isl_schedule_constraints_compute_schedule: optionally avoid loop coalescing
[isl.git] / isl_ast_codegen.c
blobccb11bb536127eb81a9fa7de9556b01930957ce0
1 /*
2 * Copyright 2012-2014 Ecole Normale Superieure
3 * Copyright 2014 INRIA Rocquencourt
5 * Use of this software is governed by the MIT license
7 * Written by Sven Verdoolaege,
8 * Ecole Normale Superieure, 45 rue d’Ulm, 75230 Paris, France
9 * and Inria Paris - Rocquencourt, Domaine de Voluceau - Rocquencourt,
10 * B.P. 105 - 78153 Le Chesnay, France
13 #include <limits.h>
14 #include <isl/aff.h>
15 #include <isl/constraint.h>
16 #include <isl/set.h>
17 #include <isl/ilp.h>
18 #include <isl/union_set.h>
19 #include <isl/union_map.h>
20 #include <isl/schedule_node.h>
21 #include <isl_sort.h>
22 #include <isl_tarjan.h>
23 #include <isl_ast_private.h>
24 #include <isl_ast_build_expr.h>
25 #include <isl_ast_build_private.h>
26 #include <isl_ast_graft_private.h>
28 /* Data used in generate_domain.
30 * "build" is the input build.
31 * "list" collects the results.
33 struct isl_generate_domain_data {
34 isl_ast_build *build;
36 isl_ast_graft_list *list;
39 static __isl_give isl_ast_graft_list *generate_next_level(
40 __isl_take isl_union_map *executed,
41 __isl_take isl_ast_build *build);
42 static __isl_give isl_ast_graft_list *generate_code(
43 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build,
44 int internal);
46 /* Generate an AST for a single domain based on
47 * the (non single valued) inverse schedule "executed".
49 * We extend the schedule with the iteration domain
50 * and continue generating through a call to generate_code.
52 * In particular, if executed has the form
54 * S -> D
56 * then we continue generating code on
58 * [S -> D] -> D
60 * The extended inverse schedule is clearly single valued
61 * ensuring that the nested generate_code will not reach this function,
62 * but will instead create calls to all elements of D that need
63 * to be executed from the current schedule domain.
65 static isl_stat generate_non_single_valued(__isl_take isl_map *executed,
66 struct isl_generate_domain_data *data)
68 isl_map *identity;
69 isl_ast_build *build;
70 isl_ast_graft_list *list;
72 build = isl_ast_build_copy(data->build);
74 identity = isl_set_identity(isl_map_range(isl_map_copy(executed)));
75 executed = isl_map_domain_product(executed, identity);
76 build = isl_ast_build_set_single_valued(build, 1);
78 list = generate_code(isl_union_map_from_map(executed), build, 1);
80 data->list = isl_ast_graft_list_concat(data->list, list);
82 return isl_stat_ok;
85 /* Call the at_each_domain callback, if requested by the user,
86 * after recording the current inverse schedule in the build.
88 static __isl_give isl_ast_graft *at_each_domain(__isl_take isl_ast_graft *graft,
89 __isl_keep isl_map *executed, __isl_keep isl_ast_build *build)
91 if (!graft || !build)
92 return isl_ast_graft_free(graft);
93 if (!build->at_each_domain)
94 return graft;
96 build = isl_ast_build_copy(build);
97 build = isl_ast_build_set_executed(build,
98 isl_union_map_from_map(isl_map_copy(executed)));
99 if (!build)
100 return isl_ast_graft_free(graft);
102 graft->node = build->at_each_domain(graft->node,
103 build, build->at_each_domain_user);
104 isl_ast_build_free(build);
106 if (!graft->node)
107 graft = isl_ast_graft_free(graft);
109 return graft;
112 /* Generate a call expression for the single executed
113 * domain element "map" and put a guard around it based its (simplified)
114 * domain. "executed" is the original inverse schedule from which "map"
115 * has been derived. In particular, "map" is either identical to "executed"
116 * or it is the result of gisting "executed" with respect to the build domain.
117 * "executed" is only used if there is an at_each_domain callback.
119 * At this stage, any pending constraints in the build can no longer
120 * be simplified with respect to any enforced constraints since
121 * the call node does not have any enforced constraints.
122 * Since all pending constraints not covered by any enforced constraints
123 * will be added as a guard to the graft in create_node_scaled,
124 * even in the eliminated case, the pending constraints
125 * can be considered to have been generated by outer constructs.
127 * If the user has set an at_each_domain callback, it is called
128 * on the constructed call expression node.
130 static isl_stat add_domain(__isl_take isl_map *executed,
131 __isl_take isl_map *map, struct isl_generate_domain_data *data)
133 isl_ast_build *build;
134 isl_ast_graft *graft;
135 isl_ast_graft_list *list;
136 isl_set *guard, *pending;
138 build = isl_ast_build_copy(data->build);
139 pending = isl_ast_build_get_pending(build);
140 build = isl_ast_build_replace_pending_by_guard(build, pending);
142 guard = isl_map_domain(isl_map_copy(map));
143 guard = isl_set_compute_divs(guard);
144 guard = isl_set_coalesce(guard);
145 guard = isl_set_gist(guard, isl_ast_build_get_generated(build));
146 guard = isl_ast_build_specialize(build, guard);
148 graft = isl_ast_graft_alloc_domain(map, build);
149 graft = at_each_domain(graft, executed, build);
150 isl_ast_build_free(build);
151 isl_map_free(executed);
152 graft = isl_ast_graft_add_guard(graft, guard, data->build);
154 list = isl_ast_graft_list_from_ast_graft(graft);
155 data->list = isl_ast_graft_list_concat(data->list, list);
157 return isl_stat_ok;
160 /* Generate an AST for a single domain based on
161 * the inverse schedule "executed" and add it to data->list.
163 * If there is more than one domain element associated to the current
164 * schedule "time", then we need to continue the generation process
165 * in generate_non_single_valued.
166 * Note that the inverse schedule being single-valued may depend
167 * on constraints that are only available in the original context
168 * domain specified by the user. We therefore first introduce
169 * some of the constraints of data->build->domain. In particular,
170 * we intersect with a single-disjunct approximation of this set.
171 * We perform this approximation to avoid further splitting up
172 * the executed relation, possibly introducing a disjunctive guard
173 * on the statement.
175 * On the other hand, we only perform the test after having taken the gist
176 * of the domain as the resulting map is the one from which the call
177 * expression is constructed. Using this map to construct the call
178 * expression usually yields simpler results in cases where the original
179 * map is not obviously single-valued.
180 * If the original map is obviously single-valued, then the gist
181 * operation is skipped.
183 * Because we perform the single-valuedness test on the gisted map,
184 * we may in rare cases fail to recognize that the inverse schedule
185 * is single-valued. This becomes problematic if this happens
186 * from the recursive call through generate_non_single_valued
187 * as we would then end up in an infinite recursion.
188 * We therefore check if we are inside a call to generate_non_single_valued
189 * and revert to the ungisted map if the gisted map turns out not to be
190 * single-valued.
192 * Otherwise, call add_domain to generate a call expression (with guard) and
193 * to call the at_each_domain callback, if any.
195 static isl_stat generate_domain(__isl_take isl_map *executed, void *user)
197 struct isl_generate_domain_data *data = user;
198 isl_set *domain;
199 isl_map *map = NULL;
200 int empty, sv;
202 domain = isl_ast_build_get_domain(data->build);
203 domain = isl_set_from_basic_set(isl_set_simple_hull(domain));
204 executed = isl_map_intersect_domain(executed, domain);
205 empty = isl_map_is_empty(executed);
206 if (empty < 0)
207 goto error;
208 if (empty) {
209 isl_map_free(executed);
210 return isl_stat_ok;
213 sv = isl_map_plain_is_single_valued(executed);
214 if (sv < 0)
215 goto error;
216 if (sv)
217 return add_domain(executed, isl_map_copy(executed), data);
219 executed = isl_map_coalesce(executed);
220 map = isl_map_copy(executed);
221 map = isl_ast_build_compute_gist_map_domain(data->build, map);
222 sv = isl_map_is_single_valued(map);
223 if (sv < 0)
224 goto error;
225 if (!sv) {
226 isl_map_free(map);
227 if (data->build->single_valued)
228 map = isl_map_copy(executed);
229 else
230 return generate_non_single_valued(executed, data);
233 return add_domain(executed, map, data);
234 error:
235 isl_map_free(map);
236 isl_map_free(executed);
237 return isl_stat_error;
240 /* Call build->create_leaf to a create "leaf" node in the AST,
241 * encapsulate the result in an isl_ast_graft and return the result
242 * as a 1-element list.
244 * Note that the node returned by the user may be an entire tree.
246 * Since the node itself cannot enforce any constraints, we turn
247 * all pending constraints into guards and add them to the resulting
248 * graft to ensure that they will be generated.
250 * Before we pass control to the user, we first clear some information
251 * from the build that is (presumbably) only meaningful
252 * for the current code generation.
253 * This includes the create_leaf callback itself, so we make a copy
254 * of the build first.
256 static __isl_give isl_ast_graft_list *call_create_leaf(
257 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build)
259 isl_set *guard;
260 isl_ast_node *node;
261 isl_ast_graft *graft;
262 isl_ast_build *user_build;
264 guard = isl_ast_build_get_pending(build);
265 user_build = isl_ast_build_copy(build);
266 user_build = isl_ast_build_replace_pending_by_guard(user_build,
267 isl_set_copy(guard));
268 user_build = isl_ast_build_set_executed(user_build, executed);
269 user_build = isl_ast_build_clear_local_info(user_build);
270 if (!user_build)
271 node = NULL;
272 else
273 node = build->create_leaf(user_build, build->create_leaf_user);
274 graft = isl_ast_graft_alloc(node, build);
275 graft = isl_ast_graft_add_guard(graft, guard, build);
276 isl_ast_build_free(build);
277 return isl_ast_graft_list_from_ast_graft(graft);
280 static __isl_give isl_ast_graft_list *build_ast_from_child(
281 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
282 __isl_take isl_union_map *executed);
284 /* Generate an AST after having handled the complete schedule
285 * of this call to the code generator or the complete band
286 * if we are generating an AST from a schedule tree.
288 * If we are inside a band node, then move on to the child of the band.
290 * If the user has specified a create_leaf callback, control
291 * is passed to the user in call_create_leaf.
293 * Otherwise, we generate one or more calls for each individual
294 * domain in generate_domain.
296 static __isl_give isl_ast_graft_list *generate_inner_level(
297 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build)
299 isl_ctx *ctx;
300 struct isl_generate_domain_data data = { build };
302 if (!build || !executed)
303 goto error;
305 if (isl_ast_build_has_schedule_node(build)) {
306 isl_schedule_node *node;
307 node = isl_ast_build_get_schedule_node(build);
308 build = isl_ast_build_reset_schedule_node(build);
309 return build_ast_from_child(build, node, executed);
312 if (build->create_leaf)
313 return call_create_leaf(executed, build);
315 ctx = isl_union_map_get_ctx(executed);
316 data.list = isl_ast_graft_list_alloc(ctx, 0);
317 if (isl_union_map_foreach_map(executed, &generate_domain, &data) < 0)
318 data.list = isl_ast_graft_list_free(data.list);
320 if (0)
321 error: data.list = NULL;
322 isl_ast_build_free(build);
323 isl_union_map_free(executed);
324 return data.list;
327 /* Call the before_each_for callback, if requested by the user.
329 static __isl_give isl_ast_node *before_each_for(__isl_take isl_ast_node *node,
330 __isl_keep isl_ast_build *build)
332 isl_id *id;
334 if (!node || !build)
335 return isl_ast_node_free(node);
336 if (!build->before_each_for)
337 return node;
338 id = build->before_each_for(build, build->before_each_for_user);
339 node = isl_ast_node_set_annotation(node, id);
340 return node;
343 /* Call the after_each_for callback, if requested by the user.
345 static __isl_give isl_ast_graft *after_each_for(__isl_take isl_ast_graft *graft,
346 __isl_keep isl_ast_build *build)
348 if (!graft || !build)
349 return isl_ast_graft_free(graft);
350 if (!build->after_each_for)
351 return graft;
352 graft->node = build->after_each_for(graft->node, build,
353 build->after_each_for_user);
354 if (!graft->node)
355 return isl_ast_graft_free(graft);
356 return graft;
359 /* Plug in all the know values of the current and outer dimensions
360 * in the domain of "executed". In principle, we only need to plug
361 * in the known value of the current dimension since the values of
362 * outer dimensions have been plugged in already.
363 * However, it turns out to be easier to just plug in all known values.
365 static __isl_give isl_union_map *plug_in_values(
366 __isl_take isl_union_map *executed, __isl_keep isl_ast_build *build)
368 return isl_ast_build_substitute_values_union_map_domain(build,
369 executed);
372 /* Check if the constraint "c" is a lower bound on dimension "pos",
373 * an upper bound, or independent of dimension "pos".
375 static int constraint_type(isl_constraint *c, int pos)
377 if (isl_constraint_is_lower_bound(c, isl_dim_set, pos))
378 return 1;
379 if (isl_constraint_is_upper_bound(c, isl_dim_set, pos))
380 return 2;
381 return 0;
384 /* Compare the types of the constraints "a" and "b",
385 * resulting in constraints that are independent of "depth"
386 * to be sorted before the lower bounds on "depth", which in
387 * turn are sorted before the upper bounds on "depth".
389 static int cmp_constraint(__isl_keep isl_constraint *a,
390 __isl_keep isl_constraint *b, void *user)
392 int *depth = user;
393 int t1 = constraint_type(a, *depth);
394 int t2 = constraint_type(b, *depth);
396 return t1 - t2;
399 /* Extract a lower bound on dimension "pos" from constraint "c".
401 * If the constraint is of the form
403 * a x + f(...) >= 0
405 * then we essentially return
407 * l = ceil(-f(...)/a)
409 * However, if the current dimension is strided, then we need to make
410 * sure that the lower bound we construct is of the form
412 * f + s a
414 * with f the offset and s the stride.
415 * We therefore compute
417 * f + s * ceil((l - f)/s)
419 static __isl_give isl_aff *lower_bound(__isl_keep isl_constraint *c,
420 int pos, __isl_keep isl_ast_build *build)
422 isl_aff *aff;
424 aff = isl_constraint_get_bound(c, isl_dim_set, pos);
425 aff = isl_aff_ceil(aff);
427 if (isl_ast_build_has_stride(build, pos)) {
428 isl_aff *offset;
429 isl_val *stride;
431 offset = isl_ast_build_get_offset(build, pos);
432 stride = isl_ast_build_get_stride(build, pos);
434 aff = isl_aff_sub(aff, isl_aff_copy(offset));
435 aff = isl_aff_scale_down_val(aff, isl_val_copy(stride));
436 aff = isl_aff_ceil(aff);
437 aff = isl_aff_scale_val(aff, stride);
438 aff = isl_aff_add(aff, offset);
441 aff = isl_ast_build_compute_gist_aff(build, aff);
443 return aff;
446 /* Return the exact lower bound (or upper bound if "upper" is set)
447 * of "domain" as a piecewise affine expression.
449 * If we are computing a lower bound (of a strided dimension), then
450 * we need to make sure it is of the form
452 * f + s a
454 * where f is the offset and s is the stride.
455 * We therefore need to include the stride constraint before computing
456 * the minimum.
458 static __isl_give isl_pw_aff *exact_bound(__isl_keep isl_set *domain,
459 __isl_keep isl_ast_build *build, int upper)
461 isl_set *stride;
462 isl_map *it_map;
463 isl_pw_aff *pa;
464 isl_pw_multi_aff *pma;
466 domain = isl_set_copy(domain);
467 if (!upper) {
468 stride = isl_ast_build_get_stride_constraint(build);
469 domain = isl_set_intersect(domain, stride);
471 it_map = isl_ast_build_map_to_iterator(build, domain);
472 if (upper)
473 pma = isl_map_lexmax_pw_multi_aff(it_map);
474 else
475 pma = isl_map_lexmin_pw_multi_aff(it_map);
476 pa = isl_pw_multi_aff_get_pw_aff(pma, 0);
477 isl_pw_multi_aff_free(pma);
478 pa = isl_ast_build_compute_gist_pw_aff(build, pa);
479 pa = isl_pw_aff_coalesce(pa);
481 return pa;
484 /* Callback for sorting the isl_pw_aff_list passed to reduce_list and
485 * remove_redundant_lower_bounds.
487 static int reduce_list_cmp(__isl_keep isl_pw_aff *a, __isl_keep isl_pw_aff *b,
488 void *user)
490 return isl_pw_aff_plain_cmp(a, b);
493 /* Given a list of lower bounds "list", remove those that are redundant
494 * with respect to the other bounds in "list" and the domain of "build".
496 * We first sort the bounds in the same way as they would be sorted
497 * by set_for_node_expressions so that we can try and remove the last
498 * bounds first.
500 * For a lower bound to be effective, there needs to be at least
501 * one domain element for which it is larger than all other lower bounds.
502 * For each lower bound we therefore intersect the domain with
503 * the conditions that it is larger than all other bounds and
504 * check whether the result is empty. If so, the bound can be removed.
506 static __isl_give isl_pw_aff_list *remove_redundant_lower_bounds(
507 __isl_take isl_pw_aff_list *list, __isl_keep isl_ast_build *build)
509 int i, j, n;
510 isl_set *domain;
512 list = isl_pw_aff_list_sort(list, &reduce_list_cmp, NULL);
513 if (!list)
514 return NULL;
516 n = isl_pw_aff_list_n_pw_aff(list);
517 if (n <= 1)
518 return list;
520 domain = isl_ast_build_get_domain(build);
522 for (i = n - 1; i >= 0; --i) {
523 isl_pw_aff *pa_i;
524 isl_set *domain_i;
525 int empty;
527 domain_i = isl_set_copy(domain);
528 pa_i = isl_pw_aff_list_get_pw_aff(list, i);
530 for (j = 0; j < n; ++j) {
531 isl_pw_aff *pa_j;
532 isl_set *better;
534 if (j == i)
535 continue;
537 pa_j = isl_pw_aff_list_get_pw_aff(list, j);
538 better = isl_pw_aff_gt_set(isl_pw_aff_copy(pa_i), pa_j);
539 domain_i = isl_set_intersect(domain_i, better);
542 empty = isl_set_is_empty(domain_i);
544 isl_set_free(domain_i);
545 isl_pw_aff_free(pa_i);
547 if (empty < 0)
548 goto error;
549 if (!empty)
550 continue;
551 list = isl_pw_aff_list_drop(list, i, 1);
552 n--;
555 isl_set_free(domain);
557 return list;
558 error:
559 isl_set_free(domain);
560 return isl_pw_aff_list_free(list);
563 /* Extract a lower bound on dimension "pos" from each constraint
564 * in "constraints" and return the list of lower bounds.
565 * If "constraints" has zero elements, then we extract a lower bound
566 * from "domain" instead.
568 * If the current dimension is strided, then the lower bound
569 * is adjusted by lower_bound to match the stride information.
570 * This modification may make one or more lower bounds redundant
571 * with respect to the other lower bounds. We therefore check
572 * for this condition and remove the redundant lower bounds.
574 static __isl_give isl_pw_aff_list *lower_bounds(
575 __isl_keep isl_constraint_list *constraints, int pos,
576 __isl_keep isl_set *domain, __isl_keep isl_ast_build *build)
578 isl_ctx *ctx;
579 isl_pw_aff_list *list;
580 int i, n;
582 if (!build)
583 return NULL;
585 n = isl_constraint_list_n_constraint(constraints);
586 if (n == 0) {
587 isl_pw_aff *pa;
588 pa = exact_bound(domain, build, 0);
589 return isl_pw_aff_list_from_pw_aff(pa);
592 ctx = isl_ast_build_get_ctx(build);
593 list = isl_pw_aff_list_alloc(ctx,n);
595 for (i = 0; i < n; ++i) {
596 isl_aff *aff;
597 isl_constraint *c;
599 c = isl_constraint_list_get_constraint(constraints, i);
600 aff = lower_bound(c, pos, build);
601 isl_constraint_free(c);
602 list = isl_pw_aff_list_add(list, isl_pw_aff_from_aff(aff));
605 if (isl_ast_build_has_stride(build, pos))
606 list = remove_redundant_lower_bounds(list, build);
608 return list;
611 /* Extract an upper bound on dimension "pos" from each constraint
612 * in "constraints" and return the list of upper bounds.
613 * If "constraints" has zero elements, then we extract an upper bound
614 * from "domain" instead.
616 static __isl_give isl_pw_aff_list *upper_bounds(
617 __isl_keep isl_constraint_list *constraints, int pos,
618 __isl_keep isl_set *domain, __isl_keep isl_ast_build *build)
620 isl_ctx *ctx;
621 isl_pw_aff_list *list;
622 int i, n;
624 n = isl_constraint_list_n_constraint(constraints);
625 if (n == 0) {
626 isl_pw_aff *pa;
627 pa = exact_bound(domain, build, 1);
628 return isl_pw_aff_list_from_pw_aff(pa);
631 ctx = isl_ast_build_get_ctx(build);
632 list = isl_pw_aff_list_alloc(ctx,n);
634 for (i = 0; i < n; ++i) {
635 isl_aff *aff;
636 isl_constraint *c;
638 c = isl_constraint_list_get_constraint(constraints, i);
639 aff = isl_constraint_get_bound(c, isl_dim_set, pos);
640 isl_constraint_free(c);
641 aff = isl_aff_floor(aff);
642 list = isl_pw_aff_list_add(list, isl_pw_aff_from_aff(aff));
645 return list;
648 /* Return an isl_ast_expr that performs the reduction of type "type"
649 * on AST expressions corresponding to the elements in "list".
651 * The list is assumed to contain at least one element.
652 * If the list contains exactly one element, then the returned isl_ast_expr
653 * simply computes that affine expression.
654 * If the list contains more than one element, then we sort it
655 * using a fairly abitrary but hopefully reasonably stable order.
657 static __isl_give isl_ast_expr *reduce_list(enum isl_ast_op_type type,
658 __isl_keep isl_pw_aff_list *list, __isl_keep isl_ast_build *build)
660 int i, n;
661 isl_ctx *ctx;
662 isl_ast_expr *expr;
664 if (!list)
665 return NULL;
667 n = isl_pw_aff_list_n_pw_aff(list);
669 if (n == 1)
670 return isl_ast_build_expr_from_pw_aff_internal(build,
671 isl_pw_aff_list_get_pw_aff(list, 0));
673 ctx = isl_pw_aff_list_get_ctx(list);
674 expr = isl_ast_expr_alloc_op(ctx, type, n);
675 if (!expr)
676 return NULL;
678 list = isl_pw_aff_list_copy(list);
679 list = isl_pw_aff_list_sort(list, &reduce_list_cmp, NULL);
680 if (!list)
681 return isl_ast_expr_free(expr);
683 for (i = 0; i < n; ++i) {
684 isl_ast_expr *expr_i;
686 expr_i = isl_ast_build_expr_from_pw_aff_internal(build,
687 isl_pw_aff_list_get_pw_aff(list, i));
688 if (!expr_i)
689 goto error;
690 expr->u.op.args[i] = expr_i;
693 isl_pw_aff_list_free(list);
694 return expr;
695 error:
696 isl_pw_aff_list_free(list);
697 isl_ast_expr_free(expr);
698 return NULL;
701 /* Add guards implied by the "generated constraints",
702 * but not (necessarily) enforced by the generated AST to "guard".
703 * In particular, if there is any stride constraints,
704 * then add the guard implied by those constraints.
705 * If we have generated a degenerate loop, then add the guard
706 * implied by "bounds" on the outer dimensions, i.e., the guard
707 * that ensures that the single value actually exists.
708 * Since there may also be guards implied by a combination
709 * of these constraints, we first combine them before
710 * deriving the implied constraints.
712 static __isl_give isl_set *add_implied_guards(__isl_take isl_set *guard,
713 int degenerate, __isl_keep isl_basic_set *bounds,
714 __isl_keep isl_ast_build *build)
716 int depth, has_stride;
717 isl_space *space;
718 isl_set *dom, *set;
720 depth = isl_ast_build_get_depth(build);
721 has_stride = isl_ast_build_has_stride(build, depth);
722 if (!has_stride && !degenerate)
723 return guard;
725 space = isl_basic_set_get_space(bounds);
726 dom = isl_set_universe(space);
728 if (degenerate) {
729 bounds = isl_basic_set_copy(bounds);
730 bounds = isl_basic_set_drop_constraints_not_involving_dims(
731 bounds, isl_dim_set, depth, 1);
732 set = isl_set_from_basic_set(bounds);
733 dom = isl_set_intersect(dom, set);
736 if (has_stride) {
737 set = isl_ast_build_get_stride_constraint(build);
738 dom = isl_set_intersect(dom, set);
741 dom = isl_set_eliminate(dom, isl_dim_set, depth, 1);
742 dom = isl_ast_build_compute_gist(build, dom);
743 guard = isl_set_intersect(guard, dom);
745 return guard;
748 /* Update "graft" based on "sub_build" for the degenerate case.
750 * "build" is the build in which graft->node was created
751 * "sub_build" contains information about the current level itself,
752 * including the single value attained.
754 * We set the initialization part of the for loop to the single
755 * value attained by the current dimension.
756 * The increment and condition are not strictly needed as the are known
757 * to be "1" and "iterator <= value" respectively.
