?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
isl_mat_dump: also indent NULL mat
[isl.git] / isl_map_simplify.c
blob93c799bd2dff169b34c25079629ae23c37f2a9d0
1 #include "isl_equalities.h"
2 #include "isl_map.h"
3 #include "isl_map_private.h"
4
5 static void swap_equality(struct isl_basic_map *bmap, int a, int b)
6 {
7 isl_int *t = bmap->eq[a];
8 bmap->eq[a] = bmap->eq[b];
9 bmap->eq[b] = t;
10 }
11
12 static void swap_inequality(struct isl_basic_map *bmap, int a, int b)
13 {
14 if (a != b) {
15 isl_int *t = bmap->ineq[a];
16 bmap->ineq[a] = bmap->ineq[b];
17 bmap->ineq[b] = t;
18 }
19 }
20
21 static void set_swap_inequality(struct isl_basic_set *bset, int a, int b)
22 {
23 swap_inequality((struct isl_basic_map *)bset, a, b);
24 }
25
26 static void constraint_drop_vars(isl_int *c, unsigned n, unsigned rem)
27 {
28 isl_seq_cpy(c, c + n, rem);
29 isl_seq_clr(c + rem, n);
30 }
31
32 /* Drop n dimensions starting at first.
33 *
34 * In principle, this frees up some extra variables as the number
35 * of columns remains constant, but we would have to extend
36 * the div array too as the number of rows in this array is assumed
37 * to be equal to extra.
38 */
39 struct isl_basic_set *isl_basic_set_drop_dims(
40 struct isl_basic_set *bset, unsigned first, unsigned n)
41 {
42 int i;
43
44 if (!bset)
45 goto error;
46
47 isl_assert(bset->ctx, first + n <= bset->dim->n_out, goto error);
48
49 if (n == 0)
50 return bset;
51
52 bset = isl_basic_set_cow(bset);
53 if (!bset)
54 return NULL;
55
56 for (i = 0; i < bset->n_eq; ++i)
57 constraint_drop_vars(bset->eq[i]+1+bset->dim->nparam+first, n,
58 (bset->dim->n_out-first-n)+bset->extra);
59
60 for (i = 0; i < bset->n_ineq; ++i)
61 constraint_drop_vars(bset->ineq[i]+1+bset->dim->nparam+first, n,
62 (bset->dim->n_out-first-n)+bset->extra);
63
64 for (i = 0; i < bset->n_div; ++i)
65 constraint_drop_vars(bset->div[i]+1+1+bset->dim->nparam+first, n,
66 (bset->dim->n_out-first-n)+bset->extra);
67
68 bset->dim = isl_dim_drop_outputs(bset->dim, first, n);
69 if (!bset->dim)
70 goto error;
71
72 F_CLR(bset, ISL_BASIC_SET_NORMALIZED);
73 bset = isl_basic_set_simplify(bset);
74 return isl_basic_set_finalize(bset);
75 error:
76 isl_basic_set_free(bset);
77 return NULL;
78 }
79
80 struct isl_set *isl_set_drop_dims(
81 struct isl_set *set, unsigned first, unsigned n)
82 {
83 int i;
84
85 if (!set)
86 goto error;
87
88 isl_assert(set->ctx, first + n <= set->dim->n_out, goto error);
89
90 if (n == 0)
91 return set;
92 set = isl_set_cow(set);
93 if (!set)
94 goto error;
95 set->dim = isl_dim_drop_outputs(set->dim, first, n);
96 if (!set->dim)
97 goto error;
98
99 for (i = 0; i < set->n; ++i) {
100 set->p[i] = isl_basic_set_drop_dims(set->p[i], first, n);
101 if (!set->p[i])
102 goto error;
103 }
104
105 F_CLR(set, ISL_SET_NORMALIZED);
106 return set;
107 error:
108 isl_set_free(set);
109 return NULL;
110 }
111
112 /* Drop n input dimensions starting at first.
113 *
114 * In principle, this frees up some extra variables as the number
115 * of columns remains constant, but we would have to extend
116 * the div array too as the number of rows in this array is assumed
117 * to be equal to extra.
118 */
119 struct isl_basic_map *isl_basic_map_drop(struct isl_basic_map *bmap,
120 enum isl_dim_type type, unsigned first, unsigned n)
121 {
122 int i;
123 unsigned dim;
124 unsigned offset;
125 unsigned left;
126
127 if (!bmap)
128 goto error;
129
130 dim = isl_basic_map_dim(bmap, type);
131 isl_assert(bmap->ctx, first + n <= dim, goto error);
132
133 if (n == 0)
134 return bmap;
135
136 bmap = isl_basic_map_cow(bmap);
137 if (!bmap)
138 return NULL;
139
140 offset = isl_basic_map_offset(bmap, type) + first;
141 left = isl_basic_map_total_dim(bmap) - (offset - 1) - n;
142 for (i = 0; i < bmap->n_eq; ++i)
143 constraint_drop_vars(bmap->eq[i]+offset, n, left);
144
145 for (i = 0; i < bmap->n_ineq; ++i)
146 constraint_drop_vars(bmap->ineq[i]+offset, n, left);
147
148 for (i = 0; i < bmap->n_div; ++i)
149 constraint_drop_vars(bmap->div[i]+1+offset, n, left);
150
151 bmap->dim = isl_dim_drop(bmap->dim, type, first, n);
152 if (!bmap->dim)
153 goto error;
154
155 F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);
156 bmap = isl_basic_map_simplify(bmap);
157 return isl_basic_map_finalize(bmap);
158 error:
159 isl_basic_map_free(bmap);
160 return NULL;
161 }
162
163 struct isl_basic_map *isl_basic_map_drop_inputs(
164 struct isl_basic_map *bmap, unsigned first, unsigned n)
165 {
166 return isl_basic_map_drop(bmap, isl_dim_in, first, n);
167 }
168
169 struct isl_map *isl_map_drop(struct isl_map *map,
170 enum isl_dim_type type, unsigned first, unsigned n)
171 {
172 int i;
173
174 if (!map)
175 goto error;
176
177 isl_assert(map->ctx, first + n <= isl_map_dim(map, type), goto error);
178
179 if (n == 0)
180 return map;
181 map = isl_map_cow(map);
182 if (!map)
183 goto error;
184 map->dim = isl_dim_drop(map->dim, type, first, n);
185 if (!map->dim)
186 goto error;
187
188 for (i = 0; i < map->n; ++i) {
189 map->p[i] = isl_basic_map_drop(map->p[i], type, first, n);
190 if (!map->p[i])
191 goto error;
192 }
193 F_CLR(map, ISL_MAP_NORMALIZED);
194
195 return map;
196 error:
197 isl_map_free(map);
198 return NULL;
199 }
200
201 struct isl_map *isl_map_drop_inputs(
202 struct isl_map *map, unsigned first, unsigned n)
203 {
204 return isl_map_drop(map, isl_dim_in, first, n);
205 }
206
207 /*
208 * We don't cow, as the div is assumed to be redundant.
