isl_schedule.c

   1 /*
   2  * Copyright 2011      INRIA Saclay
   3  * Copyright 2012-2014 Ecole Normale Superieure
   4  *
   5  * Use of this software is governed by the MIT license
   6  *
   7  * Written by Sven Verdoolaege, INRIA Saclay - Ile-de-France,
   8  * Parc Club Orsay Universite, ZAC des vignes, 4 rue Jacques Monod,
   9  * 91893 Orsay, France
  10  * and Ecole Normale Superieure, 45 rue d'Ulm, 75230 Paris, France
  11  */
  12
  13 #include <isl/ctx.h>
  14 #include <isl_aff_private.h>
  15 #include <isl/map.h>
  16 #include <isl/set.h>
  17 #include <isl/schedule.h>
  18 #include <isl/schedule_node.h>
  19 #include <isl_sort.h>
  20 #include <isl_schedule_private.h>
  21 #include <isl_schedule_tree.h>
  22 #include <isl_schedule_node_private.h>
  23 #include <isl_band_private.h>
  24
  25 /* Return a schedule encapsulating the given schedule tree.
  26  *
  27  * We currently only allow schedule trees with a domain as root.
  28  *
  29  * The leaf field is initialized as a leaf node so that it can be
  30  * used to represent leaves in the constructed schedule.
  31  * The reference count is set to -1 since the isl_schedule_tree
  32  * should never be freed.  It is up to the (internal) users of
  33  * these leaves to ensure that they are only used while the schedule
  34  * is still alive.
  35  */
  36 __isl_give isl_schedule *isl_schedule_from_schedule_tree(isl_ctx *ctx,
  37         __isl_take isl_schedule_tree *tree)
  38 {
  39         isl_schedule *schedule;
  40
  41         if (!tree)
  42                 return NULL;
  43         if (isl_schedule_tree_get_type(tree) != isl_schedule_node_domain)
  44                 isl_die(isl_schedule_tree_get_ctx(tree), isl_error_unsupported,
  45                         "root of schedule tree should be a domain",
  46                         goto error);
  47
  48         schedule = isl_calloc_type(ctx, isl_schedule);
  49         if (!schedule)
  50                 goto error;
  51
  52         schedule->leaf.ctx = ctx;
  53         isl_ctx_ref(ctx);
  54         schedule->ref = 1;
  55         schedule->root = tree;
  56         schedule->leaf.ref = -1;
  57         schedule->leaf.type = isl_schedule_node_leaf;
  58
  59         return schedule;
  60 error:
  61         isl_schedule_tree_free(tree);
  62         return NULL;
  63 }
  64
  65 /* Return a pointer to a schedule with as single node
  66  * a domain node with the given domain.
  67  */
  68 __isl_give isl_schedule *isl_schedule_from_domain(
  69         __isl_take isl_union_set *domain)
  70 {
  71         isl_ctx *ctx;
  72         isl_schedule_tree *tree;
  73
  74         ctx = isl_union_set_get_ctx(domain);
  75         tree = isl_schedule_tree_from_domain(domain);
  76         return isl_schedule_from_schedule_tree(ctx, tree);
  77 }
  78
  79 /* Return a pointer to a schedule with as single node
  80  * a domain node with an empty domain.
  81  */
  82 __isl_give isl_schedule *isl_schedule_empty(__isl_take isl_space *space)
  83 {
  84         return isl_schedule_from_domain(isl_union_set_empty(space));
  85 }
  86
  87 /* Return a new reference to "sched".
  88  */
  89 __isl_give isl_schedule *isl_schedule_copy(__isl_keep isl_schedule *sched)
  90 {
  91         if (!sched)
  92                 return NULL;
  93
  94         sched->ref++;
  95         return sched;
  96 }
  97
  98 /* Return an isl_schedule that is equal to "schedule" and that has only
  99  * a single reference.
 100  *
 101  * We only need and support this function when the schedule is represented
 102  * as a schedule tree.
 103  */
 104 __isl_give isl_schedule *isl_schedule_cow(__isl_take isl_schedule *schedule)
 105 {
 106         isl_ctx *ctx;
 107         isl_schedule_tree *tree;
 108
 109         if (!schedule)
 110                 return NULL;
 111         if (schedule->ref == 1)
 112                 return schedule;
 113
 114         ctx = isl_schedule_get_ctx(schedule);
 115         if (!schedule->root)
 116                 isl_die(ctx, isl_error_internal,
 117                         "only for schedule tree based schedules",
 118                         return isl_schedule_free(schedule));
 119         schedule->ref--;
 120         tree = isl_schedule_tree_copy(schedule->root);
 121         return isl_schedule_from_schedule_tree(ctx, tree);
 122 }
 123
 124 __isl_null isl_schedule *isl_schedule_free(__isl_take isl_schedule *sched)
 125 {
 126         if (!sched)
 127                 return NULL;
 128
 129         if (--sched->ref > 0)
 130                 return NULL;
 131
 132         isl_band_list_free(sched->band_forest);
 133         isl_schedule_tree_free(sched->root);
 134         isl_ctx_deref(sched->leaf.ctx);
 135         free(sched);
 136         return NULL;
 137 }
 138
 139 /* Replace the root of "schedule" by "tree".