759 static __isl_give isl_ast_graft *refine_degenerate(
760 __isl_take isl_ast_graft *graft, __isl_keep isl_ast_build *build,
761 __isl_keep isl_ast_build *sub_build)
763 isl_pw_aff *value;
765 if (!graft || !sub_build)
766 return isl_ast_graft_free(graft);
768 value = isl_pw_aff_copy(sub_build->value);
770 graft->node->u.f.init = isl_ast_build_expr_from_pw_aff_internal(build,
771 value);
772 if (!graft->node->u.f.init)
773 return isl_ast_graft_free(graft);
775 return graft;
778 /* Return the intersection of constraints in "list" as a set.
780 static __isl_give isl_set *intersect_constraints(
781 __isl_keep isl_constraint_list *list)
783 int i, n;
784 isl_basic_set *bset;
786 n = isl_constraint_list_n_constraint(list);
787 if (n < 1)
788 isl_die(isl_constraint_list_get_ctx(list), isl_error_internal,
789 "expecting at least one constraint", return NULL);
791 bset = isl_basic_set_from_constraint(
792 isl_constraint_list_get_constraint(list, 0));
793 for (i = 1; i < n; ++i) {
794 isl_basic_set *bset_i;
796 bset_i = isl_basic_set_from_constraint(
797 isl_constraint_list_get_constraint(list, i));
798 bset = isl_basic_set_intersect(bset, bset_i);
801 return isl_set_from_basic_set(bset);
804 /* Compute the constraints on the outer dimensions enforced by
805 * graft->node and add those constraints to graft->enforced,
806 * in case the upper bound is expressed as a set "upper".
808 * In particular, if l(...) is a lower bound in "lower", and
810 * -a i + f(...) >= 0 or a i <= f(...)
812 * is an upper bound ocnstraint on the current dimension i,
813 * then the for loop enforces the constraint
815 * -a l(...) + f(...) >= 0 or a l(...) <= f(...)
817 * We therefore simply take each lower bound in turn, plug it into
818 * the upper bounds and compute the intersection over all lower bounds.
820 * If a lower bound is a rational expression, then
821 * isl_basic_set_preimage_multi_aff will force this rational
822 * expression to have only integer values. However, the loop
823 * itself does not enforce this integrality constraint. We therefore
824 * use the ceil of the lower bounds instead of the lower bounds themselves.
825 * Other constraints will make sure that the for loop is only executed
826 * when each of the lower bounds attains an integral value.
827 * In particular, potentially rational values only occur in
828 * lower_bound if the offset is a (seemingly) rational expression,
829 * but then outer conditions will make sure that this rational expression
830 * only attains integer values.
832 static __isl_give isl_ast_graft *set_enforced_from_set(
833 __isl_take isl_ast_graft *graft,
834 __isl_keep isl_pw_aff_list *lower, int pos, __isl_keep isl_set *upper)
836 isl_space *space;
837 isl_basic_set *enforced;
838 isl_pw_multi_aff *pma;
839 int i, n;
841 if (!graft || !lower)
842 return isl_ast_graft_free(graft);
844 space = isl_set_get_space(upper);
845 enforced = isl_basic_set_universe(isl_space_copy(space));
847 space = isl_space_map_from_set(space);
848 pma = isl_pw_multi_aff_identity(space);
850 n = isl_pw_aff_list_n_pw_aff(lower);
851 for (i = 0; i < n; ++i) {
852 isl_pw_aff *pa;
853 isl_set *enforced_i;
854 isl_basic_set *hull;
855 isl_pw_multi_aff *pma_i;
857 pa = isl_pw_aff_list_get_pw_aff(lower, i);
858 pa = isl_pw_aff_ceil(pa);
859 pma_i = isl_pw_multi_aff_copy(pma);
860 pma_i = isl_pw_multi_aff_set_pw_aff(pma_i, pos, pa);
861 enforced_i = isl_set_copy(upper);
862 enforced_i = isl_set_preimage_pw_multi_aff(enforced_i, pma_i);
863 hull = isl_set_simple_hull(enforced_i);
864 enforced = isl_basic_set_intersect(enforced, hull);
867 isl_pw_multi_aff_free(pma);
869 graft = isl_ast_graft_enforce(graft, enforced);
871 return graft;
874 /* Compute the constraints on the outer dimensions enforced by
875 * graft->node and add those constraints to graft->enforced,
876 * in case the upper bound is expressed as
877 * a list of affine expressions "upper".
879 * The enforced condition is that each lower bound expression is less
880 * than or equal to each upper bound expression.
882 static __isl_give isl_ast_graft *set_enforced_from_list(
883 __isl_take isl_ast_graft *graft,
884 __isl_keep isl_pw_aff_list *lower, __isl_keep isl_pw_aff_list *upper)
886 isl_set *cond;
887 isl_basic_set *enforced;
889 lower = isl_pw_aff_list_copy(lower);
890 upper = isl_pw_aff_list_copy(upper);
891 cond = isl_pw_aff_list_le_set(lower, upper);
892 enforced = isl_set_simple_hull(cond);
893 graft = isl_ast_graft_enforce(graft, enforced);
895 return graft;
898 /* Does "aff" have a negative constant term?
900 static isl_stat aff_constant_is_negative(__isl_take isl_set *set,
901 __isl_take isl_aff *aff, void *user)
903 int *neg = user;
904 isl_val *v;
906 v = isl_aff_get_constant_val(aff);
907 *neg = isl_val_is_neg(v);
908 isl_val_free(v);
909 isl_set_free(set);
910 isl_aff_free(aff);
912 return *neg ? isl_stat_ok : isl_stat_error;
915 /* Does "pa" have a negative constant term over its entire domain?
917 static isl_stat pw_aff_constant_is_negative(__isl_take isl_pw_aff *pa,
918 void *user)
920 isl_stat r;
921 int *neg = user;
923 r = isl_pw_aff_foreach_piece(pa, &aff_constant_is_negative, user);
924 isl_pw_aff_free(pa);
926 return (*neg && r >= 0) ? isl_stat_ok : isl_stat_error;
929 /* Does each element in "list" have a negative constant term?
931 * The callback terminates the iteration as soon an element has been
932 * found that does not have a negative constant term.
934 static int list_constant_is_negative(__isl_keep isl_pw_aff_list *list)
936 int neg = 1;
938 if (isl_pw_aff_list_foreach(list,
939 &pw_aff_constant_is_negative, &neg) < 0 && neg)
940 return -1;
942 return neg;
945 /* Add 1 to each of the elements in "list", where each of these elements
946 * is defined over the internal schedule space of "build".
948 static __isl_give isl_pw_aff_list *list_add_one(
949 __isl_take isl_pw_aff_list *list, __isl_keep isl_ast_build *build)
951 int i, n;
952 isl_space *space;
953 isl_aff *aff;
954 isl_pw_aff *one;
956 space = isl_ast_build_get_space(build, 1);
957 aff = isl_aff_zero_on_domain(isl_local_space_from_space(space));
958 aff = isl_aff_add_constant_si(aff, 1);
959 one = isl_pw_aff_from_aff(aff);
961 n = isl_pw_aff_list_n_pw_aff(list);
962 for (i = 0; i < n; ++i) {
963 isl_pw_aff *pa;
964 pa = isl_pw_aff_list_get_pw_aff(list, i);
965 pa = isl_pw_aff_add(pa, isl_pw_aff_copy(one));
966 list = isl_pw_aff_list_set_pw_aff(list, i, pa);
969 isl_pw_aff_free(one);
971 return list;
974 /* Set the condition part of the for node graft->node in case
975 * the upper bound is represented as a list of piecewise affine expressions.
977 * In particular, set the condition to
979 * iterator <= min(list of upper bounds)
981 * If each of the upper bounds has a negative constant term, then
982 * set the condition to
984 * iterator < min(list of (upper bound + 1)s)
987 static __isl_give isl_ast_graft *set_for_cond_from_list(
988 __isl_take isl_ast_graft *graft, __isl_keep isl_pw_aff_list *list,
989 __isl_keep isl_ast_build *build)
991 int neg;
992 isl_ast_expr *bound, *iterator, *cond;
993 enum isl_ast_op_type type = isl_ast_op_le;
995 if (!graft || !list)
996 return isl_ast_graft_free(graft);
998 neg = list_constant_is_negative(list);
999 if (neg < 0)
1000 return isl_ast_graft_free(graft);
1001 list = isl_pw_aff_list_copy(list);
1002 if (neg) {
1003 list = list_add_one(list, build);
1004 type = isl_ast_op_lt;
1007 bound = reduce_list(isl_ast_op_min, list, build);
1008 iterator = isl_ast_expr_copy(graft->node->u.f.iterator);
1009 cond = isl_ast_expr_alloc_binary(type, iterator, bound);
1010 graft->node->u.f.cond = cond;
1012 isl_pw_aff_list_free(list);
1013 if (!graft->node->u.f.cond)
1014 return isl_ast_graft_free(graft);
1015 return graft;
1018 /* Set the condition part of the for node graft->node in case
1019 * the upper bound is represented as a set.
1021 static __isl_give isl_ast_graft *set_for_cond_from_set(
1022 __isl_take isl_ast_graft *graft, __isl_keep isl_set *set,
1023 __isl_keep isl_ast_build *build)
1025 isl_ast_expr *cond;
1027 if (!graft)
1028 return NULL;
1030 cond = isl_ast_build_expr_from_set_internal(build, isl_set_copy(set));
1031 graft->node->u.f.cond = cond;
1032 if (!graft->node->u.f.cond)
1033 return isl_ast_graft_free(graft);
1034 return graft;
1037 /* Construct an isl_ast_expr for the increment (i.e., stride) of
1038 * the current dimension.
1040 static __isl_give isl_ast_expr *for_inc(__isl_keep isl_ast_build *build)
1042 int depth;
1043 isl_val *v;
1044 isl_ctx *ctx;
1046 if (!build)
1047 return NULL;
1048 ctx = isl_ast_build_get_ctx(build);
1049 depth = isl_ast_build_get_depth(build);
1051 if (!isl_ast_build_has_stride(build, depth))
1052 return isl_ast_expr_alloc_int_si(ctx, 1);
1054 v = isl_ast_build_get_stride(build, depth);
1055 return isl_ast_expr_from_val(v);
1058 /* Should we express the loop condition as
1060 * iterator <= min(list of upper bounds)
1062 * or as a conjunction of constraints?
1064 * The first is constructed from a list of upper bounds.
1065 * The second is constructed from a set.
1067 * If there are no upper bounds in "constraints", then this could mean
1068 * that "domain" simply doesn't have an upper bound or that we didn't
1069 * pick any upper bound. In the first case, we want to generate the
1070 * loop condition as a(n empty) conjunction of constraints
1071 * In the second case, we will compute
1072 * a single upper bound from "domain" and so we use the list form.
1074 * If there are upper bounds in "constraints",
1075 * then we use the list form iff the atomic_upper_bound option is set.
1077 static int use_upper_bound_list(isl_ctx *ctx, int n_upper,
1078 __isl_keep isl_set *domain, int depth)
1080 if (n_upper > 0)
1081 return isl_options_get_ast_build_atomic_upper_bound(ctx);
1082 else
1083 return isl_set_dim_has_upper_bound(domain, isl_dim_set, depth);
1086 /* Fill in the expressions of the for node in graft->node.
1088 * In particular,
1089 * - set the initialization part of the loop to the maximum of the lower bounds
1090 * - extract the increment from the stride of the current dimension
1091 * - construct the for condition either based on a list of upper bounds
1092 * or on a set of upper bound constraints.
1094 static __isl_give isl_ast_graft *set_for_node_expressions(
1095 __isl_take isl_ast_graft *graft, __isl_keep isl_pw_aff_list *lower,
1096 int use_list, __isl_keep isl_pw_aff_list *upper_list,
1097 __isl_keep isl_set *upper_set, __isl_keep isl_ast_build *build)
1099 isl_ast_node *node;
1101 if (!graft)
1102 return NULL;
1104 build = isl_ast_build_copy(build);
1106 node = graft->node;
1107 node->u.f.init = reduce_list(isl_ast_op_max, lower, build);
1108 node->u.f.inc = for_inc(build);
1110 if (!node->u.f.init || !node->u.f.inc)
1111 graft = isl_ast_graft_free(graft);
1113 if (use_list)
1114 graft = set_for_cond_from_list(graft, upper_list, build);
1115 else
1116 graft = set_for_cond_from_set(graft, upper_set, build);
1118 isl_ast_build_free(build);
1120 return graft;
1123 /* Update "graft" based on "bounds" and "domain" for the generic,
1124 * non-degenerate, case.
1126 * "c_lower" and "c_upper" contain the lower and upper bounds
1127 * that the loop node should express.
1128 * "domain" is the subset of the intersection of the constraints
1129 * for which some code is executed.
1131 * There may be zero lower bounds or zero upper bounds in "constraints"
1132 * in case the list of constraints was created
1133 * based on the atomic option or based on separation with explicit bounds.
1134 * In that case, we use "domain" to derive lower and/or upper bounds.
1136 * We first compute a list of one or more lower bounds.
1138 * Then we decide if we want to express the condition as
1140 * iterator <= min(list of upper bounds)
1142 * or as a conjunction of constraints.
1144 * The set of enforced constraints is then computed either based on
1145 * a list of upper bounds or on a set of upper bound constraints.
1146 * We do not compute any enforced constraints if we were forced
1147 * to compute a lower or upper bound using exact_bound. The domains
1148 * of the resulting expressions may imply some bounds on outer dimensions
1149 * that we do not want to appear in the enforced constraints since
1150 * they are not actually enforced by the corresponding code.
1152 * Finally, we fill in the expressions of the for node.
1154 static __isl_give isl_ast_graft *refine_generic_bounds(
1155 __isl_take isl_ast_graft *graft,
1156 __isl_take isl_constraint_list *c_lower,
1157 __isl_take isl_constraint_list *c_upper,
1158 __isl_keep isl_set *domain, __isl_keep isl_ast_build *build)
1160 int depth;
1161 isl_ctx *ctx;
1162 isl_pw_aff_list *lower;
1163 int use_list;
1164 isl_set *upper_set = NULL;
1165 isl_pw_aff_list *upper_list = NULL;
1166 int n_lower, n_upper;
1168 if (!graft || !c_lower || !c_upper || !build)
1169 goto error;
1171 depth = isl_ast_build_get_depth(build);
1172 ctx = isl_ast_graft_get_ctx(graft);
1174 n_lower = isl_constraint_list_n_constraint(c_lower);
1175 n_upper = isl_constraint_list_n_constraint(c_upper);
1177 use_list = use_upper_bound_list(ctx, n_upper, domain, depth);
1179 lower = lower_bounds(c_lower, depth, domain, build);
1181 if (use_list)
1182 upper_list = upper_bounds(c_upper, depth, domain, build);
1183 else if (n_upper > 0)
1184 upper_set = intersect_constraints(c_upper);
1185 else
1186 upper_set = isl_set_universe(isl_set_get_space(domain));
1188 if (n_lower == 0 || n_upper == 0)
1190 else if (use_list)
1191 graft = set_enforced_from_list(graft, lower, upper_list);
1192 else
1193 graft = set_enforced_from_set(graft, lower, depth, upper_set);
1195 graft = set_for_node_expressions(graft, lower, use_list, upper_list,
1196 upper_set, build);
1198 isl_pw_aff_list_free(lower);
1199 isl_pw_aff_list_free(upper_list);
1200 isl_set_free(upper_set);
1201 isl_constraint_list_free(c_lower);
1202 isl_constraint_list_free(c_upper);
1204 return graft;
1205 error:
1206 isl_constraint_list_free(c_lower);
1207 isl_constraint_list_free(c_upper);
1208 return isl_ast_graft_free(graft);
1211 /* Internal data structure used inside count_constraints to keep
1212 * track of the number of constraints that are independent of dimension "pos",
1213 * the lower bounds in "pos" and the upper bounds in "pos".
1215 struct isl_ast_count_constraints_data {
1216 int pos;
1218 int n_indep;
1219 int n_lower;
1220 int n_upper;
1223 /* Increment data->n_indep, data->lower or data->upper depending
1224 * on whether "c" is independenct of dimensions data->pos,
1225 * a lower bound or an upper bound.
1227 static isl_stat count_constraints(__isl_take isl_constraint *c, void *user)
1229 struct isl_ast_count_constraints_data *data = user;
1231 if (isl_constraint_is_lower_bound(c, isl_dim_set, data->pos))
1232 data->n_lower++;
1233 else if (isl_constraint_is_upper_bound(c, isl_dim_set, data->pos))
1234 data->n_upper++;
1235 else
1236 data->n_indep++;
1238 isl_constraint_free(c);
1240 return isl_stat_ok;
1243 /* Update "graft" based on "bounds" and "domain" for the generic,
1244 * non-degenerate, case.
1246 * "list" respresent the list of bounds that need to be encoded by
1247 * the for loop. Only the constraints that involve the iterator
1248 * are relevant here. The other constraints are taken care of by
1249 * the caller and are included in the generated constraints of "build".
1250 * "domain" is the subset of the intersection of the constraints
1251 * for which some code is executed.
1252 * "build" is the build in which graft->node was created.
1254 * We separate lower bounds, upper bounds and constraints that
1255 * are independent of the loop iterator.
1257 * The actual for loop bounds are generated in refine_generic_bounds.
1259 static __isl_give isl_ast_graft *refine_generic_split(
1260 __isl_take isl_ast_graft *graft, __isl_take isl_constraint_list *list,
1261 __isl_keep isl_set *domain, __isl_keep isl_ast_build *build)
1263 struct isl_ast_count_constraints_data data;
1264 isl_constraint_list *lower;
1265 isl_constraint_list *upper;
1267 if (!list)
1268 return isl_ast_graft_free(graft);
1270 data.pos = isl_ast_build_get_depth(build);
1272 list = isl_constraint_list_sort(list, &cmp_constraint, &data.pos);
1273 if (!list)
1274 return isl_ast_graft_free(graft);
1276 data.n_indep = data.n_lower = data.n_upper = 0;
1277 if (isl_constraint_list_foreach(list, &count_constraints, &data) < 0) {
1278 isl_constraint_list_free(list);
1279 return isl_ast_graft_free(graft);
1282 lower = isl_constraint_list_drop(list, 0, data.n_indep);
1283 upper = isl_constraint_list_copy(lower);
1284 lower = isl_constraint_list_drop(lower, data.n_lower, data.n_upper);
1285 upper = isl_constraint_list_drop(upper, 0, data.n_lower);
1287 return refine_generic_bounds(graft, lower, upper, domain, build);
1290 /* Update "graft" based on "bounds" and "domain" for the generic,
1291 * non-degenerate, case.
1293 * "bounds" respresent the bounds that need to be encoded by
1294 * the for loop (or a guard around the for loop).
1295 * "domain" is the subset of "bounds" for which some code is executed.
1296 * "build" is the build in which graft->node was created.
1298 * We break up "bounds" into a list of constraints and continue with
1299 * refine_generic_split.
1301 static __isl_give isl_ast_graft *refine_generic(
1302 __isl_take isl_ast_graft *graft,
1303 __isl_keep isl_basic_set *bounds, __isl_keep isl_set *domain,
1304 __isl_keep isl_ast_build *build)
1306 isl_constraint_list *list;
1308 if (!build || !graft)
1309 return isl_ast_graft_free(graft);
1311 list = isl_basic_set_get_constraint_list(bounds);
1313 graft = refine_generic_split(graft, list, domain, build);
1315 return graft;
1318 /* Create a for node for the current level.
1320 * Mark the for node degenerate if "degenerate" is set.
1322 static __isl_give isl_ast_node *create_for(__isl_keep isl_ast_build *build,
1323 int degenerate)
1325 int depth;
1326 isl_id *id;
1327 isl_ast_node *node;
1329 if (!build)
1330 return NULL;
1332 depth = isl_ast_build_get_depth(build);
1333 id = isl_ast_build_get_iterator_id(build, depth);
1334 node = isl_ast_node_alloc_for(id);
1335 if (degenerate)
1336 node = isl_ast_node_for_mark_degenerate(node);
1338 return node;
1341 /* If the ast_build_exploit_nested_bounds option is set, then return
1342 * the constraints enforced by all elements in "list".
1343 * Otherwise, return the universe.
1345 static __isl_give isl_basic_set *extract_shared_enforced(
1346 __isl_keep isl_ast_graft_list *list, __isl_keep isl_ast_build *build)
1348 isl_ctx *ctx;
1349 isl_space *space;
1351 if (!list)
1352 return NULL;
1354 ctx = isl_ast_graft_list_get_ctx(list);
1355 if (isl_options_get_ast_build_exploit_nested_bounds(ctx))
1356 return isl_ast_graft_list_extract_shared_enforced(list, build);
1358 space = isl_ast_build_get_space(build, 1);
1359 return isl_basic_set_universe(space);
1362 /* Return the pending constraints of "build" that are not already taken
1363 * care of (by a combination of "enforced" and the generated constraints
1364 * of "build").
1366 static __isl_give isl_set *extract_pending(__isl_keep isl_ast_build *build,
1367 __isl_keep isl_basic_set *enforced)
1369 isl_set *guard, *context;
1371 guard = isl_ast_build_get_pending(build);
1372 context = isl_set_from_basic_set(isl_basic_set_copy(enforced));
1373 context = isl_set_intersect(context,
1374 isl_ast_build_get_generated(build));
1375 return isl_set_gist(guard, context);
1378 /* Create an AST node for the current dimension based on
1379 * the schedule domain "bounds" and return the node encapsulated
1380 * in an isl_ast_graft.
1382 * "executed" is the current inverse schedule, taking into account
1383 * the bounds in "bounds"
1384 * "domain" is the domain of "executed", with inner dimensions projected out.
1385 * It may be a strict subset of "bounds" in case "bounds" was created
1386 * based on the atomic option or based on separation with explicit bounds.
1388 * "domain" may satisfy additional equalities that result
1389 * from intersecting "executed" with "bounds" in add_node.
1390 * It may also satisfy some global constraints that were dropped out because
1391 * we performed separation with explicit bounds.
1392 * The very first step is then to copy these constraints to "bounds".
1394 * Since we may be calling before_each_for and after_each_for
1395 * callbacks, we record the current inverse schedule in the build.
1397 * We consider three builds,
1398 * "build" is the one in which the current level is created,
1399 * "body_build" is the build in which the next level is created,
1400 * "sub_build" is essentially the same as "body_build", except that
1401 * the depth has not been increased yet.
1403 * "build" already contains information (in strides and offsets)
1404 * about the strides at the current level, but this information is not
1405 * reflected in the build->domain.
1406 * We first add this information and the "bounds" to the sub_build->domain.
1407 * isl_ast_build_set_loop_bounds adds the stride information and
1408 * checks whether the current dimension attains
1409 * only a single value and whether this single value can be represented using
1410 * a single affine expression.
1411 * In the first case, the current level is considered "degenerate".
1412 * In the second, sub-case, the current level is considered "eliminated".
1413 * Eliminated levels don't need to be reflected in the AST since we can
1414 * simply plug in the affine expression. For degenerate, but non-eliminated,
1415 * levels, we do introduce a for node, but mark is as degenerate so that
1416 * it can be printed as an assignment of the single value to the loop
1417 * "iterator".
1419 * If the current level is eliminated, we explicitly plug in the value
1420 * for the current level found by isl_ast_build_set_loop_bounds in the
1421 * inverse schedule. This ensures that if we are working on a slice
1422 * of the domain based on information available in the inverse schedule
1423 * and the build domain, that then this information is also reflected
1424 * in the inverse schedule. This operation also eliminates the current
1425 * dimension from the inverse schedule making sure no inner dimensions depend
1426 * on the current dimension. Otherwise, we create a for node, marking
1427 * it degenerate if appropriate. The initial for node is still incomplete
1428 * and will be completed in either refine_degenerate or refine_generic.
1430 * We then generate a sequence of grafts for the next level,
1431 * create a surrounding graft for the current level and insert
1432 * the for node we created (if the current level is not eliminated).
1433 * Before creating a graft for the current level, we first extract
1434 * hoistable constraints from the child guards and combine them
1435 * with the pending constraints in the build. These constraints
1436 * are used to simplify the child guards and then added to the guard
1437 * of the current graft to ensure that they will be generated.
1438 * If the hoisted guard is a disjunction, then we use it directly
1439 * to gist the guards on the children before intersect it with the
1440 * pending constraints. We do so because this disjunction is typically
1441 * identical to the guards on the children such that these guards
1442 * can be effectively removed completely. After the intersection,
1443 * the gist operation would have a harder time figuring this out.
1445 * Finally, we set the bounds of the for loop in either
1446 * refine_degenerate or refine_generic.
1447 * We do so in a context where the pending constraints of the build
1448 * have been replaced by the guard of the current graft.
