PetScan::scan: detect and report unbalanced pairs of scop/endscop pragmas
[pet.git] / tree2scop.c
blob23cdd3c6594b942b6027043db8bb08aceb4f2337
1 /*
2 * Copyright 2011 Leiden University. All rights reserved.
3 * Copyright 2012-2014 Ecole Normale Superieure. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following
14 * disclaimer in the documentation and/or other materials provided
15 * with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY LEIDEN UNIVERSITY ''AS IS'' AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL LEIDEN UNIVERSITY OR
21 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
24 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 * The views and conclusions contained in the software and documentation
30 * are those of the authors and should not be interpreted as
31 * representing official policies, either expressed or implied, of
32 * Leiden University.
35 #include <stdlib.h>
36 #include <string.h>
38 #include <isl/id_to_pw_aff.h>
39 #include <isl/union_set.h>
41 #include "aff.h"
42 #include "expr.h"
43 #include "expr_arg.h"
44 #include "nest.h"
45 #include "scop.h"
46 #include "skip.h"
47 #include "state.h"
48 #include "tree2scop.h"
50 /* Update "pc" by taking into account the writes in "stmt".
51 * That is, clear any previously assigned values to variables
52 * that are written by "stmt".
54 static __isl_give pet_context *handle_writes(struct pet_stmt *stmt,
55 __isl_take pet_context *pc)
57 return pet_context_clear_writes_in_tree(pc, stmt->body);
60 /* Update "pc" based on the write accesses in "scop".
62 static __isl_give pet_context *scop_handle_writes(struct pet_scop *scop,
63 __isl_take pet_context *pc)
65 int i;
67 if (!scop)
68 return pet_context_free(pc);
69 for (i = 0; i < scop->n_stmt; ++i)
70 pc = handle_writes(scop->stmts[i], pc);
72 return pc;
75 /* Wrapper around pet_expr_resolve_assume
76 * for use as a callback to pet_tree_map_expr.
78 static __isl_give pet_expr *resolve_assume(__isl_take pet_expr *expr,
79 void *user)
81 pet_context *pc = user;
83 return pet_expr_resolve_assume(expr, pc);
86 /* Check if any expression inside "tree" is an assume expression and
87 * if its single argument can be converted to an affine expression
88 * in the context of "pc".
89 * If so, replace the argument by the affine expression.
91 __isl_give pet_tree *pet_tree_resolve_assume(__isl_take pet_tree *tree,
92 __isl_keep pet_context *pc)
94 return pet_tree_map_expr(tree, &resolve_assume, pc);
97 /* Convert a pet_tree to a pet_scop with one statement within the context "pc".
98 * "tree" has already been evaluated in the context of "pc".
99 * This mainly involves resolving nested expression parameters
100 * and setting the name of the iteration space.
101 * The name is given by tree->label if it is non-NULL. Otherwise,
102 * it is of the form S_<stmt_nr>.
104 static struct pet_scop *scop_from_evaluated_tree(__isl_take pet_tree *tree,
105 int stmt_nr, __isl_keep pet_context *pc)
107 isl_space *space;
108 isl_set *domain;
109 struct pet_stmt *ps;
111 space = pet_context_get_space(pc);
113 tree = pet_tree_resolve_nested(tree, space);
114 tree = pet_tree_resolve_assume(tree, pc);
116 domain = pet_context_get_domain(pc);
117 ps = pet_stmt_from_pet_tree(domain, stmt_nr, tree);
118 return pet_scop_from_pet_stmt(space, ps);
121 /* Convert a top-level pet_expr to a pet_scop with one statement
122 * within the context "pc".
123 * "expr" has already been evaluated in the context of "pc".
124 * We construct a pet_tree from "expr" and continue with
125 * scop_from_evaluated_tree.
126 * The name is of the form S_<stmt_nr>.
127 * The location of the statement is set to "loc".
129 static struct pet_scop *scop_from_evaluated_expr(__isl_take pet_expr *expr,
130 int stmt_nr, __isl_take pet_loc *loc, __isl_keep pet_context *pc)
132 pet_tree *tree;
134 tree = pet_tree_new_expr(expr);
135 tree = pet_tree_set_loc(tree, loc);
136 return scop_from_evaluated_tree(tree, stmt_nr, pc);
139 /* Convert a pet_tree to a pet_scop with one statement within the context "pc".
140 * "tree" has not yet been evaluated in the context of "pc".
141 * We evaluate "tree" in the context of "pc" and continue with
142 * scop_from_evaluated_tree.
143 * The statement name is given by tree->label if it is non-NULL. Otherwise,
144 * it is of the form S_<stmt_nr>.
146 static struct pet_scop *scop_from_unevaluated_tree(__isl_take pet_tree *tree,
147 int stmt_nr, __isl_keep pet_context *pc)
149 tree = pet_context_evaluate_tree(pc, tree);
150 return scop_from_evaluated_tree(tree, stmt_nr, pc);
153 /* Convert a top-level pet_expr to a pet_scop with one statement
154 * within the context "pc", where "expr" has not yet been evaluated
155 * in the context of "pc".
156 * We construct a pet_tree from "expr" and continue with
157 * scop_from_unevaluated_tree.
158 * The statement name is of the form S_<stmt_nr>.
159 * The location of the statement is set to "loc".
161 static struct pet_scop *scop_from_expr(__isl_take pet_expr *expr,
162 int stmt_nr, __isl_take pet_loc *loc, __isl_keep pet_context *pc)
164 pet_tree *tree;
166 tree = pet_tree_new_expr(expr);
167 tree = pet_tree_set_loc(tree, loc);
168 return scop_from_unevaluated_tree(tree, stmt_nr, pc);
171 /* Construct a pet_scop with a single statement killing the entire
172 * array "array".
173 * The location of the statement is set to "loc".
175 static struct pet_scop *kill(__isl_take pet_loc *loc, struct pet_array *array,
176 __isl_keep pet_context *pc, struct pet_state *state)
178 isl_ctx *ctx;
179 isl_id *id;
180 isl_space *space;
181 isl_multi_pw_aff *index;
182 isl_map *access;
183 pet_expr *expr;
184 struct pet_scop *scop;
186 if (!array)
187 goto error;
188 ctx = isl_set_get_ctx(array->extent);
189 access = isl_map_from_range(isl_set_copy(array->extent));
190 id = isl_set_get_tuple_id(array->extent);
191 space = isl_space_alloc(ctx, 0, 0, 0);
192 space = isl_space_set_tuple_id(space, isl_dim_out, id);
193 index = isl_multi_pw_aff_zero(space);
194 expr = pet_expr_kill_from_access_and_index(access, index);
195 return scop_from_expr(expr, state->n_stmt++, loc, pc);
196 error:
197 pet_loc_free(loc);
198 return NULL;
201 /* Construct and return a pet_array corresponding to the variable
202 * accessed by "access" by calling the extract_array callback.
204 static struct pet_array *extract_array(__isl_keep pet_expr *access,
205 __isl_keep pet_context *pc, struct pet_state *state)
207 return state->extract_array(access, pc, state->user);
210 /* Construct a pet_scop for a (single) variable declaration
211 * within the context "pc".
213 * The scop contains the variable being declared (as an array)
214 * and a statement killing the array.
216 * If the declaration comes with an initialization, then the scop
217 * also contains an assignment to the variable.
219 static struct pet_scop *scop_from_decl(__isl_keep pet_tree *tree,
220 __isl_keep pet_context *pc, struct pet_state *state)
222 int type_size;
223 isl_ctx *ctx;
224 struct pet_array *array;
225 struct pet_scop *scop_decl, *scop;
226 pet_expr *lhs, *rhs, *pe;
228 array = extract_array(tree->u.d.var, pc, state);
229 if (array)
230 array->declared = 1;
231 scop_decl = kill(pet_tree_get_loc(tree), array, pc, state);
232 scop_decl = pet_scop_add_array(scop_decl, array);
234 if (tree->type != pet_tree_decl_init)
235 return scop_decl;
237 lhs = pet_expr_copy(tree->u.d.var);
238 rhs = pet_expr_copy(tree->u.d.init);
239 type_size = pet_expr_get_type_size(lhs);
240 pe = pet_expr_new_binary(type_size, pet_op_assign, lhs, rhs);
241 scop = scop_from_expr(pe, state->n_stmt++, pet_tree_get_loc(tree), pc);
243 ctx = pet_tree_get_ctx(tree);
244 scop = pet_scop_add_seq(ctx, scop_decl, scop);
246 return scop;
249 /* Does "tree" represent a kill statement?
250 * That is, is it an expression statement that "calls" __pencil_kill?
252 static int is_pencil_kill(__isl_keep pet_tree *tree)
254 pet_expr *expr;
255 const char *name;
257 if (!tree)
258 return -1;
259 if (tree->type != pet_tree_expr)
260 return 0;
261 expr = tree->u.e.expr;
262 if (pet_expr_get_type(expr) != pet_expr_call)
263 return 0;
264 name = pet_expr_call_get_name(expr);
265 if (!name)
266 return -1;
267 return !strcmp(name, "__pencil_kill");
270 /* Add a kill to "scop" that kills what is accessed by
271 * the access expression "expr".
273 * Mark the access as a write prior to evaluation to avoid
274 * the access being replaced by a possible known value
275 * during the evaluation.
277 * If the access expression has any arguments (after evaluation
278 * in the context of "pc"), then we ignore it, since we cannot
279 * tell which elements are definitely killed.
281 * Otherwise, we extend the index expression to the dimension
282 * of the accessed array and intersect with the extent of the array and
283 * add a kill expression that kills these array elements is added to "scop".
285 static struct pet_scop *scop_add_kill(struct pet_scop *scop,
286 __isl_take pet_expr *expr, __isl_take pet_loc *loc,
287 __isl_keep pet_context *pc, struct pet_state *state)
289 int dim1, dim2;
290 isl_id *id;
291 isl_multi_pw_aff *index;
292 isl_map *map;
293 pet_expr *kill;
294 struct pet_array *array;
295 struct pet_scop *scop_i;
297 expr = pet_expr_access_set_write(expr, 1);
298 expr = pet_context_evaluate_expr(pc, expr);
299 if (!expr)
300 goto error;
301 if (expr->n_arg != 0) {
302 pet_loc_free(loc);
303 pet_expr_free(expr);
304 return scop;
306 array = extract_array(expr, pc, state);
307 if (!array)
308 goto error;
309 index = pet_expr_access_get_index(expr);
310 pet_expr_free(expr);
311 map = isl_map_from_multi_pw_aff(isl_multi_pw_aff_copy(index));
312 id = isl_map_get_tuple_id(map, isl_dim_out);
313 dim1 = isl_set_dim(array->extent, isl_dim_set);
314 dim2 = isl_map_dim(map, isl_dim_out);
315 map = isl_map_add_dims(map, isl_dim_out, dim1 - dim2);
316 map = isl_map_set_tuple_id(map, isl_dim_out, id);
317 map = isl_map_intersect_range(map, isl_set_copy(array->extent));
318 pet_array_free(array);
319 kill = pet_expr_kill_from_access_and_index(map, index);
320 scop_i = scop_from_evaluated_expr(kill, state->n_stmt++, loc, pc);
321 scop = pet_scop_add_par(state->ctx, scop, scop_i);
323 return scop;
324 error:
325 pet_expr_free(expr);
326 pet_loc_free(loc);
327 return pet_scop_free(scop);
330 /* For each argument of the __pencil_kill call in "tree" that
331 * represents an access, add a kill statement to "scop" killing the accessed
332 * elements.
334 static struct pet_scop *scop_from_pencil_kill(__isl_keep pet_tree *tree,
335 __isl_keep pet_context *pc, struct pet_state *state)
337 pet_expr *call;
338 struct pet_scop *scop;
339 int i, n;
341 call = tree->u.e.expr;
343 scop = pet_scop_empty(pet_context_get_space(pc));
345 n = pet_expr_get_n_arg(call);
346 for (i = 0; i < n; ++i) {
347 pet_expr *arg;
348 pet_loc *loc;
350 arg = pet_expr_get_arg(call, i);
351 if (!arg)
352 return pet_scop_free(scop);
353 if (pet_expr_get_type(arg) != pet_expr_access) {
354 pet_expr_free(arg);
355 continue;
357 loc = pet_tree_get_loc(tree);
358 scop = scop_add_kill(scop, arg, loc, pc, state);
361 return scop;
364 /* Construct a pet_scop for an expression statement within the context "pc".
366 * If the expression calls __pencil_kill, then it needs to be converted
367 * into zero or more kill statements.
368 * Otherwise, a scop is extracted directly from the tree.
370 static struct pet_scop *scop_from_tree_expr(__isl_keep pet_tree *tree,
371 __isl_keep pet_context *pc, struct pet_state *state)
373 int is_kill;
375 is_kill = is_pencil_kill(tree);
376 if (is_kill < 0)
377 return NULL;
378 if (is_kill)
379 return scop_from_pencil_kill(tree, pc, state);
380 return scop_from_unevaluated_tree(pet_tree_copy(tree),
381 state->n_stmt++, pc);
384 /* Return those elements in the space of "cond" that come after
385 * (based on "sign") an element in "cond" in the final dimension.
