• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright 2008-2009 Katholieke Universiteit Leuven
3  *
4  * Use of this software is governed by the MIT license
5  *
6  * Written by Sven Verdoolaege, K.U.Leuven, Departement
7  * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
8  */
9 
10 #include <isl_ctx_private.h>
11 #include <isl_map_private.h>
12 #include <isl/ilp.h>
13 #include <isl/union_set.h>
14 #include "isl_sample.h"
15 #include <isl_seq.h>
16 #include "isl_equalities.h"
17 #include <isl_aff_private.h>
18 #include <isl_local_space_private.h>
19 #include <isl_mat_private.h>
20 #include <isl_val_private.h>
21 #include <isl_vec_private.h>
22 #include <isl_lp_private.h>
23 #include <isl_ilp_private.h>
24 
25 /* Given a basic set "bset", construct a basic set U such that for
26  * each element x in U, the whole unit box positioned at x is inside
27  * the given basic set.
28  * Note that U may not contain all points that satisfy this property.
29  *
30  * We simply add the sum of all negative coefficients to the constant
31  * term.  This ensures that if x satisfies the resulting constraints,
32  * then x plus any sum of unit vectors satisfies the original constraints.
33  */
unit_box_base_points(__isl_take isl_basic_set * bset)34 static __isl_give isl_basic_set *unit_box_base_points(
35 	__isl_take isl_basic_set *bset)
36 {
37 	int i, j, k;
38 	struct isl_basic_set *unit_box = NULL;
39 	isl_size total;
40 
41 	if (!bset)
42 		goto error;
43 
44 	if (bset->n_eq != 0) {
45 		isl_space *space = isl_basic_set_get_space(bset);
46 		isl_basic_set_free(bset);
47 		return isl_basic_set_empty(space);
48 	}
49 
50 	total = isl_basic_set_dim(bset, isl_dim_all);
51 	if (total < 0)
52 		goto error;
53 	unit_box = isl_basic_set_alloc_space(isl_basic_set_get_space(bset),
54 					0, 0, bset->n_ineq);
55 
56 	for (i = 0; i < bset->n_ineq; ++i) {
57 		k = isl_basic_set_alloc_inequality(unit_box);
58 		if (k < 0)
59 			goto error;
60 		isl_seq_cpy(unit_box->ineq[k], bset->ineq[i], 1 + total);
61 		for (j = 0; j < total; ++j) {
62 			if (isl_int_is_nonneg(unit_box->ineq[k][1 + j]))
63 				continue;
64 			isl_int_add(unit_box->ineq[k][0],
65 				unit_box->ineq[k][0], unit_box->ineq[k][1 + j]);
66 		}
67 	}
68 
69 	isl_basic_set_free(bset);
70 	return unit_box;
71 error:
72 	isl_basic_set_free(bset);
73 	isl_basic_set_free(unit_box);
74 	return NULL;
75 }
76 
77 /* Find an integer point in "bset", preferably one that is
78  * close to minimizing "f".
79  *
80  * We first check if we can easily put unit boxes inside bset.
81  * If so, we take the best base point of any of the unit boxes we can find
82  * and round it up to the nearest integer.
83  * If not, we simply pick any integer point in "bset".
84  */
initial_solution(__isl_keep isl_basic_set * bset,isl_int * f)85 static __isl_give isl_vec *initial_solution(__isl_keep isl_basic_set *bset,
86 	isl_int *f)
87 {
88 	enum isl_lp_result res;
89 	struct isl_basic_set *unit_box;
90 	struct isl_vec *sol;
91 
92 	unit_box = unit_box_base_points(isl_basic_set_copy(bset));
93 
94 	res = isl_basic_set_solve_lp(unit_box, 0, f, bset->ctx->one,
95 					NULL, NULL, &sol);
96 	if (res == isl_lp_ok) {
97 		isl_basic_set_free(unit_box);
98 		return isl_vec_ceil(sol);
99 	}
100 
101 	isl_basic_set_free(unit_box);
102 
103 	return isl_basic_set_sample_vec(isl_basic_set_copy(bset));
104 }
105 
106 /* Restrict "bset" to those points with values for f in the interval [l, u].