1450 static __isl_give isl_ast_graft *create_node_scaled(
1451 __isl_take isl_union_map *executed,
1452 __isl_take isl_basic_set *bounds, __isl_take isl_set *domain,
1453 __isl_take isl_ast_build *build)
1455 int depth;
1456 int degenerate, eliminated;
1457 isl_basic_set *hull;
1458 isl_basic_set *enforced;
1459 isl_set *guard, *hoisted;
1460 isl_ast_node *node = NULL;
1461 isl_ast_graft *graft;
1462 isl_ast_graft_list *children;
1463 isl_ast_build *sub_build;
1464 isl_ast_build *body_build;
1466 domain = isl_ast_build_eliminate_divs(build, domain);
1467 domain = isl_set_detect_equalities(domain);
1468 hull = isl_set_unshifted_simple_hull(isl_set_copy(domain));
1469 bounds = isl_basic_set_intersect(bounds, hull);
1470 build = isl_ast_build_set_executed(build, isl_union_map_copy(executed));
1472 depth = isl_ast_build_get_depth(build);
1473 sub_build = isl_ast_build_copy(build);
1474 bounds = isl_basic_set_remove_redundancies(bounds);
1475 bounds = isl_ast_build_specialize_basic_set(sub_build, bounds);
1476 sub_build = isl_ast_build_set_loop_bounds(sub_build,
1477 isl_basic_set_copy(bounds));
1478 degenerate = isl_ast_build_has_value(sub_build);
1479 eliminated = isl_ast_build_has_affine_value(sub_build, depth);
1480 if (degenerate < 0 || eliminated < 0)
1481 executed = isl_union_map_free(executed);
1482 if (!degenerate)
1483 bounds = isl_ast_build_compute_gist_basic_set(build, bounds);
1484 sub_build = isl_ast_build_set_pending_generated(sub_build,
1485 isl_basic_set_copy(bounds));
1486 if (eliminated)
1487 executed = plug_in_values(executed, sub_build);
1488 else
1489 node = create_for(build, degenerate);
1491 body_build = isl_ast_build_copy(sub_build);
1492 body_build = isl_ast_build_increase_depth(body_build);
1493 if (!eliminated)
1494 node = before_each_for(node, body_build);
1495 children = generate_next_level(executed,
1496 isl_ast_build_copy(body_build));
1498 enforced = extract_shared_enforced(children, build);
1499 guard = extract_pending(sub_build, enforced);
1500 hoisted = isl_ast_graft_list_extract_hoistable_guard(children, build);
1501 if (isl_set_n_basic_set(hoisted) > 1)
1502 children = isl_ast_graft_list_gist_guards(children,
1503 isl_set_copy(hoisted));
1504 guard = isl_set_intersect(guard, hoisted);
1505 if (!eliminated)
1506 guard = add_implied_guards(guard, degenerate, bounds, build);
1508 graft = isl_ast_graft_alloc_from_children(children,
1509 isl_set_copy(guard), enforced, build, sub_build);
1511 if (!eliminated) {
1512 isl_ast_build *for_build;
1514 graft = isl_ast_graft_insert_for(graft, node);
1515 for_build = isl_ast_build_copy(build);
1516 for_build = isl_ast_build_replace_pending_by_guard(for_build,
1517 isl_set_copy(guard));
1518 if (degenerate)
1519 graft = refine_degenerate(graft, for_build, sub_build);
1520 else
1521 graft = refine_generic(graft, bounds,
1522 domain, for_build);
1523 isl_ast_build_free(for_build);
1525 isl_set_free(guard);
1526 if (!eliminated)
1527 graft = after_each_for(graft, body_build);
1529 isl_ast_build_free(body_build);
1530 isl_ast_build_free(sub_build);
1531 isl_ast_build_free(build);
1532 isl_basic_set_free(bounds);
1533 isl_set_free(domain);
1535 return graft;
1538 /* Internal data structure for checking if all constraints involving
1539 * the input dimension "depth" are such that the other coefficients
1540 * are multiples of "m", reducing "m" if they are not.
1541 * If "m" is reduced all the way down to "1", then the check has failed
1542 * and we break out of the iteration.
1544 struct isl_check_scaled_data {
1545 int depth;
1546 isl_val *m;
1549 /* If constraint "c" involves the input dimension data->depth,
1550 * then make sure that all the other coefficients are multiples of data->m,
1551 * reducing data->m if needed.
1552 * Break out of the iteration if data->m has become equal to "1".
1554 static isl_stat constraint_check_scaled(__isl_take isl_constraint *c,
1555 void *user)
1557 struct isl_check_scaled_data *data = user;
1558 int i, j, n;
1559 enum isl_dim_type t[] = { isl_dim_param, isl_dim_in, isl_dim_out,
1560 isl_dim_div };
1562 if (!isl_constraint_involves_dims(c, isl_dim_in, data->depth, 1)) {
1563 isl_constraint_free(c);
1564 return isl_stat_ok;
1567 for (i = 0; i < 4; ++i) {
1568 n = isl_constraint_dim(c, t[i]);
1569 for (j = 0; j < n; ++j) {
1570 isl_val *d;
1572 if (t[i] == isl_dim_in && j == data->depth)
1573 continue;
1574 if (!isl_constraint_involves_dims(c, t[i], j, 1))
1575 continue;
1576 d = isl_constraint_get_coefficient_val(c, t[i], j);
1577 data->m = isl_val_gcd(data->m, d);
1578 if (isl_val_is_one(data->m))
1579 break;
1581 if (j < n)
1582 break;
1585 isl_constraint_free(c);
1587 return i < 4 ? isl_stat_error : isl_stat_ok;
1590 /* For each constraint of "bmap" that involves the input dimension data->depth,
1591 * make sure that all the other coefficients are multiples of data->m,
1592 * reducing data->m if needed.
1593 * Break out of the iteration if data->m has become equal to "1".
1595 static isl_stat basic_map_check_scaled(__isl_take isl_basic_map *bmap,
1596 void *user)
1598 isl_stat r;
1600 r = isl_basic_map_foreach_constraint(bmap,
1601 &constraint_check_scaled, user);
1602 isl_basic_map_free(bmap);
1604 return r;
1607 /* For each constraint of "map" that involves the input dimension data->depth,
1608 * make sure that all the other coefficients are multiples of data->m,
1609 * reducing data->m if needed.
1610 * Break out of the iteration if data->m has become equal to "1".
1612 static isl_stat map_check_scaled(__isl_take isl_map *map, void *user)
1614 isl_stat r;
1616 r = isl_map_foreach_basic_map(map, &basic_map_check_scaled, user);
1617 isl_map_free(map);
1619 return r;
1622 /* Create an AST node for the current dimension based on
1623 * the schedule domain "bounds" and return the node encapsulated
1624 * in an isl_ast_graft.
1626 * "executed" is the current inverse schedule, taking into account
1627 * the bounds in "bounds"
1628 * "domain" is the domain of "executed", with inner dimensions projected out.
1631 * Before moving on to the actual AST node construction in create_node_scaled,
1632 * we first check if the current dimension is strided and if we can scale
1633 * down this stride. Note that we only do this if the ast_build_scale_strides
1634 * option is set.
1636 * In particular, let the current dimension take on values
1638 * f + s a
1640 * with a an integer. We check if we can find an integer m that (obviously)
1641 * divides both f and s.
1643 * If so, we check if the current dimension only appears in constraints
1644 * where the coefficients of the other variables are multiples of m.
1645 * We perform this extra check to avoid the risk of introducing
1646 * divisions by scaling down the current dimension.
1648 * If so, we scale the current dimension down by a factor of m.
1649 * That is, we plug in
1651 * i = m i' (1)
1653 * Note that in principle we could always scale down strided loops
1654 * by plugging in
1656 * i = f + s i'
1658 * but this may result in i' taking on larger values than the original i,
1659 * due to the shift by "f".
1660 * By constrast, the scaling in (1) can only reduce the (absolute) value "i".
1662 static __isl_give isl_ast_graft *create_node(__isl_take isl_union_map *executed,
1663 __isl_take isl_basic_set *bounds, __isl_take isl_set *domain,
1664 __isl_take isl_ast_build *build)
1666 struct isl_check_scaled_data data;
1667 isl_ctx *ctx;
1668 isl_aff *offset;
1669 isl_val *d;
1671 ctx = isl_ast_build_get_ctx(build);
1672 if (!isl_options_get_ast_build_scale_strides(ctx))
1673 return create_node_scaled(executed, bounds, domain, build);
1675 data.depth = isl_ast_build_get_depth(build);
1676 if (!isl_ast_build_has_stride(build, data.depth))
1677 return create_node_scaled(executed, bounds, domain, build);
1679 offset = isl_ast_build_get_offset(build, data.depth);
1680 data.m = isl_ast_build_get_stride(build, data.depth);
1681 if (!data.m)
1682 offset = isl_aff_free(offset);
1683 offset = isl_aff_scale_down_val(offset, isl_val_copy(data.m));
1684 d = isl_aff_get_denominator_val(offset);
1685 if (!d)
1686 executed = isl_union_map_free(executed);
1688 if (executed && isl_val_is_divisible_by(data.m, d))
1689 data.m = isl_val_div(data.m, d);
1690 else {
1691 data.m = isl_val_set_si(data.m, 1);
1692 isl_val_free(d);
1695 if (!isl_val_is_one(data.m)) {
1696 if (isl_union_map_foreach_map(executed, &map_check_scaled,
1697 &data) < 0 &&
1698 !isl_val_is_one(data.m))
1699 executed = isl_union_map_free(executed);
1702 if (!isl_val_is_one(data.m)) {
1703 isl_space *space;
1704 isl_multi_aff *ma;
1705 isl_aff *aff;
1706 isl_map *map;
1707 isl_union_map *umap;
1709 space = isl_ast_build_get_space(build, 1);
1710 space = isl_space_map_from_set(space);
1711 ma = isl_multi_aff_identity(space);
1712 aff = isl_multi_aff_get_aff(ma, data.depth);
1713 aff = isl_aff_scale_val(aff, isl_val_copy(data.m));
1714 ma = isl_multi_aff_set_aff(ma, data.depth, aff);
1716 bounds = isl_basic_set_preimage_multi_aff(bounds,
1717 isl_multi_aff_copy(ma));
1718 domain = isl_set_preimage_multi_aff(domain,
1719 isl_multi_aff_copy(ma));
1720 map = isl_map_reverse(isl_map_from_multi_aff(ma));
1721 umap = isl_union_map_from_map(map);
1722 executed = isl_union_map_apply_domain(executed,
1723 isl_union_map_copy(umap));
1724 build = isl_ast_build_scale_down(build, isl_val_copy(data.m),
1725 umap);
1727 isl_aff_free(offset);
1728 isl_val_free(data.m);
1730 return create_node_scaled(executed, bounds, domain, build);
1733 /* Add the basic set to the list that "user" points to.
1735 static isl_stat collect_basic_set(__isl_take isl_basic_set *bset, void *user)
1737 isl_basic_set_list **list = user;
1739 *list = isl_basic_set_list_add(*list, bset);
1741 return isl_stat_ok;
1744 /* Extract the basic sets of "set" and collect them in an isl_basic_set_list.
1746 static __isl_give isl_basic_set_list *isl_basic_set_list_from_set(
1747 __isl_take isl_set *set)
1749 int n;
1750 isl_ctx *ctx;
1751 isl_basic_set_list *list;
1753 if (!set)
1754 return NULL;
1756 ctx = isl_set_get_ctx(set);
1758 n = isl_set_n_basic_set(set);
1759 list = isl_basic_set_list_alloc(ctx, n);
1760 if (isl_set_foreach_basic_set(set, &collect_basic_set, &list) < 0)
1761 list = isl_basic_set_list_free(list);
1763 isl_set_free(set);
1764 return list;
1767 /* Generate code for the schedule domain "bounds"
1768 * and add the result to "list".
1770 * We mainly detect strides here and check if the bounds do not
1771 * conflict with the current build domain
1772 * and then pass over control to create_node.
1774 * "bounds" reflects the bounds on the current dimension and possibly
1775 * some extra conditions on outer dimensions.
1776 * It does not, however, include any divs involving the current dimension,
1777 * so it does not capture any stride constraints.
1778 * We therefore need to compute that part of the schedule domain that
1779 * intersects with "bounds" and derive the strides from the result.
1781 static __isl_give isl_ast_graft_list *add_node(
1782 __isl_take isl_ast_graft_list *list, __isl_take isl_union_map *executed,
1783 __isl_take isl_basic_set *bounds, __isl_take isl_ast_build *build)
1785 isl_ast_graft *graft;
1786 isl_set *domain = NULL;
1787 isl_union_set *uset;
1788 int empty, disjoint;
1790 uset = isl_union_set_from_basic_set(isl_basic_set_copy(bounds));
1791 executed = isl_union_map_intersect_domain(executed, uset);
1792 empty = isl_union_map_is_empty(executed);
1793 if (empty < 0)
1794 goto error;
1795 if (empty)
1796 goto done;
1798 uset = isl_union_map_domain(isl_union_map_copy(executed));
1799 domain = isl_set_from_union_set(uset);
1800 domain = isl_ast_build_specialize(build, domain);
1802 domain = isl_set_compute_divs(domain);
1803 domain = isl_ast_build_eliminate_inner(build, domain);
1804 disjoint = isl_set_is_disjoint(domain, build->domain);
1805 if (disjoint < 0)
1806 goto error;
1807 if (disjoint)
1808 goto done;
1810 build = isl_ast_build_detect_strides(build, isl_set_copy(domain));
1812 graft = create_node(executed, bounds, domain,
1813 isl_ast_build_copy(build));
1814 list = isl_ast_graft_list_add(list, graft);
1815 isl_ast_build_free(build);
1816 return list;
1817 error:
1818 list = isl_ast_graft_list_free(list);
1819 done:
1820 isl_set_free(domain);
1821 isl_basic_set_free(bounds);
1822 isl_union_map_free(executed);
1823 isl_ast_build_free(build);
1824 return list;
1827 /* Does any element of i follow or coincide with any element of j
1828 * at the current depth for equal values of the outer dimensions?
1830 static isl_bool domain_follows_at_depth(__isl_keep isl_basic_set *i,
1831 __isl_keep isl_basic_set *j, void *user)
1833 int depth = *(int *) user;
1834 isl_basic_map *test;
1835 isl_bool empty;
1836 int l;
1838 test = isl_basic_map_from_domain_and_range(isl_basic_set_copy(i),
1839 isl_basic_set_copy(j));
1840 for (l = 0; l < depth; ++l)
1841 test = isl_basic_map_equate(test, isl_dim_in, l,
1842 isl_dim_out, l);
1843 test = isl_basic_map_order_ge(test, isl_dim_in, depth,
1844 isl_dim_out, depth);
1845 empty = isl_basic_map_is_empty(test);
1846 isl_basic_map_free(test);
1848 return empty < 0 ? isl_bool_error : !empty;
1851 /* Split up each element of "list" into a part that is related to "bset"
1852 * according to "gt" and a part that is not.
1853 * Return a list that consist of "bset" and all the pieces.
1855 static __isl_give isl_basic_set_list *add_split_on(
1856 __isl_take isl_basic_set_list *list, __isl_take isl_basic_set *bset,
1857 __isl_keep isl_basic_map *gt)
1859 int i, n;
1860 isl_basic_set_list *res;
1862 if (!list)
1863 bset = isl_basic_set_free(bset);
1865 gt = isl_basic_map_copy(gt);
1866 gt = isl_basic_map_intersect_domain(gt, isl_basic_set_copy(bset));
1867 n = isl_basic_set_list_n_basic_set(list);
1868 res = isl_basic_set_list_from_basic_set(bset);
1869 for (i = 0; res && i < n; ++i) {
1870 isl_basic_set *bset;
1871 isl_set *set1, *set2;
1872 isl_basic_map *bmap;
1873 int empty;
1875 bset = isl_basic_set_list_get_basic_set(list, i);
1876 bmap = isl_basic_map_copy(gt);
1877 bmap = isl_basic_map_intersect_range(bmap, bset);
1878 bset = isl_basic_map_range(bmap);
1879 empty = isl_basic_set_is_empty(bset);
1880 if (empty < 0)
1881 res = isl_basic_set_list_free(res);
1882 if (empty) {
1883 isl_basic_set_free(bset);
1884 bset = isl_basic_set_list_get_basic_set(list, i);
1885 res = isl_basic_set_list_add(res, bset);
1886 continue;
1889 res = isl_basic_set_list_add(res, isl_basic_set_copy(bset));
1890 set1 = isl_set_from_basic_set(bset);
1891 bset = isl_basic_set_list_get_basic_set(list, i);
1892 set2 = isl_set_from_basic_set(bset);
1893 set1 = isl_set_subtract(set2, set1);
1894 set1 = isl_set_make_disjoint(set1);
1896 res = isl_basic_set_list_concat(res,
1897 isl_basic_set_list_from_set(set1));
1899 isl_basic_map_free(gt);
1900 isl_basic_set_list_free(list);
1901 return res;
1904 static __isl_give isl_ast_graft_list *generate_sorted_domains(
1905 __isl_keep isl_basic_set_list *domain_list,
1906 __isl_keep isl_union_map *executed,
1907 __isl_keep isl_ast_build *build);
1909 /* Internal data structure for add_nodes.
1911 * "executed" and "build" are extra arguments to be passed to add_node.
1912 * "list" collects the results.
1914 struct isl_add_nodes_data {
1915 isl_union_map *executed;
1916 isl_ast_build *build;
1918 isl_ast_graft_list *list;
1921 /* Generate code for the schedule domains in "scc"
1922 * and add the results to "list".
1924 * The domains in "scc" form a strongly connected component in the ordering.
1925 * If the number of domains in "scc" is larger than 1, then this means
1926 * that we cannot determine a valid ordering for the domains in the component.
1927 * This should be fairly rare because the individual domains
1928 * have been made disjoint first.
1929 * The problem is that the domains may be integrally disjoint but not
1930 * rationally disjoint. For example, we may have domains
1932 * { [i,i] : 0 <= i <= 1 } and { [i,1-i] : 0 <= i <= 1 }
1934 * These two domains have an empty intersection, but their rational
1935 * relaxations do intersect. It is impossible to order these domains
1936 * in the second dimension because the first should be ordered before
1937 * the second for outer dimension equal to 0, while it should be ordered
1938 * after for outer dimension equal to 1.
1940 * This may happen in particular in case of unrolling since the domain
1941 * of each slice is replaced by its simple hull.
1943 * For each basic set i in "scc" and for each of the following basic sets j,
1944 * we split off that part of the basic set i that shares the outer dimensions
1945 * with j and lies before j in the current dimension.
1946 * We collect all the pieces in a new list that replaces "scc".
1948 * While the elements in "scc" should be disjoint, we double-check
1949 * this property to avoid running into an infinite recursion in case
1950 * they intersect due to some internal error.
1952 static isl_stat add_nodes(__isl_take isl_basic_set_list *scc, void *user)
1954 struct isl_add_nodes_data *data = user;
1955 int i, n, depth;
1956 isl_basic_set *bset, *first;
1957 isl_basic_set_list *list;
1958 isl_space *space;
1959 isl_basic_map *gt;
1961 n = isl_basic_set_list_n_basic_set(scc);
1962 bset = isl_basic_set_list_get_basic_set(scc, 0);
1963 if (n == 1) {
1964 isl_basic_set_list_free(scc);
1965 data->list = add_node(data->list,
1966 isl_union_map_copy(data->executed), bset,
1967 isl_ast_build_copy(data->build));
1968 return data->list ? isl_stat_ok : isl_stat_error;
1971 depth = isl_ast_build_get_depth(data->build);
1972 space = isl_basic_set_get_space(bset);
1973 space = isl_space_map_from_set(space);
1974 gt = isl_basic_map_universe(space);
1975 for (i = 0; i < depth; ++i)
1976 gt = isl_basic_map_equate(gt, isl_dim_in, i, isl_dim_out, i);
1977 gt = isl_basic_map_order_gt(gt, isl_dim_in, depth, isl_dim_out, depth);
1979 first = isl_basic_set_copy(bset);
1980 list = isl_basic_set_list_from_basic_set(bset);
1981 for (i = 1; i < n; ++i) {
1982 int disjoint;
1984 bset = isl_basic_set_list_get_basic_set(scc, i);
1986 disjoint = isl_basic_set_is_disjoint(bset, first);
1987 if (disjoint < 0)
1988 list = isl_basic_set_list_free(list);
1989 else if (!disjoint)
1990 isl_die(isl_basic_set_list_get_ctx(scc),
1991 isl_error_internal,
1992 "basic sets in scc are assumed to be disjoint",
1993 list = isl_basic_set_list_free(list));
1995 list = add_split_on(list, bset, gt);
1997 isl_basic_set_free(first);
1998 isl_basic_map_free(gt);
1999 isl_basic_set_list_free(scc);
2000 scc = list;
2001 data->list = isl_ast_graft_list_concat(data->list,
2002 generate_sorted_domains(scc, data->executed, data->build));
2003 isl_basic_set_list_free(scc);
2005 return data->list ? isl_stat_ok : isl_stat_error;
2008 /* Sort the domains in "domain_list" according to the execution order
2009 * at the current depth (for equal values of the outer dimensions),
2010 * generate code for each of them, collecting the results in a list.
2011 * If no code is generated (because the intersection of the inverse schedule
2012 * with the domains turns out to be empty), then an empty list is returned.
2014 * The caller is responsible for ensuring that the basic sets in "domain_list"
2015 * are pair-wise disjoint. It can, however, in principle happen that
2016 * two basic sets should be ordered one way for one value of the outer
2017 * dimensions and the other way for some other value of the outer dimensions.
2018 * We therefore play safe and look for strongly connected components.
2019 * The function add_nodes takes care of handling non-trivial components.
2021 static __isl_give isl_ast_graft_list *generate_sorted_domains(
2022 __isl_keep isl_basic_set_list *domain_list,
2023 __isl_keep isl_union_map *executed, __isl_keep isl_ast_build *build)
2025 isl_ctx *ctx;
2026 struct isl_add_nodes_data data;
2027 int depth;
2028 int n;
2030 if (!domain_list)
2031 return NULL;
2033 ctx = isl_basic_set_list_get_ctx(domain_list);
2034 n = isl_basic_set_list_n_basic_set(domain_list);
2035 data.list = isl_ast_graft_list_alloc(ctx, n);
2036 if (n == 0)
2037 return data.list;
2038 if (n == 1)
2039 return add_node(data.list, isl_union_map_copy(executed),
2040 isl_basic_set_list_get_basic_set(domain_list, 0),
2041 isl_ast_build_copy(build));
2043 depth = isl_ast_build_get_depth(build);
2044 data.executed = executed;
2045 data.build = build;
2046 if (isl_basic_set_list_foreach_scc(domain_list,
2047 &domain_follows_at_depth, &depth,
2048 &add_nodes, &data) < 0)
2049 data.list = isl_ast_graft_list_free(data.list);
2051 return data.list;
2054 /* Do i and j share any values for the outer dimensions?
2056 static isl_bool shared_outer(__isl_keep isl_basic_set *i,
2057 __isl_keep isl_basic_set *j, void *user)
2059 int depth = *(int *) user;
2060 isl_basic_map *test;
2061 isl_bool empty;
2062 int l;
2064 test = isl_basic_map_from_domain_and_range(isl_basic_set_copy(i),
2065 isl_basic_set_copy(j));
2066 for (l = 0; l < depth; ++l)
2067 test = isl_basic_map_equate(test, isl_dim_in, l,
2068 isl_dim_out, l);
2069 empty = isl_basic_map_is_empty(test);
2070 isl_basic_map_free(test);
2072 return empty < 0 ? isl_bool_error : !empty;
2075 /* Internal data structure for generate_sorted_domains_wrap.
2077 * "n" is the total number of basic sets
2078 * "executed" and "build" are extra arguments to be passed
2079 * to generate_sorted_domains.
2081 * "single" is set to 1 by generate_sorted_domains_wrap if there
2082 * is only a single component.
2083 * "list" collects the results.
2085 struct isl_ast_generate_parallel_domains_data {
2086 int n;
2087 isl_union_map *executed;
2088 isl_ast_build *build;
2090 int single;
2091 isl_ast_graft_list *list;
2094 /* Call generate_sorted_domains on "scc", fuse the result into a list
2095 * with either zero or one graft and collect the these single element
2096 * lists into data->list.
2098 * If there is only one component, i.e., if the number of basic sets
2099 * in the current component is equal to the total number of basic sets,
2100 * then data->single is set to 1 and the result of generate_sorted_domains
2101 * is not fused.
2103 static isl_stat generate_sorted_domains_wrap(__isl_take isl_basic_set_list *scc,
2104 void *user)
2106 struct isl_ast_generate_parallel_domains_data *data = user;
2107 isl_ast_graft_list *list;
2109 list = generate_sorted_domains(scc, data->executed, data->build);
2110 data->single = isl_basic_set_list_n_basic_set(scc) == data->n;
2111 if (!data->single)
2112 list = isl_ast_graft_list_fuse(list, data->build);
2113 if (!data->list)
2114 data->list = list;
2115 else
2116 data->list = isl_ast_graft_list_concat(data->list, list);
2118 isl_basic_set_list_free(scc);
2119 if (!data->list)
2120 return isl_stat_error;
2122 return isl_stat_ok;
2125 /* Look for any (weakly connected) components in the "domain_list"
2126 * of domains that share some values of the outer dimensions.
2127 * That is, domains in different components do not share any values
2128 * of the outer dimensions. This means that these components
2129 * can be freely reordered.
2130 * Within each of the components, we sort the domains according
2131 * to the execution order at the current depth.
2133 * If there is more than one component, then generate_sorted_domains_wrap
2134 * fuses the result of each call to generate_sorted_domains
2135 * into a list with either zero or one graft and collects these (at most)
2136 * single element lists into a bigger list. This means that the elements of the
2137 * final list can be freely reordered. In particular, we sort them
2138 * according to an arbitrary but fixed ordering to ease merging of
2139 * graft lists from different components.