387 static __isl_give isl_set *after(__isl_take isl_set *cond, int sign)
389 isl_space *space;
390 isl_map *previous_to_this;
391 int i, dim;
393 dim = isl_set_dim(cond, isl_dim_set);
394 space = isl_space_map_from_set(isl_set_get_space(cond));
395 previous_to_this = isl_map_universe(space);
396 for (i = 0; i + 1 < dim; ++i)
397 previous_to_this = isl_map_equate(previous_to_this,
398 isl_dim_in, i, isl_dim_out, i);
399 if (sign > 0)
400 previous_to_this = isl_map_order_lt(previous_to_this,
401 isl_dim_in, dim - 1, isl_dim_out, dim - 1);
402 else
403 previous_to_this = isl_map_order_gt(previous_to_this,
404 isl_dim_in, dim - 1, isl_dim_out, dim - 1);
406 cond = isl_set_apply(cond, previous_to_this);
408 return cond;
411 /* Remove those iterations of "domain" that have an earlier iteration
412 * (based on "sign") in the final dimension where "skip" is satisfied.
413 * If "apply_skip_map" is set, then "skip_map" is first applied
414 * to the embedded skip condition before removing it from the domain.
416 static __isl_give isl_set *apply_affine_break(__isl_take isl_set *domain,
417 __isl_take isl_set *skip, int sign,
418 int apply_skip_map, __isl_keep isl_map *skip_map)
420 if (apply_skip_map)
421 skip = isl_set_apply(skip, isl_map_copy(skip_map));
422 skip = isl_set_intersect(skip , isl_set_copy(domain));
423 return isl_set_subtract(domain, after(skip, sign));
426 /* Create a single-dimensional multi-affine expression on the domain space
427 * of "pc" that is equal to the final dimension of this domain.
428 * "loop_nr" is the sequence number of the corresponding loop.
429 * If "id" is not NULL, then it is used as the output tuple name.
430 * Otherwise, the name is constructed as L_<loop_nr>.
432 static __isl_give isl_multi_aff *map_to_last(__isl_keep pet_context *pc,
433 int loop_nr, __isl_keep isl_id *id)
435 int pos;
436 isl_space *space;
437 isl_local_space *ls;
438 isl_aff *aff;
439 isl_multi_aff *ma;
440 char name[50];
441 isl_id *label;
443 space = pet_context_get_space(pc);
444 pos = isl_space_dim(space, isl_dim_set) - 1;
445 ls = isl_local_space_from_space(space);
446 aff = isl_aff_var_on_domain(ls, isl_dim_set, pos);
447 ma = isl_multi_aff_from_aff(aff);
449 if (id) {
450 label = isl_id_copy(id);
451 } else {
452 snprintf(name, sizeof(name), "L_%d", loop_nr);
453 label = isl_id_alloc(pet_context_get_ctx(pc), name, NULL);
455 ma = isl_multi_aff_set_tuple_id(ma, isl_dim_out, label);
457 return ma;
460 /* Create an affine expression that maps elements
461 * of an array "id_test" to the previous element in the final dimension
462 * (according to "inc"), provided this element belongs to "domain".
463 * That is, create the affine expression
465 * { id[outer,x] -> id[outer,x - inc] : (outer,x - inc) in domain }
467 static __isl_give isl_multi_pw_aff *map_to_previous(__isl_take isl_id *id_test,
468 __isl_take isl_set *domain, __isl_take isl_val *inc)
470 int pos;
471 isl_space *space;
472 isl_aff *aff;
473 isl_pw_aff *pa;
474 isl_multi_aff *ma;
475 isl_multi_pw_aff *prev;
477 pos = isl_set_dim(domain, isl_dim_set) - 1;
478 space = isl_set_get_space(domain);
479 space = isl_space_map_from_set(space);
480 ma = isl_multi_aff_identity(space);
481 aff = isl_multi_aff_get_aff(ma, pos);
482 aff = isl_aff_add_constant_val(aff, isl_val_neg(inc));
483 ma = isl_multi_aff_set_aff(ma, pos, aff);
484 domain = isl_set_preimage_multi_aff(domain, isl_multi_aff_copy(ma));
485 prev = isl_multi_pw_aff_from_multi_aff(ma);
486 pa = isl_multi_pw_aff_get_pw_aff(prev, pos);
487 pa = isl_pw_aff_intersect_domain(pa, domain);
488 prev = isl_multi_pw_aff_set_pw_aff(prev, pos, pa);
489 prev = isl_multi_pw_aff_set_tuple_id(prev, isl_dim_out, id_test);
491 return prev;
494 /* Add an implication to "scop" expressing that if an element of
495 * virtual array "id_test" has value "satisfied" then all previous elements
496 * of this array (in the final dimension) also have that value.
497 * The set of previous elements is bounded by "domain".
498 * If "sign" is negative then the iterator
499 * is decreasing and we express that all subsequent array elements
500 * (but still defined previously) have the same value.
502 static struct pet_scop *add_implication(struct pet_scop *scop,
503 __isl_take isl_id *id_test, __isl_take isl_set *domain, int sign,
504 int satisfied)
506 int i, dim;
507 isl_space *space;
508 isl_map *map;
510 dim = isl_set_dim(domain, isl_dim_set);
511 domain = isl_set_set_tuple_id(domain, id_test);
512 space = isl_space_map_from_set(isl_set_get_space(domain));
513 map = isl_map_universe(space);
514 for (i = 0; i + 1 < dim; ++i)
515 map = isl_map_equate(map, isl_dim_in, i, isl_dim_out, i);
516 if (sign > 0)
517 map = isl_map_order_ge(map,
518 isl_dim_in, dim - 1, isl_dim_out, dim - 1);
519 else
520 map = isl_map_order_le(map,
521 isl_dim_in, dim - 1, isl_dim_out, dim - 1);
522 map = isl_map_intersect_range(map, domain);
523 scop = pet_scop_add_implication(scop, map, satisfied);
525 return scop;
528 /* Add a filter to "scop" that imposes that it is only executed
529 * when the variable identified by "id_test" has a zero value
530 * for all previous iterations of "domain".
532 * In particular, add a filter that imposes that the array
533 * has a zero value at the previous iteration of domain and
534 * add an implication that implies that it then has that
535 * value for all previous iterations.
537 static struct pet_scop *scop_add_break(struct pet_scop *scop,
538 __isl_take isl_id *id_test, __isl_take isl_set *domain,
539 __isl_take isl_val *inc)
541 isl_multi_pw_aff *prev;
542 int sign = isl_val_sgn(inc);
544 prev = map_to_previous(isl_id_copy(id_test), isl_set_copy(domain), inc);
545 scop = add_implication(scop, id_test, domain, sign, 0);
546 scop = pet_scop_filter(scop, prev, 0);
548 return scop;
551 static struct pet_scop *scop_from_tree(__isl_keep pet_tree *tree,
552 __isl_keep pet_context *pc, struct pet_state *state);
554 /* Construct a pet_scop for an infinite loop around the given body
555 * within the context "pc".
556 * "loop_id" is the label on the loop or NULL if there is no such label.
558 * The domain of "pc" has already been extended with an infinite loop
560 * { [t] : t >= 0 }
562 * We extract a pet_scop for the body and then embed it in a loop with
563 * schedule
565 * { [outer,t] -> [t] }
567 * If the body contains any break, then it is taken into
568 * account in apply_affine_break (if the skip condition is affine)
569 * or in scop_add_break (if the skip condition is not affine).
571 * Note that in case of an affine skip condition,
572 * since we are dealing with a loop without loop iterator,
573 * the skip condition cannot refer to the current loop iterator and
574 * so effectively, the effect on the iteration domain is of the form
576 * { [outer,0]; [outer,t] : t >= 1 and not skip }
578 static struct pet_scop *scop_from_infinite_loop(__isl_keep pet_tree *body,
579 __isl_keep isl_id *loop_id, __isl_keep pet_context *pc,
580 struct pet_state *state)
582 isl_ctx *ctx;
583 isl_id *id_test;
584 isl_set *domain;
585 isl_set *skip;
586 isl_multi_aff *sched;
587 struct pet_scop *scop;
588 int has_affine_break;
589 int has_var_break;
591 ctx = pet_tree_get_ctx(body);
592 domain = pet_context_get_domain(pc);
593 sched = map_to_last(pc, state->n_loop++, loop_id);
595 scop = scop_from_tree(body, pc, state);
597 has_affine_break = pet_scop_has_affine_skip(scop, pet_skip_later);
598 if (has_affine_break)
599 skip = pet_scop_get_affine_skip_domain(scop, pet_skip_later);
600 has_var_break = pet_scop_has_var_skip(scop, pet_skip_later);
601 if (has_var_break)
602 id_test = pet_scop_get_skip_id(scop, pet_skip_later);
604 scop = pet_scop_reset_skips(scop);
605 scop = pet_scop_embed(scop, isl_set_copy(domain), sched);
606 if (has_affine_break) {
607 domain = apply_affine_break(domain, skip, 1, 0, NULL);
608 scop = pet_scop_intersect_domain_prefix(scop,
609 isl_set_copy(domain));
611 if (has_var_break)
612 scop = scop_add_break(scop, id_test, domain, isl_val_one(ctx));
613 else
614 isl_set_free(domain);
616 return scop;
619 /* Construct a pet_scop for an infinite loop, i.e., a loop of the form
621 * for (;;)
622 * body
624 * within the context "pc".
626 * Extend the domain of "pc" with an extra inner loop
628 * { [t] : t >= 0 }
630 * and construct the scop in scop_from_infinite_loop.
632 static struct pet_scop *scop_from_infinite_for(__isl_keep pet_tree *tree,
633 __isl_keep pet_context *pc, struct pet_state *state)
635 struct pet_scop *scop;
637 pc = pet_context_copy(pc);
638 pc = pet_context_clear_writes_in_tree(pc, tree->u.l.body);
640 pc = pet_context_add_infinite_loop(pc);
642 scop = scop_from_infinite_loop(tree->u.l.body, tree->label, pc, state);
644 pet_context_free(pc);
646 return scop;
649 /* Construct a pet_scop for a while loop of the form
651 * while (pa)
652 * body
654 * within the context "pc".
656 * The domain of "pc" has already been extended with an infinite loop
658 * { [t] : t >= 0 }
660 * Here, we add the constraints on the outer loop iterators
661 * implied by "pa" and construct the scop in scop_from_infinite_loop.
662 * Note that the intersection with these constraints
663 * may result in an empty loop.
665 static struct pet_scop *scop_from_affine_while(__isl_keep pet_tree *tree,
666 __isl_take isl_pw_aff *pa, __isl_take pet_context *pc,
667 struct pet_state *state)
669 struct pet_scop *scop;
670 isl_set *dom, *local;
671 isl_set *valid;
673 valid = isl_pw_aff_domain(isl_pw_aff_copy(pa));
674 dom = isl_pw_aff_non_zero_set(pa);
675 local = isl_set_add_dims(isl_set_copy(dom), isl_dim_set, 1);
676 pc = pet_context_intersect_domain(pc, local);
677 scop = scop_from_infinite_loop(tree->u.l.body, tree->label, pc, state);
678 scop = pet_scop_restrict(scop, dom);
679 scop = pet_scop_restrict_context(scop, valid);
681 pet_context_free(pc);
682 return scop;
685 /* Construct a scop for a while, given the scops for the condition
686 * and the body, the filter identifier and the iteration domain of
687 * the while loop.
689 * In particular, the scop for the condition is filtered to depend
690 * on "id_test" evaluating to true for all previous iterations
691 * of the loop, while the scop for the body is filtered to depend
692 * on "id_test" evaluating to true for all iterations up to the
693 * current iteration.
694 * The actual filter only imposes that this virtual array has
695 * value one on the previous or the current iteration.
696 * The fact that this condition also applies to the previous
697 * iterations is enforced by an implication.
699 * These filtered scops are then combined into a single scop,
700 * with the condition scop scheduled before the body scop.
702 * "sign" is positive if the iterator increases and negative
703 * if it decreases.