107  */
add_bounds(__isl_take isl_basic_set * bset,isl_int * f,isl_int l,isl_int u)108 static __isl_give isl_basic_set *add_bounds(__isl_take isl_basic_set *bset,
109 	isl_int *f, isl_int l, isl_int u)
110 {
111 	int k;
112 	isl_size total;
113 
114 	total = isl_basic_set_dim(bset, isl_dim_all);
115 	if (total < 0)
116 		return isl_basic_set_free(bset);
117 	bset = isl_basic_set_extend_constraints(bset, 0, 2);
118 
119 	k = isl_basic_set_alloc_inequality(bset);
120 	if (k < 0)
121 		goto error;
122 	isl_seq_cpy(bset->ineq[k], f, 1 + total);
123 	isl_int_sub(bset->ineq[k][0], bset->ineq[k][0], l);
124 
125 	k = isl_basic_set_alloc_inequality(bset);
126 	if (k < 0)
127 		goto error;
128 	isl_seq_neg(bset->ineq[k], f, 1 + total);
129 	isl_int_add(bset->ineq[k][0], bset->ineq[k][0], u);
130 
131 	return bset;
132 error:
133 	isl_basic_set_free(bset);
134 	return NULL;
135 }
136 
137 /* Find an integer point in "bset" that minimizes f (in any) such that
138  * the value of f lies inside the interval [l, u].
139  * Return this integer point if it can be found.
140  * Otherwise, return sol.
141  *
142  * We perform a number of steps until l > u.
143  * In each step, we look for an integer point with value in either
144  * the whole interval [l, u] or half of the interval [l, l+floor(u-l-1/2)].
145  * The choice depends on whether we have found an integer point in the
146  * previous step.  If so, we look for the next point in half of the remaining
147  * interval.
148  * If we find a point, the current solution is updated and u is set
149  * to its value minus 1.
150  * If no point can be found, we update l to the upper bound of the interval
151  * we checked (u or l+floor(u-l-1/2)) plus 1.
152  */
solve_ilp_search(__isl_keep isl_basic_set * bset,isl_int * f,isl_int * opt,__isl_take isl_vec * sol,isl_int l,isl_int u)153 static __isl_give isl_vec *solve_ilp_search(__isl_keep isl_basic_set *bset,
154 	isl_int *f, isl_int *opt, __isl_take isl_vec *sol, isl_int l, isl_int u)
155 {
156 	isl_int tmp;
157 	int divide = 1;
158 
159 	isl_int_init(tmp);
160 
161 	while (isl_int_le(l, u)) {
162 		struct isl_basic_set *slice;
163 		struct isl_vec *sample;
164 
165 		if (!divide)
166 			isl_int_set(tmp, u);
167 		else {
168 			isl_int_sub(tmp, u, l);
169 			isl_int_fdiv_q_ui(tmp, tmp, 2);
170 			isl_int_add(tmp, tmp, l);
171 		}
172 		slice = add_bounds(isl_basic_set_copy(bset), f, l, tmp);
173 		sample = isl_basic_set_sample_vec(slice);
174 		if (!sample) {
175 			isl_vec_free(sol);
176 			sol = NULL;
177 			break;
178 		}
179 		if (sample->size > 0) {
180 			isl_vec_free(sol);
181 			sol = sample;
182 			isl_seq_inner_product(f, sol->el, sol->size, opt);
183 			isl_int_sub_ui(u, *opt, 1);
184 			divide = 1;
185 		} else {
186 			isl_vec_free(sample);
187 			if (!divide)
188 				break;
189 			isl_int_add_ui(l, tmp, 1);
190 			divide = 0;
191 		}
192 	}
193 
194 	isl_int_clear(tmp);
195 
196 	return sol;
197 }
198 
199 /* Find an integer point in "bset" that minimizes f (if any).
200  * If sol_p is not NULL then the integer point is returned in *sol_p.
201  * The optimal value of f is returned in *opt.
202  *
203  * The algorithm maintains a currently best solution and an interval [l, u]
204  * of values of f for which integer solutions could potentially still be found.
205  * The initial value of the best solution so far is any solution.
206  * The initial value of l is minimal value of f over the rationals
207  * (rounded up to the nearest integer).
208  * The initial value of u is the value of f at the initial solution minus 1.
209  *
210  * We then call solve_ilp_search to perform a binary search on the interval.