2141 static __isl_give isl_ast_graft_list *generate_parallel_domains(
2142 __isl_keep isl_basic_set_list *domain_list,
2143 __isl_keep isl_union_map *executed, __isl_keep isl_ast_build *build)
2145 int depth;
2146 struct isl_ast_generate_parallel_domains_data data;
2148 if (!domain_list)
2149 return NULL;
2151 data.n = isl_basic_set_list_n_basic_set(domain_list);
2152 if (data.n <= 1)
2153 return generate_sorted_domains(domain_list, executed, build);
2155 depth = isl_ast_build_get_depth(build);
2156 data.list = NULL;
2157 data.executed = executed;
2158 data.build = build;
2159 data.single = 0;
2160 if (isl_basic_set_list_foreach_scc(domain_list, &shared_outer, &depth,
2161 &generate_sorted_domains_wrap,
2162 &data) < 0)
2163 data.list = isl_ast_graft_list_free(data.list);
2165 if (!data.single)
2166 data.list = isl_ast_graft_list_sort_guard(data.list);
2168 return data.list;
2171 /* Internal data for separate_domain.
2173 * "explicit" is set if we only want to use explicit bounds.
2175 * "domain" collects the separated domains.
2177 struct isl_separate_domain_data {
2178 isl_ast_build *build;
2179 int explicit;
2180 isl_set *domain;
2183 /* Extract implicit bounds on the current dimension for the executed "map".
2185 * The domain of "map" may involve inner dimensions, so we
2186 * need to eliminate them.
2188 static __isl_give isl_set *implicit_bounds(__isl_take isl_map *map,
2189 __isl_keep isl_ast_build *build)
2191 isl_set *domain;
2193 domain = isl_map_domain(map);
2194 domain = isl_ast_build_eliminate(build, domain);
2196 return domain;
2199 /* Extract explicit bounds on the current dimension for the executed "map".
2201 * Rather than eliminating the inner dimensions as in implicit_bounds,
2202 * we simply drop any constraints involving those inner dimensions.
2203 * The idea is that most bounds that are implied by constraints on the
2204 * inner dimensions will be enforced by for loops and not by explicit guards.
2205 * There is then no need to separate along those bounds.
2207 static __isl_give isl_set *explicit_bounds(__isl_take isl_map *map,
2208 __isl_keep isl_ast_build *build)
2210 isl_set *domain;
2211 int depth, dim;
2213 dim = isl_map_dim(map, isl_dim_out);
2214 map = isl_map_drop_constraints_involving_dims(map, isl_dim_out, 0, dim);
2216 domain = isl_map_domain(map);
2217 depth = isl_ast_build_get_depth(build);
2218 dim = isl_set_dim(domain, isl_dim_set);
2219 domain = isl_set_detect_equalities(domain);
2220 domain = isl_set_drop_constraints_involving_dims(domain,
2221 isl_dim_set, depth + 1, dim - (depth + 1));
2222 domain = isl_set_remove_divs_involving_dims(domain,
2223 isl_dim_set, depth, 1);
2224 domain = isl_set_remove_unknown_divs(domain);
2226 return domain;
2229 /* Split data->domain into pieces that intersect with the range of "map"
2230 * and pieces that do not intersect with the range of "map"
2231 * and then add that part of the range of "map" that does not intersect
2232 * with data->domain.
2234 static isl_stat separate_domain(__isl_take isl_map *map, void *user)
2236 struct isl_separate_domain_data *data = user;
2237 isl_set *domain;
2238 isl_set *d1, *d2;
2240 if (data->explicit)
2241 domain = explicit_bounds(map, data->build);
2242 else
2243 domain = implicit_bounds(map, data->build);
2245 domain = isl_set_coalesce(domain);
2246 domain = isl_set_make_disjoint(domain);
2247 d1 = isl_set_subtract(isl_set_copy(domain), isl_set_copy(data->domain));
2248 d2 = isl_set_subtract(isl_set_copy(data->domain), isl_set_copy(domain));
2249 data->domain = isl_set_intersect(data->domain, domain);
2250 data->domain = isl_set_union(data->domain, d1);
2251 data->domain = isl_set_union(data->domain, d2);
2253 return isl_stat_ok;
2256 /* Separate the schedule domains of "executed".
2258 * That is, break up the domain of "executed" into basic sets,
2259 * such that for each basic set S, every element in S is associated with
2260 * the same domain spaces.
2262 * "space" is the (single) domain space of "executed".
2264 static __isl_give isl_set *separate_schedule_domains(
2265 __isl_take isl_space *space, __isl_take isl_union_map *executed,
2266 __isl_keep isl_ast_build *build)
2268 struct isl_separate_domain_data data = { build };
2269 isl_ctx *ctx;
2271 ctx = isl_ast_build_get_ctx(build);
2272 data.explicit = isl_options_get_ast_build_separation_bounds(ctx) ==
2273 ISL_AST_BUILD_SEPARATION_BOUNDS_EXPLICIT;
2274 data.domain = isl_set_empty(space);
2275 if (isl_union_map_foreach_map(executed, &separate_domain, &data) < 0)
2276 data.domain = isl_set_free(data.domain);
2278 isl_union_map_free(executed);
2279 return data.domain;
2282 /* Temporary data used during the search for a lower bound for unrolling.
2284 * "build" is the build in which the unrolling will be performed
2285 * "domain" is the original set for which to find a lower bound
2286 * "depth" is the dimension for which to find a lower boudn
2287 * "expansion" is the expansion that needs to be applied to "domain"
2288 * in the unrolling that will be performed
2290 * "lower" is the best lower bound found so far. It is NULL if we have not
2291 * found any yet.
2292 * "n" is the corresponding size. If lower is NULL, then the value of n
2293 * is undefined.
2294 * "n_div" is the maximal number of integer divisions in the first
2295 * unrolled iteration (after expansion). It is set to -1 if it hasn't
2296 * been computed yet.
2298 struct isl_find_unroll_data {
2299 isl_ast_build *build;
2300 isl_set *domain;
2301 int depth;
2302 isl_basic_map *expansion;
2304 isl_aff *lower;
2305 int *n;
2306 int n_div;
2309 /* Return the constraint
2311 * i_"depth" = aff + offset
2313 static __isl_give isl_constraint *at_offset(int depth, __isl_keep isl_aff *aff,
2314 int offset)
2316 aff = isl_aff_copy(aff);
2317 aff = isl_aff_add_coefficient_si(aff, isl_dim_in, depth, -1);
2318 aff = isl_aff_add_constant_si(aff, offset);
2319 return isl_equality_from_aff(aff);
2322 /* Update *user to the number of integer divsions in the first element
2323 * of "ma", if it is larger than the current value.
2325 static isl_stat update_n_div(__isl_take isl_set *set,
2326 __isl_take isl_multi_aff *ma, void *user)
2328 isl_aff *aff;
2329 int *n = user;
2330 int n_div;
2332 aff = isl_multi_aff_get_aff(ma, 0);
2333 n_div = isl_aff_dim(aff, isl_dim_div);
2334 isl_aff_free(aff);
2335 isl_multi_aff_free(ma);
2336 isl_set_free(set);
2338 if (n_div > *n)
2339 *n = n_div;
2341 return aff ? isl_stat_ok : isl_stat_error;
2344 /* Get the number of integer divisions in the expression for the iterator
2345 * value at the first slice in the unrolling based on lower bound "lower",
2346 * taking into account the expansion that needs to be performed on this slice.
2348 static int get_expanded_n_div(struct isl_find_unroll_data *data,
2349 __isl_keep isl_aff *lower)
2351 isl_constraint *c;
2352 isl_set *set;
2353 isl_map *it_map, *expansion;
2354 isl_pw_multi_aff *pma;
2355 int n;
2357 c = at_offset(data->depth, lower, 0);
2358 set = isl_set_copy(data->domain);
2359 set = isl_set_add_constraint(set, c);
2360 expansion = isl_map_from_basic_map(isl_basic_map_copy(data->expansion));
2361 set = isl_set_apply(set, expansion);
2362 it_map = isl_ast_build_map_to_iterator(data->build, set);
2363 pma = isl_pw_multi_aff_from_map(it_map);
2364 n = 0;
2365 if (isl_pw_multi_aff_foreach_piece(pma, &update_n_div, &n) < 0)
2366 n = -1;
2367 isl_pw_multi_aff_free(pma);
2369 return n;
2372 /* Is the lower bound "lower" with corresponding iteration count "n"
2373 * better than the one stored in "data"?
2374 * If there is no upper bound on the iteration count ("n" is infinity) or
2375 * if the count is too large, then we cannot use this lower bound.
2376 * Otherwise, if there was no previous lower bound or
2377 * if the iteration count of the new lower bound is smaller than
2378 * the iteration count of the previous lower bound, then we consider
2379 * the new lower bound to be better.
2380 * If the iteration count is the same, then compare the number
2381 * of integer divisions that would be needed to express
2382 * the iterator value at the first slice in the unrolling
2383 * according to the lower bound. If we end up computing this
2384 * number, then store the lowest value in data->n_div.
2386 static int is_better_lower_bound(struct isl_find_unroll_data *data,
2387 __isl_keep isl_aff *lower, __isl_keep isl_val *n)
2389 int cmp;
2390 int n_div;
2392 if (!n)
2393 return -1;
2394 if (isl_val_is_infty(n))
2395 return 0;
2396 if (isl_val_cmp_si(n, INT_MAX) > 0)
2397 return 0;
2398 if (!data->lower)
2399 return 1;
2400 cmp = isl_val_cmp_si(n, *data->n);
2401 if (cmp < 0)
2402 return 1;
2403 if (cmp > 0)
2404 return 0;
2405 if (data->n_div < 0)
2406 data->n_div = get_expanded_n_div(data, data->lower);
2407 if (data->n_div < 0)
2408 return -1;
2409 if (data->n_div == 0)
2410 return 0;
2411 n_div = get_expanded_n_div(data, lower);
2412 if (n_div < 0)
2413 return -1;
2414 if (n_div >= data->n_div)
2415 return 0;
2416 data->n_div = n_div;
2418 return 1;
2421 /* Check if we can use "c" as a lower bound and if it is better than
2422 * any previously found lower bound.
2424 * If "c" does not involve the dimension at the current depth,
2425 * then we cannot use it.
2426 * Otherwise, let "c" be of the form
2428 * i >= f(j)/a
2430 * We compute the maximal value of
2432 * -ceil(f(j)/a)) + i + 1
2434 * over the domain. If there is such a value "n", then we know
2436 * -ceil(f(j)/a)) + i + 1 <= n
2438 * or
2440 * i < ceil(f(j)/a)) + n
2442 * meaning that we can use ceil(f(j)/a)) as a lower bound for unrolling.
2443 * We just need to check if we have found any lower bound before and
2444 * if the new lower bound is better (smaller n or fewer integer divisions)
2445 * than the previously found lower bounds.
2447 static isl_stat update_unrolling_lower_bound(struct isl_find_unroll_data *data,
2448 __isl_keep isl_constraint *c)
2450 isl_aff *aff, *lower;
2451 isl_val *max;
2452 int better;
2454 if (!isl_constraint_is_lower_bound(c, isl_dim_set, data->depth))
2455 return isl_stat_ok;
2457 lower = isl_constraint_get_bound(c, isl_dim_set, data->depth);
2458 lower = isl_aff_ceil(lower);
2459 aff = isl_aff_copy(lower);
2460 aff = isl_aff_neg(aff);
2461 aff = isl_aff_add_coefficient_si(aff, isl_dim_in, data->depth, 1);
2462 aff = isl_aff_add_constant_si(aff, 1);
2463 max = isl_set_max_val(data->domain, aff);
2464 isl_aff_free(aff);
2466 better = is_better_lower_bound(data, lower, max);
2467 if (better < 0 || !better) {
2468 isl_val_free(max);
2469 isl_aff_free(lower);
2470 return better < 0 ? isl_stat_error : isl_stat_ok;
2473 isl_aff_free(data->lower);
2474 data->lower = lower;
2475 *data->n = isl_val_get_num_si(max);
2476 isl_val_free(max);
2478 return isl_stat_ok;
2481 /* Check if we can use "c" as a lower bound and if it is better than
2482 * any previously found lower bound.
2484 static isl_stat constraint_find_unroll(__isl_take isl_constraint *c, void *user)
2486 struct isl_find_unroll_data *data;
2487 isl_stat r;
2489 data = (struct isl_find_unroll_data *) user;
2490 r = update_unrolling_lower_bound(data, c);
2491 isl_constraint_free(c);
2493 return r;
2496 /* Look for a lower bound l(i) on the dimension at "depth"
2497 * and a size n such that "domain" is a subset of
2499 * { [i] : l(i) <= i_d < l(i) + n }
2501 * where d is "depth" and l(i) depends only on earlier dimensions.
2502 * Furthermore, try and find a lower bound such that n is as small as possible.
2503 * In particular, "n" needs to be finite.
2504 * "build" is the build in which the unrolling will be performed.
2505 * "expansion" is the expansion that needs to be applied to "domain"
2506 * in the unrolling that will be performed.
2508 * Inner dimensions have been eliminated from "domain" by the caller.
2510 * We first construct a collection of lower bounds on the input set
2511 * by computing its simple hull. We then iterate through them,
2512 * discarding those that we cannot use (either because they do not
2513 * involve the dimension at "depth" or because they have no corresponding
2514 * upper bound, meaning that "n" would be unbounded) and pick out the
2515 * best from the remaining ones.
2517 * If we cannot find a suitable lower bound, then we consider that
2518 * to be an error.
2520 static __isl_give isl_aff *find_unroll_lower_bound(
2521 __isl_keep isl_ast_build *build, __isl_keep isl_set *domain,
2522 int depth, __isl_keep isl_basic_map *expansion, int *n)
2524 struct isl_find_unroll_data data =
2525 { build, domain, depth, expansion, NULL, n, -1 };
2526 isl_basic_set *hull;
2528 hull = isl_set_simple_hull(isl_set_copy(domain));
2530 if (isl_basic_set_foreach_constraint(hull,
2531 &constraint_find_unroll, &data) < 0)
2532 goto error;
2534 isl_basic_set_free(hull);
2536 if (!data.lower)
2537 isl_die(isl_set_get_ctx(domain), isl_error_invalid,
2538 "cannot find lower bound for unrolling", return NULL);
2540 return data.lower;
2541 error:
2542 isl_basic_set_free(hull);
2543 return isl_aff_free(data.lower);
2546 /* Call "fn" on each iteration of the current dimension of "domain".
2547 * If "init" is not NULL, then it is called with the number of
2548 * iterations before any call to "fn".
2549 * Return -1 on failure.
2551 * Since we are going to be iterating over the individual values,
2552 * we first check if there are any strides on the current dimension.
2553 * If there is, we rewrite the current dimension i as
2555 * i = stride i' + offset
2557 * and then iterate over individual values of i' instead.
2559 * We then look for a lower bound on i' and a size such that the domain
2560 * is a subset of
2562 * { [j,i'] : l(j) <= i' < l(j) + n }
2564 * and then take slices of the domain at values of i'
2565 * between l(j) and l(j) + n - 1.
2567 * We compute the unshifted simple hull of each slice to ensure that
2568 * we have a single basic set per offset. The slicing constraint
2569 * may get simplified away before the unshifted simple hull is taken
2570 * and may therefore in some rare cases disappear from the result.
2571 * We therefore explicitly add the constraint back after computing
2572 * the unshifted simple hull to ensure that the basic sets
2573 * remain disjoint. The constraints that are dropped by taking the hull
2574 * will be taken into account at the next level, as in the case of the
2575 * atomic option.
2577 * Finally, we map i' back to i and call "fn".
2579 static int foreach_iteration(__isl_take isl_set *domain,
2580 __isl_keep isl_ast_build *build, int (*init)(int n, void *user),
2581 int (*fn)(__isl_take isl_basic_set *bset, void *user), void *user)
2583 int i, n;
2584 int empty;
2585 int depth;
2586 isl_multi_aff *expansion;
2587 isl_basic_map *bmap;
2588 isl_aff *lower = NULL;
2589 isl_ast_build *stride_build;
2591 depth = isl_ast_build_get_depth(build);
2593 domain = isl_ast_build_eliminate_inner(build, domain);
2594 domain = isl_set_intersect(domain, isl_ast_build_get_domain(build));
2595 stride_build = isl_ast_build_copy(build);
2596 stride_build = isl_ast_build_detect_strides(stride_build,
2597 isl_set_copy(domain));
2598 expansion = isl_ast_build_get_stride_expansion(stride_build);
2600 domain = isl_set_preimage_multi_aff(domain,
2601 isl_multi_aff_copy(expansion));
2602 domain = isl_ast_build_eliminate_divs(stride_build, domain);
2603 isl_ast_build_free(stride_build);
2605 bmap = isl_basic_map_from_multi_aff(expansion);
2607 empty = isl_set_is_empty(domain);
2608 if (empty < 0) {
2609 n = -1;
2610 } else if (empty) {
2611 n = 0;
2612 } else {
2613 lower = find_unroll_lower_bound(build, domain, depth, bmap, &n);
2614 if (!lower)
2615 n = -1;
2617 if (n >= 0 && init && init(n, user) < 0)
2618 n = -1;
2619 for (i = 0; i < n; ++i) {
2620 isl_set *set;
2621 isl_basic_set *bset;
2622 isl_constraint *slice;
2624 slice = at_offset(depth, lower, i);
2625 set = isl_set_copy(domain);
2626 set = isl_set_add_constraint(set, isl_constraint_copy(slice));
2627 bset = isl_set_unshifted_simple_hull(set);
2628 bset = isl_basic_set_add_constraint(bset, slice);
2629 bset = isl_basic_set_apply(bset, isl_basic_map_copy(bmap));
2631 if (fn(bset, user) < 0)
2632 break;
2635 isl_aff_free(lower);
2636 isl_set_free(domain);
2637 isl_basic_map_free(bmap);
2639 return n < 0 || i < n ? -1 : 0;
2642 /* Data structure for storing the results and the intermediate objects
2643 * of compute_domains.
2645 * "list" is the main result of the function and contains a list
2646 * of disjoint basic sets for which code should be generated.
2648 * "executed" and "build" are inputs to compute_domains.
2649 * "schedule_domain" is the domain of "executed".
2651 * "option" constains the domains at the current depth that should by
2652 * atomic, separated or unrolled. These domains are as specified by
2653 * the user, except that inner dimensions have been eliminated and
2654 * that they have been made pair-wise disjoint.
2656 * "sep_class" contains the user-specified split into separation classes
2657 * specialized to the current depth.
2658 * "done" contains the union of the separation domains that have already
2659 * been handled.
2661 struct isl_codegen_domains {
2662 isl_basic_set_list *list;
2664 isl_union_map *executed;
2665 isl_ast_build *build;
2666 isl_set *schedule_domain;
2668 isl_set *option[4];
2670 isl_map *sep_class;
2671 isl_set *done;
2674 /* Internal data structure for do_unroll.
2676 * "domains" stores the results of compute_domains.
2677 * "class_domain" is the original class domain passed to do_unroll.
2678 * "unroll_domain" collects the unrolled iterations.
2680 struct isl_ast_unroll_data {
2681 struct isl_codegen_domains *domains;
2682 isl_set *class_domain;
2683 isl_set *unroll_domain;
2686 /* Given an iteration of an unrolled domain represented by "bset",
2687 * add it to data->domains->list.
2688 * Since we may have dropped some constraints, we intersect with
2689 * the class domain again to ensure that each element in the list
2690 * is disjoint from the other class domains.
2692 static int do_unroll_iteration(__isl_take isl_basic_set *bset, void *user)
2694 struct isl_ast_unroll_data *data = user;
2695 isl_set *set;
2696 isl_basic_set_list *list;
2698 set = isl_set_from_basic_set(bset);
2699 data->unroll_domain = isl_set_union(data->unroll_domain,
2700 isl_set_copy(set));
2701 set = isl_set_intersect(set, isl_set_copy(data->class_domain));
2702 set = isl_set_make_disjoint(set);
2703 list = isl_basic_set_list_from_set(set);
2704 data->domains->list = isl_basic_set_list_concat(data->domains->list,
2705 list);
2707 return 0;
2710 /* Extend domains->list with a list of basic sets, one for each value
2711 * of the current dimension in "domain" and remove the corresponding
2712 * sets from the class domain. Return the updated class domain.
2713 * The divs that involve the current dimension have not been projected out
2714 * from this domain.
2716 * We call foreach_iteration to iterate over the individual values and
2717 * in do_unroll_iteration we collect the individual basic sets in
2718 * domains->list and their union in data->unroll_domain, which is then
2719 * used to update the class domain.
2721 static __isl_give isl_set *do_unroll(struct isl_codegen_domains *domains,
2722 __isl_take isl_set *domain, __isl_take isl_set *class_domain)
2724 struct isl_ast_unroll_data data;
2726 if (!domain)
2727 return isl_set_free(class_domain);
2728 if (!class_domain)
2729 return isl_set_free(domain);
2731 data.domains = domains;
2732 data.class_domain = class_domain;
2733 data.unroll_domain = isl_set_empty(isl_set_get_space(domain));
2735 if (foreach_iteration(domain, domains->build, NULL,
2736 &do_unroll_iteration, &data) < 0)
2737 data.unroll_domain = isl_set_free(data.unroll_domain);
2739 class_domain = isl_set_subtract(class_domain, data.unroll_domain);
2741 return class_domain;
2744 /* Add domains to domains->list for each individual value of the current
2745 * dimension, for that part of the schedule domain that lies in the
2746 * intersection of the option domain and the class domain.
2747 * Remove the corresponding sets from the class domain and
2748 * return the updated class domain.
2750 * We first break up the unroll option domain into individual pieces
2751 * and then handle each of them separately. The unroll option domain
2752 * has been made disjoint in compute_domains_init_options,
2754 * Note that we actively want to combine different pieces of the
2755 * schedule domain that have the same value at the current dimension.
2756 * We therefore need to break up the unroll option domain before
2757 * intersecting with class and schedule domain, hoping that the
2758 * unroll option domain specified by the user is relatively simple.
2760 static __isl_give isl_set *compute_unroll_domains(
2761 struct isl_codegen_domains *domains, __isl_take isl_set *class_domain)
2763 isl_set *unroll_domain;
2764 isl_basic_set_list *unroll_list;
2765 int i, n;
2766 int empty;
2768 empty = isl_set_is_empty(domains->option[isl_ast_loop_unroll]);
2769 if (empty < 0)
2770 return isl_set_free(class_domain);
2771 if (empty)
2772 return class_domain;
2774 unroll_domain = isl_set_copy(domains->option[isl_ast_loop_unroll]);
2775 unroll_list = isl_basic_set_list_from_set(unroll_domain);
2777 n = isl_basic_set_list_n_basic_set(unroll_list);
2778 for (i = 0; i < n; ++i) {
2779 isl_basic_set *bset;
2781 bset = isl_basic_set_list_get_basic_set(unroll_list, i);
2782 unroll_domain = isl_set_from_basic_set(bset);
2783 unroll_domain = isl_set_intersect(unroll_domain,
2784 isl_set_copy(class_domain));
2785 unroll_domain = isl_set_intersect(unroll_domain,
2786 isl_set_copy(domains->schedule_domain));
2788 empty = isl_set_is_empty(unroll_domain);
2789 if (empty >= 0 && empty) {
2790 isl_set_free(unroll_domain);
2791 continue;
2794 class_domain = do_unroll(domains, unroll_domain, class_domain);
2797 isl_basic_set_list_free(unroll_list);
2799 return class_domain;
2802 /* Try and construct a single basic set that includes the intersection of
2803 * the schedule domain, the atomic option domain and the class domain.
2804 * Add the resulting basic set(s) to domains->list and remove them
2805 * from class_domain. Return the updated class domain.
2807 * We construct a single domain rather than trying to combine
2808 * the schedule domains of individual domains because we are working
2809 * within a single component so that non-overlapping schedule domains
2810 * should already have been separated.
2811 * We do however need to make sure that this single domains is a subset
2812 * of the class domain so that it would not intersect with any other
2813 * class domains. This means that we may end up splitting up the atomic
2814 * domain in case separation classes are being used.
2816 * "domain" is the intersection of the schedule domain and the class domain,
2817 * with inner dimensions projected out.
2819 static __isl_give isl_set *compute_atomic_domain(
2820 struct isl_codegen_domains *domains, __isl_take isl_set *class_domain)
2822 isl_basic_set *bset;
2823 isl_basic_set_list *list;
2824 isl_set *domain, *atomic_domain;
2825 int empty;
2827 domain = isl_set_copy(domains->option[isl_ast_loop_atomic]);
2828 domain = isl_set_intersect(domain, isl_set_copy(class_domain));
2829 domain = isl_set_intersect(domain,
2830 isl_set_copy(domains->schedule_domain));
2831 empty = isl_set_is_empty(domain);
2832 if (empty < 0)
2833 class_domain = isl_set_free(class_domain);
2834 if (empty) {
2835 isl_set_free(domain);
2836 return class_domain;
2839 domain = isl_ast_build_eliminate(domains->build, domain);
2840 domain = isl_set_coalesce(domain);
2841 bset = isl_set_unshifted_simple_hull(domain);
2842 domain = isl_set_from_basic_set(bset);
2843 atomic_domain = isl_set_copy(domain);
2844 domain = isl_set_intersect(domain, isl_set_copy(class_domain));
2845 class_domain = isl_set_subtract(class_domain, atomic_domain);
2846 domain = isl_set_make_disjoint(domain);
2847 list = isl_basic_set_list_from_set(domain);
2848 domains->list = isl_basic_set_list_concat(domains->list, list);
2850 return class_domain;
2853 /* Split up the schedule domain into uniform basic sets,
2854 * in the sense that each element in a basic set is associated to
2855 * elements of the same domains, and add the result to domains->list.
2856 * Do this for that part of the schedule domain that lies in the
2857 * intersection of "class_domain" and the separate option domain.