705 static struct pet_scop *scop_add_while(struct pet_scop *scop_cond,
706 struct pet_scop *scop_body, __isl_take isl_id *id_test,
707 __isl_take isl_set *domain, __isl_take isl_val *inc)
709 isl_ctx *ctx = isl_set_get_ctx(domain);
710 isl_space *space;
711 isl_multi_pw_aff *test_index;
712 isl_multi_pw_aff *prev;
713 int sign = isl_val_sgn(inc);
714 struct pet_scop *scop;
716 prev = map_to_previous(isl_id_copy(id_test), isl_set_copy(domain), inc);
717 scop_cond = pet_scop_filter(scop_cond, prev, 1);
719 space = isl_space_map_from_set(isl_set_get_space(domain));
720 test_index = isl_multi_pw_aff_identity(space);
721 test_index = isl_multi_pw_aff_set_tuple_id(test_index, isl_dim_out,
722 isl_id_copy(id_test));
723 scop_body = pet_scop_filter(scop_body, test_index, 1);
725 scop = pet_scop_add_seq(ctx, scop_cond, scop_body);
726 scop = add_implication(scop, id_test, domain, sign, 1);
728 return scop;
731 /* Create a pet_scop with a single statement with name S_<stmt_nr>,
732 * evaluating "cond" and writing the result to a virtual scalar,
733 * as expressed by "index".
734 * The expression "cond" has not yet been evaluated in the context of "pc".
735 * Do so within the context "pc".
736 * The location of the statement is set to "loc".
738 static struct pet_scop *scop_from_non_affine_condition(
739 __isl_take pet_expr *cond, int stmt_nr,
740 __isl_take isl_multi_pw_aff *index,
741 __isl_take pet_loc *loc, __isl_keep pet_context *pc)
743 pet_expr *expr, *write;
745 cond = pet_context_evaluate_expr(pc, cond);
747 write = pet_expr_from_index(index);
748 write = pet_expr_access_set_write(write, 1);
749 write = pet_expr_access_set_read(write, 0);
750 expr = pet_expr_new_binary(1, pet_op_assign, write, cond);
752 return scop_from_evaluated_expr(expr, stmt_nr, loc, pc);
755 /* Given that "scop" has an affine skip condition of type pet_skip_now,
756 * apply this skip condition to the domain of "pc".
757 * That is, remove the elements satisfying the skip condition from
758 * the domain of "pc".
760 static __isl_give pet_context *apply_affine_continue(__isl_take pet_context *pc,
761 struct pet_scop *scop)
763 isl_set *domain, *skip;
765 skip = pet_scop_get_affine_skip_domain(scop, pet_skip_now);
766 domain = pet_context_get_domain(pc);
767 domain = isl_set_subtract(domain, skip);
768 pc = pet_context_intersect_domain(pc, domain);
770 return pc;
773 /* Add a scop for evaluating the loop increment "inc" at the end
774 * of a loop body "scop" within the context "pc".
776 * The skip conditions resulting from continue statements inside
777 * the body do not apply to "inc", but those resulting from break
778 * statements do need to get applied.
780 static struct pet_scop *scop_add_inc(struct pet_scop *scop,
781 __isl_take pet_expr *inc, __isl_take pet_loc *loc,
782 __isl_keep pet_context *pc, struct pet_state *state)
784 struct pet_scop *scop_inc;
786 pc = pet_context_copy(pc);
788 if (pet_scop_has_skip(scop, pet_skip_later)) {
789 isl_multi_pw_aff *skip;
790 skip = pet_scop_get_skip(scop, pet_skip_later);
791 scop = pet_scop_set_skip(scop, pet_skip_now, skip);
792 if (pet_scop_has_affine_skip(scop, pet_skip_now))
793 pc = apply_affine_continue(pc, scop);
794 } else
795 pet_scop_reset_skip(scop, pet_skip_now);
796 scop_inc = scop_from_expr(inc, state->n_stmt++, loc, pc);
797 scop = pet_scop_add_seq(state->ctx, scop, scop_inc);
799 pet_context_free(pc);
801 return scop;
804 /* Construct a generic while scop, with iteration domain
805 * { [t] : t >= 0 } around the scop for "tree_body" within the context "pc".
806 * "loop_id" is the label on the loop or NULL if there is no such label.
807 * The domain of "pc" has already been extended with this infinite loop
809 * { [t] : t >= 0 }
811 * The scop consists of two parts,
812 * one for evaluating the condition "cond" and one for the body.
813 * If "expr_inc" is not NULL, then a scop for evaluating this expression
814 * is added at the end of the body,
815 * after replacing any skip conditions resulting from continue statements
816 * by the skip conditions resulting from break statements (if any).
818 * The schedules are combined as a sequence to reflect that the condition is
819 * evaluated before the body is executed and the body is filtered to depend
820 * on the result of the condition evaluating to true on all iterations
821 * up to the current iteration, while the evaluation of the condition itself
822 * is filtered to depend on the result of the condition evaluating to true
823 * on all previous iterations.
824 * The context of the scop representing the body is dropped
825 * because we don't know how many times the body will be executed,
826 * if at all.
828 * If the body contains any break, then it is taken into
829 * account in apply_affine_break (if the skip condition is affine)
830 * or in scop_add_break (if the skip condition is not affine).
832 * Note that in case of an affine skip condition,
833 * since we are dealing with a loop without loop iterator,
834 * the skip condition cannot refer to the current loop iterator and
835 * so effectively, the effect on the iteration domain is of the form
837 * { [outer,0]; [outer,t] : t >= 1 and not skip }
839 static struct pet_scop *scop_from_non_affine_while(__isl_take pet_expr *cond,
840 __isl_take pet_loc *loc, __isl_keep pet_tree *tree_body,
841 __isl_keep isl_id *loop_id, __isl_take pet_expr *expr_inc,
842 __isl_take pet_context *pc, struct pet_state *state)
844 isl_ctx *ctx;
845 isl_id *id_test, *id_break_test;
846 isl_space *space;
847 isl_multi_pw_aff *test_index;
848 isl_set *domain;
849 isl_set *skip;
850 isl_multi_aff *sched;
851 struct pet_scop *scop, *scop_body;
852 int has_affine_break;
853 int has_var_break;
855 ctx = state->ctx;
856 space = pet_context_get_space(pc);
857 test_index = pet_create_test_index(space, state->n_test++);
858 scop = scop_from_non_affine_condition(cond, state->n_stmt++,
859 isl_multi_pw_aff_copy(test_index),
860 pet_loc_copy(loc), pc);
861 id_test = isl_multi_pw_aff_get_tuple_id(test_index, isl_dim_out);
862 domain = pet_context_get_domain(pc);
863 scop = pet_scop_add_boolean_array(scop, isl_set_copy(domain),
864 test_index, state->int_size);
866 sched = map_to_last(pc, state->n_loop++, loop_id);
868 scop_body = scop_from_tree(tree_body, pc, state);
870 has_affine_break = pet_scop_has_affine_skip(scop_body, pet_skip_later);
871 if (has_affine_break)
872 skip = pet_scop_get_affine_skip_domain(scop_body,
873 pet_skip_later);
874 has_var_break = pet_scop_has_var_skip(scop_body, pet_skip_later);
875 if (has_var_break)
876 id_break_test = pet_scop_get_skip_id(scop_body, pet_skip_later);
878 scop_body = pet_scop_reset_context(scop_body);
879 if (expr_inc)
880 scop_body = scop_add_inc(scop_body, expr_inc, loc, pc, state);
881 else
882 pet_loc_free(loc);
883 scop_body = pet_scop_reset_skips(scop_body);
885 if (has_affine_break) {
886 domain = apply_affine_break(domain, skip, 1, 0, NULL);
887 scop = pet_scop_intersect_domain_prefix(scop,
888 isl_set_copy(domain));
889 scop_body = pet_scop_intersect_domain_prefix(scop_body,
890 isl_set_copy(domain));
892 if (has_var_break) {
893 scop = scop_add_break(scop, isl_id_copy(id_break_test),
894 isl_set_copy(domain), isl_val_one(ctx));
895 scop_body = scop_add_break(scop_body, id_break_test,
896 isl_set_copy(domain), isl_val_one(ctx));
898 scop = scop_add_while(scop, scop_body, id_test, isl_set_copy(domain),
899 isl_val_one(ctx));
901 scop = pet_scop_embed(scop, domain, sched);
903 pet_context_free(pc);
904 return scop;
907 /* Check if the while loop is of the form
909 * while (affine expression)
910 * body
912 * If so, call scop_from_affine_while to construct a scop.
914 * Otherwise, pass control to scop_from_non_affine_while.
916 * "pc" is the context in which the affine expressions in the scop are created.
917 * The domain of "pc" is extended with an infinite loop
919 * { [t] : t >= 0 }
921 * before passing control to scop_from_affine_while or
922 * scop_from_non_affine_while.
924 static struct pet_scop *scop_from_while(__isl_keep pet_tree *tree,
925 __isl_keep pet_context *pc, struct pet_state *state)
927 pet_expr *cond_expr;
928 isl_pw_aff *pa;
930 if (!tree)
931 return NULL;
933 pc = pet_context_copy(pc);
934 pc = pet_context_clear_writes_in_tree(pc, tree->u.l.body);
936 cond_expr = pet_expr_copy(tree->u.l.cond);
937 cond_expr = pet_context_evaluate_expr(pc, cond_expr);
938 pa = pet_expr_extract_affine_condition(cond_expr, pc);
939 pet_expr_free(cond_expr);
941 pc = pet_context_add_infinite_loop(pc);
943 if (!pa)
944 goto error;
946 if (!isl_pw_aff_involves_nan(pa))
947 return scop_from_affine_while(tree, pa, pc, state);
948 isl_pw_aff_free(pa);
949 return scop_from_non_affine_while(pet_expr_copy(tree->u.l.cond),
950 pet_tree_get_loc(tree), tree->u.l.body,
951 tree->label, NULL, pc, state);
952 error:
953 pet_context_free(pc);
954 return NULL;
957 /* Check whether "cond" expresses a simple loop bound
958 * on the final set dimension.
959 * In particular, if "up" is set then "cond" should contain only
960 * upper bounds on the final set dimension.
961 * Otherwise, it should contain only lower bounds.
963 static int is_simple_bound(__isl_keep isl_set *cond, __isl_keep isl_val *inc)
965 int pos;
967 pos = isl_set_dim(cond, isl_dim_set) - 1;
968 if (isl_val_is_pos(inc))
969 return !isl_set_dim_has_any_lower_bound(cond, isl_dim_set, pos);
970 else
971 return !isl_set_dim_has_any_upper_bound(cond, isl_dim_set, pos);
974 /* Extend a condition on a given iteration of a loop to one that
975 * imposes the same condition on all previous iterations.
976 * "domain" expresses the lower [upper] bound on the iterations
977 * when inc is positive [negative] in its final dimension.
979 * In particular, we construct the condition (when inc is positive)
981 * forall i' : (domain(i') and i' <= i) => cond(i')
983 * (where "<=" applies to the final dimension)
984 * which is equivalent to
986 * not exists i' : domain(i') and i' <= i and not cond(i')
988 * We construct this set by subtracting the satisfying cond from domain,
989 * applying a map
991 * { [i'] -> [i] : i' <= i }
993 * and then subtracting the result from domain again.
995 static __isl_give isl_set *valid_for_each_iteration(__isl_take isl_set *cond,
996 __isl_take isl_set *domain, __isl_take isl_val *inc)
998 isl_space *space;
999 isl_map *previous_to_this;
1000 int i, dim;
1002 dim = isl_set_dim(cond, isl_dim_set);
1003 space = isl_space_map_from_set(isl_set_get_space(cond));
1004 previous_to_this = isl_map_universe(space);
1005 for (i = 0; i + 1 < dim; ++i)
1006 previous_to_this = isl_map_equate(previous_to_this,
1007 isl_dim_in, i, isl_dim_out, i);
1008 if (isl_val_is_pos(inc))
1009 previous_to_this = isl_map_order_le(previous_to_this,
1010 isl_dim_in, dim - 1, isl_dim_out, dim - 1);
1011 else
1012 previous_to_this = isl_map_order_ge(previous_to_this,
1013 isl_dim_in, dim - 1, isl_dim_out, dim - 1);
1015 cond = isl_set_subtract(isl_set_copy(domain), cond);
1016 cond = isl_set_apply(cond, previous_to_this);
1017 cond = isl_set_subtract(domain, cond);
1019 isl_val_free(inc);
1021 return cond;
1024 /* Given an initial value of the form
1026 * { [outer,i] -> init(outer) }
1028 * construct a domain of the form
1030 * { [outer,i] : exists a: i = init(outer) + a * inc and a >= 0 }
1032 static __isl_give isl_set *strided_domain(__isl_take isl_pw_aff *init,
1033 __isl_take isl_val *inc)
1035 int dim;
1036 isl_aff *aff;
1037 isl_space *space;
1038 isl_local_space *ls;
1039 isl_set *set;
1041 dim = isl_pw_aff_dim(init, isl_dim_in);
1043 init = isl_pw_aff_add_dims(init, isl_dim_in, 1);
1044 space = isl_pw_aff_get_domain_space(init);
1045 ls = isl_local_space_from_space(space);
1046 aff = isl_aff_zero_on_domain(isl_local_space_copy(ls));
1047 aff = isl_aff_add_coefficient_val(aff, isl_dim_in, dim, inc);
1048 init = isl_pw_aff_add(init, isl_pw_aff_from_aff(aff));
1050 aff = isl_aff_var_on_domain(ls, isl_dim_set, dim - 1);
1051 set = isl_pw_aff_eq_set(isl_pw_aff_from_aff(aff), init);
1053 set = isl_set_lower_bound_si(set, isl_dim_set, dim, 0);
1054 set = isl_set_project_out(set, isl_dim_set, dim, 1);
1056 return set;
1059 /* Assuming "cond" represents a bound on a loop where the loop
1060 * iterator "iv" is incremented (or decremented) by one, check if wrapping
1061 * is possible.