211  */
solve_ilp(__isl_keep isl_basic_set * bset,isl_int * f,isl_int * opt,__isl_give isl_vec ** sol_p)212 static enum isl_lp_result solve_ilp(__isl_keep isl_basic_set *bset,
213 	isl_int *f, isl_int *opt, __isl_give isl_vec **sol_p)
214 {
215 	enum isl_lp_result res;
216 	isl_int l, u;
217 	struct isl_vec *sol;
218 
219 	res = isl_basic_set_solve_lp(bset, 0, f, bset->ctx->one,
220 					opt, NULL, &sol);
221 	if (res == isl_lp_ok && isl_int_is_one(sol->el[0])) {
222 		if (sol_p)
223 			*sol_p = sol;
224 		else
225 			isl_vec_free(sol);
226 		return isl_lp_ok;
227 	}
228 	isl_vec_free(sol);
229 	if (res == isl_lp_error || res == isl_lp_empty)
230 		return res;
231 
232 	sol = initial_solution(bset, f);
233 	if (!sol)
234 		return isl_lp_error;
235 	if (sol->size == 0) {
236 		isl_vec_free(sol);
237 		return isl_lp_empty;
238 	}
239 	if (res == isl_lp_unbounded) {
240 		isl_vec_free(sol);
241 		return isl_lp_unbounded;
242 	}
243 
244 	isl_int_init(l);
245 	isl_int_init(u);
246 
247 	isl_int_set(l, *opt);
248 
249 	isl_seq_inner_product(f, sol->el, sol->size, opt);
250 	isl_int_sub_ui(u, *opt, 1);
251 
252 	sol = solve_ilp_search(bset, f, opt, sol, l, u);
253 	if (!sol)
254 		res = isl_lp_error;
255 
256 	isl_int_clear(l);
257 	isl_int_clear(u);
258 
259 	if (sol_p)
260 		*sol_p = sol;
261 	else
262 		isl_vec_free(sol);
263 
264 	return res;
265 }
266 
solve_ilp_with_eq(__isl_keep isl_basic_set * bset,int max,isl_int * f,isl_int * opt,__isl_give isl_vec ** sol_p)267 static enum isl_lp_result solve_ilp_with_eq(__isl_keep isl_basic_set *bset,
268 	int max, isl_int *f, isl_int *opt, __isl_give isl_vec **sol_p)
269 {
270 	isl_size dim;
271 	enum isl_lp_result res;
272 	struct isl_mat *T = NULL;
273 	struct isl_vec *v;
274 
275 	bset = isl_basic_set_copy(bset);
276 	dim = isl_basic_set_dim(bset, isl_dim_all);
277 	if (dim < 0)
278 		goto error;
279 	v = isl_vec_alloc(bset->ctx, 1 + dim);
280 	if (!v)
281 		goto error;
282 	isl_seq_cpy(v->el, f, 1 + dim);
283 	bset = isl_basic_set_remove_equalities(bset, &T, NULL);
284 	v = isl_vec_mat_product(v, isl_mat_copy(T));
285 	if (!v)
286 		goto error;
287 	res = isl_basic_set_solve_ilp(bset, max, v->el, opt, sol_p);
288 	isl_vec_free(v);
289 	if (res == isl_lp_ok && sol_p) {
290 		*sol_p = isl_mat_vec_product(T, *sol_p);
291 		if (!*sol_p)
292 			res = isl_lp_error;
293 	} else
294 		isl_mat_free(T);
295 	isl_basic_set_free(bset);
296 	return res;
297 error:
298 	isl_mat_free(T);
299 	isl_basic_set_free(bset);
300 	return isl_lp_error;
301 }
302 
303 /* Find an integer point in "bset" that minimizes (or maximizes if max is set)
304  * f (if any).
305  * If sol_p is not NULL then the integer point is returned in *sol_p.
306  * The optimal value of f is returned in *opt.
307  *
308  * If there is any equality among the points in "bset", then we first
309  * project it out.  Otherwise, we continue with solve_ilp above.
310  */
isl_basic_set_solve_ilp(__isl_keep isl_basic_set * bset,int max,isl_int * f,isl_int * opt,__isl_give isl_vec ** sol_p)311 enum isl_lp_result isl_basic_set_solve_ilp(__isl_keep isl_basic_set *bset,
312 	int max, isl_int *f, isl_int *opt, __isl_give isl_vec **sol_p)
313 {
314 	isl_size dim;
315 	enum isl_lp_result res;
316 
317 	if (sol_p)
318 		*sol_p = NULL;
319 
320 	if (isl_basic_set_check_no_params(bset) < 0)
321 		return isl_lp_error;
322 
323 	if (isl_basic_set_plain_is_empty(bset))
324 		return isl_lp_empty;
325 
326 	if (bset->n_eq)
327 		return solve_ilp_with_eq(bset, max, f, opt, sol_p);
328 
329 	dim = isl_basic_set_dim(bset, isl_dim_all);
330 	if (dim < 0)
331 		return isl_lp_error;
332 
333 	if (max)
334 		isl_seq_neg(f, f, 1 + dim);
335 
336 	res = solve_ilp(bset, f, opt, sol_p);
337 
338 	if (max) {
339 		isl_seq_neg(f, f, 1 + dim);
340 		isl_int_neg(*opt, *opt);
341 	}
342 
343 	return res;
344 }
345 
basic_set_opt(__isl_keep isl_basic_set * bset,int max,__isl_keep isl_aff * obj,isl_int * opt)346 static enum isl_lp_result basic_set_opt(__isl_keep isl_basic_set *bset, int max,