2859 * "class_domain" may or may not include the constraints
2860 * of the schedule domain, but this does not make a difference
2861 * since we are going to intersect it with the domain of the inverse schedule.
2862 * If it includes schedule domain constraints, then they may involve
2863 * inner dimensions, but we will eliminate them in separation_domain.
2865 static int compute_separate_domain(struct isl_codegen_domains *domains,
2866 __isl_keep isl_set *class_domain)
2868 isl_space *space;
2869 isl_set *domain;
2870 isl_union_map *executed;
2871 isl_basic_set_list *list;
2872 int empty;
2874 domain = isl_set_copy(domains->option[isl_ast_loop_separate]);
2875 domain = isl_set_intersect(domain, isl_set_copy(class_domain));
2876 executed = isl_union_map_copy(domains->executed);
2877 executed = isl_union_map_intersect_domain(executed,
2878 isl_union_set_from_set(domain));
2879 empty = isl_union_map_is_empty(executed);
2880 if (empty < 0 || empty) {
2881 isl_union_map_free(executed);
2882 return empty < 0 ? -1 : 0;
2885 space = isl_set_get_space(class_domain);
2886 domain = separate_schedule_domains(space, executed, domains->build);
2888 list = isl_basic_set_list_from_set(domain);
2889 domains->list = isl_basic_set_list_concat(domains->list, list);
2891 return 0;
2894 /* Split up the domain at the current depth into disjoint
2895 * basic sets for which code should be generated separately
2896 * for the given separation class domain.
2898 * If any separation classes have been defined, then "class_domain"
2899 * is the domain of the current class and does not refer to inner dimensions.
2900 * Otherwise, "class_domain" is the universe domain.
2902 * We first make sure that the class domain is disjoint from
2903 * previously considered class domains.
2905 * The separate domains can be computed directly from the "class_domain".
2907 * The unroll, atomic and remainder domains need the constraints
2908 * from the schedule domain.
2910 * For unrolling, the actual schedule domain is needed (with divs that
2911 * may refer to the current dimension) so that stride detection can be
2912 * performed.
2914 * For atomic and remainder domains, inner dimensions and divs involving
2915 * the current dimensions should be eliminated.
2916 * In case we are working within a separation class, we need to intersect
2917 * the result with the current "class_domain" to ensure that the domains
2918 * are disjoint from those generated from other class domains.
2920 * The domain that has been made atomic may be larger than specified
2921 * by the user since it needs to be representable as a single basic set.
2922 * This possibly larger domain is removed from class_domain by
2923 * compute_atomic_domain. It is computed first so that the extended domain
2924 * would not overlap with any domains computed before.
2925 * Similary, the unrolled domains may have some constraints removed and
2926 * may therefore also be larger than specified by the user.
2928 * If anything is left after handling separate, unroll and atomic,
2929 * we split it up into basic sets and append the basic sets to domains->list.
2931 static isl_stat compute_partial_domains(struct isl_codegen_domains *domains,
2932 __isl_take isl_set *class_domain)
2934 isl_basic_set_list *list;
2935 isl_set *domain;
2937 class_domain = isl_set_subtract(class_domain,
2938 isl_set_copy(domains->done));
2939 domains->done = isl_set_union(domains->done,
2940 isl_set_copy(class_domain));
2942 class_domain = compute_atomic_domain(domains, class_domain);
2943 class_domain = compute_unroll_domains(domains, class_domain);
2945 domain = isl_set_copy(class_domain);
2947 if (compute_separate_domain(domains, domain) < 0)
2948 goto error;
2949 domain = isl_set_subtract(domain,
2950 isl_set_copy(domains->option[isl_ast_loop_separate]));
2952 domain = isl_set_intersect(domain,
2953 isl_set_copy(domains->schedule_domain));
2955 domain = isl_ast_build_eliminate(domains->build, domain);
2956 domain = isl_set_intersect(domain, isl_set_copy(class_domain));
2958 domain = isl_set_coalesce(domain);
2959 domain = isl_set_make_disjoint(domain);
2961 list = isl_basic_set_list_from_set(domain);
2962 domains->list = isl_basic_set_list_concat(domains->list, list);
2964 isl_set_free(class_domain);
2966 return isl_stat_ok;
2967 error:
2968 isl_set_free(domain);
2969 isl_set_free(class_domain);
2970 return isl_stat_error;
2973 /* Split up the domain at the current depth into disjoint
2974 * basic sets for which code should be generated separately
2975 * for the separation class identified by "pnt".
2977 * We extract the corresponding class domain from domains->sep_class,
2978 * eliminate inner dimensions and pass control to compute_partial_domains.
2980 static isl_stat compute_class_domains(__isl_take isl_point *pnt, void *user)
2982 struct isl_codegen_domains *domains = user;
2983 isl_set *class_set;
2984 isl_set *domain;
2985 int disjoint;
2987 class_set = isl_set_from_point(pnt);
2988 domain = isl_map_domain(isl_map_intersect_range(
2989 isl_map_copy(domains->sep_class), class_set));
2990 domain = isl_ast_build_compute_gist(domains->build, domain);
2991 domain = isl_ast_build_eliminate(domains->build, domain);
2993 disjoint = isl_set_plain_is_disjoint(domain, domains->schedule_domain);
2994 if (disjoint < 0)
2995 return isl_stat_error;
2996 if (disjoint) {
2997 isl_set_free(domain);
2998 return isl_stat_ok;
3001 return compute_partial_domains(domains, domain);
3004 /* Extract the domains at the current depth that should be atomic,
3005 * separated or unrolled and store them in option.
3007 * The domains specified by the user might overlap, so we make
3008 * them disjoint by subtracting earlier domains from later domains.
3010 static void compute_domains_init_options(isl_set *option[4],
3011 __isl_keep isl_ast_build *build)
3013 enum isl_ast_loop_type type, type2;
3014 isl_set *unroll;
3016 for (type = isl_ast_loop_atomic;
3017 type <= isl_ast_loop_separate; ++type) {
3018 option[type] = isl_ast_build_get_option_domain(build, type);
3019 for (type2 = isl_ast_loop_atomic; type2 < type; ++type2)
3020 option[type] = isl_set_subtract(option[type],
3021 isl_set_copy(option[type2]));
3024 unroll = option[isl_ast_loop_unroll];
3025 unroll = isl_set_coalesce(unroll);
3026 unroll = isl_set_make_disjoint(unroll);
3027 option[isl_ast_loop_unroll] = unroll;
3030 /* Split up the domain at the current depth into disjoint
3031 * basic sets for which code should be generated separately,
3032 * based on the user-specified options.
3033 * Return the list of disjoint basic sets.
3035 * There are three kinds of domains that we need to keep track of.
3036 * - the "schedule domain" is the domain of "executed"
3037 * - the "class domain" is the domain corresponding to the currrent
3038 * separation class
3039 * - the "option domain" is the domain corresponding to one of the options
3040 * atomic, unroll or separate
3042 * We first consider the individial values of the separation classes
3043 * and split up the domain for each of them separately.
3044 * Finally, we consider the remainder. If no separation classes were
3045 * specified, then we call compute_partial_domains with the universe
3046 * "class_domain". Otherwise, we take the "schedule_domain" as "class_domain",
3047 * with inner dimensions removed. We do this because we want to
3048 * avoid computing the complement of the class domains (i.e., the difference
3049 * between the universe and domains->done).
3051 static __isl_give isl_basic_set_list *compute_domains(
3052 __isl_keep isl_union_map *executed, __isl_keep isl_ast_build *build)
3054 struct isl_codegen_domains domains;
3055 isl_ctx *ctx;
3056 isl_set *domain;
3057 isl_union_set *schedule_domain;
3058 isl_set *classes;
3059 isl_space *space;
3060 int n_param;
3061 enum isl_ast_loop_type type;
3062 int empty;
3064 if (!executed)
3065 return NULL;
3067 ctx = isl_union_map_get_ctx(executed);
3068 domains.list = isl_basic_set_list_alloc(ctx, 0);
3070 schedule_domain = isl_union_map_domain(isl_union_map_copy(executed));
3071 domain = isl_set_from_union_set(schedule_domain);
3073 compute_domains_init_options(domains.option, build);
3075 domains.sep_class = isl_ast_build_get_separation_class(build);
3076 classes = isl_map_range(isl_map_copy(domains.sep_class));
3077 n_param = isl_set_dim(classes, isl_dim_param);
3078 classes = isl_set_project_out(classes, isl_dim_param, 0, n_param);
3080 space = isl_set_get_space(domain);
3081 domains.build = build;
3082 domains.schedule_domain = isl_set_copy(domain);
3083 domains.executed = executed;
3084 domains.done = isl_set_empty(space);
3086 if (isl_set_foreach_point(classes, &compute_class_domains, &domains) < 0)
3087 domains.list = isl_basic_set_list_free(domains.list);
3088 isl_set_free(classes);
3090 empty = isl_set_is_empty(domains.done);
3091 if (empty < 0) {
3092 domains.list = isl_basic_set_list_free(domains.list);
3093 domain = isl_set_free(domain);
3094 } else if (empty) {
3095 isl_set_free(domain);
3096 domain = isl_set_universe(isl_set_get_space(domains.done));
3097 } else {
3098 domain = isl_ast_build_eliminate(build, domain);
3100 if (compute_partial_domains(&domains, domain) < 0)
3101 domains.list = isl_basic_set_list_free(domains.list);
3103 isl_set_free(domains.schedule_domain);
3104 isl_set_free(domains.done);
3105 isl_map_free(domains.sep_class);
3106 for (type = isl_ast_loop_atomic; type <= isl_ast_loop_separate; ++type)
3107 isl_set_free(domains.option[type]);
3109 return domains.list;
3112 /* Generate code for a single component, after shifting (if any)
3113 * has been applied, in case the schedule was specified as a union map.
3115 * We first split up the domain at the current depth into disjoint
3116 * basic sets based on the user-specified options.
3117 * Then we generated code for each of them and concatenate the results.
3119 static __isl_give isl_ast_graft_list *generate_shifted_component_flat(
3120 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build)
3122 isl_basic_set_list *domain_list;
3123 isl_ast_graft_list *list = NULL;
3125 domain_list = compute_domains(executed, build);
3126 list = generate_parallel_domains(domain_list, executed, build);
3128 isl_basic_set_list_free(domain_list);
3129 isl_union_map_free(executed);
3130 isl_ast_build_free(build);
3132 return list;
3135 /* Generate code for a single component, after shifting (if any)
3136 * has been applied, in case the schedule was specified as a schedule tree
3137 * and the separate option was specified.
3139 * We perform separation on the domain of "executed" and then generate
3140 * an AST for each of the resulting disjoint basic sets.
3142 static __isl_give isl_ast_graft_list *generate_shifted_component_tree_separate(
3143 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build)
3145 isl_space *space;
3146 isl_set *domain;
3147 isl_basic_set_list *domain_list;
3148 isl_ast_graft_list *list;
3150 space = isl_ast_build_get_space(build, 1);
3151 domain = separate_schedule_domains(space,
3152 isl_union_map_copy(executed), build);
3153 domain_list = isl_basic_set_list_from_set(domain);
3155 list = generate_parallel_domains(domain_list, executed, build);
3157 isl_basic_set_list_free(domain_list);
3158 isl_union_map_free(executed);
3159 isl_ast_build_free(build);
3161 return list;
3164 /* Internal data structure for generate_shifted_component_tree_unroll.
3166 * "executed" and "build" are inputs to generate_shifted_component_tree_unroll.
3167 * "list" collects the constructs grafts.
3169 struct isl_ast_unroll_tree_data {
3170 isl_union_map *executed;
3171 isl_ast_build *build;
3172 isl_ast_graft_list *list;
3175 /* Initialize data->list to a list of "n" elements.
3177 static int init_unroll_tree(int n, void *user)
3179 struct isl_ast_unroll_tree_data *data = user;
3180 isl_ctx *ctx;
3182 ctx = isl_ast_build_get_ctx(data->build);
3183 data->list = isl_ast_graft_list_alloc(ctx, n);
3185 return 0;
3188 /* Given an iteration of an unrolled domain represented by "bset",
3189 * generate the corresponding AST and add the result to data->list.
3191 static int do_unroll_tree_iteration(__isl_take isl_basic_set *bset, void *user)
3193 struct isl_ast_unroll_tree_data *data = user;
3195 data->list = add_node(data->list, isl_union_map_copy(data->executed),
3196 bset, isl_ast_build_copy(data->build));
3198 return 0;
3201 /* Generate code for a single component, after shifting (if any)
3202 * has been applied, in case the schedule was specified as a schedule tree
3203 * and the unroll option was specified.
3205 * We call foreach_iteration to iterate over the individual values and
3206 * construct and collect the corresponding grafts in do_unroll_tree_iteration.
3208 static __isl_give isl_ast_graft_list *generate_shifted_component_tree_unroll(
3209 __isl_take isl_union_map *executed, __isl_take isl_set *domain,
3210 __isl_take isl_ast_build *build)
3212 struct isl_ast_unroll_tree_data data = { executed, build, NULL };
3214 if (foreach_iteration(domain, build, &init_unroll_tree,
3215 &do_unroll_tree_iteration, &data) < 0)
3216 data.list = isl_ast_graft_list_free(data.list);
3218 isl_union_map_free(executed);
3219 isl_ast_build_free(build);
3221 return data.list;
3224 /* Generate code for a single component, after shifting (if any)
3225 * has been applied, in case the schedule was specified as a schedule tree.
3226 * In particular, handle the base case where there is either no isolated
3227 * set or we are within the isolated set (in which case "isolated" is set)
3228 * or the iterations that precede or follow the isolated set.
3230 * The schedule domain is broken up or combined into basic sets
3231 * according to the AST generation option specified in the current
3232 * schedule node, which may be either atomic, separate, unroll or
3233 * unspecified. If the option is unspecified, then we currently simply
3234 * split the schedule domain into disjoint basic sets.
3236 * In case the separate option is specified, the AST generation is
3237 * handled by generate_shifted_component_tree_separate.
3238 * In the other cases, we need the global schedule domain.
3239 * In the unroll case, the AST generation is then handled by
3240 * generate_shifted_component_tree_unroll which needs the actual
3241 * schedule domain (with divs that may refer to the current dimension)
3242 * so that stride detection can be performed.
3243 * In the atomic or unspecified case, inner dimensions and divs involving
3244 * the current dimensions should be eliminated.
3245 * The result is then either combined into a single basic set or
3246 * split up into disjoint basic sets.
3247 * Finally an AST is generated for each basic set and the results are
3248 * concatenated.
3250 static __isl_give isl_ast_graft_list *generate_shifted_component_tree_base(
3251 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build,
3252 int isolated)
3254 isl_union_set *schedule_domain;
3255 isl_set *domain;
3256 isl_basic_set_list *domain_list;
3257 isl_ast_graft_list *list;
3258 enum isl_ast_loop_type type;
3260 type = isl_ast_build_get_loop_type(build, isolated);
3261 if (type < 0)
3262 goto error;
3264 if (type == isl_ast_loop_separate)
3265 return generate_shifted_component_tree_separate(executed,
3266 build);
3268 schedule_domain = isl_union_map_domain(isl_union_map_copy(executed));
3269 domain = isl_set_from_union_set(schedule_domain);
3271 if (type == isl_ast_loop_unroll)
3272 return generate_shifted_component_tree_unroll(executed, domain,
3273 build);
3275 domain = isl_ast_build_eliminate(build, domain);
3276 domain = isl_set_coalesce(domain);
3278 if (type == isl_ast_loop_atomic) {
3279 isl_basic_set *hull;
3280 hull = isl_set_unshifted_simple_hull(domain);
3281 domain_list = isl_basic_set_list_from_basic_set(hull);
3282 } else {
3283 domain = isl_set_make_disjoint(domain);
3284 domain_list = isl_basic_set_list_from_set(domain);
3287 list = generate_parallel_domains(domain_list, executed, build);
3289 isl_basic_set_list_free(domain_list);
3290 isl_union_map_free(executed);
3291 isl_ast_build_free(build);
3293 return list;
3294 error:
3295 isl_union_map_free(executed);
3296 isl_ast_build_free(build);
3297 return NULL;
3300 /* Extract out the disjunction imposed by "domain" on the outer
3301 * schedule dimensions.
3303 * In particular, remove all inner dimensions from "domain" (including
3304 * the current dimension) and then remove the constraints that are shared
3305 * by all disjuncts in the result.
3307 static __isl_give isl_set *extract_disjunction(__isl_take isl_set *domain,
3308 __isl_keep isl_ast_build *build)
3310 isl_set *hull;
3311 int depth, dim;
3313 domain = isl_ast_build_specialize(build, domain);
3314 depth = isl_ast_build_get_depth(build);
3315 dim = isl_set_dim(domain, isl_dim_set);
3316 domain = isl_set_eliminate(domain, isl_dim_set, depth, dim - depth);
3317 domain = isl_set_remove_unknown_divs(domain);
3318 hull = isl_set_copy(domain);
3319 hull = isl_set_from_basic_set(isl_set_unshifted_simple_hull(hull));
3320 domain = isl_set_gist(domain, hull);
3322 return domain;
3325 /* Add "guard" to the grafts in "list".
3326 * "build" is the outer AST build, while "sub_build" includes "guard"
3327 * in its generated domain.
3329 * First combine the grafts into a single graft and then add the guard.
3330 * If the list is empty, or if some error occurred, then simply return
3331 * the list.
3333 static __isl_give isl_ast_graft_list *list_add_guard(
3334 __isl_take isl_ast_graft_list *list, __isl_keep isl_set *guard,
3335 __isl_keep isl_ast_build *build, __isl_keep isl_ast_build *sub_build)
3337 isl_ast_graft *graft;
3339 list = isl_ast_graft_list_fuse(list, sub_build);
3341 if (isl_ast_graft_list_n_ast_graft(list) != 1)
3342 return list;
3344 graft = isl_ast_graft_list_get_ast_graft(list, 0);
3345 graft = isl_ast_graft_add_guard(graft, isl_set_copy(guard), build);
3346 list = isl_ast_graft_list_set_ast_graft(list, 0, graft);
3348 return list;
3351 /* Generate code for a single component, after shifting (if any)
3352 * has been applied, in case the schedule was specified as a schedule tree.
3353 * In particular, do so for the specified subset of the schedule domain.
3355 * If we are outside of the isolated part, then "domain" may include
3356 * a disjunction. Explicitly generate this disjunction at this point
3357 * instead of relying on the disjunction getting hoisted back up
3358 * to this level.
3360 static __isl_give isl_ast_graft_list *generate_shifted_component_tree_part(
3361 __isl_keep isl_union_map *executed, __isl_take isl_set *domain,
3362 __isl_keep isl_ast_build *build, int isolated)
3364 isl_union_set *uset;
3365 isl_ast_graft_list *list;
3366 isl_ast_build *sub_build;
3367 int empty;
3369 uset = isl_union_set_from_set(isl_set_copy(domain));
3370 executed = isl_union_map_copy(executed);
3371 executed = isl_union_map_intersect_domain(executed, uset);
3372 empty = isl_union_map_is_empty(executed);
3373 if (empty < 0)
3374 goto error;
3375 if (empty) {
3376 isl_ctx *ctx;
3377 isl_union_map_free(executed);
3378 isl_set_free(domain);
3379 ctx = isl_ast_build_get_ctx(build);
3380 return isl_ast_graft_list_alloc(ctx, 0);
3383 sub_build = isl_ast_build_copy(build);
3384 if (!isolated) {
3385 domain = extract_disjunction(domain, build);
3386 sub_build = isl_ast_build_restrict_generated(sub_build,
3387 isl_set_copy(domain));
3389 list = generate_shifted_component_tree_base(executed,
3390 isl_ast_build_copy(sub_build), isolated);
3391 if (!isolated)
3392 list = list_add_guard(list, domain, build, sub_build);
3393 isl_ast_build_free(sub_build);
3394 isl_set_free(domain);
3395 return list;
3396 error:
3397 isl_union_map_free(executed);
3398 isl_set_free(domain);
3399 return NULL;
3402 /* Generate code for a single component, after shifting (if any)
3403 * has been applied, in case the schedule was specified as a schedule tree.
3404 * In particular, do so for the specified sequence of subsets
3405 * of the schedule domain, "before", "isolated", "after" and "other",
3406 * where only the "isolated" part is considered to be isolated.
3408 static __isl_give isl_ast_graft_list *generate_shifted_component_parts(
3409 __isl_take isl_union_map *executed, __isl_take isl_set *before,
3410 __isl_take isl_set *isolated, __isl_take isl_set *after,
3411 __isl_take isl_set *other, __isl_take isl_ast_build *build)
3413 isl_ast_graft_list *list, *res;
3415 res = generate_shifted_component_tree_part(executed, before, build, 0);
3416 list = generate_shifted_component_tree_part(executed, isolated,
3417 build, 1);
3418 res = isl_ast_graft_list_concat(res, list);
3419 list = generate_shifted_component_tree_part(executed, after, build, 0);
3420 res = isl_ast_graft_list_concat(res, list);
3421 list = generate_shifted_component_tree_part(executed, other, build, 0);
3422 res = isl_ast_graft_list_concat(res, list);
3424 isl_union_map_free(executed);
3425 isl_ast_build_free(build);
3427 return res;
3430 /* Does "set" intersect "first", but not "second"?
3432 static isl_bool only_intersects_first(__isl_keep isl_set *set,
3433 __isl_keep isl_set *first, __isl_keep isl_set *second)
3435 isl_bool disjoint;
3437 disjoint = isl_set_is_disjoint(set, first);
3438 if (disjoint < 0)
3439 return isl_bool_error;
3440 if (disjoint)
3441 return isl_bool_false;
3443 return isl_set_is_disjoint(set, second);
3446 /* Generate code for a single component, after shifting (if any)
3447 * has been applied, in case the schedule was specified as a schedule tree.
3448 * In particular, do so in case of isolation where there is
3449 * only an "isolated" part and an "after" part.
3450 * "dead1" and "dead2" are freed by this function in order to simplify
3451 * the caller.
3453 * The "before" and "other" parts are set to empty sets.
3455 static __isl_give isl_ast_graft_list *generate_shifted_component_only_after(
3456 __isl_take isl_union_map *executed, __isl_take isl_set *isolated,
3457 __isl_take isl_set *after, __isl_take isl_ast_build *build,
3458 __isl_take isl_set *dead1, __isl_take isl_set *dead2)
3460 isl_set *empty;
3462 empty = isl_set_empty(isl_set_get_space(after));
3463 isl_set_free(dead1);
3464 isl_set_free(dead2);
3465 return generate_shifted_component_parts(executed, isl_set_copy(empty),
3466 isolated, after, empty, build);
3469 /* Generate code for a single component, after shifting (if any)
3470 * has been applied, in case the schedule was specified as a schedule tree.
3472 * We first check if the user has specified an isolated schedule domain
3473 * and that we are not already outside of this isolated schedule domain.
3474 * If so, we break up the schedule domain into iterations that
3475 * precede the isolated domain, the isolated domain itself,
3476 * the iterations that follow the isolated domain and
3477 * the remaining iterations (those that are incomparable
3478 * to the isolated domain).
3479 * We generate an AST for each piece and concatenate the results.
3481 * In the special case where at least one element of the schedule
3482 * domain that does not belong to the isolated domain needs
3483 * to be scheduled after this isolated domain, but none of those
3484 * elements need to be scheduled before, break up the schedule domain
3485 * in only two parts, the isolated domain, and a part that will be
3486 * scheduled after the isolated domain.
3488 * If no isolated set has been specified, then we generate an
3489 * AST for the entire inverse schedule.
3491 static __isl_give isl_ast_graft_list *generate_shifted_component_tree(
3492 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build)
3494 int i, depth;
3495 int empty, has_isolate;
3496 isl_space *space;
3497 isl_union_set *schedule_domain;
3498 isl_set *domain;
3499 isl_basic_set *hull;
3500 isl_set *isolated, *before, *after, *test;
3501 isl_map *gt, *lt;
3502 isl_bool pure;
3504 build = isl_ast_build_extract_isolated(build);
3505 has_isolate = isl_ast_build_has_isolated(build);
3506 if (has_isolate < 0)
3507 executed = isl_union_map_free(executed);
3508 else if (!has_isolate)
3509 return generate_shifted_component_tree_base(executed, build, 0);
3511 schedule_domain = isl_union_map_domain(isl_union_map_copy(executed));
3512 domain = isl_set_from_union_set(schedule_domain);
3514 isolated = isl_ast_build_get_isolated(build);
3515 isolated = isl_set_intersect(isolated, isl_set_copy(domain));
3516 test = isl_ast_build_specialize(build, isl_set_copy(isolated));
3517 empty = isl_set_is_empty(test);
3518 isl_set_free(test);
3519 if (empty < 0)
3520 goto error;
3521 if (empty) {
3522 isl_set_free(isolated);
3523 isl_set_free(domain);
3524 return generate_shifted_component_tree_base(executed, build, 0);
3526 isolated = isl_ast_build_eliminate(build, isolated);
3527 hull = isl_set_unshifted_simple_hull(isolated);
3528 isolated = isl_set_from_basic_set(hull);
3530 depth = isl_ast_build_get_depth(build);
3531 space = isl_space_map_from_set(isl_set_get_space(isolated));
3532 gt = isl_map_universe(space);
3533 for (i = 0; i < depth; ++i)
3534 gt = isl_map_equate(gt, isl_dim_in, i, isl_dim_out, i);
3535 gt = isl_map_order_gt(gt, isl_dim_in, depth, isl_dim_out, depth);
3536 lt = isl_map_reverse(isl_map_copy(gt));
3537 before = isl_set_apply(isl_set_copy(isolated), gt);
3538 after = isl_set_apply(isl_set_copy(isolated), lt);
3540 domain = isl_set_subtract(domain, isl_set_copy(isolated));
3541 pure = only_intersects_first(domain, after, before);
3542 if (pure < 0)
3543 executed = isl_union_map_free(executed);
3544 else if (pure)
3545 return generate_shifted_component_only_after(executed, isolated,
3546 domain, build, before, after);
3547 domain = isl_set_subtract(domain, isl_set_copy(before));
3548 domain = isl_set_subtract(domain, isl_set_copy(after));
3549 after = isl_set_subtract(after, isl_set_copy(isolated));
3550 after = isl_set_subtract(after, isl_set_copy(before));
3551 before = isl_set_subtract(before, isl_set_copy(isolated));
3553 return generate_shifted_component_parts(executed, before, isolated,
3554 after, domain, build);
3555 error:
3556 isl_set_free(domain);
3557 isl_set_free(isolated);
3558 isl_union_map_free(executed);
3559 isl_ast_build_free(build);
3560 return NULL;
3563 /* Generate code for a single component, after shifting (if any)
3564 * has been applied.