1063 * Under the given assumptions, wrapping is only possible if "cond" allows
1064 * for the last value before wrapping, i.e., 2^width - 1 in case of an
1065 * increasing iterator and 0 in case of a decreasing iterator.
1067 static int can_wrap(__isl_keep isl_set *cond, __isl_keep pet_expr *iv,
1068 __isl_keep isl_val *inc)
1070 int cw;
1071 isl_ctx *ctx;
1072 isl_val *limit;
1073 isl_set *test;
1075 test = isl_set_copy(cond);
1077 ctx = isl_set_get_ctx(test);
1078 if (isl_val_is_neg(inc))
1079 limit = isl_val_zero(ctx);
1080 else {
1081 limit = isl_val_int_from_ui(ctx, pet_expr_get_type_size(iv));
1082 limit = isl_val_2exp(limit);
1083 limit = isl_val_sub_ui(limit, 1);
1086 test = isl_set_fix_val(cond, isl_dim_set, 0, limit);
1087 cw = !isl_set_is_empty(test);
1088 isl_set_free(test);
1090 return cw;
1093 /* Given a space
1095 * { [outer, v] },
1097 * construct the following affine expression on this space
1099 * { [outer, v] -> [outer, v mod 2^width] }
1101 * where width is the number of bits used to represent the values
1102 * of the unsigned variable "iv".
1104 static __isl_give isl_multi_aff *compute_wrapping(__isl_take isl_space *space,
1105 __isl_keep pet_expr *iv)
1107 int dim;
1108 isl_aff *aff;
1109 isl_multi_aff *ma;
1111 dim = isl_space_dim(space, isl_dim_set);
1113 space = isl_space_map_from_set(space);
1114 ma = isl_multi_aff_identity(space);
1116 aff = isl_multi_aff_get_aff(ma, dim - 1);
1117 aff = pet_wrap_aff(aff, pet_expr_get_type_size(iv));
1118 ma = isl_multi_aff_set_aff(ma, dim - 1, aff);
1120 return ma;
1123 /* Given two sets in the space
1125 * { [l,i] },
1127 * where l represents the outer loop iterators, compute the set
1128 * of values of l that ensure that "set1" is a subset of "set2".
1130 * set1 is a subset of set2 if
1132 * forall i: set1(l,i) => set2(l,i)
1134 * or
1136 * not exists i: set1(l,i) and not set2(l,i)
1138 * i.e.,
1140 * not exists i: (set1 \ set2)(l,i)
1142 static __isl_give isl_set *enforce_subset(__isl_take isl_set *set1,
1143 __isl_take isl_set *set2)
1145 int pos;
1147 pos = isl_set_dim(set1, isl_dim_set) - 1;
1148 set1 = isl_set_subtract(set1, set2);
1149 set1 = isl_set_eliminate(set1, isl_dim_set, pos, 1);
1150 return isl_set_complement(set1);
1153 /* Compute the set of outer iterator values for which "cond" holds
1154 * on the next iteration of the inner loop for each element of "dom".
1156 * We first construct mapping { [l,i] -> [l,i + inc] } (where l refers
1157 * to the outer loop iterators), plug that into "cond"
1158 * and then compute the set of outer iterators for which "dom" is a subset
1159 * of the result.
1161 static __isl_give isl_set *valid_on_next(__isl_take isl_set *cond,
1162 __isl_take isl_set *dom, __isl_take isl_val *inc)
1164 int pos;
1165 isl_space *space;
1166 isl_aff *aff;
1167 isl_multi_aff *ma;
1169 pos = isl_set_dim(dom, isl_dim_set) - 1;
1170 space = isl_set_get_space(dom);
1171 space = isl_space_map_from_set(space);
1172 ma = isl_multi_aff_identity(space);
1173 aff = isl_multi_aff_get_aff(ma, pos);
1174 aff = isl_aff_add_constant_val(aff, inc);
1175 ma = isl_multi_aff_set_aff(ma, pos, aff);
1176 cond = isl_set_preimage_multi_aff(cond, ma);
1178 return enforce_subset(dom, cond);
1181 /* Construct a pet_scop for the initialization of the iterator
1182 * of the for loop "tree" within the context "pc" (i.e., the context
1183 * of the loop).
1185 static __isl_give pet_scop *scop_from_for_init(__isl_keep pet_tree *tree,
1186 __isl_keep pet_context *pc, struct pet_state *state)
1188 pet_expr *expr_iv, *init;
1189 int type_size;
1191 expr_iv = pet_expr_copy(tree->u.l.iv);
1192 type_size = pet_expr_get_type_size(expr_iv);
1193 init = pet_expr_copy(tree->u.l.init);
1194 init = pet_expr_new_binary(type_size, pet_op_assign, expr_iv, init);
1195 return scop_from_expr(init, state->n_stmt++,
1196 pet_tree_get_loc(tree), pc);
1199 /* Extract the for loop "tree" as a while loop within the context "pc_init".
1200 * In particular, "pc_init" represents the context of the loop,
1201 * whereas "pc" represents the context of the body of the loop and
1202 * has already had its domain extended with an infinite loop
1204 * { [t] : t >= 0 }
1206 * The for loop has the form
1208 * for (iv = init; cond; iv += inc)
1209 * body;
1211 * and is treated as
1213 * iv = init;
1214 * while (cond) {
1215 * body;
1216 * iv += inc;
1219 * except that the skips resulting from any continue statements
1220 * in body do not apply to the increment, but are replaced by the skips
1221 * resulting from break statements.
1223 * If the loop iterator is declared in the for loop, then it is killed before
1224 * and after the loop.
1226 static struct pet_scop *scop_from_non_affine_for(__isl_keep pet_tree *tree,
1227 __isl_keep pet_context *pc_init, __isl_take pet_context *pc,
1228 struct pet_state *state)
1230 int declared;
1231 isl_id *iv;
1232 pet_expr *expr_iv, *inc;
1233 struct pet_scop *scop_init, *scop;
1234 int type_size;
1235 struct pet_array *array;
1236 struct pet_scop *scop_kill;
1238 iv = pet_expr_access_get_id(tree->u.l.iv);
1239 pc = pet_context_clear_value(pc, iv);
1241 declared = tree->u.l.declared;
1243 scop_init = scop_from_for_init(tree, pc_init, state);
1245 expr_iv = pet_expr_copy(tree->u.l.iv);
1246 type_size = pet_expr_get_type_size(expr_iv);
1247 inc = pet_expr_copy(tree->u.l.inc);
1248 inc = pet_expr_new_binary(type_size, pet_op_add_assign, expr_iv, inc);
1250 scop = scop_from_non_affine_while(pet_expr_copy(tree->u.l.cond),
1251 pet_tree_get_loc(tree), tree->u.l.body, tree->label,
1252 inc, pet_context_copy(pc), state);
1254 scop = pet_scop_add_seq(state->ctx, scop_init, scop);
1256 pet_context_free(pc);
1258 if (!declared)
1259 return scop;
1261 array = extract_array(tree->u.l.iv, pc_init, state);
1262 if (array)
1263 array->declared = 1;
1264 scop_kill = kill(pet_tree_get_loc(tree), array, pc_init, state);
1265 scop = pet_scop_add_seq(state->ctx, scop_kill, scop);
1266 scop_kill = kill(pet_tree_get_loc(tree), array, pc_init, state);
1267 scop_kill = pet_scop_add_array(scop_kill, array);
1268 scop = pet_scop_add_seq(state->ctx, scop, scop_kill);
1270 return scop;
1273 /* Given an access expression "expr", is the variable accessed by
1274 * "expr" assigned anywhere inside "tree"?
1276 static int is_assigned(__isl_keep pet_expr *expr, __isl_keep pet_tree *tree)
1278 int assigned = 0;
1279 isl_id *id;
1281 id = pet_expr_access_get_id(expr);
1282 assigned = pet_tree_writes(tree, id);
1283 isl_id_free(id);
1285 return assigned;
1288 /* Are all nested access parameters in "pa" allowed given "tree".
1289 * In particular, is none of them written by anywhere inside "tree".
1291 * If "tree" has any continue or break nodes in the current loop level,
1292 * then no nested access parameters are allowed.
1293 * In particular, if there is any nested access in a guard
1294 * for a piece of code containing a "continue", then we want to introduce
1295 * a separate statement for evaluating this guard so that we can express
1296 * that the result is false for all previous iterations.
1298 static int is_nested_allowed(__isl_keep isl_pw_aff *pa,
1299 __isl_keep pet_tree *tree)
1301 int i, nparam;
1303 if (!tree)
1304 return -1;
1306 if (!pet_nested_any_in_pw_aff(pa))
1307 return 1;
1309 if (pet_tree_has_continue_or_break(tree))
1310 return 0;
1312 nparam = isl_pw_aff_dim(pa, isl_dim_param);
1313 for (i = 0; i < nparam; ++i) {
1314 isl_id *id = isl_pw_aff_get_dim_id(pa, isl_dim_param, i);
1315 pet_expr *expr;
1316 int allowed;
1318 if (!pet_nested_in_id(id)) {
1319 isl_id_free(id);
1320 continue;
1323 expr = pet_nested_extract_expr(id);
1324 allowed = pet_expr_get_type(expr) == pet_expr_access &&
1325 !is_assigned(expr, tree);
1327 pet_expr_free(expr);
1328 isl_id_free(id);
1330 if (!allowed)
1331 return 0;
1334 return 1;
1337 /* Internal data structure for collect_local.
1338 * "pc" and "state" are needed to extract pet_arrays for the local variables.
1339 * "local" collects the results.
1341 struct pet_tree_collect_local_data {
1342 pet_context *pc;
1343 struct pet_state *state;
1344 isl_union_set *local;
1347 /* Add the variable accessed by "var" to data->local.
1348 * We extract a representation of the variable from
1349 * the pet_array constructed using extract_array
1350 * to ensure consistency with the rest of the scop.
1352 static int add_local(struct pet_tree_collect_local_data *data,
1353 __isl_keep pet_expr *var)
1355 struct pet_array *array;
1356 isl_set *universe;
1358 array = extract_array(var, data->pc, data->state);
1359 if (!array)
1360 return -1;
1362 universe = isl_set_universe(isl_set_get_space(array->extent));
1363 data->local = isl_union_set_add_set(data->local, universe);
1364 pet_array_free(array);
1366 return 0;
1369 /* If the node "tree" declares a variable, then add it to
1370 * data->local.
1372 static int extract_local_var(__isl_keep pet_tree *tree, void *user)
1374 enum pet_tree_type type;
1375 struct pet_tree_collect_local_data *data = user;
1377 type = pet_tree_get_type(tree);
1378 if (type == pet_tree_decl || type == pet_tree_decl_init)
1379 return add_local(data, tree->u.d.var);
1381 return 0;
1384 /* If the node "tree" is a for loop that declares its induction variable,
1385 * then add it this induction variable to data->local.
1387 static int extract_local_iterator(__isl_keep pet_tree *tree, void *user)
1389 struct pet_tree_collect_local_data *data = user;
1391 if (pet_tree_get_type(tree) == pet_tree_for && tree->u.l.declared)
1392 return add_local(data, tree->u.l.iv);
1394 return 0;
1397 /* Collect and return all local variables of the for loop represented
1398 * by "tree", with "scop" the corresponding pet_scop.
1399 * "pc" and "state" are needed to extract pet_arrays for the local variables.
1401 * We collect not only the variables that are declared inside "tree",
1402 * but also the loop iterators that are declared anywhere inside
1403 * any possible macro statements in "scop".
1404 * The latter also appear as declared variable in the scop,
1405 * whereas other declared loop iterators only appear implicitly
1406 * in the iteration domains.
1408 static __isl_give isl_union_set *collect_local(struct pet_scop *scop,
1409 __isl_keep pet_tree *tree, __isl_keep pet_context *pc,
1410 struct pet_state *state)
1412 int i;
1413 isl_ctx *ctx;
1414 struct pet_tree_collect_local_data data = { pc, state };
1416 ctx = pet_tree_get_ctx(tree);
1417 data.local = isl_union_set_empty(isl_space_params_alloc(ctx, 0));
1419 if (pet_tree_foreach_sub_tree(tree, &extract_local_var, &data) < 0)
1420 return isl_union_set_free(data.local);
1422 for (i = 0; i < scop->n_stmt; ++i) {
1423 pet_tree *body = scop->stmts[i]->body;
1424 if (pet_tree_foreach_sub_tree(body, &extract_local_iterator,
1425 &data) < 0)
1426 return isl_union_set_free(data.local);
1429 return data.local;
1432 /* Add an independence to "scop" if the for node "tree" was marked
1433 * independent.
