isl_union_set_intersect: special case intersection with parameter domain
[platform/upstream/isl.git] / isl_pw_templ.c
1 #define xFN(TYPE,NAME) TYPE ## _ ## NAME
2 #define FN(TYPE,NAME) xFN(TYPE,NAME)
3 #define xS(TYPE,NAME) struct TYPE ## _ ## NAME
4 #define S(TYPE,NAME) xS(TYPE,NAME)
5
6 #ifdef HAS_TYPE
7 __isl_give PW *FN(PW,alloc_size)(__isl_take isl_space *dim,
8         enum isl_fold type, int n)
9 #else
10 __isl_give PW *FN(PW,alloc_size)(__isl_take isl_space *dim, int n)
11 #endif
12 {
13         isl_ctx *ctx;
14         struct PW *pw;
15
16         if (!dim)
17                 return NULL;
18         ctx = isl_space_get_ctx(dim);
19         isl_assert(ctx, n >= 0, goto error);
20         pw = isl_alloc(ctx, struct PW,
21                         sizeof(struct PW) + (n - 1) * sizeof(S(PW,piece)));
22         if (!pw)
23                 goto error;
24
25         pw->ref = 1;
26 #ifdef HAS_TYPE
27         pw->type = type;
28 #endif
29         pw->size = n;
30         pw->n = 0;
31         pw->dim = dim;
32         return pw;
33 error:
34         isl_space_free(dim);
35         return NULL;
36 }
37
38 #ifdef HAS_TYPE
39 __isl_give PW *FN(PW,ZERO)(__isl_take isl_space *dim, enum isl_fold type)
40 {
41         return FN(PW,alloc_size)(dim, type, 0);
42 }
43 #else
44 __isl_give PW *FN(PW,ZERO)(__isl_take isl_space *dim)
45 {
46         return FN(PW,alloc_size)(dim, 0);
47 }
48 #endif
49
50 __isl_give PW *FN(PW,add_piece)(__isl_take PW *pw,
51         __isl_take isl_set *set, __isl_take EL *el)
52 {
53         isl_ctx *ctx;
54         isl_space *el_dim = NULL;
55
56         if (!pw || !set || !el)
57                 goto error;
58
59         if (isl_set_plain_is_empty(set) || FN(EL,EL_IS_ZERO)(el)) {
60                 isl_set_free(set);
61                 FN(EL,free)(el);
62                 return pw;
63         }
64
65         ctx = isl_set_get_ctx(set);
66 #ifdef HAS_TYPE
67         if (pw->type != el->type)
68                 isl_die(ctx, isl_error_invalid, "fold types don't match",
69                         goto error);
70 #endif
71         el_dim = FN(EL,get_space(el));
72         isl_assert(ctx, isl_space_is_equal(pw->dim, el_dim), goto error);
73         isl_assert(ctx, pw->n < pw->size, goto error);
74
75         pw->p[pw->n].set = set;
76         pw->p[pw->n].FIELD = el;
77         pw->n++;
78         
79         isl_space_free(el_dim);
80         return pw;
81 error:
82         isl_space_free(el_dim);
83         FN(PW,free)(pw);
84         isl_set_free(set);
85         FN(EL,free)(el);
86         return NULL;
87 }
88
89 #ifdef HAS_TYPE
90 __isl_give PW *FN(PW,alloc)(enum isl_fold type,
91         __isl_take isl_set *set, __isl_take EL *el)
92 #else
93 __isl_give PW *FN(PW,alloc)(__isl_take isl_set *set, __isl_take EL *el)
94 #endif
95 {
96         PW *pw;
97
98         if (!set || !el)
99                 goto error;
100
101 #ifdef HAS_TYPE
102         pw = FN(PW,alloc_size)(FN(EL,get_space)(el), type, 1);
103 #else
104         pw = FN(PW,alloc_size)(FN(EL,get_space)(el), 1);
105 #endif
106
107         return FN(PW,add_piece)(pw, set, el);
108 error:
109         isl_set_free(set);
110         FN(EL,free)(el);
111         return NULL;
112 }
113
114 __isl_give PW *FN(PW,dup)(__isl_keep PW *pw)
115 {
116         int i;
117         PW *dup;
118
119         if (!pw)
120                 return NULL;
121
122 #ifdef HAS_TYPE
123         dup = FN(PW,alloc_size)(isl_space_copy(pw->dim), pw->type, pw->n);
124 #else
125         dup = FN(PW,alloc_size)(isl_space_copy(pw->dim), pw->n);
126 #endif
127         if (!dup)
128                 return NULL;
129
130         for (i = 0; i < pw->n; ++i)
131                 dup = FN(PW,add_piece)(dup, isl_set_copy(pw->p[i].set),
132                                             FN(EL,copy)(pw->p[i].FIELD));
133
134         return dup;
135 }
136
137 __isl_give PW *FN(PW,cow)(__isl_take PW *pw)
138 {
139         if (!pw)
140                 return NULL;
141
142         if (pw->ref == 1)
143                 return pw;
144         pw->ref--;
145         return FN(PW,dup)(pw);
146 }
147
148 __isl_give PW *FN(PW,copy)(__isl_keep PW *pw)
149 {
150         if (!pw)
151                 return NULL;
152
153         pw->ref++;
154         return pw;
155 }
156
157 void *FN(PW,free)(__isl_take PW *pw)
158 {
159         int i;
160
161         if (!pw)
162                 return NULL;
163         if (--pw->ref > 0)
164                 return NULL;
165
166         for (i = 0; i < pw->n; ++i) {
167                 isl_set_free(pw->p[i].set);
168                 FN(EL,free)(pw->p[i].FIELD);
169         }
170         isl_space_free(pw->dim);
171         free(pw);
172
173         return NULL;
174 }
175
176 const char *FN(PW,get_dim_name)(__isl_keep PW *pw, enum isl_dim_type type,
177         unsigned pos)
178 {
179         return pw ? isl_space_get_dim_name(pw->dim, type, pos) : NULL;
180 }
181
182 __isl_give isl_id *FN(PW,get_dim_id)(__isl_keep PW *pw, enum isl_dim_type type,
183         unsigned pos)
184 {
185         return pw ? isl_space_get_dim_id(pw->dim, type, pos) : NULL;
186 }
187
188 const char *FN(PW,get_tuple_name)(__isl_keep PW *pw, enum isl_dim_type type)
189 {
190         return pw ? isl_space_get_tuple_name(pw->dim, type) : NULL;
191 }
192
193 int FN(PW,has_tuple_id)(__isl_keep PW *pw, enum isl_dim_type type)
194 {
195         return pw ? isl_space_has_tuple_id(pw->dim, type) : -1;
196 }
197
198 __isl_give isl_id *FN(PW,get_tuple_id)(__isl_keep PW *pw, enum isl_dim_type type)
199 {
200         return pw ? isl_space_get_tuple_id(pw->dim, type) : NULL;
201 }
202