347 	__isl_keep isl_aff *obj, isl_int *opt)
348 {
349 	enum isl_lp_result res;
350 
351 	if (!obj)
352 		return isl_lp_error;
353 	bset = isl_basic_set_copy(bset);
354 	bset = isl_basic_set_underlying_set(bset);
355 	res = isl_basic_set_solve_ilp(bset, max, obj->v->el + 1, opt, NULL);
356 	isl_basic_set_free(bset);
357 	return res;
358 }
359 
isl_basic_set_opt(__isl_keep isl_basic_set * bset,int max,__isl_keep isl_aff * obj,isl_int * opt)360 enum isl_lp_result isl_basic_set_opt(__isl_keep isl_basic_set *bset, int max,
361 	__isl_keep isl_aff *obj, isl_int *opt)
362 {
363 	int *exp1 = NULL;
364 	int *exp2 = NULL;
365 	isl_ctx *ctx;
366 	isl_mat *bset_div = NULL;
367 	isl_mat *div = NULL;
368 	enum isl_lp_result res;
369 	isl_size bset_n_div, obj_n_div;
370 
371 	if (!bset || !obj)
372 		return isl_lp_error;
373 
374 	ctx = isl_aff_get_ctx(obj);
375 	if (!isl_space_is_equal(bset->dim, obj->ls->dim))
376 		isl_die(ctx, isl_error_invalid,
377 			"spaces don't match", return isl_lp_error);
378 	if (!isl_int_is_one(obj->v->el[0]))
379 		isl_die(ctx, isl_error_unsupported,
380 			"expecting integer affine expression",
381 			return isl_lp_error);
382 
383 	bset_n_div = isl_basic_set_dim(bset, isl_dim_div);
384 	obj_n_div = isl_aff_dim(obj, isl_dim_div);
385 	if (bset_n_div < 0 || obj_n_div < 0)
386 		return isl_lp_error;
387 	if (bset_n_div == 0 && obj_n_div == 0)
388 		return basic_set_opt(bset, max, obj, opt);
389 
390 	bset = isl_basic_set_copy(bset);
391 	obj = isl_aff_copy(obj);
392 
393 	bset_div = isl_basic_set_get_divs(bset);
394 	exp1 = isl_alloc_array(ctx, int, bset_n_div);
395 	exp2 = isl_alloc_array(ctx, int, obj_n_div);
396 	if (!bset_div || (bset_n_div && !exp1) || (obj_n_div && !exp2))
397 		goto error;
398 
399 	div = isl_merge_divs(bset_div, obj->ls->div, exp1, exp2);
400 
401 	bset = isl_basic_set_expand_divs(bset, isl_mat_copy(div), exp1);
402 	obj = isl_aff_expand_divs(obj, isl_mat_copy(div), exp2);
403 
404 	res = basic_set_opt(bset, max, obj, opt);
405 
406 	isl_mat_free(bset_div);
407 	isl_mat_free(div);
408 	free(exp1);
409 	free(exp2);
410 	isl_basic_set_free(bset);
411 	isl_aff_free(obj);
412 
413 	return res;
414 error:
415 	isl_mat_free(div);
416 	isl_mat_free(bset_div);
417 	free(exp1);
418 	free(exp2);
419 	isl_basic_set_free(bset);
420 	isl_aff_free(obj);
421 	return isl_lp_error;
422 }
423 
424 /* Compute the minimum (maximum if max is set) of the integer affine
425  * expression obj over the points in set and put the result in *opt.
426  *
427  * The parameters are assumed to have been aligned.
428  */
isl_set_opt_aligned(__isl_keep isl_set * set,int max,__isl_keep isl_aff * obj,isl_int * opt)429 static enum isl_lp_result isl_set_opt_aligned(__isl_keep isl_set *set, int max,
430 	__isl_keep isl_aff *obj, isl_int *opt)
431 {
432 	int i;
433 	enum isl_lp_result res;
434 	int empty = 1;
435 	isl_int opt_i;
436 
437 	if (!set || !obj)
438 		return isl_lp_error;
439 	if (set->n == 0)
440 		return isl_lp_empty;
441 
442 	res = isl_basic_set_opt(set->p[0], max, obj, opt);
443 	if (res == isl_lp_error || res == isl_lp_unbounded)
444 		return res;
445 	if (set->n == 1)
446 		return res;
447 	if (res == isl_lp_ok)
448 		empty = 0;
449 
450 	isl_int_init(opt_i);
451 	for (i = 1; i < set->n; ++i) {
452 		res = isl_basic_set_opt(set->p[i], max, obj, &opt_i);
453 		if (res == isl_lp_error || res == isl_lp_unbounded) {
454 			isl_int_clear(opt_i);
455 			return res;
456 		}
457 		if (res == isl_lp_empty)
458 			continue;
459 		empty = 0;
460 		if (max ? isl_int_gt(opt_i, *opt) : isl_int_lt(opt_i, *opt))
461 			isl_int_set(*opt, opt_i);
462 	}
463 	isl_int_clear(opt_i);
464 
465 	return empty ? isl_lp_empty : isl_lp_ok;
466 }
467 
468 /* Compute the minimum (maximum if max is set) of the integer affine
469  * expression obj over the points in set and put the result in *opt.