1434 * "domain" is the set of loop iterators, with the current for loop
1435 * innermost. If "sign" is positive, then the inner iterator increases.
1436 * Otherwise it decreases.
1437 * "pc" and "state" are needed to extract pet_arrays for the local variables.
1439 * If the tree was marked, then collect all local variables and
1440 * add an independence.
1442 static struct pet_scop *set_independence(struct pet_scop *scop,
1443 __isl_keep pet_tree *tree, __isl_keep isl_set *domain, int sign,
1444 __isl_keep pet_context *pc, struct pet_state *state)
1446 isl_union_set *local;
1448 if (!tree->u.l.independent)
1449 return scop;
1451 local = collect_local(scop, tree, pc, state);
1452 scop = pet_scop_set_independent(scop, domain, local, sign);
1454 return scop;
1457 /* Add a scop for assigning to the variable corresponding to the loop
1458 * iterator the result of adding the increment to the loop iterator
1459 * at the end of a loop body "scop" within the context "pc".
1460 * "tree" represents the for loop.
1462 * The increment is of the form
1464 * iv = iv + inc
1466 * Note that "iv" on the right hand side will be evaluated in terms
1467 * of the (possibly virtual) loop iterator, i.e., the inner dimension
1468 * of the domain, while "iv" on the left hand side will not be evaluated
1469 * (because it is a write) and will continue to refer to the original
1470 * variable.
1472 static __isl_give pet_scop *add_iterator_assignment(__isl_take pet_scop *scop,
1473 __isl_keep pet_tree *tree, __isl_keep pet_context *pc,
1474 struct pet_state *state)
1476 int type_size;
1477 pet_expr *expr, *iv, *inc;
1479 iv = pet_expr_copy(tree->u.l.iv);
1480 type_size = pet_expr_get_type_size(iv);
1481 iv = pet_expr_access_set_write(iv, 0);
1482 iv = pet_expr_access_set_read(iv, 1);
1483 inc = pet_expr_copy(tree->u.l.inc);
1484 expr = pet_expr_new_binary(type_size, pet_op_add, iv, inc);
1485 iv = pet_expr_copy(tree->u.l.iv);
1486 expr = pet_expr_new_binary(type_size, pet_op_assign, iv, expr);
1488 scop = scop_add_inc(scop, expr, pet_tree_get_loc(tree), pc, state);
1490 return scop;
1493 /* Construct a pet_scop for a for tree with static affine initialization
1494 * and constant increment within the context "pc".
1495 * The domain of "pc" has already been extended with an (at this point
1496 * unbounded) inner loop iterator corresponding to the current for loop.
1498 * The condition is allowed to contain nested accesses, provided
1499 * they are not being written to inside the body of the loop.
1500 * Otherwise, or if the condition is otherwise non-affine, the for loop is
1501 * essentially treated as a while loop, with iteration domain
1502 * { [l,i] : i >= init }, where l refers to the outer loop iterators.
1504 * We extract a pet_scop for the body after intersecting the domain of "pc"
1506 * { [l,i] : i >= init and condition' }
1508 * or
1510 * { [l,i] : i <= init and condition' }
1512 * Where condition' is equal to condition if the latter is
1513 * a simple upper [lower] bound and a condition that is extended
1514 * to apply to all previous iterations otherwise.
1515 * Afterwards, the schedule of the pet_scop is extended with
1517 * { [l,i] -> [i] }
1519 * or
1521 * { [l,i] -> [-i] }
1523 * If the condition is non-affine, then we drop the condition from the
1524 * iteration domain and instead create a separate statement
1525 * for evaluating the condition. The body is then filtered to depend
1526 * on the result of the condition evaluating to true on all iterations
1527 * up to the current iteration, while the evaluation the condition itself
1528 * is filtered to depend on the result of the condition evaluating to true
1529 * on all previous iterations.
1530 * The context of the scop representing the body is dropped
1531 * because we don't know how many times the body will be executed,
1532 * if at all.
1534 * If the stride of the loop is not 1, then "i >= init" is replaced by
1536 * (exists a: i = init + stride * a and a >= 0)
1538 * If the loop iterator i is unsigned, then wrapping may occur.
1539 * We therefore use a virtual iterator instead that does not wrap.
1540 * However, the condition in the code applies
1541 * to the wrapped value, so we need to change condition(l,i)
1542 * into condition([l,i % 2^width]). Similarly, we replace all accesses
1543 * to the original iterator by the wrapping of the virtual iterator.
1544 * Note that there may be no need to perform this final wrapping
1545 * if the loop condition (after wrapping) satisfies certain conditions.
1546 * However, the is_simple_bound condition is not enough since it doesn't
1547 * check if there even is an upper bound.
1549 * Wrapping on unsigned iterators can be avoided entirely if
1550 * the loop condition is simple, the loop iterator is incremented
1551 * [decremented] by one and the last value before wrapping cannot
1552 * possibly satisfy the loop condition.
1554 * Valid outer iterators for a for loop are those for which the initial
1555 * value itself, the increment on each domain iteration and
1556 * the condition on both the initial value and
1557 * the result of incrementing the iterator for each iteration of the domain
1558 * can be evaluated.
1559 * If the loop condition is non-affine, then we only consider validity
1560 * of the initial value.
1562 * If the loop iterator was not declared inside the loop header,
1563 * then the variable corresponding to this loop iterator is assigned
1564 * the result of adding the increment at the end of the loop body.
1565 * The assignment of the initial value is taken care of by
1566 * scop_from_affine_for_init.
1568 * If the body contains any break, then we keep track of it in "skip"
1569 * (if the skip condition is affine) or it is handled in scop_add_break
1570 * (if the skip condition is not affine).
1571 * Note that the affine break condition needs to be considered with
1572 * respect to previous iterations in the virtual domain (if any).
1574 static struct pet_scop *scop_from_affine_for(__isl_keep pet_tree *tree,
1575 __isl_take isl_pw_aff *init_val, __isl_take isl_pw_aff *pa_inc,
1576 __isl_take isl_val *inc, __isl_take pet_context *pc,
1577 struct pet_state *state)
1579 isl_set *domain;
1580 isl_multi_aff *sched;
1581 isl_set *cond = NULL;
1582 isl_set *skip = NULL;
1583 isl_id *id_test = NULL, *id_break_test;
1584 struct pet_scop *scop, *scop_cond = NULL;
1585 int pos;
1586 int is_one;
1587 int is_unsigned;
1588 int is_simple;
1589 int is_virtual;
1590 int is_non_affine;
1591 int has_affine_break;
1592 int has_var_break;
1593 isl_map *rev_wrap = NULL;
1594 isl_map *init_val_map;
1595 isl_pw_aff *pa;
1596 isl_set *valid_init;
1597 isl_set *valid_cond;
1598 isl_set *valid_cond_init;
1599 isl_set *valid_cond_next;
1600 isl_set *valid_inc;
1601 pet_expr *cond_expr;
1602 pet_context *pc_nested;
1604 pos = pet_context_dim(pc) - 1;
1606 domain = pet_context_get_domain(pc);
1607 cond_expr = pet_expr_copy(tree->u.l.cond);
1608 cond_expr = pet_context_evaluate_expr(pc, cond_expr);
1609 pc_nested = pet_context_copy(pc);
1610 pc_nested = pet_context_set_allow_nested(pc_nested, 1);
1611 pa = pet_expr_extract_affine_condition(cond_expr, pc_nested);
1612 pet_context_free(pc_nested);
1613 pet_expr_free(cond_expr);
1615 valid_inc = isl_pw_aff_domain(pa_inc);
1617 is_unsigned = pet_expr_get_type_size(tree->u.l.iv) > 0;
1619 is_non_affine = isl_pw_aff_involves_nan(pa) ||
1620 !is_nested_allowed(pa, tree->u.l.body);
1621 if (is_non_affine)
1622 pa = isl_pw_aff_free(pa);
1624 valid_cond = isl_pw_aff_domain(isl_pw_aff_copy(pa));
1625 cond = isl_pw_aff_non_zero_set(pa);
1626 if (is_non_affine)
1627 cond = isl_set_universe(isl_set_get_space(domain));
1629 valid_cond = isl_set_coalesce(valid_cond);
1630 is_one = isl_val_is_one(inc) || isl_val_is_negone(inc);
1631 is_virtual = is_unsigned &&
1632 (!is_one || can_wrap(cond, tree->u.l.iv, inc));
1634 init_val_map = isl_map_from_pw_aff(isl_pw_aff_copy(init_val));
1635 init_val_map = isl_map_equate(init_val_map, isl_dim_in, pos,
1636 isl_dim_out, 0);
1637 valid_cond_init = enforce_subset(isl_map_domain(init_val_map),
1638 isl_set_copy(valid_cond));
1639 if (is_one && !is_virtual) {
1640 isl_set *cond;
1642 isl_pw_aff_free(init_val);
1643 pa = pet_expr_extract_comparison(
1644 isl_val_is_pos(inc) ? pet_op_ge : pet_op_le,
1645 tree->u.l.iv, tree->u.l.init, pc);
1646 valid_init = isl_pw_aff_domain(isl_pw_aff_copy(pa));
1647 valid_init = isl_set_eliminate(valid_init, isl_dim_set,
1648 isl_set_dim(domain, isl_dim_set) - 1, 1);
1649 cond = isl_pw_aff_non_zero_set(pa);
1650 domain = isl_set_intersect(domain, cond);
1651 } else {
1652 isl_set *strided;
1654 valid_init = isl_pw_aff_domain(isl_pw_aff_copy(init_val));
1655 strided = strided_domain(init_val, isl_val_copy(inc));
1656 domain = isl_set_intersect(domain, strided);
1659 if (is_virtual) {
1660 isl_multi_aff *wrap;
1661 wrap = compute_wrapping(isl_set_get_space(cond), tree->u.l.iv);
1662 pc = pet_context_preimage_domain(pc, wrap);
1663 rev_wrap = isl_map_from_multi_aff(wrap);
1664 rev_wrap = isl_map_reverse(rev_wrap);
1665 cond = isl_set_apply(cond, isl_map_copy(rev_wrap));
1666 valid_cond = isl_set_apply(valid_cond, isl_map_copy(rev_wrap));
1667 valid_inc = isl_set_apply(valid_inc, isl_map_copy(rev_wrap));
1669 is_simple = is_simple_bound(cond, inc);
1670 if (!is_simple) {
1671 cond = isl_set_gist(cond, isl_set_copy(domain));
1672 is_simple = is_simple_bound(cond, inc);
1674 if (!is_simple)
1675 cond = valid_for_each_iteration(cond,
1676 isl_set_copy(domain), isl_val_copy(inc));
1677 cond = isl_set_align_params(cond, isl_set_get_space(domain));
1678 domain = isl_set_intersect(domain, cond);
1679 sched = map_to_last(pc, state->n_loop++, tree->label);
1680 if (isl_val_is_neg(inc))
1681 sched = isl_multi_aff_neg(sched);
1683 valid_cond_next = valid_on_next(valid_cond, isl_set_copy(domain),
1684 isl_val_copy(inc));
1685 valid_inc = enforce_subset(isl_set_copy(domain), valid_inc);
1687 pc = pet_context_intersect_domain(pc, isl_set_copy(domain));
1689 if (is_non_affine) {
1690 isl_space *space;
1691 isl_multi_pw_aff *test_index;
1692 space = isl_set_get_space(domain);
1693 test_index = pet_create_test_index(space, state->n_test++);
1694 scop_cond = scop_from_non_affine_condition(
1695 pet_expr_copy(tree->u.l.cond), state->n_stmt++,
1696 isl_multi_pw_aff_copy(test_index),
1697 pet_tree_get_loc(tree), pc);
1698 id_test = isl_multi_pw_aff_get_tuple_id(test_index,
1699 isl_dim_out);
1700 scop_cond = pet_scop_add_boolean_array(scop_cond,
1701 isl_set_copy(domain), test_index,
1702 state->int_size);
1705 scop = scop_from_tree(tree->u.l.body, pc, state);
1706 has_affine_break = scop &&
1707 pet_scop_has_affine_skip(scop, pet_skip_later);
1708 if (has_affine_break)
1709 skip = pet_scop_get_affine_skip_domain(scop, pet_skip_later);
1710 has_var_break = scop && pet_scop_has_var_skip(scop, pet_skip_later);
1711 if (has_var_break)
1712 id_break_test = pet_scop_get_skip_id(scop, pet_skip_later);
1713 if (is_non_affine) {
1714 scop = pet_scop_reset_context(scop);
1716 if (!tree->u.l.declared)
1717 scop = add_iterator_assignment(scop, tree, pc, state);
1718 scop = pet_scop_reset_skips(scop);
1719 scop = pet_scop_resolve_nested(scop);
1720 if (has_affine_break) {
1721 domain = apply_affine_break(domain, skip, isl_val_sgn(inc),
1722 is_virtual, rev_wrap);
1723 scop = pet_scop_intersect_domain_prefix(scop,
1724 isl_set_copy(domain));
1726 isl_map_free(rev_wrap);
1727 if (has_var_break)
1728 scop = scop_add_break(scop, id_break_test, isl_set_copy(domain),
1729 isl_val_copy(inc));
1730 if (is_non_affine)
1731 scop = scop_add_while(scop_cond, scop, id_test,
1732 isl_set_copy(domain),
1733 isl_val_copy(inc));
1734 else
1735 scop = set_independence(scop, tree, domain, isl_val_sgn(inc),
1736 pc, state);
1737 scop = pet_scop_embed(scop, domain, sched);
1738 if (is_non_affine) {
1739 isl_set_free(valid_inc);
1740 } else {
1741 valid_inc = isl_set_intersect(valid_inc, valid_cond_next);
1742 valid_inc = isl_set_intersect(valid_inc, valid_cond_init);
1743 valid_inc = isl_set_project_out(valid_inc, isl_dim_set, pos, 1);
1744 scop = pet_scop_restrict_context(scop, valid_inc);
1747 isl_val_free(inc);
1749 valid_init = isl_set_project_out(valid_init, isl_dim_set, pos, 1);
1750 scop = pet_scop_restrict_context(scop, valid_init);
1752 pet_context_free(pc);
1753 return scop;
1756 /* Construct a pet_scop for a for tree with static affine initialization
1757 * and constant increment within the context "pc_init".