203 int FN(PW,IS_ZERO)(__isl_keep PW *pw)
204 {
205         if (!pw)
206                 return -1;
207
208         return pw->n == 0;
209 }
210
211 #ifndef NO_REALIGN
212 __isl_give PW *FN(PW,realign_domain)(__isl_take PW *pw,
213         __isl_take isl_reordering *exp)
214 {
215         int i;
216
217         pw = FN(PW,cow)(pw);
218         if (!pw || !exp)
219                 return NULL;
220
221         for (i = 0; i < pw->n; ++i) {
222                 pw->p[i].set = isl_set_realign(pw->p[i].set,
223                                                     isl_reordering_copy(exp));
224                 if (!pw->p[i].set)
225                         goto error;
226                 pw->p[i].FIELD = FN(EL,realign_domain)(pw->p[i].FIELD,
227                                                     isl_reordering_copy(exp));
228                 if (!pw->p[i].FIELD)
229                         goto error;
230         }
231
232         pw = FN(PW,reset_domain_space)(pw, isl_space_copy(exp->dim));
233
234         isl_reordering_free(exp);
235         return pw;
236 error:
237         isl_reordering_free(exp);
238         FN(PW,free)(pw);
239         return NULL;
240 }
241
242 /* Align the parameters of "pw" to those of "model".
243  */
244 __isl_give PW *FN(PW,align_params)(__isl_take PW *pw, __isl_take isl_space *model)
245 {
246         isl_ctx *ctx;
247
248         if (!pw || !model)
249                 goto error;
250
251         ctx = isl_space_get_ctx(model);
252         if (!isl_space_has_named_params(model))
253                 isl_die(ctx, isl_error_invalid,
254                         "model has unnamed parameters", goto error);
255         if (!isl_space_has_named_params(pw->dim))
256                 isl_die(ctx, isl_error_invalid,
257                         "input has unnamed parameters", goto error);
258         if (!isl_space_match(pw->dim, isl_dim_param, model, isl_dim_param)) {
259                 isl_reordering *exp;
260
261                 model = isl_space_drop_dims(model, isl_dim_in,
262                                         0, isl_space_dim(model, isl_dim_in));
263                 model = isl_space_drop_dims(model, isl_dim_out,
264                                         0, isl_space_dim(model, isl_dim_out));
265                 exp = isl_parameter_alignment_reordering(pw->dim, model);
266                 exp = isl_reordering_extend_space(exp,
267                                         FN(PW,get_domain_space)(pw));
268                 pw = FN(PW,realign_domain)(pw, exp);
269         }
270
271         isl_space_free(model);
272         return pw;
273 error:
274         isl_space_free(model);
275         FN(PW,free)(pw);
276         return NULL;
277 }
278
279 static __isl_give PW *FN(PW,align_params_pw_pw_and)(__isl_take PW *pw1,
280         __isl_take PW *pw2,
281         __isl_give PW *(*fn)(__isl_take PW *pw1, __isl_take PW *pw2))
282 {
283         isl_ctx *ctx;
284
285         if (!pw1 || !pw2)
286                 goto error;
287         if (isl_space_match(pw1->dim, isl_dim_param, pw2->dim, isl_dim_param))
288                 return fn(pw1, pw2);
289         ctx = FN(PW,get_ctx)(pw1);
290         if (!isl_space_has_named_params(pw1->dim) ||
291             !isl_space_has_named_params(pw2->dim))
292                 isl_die(ctx, isl_error_invalid,
293                         "unaligned unnamed parameters", goto error);
294         pw1 = FN(PW,align_params)(pw1, FN(PW,get_space)(pw2));
295         pw2 = FN(PW,align_params)(pw2, FN(PW,get_space)(pw1));
296         return fn(pw1, pw2);
297 error:
298         FN(PW,free)(pw1);
299         FN(PW,free)(pw2);
300         return NULL;
301 }
302
303 static __isl_give PW *FN(PW,align_params_pw_set_and)(__isl_take PW *pw,
304         __isl_take isl_set *set,
305         __isl_give PW *(*fn)(__isl_take PW *pw, __isl_take isl_set *set))
306 {
307         isl_ctx *ctx;
308
309         if (!pw || !set)
310                 goto error;
311         if (isl_space_match(pw->dim, isl_dim_param, set->dim, isl_dim_param))
312                 return fn(pw, set);
313         ctx = FN(PW,get_ctx)(pw);
314         if (!isl_space_has_named_params(pw->dim) ||
315             !isl_space_has_named_params(set->dim))
316                 isl_die(ctx, isl_error_invalid,
317                         "unaligned unnamed parameters", goto error);
318         pw = FN(PW,align_params)(pw, isl_set_get_space(set));
319         set = isl_set_align_params(set, FN(PW,get_space)(pw));
320         return fn(pw, set);
321 error:
322         FN(PW,free)(pw);
323         isl_set_free(set);
324         return NULL;
325 }
326 #endif
327
328 static __isl_give PW *FN(PW,union_add_aligned)(__isl_take PW *pw1,
329         __isl_take PW *pw2)
330 {
331         int i, j, n;
332         struct PW *res;
333         isl_ctx *ctx;
334         isl_set *set;
335
336         if (!pw1 || !pw2)
337                 goto error;
338
339         ctx = isl_space_get_ctx(pw1->dim);
340 #ifdef HAS_TYPE
341         if (pw1->type != pw2->type)
342                 isl_die(ctx, isl_error_invalid,
343                         "fold types don't match", goto error);
344 #endif
345         isl_assert(ctx, isl_space_is_equal(pw1->dim, pw2->dim), goto error);
346
347         if (FN(PW,IS_ZERO)(pw1)) {
348                 FN(PW,free)(pw1);
349                 return pw2;
350         }
351
352         if (FN(PW,IS_ZERO)(pw2)) {
353                 FN(PW,free)(pw2);
354                 return pw1;
355         }
356
357         n = (pw1->n + 1) * (pw2->n + 1);
358 #ifdef HAS_TYPE
359         res = FN(PW,alloc_size)(isl_space_copy(pw1->dim), pw1->type, n);