209 */
210 static struct isl_basic_map *isl_basic_map_drop_div(
211 struct isl_basic_map *bmap, unsigned div)
212 {
213 int i;
214 unsigned pos;
215
216 if (!bmap)
217 goto error;
218
219 pos = 1 + isl_dim_total(bmap->dim) + div;
220
221 isl_assert(bmap->ctx, div < bmap->n_div, goto error);
222
223 for (i = 0; i < bmap->n_eq; ++i)
224 constraint_drop_vars(bmap->eq[i]+pos, 1, bmap->extra-div-1);
225
226 for (i = 0; i < bmap->n_ineq; ++i) {
227 if (!isl_int_is_zero(bmap->ineq[i][pos])) {
228 isl_basic_map_drop_inequality(bmap, i);
229 --i;
230 continue;
231 }
232 constraint_drop_vars(bmap->ineq[i]+pos, 1, bmap->extra-div-1);
233 }
234
235 for (i = 0; i < bmap->n_div; ++i)
236 constraint_drop_vars(bmap->div[i]+1+pos, 1, bmap->extra-div-1);
237
238 if (div != bmap->n_div - 1) {
239 int j;
240 isl_int *t = bmap->div[div];
241
242 for (j = div; j < bmap->n_div - 1; ++j)
243 bmap->div[j] = bmap->div[j+1];
244
245 bmap->div[bmap->n_div - 1] = t;
246 }
247 F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);
248 isl_basic_map_free_div(bmap, 1);
249
250 return bmap;
251 error:
252 isl_basic_map_free(bmap);
253 return NULL;
254 }
255
256 static struct isl_basic_map *normalize_constraints(struct isl_basic_map *bmap)
257 {
258 int i;
259 isl_int gcd;
260 unsigned total = isl_basic_map_total_dim(bmap);
261
262 isl_int_init(gcd);
263 for (i = bmap->n_eq - 1; i >= 0; --i) {
264 isl_seq_gcd(bmap->eq[i]+1, total, &gcd);
265 if (isl_int_is_zero(gcd)) {
266 if (!isl_int_is_zero(bmap->eq[i][0])) {
267 bmap = isl_basic_map_set_to_empty(bmap);
268 break;
269 }
270 isl_basic_map_drop_equality(bmap, i);
271 continue;
272 }
273 if (F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL))
274 isl_int_gcd(gcd, gcd, bmap->eq[i][0]);
275 if (isl_int_is_one(gcd))
276 continue;
277 if (!isl_int_is_divisible_by(bmap->eq[i][0], gcd)) {
278 bmap = isl_basic_map_set_to_empty(bmap);
279 break;
280 }
281 isl_seq_scale_down(bmap->eq[i], bmap->eq[i], gcd, 1+total);
282 }
283
284 for (i = bmap->n_ineq - 1; i >= 0; --i) {
285 isl_seq_gcd(bmap->ineq[i]+1, total, &gcd);
286 if (isl_int_is_zero(gcd)) {
287 if (isl_int_is_neg(bmap->ineq[i][0])) {
288 bmap = isl_basic_map_set_to_empty(bmap);
289 break;
290 }
291 isl_basic_map_drop_inequality(bmap, i);
292 continue;
293 }
294 if (F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL))
295 isl_int_gcd(gcd, gcd, bmap->ineq[i][0]);
296 if (isl_int_is_one(gcd))
297 continue;
298 isl_int_fdiv_q(bmap->ineq[i][0], bmap->ineq[i][0], gcd);
299 isl_seq_scale_down(bmap->ineq[i]+1, bmap->ineq[i]+1, gcd, total);
300 }
301 isl_int_clear(gcd);
302
303 return bmap;
304 }
305
306 static void eliminate_div(struct isl_basic_map *bmap, isl_int *eq, unsigned div)
307 {
308 int i;
309 unsigned pos = 1 + isl_dim_total(bmap->dim) + div;
310 unsigned len;
311 len = 1 + isl_basic_map_total_dim(bmap);
312
313 for (i = 0; i < bmap->n_eq; ++i)
314 if (bmap->eq[i] != eq)
315 isl_seq_elim(bmap->eq[i], eq, pos, len, NULL);
316
317 for (i = 0; i < bmap->n_ineq; ++i)
318 isl_seq_elim(bmap->ineq[i], eq, pos, len, NULL);
319
320 /* We need to be careful about circular definitions,
321 * so for now we just remove the definitions of other divs that
322 * depend on this div and (possibly) recompute them later.
323 */
324 for (i = 0; i < bmap->n_div; ++i)
325 if (!isl_int_is_zero(bmap->div[i][0]) &&
326 !isl_int_is_zero(bmap->div[i][1 + pos]))
327 isl_seq_clr(bmap->div[i], 1 + len);
328
329 isl_basic_map_drop_div(bmap, div);
330 }
331
332 /* Elimininate divs based on equalities
333 */
334 static struct isl_basic_map *eliminate_divs_eq(
335 struct isl_basic_map *bmap, int *progress)
336 {
337 int d;
338 int i;
339 int modified = 0;
340 unsigned off;
341
342 if (!bmap)
343 return NULL;
344
345 off = 1 + isl_dim_total(bmap->dim);
346
347 for (d = bmap->n_div - 1; d >= 0 ; --d) {
348 for (i = 0; i < bmap->n_eq; ++i) {
349 if (!isl_int_is_one(bmap->eq[i][off + d]) &&
350 !isl_int_is_negone(bmap->eq[i][off + d]))
351 continue;
352 modified = 1;
353 *progress = 1;
354 eliminate_div(bmap, bmap->eq[i], d);
355 isl_basic_map_drop_equality(bmap, i);
356 break;
357 }
358 }
359 if (modified)
360 return eliminate_divs_eq(bmap, progress);
361 return bmap;
362 }
363
364 /* Elimininate divs based on inequalities
365 */
366 static struct isl_basic_map *eliminate_divs_ineq(
367 struct isl_basic_map *bmap, int *progress)
368 {
369 int d;
370 int i;
371 unsigned off;
372 struct isl_ctx *ctx;
373
374 if (!bmap)
375 return NULL;
376
377 ctx = bmap->ctx;
378 off = 1 + isl_dim_total(bmap->dim);
379
380 for (d = bmap->n_div - 1; d >= 0 ; --d) {
381 for (i = 0; i < bmap->n_eq; ++i)
382 if (!isl_int_is_zero(bmap->eq[i][off + d]))
383 break;
384 if (i < bmap->n_eq)
385 continue;
386 for (i = 0; i < bmap->n_ineq; ++i)
387 if (isl_int_abs_gt(bmap->ineq[i][off + d], ctx->one))
388 break;
389 if (i < bmap->n_ineq)
390 continue;
391 *progress = 1;
392 bmap = isl_basic_map_eliminate_vars(bmap, (off-1)+d, 1);
393 if (F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
394 break;
395 bmap = isl_basic_map_drop_div(bmap, d);
396 if (!bmap)
397 break;
398 }
399 return bmap;
400 }
401
402 static void eliminate_var_using_equality(struct isl_basic_map *bmap,
403 unsigned pos, isl_int *eq, int *progress)
404 {
405 unsigned total;
406 int k;
407 int contains_divs;
408
409 total = isl_basic_map_total_dim(bmap);
410 contains_divs =
411 isl_seq_first_non_zero(eq + 1 + isl_dim_total(bmap->dim),
412 bmap->n_div) != -1;
413 for (k = 0; k < bmap->n_eq; ++k) {
414 if (bmap->eq[k] == eq)
415 continue;
416 if (isl_int_is_zero(bmap->eq[k][1+pos]))
417 continue;
418 if (progress)
419 *progress = 1;
420 isl_seq_elim(bmap->eq[k], eq, 1+pos, 1+total, NULL);
421 }
422
423 for (k = 0; k < bmap->n_ineq; ++k) {
424 if (isl_int_is_zero(bmap->ineq[k][1+pos]))
425 continue;
426 if (progress)
427 *progress = 1;
428 isl_seq_elim(bmap->ineq[k], eq, 1+pos, 1+total, NULL);
429 F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);
430 }
431
432 for (k = 0; k < bmap->n_div; ++k) {
433 if (isl_int_is_zero(bmap->div[k][0]))
434 continue;
435 if (isl_int_is_zero(bmap->div[k][1+1+pos]))
436 continue;
437 if (progress)
438 *progress = 1;
439 /* We need to be careful about circular definitions,
440 * so for now we just remove the definition of div k
441 * if the equality contains any divs.