 140  */
 141 __isl_give isl_schedule *isl_schedule_set_root(
 142         __isl_take isl_schedule *schedule, __isl_take isl_schedule_tree *tree)
 143 {
 144         if (!schedule || !tree)
 145                 goto error;
 146         if (schedule->root == tree) {
 147                 isl_schedule_tree_free(tree);
 148                 return schedule;
 149         }
 150
 151         schedule = isl_schedule_cow(schedule);
 152         if (!schedule)
 153                 goto error;
 154         isl_schedule_tree_free(schedule->root);
 155         schedule->root = tree;
 156
 157         return schedule;
 158 error:
 159         isl_schedule_free(schedule);
 160         isl_schedule_tree_free(tree);
 161         return NULL;
 162 }
 163
 164 isl_ctx *isl_schedule_get_ctx(__isl_keep isl_schedule *schedule)
 165 {
 166         return schedule ? schedule->leaf.ctx : NULL;
 167 }
 168
 169 /* Return a pointer to the leaf of "schedule".
 170  *
 171  * Even though these leaves are not reference counted, we still
 172  * indicate that this function does not return a copy.
 173  */
 174 __isl_keep isl_schedule_tree *isl_schedule_peek_leaf(
 175         __isl_keep isl_schedule *schedule)
 176 {
 177         return schedule ? &schedule->leaf : NULL;
 178 }
 179
 180 /* Are "schedule1" and "schedule2" obviously equal to each other?
 181  */
 182 int isl_schedule_plain_is_equal(__isl_keep isl_schedule *schedule1,
 183         __isl_keep isl_schedule *schedule2)
 184 {
 185         if (!schedule1 || !schedule2)
 186                 return -1;
 187         if (schedule1 == schedule2)
 188                 return 1;
 189         return isl_schedule_tree_plain_is_equal(schedule1->root,
 190                                                 schedule2->root);
 191 }
 192
 193 /* Return the (parameter) space of the schedule, i.e., the space
 194  * of the root domain.
 195  */
 196 __isl_give isl_space *isl_schedule_get_space(
 197         __isl_keep isl_schedule *schedule)
 198 {
 199         enum isl_schedule_node_type type;
 200         isl_space *space;
 201         isl_union_set *domain;
 202
 203         if (!schedule)
 204                 return NULL;
 205         if (!schedule->root)
 206                 isl_die(isl_schedule_get_ctx(schedule), isl_error_invalid,
 207                         "schedule tree representation not available",
 208                         return NULL);
 209         type = isl_schedule_tree_get_type(schedule->root);
 210         if (type != isl_schedule_node_domain)
 211                 isl_die(isl_schedule_get_ctx(schedule), isl_error_internal,
 212                         "root node not a domain node", return NULL);
 213
 214         domain = isl_schedule_tree_domain_get_domain(schedule->root);
 215         space = isl_union_set_get_space(domain);
 216         isl_union_set_free(domain);
 217
 218         return space;
 219 }
 220
 221 /* Return a pointer to the root of "schedule".
 222  */
 223 __isl_give isl_schedule_node *isl_schedule_get_root(
 224         __isl_keep isl_schedule *schedule)
 225 {
 226         isl_ctx *ctx;
 227         isl_schedule_tree *tree;
 228         isl_schedule_tree_list *ancestors;
 229
 230         if (!schedule)
 231                 return NULL;
 232
 233         if (!schedule->root)
 234                 isl_die(isl_schedule_get_ctx(schedule), isl_error_invalid,
 235                         "schedule tree representation not available",
 236                         return NULL);
 237
 238         ctx = isl_schedule_get_ctx(schedule);
 239         tree = isl_schedule_tree_copy(schedule->root);
 240         schedule = isl_schedule_copy(schedule);
 241         ancestors = isl_schedule_tree_list_alloc(ctx, 0);
 242         return isl_schedule_node_alloc(schedule, tree, ancestors, NULL);
 243 }
 244
 245 /* Set max_out to the maximal number of output dimensions over
 246  * all maps.
