl_dim *dim)
 690 {
 691         if (!dim)
 692                 return NULL;
 693         dim = isl_dim_drop_outputs(dim, 0, dim->n_out);
 694         return isl_dim_reverse(dim);
 695 }
 696
 697 struct isl_dim *isl_dim_range(struct isl_dim *dim)
 698 {
 699         if (!dim)
 700                 return NULL;
 701         return isl_dim_drop_inputs(dim, 0, dim->n_in);
 702 }
 703
 704 struct isl_dim *isl_dim_underlying(struct isl_dim *dim, unsigned n_div)
 705 {
 706         int i;
 707
 708         if (!dim)
 709                 return NULL;
 710         if (n_div == 0 &&
 711             dim->nparam == 0 && dim->n_in == 0 && dim->n_name == 0)
 712                 return dim;
 713         dim = isl_dim_cow(dim);
 714         if (!dim)
 715                 return NULL;
 716         dim->n_out += dim->nparam + dim->n_in + n_div;
 717         dim->nparam = 0;
 718         dim->n_in = 0;
 719
 720         for (i = 0; i < dim->n_name; ++i)
 721                 isl_name_free(dim->ctx, get_name(dim, isl_dim_out, i));
 722         dim->n_name = 0;
 723
 724         return dim;
 725 }
 726
 727 unsigned isl_dim_total(struct isl_dim *dim)
 728 {
 729         return dim->nparam + dim->n_in + dim->n_out;
 730 }
 731
 732 int isl_dim_equal(struct isl_dim *dim1, struct isl_dim *dim2)
 733 {
 734         return match(dim1, isl_dim_param, dim2, isl_dim_param) &&
 735                n(dim1, isl_dim_in) == n(dim2, isl_dim_in) &&
 736                n(dim1, isl_dim_out) == n(dim2, isl_dim_out);
 737 }
 738
 739 int isl_dim_compatible(struct isl_dim *dim1, struct isl_dim *dim2)
 740 {
 741         return dim1->nparam == dim2->nparam &&
 742                dim1->n_in + dim1->n_out == dim2->n_in + dim2->n_out;
 743 }