442 */
443 if (contains_divs)
444 isl_seq_clr(bmap->div[k], 1 + total);
445 else
446 isl_seq_elim(bmap->div[k]+1, eq,
447 1+pos, 1+total, &bmap->div[k][0]);
448 F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);
449 }
450 }
451
452 struct isl_basic_map *isl_basic_map_gauss(
453 struct isl_basic_map *bmap, int *progress)
454 {
455 int k;
456 int done;
457 int last_var;
458 unsigned total_var;
459 unsigned total;
460
461 if (!bmap)
462 return NULL;
463
464 total = isl_basic_map_total_dim(bmap);
465 total_var = total - bmap->n_div;
466
467 last_var = total - 1;
468 for (done = 0; done < bmap->n_eq; ++done) {
469 for (; last_var >= 0; --last_var) {
470 for (k = done; k < bmap->n_eq; ++k)
471 if (!isl_int_is_zero(bmap->eq[k][1+last_var]))
472 break;
473 if (k < bmap->n_eq)
474 break;
475 }
476 if (last_var < 0)
477 break;
478 if (k != done)
479 swap_equality(bmap, k, done);
480 if (isl_int_is_neg(bmap->eq[done][1+last_var]))
481 isl_seq_neg(bmap->eq[done], bmap->eq[done], 1+total);
482
483 eliminate_var_using_equality(bmap, last_var, bmap->eq[done],
484 progress);
485
486 if (last_var >= total_var &&
487 isl_int_is_zero(bmap->div[last_var - total_var][0])) {
488 unsigned div = last_var - total_var;
489 isl_seq_neg(bmap->div[div]+1, bmap->eq[done], 1+total);
490 isl_int_set_si(bmap->div[div][1+1+last_var], 0);
491 isl_int_set(bmap->div[div][0],
492 bmap->eq[done][1+last_var]);
493 F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);
494 }
495 }
496 if (done == bmap->n_eq)
497 return bmap;
498 for (k = done; k < bmap->n_eq; ++k) {
499 if (isl_int_is_zero(bmap->eq[k][0]))
500 continue;
501 return isl_basic_map_set_to_empty(bmap);
502 }
503 isl_basic_map_free_equality(bmap, bmap->n_eq-done);
504 return bmap;
505 }
506
507 struct isl_basic_set *isl_basic_set_gauss(
508 struct isl_basic_set *bset, int *progress)
509 {
510 return (struct isl_basic_set*)isl_basic_map_gauss(
511 (struct isl_basic_map *)bset, progress);
512 }
513
514
515 static unsigned int round_up(unsigned int v)
516 {
517 int old_v = v;
518
519 while (v) {
520 old_v = v;
521 v ^= v & -v;
522 }
523 return old_v << 1;
524 }
525
526 static int hash_index(isl_int ***index, unsigned int size, int bits,
527 struct isl_basic_map *bmap, int k)
528 {
529 int h;
530 unsigned total = isl_basic_map_total_dim(bmap);
531 uint32_t hash = isl_seq_get_hash_bits(bmap->ineq[k]+1, total, bits);
532 for (h = hash; index[h]; h = (h+1) % size)
533 if (&bmap->ineq[k] != index[h] &&
534 isl_seq_eq(bmap->ineq[k]+1, index[h][0]+1, total))
535 break;
536 return h;
537 }
538
539 static int set_hash_index(isl_int ***index, unsigned int size, int bits,
540 struct isl_basic_set *bset, int k)
541 {
542 return hash_index(index, size, bits, (struct isl_basic_map *)bset, k);
543 }
544
545 /* If we can eliminate more than one div, then we need to make
546 * sure we do it from last div to first div, in order not to
547 * change the position of the other divs that still need to
548 * be removed.
549 */
550 static struct isl_basic_map *remove_duplicate_divs(
551 struct isl_basic_map *bmap, int *progress)
552 {
553 unsigned int size;
554 int *index;
555 int *elim_for;
556 int k, l, h;
557 int bits;
558 struct isl_blk eq;
559 unsigned total_var = isl_dim_total(bmap->dim);
560 unsigned total = total_var + bmap->n_div;
561 struct isl_ctx *ctx;
562
563 if (bmap->n_div <= 1)
564 return bmap;
565
566 ctx = bmap->ctx;
567 for (k = bmap->n_div - 1; k >= 0; --k)
568 if (!isl_int_is_zero(bmap->div[k][0]))
569 break;
570 if (k <= 0)
571 return bmap;
572
573 elim_for = isl_calloc_array(ctx, int, bmap->n_div);
574 size = round_up(4 * bmap->n_div / 3 - 1);
575 bits = ffs(size) - 1;
576 index = isl_calloc_array(ctx, int, size);
577 if (!index)
578 return bmap;
579 eq = isl_blk_alloc(ctx, 1+total);
580 if (isl_blk_is_error(eq))
581 goto out;
582
583 isl_seq_clr(eq.data, 1+total);
584 index[isl_seq_get_hash_bits(bmap->div[k], 2+total, bits)] = k + 1;
585 for (--k; k >= 0; --k) {
586 uint32_t hash;
587
588 if (isl_int_is_zero(bmap->div[k][0]))
589 continue;
590
591 hash = isl_seq_get_hash_bits(bmap->div[k], 2+total, bits);
592 for (h = hash; index[h]; h = (h+1) % size)
593 if (isl_seq_eq(bmap->div[k],
594 bmap->div[index[h]-1], 2+total))
595 break;
596 if (index[h]) {
597 *progress = 1;
598 l = index[h] - 1;
599 elim_for[l] = k + 1;
600 }
601 index[h] = k+1;
602 }
603 for (l = bmap->n_div - 1; l >= 0; --l) {
604 if (!elim_for[l])
605 continue;
606 k = elim_for[l] - 1;
607 isl_int_set_si(eq.data[1+total_var+k], -1);
608 isl_int_set_si(eq.data[1+total_var+l], 1);
609 eliminate_div(bmap, eq.data, l);
610 isl_int_set_si(eq.data[1+total_var+k], 0);
611 isl_int_set_si(eq.data[1+total_var+l], 0);
612 }
613
614 isl_blk_free(ctx, eq);
615 out:
616 free(index);
617 free(elim_for);
618 return bmap;
619 }
620
621 /* Normalize divs that appear in equalities.