 247  */
 248 static int update_max_out(__isl_take isl_map *map, void *user)
 249 {
 250         int *max_out = user;
 251         int n_out = isl_map_dim(map, isl_dim_out);
 252
 253         if (n_out > *max_out)
 254                 *max_out = n_out;
 255
 256         isl_map_free(map);
 257         return 0;
 258 }
 259
 260 /* Internal data structure for map_pad_range.
 261  *
 262  * "max_out" is the maximal schedule dimension.
 263  * "res" collects the results.
 264  */
 265 struct isl_pad_schedule_map_data {
 266         int max_out;
 267         isl_union_map *res;
 268 };
 269
 270 /* Pad the range of the given map with zeros to data->max_out and
 271  * then add the result to data->res.
 272  */
 273 static int map_pad_range(__isl_take isl_map *map, void *user)
 274 {
 275         struct isl_pad_schedule_map_data *data = user;
 276         int i;
 277         int n_out = isl_map_dim(map, isl_dim_out);
 278
 279         map = isl_map_add_dims(map, isl_dim_out, data->max_out - n_out);
 280         for (i = n_out; i < data->max_out; ++i)
 281                 map = isl_map_fix_si(map, isl_dim_out, i, 0);
 282
 283         data->res = isl_union_map_add_map(data->res, map);
 284         if (!data->res)
 285                 return -1;
 286
 287         return 0;
 288 }
 289
 290 /* Pad the ranges of the maps in the union map with zeros such they all have
 291  * the same dimension.
 292  */
 293 static __isl_give isl_union_map *pad_schedule_map(
 294         __isl_take isl_union_map *umap)
 295 {
 296         struct isl_pad_schedule_map_data data;
 297
 298         if (!umap)
 299                 return NULL;
 300         if (isl_union_map_n_map(umap) <= 1)
 301                 return umap;
 302
 303         data.max_out = 0;
 304         if (isl_union_map_foreach_map(umap, &update_max_out, &data.max_out) < 0)
 305                 return isl_union_map_free(umap);
 306
 307         data.res = isl_union_map_empty(isl_union_map_get_space(umap));
 308         if (isl_union_map_foreach_map(umap, &map_pad_range, &data) < 0)
 309                 data.res = isl_union_map_free(data.res);
 310
 311         isl_union_map_free(umap);
 312         return data.res;
 313 }
 314
 315 /* Return the domain of the root domain node of "schedule".
 316  */
 317 __isl_give isl_union_set *isl_schedule_get_domain(
 318         __isl_keep isl_schedule *schedule)
 319 {
 320         if (!schedule)
 321                 return NULL;
 322         if (!schedule->root)
 323                 isl_die(isl_schedule_get_ctx(schedule), isl_error_invalid,
 324                         "schedule tree representation not available",
 325                         return NULL);
 326         return isl_schedule_tree_domain_get_domain(schedule->root);
 327 }
 328
 329 /* Traverse all nodes of "sched" in depth first preorder.
 330  *
 331  * If "fn" returns -1 on any of the nodes, then the traversal is aborted.
 332  * If "fn" returns 0 on any of the nodes, then the subtree rooted
 333  * at that node is skipped.
 334  *
 335  * Return 0 on success and -1 on failure.
 336  */
 337 int isl_schedule_foreach_schedule_node(__isl_keep isl_schedule *sched,
 338         int (*fn)(__isl_keep isl_schedule_node *node, void *user), void *user)
 339 {
 340         isl_schedule_node *node;
 341         int r;
 342
 343         if (!sched)
 344                 return -1;
 345
 346         node = isl_schedule_get_root(sched);
 347         r = isl_schedule_node_foreach_descendant(node, fn, user);
 348         isl_schedule_node_free(node);
 349
 350         return r;
 351 }
 352
 353 /* Traverse the node of "sched" in depth first postorder,
 354  * allowing the user to modify the visited node.
 355  * The traversal continues from the node returned by the callback function.
 356  * It is the responsibility of the user to ensure that this does not
 357  * lead to an infinite loop.  It is safest to always return a pointer
 358  * to the same position (same ancestors and child positions) as the input node.
 359  */
 360 __isl_give isl_schedule *isl_schedule_map_schedule_node(
 361         __isl_take isl_schedule *schedule,
 362         __isl_give isl_schedule_node *(*fn)(
 363                 __isl_take isl_schedule_node *node, void *user), void *user)
 364 {
 365         isl_schedule_node *node;
 366
 367         node = isl_schedule_get_root(schedule);
 368         isl_schedule_free(schedule);
 369
 370         node = isl_schedule_node_map_descendant(node, fn, user);
 371         schedule = isl_schedule_node_get_schedule(node);
 372         isl_schedule_node_free(node);
 373
 374         return schedule;
 375 }
 376
 377 /* Wrapper around isl_schedule_node_reset_user for use as
 378  * an isl_schedule_map_schedule_node callback.