360 #else
361         res = FN(PW,alloc_size)(isl_space_copy(pw1->dim), n);
362 #endif
363
364         for (i = 0; i < pw1->n; ++i) {
365                 set = isl_set_copy(pw1->p[i].set);
366                 for (j = 0; j < pw2->n; ++j) {
367                         struct isl_set *common;
368                         EL *sum;
369                         set = isl_set_subtract(set,
370                                         isl_set_copy(pw2->p[j].set));
371                         common = isl_set_intersect(isl_set_copy(pw1->p[i].set),
372                                                 isl_set_copy(pw2->p[j].set));
373                         if (isl_set_plain_is_empty(common)) {
374                                 isl_set_free(common);
375                                 continue;
376                         }
377
378                         sum = FN(EL,add_on_domain)(common,
379                                                    FN(EL,copy)(pw1->p[i].FIELD),
380                                                    FN(EL,copy)(pw2->p[j].FIELD));
381
382                         res = FN(PW,add_piece)(res, common, sum);
383                 }
384                 res = FN(PW,add_piece)(res, set, FN(EL,copy)(pw1->p[i].FIELD));
385         }
386
387         for (j = 0; j < pw2->n; ++j) {
388                 set = isl_set_copy(pw2->p[j].set);
389                 for (i = 0; i < pw1->n; ++i)
390                         set = isl_set_subtract(set,
391                                         isl_set_copy(pw1->p[i].set));
392                 res = FN(PW,add_piece)(res, set, FN(EL,copy)(pw2->p[j].FIELD));
393         }
394
395         FN(PW,free)(pw1);
396         FN(PW,free)(pw2);
397
398         return res;
399 error:
400         FN(PW,free)(pw1);
401         FN(PW,free)(pw2);
402         return NULL;
403 }
404
405 /* Private version of "union_add".  For isl_pw_qpolynomial and
406  * isl_pw_qpolynomial_fold, we prefer to simply call it "add".
407  */
408 static __isl_give PW *FN(PW,union_add_)(__isl_take PW *pw1, __isl_take PW *pw2)
409 {
410         return FN(PW,align_params_pw_pw_and)(pw1, pw2,
411                                                 &FN(PW,union_add_aligned));
412 }
413
414 /* Make sure "pw" has room for at least "n" more pieces.
415  *
416  * If there is only one reference to pw, we extend it in place.
417  * Otherwise, we create a new PW and copy the pieces.
418  */
419 static __isl_give PW *FN(PW,grow)(__isl_take PW *pw, int n)
420 {
421         int i;
422         isl_ctx *ctx;
423         PW *res;
424
425         if (!pw)
426                 return NULL;
427         if (pw->n + n <= pw->size)
428                 return pw;
429         ctx = FN(PW,get_ctx)(pw);
430         n += pw->n;
431         if (pw->ref == 1) {
432                 res = isl_realloc(ctx, pw, struct PW,
433                             sizeof(struct PW) + (n - 1) * sizeof(S(PW,piece)));
434                 if (!res)
435                         return FN(PW,free)(pw);
436                 res->size = n;
437                 return res;
438         }
439 #ifdef HAS_TYPE
440         res = FN(PW,alloc_size)(isl_space_copy(pw->dim), pw->type, n);
441 #else
442         res = FN(PW,alloc_size)(isl_space_copy(pw->dim), n);
443 #endif
444         if (!res)
445                 return FN(PW,free)(pw);
446         for (i = 0; i < pw->n; ++i)
447                 res = FN(PW,add_piece)(res, isl_set_copy(pw->p[i].set),
448                                             FN(EL,copy)(pw->p[i].FIELD));
449         FN(PW,free)(pw);
450         return res;
451 }
452
453 static __isl_give PW *FN(PW,add_disjoint_aligned)(__isl_take PW *pw1,
454         __isl_take PW *pw2)
455 {
456         int i;
457         isl_ctx *ctx;
458
459         if (!pw1 || !pw2)
460                 goto error;
461
462         if (pw1->size < pw1->n + pw2->n && pw1->n < pw2->n)
463                 return FN(PW,add_disjoint_aligned)(pw2, pw1);
464
465         ctx = isl_space_get_ctx(pw1->dim);
466 #ifdef HAS_TYPE
467         if (pw1->type != pw2->type)
468                 isl_die(ctx, isl_error_invalid,
469                         "fold types don't match", goto error);
470 #endif
471         isl_assert(ctx, isl_space_is_equal(pw1->dim, pw2->dim), goto error);
472
473         if (FN(PW,IS_ZERO)(pw1)) {
474                 FN(PW,free)(pw1);
475                 return pw2;
476         }
477
478         if (FN(PW,IS_ZERO)(pw2)) {
479                 FN(PW,free)(pw2);
480                 return pw1;
481         }
482
483         pw1 = FN(PW,grow)(pw1, pw2->n);
484         if (!pw1)
485                 goto error;
486
487         for (i = 0; i < pw2->n; ++i)
488                 pw1 = FN(PW,add_piece)(pw1,
489                                 isl_set_copy(pw2->p[i].set),
490                                 FN(EL,copy)(pw2->p[i].FIELD));
491
492         FN(PW,free)(pw2);
493
494         return pw1;
495 error:
496         FN(PW,free)(pw1);
497         FN(PW,free)(pw2);
498         return NULL;
499 }
500
501 __isl_give PW *FN(PW,add_disjoint)(__isl_take PW *pw1, __isl_take PW *pw2)
502 {
503         return FN(PW,align_params_pw_pw_and)(pw1, pw2,
504                                                 &FN(PW,add_disjoint_aligned));
505 }
506
507 /* This function is currently only used from isl_aff.c
508  */
509 static __isl_give PW *FN(PW,on_shared_domain)(__isl_take PW *pw1,
510         __isl_take PW *pw2,
511         __isl_give EL *(*fn)(__isl_take EL *el1, __isl_take EL *el2))
512         __attribute__ ((unused));
513
514 /* Apply "fn" to pairs of elements from pw1 and pw2 on shared domains.