622 *
623 * In particular, we assume that bmap contains some equalities
624 * of the form
625 *
626 * a x = m * e_i
627 *
628 * and we want to replace the set of e_i by a minimal set and
629 * such that the new e_i have a canonical representation in terms
630 * of the vector x.
631 * If any of the equalities involves more than one divs, then
632 * we currently simply bail out.
633 *
634 * Let us first additionally assume that all equalities involve
635 * a div. The equalities then express modulo constraints on the
636 * remaining variables and we can use "parameter compression"
637 * to find a minimal set of constraints. The result is a transformation
638 *
639 * x = T(x') = x_0 + G x'
640 *
641 * with G a lower-triangular matrix with all elements below the diagonal
642 * non-negative and smaller than the diagonal element on the same row.
643 * We first normalize x_0 by making the same property hold in the affine
644 * T matrix.
645 * The rows i of G with a 1 on the diagonal do not impose any modulo
646 * constraint and simply express x_i = x'_i.
647 * For each of the remaining rows i, we introduce a div and a corresponding
648 * equality. In particular
649 *
650 * g_ii e_j = x_i - g_i(x')
651 *
652 * where each x'_k is replaced either by x_k (if g_kk = 1) or the
653 * corresponding div (if g_kk != 1).
654 *
655 * If there are any equalities not involving any div, then we
656 * first apply a variable compression on the variables x:
657 *
658 * x = C x'' x'' = C_2 x
659 *
660 * and perform the above parameter compression on A C instead of on A.
661 * The resulting compression is then of the form
662 *
663 * x'' = T(x') = x_0 + G x'
664 *
665 * and in constructing the new divs and the corresponding equalities,
666 * we have to replace each x'', i.e., the x'_k with (g_kk = 1),
667 * by the corresponding row from C_2.
668 */
669 static struct isl_basic_map *normalize_divs(
670 struct isl_basic_map *bmap, int *progress)
671 {
672 int i, j, k;
673 int total;
674 int div_eq;
675 struct isl_mat *B;
676 struct isl_vec *d;
677 struct isl_mat *T = NULL;
678 struct isl_mat *C = NULL;
679 struct isl_mat *C2 = NULL;
680 isl_int v;
681 int *pos;
682 int dropped, needed;
683
684 if (!bmap)
685 return NULL;
686
687 if (bmap->n_div == 0)
688 return bmap;
689
690 if (bmap->n_eq == 0)
691 return bmap;
692
693 if (F_ISSET(bmap, ISL_BASIC_MAP_NORMALIZED_DIVS))
694 return bmap;
695
696 total = isl_dim_total(bmap->dim);
697 for (i = 0, j = bmap->n_div-1; i < bmap->n_eq; ++i) {
698 while (j >= 0 && isl_int_is_zero(bmap->eq[i][1 + total + j]))
699 --j;
700 if (j < 0)
701 break;
702 if (isl_seq_first_non_zero(bmap->eq[i] + 1 + total, j) != -1)
703 goto done;
704 }
705 div_eq = i;
706 if (div_eq == 0)
707 return bmap;
708
709 if (div_eq < bmap->n_eq) {
710 B = isl_mat_sub_alloc(bmap->ctx, bmap->eq, div_eq,
711 bmap->n_eq - div_eq, 0, 1 + total);
712 C = isl_mat_variable_compression(bmap->ctx, B, &C2);
713 if (!C || !C2)
714 goto error;
715 if (C->n_col == 0) {
716 bmap = isl_basic_map_set_to_empty(bmap);
717 isl_mat_free(bmap->ctx, C);
718 isl_mat_free(bmap->ctx, C2);
719 goto done;
720 }
721 }
722
723 d = isl_vec_alloc(bmap->ctx, div_eq);
724 if (!d)
725 goto error;
726 for (i = 0, j = bmap->n_div-1; i < div_eq; ++i) {
727 while (j >= 0 && isl_int_is_zero(bmap->eq[i][1 + total + j]))
728 --j;
729 isl_int_set(d->block.data[i], bmap->eq[i][1 + total + j]);
730 }
731 B = isl_mat_sub_alloc(bmap->ctx, bmap->eq, 0, div_eq, 0, 1 + total);
732
733 if (C) {
734 B = isl_mat_product(bmap->ctx, B, C);
735 C = NULL;
736 }
737
738 T = isl_mat_parameter_compression(bmap->ctx, B, d);
739 if (!T)
740 goto error;
741 if (T->n_col == 0) {
742 bmap = isl_basic_map_set_to_empty(bmap);
743 isl_mat_free(bmap->ctx, C2);
744 isl_mat_free(bmap->ctx, T);
745 goto done;
746 }
747 isl_int_init(v);
748 for (i = 0; i < T->n_row - 1; ++i) {
749 isl_int_fdiv_q(v, T->row[1 + i][0], T->row[1 + i][1 + i]);
750 if (isl_int_is_zero(v))
751 continue;
752 isl_mat_col_submul(T, 0, v, 1 + i);
753 }
754 isl_int_clear(v);
755 pos = isl_alloc_array(bmap->ctx, int, T->n_row);
756 /* We have to be careful because dropping equalities may reorder them */
757 dropped = 0;
758 for (j = bmap->n_div - 1; j >= 0; --j) {
759 for (i = 0; i < bmap->n_eq; ++i)
760 if (!isl_int_is_zero(bmap->eq[i][1 + total + j]))
761 break;
762 if (i < bmap->n_eq) {
763 bmap = isl_basic_map_drop_div(bmap, j);
764 isl_basic_map_drop_equality(bmap, i);
765 ++dropped;
766 }
767 }
768 pos[0] = 0;
769 needed = 0;
770 for (i = 1; i < T->n_row; ++i) {
771 if (isl_int_is_one(T->row[i][i]))
772 pos[i] = i;
773 else
774 needed++;
775 }
776 if (needed > dropped) {
777 bmap = isl_basic_map_extend_dim(bmap, isl_dim_copy(bmap->dim),
778 needed, needed, 0);
779 if (!bmap)
780 goto error;
781 }
782 for (i = 1; i < T->n_row; ++i) {
783 if (isl_int_is_one(T->row[i][i]))
784 continue;
785 k = isl_basic_map_alloc_div(bmap);
786 pos[i] = 1 + total + k;
787 isl_seq_clr(bmap->div[k] + 1, 1 + total + bmap->n_div);
788 isl_int_set(bmap->div[k][0], T->row[i][i]);
789 if (C2)
790 isl_seq_cpy(bmap->div[k] + 1, C2->row[i], 1 + total);