470  */
isl_set_opt(__isl_keep isl_set * set,int max,__isl_keep isl_aff * obj,isl_int * opt)471 enum isl_lp_result isl_set_opt(__isl_keep isl_set *set, int max,
472 	__isl_keep isl_aff *obj, isl_int *opt)
473 {
474 	enum isl_lp_result res;
475 	isl_bool aligned;
476 
477 	if (!set || !obj)
478 		return isl_lp_error;
479 
480 	aligned = isl_set_space_has_equal_params(set, obj->ls->dim);
481 	if (aligned < 0)
482 		return isl_lp_error;
483 	if (aligned)
484 		return isl_set_opt_aligned(set, max, obj, opt);
485 
486 	set = isl_set_copy(set);
487 	obj = isl_aff_copy(obj);
488 	set = isl_set_align_params(set, isl_aff_get_domain_space(obj));
489 	obj = isl_aff_align_params(obj, isl_set_get_space(set));
490 
491 	res = isl_set_opt_aligned(set, max, obj, opt);
492 
493 	isl_set_free(set);
494 	isl_aff_free(obj);
495 
496 	return res;
497 }
498 
499 /* Convert the result of a function that returns an isl_lp_result
500  * to an isl_val.  The numerator of "v" is set to the optimal value
501  * if lp_res is isl_lp_ok.  "max" is set if a maximum was computed.
502  *
503  * Return "v" with denominator set to 1 if lp_res is isl_lp_ok.
504  * Return NULL on error.
505  * Return a NaN if lp_res is isl_lp_empty.
506  * Return infinity or negative infinity if lp_res is isl_lp_unbounded,
507  * depending on "max".
508  */
convert_lp_result(enum isl_lp_result lp_res,__isl_take isl_val * v,int max)509 static __isl_give isl_val *convert_lp_result(enum isl_lp_result lp_res,
510 	__isl_take isl_val *v, int max)
511 {
512 	isl_ctx *ctx;
513 
514 	if (lp_res == isl_lp_ok) {
515 		isl_int_set_si(v->d, 1);
516 		return isl_val_normalize(v);
517 	}
518 	ctx = isl_val_get_ctx(v);
519 	isl_val_free(v);
520 	if (lp_res == isl_lp_error)
521 		return NULL;
522 	if (lp_res == isl_lp_empty)
523 		return isl_val_nan(ctx);
524 	if (max)
525 		return isl_val_infty(ctx);
526 	else
527 		return isl_val_neginfty(ctx);
528 }
529 
530 /* Return the minimum (maximum if max is set) of the integer affine
531  * expression "obj" over the points in "bset".
532  *
533  * Return infinity or negative infinity if the optimal value is unbounded and
534  * NaN if "bset" is empty.
535  *
536  * Call isl_basic_set_opt and translate the results.
537  */
isl_basic_set_opt_val(__isl_keep isl_basic_set * bset,int max,__isl_keep isl_aff * obj)538 __isl_give isl_val *isl_basic_set_opt_val(__isl_keep isl_basic_set *bset,
539 	int max, __isl_keep isl_aff *obj)
540 {
541 	isl_ctx *ctx;
542 	isl_val *res;
543 	enum isl_lp_result lp_res;
544 
545 	if (!bset || !obj)
546 		return NULL;
547 
548 	ctx = isl_aff_get_ctx(obj);
549 	res = isl_val_alloc(ctx);
550 	if (!res)
551 		return NULL;
552 	lp_res = isl_basic_set_opt(bset, max, obj, &res->n);
553 	return convert_lp_result(lp_res, res, max);
554 }
555 
556 /* Return the maximum of the integer affine
557  * expression "obj" over the points in "bset".
558  *
559  * Return infinity or negative infinity if the optimal value is unbounded and
560  * NaN if "bset" is empty.
561  */
isl_basic_set_max_val(__isl_keep isl_basic_set * bset,__isl_keep isl_aff * obj)562 __isl_give isl_val *isl_basic_set_max_val(__isl_keep isl_basic_set *bset,
563 	__isl_keep isl_aff *obj)
564 {
565 	return isl_basic_set_opt_val(bset, 1, obj);
566 }
567 
568 /* Return the minimum (maximum if max is set) of the integer affine
569  * expression "obj" over the points in "set".
570  *
571  * Return infinity or negative infinity if the optimal value is unbounded and
572  * NaN if "set" is empty.
573  *
574  * Call isl_set_opt and translate the results.