 379  */
 380 static __isl_give isl_schedule_node *reset_user(
 381         __isl_take isl_schedule_node *node, void *user)
 382 {
 383         return isl_schedule_node_reset_user(node);
 384 }
 385
 386 /* Reset the user pointer on all identifiers of parameters and tuples
 387  * in the schedule "schedule".
 388  */
 389 __isl_give isl_schedule *isl_schedule_reset_user(
 390         __isl_take isl_schedule *schedule)
 391 {
 392         return isl_schedule_map_schedule_node(schedule, &reset_user, NULL);
 393 }
 394
 395 /* Return an isl_union_map representation of the schedule.
 396  * If we still have access to the schedule tree, then we return
 397  * an isl_union_map corresponding to the subtree schedule of the child
 398  * of the root domain node.  That is, we do not intersect the domain
 399  * of the returned isl_union_map with the domain constraints.
 400  * Otherwise, we must have removed it because we created a band forest.
 401  * If so, we extract the isl_union_map from the forest.
 402  * This reconstructed schedule map
 403  * then needs to be padded with zeros to unify the schedule space
 404  * since the result of isl_band_list_get_suffix_schedule may not have
 405  * a unified schedule space.
 406  */
 407 __isl_give isl_union_map *isl_schedule_get_map(__isl_keep isl_schedule *sched)
 408 {
 409         enum isl_schedule_node_type type;
 410         isl_schedule_node *node;
 411         isl_union_map *umap;
 412
 413         if (!sched)
 414                 return NULL;
 415
 416         if (sched->root) {
 417                 type = isl_schedule_tree_get_type(sched->root);
 418                 if (type != isl_schedule_node_domain)
 419                         isl_die(isl_schedule_get_ctx(sched), isl_error_internal,
 420                                 "root node not a domain node", return NULL);
 421
 422                 node = isl_schedule_get_root(sched);
 423                 node = isl_schedule_node_child(node, 0);
 424                 umap = isl_schedule_node_get_subtree_schedule_union_map(node);
 425                 isl_schedule_node_free(node);
 426
 427                 return umap;
 428         }
 429
 430         umap = isl_band_list_get_suffix_schedule(sched->band_forest);
 431         return pad_schedule_map(umap);
 432 }
 433
 434 static __isl_give isl_band_list *construct_band_list(
 435         __isl_take isl_schedule_node *node, __isl_take isl_union_set *domain,
 436         __isl_keep isl_band *parent);
 437
 438 /* Construct an isl_band structure from the given schedule tree node,
 439  * which may be either a band node or a leaf node.
 440  * In the latter case, construct a zero-dimensional band.
 441  * "domain" is the universe set of the domain elements that reach "node".
 442  * "parent" is the parent isl_band of the isl_band constructed
 443  * by this function.
 444  *
 445  * In case of a band node, we copy the properties (except tilability,
 446  * which is implicit in an isl_band) to the isl_band.
 447  * We assume that the band node is not zero-dimensional.
 448  * If the child of the band node is not a leaf node,
 449  * then we extract the children of the isl_band from this child.
 450  */
 451 static __isl_give isl_band *construct_band(__isl_take isl_schedule_node *node,
 452         __isl_take isl_union_set *domain, __isl_keep isl_band *parent)
 453 {
 454         int i;
 455         isl_ctx *ctx;
 456         isl_band *band = NULL;
 457         isl_multi_union_pw_aff *mupa;
 458
 459         if (!node || !domain)
 460                 goto error;
 461
 462         ctx = isl_schedule_node_get_ctx(node);
 463         band = isl_band_alloc(ctx);
 464         if (!band)
 465                 goto error;
 466
 467         band->schedule = node->schedule;
 468         band->parent = parent;
 469
 470         if (isl_schedule_node_get_type(node) == isl_schedule_node_leaf) {
 471                 band->n = 0;
 472                 band->pma = isl_union_pw_multi_aff_from_domain(domain);
 473                 isl_schedule_node_free(node);
 474                 return band;
 475         }
 476
 477         band->n = isl_schedule_node_band_n_member(node);
 478         if (band->n == 0)
 479                 isl_die(ctx, isl_error_unsupported,
 480                         "zero-dimensional band nodes not supported",
 481                         goto error);
 482         band->coincident = isl_alloc_array(ctx, int, band->n);
 483         if (band->n && !band->coincident)
 484                 goto error;
 485         for (i = 0; i < band->n; ++i)
 486                 band->coincident[i] =
 487                         isl_schedule_node_band_member_get_coincident(node, i);
 488         mupa = isl_schedule_node_band_get_partial_schedule(node);
 489         band->pma = isl_union_pw_multi_aff_from_multi_union_pw_aff(mupa);
 490         if (!band->pma)
 491                 goto error;
 492
 493         node = isl_schedule_node_child(node, 0);
 494         if (isl_schedule_node_get_type(node) == isl_schedule_node_leaf) {
 495                 isl_schedule_node_free(node);
 496                 isl_union_set_free(domain);
 497                 return band;
 498         }
 499
 500         band->children = construct_band_list(node, domain, band);
 501         if (!band->children)
 502                 return isl_band_free(band);
 503
 504         return band;
 505 error:
 506         isl_union_set_free(domain);
 507         isl_schedule_node_free(node);
 508         isl_band_free(band);
 509         return NULL;
 510 }
 511
 512 /* Construct a list of isl_band structures from the children of "node".