791 else
792 isl_int_set_si(bmap->div[k][1 + i], 1);
793 for (j = 0; j < i; ++j) {
794 if (isl_int_is_zero(T->row[i][j]))
795 continue;
796 if (pos[j] < T->n_row && C2)
797 isl_seq_submul(bmap->div[k] + 1, T->row[i][j],
798 C2->row[pos[j]], 1 + total);
799 else
800 isl_int_neg(bmap->div[k][1 + pos[j]],
801 T->row[i][j]);
802 }
803 j = isl_basic_map_alloc_equality(bmap);
804 isl_seq_neg(bmap->eq[j], bmap->div[k]+1, 1+total+bmap->n_div);
805 isl_int_set(bmap->eq[j][pos[i]], bmap->div[k][0]);
806 }
807 free(pos);
808 isl_mat_free(bmap->ctx, C2);
809 isl_mat_free(bmap->ctx, T);
810
811 *progress = 1;
812 done:
813 F_SET(bmap, ISL_BASIC_MAP_NORMALIZED_DIVS);
814
815 return bmap;
816 error:
817 isl_mat_free(bmap->ctx, C);
818 isl_mat_free(bmap->ctx, C2);
819 isl_mat_free(bmap->ctx, T);
820 return bmap;
821 }
822
823 static struct isl_basic_map *remove_duplicate_constraints(
824 struct isl_basic_map *bmap, int *progress)
825 {
826 unsigned int size;
827 isl_int ***index;
828 int k, l, h;
829 int bits;
830 unsigned total = isl_basic_map_total_dim(bmap);
831 isl_int sum;
832
833 if (bmap->n_ineq <= 1)
834 return bmap;
835
836 size = round_up(4 * (bmap->n_ineq+1) / 3 - 1);
837 bits = ffs(size) - 1;
838 index = isl_calloc_array(ctx, isl_int **, size);
839 if (!index)
840 return bmap;
841
842 index[isl_seq_get_hash_bits(bmap->ineq[0]+1, total, bits)] = &bmap->ineq[0];
843 for (k = 1; k < bmap->n_ineq; ++k) {
844 h = hash_index(index, size, bits, bmap, k);
845 if (!index[h]) {
846 index[h] = &bmap->ineq[k];
847 continue;
848 }
849 if (progress)
850 *progress = 1;
851 l = index[h] - &bmap->ineq[0];
852 if (isl_int_lt(bmap->ineq[k][0], bmap->ineq[l][0]))
853 swap_inequality(bmap, k, l);
854 isl_basic_map_drop_inequality(bmap, k);
855 --k;
856 }
857 isl_int_init(sum);
858 for (k = 0; k < bmap->n_ineq-1; ++k) {
859 isl_seq_neg(bmap->ineq[k]+1, bmap->ineq[k]+1, total);
860 h = hash_index(index, size, bits, bmap, k);
861 isl_seq_neg(bmap->ineq[k]+1, bmap->ineq[k]+1, total);
862 if (!index[h])
863 continue;
864 l = index[h] - &bmap->ineq[0];
865 isl_int_add(sum, bmap->ineq[k][0], bmap->ineq[l][0]);
866 if (isl_int_is_pos(sum))
867 continue;
868 if (isl_int_is_zero(sum)) {
869 /* We need to break out of the loop after these
870 * changes since the contents of the hash
871 * will no longer be valid.
872 * Plus, we probably we want to regauss first.
873 */
874 isl_basic_map_drop_inequality(bmap, l);
875 isl_basic_map_inequality_to_equality(bmap, k);
876 } else
877 bmap = isl_basic_map_set_to_empty(bmap);
878 break;
879 }
880 isl_int_clear(sum);
881
882 free(index);
883 return bmap;
884 }
885
886
887 struct isl_basic_map *isl_basic_map_simplify(struct isl_basic_map *bmap)
888 {
889 int progress = 1;
890 if (!bmap)
891 return NULL;
892 while (progress) {
893 progress = 0;
894 bmap = normalize_constraints(bmap);
895 bmap = eliminate_divs_eq(bmap, &progress);
896 bmap = eliminate_divs_ineq(bmap, &progress);
897 bmap = isl_basic_map_gauss(bmap, &progress);
898 /* requires equalities in normal form */
899 bmap = normalize_divs(bmap, &progress);
900 bmap = remove_duplicate_divs(bmap, &progress);
901 bmap = remove_duplicate_constraints(bmap, &progress);
902 }
903 return bmap;
904 }
905
906 struct isl_basic_set *isl_basic_set_simplify(struct isl_basic_set *bset)
907 {
908 return (struct isl_basic_set *)
909 isl_basic_map_simplify((struct isl_basic_map *)bset);
910 }
911
912
913 /* If the only constraints a div d=floor(f/m)
914 * appears in are its two defining constraints
915 *
916 * f - m d >=0
917 * -(f - (m - 1)) + m d >= 0
918 *
919 * then it can safely be removed.
920 */
921 static int div_is_redundant(struct isl_basic_map *bmap, int div)
922 {
923 int i;
924 unsigned pos = 1 + isl_dim_total(bmap->dim) + div;
925
926 for (i = 0; i < bmap->n_eq; ++i)
927 if (!isl_int_is_zero(bmap->eq[i][pos]))
928 return 0;
929
930 for (i = 0; i < bmap->n_ineq; ++i) {
931 if (isl_int_is_zero(bmap->ineq[i][pos]))
932 continue;
933 if (isl_int_eq(bmap->ineq[i][pos], bmap->div[div][0])) {
934 int neg;
935 isl_int_sub(bmap->div[div][1],
936 bmap->div[div][1], bmap->div[div][0]);
937 isl_int_add_ui(bmap->div[div][1], bmap->div[div][1], 1);
938 neg = isl_seq_is_neg(bmap->ineq[i], bmap->div[div]+1, pos);
939 isl_int_sub_ui(bmap->div[div][1], bmap->div[div][1], 1);
940 isl_int_add(bmap->div[div][1],
941 bmap->div[div][1], bmap->div[div][0]);
942 if (!neg)
943 return 0;
944 if (isl_seq_first_non_zero(bmap->ineq[i]+pos+1,
945 bmap->n_div-div-1) != -1)
946 return 0;
947 } else if (isl_int_abs_eq(bmap->ineq[i][pos], bmap->div[div][0])) {
948 if (!isl_seq_eq(bmap->ineq[i], bmap->div[div]+1, pos))
949 return 0;
950 if (isl_seq_first_non_zero(bmap->ineq[i]+pos+1,
951 bmap->n_div-div-1) != -1)
952 return 0;
953 } else
954 return 0;
955 }
956
957 for (i = 0; i < bmap->n_div; ++i)
958 if (!isl_int_is_zero(bmap->div[i][1+pos]))
959 return 0;
960
961 return 1;
962 }
963
964 /*
965 * Remove divs that don't occur in any of the constraints or other divs.
966 * These can arise when dropping some of the variables in a quast
967 * returned by piplib.