515  */
516 static __isl_give PW *FN(PW,on_shared_domain)(__isl_take PW *pw1,
517         __isl_take PW *pw2,
518         __isl_give EL *(*fn)(__isl_take EL *el1, __isl_take EL *el2))
519 {
520         int i, j, n;
521         PW *res;
522
523         if (!pw1 || !pw2)
524                 goto error;
525
526         n = pw1->n * pw2->n;
527 #ifdef HAS_TYPE
528         res = FN(PW,alloc_size)(isl_space_copy(pw1->dim), pw1->type, n);
529 #else
530         res = FN(PW,alloc_size)(isl_space_copy(pw1->dim), n);
531 #endif
532
533         for (i = 0; i < pw1->n; ++i) {
534                 for (j = 0; j < pw2->n; ++j) {
535                         isl_set *common;
536                         EL *res_ij;
537                         common = isl_set_intersect(
538                                         isl_set_copy(pw1->p[i].set),
539                                         isl_set_copy(pw2->p[j].set));
540                         if (isl_set_plain_is_empty(common)) {
541                                 isl_set_free(common);
542                                 continue;
543                         }
544
545                         res_ij = fn(FN(EL,copy)(pw1->p[i].FIELD),
546                                     FN(EL,copy)(pw2->p[j].FIELD));
547
548                         res = FN(PW,add_piece)(res, common, res_ij);
549                 }
550         }
551
552         FN(PW,free)(pw1);
553         FN(PW,free)(pw2);
554         return res;
555 error:
556         FN(PW,free)(pw1);
557         FN(PW,free)(pw2);
558         return NULL;
559 }
560
561 #ifndef NO_NEG
562 __isl_give PW *FN(PW,neg)(__isl_take PW *pw)
563 {
564         int i;
565
566         if (!pw)
567                 return NULL;
568
569         if (FN(PW,IS_ZERO)(pw))
570                 return pw;
571
572         pw = FN(PW,cow)(pw);
573         if (!pw)
574                 return NULL;
575
576         for (i = 0; i < pw->n; ++i) {
577                 pw->p[i].FIELD = FN(EL,neg)(pw->p[i].FIELD);
578                 if (!pw->p[i].FIELD)
579                         return FN(PW,free)(pw);
580         }
581
582         return pw;
583 }
584
585 __isl_give PW *FN(PW,sub)(__isl_take PW *pw1, __isl_take PW *pw2)
586 {
587         return FN(PW,add)(pw1, FN(PW,neg)(pw2));
588 }
589 #endif
590
591 #ifndef NO_EVAL
592 __isl_give isl_qpolynomial *FN(PW,eval)(__isl_take PW *pw,
593         __isl_take isl_point *pnt)
594 {
595         int i;
596         int found = 0;
597         isl_ctx *ctx;
598         isl_space *pnt_dim = NULL;
599         isl_qpolynomial *qp;
600
601         if (!pw || !pnt)
602                 goto error;
603         ctx = isl_point_get_ctx(pnt);
604         pnt_dim = isl_point_get_space(pnt);
605         isl_assert(ctx, isl_space_is_domain(pnt_dim, pw->dim), goto error);
606
607         for (i = 0; i < pw->n; ++i) {
608                 found = isl_set_contains_point(pw->p[i].set, pnt);
609                 if (found < 0)
610                         goto error;
611                 if (found)
612                         break;
613         }
614         if (found)
615                 qp = FN(EL,eval)(FN(EL,copy)(pw->p[i].FIELD),
616                                             isl_point_copy(pnt));
617         else
618                 qp = isl_qpolynomial_zero_on_domain(FN(PW,get_domain_space)(pw));
619         FN(PW,free)(pw);
620         isl_space_free(pnt_dim);
621         isl_point_free(pnt);
622         return qp;
623 error:
624         FN(PW,free)(pw);
625         isl_space_free(pnt_dim);
626         isl_point_free(pnt);
627         return NULL;
628 }
629 #endif
630
631 __isl_give isl_set *FN(PW,domain)(__isl_take PW *pw)
632 {
633         int i;
634         isl_set *dom;
635
636         if (!pw)
637                 return NULL;
638
639         dom = isl_set_empty(FN(PW,get_domain_space)(pw));
640         for (i = 0; i < pw->n; ++i)
641                 dom = isl_set_union_disjoint(dom, isl_set_copy(pw->p[i].set));
642
643         FN(PW,free)(pw);
644
645         return dom;
646 }
647
648 static __isl_give PW *FN(PW,intersect_domain_aligned)(__isl_take PW *pw,
649         __isl_take isl_set *set)
650 {
651         int i;
652
653         if (!pw || !set)
654                 goto error;
655
656         if (pw->n == 0) {
657                 isl_set_free(set);
658                 return pw;
659         }
660
661         pw = FN(PW,cow)(pw);
662         if (!pw)
663                 goto error;
664
665         for (i = pw->n - 1; i >= 0; --i) {
666                 isl_basic_set *aff;
667                 pw->p[i].set = isl_set_intersect(pw->p[i].set, isl_set_copy(set));
668                 if (!pw->p[i].set)
669                         goto error;