 513  * "node" itself is a sequence or set node, so that each of the child nodes
 514  * is a filter node and the list returned by node_construct_band_list
 515  * consists of a single element.
 516  * "domain" is the universe set of the domain elements that reach "node".
 517  * "parent" is the parent isl_band of the isl_band structures constructed
 518  * by this function.
 519  */
 520 static __isl_give isl_band_list *construct_band_list_from_children(
 521         __isl_take isl_schedule_node *node, __isl_take isl_union_set *domain,
 522         __isl_keep isl_band *parent)
 523 {
 524         int i, n;
 525         isl_ctx *ctx;
 526         isl_band_list *list;
 527
 528         n = isl_schedule_node_n_children(node);
 529
 530         ctx = isl_schedule_node_get_ctx(node);
 531         list = isl_band_list_alloc(ctx, 0);
 532         for (i = 0; i < n; ++i) {
 533                 isl_schedule_node *child;
 534                 isl_band_list *list_i;
 535
 536                 child = isl_schedule_node_get_child(node, i);
 537                 list_i = construct_band_list(child, isl_union_set_copy(domain),
 538                                                 parent);
 539                 list = isl_band_list_concat(list, list_i);
 540         }
 541
 542         isl_union_set_free(domain);
 543         isl_schedule_node_free(node);
 544
 545         return list;
 546 }
 547
 548 /* Construct an isl_band structure from the given sequence node
 549  * (or set node that is treated as a sequence node).
 550  * A single-dimensional band is created with as schedule for each of
 551  * filters of the children, the corresponding child position.
 552  * "domain" is the universe set of the domain elements that reach "node".
 553  * "parent" is the parent isl_band of the isl_band constructed
 554  * by this function.
 555  */
 556 static __isl_give isl_band_list *construct_band_list_sequence(
 557         __isl_take isl_schedule_node *node, __isl_take isl_union_set *domain,
 558         __isl_keep isl_band *parent)
 559 {
 560         int i, n;
 561         isl_ctx *ctx;
 562         isl_band *band = NULL;
 563         isl_space *space;
 564         isl_union_pw_multi_aff *upma;
 565
 566         if (!node || !domain)
 567                 goto error;
 568
 569         ctx = isl_schedule_node_get_ctx(node);
 570         band = isl_band_alloc(ctx);
 571         if (!band)
 572                 goto error;
 573
 574         band->schedule = node->schedule;
 575         band->parent = parent;
 576         band->n = 1;
 577         band->coincident = isl_calloc_array(ctx, int, band->n);
 578         if (!band->coincident)
 579                 goto error;
 580
 581         n = isl_schedule_node_n_children(node);
 582         space = isl_union_set_get_space(domain);
 583         upma = isl_union_pw_multi_aff_empty(isl_space_copy(space));
 584
 585         space = isl_space_set_from_params(space);
 586         space = isl_space_add_dims(space, isl_dim_set, 1);
 587
 588         for (i = 0; i < n; ++i) {
 589                 isl_schedule_node *child;
 590                 isl_union_set *filter;
 591                 isl_val *v;
 592                 isl_val_list *vl;
 593                 isl_multi_val *mv;
 594                 isl_union_pw_multi_aff *upma_i;
 595
 596                 child = isl_schedule_node_get_child(node, i);
 597                 filter = isl_schedule_node_filter_get_filter(child);
 598                 isl_schedule_node_free(child);
 599                 filter = isl_union_set_intersect(filter,
 600                                                 isl_union_set_copy(domain));
 601                 v = isl_val_int_from_si(ctx, i);
 602                 vl = isl_val_list_from_val(v);
 603                 mv = isl_multi_val_from_val_list(isl_space_copy(space), vl);
 604                 upma_i = isl_union_pw_multi_aff_multi_val_on_domain(filter, mv);
 605                 upma = isl_union_pw_multi_aff_union_add(upma, upma_i);
 606         }
 607
 608         isl_space_free(space);
 609
 610         band->pma = upma;
 611         if (!band->pma)
 612                 goto error;
 613
 614         band->children = construct_band_list_from_children(node, domain, band);
 615         if (!band->children)
 616                 band = isl_band_free(band);
 617         return isl_band_list_from_band(band);
 618 error:
 619         isl_union_set_free(domain);
 620         isl_schedule_node_free(node);
 621         isl_band_free(band);
 622         return NULL;
 623 }
 624
 625 /* Construct a list of isl_band structures from "node" depending
 626  * on the type of "node".