1758 * In particular, "pc_init" represents the context of the loop,
1759 * whereas the domain of "pc" has already been extended with an (at this point
1760 * unbounded) inner loop iterator corresponding to the current for loop.
1762 * If the loop iterator was not declared inside the loop header,
1763 * then add an assignment of the initial value to the loop iterator
1764 * before the loop. The construction of a pet_scop for the loop itself,
1765 * including updates to the loop iterator, is handled by scop_from_affine_for.
1767 static __isl_give pet_scop *scop_from_affine_for_init(__isl_keep pet_tree *tree,
1768 __isl_take isl_pw_aff *init_val, __isl_take isl_pw_aff *pa_inc,
1769 __isl_take isl_val *inc, __isl_keep pet_context *pc_init,
1770 __isl_take pet_context *pc, struct pet_state *state)
1772 pet_scop *scop_init, *scop;
1774 if (!tree->u.l.declared)
1775 scop_init = scop_from_for_init(tree, pc_init, state);
1777 scop = scop_from_affine_for(tree, init_val, pa_inc, inc, pc, state);
1779 if (!tree->u.l.declared)
1780 scop = pet_scop_add_seq(state->ctx, scop_init, scop);
1782 return scop;
1785 /* Construct a pet_scop for a for statement within the context of "pc".
1787 * We update the context to reflect the writes to the loop variable and
1788 * the writes inside the body.
1790 * Then we check if the initialization of the for loop
1791 * is a static affine value and the increment is a constant.
1792 * If so, we construct the pet_scop using scop_from_affine_for_init.
1793 * Otherwise, we treat the for loop as a while loop
1794 * in scop_from_non_affine_for.
1796 * Note that the initialization and the increment are extracted
1797 * in a context where the current loop iterator has been added
1798 * to the context. If these turn out not be affine, then we
1799 * have reconstruct the body context without an assignment
1800 * to this loop iterator, as this variable will then not be
1801 * treated as a dimension of the iteration domain, but as any
1802 * other variable.
1804 static struct pet_scop *scop_from_for(__isl_keep pet_tree *tree,
1805 __isl_keep pet_context *init_pc, struct pet_state *state)
1807 isl_id *iv;
1808 isl_val *inc;
1809 isl_pw_aff *pa_inc, *init_val;
1810 pet_context *pc, *pc_init_val;
1812 if (!tree)
1813 return NULL;
1815 iv = pet_expr_access_get_id(tree->u.l.iv);
1816 pc = pet_context_copy(init_pc);
1817 pc = pet_context_add_inner_iterator(pc, iv);
1818 pc = pet_context_clear_writes_in_tree(pc, tree->u.l.body);
1820 pc_init_val = pet_context_copy(pc);
1821 pc_init_val = pet_context_clear_value(pc_init_val, isl_id_copy(iv));
1822 init_val = pet_expr_extract_affine(tree->u.l.init, pc_init_val);
1823 pet_context_free(pc_init_val);
1824 pa_inc = pet_expr_extract_affine(tree->u.l.inc, pc);
1825 inc = pet_extract_cst(pa_inc);
1826 if (!pa_inc || !init_val || !inc)
1827 goto error;
1828 if (!isl_pw_aff_involves_nan(pa_inc) &&
1829 !isl_pw_aff_involves_nan(init_val) && !isl_val_is_nan(inc))
1830 return scop_from_affine_for_init(tree, init_val, pa_inc, inc,
1831 init_pc, pc, state);
1833 isl_pw_aff_free(pa_inc);
1834 isl_pw_aff_free(init_val);
1835 isl_val_free(inc);
1836 pet_context_free(pc);
1838 pc = pet_context_copy(init_pc);
1839 pc = pet_context_add_infinite_loop(pc);
1840 pc = pet_context_clear_writes_in_tree(pc, tree->u.l.body);
1841 return scop_from_non_affine_for(tree, init_pc, pc, state);
1842 error:
1843 isl_pw_aff_free(pa_inc);
1844 isl_pw_aff_free(init_val);
1845 isl_val_free(inc);
1846 pet_context_free(pc);
1847 return NULL;
1850 /* Check whether "expr" is an affine constraint within the context "pc".
1852 static int is_affine_condition(__isl_keep pet_expr *expr,
1853 __isl_keep pet_context *pc)
1855 isl_pw_aff *pa;
1856 int is_affine;
1858 pa = pet_expr_extract_affine_condition(expr, pc);
1859 if (!pa)
1860 return -1;
1861 is_affine = !isl_pw_aff_involves_nan(pa);
1862 isl_pw_aff_free(pa);
1864 return is_affine;
1867 /* Check if the given if statement is a conditional assignement
1868 * with a non-affine condition.
1870 * In particular we check if "stmt" is of the form
1872 * if (condition)
1873 * a = f(...);
1874 * else
1875 * a = g(...);
1877 * where the condition is non-affine and a is some array or scalar access.
1879 static int is_conditional_assignment(__isl_keep pet_tree *tree,
1880 __isl_keep pet_context *pc)
1882 int equal;
1883 isl_ctx *ctx;
1884 pet_expr *expr1, *expr2;
1886 ctx = pet_tree_get_ctx(tree);
1887 if (!pet_options_get_detect_conditional_assignment(ctx))
1888 return 0;
1889 if (tree->type != pet_tree_if_else)
1890 return 0;
1891 if (tree->u.i.then_body->type != pet_tree_expr)
1892 return 0;
1893 if (tree->u.i.else_body->type != pet_tree_expr)
1894 return 0;
1895 expr1 = tree->u.i.then_body->u.e.expr;
1896 expr2 = tree->u.i.else_body->u.e.expr;
1897 if (pet_expr_get_type(expr1) != pet_expr_op)
1898 return 0;
1899 if (pet_expr_get_type(expr2) != pet_expr_op)
1900 return 0;
1901 if (pet_expr_op_get_type(expr1) != pet_op_assign)
1902 return 0;
1903 if (pet_expr_op_get_type(expr2) != pet_op_assign)
1904 return 0;
1905 expr1 = pet_expr_get_arg(expr1, 0);
1906 expr2 = pet_expr_get_arg(expr2, 0);
1907 equal = pet_expr_is_equal(expr1, expr2);
1908 pet_expr_free(expr1);
1909 pet_expr_free(expr2);
1910 if (equal < 0 || !equal)
1911 return 0;
1912 if (is_affine_condition(tree->u.i.cond, pc))
1913 return 0;
1915 return 1;
1918 /* Given that "tree" is of the form
1920 * if (condition)
1921 * a = f(...);
1922 * else
1923 * a = g(...);
1925 * where a is some array or scalar access, construct a pet_scop
1926 * corresponding to this conditional assignment within the context "pc".
1927 * "cond_pa" is an affine expression with nested accesses representing
1928 * the condition.
1930 * The constructed pet_scop then corresponds to the expression
1932 * a = condition ? f(...) : g(...)
1934 * All access relations in f(...) are intersected with condition
1935 * while all access relation in g(...) are intersected with the complement.
1937 static struct pet_scop *scop_from_conditional_assignment(
1938 __isl_keep pet_tree *tree, __isl_take isl_pw_aff *cond_pa,
1939 __isl_take pet_context *pc, struct pet_state *state)
1941 int type_size;
1942 isl_set *cond, *comp;
1943 isl_multi_pw_aff *index;
1944 pet_expr *expr1, *expr2;
1945 pet_expr *pe_cond, *pe_then, *pe_else, *pe, *pe_write;
1946 struct pet_scop *scop;
1948 cond = isl_pw_aff_non_zero_set(isl_pw_aff_copy(cond_pa));
1949 comp = isl_pw_aff_zero_set(isl_pw_aff_copy(cond_pa));
1950 index = isl_multi_pw_aff_from_pw_aff(cond_pa);
1952 expr1 = tree->u.i.then_body->u.e.expr;
1953 expr2 = tree->u.i.else_body->u.e.expr;
1955 pe_cond = pet_expr_from_index(index);
1957 pe_then = pet_expr_get_arg(expr1, 1);
1958 pe_then = pet_context_evaluate_expr(pc, pe_then);
1959 pe_then = pet_expr_restrict(pe_then, cond);
1960 pe_else = pet_expr_get_arg(expr2, 1);
1961 pe_else = pet_context_evaluate_expr(pc, pe_else);
1962 pe_else = pet_expr_restrict(pe_else, comp);
1963 pe_write = pet_expr_get_arg(expr1, 0);
1964 pe_write = pet_context_evaluate_expr(pc, pe_write);
1966 pe = pet_expr_new_ternary(pe_cond, pe_then, pe_else);
1967 type_size = pet_expr_get_type_size(pe_write);
1968 pe = pet_expr_new_binary(type_size, pet_op_assign, pe_write, pe);
1970 scop = scop_from_evaluated_expr(pe, state->n_stmt++,
1971 pet_tree_get_loc(tree), pc);
1973 pet_context_free(pc);
1975 return scop;
1978 /* Construct a pet_scop for a non-affine if statement within the context "pc".
1980 * We create a separate statement that writes the result
1981 * of the non-affine condition to a virtual scalar.
1982 * A constraint requiring the value of this virtual scalar to be one
1983 * is added to the iteration domains of the then branch.
1984 * Similarly, a constraint requiring the value of this virtual scalar
1985 * to be zero is added to the iteration domains of the else branch, if any.
1986 * We combine the schedules as a sequence to ensure that the virtual scalar
1987 * is written before it is read.
1989 * If there are any breaks or continues in the then and/or else
1990 * branches, then we may have to compute a new skip condition.
1991 * This is handled using a pet_skip_info object.
1992 * On initialization, the object checks if skip conditions need
1993 * to be computed. If so, it does so in pet_skip_info_if_extract_index and
1994 * adds them in pet_skip_info_add.
1996 static struct pet_scop *scop_from_non_affine_if(__isl_keep pet_tree *tree,
1997 __isl_take pet_context *pc, struct pet_state *state)
1999 int has_else;
2000 isl_space *space;
2001 isl_set *domain;
2002 isl_multi_pw_aff *test_index;
2003 struct pet_skip_info skip;
2004 struct pet_scop *scop, *scop_then, *scop_else = NULL;
2006 has_else = tree->type == pet_tree_if_else;
2008 space = pet_context_get_space(pc);
2009 test_index = pet_create_test_index(space, state->n_test++);
2010 scop = scop_from_non_affine_condition(pet_expr_copy(tree->u.i.cond),
2011 state->n_stmt++, isl_multi_pw_aff_copy(test_index),
2012 pet_tree_get_loc(tree), pc);
2013 domain = pet_context_get_domain(pc);
2014 scop = pet_scop_add_boolean_array(scop, domain,
2015 isl_multi_pw_aff_copy(test_index), state->int_size);
2017 scop_then = scop_from_tree(tree->u.i.then_body, pc, state);
2018 if (has_else)
2019 scop_else = scop_from_tree(tree->u.i.else_body, pc, state);
2021 pet_skip_info_if_init(&skip, state->ctx, scop_then, scop_else,
2022 has_else, 0);
2023 pet_skip_info_if_extract_index(&skip, test_index, pc, state);
2025 scop_then = pet_scop_filter(scop_then,
2026 isl_multi_pw_aff_copy(test_index), 1);
2027 if (has_else) {
2028 scop_else = pet_scop_filter(scop_else, test_index, 0);
2029 scop_then = pet_scop_add_par(state->ctx, scop_then, scop_else);
2030 } else
2031 isl_multi_pw_aff_free(test_index);
2033 scop = pet_scop_add_seq(state->ctx, scop, scop_then);
2035 scop = pet_skip_info_add(&skip, scop);
2037 pet_context_free(pc);
2038 return scop;
2041 /* Construct a pet_scop for an affine if statement within the context "pc".