670                 aff = isl_set_affine_hull(isl_set_copy(pw->p[i].set));
671                 pw->p[i].FIELD = FN(EL,substitute_equalities)(pw->p[i].FIELD,
672                                                                 aff);
673                 if (!pw->p[i].FIELD)
674                         goto error;
675                 if (isl_set_plain_is_empty(pw->p[i].set)) {
676                         isl_set_free(pw->p[i].set);
677                         FN(EL,free)(pw->p[i].FIELD);
678                         if (i != pw->n - 1)
679                                 pw->p[i] = pw->p[pw->n - 1];
680                         pw->n--;
681                 }
682         }
683         
684         isl_set_free(set);
685         return pw;
686 error:
687         isl_set_free(set);
688         FN(PW,free)(pw);
689         return NULL;
690 }
691
692 __isl_give PW *FN(PW,intersect_domain)(__isl_take PW *pw,
693         __isl_take isl_set *context)
694 {
695         return FN(PW,align_params_pw_set_and)(pw, context,
696                                         &FN(PW,intersect_domain_aligned));
697 }
698
699 static __isl_give PW *FN(PW,gist_aligned)(__isl_take PW *pw,
700         __isl_take isl_set *context)
701 {
702         int i;
703         isl_basic_set *hull = NULL;
704
705         if (!pw || !context)
706                 goto error;
707
708         if (pw->n == 0) {
709                 isl_set_free(context);
710                 return pw;
711         }
712
713         if (!isl_space_match(pw->dim, isl_dim_param,
714                                 context->dim, isl_dim_param)) {
715                 pw = FN(PW,align_params)(pw, isl_set_get_space(context));
716                 context = isl_set_align_params(context, FN(PW,get_space)(pw));
717         }
718
719         context = isl_set_compute_divs(context);
720         hull = isl_set_simple_hull(isl_set_copy(context));
721
722         pw = FN(PW,cow)(pw);
723         if (!pw)
724                 goto error;
725
726         for (i = pw->n - 1; i >= 0; --i) {
727                 pw->p[i].set = isl_set_intersect(pw->p[i].set,
728                                                  isl_set_copy(context));
729                 if (!pw->p[i].set)
730                         goto error;
731                 pw->p[i].FIELD = FN(EL,gist)(pw->p[i].FIELD,
732                                              isl_set_copy(pw->p[i].set));
733                 pw->p[i].set = isl_set_gist_basic_set(pw->p[i].set,
734                                                 isl_basic_set_copy(hull));
735                 if (!pw->p[i].set)
736                         goto error;
737                 if (isl_set_plain_is_empty(pw->p[i].set)) {
738                         isl_set_free(pw->p[i].set);
739                         FN(EL,free)(pw->p[i].FIELD);
740                         if (i != pw->n - 1)
741                                 pw->p[i] = pw->p[pw->n - 1];
742                         pw->n--;
743                 }
744         }
745
746         isl_basic_set_free(hull);
747         isl_set_free(context);
748
749         return pw;
750 error:
751         FN(PW,free)(pw);
752         isl_basic_set_free(hull);
753         isl_set_free(context);
754         return NULL;
755 }
756
757 __isl_give PW *FN(PW,gist)(__isl_take PW *pw, __isl_take isl_set *context)
758 {
759         return FN(PW,align_params_pw_set_and)(pw, context, &FN(PW,gist_aligned));
760 }
761
762 __isl_give PW *FN(PW,coalesce)(__isl_take PW *pw)
763 {
764         int i, j;
765
766         if (!pw)
767                 return NULL;
768         if (pw->n == 0)
769                 return pw;
770
771         for (i = pw->n - 1; i >= 0; --i) {
772                 for (j = i - 1; j >= 0; --j) {
773                         if (!FN(EL,plain_is_equal)(pw->p[i].FIELD,
774                                                         pw->p[j].FIELD))
775                                 continue;
776                         pw->p[j].set = isl_set_union(pw->p[j].set,
777                                                         pw->p[i].set);
778                         FN(EL,free)(pw->p[i].FIELD);
779                         if (i != pw->n - 1)
780                                 pw->p[i] = pw->p[pw->n - 1];
781                         pw->n--;
782                         break;
783                 }
784                 if (j >= 0)
785                         continue;
786                 pw->p[i].set = isl_set_coalesce(pw->p[i].set);
787                 if (!pw->p[i].set)
788                         goto error;
789         }
790
791         return pw;
792 error:
793         FN(PW,free)(pw);
794         return NULL;
795 }
796
797 isl_ctx *FN(PW,get_ctx)(__isl_keep PW *pw)
798 {