3566 * Call generate_shifted_component_tree or generate_shifted_component_flat
3567 * depending on whether the schedule was specified as a schedule tree.
3569 static __isl_give isl_ast_graft_list *generate_shifted_component(
3570 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build)
3572 if (isl_ast_build_has_schedule_node(build))
3573 return generate_shifted_component_tree(executed, build);
3574 else
3575 return generate_shifted_component_flat(executed, build);
3578 struct isl_set_map_pair {
3579 isl_set *set;
3580 isl_map *map;
3583 /* Given an array "domain" of isl_set_map_pairs and an array "order"
3584 * of indices into the "domain" array,
3585 * return the union of the "map" fields of the elements
3586 * indexed by the first "n" elements of "order".
3588 static __isl_give isl_union_map *construct_component_executed(
3589 struct isl_set_map_pair *domain, int *order, int n)
3591 int i;
3592 isl_map *map;
3593 isl_union_map *executed;
3595 map = isl_map_copy(domain[order[0]].map);
3596 executed = isl_union_map_from_map(map);
3597 for (i = 1; i < n; ++i) {
3598 map = isl_map_copy(domain[order[i]].map);
3599 executed = isl_union_map_add_map(executed, map);
3602 return executed;
3605 /* Generate code for a single component, after shifting (if any)
3606 * has been applied.
3608 * The component inverse schedule is specified as the "map" fields
3609 * of the elements of "domain" indexed by the first "n" elements of "order".
3611 static __isl_give isl_ast_graft_list *generate_shifted_component_from_list(
3612 struct isl_set_map_pair *domain, int *order, int n,
3613 __isl_take isl_ast_build *build)
3615 isl_union_map *executed;
3617 executed = construct_component_executed(domain, order, n);
3618 return generate_shifted_component(executed, build);
3621 /* Does set dimension "pos" of "set" have an obviously fixed value?
3623 static int dim_is_fixed(__isl_keep isl_set *set, int pos)
3625 int fixed;
3626 isl_val *v;
3628 v = isl_set_plain_get_val_if_fixed(set, isl_dim_set, pos);
3629 if (!v)
3630 return -1;
3631 fixed = !isl_val_is_nan(v);
3632 isl_val_free(v);
3634 return fixed;
3637 /* Given an array "domain" of isl_set_map_pairs and an array "order"
3638 * of indices into the "domain" array,
3639 * do all (except for at most one) of the "set" field of the elements
3640 * indexed by the first "n" elements of "order" have a fixed value
3641 * at position "depth"?
3643 static int at_most_one_non_fixed(struct isl_set_map_pair *domain,
3644 int *order, int n, int depth)
3646 int i;
3647 int non_fixed = -1;
3649 for (i = 0; i < n; ++i) {
3650 int f;
3652 f = dim_is_fixed(domain[order[i]].set, depth);
3653 if (f < 0)
3654 return -1;
3655 if (f)
3656 continue;
3657 if (non_fixed >= 0)
3658 return 0;
3659 non_fixed = i;
3662 return 1;
3665 /* Given an array "domain" of isl_set_map_pairs and an array "order"
3666 * of indices into the "domain" array,
3667 * eliminate the inner dimensions from the "set" field of the elements
3668 * indexed by the first "n" elements of "order", provided the current
3669 * dimension does not have a fixed value.
3671 * Return the index of the first element in "order" with a corresponding
3672 * "set" field that does not have an (obviously) fixed value.
3674 static int eliminate_non_fixed(struct isl_set_map_pair *domain,
3675 int *order, int n, int depth, __isl_keep isl_ast_build *build)
3677 int i;
3678 int base = -1;
3680 for (i = n - 1; i >= 0; --i) {
3681 int f;
3682 f = dim_is_fixed(domain[order[i]].set, depth);
3683 if (f < 0)
3684 return -1;
3685 if (f)
3686 continue;
3687 domain[order[i]].set = isl_ast_build_eliminate_inner(build,
3688 domain[order[i]].set);
3689 base = i;
3692 return base;
3695 /* Given an array "domain" of isl_set_map_pairs and an array "order"
3696 * of indices into the "domain" array,
3697 * find the element of "domain" (amongst those indexed by the first "n"
3698 * elements of "order") with the "set" field that has the smallest
3699 * value for the current iterator.
3701 * Note that the domain with the smallest value may depend on the parameters
3702 * and/or outer loop dimension. Since the result of this function is only
3703 * used as heuristic, we only make a reasonable attempt at finding the best
3704 * domain, one that should work in case a single domain provides the smallest
3705 * value for the current dimension over all values of the parameters
3706 * and outer dimensions.
3708 * In particular, we compute the smallest value of the first domain
3709 * and replace it by that of any later domain if that later domain
3710 * has a smallest value that is smaller for at least some value
3711 * of the parameters and outer dimensions.
3713 static int first_offset(struct isl_set_map_pair *domain, int *order, int n,
3714 __isl_keep isl_ast_build *build)
3716 int i;
3717 isl_map *min_first;
3718 int first = 0;
3720 min_first = isl_ast_build_map_to_iterator(build,
3721 isl_set_copy(domain[order[0]].set));
3722 min_first = isl_map_lexmin(min_first);
3724 for (i = 1; i < n; ++i) {
3725 isl_map *min, *test;
3726 int empty;
3728 min = isl_ast_build_map_to_iterator(build,
3729 isl_set_copy(domain[order[i]].set));
3730 min = isl_map_lexmin(min);
3731 test = isl_map_copy(min);
3732 test = isl_map_apply_domain(isl_map_copy(min_first), test);
3733 test = isl_map_order_lt(test, isl_dim_in, 0, isl_dim_out, 0);
3734 empty = isl_map_is_empty(test);
3735 isl_map_free(test);
3736 if (empty >= 0 && !empty) {
3737 isl_map_free(min_first);
3738 first = i;
3739 min_first = min;
3740 } else
3741 isl_map_free(min);
3743 if (empty < 0)
3744 break;
3747 isl_map_free(min_first);
3749 return i < n ? -1 : first;
3752 /* Construct a shifted inverse schedule based on the original inverse schedule,
3753 * the stride and the offset.
3755 * The original inverse schedule is specified as the "map" fields
3756 * of the elements of "domain" indexed by the first "n" elements of "order".
3758 * "stride" and "offset" are such that the difference
3759 * between the values of the current dimension of domain "i"
3760 * and the values of the current dimension for some reference domain are
3761 * equal to
3763 * stride * integer + offset[i]
3765 * Moreover, 0 <= offset[i] < stride.
3767 * For each domain, we create a map
3769 * { [..., j, ...] -> [..., j - offset[i], offset[i], ....] }
3771 * where j refers to the current dimension and the other dimensions are
3772 * unchanged, and apply this map to the original schedule domain.
3774 * For example, for the original schedule
3776 * { A[i] -> [2i]: 0 <= i < 10; B[i] -> [2i+1] : 0 <= i < 10 }
3778 * and assuming the offset is 0 for the A domain and 1 for the B domain,
3779 * we apply the mapping
3781 * { [j] -> [j, 0] }
3783 * to the schedule of the "A" domain and the mapping
3785 * { [j - 1] -> [j, 1] }
3787 * to the schedule of the "B" domain.
3790 * Note that after the transformation, the differences between pairs
3791 * of values of the current dimension over all domains are multiples
3792 * of stride and that we have therefore exposed the stride.
3795 * To see that the mapping preserves the lexicographic order,
3796 * first note that each of the individual maps above preserves the order.
3797 * If the value of the current iterator is j1 in one domain and j2 in another,
3798 * then if j1 = j2, we know that the same map is applied to both domains
3799 * and the order is preserved.
3800 * Otherwise, let us assume, without loss of generality, that j1 < j2.
3801 * If c1 >= c2 (with c1 and c2 the corresponding offsets), then
3803 * j1 - c1 < j2 - c2
3805 * and the order is preserved.
3806 * If c1 < c2, then we know
3808 * 0 <= c2 - c1 < s
3810 * We also have
3812 * j2 - j1 = n * s + r
3814 * with n >= 0 and 0 <= r < s.
3815 * In other words, r = c2 - c1.
3816 * If n > 0, then
3818 * j1 - c1 < j2 - c2
3820 * If n = 0, then
3822 * j1 - c1 = j2 - c2
3824 * and so
3826 * (j1 - c1, c1) << (j2 - c2, c2)
3828 * with "<<" the lexicographic order, proving that the order is preserved
3829 * in all cases.
3831 static __isl_give isl_union_map *contruct_shifted_executed(
3832 struct isl_set_map_pair *domain, int *order, int n,
3833 __isl_keep isl_val *stride, __isl_keep isl_multi_val *offset,
3834 __isl_take isl_ast_build *build)
3836 int i;
3837 isl_union_map *executed;
3838 isl_space *space;
3839 isl_map *map;
3840 int depth;
3841 isl_constraint *c;
3843 depth = isl_ast_build_get_depth(build);
3844 space = isl_ast_build_get_space(build, 1);
3845 executed = isl_union_map_empty(isl_space_copy(space));
3846 space = isl_space_map_from_set(space);
3847 map = isl_map_identity(isl_space_copy(space));
3848 map = isl_map_eliminate(map, isl_dim_out, depth, 1);
3849 map = isl_map_insert_dims(map, isl_dim_out, depth + 1, 1);
3850 space = isl_space_insert_dims(space, isl_dim_out, depth + 1, 1);
3852 c = isl_constraint_alloc_equality(isl_local_space_from_space(space));
3853 c = isl_constraint_set_coefficient_si(c, isl_dim_in, depth, 1);
3854 c = isl_constraint_set_coefficient_si(c, isl_dim_out, depth, -1);
3856 for (i = 0; i < n; ++i) {
3857 isl_map *map_i;
3858 isl_val *v;
3860 v = isl_multi_val_get_val(offset, i);
3861 if (!v)
3862 break;
3863 map_i = isl_map_copy(map);
3864 map_i = isl_map_fix_val(map_i, isl_dim_out, depth + 1,
3865 isl_val_copy(v));
3866 v = isl_val_neg(v);
3867 c = isl_constraint_set_constant_val(c, v);
3868 map_i = isl_map_add_constraint(map_i, isl_constraint_copy(c));
3870 map_i = isl_map_apply_domain(isl_map_copy(domain[order[i]].map),
3871 map_i);
3872 executed = isl_union_map_add_map(executed, map_i);
3875 isl_constraint_free(c);
3876 isl_map_free(map);
3878 if (i < n)
3879 executed = isl_union_map_free(executed);
3881 return executed;
3884 /* Generate code for a single component, after exposing the stride,
3885 * given that the schedule domain is "shifted strided".
3887 * The component inverse schedule is specified as the "map" fields
3888 * of the elements of "domain" indexed by the first "n" elements of "order".
3890 * The schedule domain being "shifted strided" means that the differences
3891 * between the values of the current dimension of domain "i"
3892 * and the values of the current dimension for some reference domain are
3893 * equal to
3895 * stride * integer + offset[i]
3897 * We first look for the domain with the "smallest" value for the current
3898 * dimension and adjust the offsets such that the offset of the "smallest"
3899 * domain is equal to zero. The other offsets are reduced modulo stride.
3901 * Based on this information, we construct a new inverse schedule in
3902 * contruct_shifted_executed that exposes the stride.
3903 * Since this involves the introduction of a new schedule dimension,
3904 * the build needs to be changed accodingly.
3905 * After computing the AST, the newly introduced dimension needs
3906 * to be removed again from the list of grafts. We do this by plugging
3907 * in a mapping that represents the new schedule domain in terms of the
3908 * old schedule domain.
3910 static __isl_give isl_ast_graft_list *generate_shift_component(
3911 struct isl_set_map_pair *domain, int *order, int n,
3912 __isl_keep isl_val *stride, __isl_keep isl_multi_val *offset,
3913 __isl_take isl_ast_build *build)
3915 isl_ast_graft_list *list;
3916 int first;
3917 int depth;
3918 isl_val *val;
3919 isl_multi_val *mv;
3920 isl_space *space;
3921 isl_multi_aff *ma, *zero;
3922 isl_union_map *executed;
3924 depth = isl_ast_build_get_depth(build);
3926 first = first_offset(domain, order, n, build);
3927 if (first < 0)
3928 goto error;
3930 mv = isl_multi_val_copy(offset);
3931 val = isl_multi_val_get_val(offset, first);
3932 val = isl_val_neg(val);
3933 mv = isl_multi_val_add_val(mv, val);
3934 mv = isl_multi_val_mod_val(mv, isl_val_copy(stride));
3936 executed = contruct_shifted_executed(domain, order, n, stride, mv,
3937 build);
3938 space = isl_ast_build_get_space(build, 1);
3939 space = isl_space_map_from_set(space);
3940 ma = isl_multi_aff_identity(isl_space_copy(space));
3941 space = isl_space_from_domain(isl_space_domain(space));
3942 space = isl_space_add_dims(space, isl_dim_out, 1);
3943 zero = isl_multi_aff_zero(space);
3944 ma = isl_multi_aff_range_splice(ma, depth + 1, zero);
3945 build = isl_ast_build_insert_dim(build, depth + 1);
3946 list = generate_shifted_component(executed, build);
3948 list = isl_ast_graft_list_preimage_multi_aff(list, ma);
3950 isl_multi_val_free(mv);
3952 return list;
3953 error:
3954 isl_ast_build_free(build);
3955 return NULL;
3958 /* Does any node in the schedule tree rooted at the current schedule node
3959 * of "build" depend on outer schedule nodes?
3961 static int has_anchored_subtree(__isl_keep isl_ast_build *build)
3963 isl_schedule_node *node;
3964 int dependent = 0;
3966 node = isl_ast_build_get_schedule_node(build);
3967 dependent = isl_schedule_node_is_subtree_anchored(node);
3968 isl_schedule_node_free(node);
3970 return dependent;
3973 /* Generate code for a single component.
3975 * The component inverse schedule is specified as the "map" fields
3976 * of the elements of "domain" indexed by the first "n" elements of "order".
3978 * This function may modify the "set" fields of "domain".
3980 * Before proceeding with the actual code generation for the component,
3981 * we first check if there are any "shifted" strides, meaning that
3982 * the schedule domains of the individual domains are all strided,
3983 * but that they have different offsets, resulting in the union
3984 * of schedule domains not being strided anymore.
3986 * The simplest example is the schedule
3988 * { A[i] -> [2i]: 0 <= i < 10; B[i] -> [2i+1] : 0 <= i < 10 }
3990 * Both schedule domains are strided, but their union is not.
3991 * This function detects such cases and then rewrites the schedule to
3993 * { A[i] -> [2i, 0]: 0 <= i < 10; B[i] -> [2i, 1] : 0 <= i < 10 }
3995 * In the new schedule, the schedule domains have the same offset (modulo
3996 * the stride), ensuring that the union of schedule domains is also strided.
3999 * If there is only a single domain in the component, then there is
4000 * nothing to do. Similarly, if the current schedule dimension has
4001 * a fixed value for almost all domains then there is nothing to be done.
4002 * In particular, we need at least two domains where the current schedule
4003 * dimension does not have a fixed value.
4004 * Finally, in case of a schedule map input,
4005 * if any of the options refer to the current schedule dimension,
4006 * then we bail out as well. It would be possible to reformulate the options
4007 * in terms of the new schedule domain, but that would introduce constraints
4008 * that separate the domains in the options and that is something we would
4009 * like to avoid.
4010 * In the case of a schedule tree input, we bail out if any of
4011 * the descendants of the current schedule node refer to outer
4012 * schedule nodes in any way.
4015 * To see if there is any shifted stride, we look at the differences
4016 * between the values of the current dimension in pairs of domains
4017 * for equal values of outer dimensions. These differences should be
4018 * of the form
4020 * m x + r
4022 * with "m" the stride and "r" a constant. Note that we cannot perform
4023 * this analysis on individual domains as the lower bound in each domain
4024 * may depend on parameters or outer dimensions and so the current dimension
4025 * itself may not have a fixed remainder on division by the stride.
4027 * In particular, we compare the first domain that does not have an
4028 * obviously fixed value for the current dimension to itself and all
4029 * other domains and collect the offsets and the gcd of the strides.
4030 * If the gcd becomes one, then we failed to find shifted strides.
4031 * If the gcd is zero, then the differences were all fixed, meaning
4032 * that some domains had non-obviously fixed values for the current dimension.
4033 * If all the offsets are the same (for those domains that do not have
4034 * an obviously fixed value for the current dimension), then we do not
4035 * apply the transformation.
4036 * If none of the domains were skipped, then there is nothing to do.
4037 * If some of them were skipped, then if we apply separation, the schedule
4038 * domain should get split in pieces with a (non-shifted) stride.
4040 * Otherwise, we apply a shift to expose the stride in
4041 * generate_shift_component.
4043 static __isl_give isl_ast_graft_list *generate_component(
4044 struct isl_set_map_pair *domain, int *order, int n,
4045 __isl_take isl_ast_build *build)
4047 int i, d;
4048 int depth;
4049 isl_ctx *ctx;
4050 isl_map *map;
4051 isl_set *deltas;
4052 isl_val *gcd = NULL;
4053 isl_multi_val *mv;
4054 int fixed, skip;
4055 int base;
4056 isl_ast_graft_list *list;
4057 int res = 0;
4059 depth = isl_ast_build_get_depth(build);
4061 skip = n == 1;
4062 if (skip >= 0 && !skip)
4063 skip = at_most_one_non_fixed(domain, order, n, depth);
4064 if (skip >= 0 && !skip) {
4065 if (isl_ast_build_has_schedule_node(build))
4066 skip = has_anchored_subtree(build);
4067 else
4068 skip = isl_ast_build_options_involve_depth(build);
4070 if (skip < 0)
4071 goto error;
4072 if (skip)
4073 return generate_shifted_component_from_list(domain,
4074 order, n, build);
4076 base = eliminate_non_fixed(domain, order, n, depth, build);
4077 if (base < 0)
4078 goto error;
4080 ctx = isl_ast_build_get_ctx(build);
4082 mv = isl_multi_val_zero(isl_space_set_alloc(ctx, 0, n));
4084 fixed = 1;
4085 for (i = 0; i < n; ++i) {
4086 isl_val *r, *m;
4088 map = isl_map_from_domain_and_range(
4089 isl_set_copy(domain[order[base]].set),
4090 isl_set_copy(domain[order[i]].set));
4091 for (d = 0; d < depth; ++d)
4092 map = isl_map_equate(map, isl_dim_in, d,
4093 isl_dim_out, d);
4094 deltas = isl_map_deltas(map);
4095 res = isl_set_dim_residue_class_val(deltas, depth, &m, &r);
4096 isl_set_free(deltas);
4097 if (res < 0)
4098 break;
4100 if (i == 0)
4101 gcd = m;
4102 else
4103 gcd = isl_val_gcd(gcd, m);
4104 if (isl_val_is_one(gcd)) {
4105 isl_val_free(r);
4106 break;
4108 mv = isl_multi_val_set_val(mv, i, r);
4110 res = dim_is_fixed(domain[order[i]].set, depth);
4111 if (res < 0)
4112 break;
4113 if (res)
4114 continue;
4116 if (fixed && i > base) {
4117 isl_val *a, *b;
4118 a = isl_multi_val_get_val(mv, i);
4119 b = isl_multi_val_get_val(mv, base);
4120 if (isl_val_ne(a, b))
4121 fixed = 0;
4122 isl_val_free(a);
4123 isl_val_free(b);
4127 if (res < 0 || !gcd) {
4128 isl_ast_build_free(build);
4129 list = NULL;
4130 } else if (i < n || fixed || isl_val_is_zero(gcd)) {
4131 list = generate_shifted_component_from_list(domain,
4132 order, n, build);
4133 } else {
4134 list = generate_shift_component(domain, order, n, gcd, mv,
4135 build);
4138 isl_val_free(gcd);
4139 isl_multi_val_free(mv);
4141 return list;
4142 error:
4143 isl_ast_build_free(build);
4144 return NULL;
4147 /* Store both "map" itself and its domain in the
4148 * structure pointed to by *next and advance to the next array element.
4150 static isl_stat extract_domain(__isl_take isl_map *map, void *user)
4152 struct isl_set_map_pair **next = user;
4154 (*next)->map = isl_map_copy(map);
4155 (*next)->set = isl_map_domain(map);
4156 (*next)++;
4158 return isl_stat_ok;
4161 static int after_in_tree(__isl_keep isl_union_map *umap,
4162 __isl_keep isl_schedule_node *node);
4164 /* Is any domain element of "umap" scheduled after any of
4165 * the corresponding image elements by the tree rooted at
4166 * the child of "node"?
4168 static int after_in_child(__isl_keep isl_union_map *umap,
4169 __isl_keep isl_schedule_node *node)
4171 isl_schedule_node *child;
4172 int after;
4174 child = isl_schedule_node_get_child(node, 0);
4175 after = after_in_tree(umap, child);
4176 isl_schedule_node_free(child);
4178 return after;
4181 /* Is any domain element of "umap" scheduled after any of
4182 * the corresponding image elements by the tree rooted at
4183 * the band node "node"?
4185 * We first check if any domain element is scheduled after any
4186 * of the corresponding image elements by the band node itself.
4187 * If not, we restrict "map" to those pairs of element that
4188 * are scheduled together by the band node and continue with
4189 * the child of the band node.
4190 * If there are no such pairs then the map passed to after_in_child
4191 * will be empty causing it to return 0.
4193 static int after_in_band(__isl_keep isl_union_map *umap,
4194 __isl_keep isl_schedule_node *node)
4196 isl_multi_union_pw_aff *mupa;
4197 isl_union_map *partial, *test, *gt, *universe, *umap1, *umap2;
4198 isl_union_set *domain, *range;
4199 isl_space *space;
4200 int empty;
4201 int after;
4203 if (isl_schedule_node_band_n_member(node) == 0)
4204 return after_in_child(umap, node);
4206 mupa = isl_schedule_node_band_get_partial_schedule(node);
4207 space = isl_multi_union_pw_aff_get_space(mupa);
4208 partial = isl_union_map_from_multi_union_pw_aff(mupa);
4209 test = isl_union_map_copy(umap);
4210 test = isl_union_map_apply_domain(test, isl_union_map_copy(partial));
4211 test = isl_union_map_apply_range(test, isl_union_map_copy(partial));
4212 gt = isl_union_map_from_map(isl_map_lex_gt(space));
4213 test = isl_union_map_intersect(test, gt);
4214 empty = isl_union_map_is_empty(test);
4215 isl_union_map_free(test);
4217 if (empty < 0 || !empty) {
4218 isl_union_map_free(partial);
4219 return empty < 0 ? -1 : 1;
4222 universe = isl_union_map_universe(isl_union_map_copy(umap));
4223 domain = isl_union_map_domain(isl_union_map_copy(universe));
4224 range = isl_union_map_range(universe);
4225 umap1 = isl_union_map_copy(partial);
4226 umap1 = isl_union_map_intersect_domain(umap1, domain);
4227 umap2 = isl_union_map_intersect_domain(partial, range);
4228 test = isl_union_map_apply_range(umap1, isl_union_map_reverse(umap2));
4229 test = isl_union_map_intersect(test, isl_union_map_copy(umap));
4230 after = after_in_child(test, node);
4231 isl_union_map_free(test);
4232 return after;
4235 /* Is any domain element of "umap" scheduled after any of
4236 * the corresponding image elements by the tree rooted at
4237 * the context node "node"?
4239 * The context constraints apply to the schedule domain,
4240 * so we cannot apply them directly to "umap", which contains
4241 * pairs of statement instances. Instead, we add them
4242 * to the range of the prefix schedule for both domain and
4243 * range of "umap".
4245 static int after_in_context(__isl_keep isl_union_map *umap,
4246 __isl_keep isl_schedule_node *node)
4248 isl_union_map *prefix, *universe, *umap1, *umap2;
4249 isl_union_set *domain, *range;
4250 isl_set *context;
4251 int after;
4253 umap = isl_union_map_copy(umap);
4254 context = isl_schedule_node_context_get_context(node);
4255 prefix = isl_schedule_node_get_prefix_schedule_union_map(node);
4256 universe = isl_union_map_universe(isl_union_map_copy(umap));
4257 domain = isl_union_map_domain(isl_union_map_copy(universe));
4258 range = isl_union_map_range(universe);
4259 umap1 = isl_union_map_copy(prefix);
4260 umap1 = isl_union_map_intersect_domain(umap1, domain);
4261 umap2 = isl_union_map_intersect_domain(prefix, range);
4262 umap1 = isl_union_map_intersect_range(umap1,
4263 isl_union_set_from_set(context));
4264 umap1 = isl_union_map_apply_range(umap1, isl_union_map_reverse(umap2));
4265 umap = isl_union_map_intersect(umap, umap1);
4267 after = after_in_child(umap, node);
4269 isl_union_map_free(umap);
4271 return after;
4274 /* Is any domain element of "umap" scheduled after any of
4275 * the corresponding image elements by the tree rooted at
4276 * the expansion node "node"?