575  */
isl_set_opt_val(__isl_keep isl_set * set,int max,__isl_keep isl_aff * obj)576 __isl_give isl_val *isl_set_opt_val(__isl_keep isl_set *set, int max,
577 	__isl_keep isl_aff *obj)
578 {
579 	isl_ctx *ctx;
580 	isl_val *res;
581 	enum isl_lp_result lp_res;
582 
583 	if (!set || !obj)
584 		return NULL;
585 
586 	ctx = isl_aff_get_ctx(obj);
587 	res = isl_val_alloc(ctx);
588 	if (!res)
589 		return NULL;
590 	lp_res = isl_set_opt(set, max, obj, &res->n);
591 	return convert_lp_result(lp_res, res, max);
592 }
593 
594 /* Return the minimum of the integer affine
595  * expression "obj" over the points in "set".
596  *
597  * Return infinity or negative infinity if the optimal value is unbounded and
598  * NaN if "set" is empty.
599  */
isl_set_min_val(__isl_keep isl_set * set,__isl_keep isl_aff * obj)600 __isl_give isl_val *isl_set_min_val(__isl_keep isl_set *set,
601 	__isl_keep isl_aff *obj)
602 {
603 	return isl_set_opt_val(set, 0, obj);
604 }
605 
606 /* Return the maximum of the integer affine
607  * expression "obj" over the points in "set".
608  *
609  * Return infinity or negative infinity if the optimal value is unbounded and
610  * NaN if "set" is empty.
611  */
isl_set_max_val(__isl_keep isl_set * set,__isl_keep isl_aff * obj)612 __isl_give isl_val *isl_set_max_val(__isl_keep isl_set *set,
613 	__isl_keep isl_aff *obj)
614 {
615 	return isl_set_opt_val(set, 1, obj);
616 }
617 
618 /* Return the optimum (min or max depending on "max") of "v1" and "v2",
619  * where either may be NaN, signifying an uninitialized value.
620  * That is, if either is NaN, then return the other one.
621  */
val_opt(__isl_take isl_val * v1,__isl_take isl_val * v2,int max)622 static __isl_give isl_val *val_opt(__isl_take isl_val *v1,
623 	__isl_take isl_val *v2, int max)
624 {
625 	if (!v1 || !v2)
626 		goto error;
627 	if (isl_val_is_nan(v1)) {
628 		isl_val_free(v1);
629 		return v2;
630 	}
631 	if (isl_val_is_nan(v2)) {
632 		isl_val_free(v2);
633 		return v1;
634 	}
635 	if (max)
636 		return isl_val_max(v1, v2);
637 	else
638 		return isl_val_min(v1, v2);
639 error:
640 	isl_val_free(v1);
641 	isl_val_free(v2);
642 	return NULL;
643 }
644 
645 /* Internal data structure for isl_pw_aff_opt_val.
646  *
647  * "max" is set if the maximum should be computed.
648  * "res" contains the current optimum and is initialized to NaN.
649  */
650 struct isl_pw_aff_opt_data {
651 	int max;
652 
653 	isl_val *res;
654 };
655 
656 /* Update the optimum in data->res with respect to the affine function
657  * "aff" defined over "set".
658  */
piece_opt(__isl_take isl_set * set,__isl_take isl_aff * aff,void * user)659 static isl_stat piece_opt(__isl_take isl_set *set, __isl_take isl_aff *aff,
660 	void *user)
661 {
662 	struct isl_pw_aff_opt_data *data = user;
663 	isl_val *opt;
664 
665 	opt = isl_set_opt_val(set, data->max, aff);
666 	isl_set_free(set);
667 	isl_aff_free(aff);
668 
669 	data->res = val_opt(data->res, opt, data->max);
670 	if (!data->res)
671 		return isl_stat_error;
672 
673 	return isl_stat_ok;
674 }
675 
676 /* Return the minimum (maximum if "max" is set) of the integer piecewise affine
677  * expression "pa" over its definition domain.
678  *
679  * Return infinity or negative infinity if the optimal value is unbounded and
680  * NaN if the domain of "pa" is empty.
681  *
682  * Initialize the result to NaN and then update it for each of the pieces
683  * in "pa".
684  */
isl_pw_aff_opt_val(__isl_take isl_pw_aff * pa,int max)685 static __isl_give isl_val *isl_pw_aff_opt_val(__isl_take isl_pw_aff *pa,
686 	int max)
687 {
688 	struct isl_pw_aff_opt_data data = { max };
689 
690 	data.res = isl_val_nan(isl_pw_aff_get_ctx(pa));
691 	if (isl_pw_aff_foreach_piece(pa, &piece_opt, &data) < 0)
692 		data.res = isl_val_free(data.res);
693 
694 	isl_pw_aff_free(pa);
695 	return data.res;
696 }
697 
698 #undef TYPE
699 #define TYPE isl_pw_multi_aff
700 #include "isl_ilp_opt_multi_val_templ.c"
701 
702 #undef TYPE
703 #define TYPE isl_multi_pw_aff
704 #include "isl_ilp_opt_multi_val_templ.c"
705 
706 /* Internal data structure for isl_union_pw_aff_opt_val.