799         return pw ? isl_space_get_ctx(pw->dim) : NULL;
800 }
801
802 #ifndef NO_INVOLVES_DIMS
803 int FN(PW,involves_dims)(__isl_keep PW *pw, enum isl_dim_type type,
804         unsigned first, unsigned n)
805 {
806         int i;
807         enum isl_dim_type set_type;
808
809         if (!pw)
810                 return -1;
811         if (pw->n == 0 || n == 0)
812                 return 0;
813
814         set_type = type == isl_dim_in ? isl_dim_set : type;
815
816         for (i = 0; i < pw->n; ++i) {
817                 int involves = FN(EL,involves_dims)(pw->p[i].FIELD,
818                                                         type, first, n);
819                 if (involves < 0 || involves)
820                         return involves;
821                 involves = isl_set_involves_dims(pw->p[i].set,
822                                                         set_type, first, n);
823                 if (involves < 0 || involves)
824                         return involves;
825         }
826         return 0;
827 }
828 #endif
829
830 __isl_give PW *FN(PW,set_dim_name)(__isl_take PW *pw,
831         enum isl_dim_type type, unsigned pos, const char *s)
832 {
833         int i;
834         enum isl_dim_type set_type;
835
836         pw = FN(PW,cow)(pw);
837         if (!pw)
838                 return NULL;
839
840         set_type = type == isl_dim_in ? isl_dim_set : type;
841
842         pw->dim = isl_space_set_dim_name(pw->dim, type, pos, s);
843         if (!pw->dim)
844                 goto error;
845
846         for (i = 0; i < pw->n; ++i) {
847                 pw->p[i].set = isl_set_set_dim_name(pw->p[i].set,
848                                                         set_type, pos, s);
849                 if (!pw->p[i].set)
850                         goto error;
851                 pw->p[i].FIELD = FN(EL,set_dim_name)(pw->p[i].FIELD, type, pos, s);
852                 if (!pw->p[i].FIELD)
853                         goto error;
854         }
855
856         return pw;
857 error:
858         FN(PW,free)(pw);
859         return NULL;
860 }
861
862 #ifndef NO_DROP_DIMS
863 __isl_give PW *FN(PW,drop_dims)(__isl_take PW *pw,
864         enum isl_dim_type type, unsigned first, unsigned n)
865 {
866         int i;
867         enum isl_dim_type set_type;
868
869         if (!pw)
870                 return NULL;
871         if (n == 0 && !isl_space_get_tuple_name(pw->dim, type))
872                 return pw;
873
874         set_type = type == isl_dim_in ? isl_dim_set : type;
875
876         pw = FN(PW,cow)(pw);
877         if (!pw)
878                 return NULL;
879         pw->dim = isl_space_drop_dims(pw->dim, type, first, n);
880         if (!pw->dim)
881                 goto error;
882         for (i = 0; i < pw->n; ++i) {
883                 pw->p[i].set = isl_set_drop(pw->p[i].set, set_type, first, n);
884                 if (!pw->p[i].set)
885                         goto error;
886                 pw->p[i].FIELD = FN(EL,drop_dims)(pw->p[i].FIELD, type, first, n);
887                 if (!pw->p[i].FIELD)
888                         goto error;
889         }
890
891         return pw;
892 error:
893         FN(PW,free)(pw);
894         return NULL;
895 }
896
897 /* This function is very similar to drop_dims.
898  * The only difference is that the cells may still involve
899  * the specified dimensions.  They are removed using
900  * isl_set_project_out instead of isl_set_drop.
901  */
902 __isl_give PW *FN(PW,project_out)(__isl_take PW *pw,
903         enum isl_dim_type type, unsigned first, unsigned n)
904 {
905         int i;
906         enum isl_dim_type set_type;
907
908         if (!pw)
909                 return NULL;
910         if (n == 0 && !isl_space_get_tuple_name(pw->dim, type))
911                 return pw;
912
913         set_type = type == isl_dim_in ? isl_dim_set : type;
914
915         pw = FN(PW,cow)(pw);
916         if (!pw)
917                 return NULL;
918         pw->dim = isl_space_drop_dims(pw->dim, type, first, n);
919         if (!pw->dim)
920                 goto error;
921         for (i = 0; i < pw->n; ++i) {
922                 pw->p[i].set = isl_set_project_out(pw->p[i].set,
923                                                         set_type, first, n);
924                 if (!pw->p[i].set)
925                         goto error;
926                 pw->p[i].FIELD = FN(EL,drop_dims)(pw->p[i].FIELD, type, first, n);
927                 if (!pw->p[i].FIELD)
928                         goto error;
929         }
930
931         return pw;
932 error:
933         FN(PW,free)(pw);
934         return NULL;
935 }
936
937 /* Project the domain of pw onto its parameter space.