4278 * We apply the expansion to domain and range of "umap" and
4279 * continue with its child.
4281 static int after_in_expansion(__isl_keep isl_union_map *umap,
4282 __isl_keep isl_schedule_node *node)
4284 isl_union_map *expansion;
4285 int after;
4287 expansion = isl_schedule_node_expansion_get_expansion(node);
4288 umap = isl_union_map_copy(umap);
4289 umap = isl_union_map_apply_domain(umap, isl_union_map_copy(expansion));
4290 umap = isl_union_map_apply_range(umap, expansion);
4292 after = after_in_child(umap, node);
4294 isl_union_map_free(umap);
4296 return after;
4299 /* Is any domain element of "umap" scheduled after any of
4300 * the corresponding image elements by the tree rooted at
4301 * the extension node "node"?
4303 * Since the extension node may add statement instances before or
4304 * after the pairs of statement instances in "umap", we return 1
4305 * to ensure that these pairs are not broken up.
4307 static int after_in_extension(__isl_keep isl_union_map *umap,
4308 __isl_keep isl_schedule_node *node)
4310 return 1;
4313 /* Is any domain element of "umap" scheduled after any of
4314 * the corresponding image elements by the tree rooted at
4315 * the filter node "node"?
4317 * We intersect domain and range of "umap" with the filter and
4318 * continue with its child.
4320 static int after_in_filter(__isl_keep isl_union_map *umap,
4321 __isl_keep isl_schedule_node *node)
4323 isl_union_set *filter;
4324 int after;
4326 umap = isl_union_map_copy(umap);
4327 filter = isl_schedule_node_filter_get_filter(node);
4328 umap = isl_union_map_intersect_domain(umap, isl_union_set_copy(filter));
4329 umap = isl_union_map_intersect_range(umap, filter);
4331 after = after_in_child(umap, node);
4333 isl_union_map_free(umap);
4335 return after;
4338 /* Is any domain element of "umap" scheduled after any of
4339 * the corresponding image elements by the tree rooted at
4340 * the set node "node"?
4342 * This is only the case if this condition holds in any
4343 * of the (filter) children of the set node.
4344 * In particular, if the domain and the range of "umap"
4345 * are contained in different children, then the condition
4346 * does not hold.
4348 static int after_in_set(__isl_keep isl_union_map *umap,
4349 __isl_keep isl_schedule_node *node)
4351 int i, n;
4353 n = isl_schedule_node_n_children(node);
4354 for (i = 0; i < n; ++i) {
4355 isl_schedule_node *child;
4356 int after;
4358 child = isl_schedule_node_get_child(node, i);
4359 after = after_in_tree(umap, child);
4360 isl_schedule_node_free(child);
4362 if (after < 0 || after)
4363 return after;
4366 return 0;
4369 /* Return the filter of child "i" of "node".
4371 static __isl_give isl_union_set *child_filter(
4372 __isl_keep isl_schedule_node *node, int i)
4374 isl_schedule_node *child;
4375 isl_union_set *filter;
4377 child = isl_schedule_node_get_child(node, i);
4378 filter = isl_schedule_node_filter_get_filter(child);
4379 isl_schedule_node_free(child);
4381 return filter;
4384 /* Is any domain element of "umap" scheduled after any of
4385 * the corresponding image elements by the tree rooted at
4386 * the sequence node "node"?
4388 * This happens in particular if any domain element is
4389 * contained in a later child than one containing a range element or
4390 * if the condition holds within a given child in the sequence.
4391 * The later part of the condition is checked by after_in_set.
4393 static int after_in_sequence(__isl_keep isl_union_map *umap,
4394 __isl_keep isl_schedule_node *node)
4396 int i, j, n;
4397 isl_union_map *umap_i;
4398 int empty, after = 0;
4400 n = isl_schedule_node_n_children(node);
4401 for (i = 1; i < n; ++i) {
4402 isl_union_set *filter_i;
4404 umap_i = isl_union_map_copy(umap);
4405 filter_i = child_filter(node, i);
4406 umap_i = isl_union_map_intersect_domain(umap_i, filter_i);
4407 empty = isl_union_map_is_empty(umap_i);
4408 if (empty < 0)
4409 goto error;
4410 if (empty) {
4411 isl_union_map_free(umap_i);
4412 continue;
4415 for (j = 0; j < i; ++j) {
4416 isl_union_set *filter_j;
4417 isl_union_map *umap_ij;
4419 umap_ij = isl_union_map_copy(umap_i);
4420 filter_j = child_filter(node, j);
4421 umap_ij = isl_union_map_intersect_range(umap_ij,
4422 filter_j);
4423 empty = isl_union_map_is_empty(umap_ij);
4424 isl_union_map_free(umap_ij);
4426 if (empty < 0)
4427 goto error;
4428 if (!empty)
4429 after = 1;
4430 if (after)
4431 break;
4434 isl_union_map_free(umap_i);
4435 if (after)
4436 break;
4439 if (after < 0 || after)
4440 return after;
4442 return after_in_set(umap, node);
4443 error:
4444 isl_union_map_free(umap_i);
4445 return -1;
4448 /* Is any domain element of "umap" scheduled after any of
4449 * the corresponding image elements by the tree rooted at "node"?
4451 * If "umap" is empty, then clearly there is no such element.
4452 * Otherwise, consider the different types of nodes separately.
4454 static int after_in_tree(__isl_keep isl_union_map *umap,
4455 __isl_keep isl_schedule_node *node)
4457 int empty;
4458 enum isl_schedule_node_type type;
4460 empty = isl_union_map_is_empty(umap);
4461 if (empty < 0)
4462 return -1;
4463 if (empty)
4464 return 0;
4465 if (!node)
4466 return -1;
4468 type = isl_schedule_node_get_type(node);
4469 switch (type) {
4470 case isl_schedule_node_error:
4471 return -1;
4472 case isl_schedule_node_leaf:
4473 return 0;
4474 case isl_schedule_node_band:
4475 return after_in_band(umap, node);
4476 case isl_schedule_node_domain:
4477 isl_die(isl_schedule_node_get_ctx(node), isl_error_internal,
4478 "unexpected internal domain node", return -1);
4479 case isl_schedule_node_context:
4480 return after_in_context(umap, node);
4481 case isl_schedule_node_expansion:
4482 return after_in_expansion(umap, node);
4483 case isl_schedule_node_extension:
4484 return after_in_extension(umap, node);
4485 case isl_schedule_node_filter:
4486 return after_in_filter(umap, node);
4487 case isl_schedule_node_guard:
4488 case isl_schedule_node_mark:
4489 return after_in_child(umap, node);
4490 case isl_schedule_node_set:
4491 return after_in_set(umap, node);
4492 case isl_schedule_node_sequence:
4493 return after_in_sequence(umap, node);
4496 return 1;
4499 /* Is any domain element of "map1" scheduled after any domain
4500 * element of "map2" by the subtree underneath the current band node,
4501 * while at the same time being scheduled together by the current
4502 * band node, i.e., by "map1" and "map2?
4504 * If the child of the current band node is a leaf, then
4505 * no element can be scheduled after any other element.
4507 * Otherwise, we construct a relation between domain elements
4508 * of "map1" and domain elements of "map2" that are scheduled
4509 * together and then check if the subtree underneath the current
4510 * band node determines their relative order.
4512 static int after_in_subtree(__isl_keep isl_ast_build *build,
4513 __isl_keep isl_map *map1, __isl_keep isl_map *map2)
4515 isl_schedule_node *node;
4516 isl_map *map;
4517 isl_union_map *umap;
4518 int after;
4520 node = isl_ast_build_get_schedule_node(build);
4521 if (!node)
4522 return -1;
4523 node = isl_schedule_node_child(node, 0);
4524 if (isl_schedule_node_get_type(node) == isl_schedule_node_leaf) {
4525 isl_schedule_node_free(node);
4526 return 0;
4528 map = isl_map_copy(map2);
4529 map = isl_map_apply_domain(map, isl_map_copy(map1));
4530 umap = isl_union_map_from_map(map);
4531 after = after_in_tree(umap, node);
4532 isl_union_map_free(umap);
4533 isl_schedule_node_free(node);
4534 return after;
4537 /* Internal data for any_scheduled_after.
4539 * "build" is the build in which the AST is constructed.
4540 * "depth" is the number of loops that have already been generated
4541 * "group_coscheduled" is a local copy of options->ast_build_group_coscheduled
4542 * "domain" is an array of set-map pairs corresponding to the different
4543 * iteration domains. The set is the schedule domain, i.e., the domain
4544 * of the inverse schedule, while the map is the inverse schedule itself.
4546 struct isl_any_scheduled_after_data {
4547 isl_ast_build *build;
4548 int depth;
4549 int group_coscheduled;
4550 struct isl_set_map_pair *domain;
4553 /* Is any element of domain "i" scheduled after any element of domain "j"
4554 * (for a common iteration of the first data->depth loops)?
4556 * data->domain[i].set contains the domain of the inverse schedule
4557 * for domain "i", i.e., elements in the schedule domain.
4559 * If we are inside a band of a schedule tree and there is a pair
4560 * of elements in the two domains that is schedule together by
4561 * the current band, then we check if any element of "i" may be schedule
4562 * after element of "j" by the descendants of the band node.
4564 * If data->group_coscheduled is set, then we also return 1 if there
4565 * is any pair of elements in the two domains that are scheduled together.
4567 static isl_bool any_scheduled_after(int i, int j, void *user)
4569 struct isl_any_scheduled_after_data *data = user;
4570 int dim = isl_set_dim(data->domain[i].set, isl_dim_set);
4571 int pos;
4573 for (pos = data->depth; pos < dim; ++pos) {
4574 int follows;
4576 follows = isl_set_follows_at(data->domain[i].set,
4577 data->domain[j].set, pos);
4579 if (follows < -1)
4580 return isl_bool_error;
4581 if (follows > 0)
4582 return isl_bool_true;
4583 if (follows < 0)
4584 return isl_bool_false;
4587 if (isl_ast_build_has_schedule_node(data->build)) {
4588 int after;
4590 after = after_in_subtree(data->build, data->domain[i].map,
4591 data->domain[j].map);
4592 if (after < 0 || after)
4593 return after;
4596 return data->group_coscheduled;
4599 /* Look for independent components at the current depth and generate code
4600 * for each component separately. The resulting lists of grafts are
4601 * merged in an attempt to combine grafts with identical guards.
4603 * Code for two domains can be generated separately if all the elements
4604 * of one domain are scheduled before (or together with) all the elements
4605 * of the other domain. We therefore consider the graph with as nodes
4606 * the domains and an edge between two nodes if any element of the first
4607 * node is scheduled after any element of the second node.
4608 * If the ast_build_group_coscheduled is set, then we also add an edge if
4609 * there is any pair of elements in the two domains that are scheduled
4610 * together.
4611 * Code is then generated (by generate_component)
4612 * for each of the strongly connected components in this graph
4613 * in their topological order.
4615 * Since the test is performed on the domain of the inverse schedules of
4616 * the different domains, we precompute these domains and store
4617 * them in data.domain.
4619 static __isl_give isl_ast_graft_list *generate_components(
4620 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build)
4622 int i;
4623 isl_ctx *ctx = isl_ast_build_get_ctx(build);
4624 int n = isl_union_map_n_map(executed);
4625 struct isl_any_scheduled_after_data data;
4626 struct isl_set_map_pair *next;
4627 struct isl_tarjan_graph *g = NULL;
4628 isl_ast_graft_list *list = NULL;
4629 int n_domain = 0;
4631 data.domain = isl_calloc_array(ctx, struct isl_set_map_pair, n);
4632 if (!data.domain)
4633 goto error;
4634 n_domain = n;
4636 next = data.domain;
4637 if (isl_union_map_foreach_map(executed, &extract_domain, &next) < 0)
4638 goto error;
4640 if (!build)
4641 goto error;
4642 data.build = build;
4643 data.depth = isl_ast_build_get_depth(build);
4644 data.group_coscheduled = isl_options_get_ast_build_group_coscheduled(ctx);
4645 g = isl_tarjan_graph_init(ctx, n, &any_scheduled_after, &data);
4646 if (!g)
4647 goto error;
4649 list = isl_ast_graft_list_alloc(ctx, 0);
4651 i = 0;
4652 while (list && n) {
4653 isl_ast_graft_list *list_c;
4654 int first = i;
4656 if (g->order[i] == -1)
4657 isl_die(ctx, isl_error_internal, "cannot happen",
4658 goto error);
4659 ++i; --n;
4660 while (g->order[i] != -1) {
4661 ++i; --n;
4664 list_c = generate_component(data.domain,
4665 g->order + first, i - first,
4666 isl_ast_build_copy(build));
4667 list = isl_ast_graft_list_merge(list, list_c, build);
4669 ++i;
4672 if (0)
4673 error: list = isl_ast_graft_list_free(list);
4674 isl_tarjan_graph_free(g);
4675 for (i = 0; i < n_domain; ++i) {
4676 isl_map_free(data.domain[i].map);
4677 isl_set_free(data.domain[i].set);
4679 free(data.domain);
4680 isl_union_map_free(executed);
4681 isl_ast_build_free(build);
4683 return list;
4686 /* Generate code for the next level (and all inner levels).
4688 * If "executed" is empty, i.e., no code needs to be generated,
4689 * then we return an empty list.
4691 * If we have already generated code for all loop levels, then we pass
4692 * control to generate_inner_level.
4694 * If "executed" lives in a single space, i.e., if code needs to be
4695 * generated for a single domain, then there can only be a single
4696 * component and we go directly to generate_shifted_component.
4697 * Otherwise, we call generate_components to detect the components
4698 * and to call generate_component on each of them separately.
4700 static __isl_give isl_ast_graft_list *generate_next_level(
4701 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build)
4703 int depth;
4705 if (!build || !executed)
4706 goto error;
4708 if (isl_union_map_is_empty(executed)) {
4709 isl_ctx *ctx = isl_ast_build_get_ctx(build);
4710 isl_union_map_free(executed);
4711 isl_ast_build_free(build);
4712 return isl_ast_graft_list_alloc(ctx, 0);
4715 depth = isl_ast_build_get_depth(build);
4716 if (depth >= isl_ast_build_dim(build, isl_dim_set))
4717 return generate_inner_level(executed, build);
4719 if (isl_union_map_n_map(executed) == 1)
4720 return generate_shifted_component(executed, build);
4722 return generate_components(executed, build);
4723 error:
4724 isl_union_map_free(executed);
4725 isl_ast_build_free(build);
4726 return NULL;
4729 /* Internal data structure used by isl_ast_build_node_from_schedule_map.
4730 * internal, executed and build are the inputs to generate_code.
4731 * list collects the output.
4733 struct isl_generate_code_data {
4734 int internal;
4735 isl_union_map *executed;
4736 isl_ast_build *build;
4738 isl_ast_graft_list *list;
4741 /* Given an inverse schedule in terms of the external build schedule, i.e.,
4743 * [E -> S] -> D
4745 * with E the external build schedule and S the additional schedule "space",
4746 * reformulate the inverse schedule in terms of the internal schedule domain,
4747 * i.e., return
4749 * [I -> S] -> D
4751 * We first obtain a mapping
4753 * I -> E
4755 * take the inverse and the product with S -> S, resulting in
4757 * [I -> S] -> [E -> S]
4759 * Applying the map to the input produces the desired result.
4761 static __isl_give isl_union_map *internal_executed(
4762 __isl_take isl_union_map *executed, __isl_keep isl_space *space,
4763 __isl_keep isl_ast_build *build)
4765 isl_map *id, *proj;
4767 proj = isl_ast_build_get_schedule_map(build);
4768 proj = isl_map_reverse(proj);
4769 space = isl_space_map_from_set(isl_space_copy(space));
4770 id = isl_map_identity(space);
4771 proj = isl_map_product(proj, id);
4772 executed = isl_union_map_apply_domain(executed,
4773 isl_union_map_from_map(proj));
4774 return executed;
4777 /* Generate an AST that visits the elements in the range of data->executed
4778 * in the relative order specified by the corresponding domain element(s)
4779 * for those domain elements that belong to "set".
4780 * Add the result to data->list.
4782 * The caller ensures that "set" is a universe domain.
4783 * "space" is the space of the additional part of the schedule.
4784 * It is equal to the space of "set" if build->domain is parametric.
4785 * Otherwise, it is equal to the range of the wrapped space of "set".
4787 * If the build space is not parametric and
4788 * if isl_ast_build_node_from_schedule_map
4789 * was called from an outside user (data->internal not set), then
4790 * the (inverse) schedule refers to the external build domain and needs to
4791 * be transformed to refer to the internal build domain.
4793 * If the build space is parametric, then we add some of the parameter
4794 * constraints to the executed relation. Adding these constraints
4795 * allows for an earlier detection of conflicts in some cases.
4796 * However, we do not want to divide the executed relation into
4797 * more disjuncts than necessary. We therefore approximate
4798 * the constraints on the parameters by a single disjunct set.
4800 * The build is extended to include the additional part of the schedule.
4801 * If the original build space was not parametric, then the options
4802 * in data->build refer only to the additional part of the schedule
4803 * and they need to be adjusted to refer to the complete AST build
4804 * domain.
4806 * After having adjusted inverse schedule and build, we start generating
4807 * code with the outer loop of the current code generation
4808 * in generate_next_level.
4810 * If the original build space was not parametric, we undo the embedding
4811 * on the resulting isl_ast_node_list so that it can be used within
4812 * the outer AST build.
4814 static isl_stat generate_code_in_space(struct isl_generate_code_data *data,
4815 __isl_take isl_set *set, __isl_take isl_space *space)
4817 isl_union_map *executed;
4818 isl_ast_build *build;
4819 isl_ast_graft_list *list;
4820 int embed;
4822 executed = isl_union_map_copy(data->executed);
4823 executed = isl_union_map_intersect_domain(executed,
4824 isl_union_set_from_set(set));
4826 embed = !isl_set_is_params(data->build->domain);
4827 if (embed && !data->internal)
4828 executed = internal_executed(executed, space, data->build);
4829 if (!embed) {
4830 isl_set *domain;
4831 domain = isl_ast_build_get_domain(data->build);
4832 domain = isl_set_from_basic_set(isl_set_simple_hull(domain));
4833 executed = isl_union_map_intersect_params(executed, domain);
4836 build = isl_ast_build_copy(data->build);
4837 build = isl_ast_build_product(build, space);
4839 list = generate_next_level(executed, build);
4841 list = isl_ast_graft_list_unembed(list, embed);
4843 data->list = isl_ast_graft_list_concat(data->list, list);
4845 return isl_stat_ok;
4848 /* Generate an AST that visits the elements in the range of data->executed
4849 * in the relative order specified by the corresponding domain element(s)
4850 * for those domain elements that belong to "set".
4851 * Add the result to data->list.
4853 * The caller ensures that "set" is a universe domain.
4855 * If the build space S is not parametric, then the space of "set"
4856 * need to be a wrapped relation with S as domain. That is, it needs
4857 * to be of the form
4859 * [S -> T]
4861 * Check this property and pass control to generate_code_in_space
4862 * passing along T.
4863 * If the build space is not parametric, then T is the space of "set".
4865 static isl_stat generate_code_set(__isl_take isl_set *set, void *user)
4867 struct isl_generate_code_data *data = user;
4868 isl_space *space, *build_space;
4869 int is_domain;
4871 space = isl_set_get_space(set);
4873 if (isl_set_is_params(data->build->domain))
4874 return generate_code_in_space(data, set, space);
4876 build_space = isl_ast_build_get_space(data->build, data->internal);
4877 space = isl_space_unwrap(space);
4878 is_domain = isl_space_is_domain(build_space, space);
4879 isl_space_free(build_space);
4880 space = isl_space_range(space);
4882 if (is_domain < 0)
4883 goto error;
4884 if (!is_domain)
4885 isl_die(isl_set_get_ctx(set), isl_error_invalid,
4886 "invalid nested schedule space", goto error);
4888 return generate_code_in_space(data, set, space);
4889 error:
4890 isl_set_free(set);
4891 isl_space_free(space);
4892 return isl_stat_error;
4895 /* Generate an AST that visits the elements in the range of "executed"
4896 * in the relative order specified by the corresponding domain element(s).
4898 * "build" is an isl_ast_build that has either been constructed by
4899 * isl_ast_build_from_context or passed to a callback set by
4900 * isl_ast_build_set_create_leaf.
4901 * In the first case, the space of the isl_ast_build is typically
4902 * a parametric space, although this is currently not enforced.
4903 * In the second case, the space is never a parametric space.
4904 * If the space S is not parametric, then the domain space(s) of "executed"
4905 * need to be wrapped relations with S as domain.
4907 * If the domain of "executed" consists of several spaces, then an AST
4908 * is generated for each of them (in arbitrary order) and the results
4909 * are concatenated.
4911 * If "internal" is set, then the domain "S" above refers to the internal
4912 * schedule domain representation. Otherwise, it refers to the external
4913 * representation, as returned by isl_ast_build_get_schedule_space.
4915 * We essentially run over all the spaces in the domain of "executed"
4916 * and call generate_code_set on each of them.
4918 static __isl_give isl_ast_graft_list *generate_code(
4919 __isl_take isl_union_map *executed, __isl_take isl_ast_build *build,
4920 int internal)
4922 isl_ctx *ctx;
4923 struct isl_generate_code_data data = { 0 };
4924 isl_space *space;
4925 isl_union_set *schedule_domain;
4926 isl_union_map *universe;
4928 if (!build)
4929 goto error;
4930 space = isl_ast_build_get_space(build, 1);
4931 space = isl_space_align_params(space,
4932 isl_union_map_get_space(executed));
4933 space = isl_space_align_params(space,
4934 isl_union_map_get_space(build->options));
4935 build = isl_ast_build_align_params(build, isl_space_copy(space));
4936 executed = isl_union_map_align_params(executed, space);
4937 if (!executed || !build)
4938 goto error;
4940 ctx = isl_ast_build_get_ctx(build);
4942 data.internal = internal;
4943 data.executed = executed;
4944 data.build = build;
4945 data.list = isl_ast_graft_list_alloc(ctx, 0);
4947 universe = isl_union_map_universe(isl_union_map_copy(executed));
4948 schedule_domain = isl_union_map_domain(universe);
4949 if (isl_union_set_foreach_set(schedule_domain, &generate_code_set,
4950 &data) < 0)
4951 data.list = isl_ast_graft_list_free(data.list);
4953 isl_union_set_free(schedule_domain);
4954 isl_union_map_free(executed);
4956 isl_ast_build_free(build);
4957 return data.list;
4958 error:
4959 isl_union_map_free(executed);
4960 isl_ast_build_free(build);
4961 return NULL;
4964 /* Generate an AST that visits the elements in the domain of "schedule"
4965 * in the relative order specified by the corresponding image element(s).
4967 * "build" is an isl_ast_build that has either been constructed by
4968 * isl_ast_build_from_context or passed to a callback set by
4969 * isl_ast_build_set_create_leaf.
4970 * In the first case, the space of the isl_ast_build is typically
4971 * a parametric space, although this is currently not enforced.
4972 * In the second case, the space is never a parametric space.
4973 * If the space S is not parametric, then the range space(s) of "schedule"
4974 * need to be wrapped relations with S as domain.
4976 * If the range of "schedule" consists of several spaces, then an AST
4977 * is generated for each of them (in arbitrary order) and the results
4978 * are concatenated.
4980 * We first initialize the local copies of the relevant options.
4981 * We do this here rather than when the isl_ast_build is created
4982 * because the options may have changed between the construction
4983 * of the isl_ast_build and the call to isl_generate_code.
4985 * The main computation is performed on an inverse schedule (with
4986 * the schedule domain in the domain and the elements to be executed
4987 * in the range) called "executed".
4989 __isl_give isl_ast_node *isl_ast_build_node_from_schedule_map(
4990 __isl_keep isl_ast_build *build, __isl_take isl_union_map *schedule)
4992 isl_ast_graft_list *list;
4993 isl_ast_node *node;
4994 isl_union_map *executed;
4996 build = isl_ast_build_copy(build);
4997 build = isl_ast_build_set_single_valued(build, 0);
4998 schedule = isl_union_map_coalesce(schedule);
4999 schedule = isl_union_map_remove_redundancies(schedule);
5000 executed = isl_union_map_reverse(schedule);
5001 list = generate_code(executed, isl_ast_build_copy(build), 0);
5002 node = isl_ast_node_from_graft_list(list, build);
5003 isl_ast_build_free(build);
5005 return node;
5008 /* The old name for isl_ast_build_node_from_schedule_map.
5009 * It is being kept for backward compatibility, but
5010 * it will be removed in the future.
5012 __isl_give isl_ast_node *isl_ast_build_ast_from_schedule(
5013 __isl_keep isl_ast_build *build, __isl_take isl_union_map *schedule)
5015 return isl_ast_build_node_from_schedule_map(build, schedule);
5018 /* Generate an AST that visits the elements in the domain of "executed"
5019 * in the relative order specified by the band node "node" and its descendants.