 627  * "domain" is the universe set of the domain elements that reach "node".
 628  * "parent" is the parent isl_band of the isl_band structures constructed
 629  * by this function.
 630  *
 631  * If schedule_separate_components is set then set nodes are treated
 632  * as sequence nodes.  Otherwise, we directly extract an (implicitly
 633  * parallel) list of isl_band structures.
 634  *
 635  * If "node" is a filter, then "domain" is updated by the filter.
 636  */
 637 static __isl_give isl_band_list *construct_band_list(
 638         __isl_take isl_schedule_node *node, __isl_take isl_union_set *domain,
 639         __isl_keep isl_band *parent)
 640 {
 641         enum isl_schedule_node_type type;
 642         isl_ctx *ctx;
 643         isl_band *band;
 644         isl_band_list *list;
 645         isl_union_set *filter;
 646
 647         if (!node || !domain)
 648                 goto error;
 649
 650         type = isl_schedule_node_get_type(node);
 651         switch (type) {
 652         case isl_schedule_node_error:
 653                 goto error;
 654         case isl_schedule_node_domain:
 655                 isl_die(isl_schedule_node_get_ctx(node), isl_error_invalid,
 656                         "internal domain nodes not allowed", goto error);
 657         case isl_schedule_node_filter:
 658                 filter = isl_schedule_node_filter_get_filter(node);
 659                 domain = isl_union_set_intersect(domain, filter);
 660                 node = isl_schedule_node_child(node, 0);
 661                 return construct_band_list(node, domain, parent);
 662         case isl_schedule_node_set:
 663                 ctx = isl_schedule_node_get_ctx(node);
 664                 if (isl_options_get_schedule_separate_components(ctx))
 665                         return construct_band_list_sequence(node, domain,
 666                                                             parent);
 667                 else
 668                         return construct_band_list_from_children(node, domain,
 669                                                             parent);
 670         case isl_schedule_node_sequence:
 671                 return construct_band_list_sequence(node, domain, parent);
 672         case isl_schedule_node_leaf:
 673         case isl_schedule_node_band:
 674                 band = construct_band(node, domain, parent);
 675                 list = isl_band_list_from_band(band);
 676                 break;
 677         }
 678
 679         return list;
 680 error:
 681         isl_union_set_free(domain);
 682         isl_schedule_node_free(node);
 683         return NULL;
 684 }
 685
 686 /* Return the roots of a band forest representation of the schedule.
 687  * The band forest is constructed from the schedule tree,
 688  * but once such a band forest is
 689  * constructed, we forget about the original schedule tree since
 690  * the user may modify the schedule through the band forest.
 691  */
 692 __isl_give isl_band_list *isl_schedule_get_band_forest(
 693         __isl_keep isl_schedule *schedule)
 694 {
 695         isl_schedule_node *node;
 696         isl_union_set *domain;
 697
 698         if (!schedule)
 699                 return NULL;
 700         if (schedule->root) {
 701                 node = isl_schedule_get_root(schedule);
 702                 domain = isl_schedule_node_domain_get_domain(node);
 703                 domain = isl_union_set_universe(domain);
 704                 node = isl_schedule_node_child(node, 0);
 705
 706                 schedule->band_forest = construct_band_list(node, domain, NULL);
 707                 schedule->root = isl_schedule_tree_free(schedule->root);
 708         }
 709         return isl_band_list_dup(schedule->band_forest);
 710 }
 711
 712 /* Call "fn" on each band in the schedule in depth-first post-order.