707  *
708  * "max" is set if the maximum should be computed.
709  * "res" contains the current optimum and is initialized to NaN.
710  */
711 struct isl_union_pw_aff_opt_data {
712 	int max;
713 
714 	isl_val *res;
715 };
716 
717 /* Update the optimum in data->res with the optimum of "pa".
718  */
pw_aff_opt(__isl_take isl_pw_aff * pa,void * user)719 static isl_stat pw_aff_opt(__isl_take isl_pw_aff *pa, void *user)
720 {
721 	struct isl_union_pw_aff_opt_data *data = user;
722 	isl_val *opt;
723 
724 	opt = isl_pw_aff_opt_val(pa, data->max);
725 
726 	data->res = val_opt(data->res, opt, data->max);
727 	if (!data->res)
728 		return isl_stat_error;
729 
730 	return isl_stat_ok;
731 }
732 
733 /* Return the minimum (maximum if "max" is set) of the integer piecewise affine
734  * expression "upa" over its definition domain.
735  *
736  * Return infinity or negative infinity if the optimal value is unbounded and
737  * NaN if the domain of the expression is empty.
738  *
739  * Initialize the result to NaN and then update it
740  * for each of the piecewise affine expressions in "upa".
741  */
isl_union_pw_aff_opt_val(__isl_take isl_union_pw_aff * upa,int max)742 static __isl_give isl_val *isl_union_pw_aff_opt_val(
743 	__isl_take isl_union_pw_aff *upa, int max)
744 {
745 	struct isl_union_pw_aff_opt_data data = { max };
746 
747 	data.res = isl_val_nan(isl_union_pw_aff_get_ctx(upa));
748 	if (isl_union_pw_aff_foreach_pw_aff(upa, &pw_aff_opt, &data) < 0)
749 		data.res = isl_val_free(data.res);
750 	isl_union_pw_aff_free(upa);
751 
752 	return data.res;
753 }
754 
755 /* Return the minimum of the integer piecewise affine
756  * expression "upa" over its definition domain.
757  *
758  * Return negative infinity if the optimal value is unbounded and
759  * NaN if the domain of the expression is empty.
760  */
isl_union_pw_aff_min_val(__isl_take isl_union_pw_aff * upa)761 __isl_give isl_val *isl_union_pw_aff_min_val(__isl_take isl_union_pw_aff *upa)
762 {
763 	return isl_union_pw_aff_opt_val(upa, 0);
764 }
765 
766 /* Return the maximum of the integer piecewise affine
767  * expression "upa" over its definition domain.
768  *
769  * Return infinity if the optimal value is unbounded and
770  * NaN if the domain of the expression is empty.
771  */
isl_union_pw_aff_max_val(__isl_take isl_union_pw_aff * upa)772 __isl_give isl_val *isl_union_pw_aff_max_val(__isl_take isl_union_pw_aff *upa)
773 {
774 	return isl_union_pw_aff_opt_val(upa, 1);
775 }
776 
777 /* Return a list of minima (maxima if "max" is set)
778  * for each of the expressions in "mupa" over their domains.
779  *
780  * An element in the list is infinity or negative infinity if the optimal
781  * value of the corresponding expression is unbounded and
782  * NaN if the domain of the expression is empty.
783  *
784  * Iterate over all the expressions in "mupa" and collect the results.
785  */
isl_multi_union_pw_aff_opt_multi_val(__isl_take isl_multi_union_pw_aff * mupa,int max)786 static __isl_give isl_multi_val *isl_multi_union_pw_aff_opt_multi_val(
787 	__isl_take isl_multi_union_pw_aff *mupa, int max)
788 {
789 	int i;
790 	isl_size n;
791 	isl_multi_val *mv;
792 
793 	n = isl_multi_union_pw_aff_size(mupa);
794 	if (n < 0)
795 		mupa = isl_multi_union_pw_aff_free(mupa);
796 	if (!mupa)
797 		return NULL;
798 
799 	mv = isl_multi_val_zero(isl_multi_union_pw_aff_get_space(mupa));
800 
801 	for (i = 0; i < n; ++i) {
802 		isl_val *v;
803 		isl_union_pw_aff *upa;
804 
805 		upa = isl_multi_union_pw_aff_get_union_pw_aff(mupa, i);
806 		v = isl_union_pw_aff_opt_val(upa, max);
807 		mv = isl_multi_val_set_val(mv, i, v);
808 	}
809 
810 	isl_multi_union_pw_aff_free(mupa);
811 	return mv;
812 }
813 
814 /* Return a list of minima (maxima if "max" is set) over the points in "uset"
815  * for each of the expressions in "obj".