968 */
969 static struct isl_basic_map *remove_redundant_divs(struct isl_basic_map *bmap)
970 {
971 int i;
972
973 if (!bmap)
974 return NULL;
975
976 for (i = bmap->n_div-1; i >= 0; --i) {
977 if (!div_is_redundant(bmap, i))
978 continue;
979 bmap = isl_basic_map_drop_div(bmap, i);
980 }
981 return bmap;
982 }
983
984 struct isl_basic_map *isl_basic_map_finalize(struct isl_basic_map *bmap)
985 {
986 bmap = remove_redundant_divs(bmap);
987 if (!bmap)
988 return NULL;
989 F_SET(bmap, ISL_BASIC_SET_FINAL);
990 return bmap;
991 }
992
993 struct isl_basic_set *isl_basic_set_finalize(struct isl_basic_set *bset)
994 {
995 return (struct isl_basic_set *)
996 isl_basic_map_finalize((struct isl_basic_map *)bset);
997 }
998
999 struct isl_set *isl_set_finalize(struct isl_set *set)
1000 {
1001 int i;
1002
1003 if (!set)
1004 return NULL;
1005 for (i = 0; i < set->n; ++i) {
1006 set->p[i] = isl_basic_set_finalize(set->p[i]);
1007 if (!set->p[i])
1008 goto error;
1009 }
1010 return set;
1011 error:
1012 isl_set_free(set);
1013 return NULL;
1014 }
1015
1016 struct isl_map *isl_map_finalize(struct isl_map *map)
1017 {
1018 int i;
1019
1020 if (!map)
1021 return NULL;
1022 for (i = 0; i < map->n; ++i) {
1023 map->p[i] = isl_basic_map_finalize(map->p[i]);
1024 if (!map->p[i])
1025 goto error;
1026 }
1027 F_CLR(map, ISL_MAP_NORMALIZED);
1028 return map;
1029 error:
1030 isl_map_free(map);
1031 return NULL;
1032 }
1033
1034
1035 /* Remove any div that is defined in terms of the given variable.
1036 */
1037 static struct isl_basic_map *remove_dependent_vars(struct isl_basic_map *bmap,
1038 int pos)
1039 {
1040 int i;
1041 unsigned dim = isl_dim_total(bmap->dim);
1042
1043 for (i = 0; i < bmap->n_div; ++i) {
1044 if (isl_int_is_zero(bmap->div[i][0]))
1045 continue;
1046 if (isl_int_is_zero(bmap->div[i][1+1+pos]))
1047 continue;
1048 bmap = isl_basic_map_eliminate_vars(bmap, dim + i, 1);
1049 if (!bmap)
1050 return NULL;
1051 }
1052 return bmap;
1053 }
1054
1055 /* Eliminate the specified variables from the constraints using
1056 * Fourier-Motzkin. The variables themselves are not removed.
1057 */
1058 struct isl_basic_map *isl_basic_map_eliminate_vars(
1059 struct isl_basic_map *bmap, unsigned pos, unsigned n)
1060 {
1061 int d;
1062 int i, j, k;
1063 unsigned total;
1064
1065 if (n == 0)
1066 return bmap;
1067 if (!bmap)
1068 return NULL;
1069 total = isl_basic_map_total_dim(bmap);
1070
1071 bmap = isl_basic_map_cow(bmap);
1072 for (d = pos + n - 1; d >= 0 && d >= pos; --d) {
1073 int n_lower, n_upper;
1074 bmap = remove_dependent_vars(bmap, d);
1075 if (!bmap)
1076 return NULL;
1077 if (d >= total - bmap->n_div)
1078 isl_seq_clr(bmap->div[d-(total-bmap->n_div)], 2+total);
1079 for (i = 0; i < bmap->n_eq; ++i) {
1080 if (isl_int_is_zero(bmap->eq[i][1+d]))
1081 continue;
1082 eliminate_var_using_equality(bmap, d, bmap->eq[i], NULL);
1083 isl_basic_map_drop_equality(bmap, i);
1084 break;
1085 }
1086 if (i < bmap->n_eq)
1087 continue;
1088 n_lower = 0;
1089 n_upper = 0;
1090 for (i = 0; i < bmap->n_ineq; ++i) {
1091 if (isl_int_is_pos(bmap->ineq[i][1+d]))
1092 n_lower++;
1093 else if (isl_int_is_neg(bmap->ineq[i][1+d]))
1094 n_upper++;
1095 }
1096 bmap = isl_basic_map_extend_constraints(bmap,
1097 0, n_lower * n_upper);
1098 for (i = bmap->n_ineq - 1; i >= 0; --i) {
1099 int last;
1100 if (isl_int_is_zero(bmap->ineq[i][1+d]))
1101 continue;
1102 last = -1;
1103 for (j = 0; j < i; ++j) {
1104 if (isl_int_is_zero(bmap->ineq[j][1+d]))
1105 continue;
1106 last = j;
1107 if (isl_int_sgn(bmap->ineq[i][1+d]) ==
1108 isl_int_sgn(bmap->ineq[j][1+d]))
1109 continue;
1110 k = isl_basic_map_alloc_inequality(bmap);
1111 if (k < 0)
1112 goto error;
1113 isl_seq_cpy(bmap->ineq[k], bmap->ineq[i],
1114 1+total);
1115 isl_seq_elim(bmap->ineq[k], bmap->ineq[j],
1116 1+d, 1+total, NULL);
1117 }
1118 isl_basic_map_drop_inequality(bmap, i);
1119 i = last + 1;
1120 }
1121 if (n_lower > 0 && n_upper > 0) {
1122 bmap = normalize_constraints(bmap);
1123 bmap = remove_duplicate_constraints(bmap, NULL);
1124 bmap = isl_basic_map_gauss(bmap, NULL);
1125 bmap = isl_basic_map_convex_hull(bmap);
1126 if (!bmap)
1127 goto error;
1128 if (F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
1129 break;
1130 }
1131 }
1132 F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);
1133 return bmap;
1134 error:
1135 isl_basic_map_free(bmap);
1136 return NULL;
1137 }
1138
1139 struct isl_basic_set *isl_basic_set_eliminate_vars(
1140 struct isl_basic_set *bset, unsigned pos, unsigned n)
1141 {
1142 return (struct isl_basic_set *)isl_basic_map_eliminate_vars(
1143 (struct isl_basic_map *)bset, pos, n);
1144 }
1145
1146 static void compute_elimination_index(struct isl_basic_map *bmap, int *elim)
1147 {
1148 int d, i;
1149 unsigned total;
1150
1151 total = isl_dim_total(bmap->dim);
1152 for (d = 0; d < total; ++d)
1153 elim[d] = -1;
1154 for (d = total - 1, i = 0; d >= 0 && i < bmap->n_eq; ++i) {
1155 for (; d >= 0; --d) {
1156 if (isl_int_is_zero(bmap->eq[i][1+d]))
1157 continue;
1158 elim[d] = i;
1159 break;
1160 }
1161 }
1162 }