 713  */
 714 int isl_schedule_foreach_band(__isl_keep isl_schedule *sched,
 715         int (*fn)(__isl_keep isl_band *band, void *user), void *user)
 716 {
 717         int r;
 718         isl_band_list *forest;
 719
 720         if (!sched)
 721                 return -1;
 722
 723         forest = isl_schedule_get_band_forest(sched);
 724         r = isl_band_list_foreach_band(forest, fn, user);
 725         isl_band_list_free(forest);
 726
 727         return r;
 728 }
 729
 730 static __isl_give isl_printer *print_band_list(__isl_take isl_printer *p,
 731         __isl_keep isl_band_list *list);
 732
 733 static __isl_give isl_printer *print_band(__isl_take isl_printer *p,
 734         __isl_keep isl_band *band)
 735 {
 736         isl_band_list *children;
 737
 738         p = isl_printer_start_line(p);
 739         p = isl_printer_print_union_pw_multi_aff(p, band->pma);
 740         p = isl_printer_end_line(p);
 741
 742         if (!isl_band_has_children(band))
 743                 return p;
 744
 745         children = isl_band_get_children(band);
 746
 747         p = isl_printer_indent(p, 4);
 748         p = print_band_list(p, children);
 749         p = isl_printer_indent(p, -4);
 750
 751         isl_band_list_free(children);
 752
 753         return p;
 754 }
 755
 756 static __isl_give isl_printer *print_band_list(__isl_take isl_printer *p,
 757         __isl_keep isl_band_list *list)
 758 {
 759         int i, n;
 760
 761         n = isl_band_list_n_band(list);
 762         for (i = 0; i < n; ++i) {
 763                 isl_band *band;
 764                 band = isl_band_list_get_band(list, i);
 765                 p = print_band(p, band);
 766                 isl_band_free(band);
 767         }
 768
 769         return p;
 770 }
 771
 772 /* Insert a band node with partial schedule "partial" between the domain
 773  * root node of "schedule" and its single child.
 774  * Return a pointer to the updated schedule.
 775  */
 776 __isl_give isl_schedule *isl_schedule_insert_partial_schedule(
 777         __isl_take isl_schedule *schedule,
 778         __isl_take isl_multi_union_pw_aff *partial)
 779 {
 780         isl_schedule_node *node;
 781
 782         node = isl_schedule_get_root(schedule);
 783         isl_schedule_free(schedule);
 784         if (!node)
 785                 goto error;
 786         if (isl_schedule_node_get_type(node) != isl_schedule_node_domain)
 787                 isl_die(isl_schedule_node_get_ctx(node), isl_error_internal,
 788                         "root node not a domain node", goto error);
 789
 790         node = isl_schedule_node_child(node, 0);
 791         node = isl_schedule_node_insert_partial_schedule(node, partial);
 792
 793         schedule = isl_schedule_node_get_schedule(node);
 794         isl_schedule_node_free(node);
 795
 796         return schedule;
 797 error:
 798         isl_schedule_node_free(node);
 799         isl_multi_union_pw_aff_free(partial);
 800         return NULL;
 801 }
 802
 803 /* Return a tree with as top-level node a filter corresponding to "filter" and
 804  * as child, the (single) child of "tree".
 805  * However, if this single child is of type "type", then the filter is inserted
 806  * in the children of this single child instead.
 807  */
 808 static __isl_give isl_schedule_tree *insert_filter_in_child_of_type(
 809         __isl_take isl_schedule_tree *tree, __isl_take isl_union_set *filter,
 810         enum isl_schedule_node_type type)
 811 {
 812         if (!isl_schedule_tree_has_children(tree)) {
 813                 isl_schedule_tree_free(tree);
 814                 return isl_schedule_tree_from_filter(filter);
 815         } else {
 816                 tree = isl_schedule_tree_child(tree, 0);
 817         }
 818
 819         if (isl_schedule_tree_get_type(tree) == type)
 820                 tree = isl_schedule_tree_children_insert_filter(tree, filter);
 821         else
 822                 tree = isl_schedule_tree_insert_filter(tree, filter);
 823
 824         return tree;
 825 }
 826
 827 /* Construct a schedule that combines the schedules "schedule1" and "schedule2"
 828  * with a top-level node (underneath the domain node) of type "type",
 829  * either isl_schedule_node_sequence or isl_schedule_node_set.
 830  * The domains of the two schedules are assumed to be disjoint.
 831  *
 832  * The new schedule has as domain the union of the domains of the two
 833  * schedules.  The child of the domain node is a node of type "type"
 834  * with two filters corresponding to the domains of the input schedules.
 835  * If one (or both) of the top-level nodes of the two schedules is itself
 836  * of type "type", then the filter is pushed into the children of that
 837  * node and the sequence of set is flattened.