5021 * The relation "executed" maps the outer generated loop iterators
5022 * to the domain elements executed by those iterations.
5024 * If the band is empty, we continue with its descendants.
5025 * Otherwise, we extend the build and the inverse schedule with
5026 * the additional space/partial schedule and continue generating
5027 * an AST in generate_next_level.
5028 * As soon as we have extended the inverse schedule with the additional
5029 * partial schedule, we look for equalities that may exists between
5030 * the old and the new part.
5032 static __isl_give isl_ast_graft_list *build_ast_from_band(
5033 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5034 __isl_take isl_union_map *executed)
5036 isl_space *space;
5037 isl_multi_union_pw_aff *extra;
5038 isl_union_map *extra_umap;
5039 isl_ast_graft_list *list;
5040 unsigned n1, n2;
5042 if (!build || !node || !executed)
5043 goto error;
5045 if (isl_schedule_node_band_n_member(node) == 0)
5046 return build_ast_from_child(build, node, executed);
5048 extra = isl_schedule_node_band_get_partial_schedule(node);
5049 extra = isl_multi_union_pw_aff_align_params(extra,
5050 isl_ast_build_get_space(build, 1));
5051 space = isl_multi_union_pw_aff_get_space(extra);
5053 extra_umap = isl_union_map_from_multi_union_pw_aff(extra);
5054 extra_umap = isl_union_map_reverse(extra_umap);
5056 executed = isl_union_map_domain_product(executed, extra_umap);
5057 executed = isl_union_map_detect_equalities(executed);
5059 n1 = isl_ast_build_dim(build, isl_dim_param);
5060 build = isl_ast_build_product(build, space);
5061 n2 = isl_ast_build_dim(build, isl_dim_param);
5062 if (n2 > n1)
5063 isl_die(isl_ast_build_get_ctx(build), isl_error_invalid,
5064 "band node is not allowed to introduce new parameters",
5065 build = isl_ast_build_free(build));
5066 build = isl_ast_build_set_schedule_node(build, node);
5068 list = generate_next_level(executed, build);
5070 list = isl_ast_graft_list_unembed(list, 1);
5072 return list;
5073 error:
5074 isl_schedule_node_free(node);
5075 isl_union_map_free(executed);
5076 isl_ast_build_free(build);
5077 return NULL;
5080 /* Hoist a list of grafts (in practice containing a single graft)
5081 * from "sub_build" (which includes extra context information)
5082 * to "build".
5084 * In particular, project out all additional parameters introduced
5085 * by the context node from the enforced constraints and the guard
5086 * of the single graft.
5088 static __isl_give isl_ast_graft_list *hoist_out_of_context(
5089 __isl_take isl_ast_graft_list *list, __isl_keep isl_ast_build *build,
5090 __isl_keep isl_ast_build *sub_build)
5092 isl_ast_graft *graft;
5093 isl_basic_set *enforced;
5094 isl_set *guard;
5095 unsigned n_param, extra_param;
5097 if (!build || !sub_build)
5098 return isl_ast_graft_list_free(list);
5100 n_param = isl_ast_build_dim(build, isl_dim_param);
5101 extra_param = isl_ast_build_dim(sub_build, isl_dim_param);
5103 if (extra_param == n_param)
5104 return list;
5106 extra_param -= n_param;
5107 enforced = isl_ast_graft_list_extract_shared_enforced(list, sub_build);
5108 enforced = isl_basic_set_project_out(enforced, isl_dim_param,
5109 n_param, extra_param);
5110 enforced = isl_basic_set_remove_unknown_divs(enforced);
5111 guard = isl_ast_graft_list_extract_hoistable_guard(list, sub_build);
5112 guard = isl_set_remove_divs_involving_dims(guard, isl_dim_param,
5113 n_param, extra_param);
5114 guard = isl_set_project_out(guard, isl_dim_param, n_param, extra_param);
5115 guard = isl_set_compute_divs(guard);
5116 graft = isl_ast_graft_alloc_from_children(list, guard, enforced,
5117 build, sub_build);
5118 list = isl_ast_graft_list_from_ast_graft(graft);
5120 return list;
5123 /* Generate an AST that visits the elements in the domain of "executed"
5124 * in the relative order specified by the context node "node"
5125 * and its descendants.
5127 * The relation "executed" maps the outer generated loop iterators
5128 * to the domain elements executed by those iterations.
5130 * The context node may introduce additional parameters as well as
5131 * constraints on the outer schedule dimenions or original parameters.
5133 * We add the extra parameters to a new build and the context
5134 * constraints to both the build and (as a single disjunct)
5135 * to the domain of "executed". Since the context constraints
5136 * are specified in terms of the input schedule, we first need
5137 * to map them to the internal schedule domain.
5139 * After constructing the AST from the descendants of "node",
5140 * we combine the list of grafts into a single graft within
5141 * the new build, in order to be able to exploit the additional
5142 * context constraints during this combination.
5144 * Additionally, if the current node is the outermost node in
5145 * the schedule tree (apart from the root domain node), we generate
5146 * all pending guards, again to be able to exploit the additional
5147 * context constraints. We currently do not do this for internal
5148 * context nodes since we may still want to hoist conditions
5149 * to outer AST nodes.
5151 * If the context node introduced any new parameters, then they
5152 * are removed from the set of enforced constraints and guard
5153 * in hoist_out_of_context.
5155 static __isl_give isl_ast_graft_list *build_ast_from_context(
5156 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5157 __isl_take isl_union_map *executed)
5159 isl_set *context;
5160 isl_space *space;
5161 isl_multi_aff *internal2input;
5162 isl_ast_build *sub_build;
5163 isl_ast_graft_list *list;
5164 int n, depth;
5166 depth = isl_schedule_node_get_tree_depth(node);
5167 space = isl_ast_build_get_space(build, 1);
5168 context = isl_schedule_node_context_get_context(node);
5169 context = isl_set_align_params(context, space);
5170 sub_build = isl_ast_build_copy(build);
5171 space = isl_set_get_space(context);
5172 sub_build = isl_ast_build_align_params(sub_build, space);
5173 internal2input = isl_ast_build_get_internal2input(sub_build);
5174 context = isl_set_preimage_multi_aff(context, internal2input);
5175 sub_build = isl_ast_build_restrict_generated(sub_build,
5176 isl_set_copy(context));
5177 context = isl_set_from_basic_set(isl_set_simple_hull(context));
5178 executed = isl_union_map_intersect_domain(executed,
5179 isl_union_set_from_set(context));
5181 list = build_ast_from_child(isl_ast_build_copy(sub_build),
5182 node, executed);
5183 n = isl_ast_graft_list_n_ast_graft(list);
5184 if (n < 0)
5185 list = isl_ast_graft_list_free(list);
5187 list = isl_ast_graft_list_fuse(list, sub_build);
5188 if (depth == 1)
5189 list = isl_ast_graft_list_insert_pending_guard_nodes(list,
5190 sub_build);
5191 if (n >= 1)
5192 list = hoist_out_of_context(list, build, sub_build);
5194 isl_ast_build_free(build);
5195 isl_ast_build_free(sub_build);
5197 return list;
5200 /* Generate an AST that visits the elements in the domain of "executed"
5201 * in the relative order specified by the expansion node "node" and
5202 * its descendants.
5204 * The relation "executed" maps the outer generated loop iterators
5205 * to the domain elements executed by those iterations.
5207 * We expand the domain elements by the expansion and
5208 * continue with the descendants of the node.
5210 static __isl_give isl_ast_graft_list *build_ast_from_expansion(
5211 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5212 __isl_take isl_union_map *executed)
5214 isl_union_map *expansion;
5215 unsigned n1, n2;
5217 expansion = isl_schedule_node_expansion_get_expansion(node);
5218 expansion = isl_union_map_align_params(expansion,
5219 isl_union_map_get_space(executed));
5221 n1 = isl_union_map_dim(executed, isl_dim_param);
5222 executed = isl_union_map_apply_range(executed, expansion);
5223 n2 = isl_union_map_dim(executed, isl_dim_param);
5224 if (n2 > n1)
5225 isl_die(isl_ast_build_get_ctx(build), isl_error_invalid,
5226 "expansion node is not allowed to introduce "
5227 "new parameters", goto error);
5229 return build_ast_from_child(build, node, executed);
5230 error:
5231 isl_ast_build_free(build);
5232 isl_schedule_node_free(node);
5233 isl_union_map_free(executed);
5234 return NULL;
5237 /* Generate an AST that visits the elements in the domain of "executed"
5238 * in the relative order specified by the extension node "node" and
5239 * its descendants.
5241 * The relation "executed" maps the outer generated loop iterators
5242 * to the domain elements executed by those iterations.
5244 * Extend the inverse schedule with the extension applied to current
5245 * set of generated constraints. Since the extension if formulated
5246 * in terms of the input schedule, it first needs to be transformed
5247 * to refer to the internal schedule.
5249 static __isl_give isl_ast_graft_list *build_ast_from_extension(
5250 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5251 __isl_take isl_union_map *executed)
5253 isl_union_set *schedule_domain;
5254 isl_union_map *extension;
5255 isl_set *set;
5257 set = isl_ast_build_get_generated(build);
5258 set = isl_set_from_basic_set(isl_set_simple_hull(set));
5259 schedule_domain = isl_union_set_from_set(set);
5261 extension = isl_schedule_node_extension_get_extension(node);
5263 extension = isl_union_map_preimage_domain_multi_aff(extension,
5264 isl_multi_aff_copy(build->internal2input));
5265 extension = isl_union_map_intersect_domain(extension, schedule_domain);
5266 extension = isl_ast_build_substitute_values_union_map_domain(build,
5267 extension);
5268 executed = isl_union_map_union(executed, extension);
5270 return build_ast_from_child(build, node, executed);
5273 /* Generate an AST that visits the elements in the domain of "executed"
5274 * in the relative order specified by the filter node "node" and
5275 * its descendants.
5277 * The relation "executed" maps the outer generated loop iterators
5278 * to the domain elements executed by those iterations.
5280 * We simply intersect the iteration domain (i.e., the range of "executed")
5281 * with the filter and continue with the descendants of the node,
5282 * unless the resulting inverse schedule is empty, in which
5283 * case we return an empty list.
5285 * If the result of the intersection is equal to the original "executed"
5286 * relation, then keep the original representation since the intersection
5287 * may have unnecessarily broken up the relation into a greater number
5288 * of disjuncts.
5290 static __isl_give isl_ast_graft_list *build_ast_from_filter(
5291 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5292 __isl_take isl_union_map *executed)
5294 isl_ctx *ctx;
5295 isl_union_set *filter;
5296 isl_union_map *orig;
5297 isl_ast_graft_list *list;
5298 int empty;
5299 isl_bool unchanged;
5300 unsigned n1, n2;
5302 orig = isl_union_map_copy(executed);
5303 if (!build || !node || !executed)
5304 goto error;
5306 filter = isl_schedule_node_filter_get_filter(node);
5307 filter = isl_union_set_align_params(filter,
5308 isl_union_map_get_space(executed));
5309 n1 = isl_union_map_dim(executed, isl_dim_param);
5310 executed = isl_union_map_intersect_range(executed, filter);
5311 n2 = isl_union_map_dim(executed, isl_dim_param);
5312 if (n2 > n1)
5313 isl_die(isl_ast_build_get_ctx(build), isl_error_invalid,
5314 "filter node is not allowed to introduce "
5315 "new parameters", goto error);
5317 unchanged = isl_union_map_is_subset(orig, executed);
5318 empty = isl_union_map_is_empty(executed);
5319 if (unchanged < 0 || empty < 0)
5320 goto error;
5321 if (unchanged) {
5322 isl_union_map_free(executed);
5323 return build_ast_from_child(build, node, orig);
5325 isl_union_map_free(orig);
5326 if (!empty)
5327 return build_ast_from_child(build, node, executed);
5329 ctx = isl_ast_build_get_ctx(build);
5330 list = isl_ast_graft_list_alloc(ctx, 0);
5331 isl_ast_build_free(build);
5332 isl_schedule_node_free(node);
5333 isl_union_map_free(executed);
5334 return list;
5335 error:
5336 isl_ast_build_free(build);
5337 isl_schedule_node_free(node);
5338 isl_union_map_free(executed);
5339 isl_union_map_free(orig);
5340 return NULL;
5343 /* Generate an AST that visits the elements in the domain of "executed"
5344 * in the relative order specified by the guard node "node" and
5345 * its descendants.
5347 * The relation "executed" maps the outer generated loop iterators
5348 * to the domain elements executed by those iterations.
5350 * Ensure that the associated guard is enforced by the outer AST
5351 * constructs by adding it to the guard of the graft.
5352 * Since we know that we will enforce the guard, we can also include it
5353 * in the generated constraints used to construct an AST for
5354 * the descendant nodes.
5356 static __isl_give isl_ast_graft_list *build_ast_from_guard(
5357 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5358 __isl_take isl_union_map *executed)
5360 isl_space *space;
5361 isl_set *guard, *hoisted;
5362 isl_basic_set *enforced;
5363 isl_ast_build *sub_build;
5364 isl_ast_graft *graft;
5365 isl_ast_graft_list *list;
5366 unsigned n1, n2;
5368 space = isl_ast_build_get_space(build, 1);
5369 guard = isl_schedule_node_guard_get_guard(node);
5370 n1 = isl_space_dim(space, isl_dim_param);
5371 guard = isl_set_align_params(guard, space);
5372 n2 = isl_set_dim(guard, isl_dim_param);
5373 if (n2 > n1)
5374 isl_die(isl_ast_build_get_ctx(build), isl_error_invalid,
5375 "guard node is not allowed to introduce "
5376 "new parameters", guard = isl_set_free(guard));
5377 guard = isl_set_preimage_multi_aff(guard,
5378 isl_multi_aff_copy(build->internal2input));
5379 guard = isl_ast_build_specialize(build, guard);
5380 guard = isl_set_gist(guard, isl_set_copy(build->generated));
5382 sub_build = isl_ast_build_copy(build);
5383 sub_build = isl_ast_build_restrict_generated(sub_build,
5384 isl_set_copy(guard));
5386 list = build_ast_from_child(isl_ast_build_copy(sub_build),
5387 node, executed);
5389 hoisted = isl_ast_graft_list_extract_hoistable_guard(list, sub_build);
5390 if (isl_set_n_basic_set(hoisted) > 1)
5391 list = isl_ast_graft_list_gist_guards(list,
5392 isl_set_copy(hoisted));
5393 guard = isl_set_intersect(guard, hoisted);
5394 enforced = extract_shared_enforced(list, build);
5395 graft = isl_ast_graft_alloc_from_children(list, guard, enforced,
5396 build, sub_build);
5398 isl_ast_build_free(sub_build);
5399 isl_ast_build_free(build);
5400 return isl_ast_graft_list_from_ast_graft(graft);
5403 /* Call the before_each_mark callback, if requested by the user.
5405 * Return 0 on success and -1 on error.
5407 * The caller is responsible for recording the current inverse schedule
5408 * in "build".
5410 static isl_stat before_each_mark(__isl_keep isl_id *mark,
5411 __isl_keep isl_ast_build *build)
5413 if (!build)
5414 return isl_stat_error;
5415 if (!build->before_each_mark)
5416 return isl_stat_ok;
5417 return build->before_each_mark(mark, build,
5418 build->before_each_mark_user);
5421 /* Call the after_each_mark callback, if requested by the user.
5423 * The caller is responsible for recording the current inverse schedule
5424 * in "build".
5426 static __isl_give isl_ast_graft *after_each_mark(
5427 __isl_take isl_ast_graft *graft, __isl_keep isl_ast_build *build)
5429 if (!graft || !build)
5430 return isl_ast_graft_free(graft);
5431 if (!build->after_each_mark)
5432 return graft;
5433 graft->node = build->after_each_mark(graft->node, build,
5434 build->after_each_mark_user);
5435 if (!graft->node)
5436 return isl_ast_graft_free(graft);
5437 return graft;
5441 /* Generate an AST that visits the elements in the domain of "executed"
5442 * in the relative order specified by the mark node "node" and
5443 * its descendants.
5445 * The relation "executed" maps the outer generated loop iterators
5446 * to the domain elements executed by those iterations.
5448 * Since we may be calling before_each_mark and after_each_mark
5449 * callbacks, we record the current inverse schedule in the build.
5451 * We generate an AST for the child of the mark node, combine
5452 * the graft list into a single graft and then insert the mark
5453 * in the AST of that single graft.
5455 static __isl_give isl_ast_graft_list *build_ast_from_mark(
5456 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5457 __isl_take isl_union_map *executed)
5459 isl_id *mark;
5460 isl_ast_graft *graft;
5461 isl_ast_graft_list *list;
5462 int n;
5464 build = isl_ast_build_set_executed(build, isl_union_map_copy(executed));
5466 mark = isl_schedule_node_mark_get_id(node);
5467 if (before_each_mark(mark, build) < 0)
5468 node = isl_schedule_node_free(node);
5470 list = build_ast_from_child(isl_ast_build_copy(build), node, executed);
5471 list = isl_ast_graft_list_fuse(list, build);
5472 n = isl_ast_graft_list_n_ast_graft(list);
5473 if (n < 0)
5474 list = isl_ast_graft_list_free(list);
5475 if (n == 0) {
5476 isl_id_free(mark);
5477 } else {
5478 graft = isl_ast_graft_list_get_ast_graft(list, 0);
5479 graft = isl_ast_graft_insert_mark(graft, mark);
5480 graft = after_each_mark(graft, build);
5481 list = isl_ast_graft_list_set_ast_graft(list, 0, graft);
5483 isl_ast_build_free(build);
5485 return list;
5488 static __isl_give isl_ast_graft_list *build_ast_from_schedule_node(
5489 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5490 __isl_take isl_union_map *executed);
5492 /* Generate an AST that visits the elements in the domain of "executed"
5493 * in the relative order specified by the sequence (or set) node "node" and
5494 * its descendants.
5496 * The relation "executed" maps the outer generated loop iterators
5497 * to the domain elements executed by those iterations.
5499 * We simply generate an AST for each of the children and concatenate
5500 * the results.
5502 static __isl_give isl_ast_graft_list *build_ast_from_sequence(
5503 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5504 __isl_take isl_union_map *executed)
5506 int i, n;
5507 isl_ctx *ctx;
5508 isl_ast_graft_list *list;
5510 ctx = isl_ast_build_get_ctx(build);
5511 list = isl_ast_graft_list_alloc(ctx, 0);
5513 n = isl_schedule_node_n_children(node);
5514 for (i = 0; i < n; ++i) {
5515 isl_schedule_node *child;
5516 isl_ast_graft_list *list_i;
5518 child = isl_schedule_node_get_child(node, i);
5519 list_i = build_ast_from_schedule_node(isl_ast_build_copy(build),
5520 child, isl_union_map_copy(executed));
5521 list = isl_ast_graft_list_concat(list, list_i);
5523 isl_ast_build_free(build);
5524 isl_schedule_node_free(node);
5525 isl_union_map_free(executed);
5527 return list;
5530 /* Generate an AST that visits the elements in the domain of "executed"
5531 * in the relative order specified by the node "node" and its descendants.
5533 * The relation "executed" maps the outer generated loop iterators
5534 * to the domain elements executed by those iterations.
5536 * If the node is a leaf, then we pass control to generate_inner_level.
5537 * Note that the current build does not refer to any band node, so
5538 * that generate_inner_level will not try to visit the child of
5539 * the leaf node.
5541 * The other node types are handled in separate functions.
5542 * Set nodes are currently treated in the same way as sequence nodes.
5543 * The children of a set node may be executed in any order,
5544 * including the order of the children.
5546 static __isl_give isl_ast_graft_list *build_ast_from_schedule_node(
5547 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5548 __isl_take isl_union_map *executed)
5550 enum isl_schedule_node_type type;
5552 type = isl_schedule_node_get_type(node);
5554 switch (type) {
5555 case isl_schedule_node_error:
5556 goto error;
5557 case isl_schedule_node_leaf:
5558 isl_schedule_node_free(node);
5559 return generate_inner_level(executed, build);
5560 case isl_schedule_node_band:
5561 return build_ast_from_band(build, node, executed);
5562 case isl_schedule_node_context:
5563 return build_ast_from_context(build, node, executed);
5564 case isl_schedule_node_domain:
5565 isl_die(isl_schedule_node_get_ctx(node), isl_error_unsupported,
5566 "unexpected internal domain node", goto error);
5567 case isl_schedule_node_expansion:
5568 return build_ast_from_expansion(build, node, executed);
5569 case isl_schedule_node_extension:
5570 return build_ast_from_extension(build, node, executed);
5571 case isl_schedule_node_filter:
5572 return build_ast_from_filter(build, node, executed);
5573 case isl_schedule_node_guard:
5574 return build_ast_from_guard(build, node, executed);
5575 case isl_schedule_node_mark:
5576 return build_ast_from_mark(build, node, executed);
5577 case isl_schedule_node_sequence:
5578 case isl_schedule_node_set:
5579 return build_ast_from_sequence(build, node, executed);
5582 isl_die(isl_ast_build_get_ctx(build), isl_error_internal,
5583 "unhandled type", goto error);
5584 error:
5585 isl_union_map_free(executed);
5586 isl_schedule_node_free(node);
5587 isl_ast_build_free(build);
5589 return NULL;
5592 /* Generate an AST that visits the elements in the domain of "executed"
5593 * in the relative order specified by the (single) child of "node" and
5594 * its descendants.
5596 * The relation "executed" maps the outer generated loop iterators
5597 * to the domain elements executed by those iterations.
5599 * This function is never called on a leaf, set or sequence node,
5600 * so the node always has exactly one child.
5602 static __isl_give isl_ast_graft_list *build_ast_from_child(
5603 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node,
5604 __isl_take isl_union_map *executed)
5606 node = isl_schedule_node_child(node, 0);
5607 return build_ast_from_schedule_node(build, node, executed);
5610 /* Generate an AST that visits the elements in the domain of the domain
5611 * node "node" in the relative order specified by its descendants.
5613 * An initial inverse schedule is created that maps a zero-dimensional
5614 * schedule space to the node domain.
5615 * The input "build" is assumed to have a parametric domain and
5616 * is replaced by the same zero-dimensional schedule space.
5618 * We also add some of the parameter constraints in the build domain
5619 * to the executed relation. Adding these constraints
5620 * allows for an earlier detection of conflicts in some cases.
5621 * However, we do not want to divide the executed relation into
5622 * more disjuncts than necessary. We therefore approximate
5623 * the constraints on the parameters by a single disjunct set.
5625 static __isl_give isl_ast_node *build_ast_from_domain(
5626 __isl_take isl_ast_build *build, __isl_take isl_schedule_node *node)
5628 isl_ctx *ctx;
5629 isl_union_set *domain, *schedule_domain;
5630 isl_union_map *executed;
5631 isl_space *space;
5632 isl_set *set;
5633 isl_ast_graft_list *list;
5634 isl_ast_node *ast;
5635 int is_params;
5637 if (!build)
5638 goto error;
5640 ctx = isl_ast_build_get_ctx(build);
5641 space = isl_ast_build_get_space(build, 1);
5642 is_params = isl_space_is_params(space);
5643 isl_space_free(space);
5644 if (is_params < 0)
5645 goto error;
5646 if (!is_params)
5647 isl_die(ctx, isl_error_unsupported,
5648 "expecting parametric initial context", goto error);
5650 domain = isl_schedule_node_domain_get_domain(node);
5651 domain = isl_union_set_coalesce(domain);
5653 space = isl_union_set_get_space(domain);
5654 space = isl_space_set_from_params(space);
5655 build = isl_ast_build_product(build, space);
5657 set = isl_ast_build_get_domain(build);
5658 set = isl_set_from_basic_set(isl_set_simple_hull(set));
5659 schedule_domain = isl_union_set_from_set(set);
5661 executed = isl_union_map_from_domain_and_range(schedule_domain, domain);
5662 list = build_ast_from_child(isl_ast_build_copy(build), node, executed);
5663 ast = isl_ast_node_from_graft_list(list, build);
5664 isl_ast_build_free(build);
5666 return ast;
5667 error:
5668 isl_schedule_node_free(node);
5669 isl_ast_build_free(build);
5670 return NULL;
5673 /* Generate an AST that visits the elements in the domain of "schedule"
5674 * in the relative order specified by the schedule tree.
5676 * "build" is an isl_ast_build that has been created using
5677 * isl_ast_build_alloc or isl_ast_build_from_context based
5678 * on a parametric set.
5680 * The construction starts at the root node of the schedule,
5681 * which is assumed to be a domain node.
5683 __isl_give isl_ast_node *isl_ast_build_node_from_schedule(
5684 __isl_keep isl_ast_build *build, __isl_take isl_schedule *schedule)
5686 isl_ctx *ctx;
5687 isl_schedule_node *node;
5689 if (!build || !schedule)
5690 goto error;
5692 ctx = isl_ast_build_get_ctx(build);
5694 node = isl_schedule_get_root(schedule);
5695 isl_schedule_free(schedule);
5697 build = isl_ast_build_copy(build);
5698 build = isl_ast_build_set_single_valued(build, 0);
5699 if (isl_schedule_node_get_type(node) != isl_schedule_node_domain)
5700 isl_die(ctx, isl_error_unsupported,
5701 "expecting root domain node",
5702 build = isl_ast_build_free(build));
5703 return build_ast_from_domain(build, node);
5704 error:
5705 isl_schedule_free(schedule);
5706 return NULL;