816  *
817  * An element in the list is infinity or negative infinity if the optimal
818  * value of the corresponding expression is unbounded and
819  * NaN if the intersection of "uset" with the domain of the expression
820  * is empty.
821  */
isl_union_set_opt_multi_union_pw_aff(__isl_keep isl_union_set * uset,int max,__isl_keep isl_multi_union_pw_aff * obj)822 static __isl_give isl_multi_val *isl_union_set_opt_multi_union_pw_aff(
823 	__isl_keep isl_union_set *uset, int max,
824 	__isl_keep isl_multi_union_pw_aff *obj)
825 {
826 	uset = isl_union_set_copy(uset);
827 	obj = isl_multi_union_pw_aff_copy(obj);
828 	obj = isl_multi_union_pw_aff_intersect_domain(obj, uset);
829 	return isl_multi_union_pw_aff_opt_multi_val(obj, max);
830 }
831 
832 /* Return a list of minima over the points in "uset"
833  * for each of the expressions in "obj".
834  *
835  * An element in the list is infinity or negative infinity if the optimal
836  * value of the corresponding expression is unbounded and
837  * NaN if the intersection of "uset" with the domain of the expression
838  * is empty.
839  */
isl_union_set_min_multi_union_pw_aff(__isl_keep isl_union_set * uset,__isl_keep isl_multi_union_pw_aff * obj)840 __isl_give isl_multi_val *isl_union_set_min_multi_union_pw_aff(
841 	__isl_keep isl_union_set *uset, __isl_keep isl_multi_union_pw_aff *obj)
842 {
843 	return isl_union_set_opt_multi_union_pw_aff(uset, 0, obj);
844 }
845 
846 /* Return a list of minima
847  * for each of the expressions in "mupa" over their domains.
848  *
849  * An element in the list is negative infinity if the optimal
850  * value of the corresponding expression is unbounded and
851  * NaN if the domain of the expression is empty.
852  */
isl_multi_union_pw_aff_min_multi_val(__isl_take isl_multi_union_pw_aff * mupa)853 __isl_give isl_multi_val *isl_multi_union_pw_aff_min_multi_val(
854 	__isl_take isl_multi_union_pw_aff *mupa)
855 {
856 	return isl_multi_union_pw_aff_opt_multi_val(mupa, 0);
857 }
858 
859 /* Return a list of maxima
860  * for each of the expressions in "mupa" over their domains.
861  *
862  * An element in the list is infinity if the optimal
863  * value of the corresponding expression is unbounded and
864  * NaN if the domain of the expression is empty.
865  */
isl_multi_union_pw_aff_max_multi_val(__isl_take isl_multi_union_pw_aff * mupa)866 __isl_give isl_multi_val *isl_multi_union_pw_aff_max_multi_val(
867 	__isl_take isl_multi_union_pw_aff *mupa)
868 {
869 	return isl_multi_union_pw_aff_opt_multi_val(mupa, 1);
870 }
871 
872 #undef BASE
873 #define BASE	basic_set
874 #include "isl_ilp_opt_val_templ.c"
875 
876 /* Return the maximal value attained by the given set dimension,
877  * independently of the parameter values and of any other dimensions.
878  *
879  * Return infinity if the optimal value is unbounded and
880  * NaN if "bset" is empty.
881  */
isl_basic_set_dim_max_val(__isl_take isl_basic_set * bset,int pos)882 __isl_give isl_val *isl_basic_set_dim_max_val(__isl_take isl_basic_set *bset,
883 	int pos)
884 {
885 	return isl_basic_set_dim_opt_val(bset, 1, pos);
886 }
887 
888 #undef BASE
889 #define BASE	set
890 #include "isl_ilp_opt_val_templ.c"
891 
892 /* Return the minimal value attained by the given set dimension,
893  * independently of the parameter values and of any other dimensions.
894  *
895  * Return negative infinity if the optimal value is unbounded and
896  * NaN if "set" is empty.
897  */
isl_set_dim_min_val(__isl_take isl_set * set,int pos)898 __isl_give isl_val *isl_set_dim_min_val(__isl_take isl_set *set, int pos)
899 {
900 	return isl_set_dim_opt_val(set, 0, pos);
901 }
902 
903 /* Return the maximal value attained by the given set dimension,
904  * independently of the parameter values and of any other dimensions.
905  *
906  * Return infinity if the optimal value is unbounded and
907  * NaN if "set" is empty.
908  */
isl_set_dim_max_val(__isl_take isl_set * set,int pos)909 __isl_give isl_val *isl_set_dim_max_val(__isl_take isl_set *set, int pos)
910 {
911 	return isl_set_dim_opt_val(set, 1, pos);
912 }
913