1163
1164 static void set_compute_elimination_index(struct isl_basic_set *bset, int *elim)
1165 {
1166 return compute_elimination_index((struct isl_basic_map *)bset, elim);
1167 }
1168
1169 static int reduced_using_equalities(isl_int *dst, isl_int *src,
1170 struct isl_basic_map *bmap, int *elim)
1171 {
1172 int d, i;
1173 int copied = 0;
1174 unsigned total;
1175
1176 total = isl_dim_total(bmap->dim);
1177 for (d = total - 1; d >= 0; --d) {
1178 if (isl_int_is_zero(src[1+d]))
1179 continue;
1180 if (elim[d] == -1)
1181 continue;
1182 if (!copied) {
1183 isl_seq_cpy(dst, src, 1 + total);
1184 copied = 1;
1185 }
1186 isl_seq_elim(dst, bmap->eq[elim[d]], 1 + d, 1 + total, NULL);
1187 }
1188 return copied;
1189 }
1190
1191 static int set_reduced_using_equalities(isl_int *dst, isl_int *src,
1192 struct isl_basic_set *bset, int *elim)
1193 {
1194 return reduced_using_equalities(dst, src,
1195 (struct isl_basic_map *)bset, elim);
1196 }
1197
1198 static struct isl_basic_set *isl_basic_set_reduce_using_equalities(
1199 struct isl_basic_set *bset, struct isl_basic_set *context)
1200 {
1201 int i;
1202 int *elim;
1203
1204 if (!bset || !context)
1205 goto error;
1206
1207 bset = isl_basic_set_cow(bset);
1208 if (!bset)
1209 goto error;
1210
1211 elim = isl_alloc_array(ctx, int, isl_basic_set_n_dim(bset));
1212 if (!elim)
1213 goto error;
1214 set_compute_elimination_index(context, elim);
1215 for (i = 0; i < bset->n_eq; ++i)
1216 set_reduced_using_equalities(bset->eq[i], bset->eq[i],
1217 context, elim);
1218 for (i = 0; i < bset->n_ineq; ++i)
1219 set_reduced_using_equalities(bset->ineq[i], bset->ineq[i],
1220 context, elim);
1221 isl_basic_set_free(context);
1222 free(elim);
1223 bset = isl_basic_set_simplify(bset);
1224 bset = isl_basic_set_finalize(bset);
1225 return bset;
1226 error:
1227 isl_basic_set_free(bset);
1228 isl_basic_set_free(context);
1229 return NULL;
1230 }
1231
1232 static struct isl_basic_set *remove_shifted_constraints(
1233 struct isl_basic_set *bset, struct isl_basic_set *context)
1234 {
1235 unsigned int size;
1236 isl_int ***index;
1237 int bits;
1238 int k, h, l;
1239
1240 if (!bset)
1241 return NULL;
1242
1243 size = round_up(4 * (context->n_ineq+1) / 3 - 1);
1244 bits = ffs(size) - 1;
1245 index = isl_calloc_array(ctx, isl_int **, size);
1246 if (!index)
1247 return bset;
1248
1249 for (k = 0; k < context->n_ineq; ++k) {
1250 h = set_hash_index(index, size, bits, context, k);
1251 index[h] = &context->ineq[k];
1252 }
1253 for (k = 0; k < bset->n_ineq; ++k) {
1254 h = set_hash_index(index, size, bits, bset, k);
1255 if (!index[h])
1256 continue;
1257 l = index[h] - &context->ineq[0];
1258 if (isl_int_lt(bset->ineq[k][0], context->ineq[l][0]))
1259 continue;
1260 bset = isl_basic_set_cow(bset);
1261 if (!bset)
1262 goto error;
1263 isl_basic_set_drop_inequality(bset, k);
1264 --k;
1265 }
1266 free(index);
1267 return bset;
1268 error:
1269 free(index);
1270 return bset;
1271 }
1272
1273 static struct isl_basic_set *uset_gist(struct isl_basic_set *bset,
1274 struct isl_basic_set *context);
1275
1276 static struct isl_basic_set *uset_gist_context_eq(struct isl_basic_set *bset,
1277 struct isl_basic_set *context)
1278 {
1279 struct isl_mat *T;
1280 struct isl_mat *T2;
1281 struct isl_ctx *ctx = context->ctx;
1282 struct isl_basic_set *reduced_context;
1283 reduced_context = isl_basic_set_remove_equalities(
1284 isl_basic_set_copy(context), &T, &T2);
1285 if (!reduced_context)
1286 goto error;
1287 bset = isl_basic_set_preimage(ctx, bset, T);
1288 bset = uset_gist(bset, reduced_context);
1289 bset = isl_basic_set_preimage(ctx, bset, T2);
1290 bset = isl_basic_set_reduce_using_equalities(bset, context);
1291 return bset;
1292 error:
1293 isl_basic_set_free(context);
1294 isl_basic_set_free(bset);
1295 return NULL;
1296 }
1297
1298 static struct isl_basic_set *uset_gist_set_eq(struct isl_basic_set *bset,
1299 struct isl_basic_set *context)
1300 {
1301 struct isl_mat *T;
1302 struct isl_mat *T2;
1303 struct isl_ctx *ctx = context->ctx;
1304 struct isl_basic_set *affine_hull = NULL;
1305
1306 affine_hull = isl_basic_set_copy(bset);
1307 affine_hull = isl_basic_set_cow(affine_hull);
1308 if (!affine_hull)
1309 goto error;
1310 isl_basic_set_free_inequality(affine_hull, affine_hull->n_ineq);
1311
1312 bset = isl_basic_set_remove_equalities(bset, &T, &T2);
1313 if (!bset)
1314 goto error;
1315 context = isl_basic_set_preimage(ctx, context, T);
1316 bset = uset_gist(bset, context);
1317 bset = isl_basic_set_preimage(ctx, bset, T2);
1318 bset = isl_basic_set_intersect(bset, affine_hull);
1319 return bset;
1320 error:
1321 isl_basic_set_free(affine_hull);
1322 isl_basic_set_free(context);
1323 isl_basic_set_free(bset);
1324 return NULL;
1325 }
1326
1327 /* Remove all information from bset that is redundant in the context
1328 * of context. In particular, equalities that are linear combinations
1329 * of those in context are removed. Then the inequalities that are
1330 * redundant in the context of the equalities and inequalities of
1331 * context are removed.