938  */
939 __isl_give PW *FN(PW,project_domain_on_params)(__isl_take PW *pw)
940 {
941         isl_space *space;
942         unsigned n;
943
944         n = FN(PW,dim)(pw, isl_dim_in);
945         pw = FN(PW,project_out)(pw, isl_dim_in, 0, n);
946         space = FN(PW,get_domain_space)(pw);
947         space = isl_space_params(space);
948         pw = FN(PW,reset_domain_space)(pw, space);
949         return pw;
950 }
951 #endif
952
953 #ifndef NO_INSERT_DIMS
954 __isl_give PW *FN(PW,insert_dims)(__isl_take PW *pw, enum isl_dim_type type,
955         unsigned first, unsigned n)
956 {
957         int i;
958         enum isl_dim_type set_type;
959
960         if (!pw)
961                 return NULL;
962         if (n == 0 && !isl_space_is_named_or_nested(pw->dim, type))
963                 return pw;
964
965         set_type = type == isl_dim_in ? isl_dim_set : type;
966
967         pw = FN(PW,cow)(pw);
968         if (!pw)
969                 return NULL;
970
971         pw->dim = isl_space_insert_dims(pw->dim, type, first, n);
972         if (!pw->dim)
973                 goto error;
974
975         for (i = 0; i < pw->n; ++i) {
976                 pw->p[i].set = isl_set_insert_dims(pw->p[i].set,
977                                                             set_type, first, n);
978                 if (!pw->p[i].set)
979                         goto error;
980                 pw->p[i].FIELD = FN(EL,insert_dims)(pw->p[i].FIELD,
981                                                                 type, first, n);
982                 if (!pw->p[i].FIELD)
983                         goto error;
984         }
985
986         return pw;
987 error:
988         FN(PW,free)(pw);
989         return NULL;
990 }
991 #endif
992
993 __isl_give PW *FN(PW,fix_dim)(__isl_take PW *pw,
994         enum isl_dim_type type, unsigned pos, isl_int v)
995 {
996         int i;
997
998         if (!pw)
999                 return NULL;
1000
1001         if (type == isl_dim_in)
1002                 type = isl_dim_set;
1003
1004         pw = FN(PW,cow)(pw);
1005         if (!pw)
1006                 return NULL;
1007         for (i = 0; i < pw->n; ++i) {
1008                 pw->p[i].set = isl_set_fix(pw->p[i].set, type, pos, v);
1009                 if (!pw->p[i].set)
1010                         goto error;
1011         }
1012
1013         return pw;
1014 error:
1015         FN(PW,free)(pw);
1016         return NULL;
1017 }
1018
1019 unsigned FN(PW,dim)(__isl_keep PW *pw, enum isl_dim_type type)
1020 {
1021         return pw ? isl_space_dim(pw->dim, type) : 0;
1022 }
1023
1024 __isl_give PW *FN(PW,split_dims)(__isl_take PW *pw,
1025         enum isl_dim_type type, unsigned first, unsigned n)
1026 {
1027         int i;
1028
1029         if (!pw)
1030                 return NULL;
1031         if (n == 0)
1032                 return pw;
1033
1034         if (type == isl_dim_in)
1035                 type = isl_dim_set;
1036
1037         pw = FN(PW,cow)(pw);
1038         if (!pw)
1039                 return NULL;
1040         if (!pw->dim)
1041                 goto error;
1042         for (i = 0; i < pw->n; ++i) {
1043                 pw->p[i].set = isl_set_split_dims(pw->p[i].set, type, first, n);
1044                 if (!pw->p[i].set)
1045                         goto error;
1046         }
1047
1048         return pw;
1049 error:
1050         FN(PW,free)(pw);
1051         return NULL;
1052 }
1053
1054 #ifndef NO_OPT
1055 /* Compute the maximal value attained by the piecewise quasipolynomial
1056  * on its domain or zero if the domain is empty.
1057  * In the worst case, the domain is scanned completely,
1058  * so the domain is assumed to be bounded.
1059  */
1060 __isl_give isl_qpolynomial *FN(PW,opt)(__isl_take PW *pw, int max)
1061 {
1062         int i;
1063         isl_qpolynomial *opt;
1064
1065         if (!pw)
1066                 return NULL;
1067
1068         if (pw->n == 0) {
1069                 isl_space *dim = isl_space_copy(pw->dim);
1070                 FN(PW,free)(pw);
1071                 return isl_qpolynomial_zero_on_domain(dim);
1072         }
1073
1074         opt = FN(EL,opt_on_domain)(FN(EL,copy)(pw->p[0].FIELD),
1075                                         isl_set_copy(pw->p[0].set), max);
1076         for (i = 1; i < pw->n; ++i) {
1077                 isl_qpolynomial *opt_i;
1078                 opt_i = FN(EL,opt_on_domain)(FN(EL,copy)(pw->p[i].FIELD),
1079                                                 isl_set_copy(pw->p[i].set), max);
1080                 if (max)
1081                         opt = isl_qpolynomial_max_cst(opt, opt_i);
1082                 else
1083                         opt = isl_qpolynomial_min_cst(opt, opt_i);
1084         }
1085
1086         FN(PW,free)(pw);
1087         return opt;
1088 }
1089
1090 __isl_give isl_qpolynomial *FN(PW,max)(__isl_take PW *pw)
1091 {
1092         return FN(PW,opt)(pw, 1);
1093 }
1094
1095 __isl_give isl_qpolynomial *FN(PW,min)(__isl_take PW *pw)
1096 {
1097         return FN(PW,opt)(pw, 0);
1098 }
1099 #endif
1100
1101 __isl_give isl_space *FN(PW,get_space)(__isl_keep PW *pw)
1102 {
1103         return pw ? isl_space_copy(pw->dim) : NULL;
1104 }
1105
1106 __isl_give isl_space *FN(PW,get_domain_space)(__isl_keep PW *pw)
1107 {
1108         return pw ? isl_space_domain(isl_space_copy(pw->dim)) : NULL;
1109 }
1110
1111 #ifndef NO_RESET_DIM
1112 /* Reset the space of "pw".  Since we don't know if the elements
1113  * represent the spaces themselves or their domains, we pass along
1114  * both when we call their reset_space_and_domain.