2043 * The condition is added to the iteration domains of the then branch,
2044 * while the opposite of the condition in added to the iteration domains
2045 * of the else branch, if any.
2047 * If there are any breaks or continues in the then and/or else
2048 * branches, then we may have to compute a new skip condition.
2049 * This is handled using a pet_skip_info_if object.
2050 * On initialization, the object checks if skip conditions need
2051 * to be computed. If so, it does so in pet_skip_info_if_extract_cond and
2052 * adds them in pet_skip_info_add.
2054 static struct pet_scop *scop_from_affine_if(__isl_keep pet_tree *tree,
2055 __isl_take isl_pw_aff *cond, __isl_take pet_context *pc,
2056 struct pet_state *state)
2058 int has_else;
2059 isl_ctx *ctx;
2060 isl_set *set, *complement;
2061 isl_set *valid;
2062 struct pet_skip_info skip;
2063 struct pet_scop *scop, *scop_then, *scop_else = NULL;
2064 pet_context *pc_body;
2066 ctx = pet_tree_get_ctx(tree);
2068 has_else = tree->type == pet_tree_if_else;
2070 valid = isl_pw_aff_domain(isl_pw_aff_copy(cond));
2071 set = isl_pw_aff_non_zero_set(isl_pw_aff_copy(cond));
2073 pc_body = pet_context_copy(pc);
2074 pc_body = pet_context_intersect_domain(pc_body, isl_set_copy(set));
2075 scop_then = scop_from_tree(tree->u.i.then_body, pc_body, state);
2076 pet_context_free(pc_body);
2077 if (has_else) {
2078 pc_body = pet_context_copy(pc);
2079 complement = isl_set_copy(valid);
2080 complement = isl_set_subtract(valid, isl_set_copy(set));
2081 pc_body = pet_context_intersect_domain(pc_body,
2082 isl_set_copy(complement));
2083 scop_else = scop_from_tree(tree->u.i.else_body, pc_body, state);
2084 pet_context_free(pc_body);
2087 pet_skip_info_if_init(&skip, ctx, scop_then, scop_else, has_else, 1);
2088 pet_skip_info_if_extract_cond(&skip, cond, pc, state);
2089 isl_pw_aff_free(cond);
2091 scop = pet_scop_restrict(scop_then, set);
2093 if (has_else) {
2094 scop_else = pet_scop_restrict(scop_else, complement);
2095 scop = pet_scop_add_par(ctx, scop, scop_else);
2097 scop = pet_scop_resolve_nested(scop);
2098 scop = pet_scop_restrict_context(scop, valid);
2100 scop = pet_skip_info_add(&skip, scop);
2102 pet_context_free(pc);
2103 return scop;
2106 /* Construct a pet_scop for an if statement within the context "pc".
2108 * If the condition fits the pattern of a conditional assignment,
2109 * then it is handled by scop_from_conditional_assignment.
2110 * Note that the condition is only considered for a conditional assignment
2111 * if it is not static-affine. However, it should still convert
2112 * to an affine expression when nesting is allowed.
2114 * Otherwise, we check if the condition is affine.
2115 * If so, we construct the scop in scop_from_affine_if.
2116 * Otherwise, we construct the scop in scop_from_non_affine_if.
2118 * We allow the condition to be dynamic, i.e., to refer to
2119 * scalars or array elements that may be written to outside
2120 * of the given if statement. These nested accesses are then represented
2121 * as output dimensions in the wrapping iteration domain.
2122 * If it is also written _inside_ the then or else branch, then
2123 * we treat the condition as non-affine.
2124 * As explained in extract_non_affine_if, this will introduce
2125 * an extra statement.
2126 * For aesthetic reasons, we want this statement to have a statement
2127 * number that is lower than those of the then and else branches.
2128 * In order to evaluate if we will need such a statement, however, we
2129 * first construct scops for the then and else branches.
2130 * We therefore reserve a statement number if we might have to
2131 * introduce such an extra statement.
2133 static struct pet_scop *scop_from_if(__isl_keep pet_tree *tree,
2134 __isl_keep pet_context *pc, struct pet_state *state)
2136 int has_else;
2137 isl_pw_aff *cond;
2138 pet_expr *cond_expr;
2139 pet_context *pc_nested;
2141 if (!tree)
2142 return NULL;
2144 has_else = tree->type == pet_tree_if_else;
2146 pc = pet_context_copy(pc);
2147 pc = pet_context_clear_writes_in_tree(pc, tree->u.i.then_body);
2148 if (has_else)
2149 pc = pet_context_clear_writes_in_tree(pc, tree->u.i.else_body);
2151 cond_expr = pet_expr_copy(tree->u.i.cond);
2152 cond_expr = pet_context_evaluate_expr(pc, cond_expr);
2153 pc_nested = pet_context_copy(pc);
2154 pc_nested = pet_context_set_allow_nested(pc_nested, 1);
2155 cond = pet_expr_extract_affine_condition(cond_expr, pc_nested);
2156 pet_context_free(pc_nested);
2157 pet_expr_free(cond_expr);
2159 if (!cond) {
2160 pet_context_free(pc);
2161 return NULL;
2164 if (isl_pw_aff_involves_nan(cond)) {
2165 isl_pw_aff_free(cond);
2166 return scop_from_non_affine_if(tree, pc, state);
2169 if (is_conditional_assignment(tree, pc))
2170 return scop_from_conditional_assignment(tree, cond, pc, state);
2172 if ((!is_nested_allowed(cond, tree->u.i.then_body) ||
2173 (has_else && !is_nested_allowed(cond, tree->u.i.else_body)))) {
2174 isl_pw_aff_free(cond);
2175 return scop_from_non_affine_if(tree, pc, state);
2178 return scop_from_affine_if(tree, cond, pc, state);
2181 /* Return a one-dimensional multi piecewise affine expression that is equal
2182 * to the constant 1 and is defined over the given domain.
2184 static __isl_give isl_multi_pw_aff *one_mpa(__isl_take isl_space *space)
2186 isl_local_space *ls;
2187 isl_aff *aff;
2189 ls = isl_local_space_from_space(space);
2190 aff = isl_aff_zero_on_domain(ls);
2191 aff = isl_aff_set_constant_si(aff, 1);
2193 return isl_multi_pw_aff_from_pw_aff(isl_pw_aff_from_aff(aff));
2196 /* Construct a pet_scop for a continue statement with the given domain space.
2198 * We simply create an empty scop with a universal pet_skip_now
2199 * skip condition. This skip condition will then be taken into
2200 * account by the enclosing loop construct, possibly after
2201 * being incorporated into outer skip conditions.
2203 static struct pet_scop *scop_from_continue(__isl_keep pet_tree *tree,
2204 __isl_take isl_space *space)
2206 struct pet_scop *scop;
2208 scop = pet_scop_empty(isl_space_copy(space));
2210 scop = pet_scop_set_skip(scop, pet_skip_now, one_mpa(space));
2212 return scop;
2215 /* Construct a pet_scop for a break statement with the given domain space.
2217 * We simply create an empty scop with both a universal pet_skip_now
2218 * skip condition and a universal pet_skip_later skip condition.
2219 * These skip conditions will then be taken into
2220 * account by the enclosing loop construct, possibly after
2221 * being incorporated into outer skip conditions.
2223 static struct pet_scop *scop_from_break(__isl_keep pet_tree *tree,
2224 __isl_take isl_space *space)
2226 struct pet_scop *scop;
2227 isl_multi_pw_aff *skip;
2229 scop = pet_scop_empty(isl_space_copy(space));
2231 skip = one_mpa(space);
2232 scop = pet_scop_set_skip(scop, pet_skip_now,
2233 isl_multi_pw_aff_copy(skip));
2234 scop = pet_scop_set_skip(scop, pet_skip_later, skip);
2236 return scop;
2239 /* Extract a clone of the kill statement "stmt".
2240 * The domain of the clone is given by "domain".
2242 static struct pet_scop *extract_kill(__isl_keep isl_set *domain,
2243 struct pet_stmt *stmt, struct pet_state *state)
2245 pet_expr *kill;
2246 isl_space *space;
2247 isl_multi_pw_aff *mpa;
2248 pet_tree *tree;
2250 if (!domain || !stmt)
2251 return NULL;
2253 kill = pet_tree_expr_get_expr(stmt->body);
2254 space = pet_stmt_get_space(stmt);
2255 space = isl_space_map_from_set(space);
2256 mpa = isl_multi_pw_aff_identity(space);
2257 mpa = isl_multi_pw_aff_reset_tuple_id(mpa, isl_dim_in);
2258 kill = pet_expr_update_domain(kill, mpa);
2259 tree = pet_tree_new_expr(kill);
2260 tree = pet_tree_set_loc(tree, pet_loc_copy(stmt->loc));
2261 stmt = pet_stmt_from_pet_tree(isl_set_copy(domain),
2262 state->n_stmt++, tree);
2263 return pet_scop_from_pet_stmt(isl_set_get_space(domain), stmt);
2266 /* Extract a clone of the kill statements in "scop".
2267 * The domain of each clone is given by "domain".
2268 * "scop" is expected to have been created from a DeclStmt
2269 * and should have (one of) the kill(s) as its first statement.
2270 * If "scop" was created from a declaration group, then there
2271 * may be multiple kill statements inside.
2273 static struct pet_scop *extract_kills(__isl_keep isl_set *domain,
2274 struct pet_scop *scop, struct pet_state *state)
2276 isl_ctx *ctx;
2277 struct pet_stmt *stmt;
2278 struct pet_scop *kill;
2279 int i;
2281 if (!domain || !scop)
2282 return NULL;
2283 ctx = isl_set_get_ctx(domain);
2284 if (scop->n_stmt < 1)
2285 isl_die(ctx, isl_error_internal,
2286 "expecting at least one statement", return NULL);
2287 stmt = scop->stmts[0];
2288 if (!pet_stmt_is_kill(stmt))
2289 isl_die(ctx, isl_error_internal,
2290 "expecting kill statement", return NULL);
2292 kill = extract_kill(domain, stmt, state);
2294 for (i = 1; i < scop->n_stmt; ++i) {
2295 struct pet_scop *kill_i;
2297 stmt = scop->stmts[i];
2298 if (!pet_stmt_is_kill(stmt))
2299 continue;
2301 kill_i = extract_kill(domain, stmt, state);
2302 kill = pet_scop_add_par(ctx, kill, kill_i);
2305 return kill;
2308 /* Has "tree" been created from a DeclStmt?
2309 * That is, is it either a declaration or a group of declarations?
2311 static int tree_is_decl(__isl_keep pet_tree *tree)
2313 int is_decl;
2314 int i;
2316 if (!tree)
2317 return -1;
2318 is_decl = pet_tree_is_decl(tree);
2319 if (is_decl < 0 || is_decl)
2320 return is_decl;
2322 if (tree->type != pet_tree_block)
2323 return 0;
2324 if (pet_tree_block_get_block(tree))
2325 return 0;
2326 if (tree->u.b.n == 0)
2327 return 0;
2329 for (i = 0; i < tree->u.b.n; ++i) {
2330 is_decl = tree_is_decl(tree->u.b.child[i]);
2331 if (is_decl < 0 || !is_decl)
2332 return is_decl;
2335 return 1;
2338 /* Does "tree" represent an assignment to a variable?
2340 * The assignment may be one of
2341 * - a declaration with initialization
2342 * - an expression with a top-level assignment operator
2344 static int is_assignment(__isl_keep pet_tree *tree)
2346 if (!tree)
2347 return 0;
2348 if (tree->type == pet_tree_decl_init)
2349 return 1;
2350 return pet_tree_is_assign(tree);
2353 /* Update "pc" by taking into account the assignment performed by "tree",
2354 * where "tree" satisfies is_assignment.
2356 * In particular, if the lhs of the assignment is a scalar variable and
2357 * if the rhs is an affine expression, then keep track of this value in "pc"
2358 * so that we can plug it in when we later come across the same variable.
2360 * Any previously assigned value to the variable has already been removed
2361 * by scop_handle_writes.