 838  */
 839 __isl_give isl_schedule *isl_schedule_pair(enum isl_schedule_node_type type,
 840         __isl_take isl_schedule *schedule1, __isl_take isl_schedule *schedule2)
 841 {
 842         int disjoint;
 843         isl_ctx *ctx;
 844         enum isl_schedule_node_type root_type;
 845         isl_schedule_tree *tree1, *tree2;
 846         isl_union_set *filter1, *filter2, *domain;
 847
 848         if (!schedule1 || !schedule2)
 849                 goto error;
 850
 851         root_type = isl_schedule_tree_get_type(schedule1->root);
 852         if (root_type != isl_schedule_node_domain)
 853                 isl_die(isl_schedule_get_ctx(schedule1), isl_error_internal,
 854                         "root node not a domain node", goto error);
 855         root_type = isl_schedule_tree_get_type(schedule2->root);
 856         if (root_type != isl_schedule_node_domain)
 857                 isl_die(isl_schedule_get_ctx(schedule1), isl_error_internal,
 858                         "root node not a domain node", goto error);
 859
 860         ctx = isl_schedule_get_ctx(schedule1);
 861         tree1 = isl_schedule_tree_copy(schedule1->root);
 862         filter1 = isl_schedule_tree_domain_get_domain(tree1);
 863         tree2 = isl_schedule_tree_copy(schedule2->root);
 864         filter2 = isl_schedule_tree_domain_get_domain(tree2);
 865
 866         isl_schedule_free(schedule1);
 867         isl_schedule_free(schedule2);
 868
 869         disjoint = isl_union_set_is_disjoint(filter1, filter2);
 870         if (disjoint < 0)
 871                 filter1 = isl_union_set_free(filter1);
 872         if (!disjoint)
 873                 isl_die(ctx, isl_error_invalid,
 874                         "schedule domains not disjoint",
 875                         filter1 = isl_union_set_free(filter1));
 876
 877         domain = isl_union_set_union(isl_union_set_copy(filter1),
 878                                     isl_union_set_copy(filter2));
 879         filter1 = isl_union_set_gist(filter1, isl_union_set_copy(domain));
 880         filter2 = isl_union_set_gist(filter2, isl_union_set_copy(domain));
 881
 882         tree1 = insert_filter_in_child_of_type(tree1, filter1, type);
 883         tree2 = insert_filter_in_child_of_type(tree2, filter2, type);
 884
 885         tree1 = isl_schedule_tree_from_pair(type, tree1, tree2);
 886         tree1 = isl_schedule_tree_insert_domain(tree1, domain);
 887
 888         return isl_schedule_from_schedule_tree(ctx, tree1);
 889 error:
 890         isl_schedule_free(schedule1);
 891         isl_schedule_free(schedule2);
 892         return NULL;
 893 }
 894
 895 /* Construct a schedule that combines the schedules "schedule1" and "schedule2"
 896  * through a sequence node.
 897  * The domains of the input schedules are assumed to be disjoint.
 898  */
 899 __isl_give isl_schedule *isl_schedule_sequence(
 900         __isl_take isl_schedule *schedule1, __isl_take isl_schedule *schedule2)
 901 {
 902         return isl_schedule_pair(isl_schedule_node_sequence,
 903                                 schedule1, schedule2);
 904 }
 905
 906 /* Construct a schedule that combines the schedules "schedule1" and "schedule2"
 907  * through a set node.
 908  * The domains of the input schedules are assumed to be disjoint.
 909  */
 910 __isl_give isl_schedule *isl_schedule_set(
 911         __isl_take isl_schedule *schedule1, __isl_take isl_schedule *schedule2)
 912 {
 913         return isl_schedule_pair(isl_schedule_node_set, schedule1, schedule2);
 914 }
 915
 916 /* Print "schedule" to "p".
 917  *
 918  * If "schedule" was created from a schedule tree, then we print
 919  * the schedule tree representation.  Otherwise, we print
 920  * the band forest representation.
 921  */
 922 __isl_give isl_printer *isl_printer_print_schedule(__isl_take isl_printer *p,
 923         __isl_keep isl_schedule *schedule)
 924 {
 925         isl_band_list *forest;
 926
 927         if (!schedule)
 928                 return isl_printer_free(p);
 929
 930         if (schedule->root)
 931                 return isl_printer_print_schedule_tree(p, schedule->root);
 932
 933         forest = isl_schedule_get_band_forest(schedule);
 934
 935         p = print_band_list(p, forest);
 936
 937         isl_band_list_free(forest);
 938
 939         return p;
 940 }
 941
 942 void isl_schedule_dump(__isl_keep isl_schedule *schedule)
 943 {
 944         isl_printer *printer;
 945
 946         if (!schedule)
 947                 return;
 948
 949         printer = isl_printer_to_file(isl_schedule_get_ctx(schedule), stderr);
 950         printer = isl_printer_set_yaml_style(printer, ISL_YAML_STYLE_BLOCK);
 951         printer = isl_printer_print_schedule(printer, schedule);
 952
 953         isl_printer_free(printer);
 954 }