1332 */
1333 static struct isl_basic_set *uset_gist(struct isl_basic_set *bset,
1334 struct isl_basic_set *context)
1335 {
1336 int i;
1337 isl_int opt;
1338 struct isl_basic_set *combined;
1339 struct isl_ctx *ctx;
1340
1341 if (!bset || !context)
1342 goto error;
1343
1344 if (context->n_eq > 0)
1345 return uset_gist_context_eq(bset, context);
1346 if (!context->n_ineq)
1347 goto done;
1348 if (bset->n_eq > 0)
1349 return uset_gist_set_eq(bset, context);
1350 bset = remove_shifted_constraints(bset, context);
1351 combined = isl_basic_set_extend_constraints(isl_basic_set_copy(bset),
1352 context->n_eq, context->n_ineq);
1353 context = isl_basic_set_add_constraints(combined, context, 0);
1354 if (!context)
1355 goto error;
1356 ctx = context->ctx;
1357 isl_int_init(opt);
1358 for (i = bset->n_ineq-1; i >= 0; --i) {
1359 int redundant;
1360 set_swap_inequality(context, i, context->n_ineq-1);
1361 context->n_ineq--;
1362 redundant = isl_basic_set_constraint_is_redundant(&context,
1363 context->ineq[context->n_ineq], &opt, NULL);
1364 if (redundant == -1) {
1365 isl_int_clear(opt);
1366 goto error;
1367 }
1368 if (F_ISSET(context, ISL_BASIC_MAP_EMPTY)) {
1369 bset = isl_basic_set_set_to_empty(bset);
1370 break;
1371 }
1372 context->n_ineq++;
1373 set_swap_inequality(context, i, context->n_ineq-1);
1374 if (redundant) {
1375 isl_basic_set_drop_inequality(context, i);
1376 isl_basic_set_drop_inequality(bset, i);
1377 }
1378 }
1379 isl_int_clear(opt);
1380 done:
1381 isl_basic_set_free(context);
1382 return bset;
1383 error:
1384 isl_basic_set_free(context);
1385 isl_basic_set_free(bset);
1386 return NULL;
1387 }
1388
1389 struct isl_basic_map *isl_basic_map_gist(struct isl_basic_map *bmap,
1390 struct isl_basic_map *context)
1391 {
1392 struct isl_basic_set *bset;
1393
1394 if (!bmap || !context)
1395 goto error;
1396
1397 context = isl_basic_map_align_divs(context, bmap);
1398 bmap = isl_basic_map_align_divs(bmap, context);
1399
1400 bset = uset_gist(isl_basic_map_underlying_set(isl_basic_map_copy(bmap)),
1401 isl_basic_map_underlying_set(context));
1402
1403 return isl_basic_map_overlying_set(bset, bmap);
1404 error:
1405 isl_basic_map_free(bmap);
1406 isl_basic_map_free(context);
1407 return NULL;
1408 }
1409
1410 /*
1411 * Assumes context has no implicit divs.
1412 */
1413 struct isl_map *isl_map_gist(struct isl_map *map, struct isl_basic_map *context)
1414 {
1415 int i;
1416
1417 map = isl_map_cow(map);
1418 if (!map || !context)
1419 return NULL;
1420 isl_assert(map->ctx, isl_dim_equal(map->dim, context->dim), goto error);
1421 map = isl_map_compute_divs(map);
1422 for (i = 0; i < map->n; ++i)
1423 context = isl_basic_map_align_divs(context, map->p[i]);
1424 for (i = 0; i < map->n; ++i) {
1425 map->p[i] = isl_basic_map_gist(map->p[i],
1426 isl_basic_map_copy(context));
1427 if (!map->p[i])
1428 goto error;
1429 }
1430 isl_basic_map_free(context);
1431 F_CLR(map, ISL_MAP_NORMALIZED);
1432 return map;
1433 error:
1434 isl_map_free(map);
1435 isl_basic_map_free(context);
1436 return NULL;
1437 }
1438
1439 struct isl_basic_set *isl_basic_set_gist(struct isl_basic_set *bset,
1440 struct isl_basic_set *context)
1441 {
1442 return (struct isl_basic_set *)isl_basic_map_gist(
1443 (struct isl_basic_map *)bset, (struct isl_basic_map *)context);
1444 }
1445
1446 struct isl_set *isl_set_gist(struct isl_set *set, struct isl_basic_set *context)
1447 {
1448 return (struct isl_set *)isl_map_gist((struct isl_map *)set,
1449 (struct isl_basic_map *)context);
1450 }
1451
1452 /* Quick check to see if two basic maps are disjoint.
1453 * In particular, we reduce the equalities and inequalities of
1454 * one basic map in the context of the equalities of the other
1455 * basic map and check if we get a contradiction.
1456 */
1457 int isl_basic_map_fast_is_disjoint(struct isl_basic_map *bmap1,
1458 struct isl_basic_map *bmap2)
1459 {
1460 struct isl_vec *v = NULL;
1461 int *elim = NULL;
1462 unsigned total;
1463 int d, i;
1464
1465 if (!bmap1 || !bmap2)
1466 return -1;
1467 isl_assert(bmap1->ctx, isl_dim_equal(bmap1->dim, bmap2->dim),
1468 return -1);
1469 if (bmap1->n_div || bmap2->n_div)
1470 return 0;
1471 if (!bmap1->n_eq && !bmap2->n_eq)
1472 return 0;
1473
1474 total = isl_dim_total(bmap1->dim);
1475 if (total == 0)
1476 return 0;
1477 v = isl_vec_alloc(bmap1->ctx, 1 + total);
1478 if (!v)
1479 goto error;
1480 elim = isl_alloc_array(bmap1->ctx, int, total);
1481 if (!elim)
1482 goto error;
1483 compute_elimination_index(bmap1, elim);
1484 for (i = 0; i < bmap2->n_eq; ++i) {
1485 int reduced;
1486 reduced = reduced_using_equalities(v->block.data, bmap2->eq[i],
1487 bmap1, elim);
1488 if (reduced && !isl_int_is_zero(v->block.data[0]) &&
1489 isl_seq_first_non_zero(v->block.data + 1, total) == -1)
1490 goto disjoint;
1491 }
1492 for (i = 0; i < bmap2->n_ineq; ++i) {
1493 int reduced;
1494 reduced = reduced_using_equalities(v->block.data,
1495 bmap2->ineq[i], bmap1, elim);
1496 if (reduced && isl_int_is_neg(v->block.data[0]) &&
1497 isl_seq_first_non_zero(v->block.data + 1, total) == -1)
1498 goto disjoint;
1499 }
1500 compute_elimination_index(bmap2, elim);
1501 for (i = 0; i < bmap1->n_ineq; ++i) {
1502 int reduced;
1503 reduced = reduced_using_equalities(v->block.data,
1504 bmap1->ineq[i], bmap2, elim);
1505 if (reduced && isl_int_is_neg(v->block.data[0]) &&
1506 isl_seq_first_non_zero(v->block.data + 1, total) == -1)
1507 goto disjoint;
1508 }
1509 isl_vec_free(bmap1->ctx, v);
1510 free(elim);
1511 return 0;
1512 disjoint:
1513 isl_vec_free(bmap1->ctx, v);
1514 free(elim);
1515 return 1;
1516 error:
1517 isl_vec_free(bmap1->ctx, v);
1518 free(elim);
1519 return -1;
1520 }
1521
1522 int isl_basic_set_fast_is_disjoint(struct isl_basic_set *bset1,
1523 struct isl_basic_set *bset2)
1524 {
1525 return isl_basic_map_fast_is_disjoint((struct isl_basic_map *)bset1,
1526 (struct isl_basic_map *)bset2);
1527 }
1528
1529 int isl_map_fast_is_disjoint(struct isl_map *map1, struct isl_map *map2)
1530 {
1531 int i, j;
1532
1533 if (!map1 || !map2)
1534 return -1;
1535
1536 if (isl_map_fast_is_equal(map1, map2))
1537 return 0;
1538
1539 for (i = 0; i < map1->n; ++i) {
1540 for (j = 0; j < map2->n; ++j) {
1541 int d = isl_basic_map_fast_is_disjoint(map1->p[i],
1542 map2->p[j]);
1543 if (d != 1)
1544 return d;
1545 }
1546 }
1547 return 1;
1548 }
1549
1550 int isl_set_fast_is_disjoint(struct isl_set *set1, struct isl_set *set2)
1551 {
1552 return isl_map_fast_is_disjoint((struct isl_map *)set1,
1553 (struct isl_map *)set2);
1554 }
Integer set library