2363 static __isl_give pet_context *handle_assignment(__isl_take pet_context *pc,
2364 __isl_keep pet_tree *tree)
2366 pet_expr *var, *val;
2367 isl_id *id;
2368 isl_pw_aff *pa;
2370 if (pet_tree_get_type(tree) == pet_tree_decl_init) {
2371 var = pet_tree_decl_get_var(tree);
2372 val = pet_tree_decl_get_init(tree);
2373 } else {
2374 pet_expr *expr;
2375 expr = pet_tree_expr_get_expr(tree);
2376 var = pet_expr_get_arg(expr, 0);
2377 val = pet_expr_get_arg(expr, 1);
2378 pet_expr_free(expr);
2381 if (!pet_expr_is_scalar_access(var)) {
2382 pet_expr_free(var);
2383 pet_expr_free(val);
2384 return pc;
2387 pa = pet_expr_extract_affine(val, pc);
2388 if (!pa)
2389 pc = pet_context_free(pc);
2391 if (!isl_pw_aff_involves_nan(pa)) {
2392 id = pet_expr_access_get_id(var);
2393 pc = pet_context_set_value(pc, id, pa);
2394 } else {
2395 isl_pw_aff_free(pa);
2397 pet_expr_free(var);
2398 pet_expr_free(val);
2400 return pc;
2403 /* Mark all arrays in "scop" as being exposed.
2405 static struct pet_scop *mark_exposed(struct pet_scop *scop)
2407 int i;
2409 if (!scop)
2410 return NULL;
2411 for (i = 0; i < scop->n_array; ++i)
2412 scop->arrays[i]->exposed = 1;
2413 return scop;
2416 /* Try and construct a pet_scop corresponding to (part of)
2417 * a sequence of statements within the context "pc".
2419 * After extracting a statement, we update "pc"
2420 * based on the top-level assignments in the statement
2421 * so that we can exploit them in subsequent statements in the same block.
2423 * If there are any breaks or continues in the individual statements,
2424 * then we may have to compute a new skip condition.
2425 * This is handled using a pet_skip_info object.
2426 * On initialization, the object checks if skip conditions need
2427 * to be computed. If so, it does so in pet_skip_info_seq_extract and
2428 * adds them in pet_skip_info_add.
2430 * If "block" is set, then we need to insert kill statements at
2431 * the end of the block for any array that has been declared by
2432 * one of the statements in the sequence. Each of these declarations
2433 * results in the construction of a kill statement at the place
2434 * of the declaration, so we simply collect duplicates of
2435 * those kill statements and append these duplicates to the constructed scop.
2437 * If "block" is not set, then any array declared by one of the statements
2438 * in the sequence is marked as being exposed.
2440 * If autodetect is set, then we allow the extraction of only a subrange
2441 * of the sequence of statements. However, if there is at least one statement
2442 * for which we could not construct a scop and the final range contains
2443 * either no statements or at least one kill, then we discard the entire
2444 * range.
2446 static struct pet_scop *scop_from_block(__isl_keep pet_tree *tree,
2447 __isl_keep pet_context *pc, struct pet_state *state)
2449 int i;
2450 isl_ctx *ctx;
2451 isl_space *space;
2452 isl_set *domain;
2453 struct pet_scop *scop, *kills;
2455 ctx = pet_tree_get_ctx(tree);
2457 space = pet_context_get_space(pc);
2458 domain = pet_context_get_domain(pc);
2459 pc = pet_context_copy(pc);
2460 scop = pet_scop_empty(isl_space_copy(space));
2461 kills = pet_scop_empty(space);
2462 for (i = 0; i < tree->u.b.n; ++i) {
2463 struct pet_scop *scop_i;
2465 if (pet_scop_has_affine_skip(scop, pet_skip_now))
2466 pc = apply_affine_continue(pc, scop);
2467 scop_i = scop_from_tree(tree->u.b.child[i], pc, state);
2468 pc = scop_handle_writes(scop_i, pc);
2469 if (is_assignment(tree->u.b.child[i]))
2470 pc = handle_assignment(pc, tree->u.b.child[i]);
2471 struct pet_skip_info skip;
2472 pet_skip_info_seq_init(&skip, ctx, scop, scop_i);
2473 pet_skip_info_seq_extract(&skip, pc, state);
2474 if (scop_i && tree_is_decl(tree->u.b.child[i])) {
2475 if (tree->u.b.block) {
2476 struct pet_scop *kill;
2477 kill = extract_kills(domain, scop_i, state);
2478 kills = pet_scop_add_par(ctx, kills, kill);
2479 } else
2480 scop_i = mark_exposed(scop_i);
2482 scop = pet_scop_add_seq(ctx, scop, scop_i);
2484 scop = pet_skip_info_add(&skip, scop);
2486 if (!scop)
2487 break;
2489 isl_set_free(domain);
2491 scop = pet_scop_add_seq(ctx, scop, kills);
2493 pet_context_free(pc);
2495 return scop;
2498 /* Internal data structure for extract_declared_arrays.
2500 * "pc" and "state" are used to create pet_array objects and kill statements.
2501 * "any" is initialized to 0 by the caller and set to 1 as soon as we have
2502 * found any declared array.
2503 * "scop" has been initialized by the caller and is used to attach
2504 * the created pet_array objects.
2505 * "kill_before" and "kill_after" are created and updated by
2506 * extract_declared_arrays to collect the kills of the arrays.
2508 struct pet_tree_extract_declared_arrays_data {
2509 pet_context *pc;
2510 struct pet_state *state;
2512 isl_ctx *ctx;
2514 int any;
2515 struct pet_scop *scop;
2516 struct pet_scop *kill_before;
2517 struct pet_scop *kill_after;
2520 /* Check if the node "node" declares any array or scalar.
2521 * If so, create the corresponding pet_array and attach it to data->scop.
2522 * Additionally, create two kill statements for the array and add them
2523 * to data->kill_before and data->kill_after.
2525 static int extract_declared_arrays(__isl_keep pet_tree *node, void *user)
2527 enum pet_tree_type type;
2528 struct pet_tree_extract_declared_arrays_data *data = user;
2529 struct pet_array *array;
2530 struct pet_scop *scop_kill;
2531 pet_expr *var;
2533 type = pet_tree_get_type(node);
2534 if (type == pet_tree_decl || type == pet_tree_decl_init)
2535 var = node->u.d.var;
2536 else if (type == pet_tree_for && node->u.l.declared)
2537 var = node->u.l.iv;
2538 else
2539 return 0;
2541 array = extract_array(var, data->pc, data->state);
2542 if (array)
2543 array->declared = 1;
2544 data->scop = pet_scop_add_array(data->scop, array);
2546 scop_kill = kill(pet_tree_get_loc(node), array, data->pc, data->state);
2547 if (!data->any)
2548 data->kill_before = scop_kill;
2549 else
2550 data->kill_before = pet_scop_add_par(data->ctx,
2551 data->kill_before, scop_kill);
2553 scop_kill = kill(pet_tree_get_loc(node), array, data->pc, data->state);
2554 if (!data->any)
2555 data->kill_after = scop_kill;
2556 else
2557 data->kill_after = pet_scop_add_par(data->ctx,
2558 data->kill_after, scop_kill);
2560 data->any = 1;
2562 return 0;
2565 /* Convert a pet_tree that consists of more than a single leaf
2566 * to a pet_scop with a single statement encapsulating the entire pet_tree.
2567 * Do so within the context of "pc", taking into account the writes inside
2568 * "tree". That is, first clear any previously assigned values to variables
2569 * that are written by "tree".
2571 * After constructing the core scop, we also look for any arrays (or scalars)
2572 * that are declared inside "tree". Each of those arrays is marked as
2573 * having been declared and kill statements for these arrays
2574 * are introduced before and after the core scop.
2575 * Note that the input tree is not a leaf so that the declaration
2576 * cannot occur at the outer level.
2578 static struct pet_scop *scop_from_tree_macro(__isl_take pet_tree *tree,
2579 __isl_keep pet_context *pc, struct pet_state *state)
2581 struct pet_tree_extract_declared_arrays_data data = { pc, state };
2583 data.pc = pet_context_copy(data.pc);
2584 data.pc = pet_context_clear_writes_in_tree(data.pc, tree);
2585 data.scop = scop_from_unevaluated_tree(pet_tree_copy(tree),
2586 state->n_stmt++, data.pc);
2588 data.any = 0;
2589 data.ctx = pet_context_get_ctx(data.pc);
2590 if (pet_tree_foreach_sub_tree(tree, &extract_declared_arrays,
2591 &data) < 0)
2592 data.scop = pet_scop_free(data.scop);
2593 pet_tree_free(tree);
2594 pet_context_free(data.pc);
2596 if (!data.any)
2597 return data.scop;
2599 data.scop = pet_scop_add_seq(data.ctx, data.kill_before, data.scop);
2600 data.scop = pet_scop_add_seq(data.ctx, data.scop, data.kill_after);
2602 return data.scop;
2605 /* Construct a pet_scop that corresponds to the pet_tree "tree"
2606 * within the context "pc" by calling the appropriate function
2607 * based on the type of "tree".
2609 * If the initially constructed pet_scop turns out to involve
2610 * dynamic control and if the user has requested an encapsulation
2611 * of all dynamic control, then this pet_scop is discarded and
2612 * a new pet_scop is created with a single statement representing
2613 * the entire "tree".
2614 * However, if the scop contains any active continue or break,
2615 * then we need to include the loop containing the continue or break
2616 * in the encapsulation. We therefore postpone the encapsulation
2617 * until we have constructed a pet_scop for this enclosing loop.
2619 static struct pet_scop *scop_from_tree(__isl_keep pet_tree *tree,
2620 __isl_keep pet_context *pc, struct pet_state *state)
2622 isl_ctx *ctx;
2623 struct pet_scop *scop = NULL;
2625 if (!tree)
2626 return NULL;
2628 ctx = pet_tree_get_ctx(tree);
2629 switch (tree->type) {
2630 case pet_tree_error:
2631 return NULL;
2632 case pet_tree_block:
2633 return scop_from_block(tree, pc, state);
2634 case pet_tree_break:
2635 return scop_from_break(tree, pet_context_get_space(pc));
2636 case pet_tree_continue:
2637 return scop_from_continue(tree, pet_context_get_space(pc));
2638 case pet_tree_decl:
2639 case pet_tree_decl_init:
2640 return scop_from_decl(tree, pc, state);
2641 case pet_tree_expr:
2642 return scop_from_tree_expr(tree, pc, state);
2643 case pet_tree_if:
2644 case pet_tree_if_else:
2645 scop = scop_from_if(tree, pc, state);
2646 break;
2647 case pet_tree_for:
2648 scop = scop_from_for(tree, pc, state);
2649 break;
2650 case pet_tree_while:
2651 scop = scop_from_while(tree, pc, state);
2652 break;
2653 case pet_tree_infinite_loop:
2654 scop = scop_from_infinite_for(tree, pc, state);
2655 break;
2658 if (!scop)
2659 return NULL;
2661 if (!pet_options_get_encapsulate_dynamic_control(ctx) ||
2662 !pet_scop_has_data_dependent_conditions(scop) ||
2663 pet_scop_has_var_skip(scop, pet_skip_now))
2664 return scop;
2666 pet_scop_free(scop);
2667 return scop_from_tree_macro(pet_tree_copy(tree), pc, state);
2670 /* If "tree" has a label that is of the form S_<nr>, then make
2671 * sure that state->n_stmt is greater than nr to ensure that
2672 * we will not generate S_<nr> ourselves.
2674 static int set_first_stmt(__isl_keep pet_tree *tree, void *user)
2676 struct pet_state *state = user;
2677 const char *name;
2678 int nr;
2680 if (!tree)
2681 return -1;
2682 if (!tree->label)
2683 return 0;
2684 name = isl_id_get_name(tree->label);
2685 if (strncmp(name, "S_", 2) != 0)
2686 return 0;
2687 nr = atoi(name + 2);
2688 if (nr >= state->n_stmt)
2689 state->n_stmt = nr + 1;
2691 return 0;
2694 /* Construct a pet_scop that corresponds to the pet_tree "tree".
2695 * "int_size" is the number of bytes need to represent an integer.
2696 * "extract_array" is a callback that we can use to create a pet_array
2697 * that corresponds to the variable accessed by an expression.
2699 * Initialize the global state, construct a context and then
2700 * construct the pet_scop by recursively visiting the tree.
2702 * state.n_stmt is initialized to point beyond any explicit S_<nr> label.
2704 struct pet_scop *pet_scop_from_pet_tree(__isl_take pet_tree *tree, int int_size,
2705 struct pet_array *(*extract_array)(__isl_keep pet_expr *access,
2706 __isl_keep pet_context *pc, void *user), void *user,
2707 __isl_keep pet_context *pc)
2709 struct pet_scop *scop;
2710 struct pet_state state = { 0 };
2712 if (!tree)
2713 return NULL;
2715 state.ctx = pet_tree_get_ctx(tree);
2716 state.int_size = int_size;
2717 state.extract_array = extract_array;
2718 state.user = user;
2719 if (pet_tree_foreach_sub_tree(tree, &set_first_stmt, &state) < 0)
2720 tree = pet_tree_free(tree);
2722 scop = scop_from_tree(tree, pc, &state);
2723 scop = pet_scop_set_loc(scop, pet_tree_get_loc(tree));
2725 pet_tree_free(tree);
2727 if (scop)
2728 scop->context = isl_set_params(scop->context);
2730 return scop;