1115  */
1116 static __isl_give PW *FN(PW,reset_space_and_domain)(__isl_take PW *pw,
1117         __isl_take isl_space *space, __isl_take isl_space *domain)
1118 {
1119         int i;
1120
1121         pw = FN(PW,cow)(pw);
1122         if (!pw || !space || !domain)
1123                 goto error;
1124
1125         for (i = 0; i < pw->n; ++i) {
1126                 pw->p[i].set = isl_set_reset_space(pw->p[i].set,
1127                                                  isl_space_copy(domain));
1128                 if (!pw->p[i].set)
1129                         goto error;
1130                 pw->p[i].FIELD = FN(EL,reset_space_and_domain)(pw->p[i].FIELD,
1131                               isl_space_copy(space), isl_space_copy(domain));
1132                 if (!pw->p[i].FIELD)
1133                         goto error;
1134         }
1135
1136         isl_space_free(domain);
1137
1138         isl_space_free(pw->dim);
1139         pw->dim = space;
1140
1141         return pw;
1142 error:
1143         isl_space_free(domain);
1144         isl_space_free(space);
1145         FN(PW,free)(pw);
1146         return NULL;
1147 }
1148
1149 __isl_give PW *FN(PW,reset_domain_space)(__isl_take PW *pw,
1150         __isl_take isl_space *domain)
1151 {
1152         isl_space *space;
1153
1154         space = isl_space_extend_domain_with_range(isl_space_copy(domain),
1155                                                    FN(PW,get_space)(pw));
1156         return FN(PW,reset_space_and_domain)(pw, space, domain);
1157 }
1158
1159 __isl_give PW *FN(PW,reset_space)(__isl_take PW *pw, __isl_take isl_space *dim)
1160 {
1161         isl_space *domain;
1162
1163         domain = isl_space_domain(isl_space_copy(dim));
1164         return FN(PW,reset_space_and_domain)(pw, dim, domain);
1165 }
1166
1167 __isl_give PW *FN(PW,set_tuple_id)(__isl_keep PW *pw, enum isl_dim_type type,
1168         __isl_take isl_id *id)
1169 {
1170         isl_space *space;
1171
1172         pw = FN(PW,cow)(pw);
1173         if (!pw)
1174                 return isl_id_free(id);
1175
1176         space = FN(PW,get_space)(pw);
1177         space = isl_space_set_tuple_id(space, type, id);
1178
1179         return FN(PW,reset_space)(pw, space);
1180 }
1181
1182 __isl_give PW *FN(PW,set_dim_id)(__isl_take PW *pw,
1183         enum isl_dim_type type, unsigned pos, __isl_take isl_id *id)
1184 {
1185         pw = FN(PW,cow)(pw);
1186         if (!pw)
1187                 return isl_id_free(id);
1188         pw->dim = isl_space_set_dim_id(pw->dim, type, pos, id);
1189         return FN(PW,reset_space)(pw, isl_space_copy(pw->dim));
1190 }
1191 #endif
1192
1193 int FN(PW,has_equal_space)(__isl_keep PW *pw1, __isl_keep PW *pw2)
1194 {
1195         if (!pw1 || !pw2)
1196                 return -1;
1197
1198         return isl_space_is_equal(pw1->dim, pw2->dim);
1199 }
1200
1201 #ifndef NO_MORPH
1202 __isl_give PW *FN(PW,morph_domain)(__isl_take PW *pw,
1203         __isl_take isl_morph *morph)
1204 {
1205         int i;
1206         isl_ctx *ctx;
1207
1208         if (!pw || !morph)
1209                 goto error;
1210
1211         ctx = isl_space_get_ctx(pw->dim);
1212         isl_assert(ctx, isl_space_is_domain(morph->dom->dim, pw->dim),
1213                 goto error);
1214
1215         pw = FN(PW,cow)(pw);
1216         if (!pw)
1217                 goto error;
1218         pw->dim = isl_space_extend_domain_with_range(
1219                         isl_space_copy(morph->ran->dim), pw->dim);
1220         if (!pw->dim)
1221                 goto error;
1222
1223         for (i = 0; i < pw->n; ++i) {
1224                 pw->p[i].set = isl_morph_set(isl_morph_copy(morph), pw->p[i].set);
1225                 if (!pw->p[i].set)
1226                         goto error;
1227                 pw->p[i].FIELD = FN(EL,morph_domain)(pw->p[i].FIELD,
1228                                                 isl_morph_copy(morph));
1229                 if (!pw->p[i].FIELD)
1230                         goto error;
1231         }
1232
1233         isl_morph_free(morph);
1234
1235         return pw;
1236 error:
1237         FN(PW,free)(pw);
1238         isl_morph_free(morph);
1239         return NULL;
1240 }
1241 #endif
1242
1243 int FN(PW,foreach_piece)(__isl_keep PW *pw,
1244         int (*fn)(__isl_take isl_set *set, __isl_take EL *el, void *user),
1245         void *user)
1246 {
1247         int i;
1248
1249         if (!pw)
1250                 return -1;
1251
1252         for (i = 0; i < pw->n; ++i)
1253                 if (fn(isl_set_copy(pw->p[i].set),
1254                                 FN(EL,copy)(pw->p[i].FIELD), user) < 0)
1255                         return -1;
1256
1257         return 0;
1258 }
1259
1260 #ifndef NO_LIFT
1261 static int any_divs(__isl_keep isl_set *set)
1262 {
1263         int i;
1264
1265         if (!set)
1266                 return -1;
1267
1268         for (i = 0; i < set->n; ++i)
1269                 if (set->p[i]->n_div > 0)
1270                         return 1;
1271
1272         return 0;
1273 }
1274
1275 static int foreach_lifted_subset(__isl_take isl_set *set, __isl_take EL *el,
1276         int (*fn)(__isl_take isl_set *set, __isl_take EL *el,
1277                     void *user), void *user)
1278 {
1279         int i;
1280
1281         if (!set || !el)
1282                 goto error;
1283
1284         for (i = 0; i < set->n; ++i) {
1285                 isl_set *lift;
1286                 EL *copy;
1287
1288                 lift = isl_set_from_basic_set(isl_basic_set_copy(set->p[i]));
1289                 lift = isl_set_lift(lift);
1290
1291                 copy = FN(EL,copy)(el);
1292                 copy = FN(EL,lift)(copy, isl_set_get_space(lift));
1293
1294                 if (fn(lift, copy, user) < 0)
1295                         goto error;
1296         }
1297
1298         isl_set_free(set);
1299         FN(EL,free)(el);
1300
1301         return 0;
1302 error:
1303         isl_set_free(set);
1304         FN(EL,free)(el);
1305         return -1;
1306 }
1307
1308 int FN(PW,foreach_lifted_piece)(__isl_keep PW *pw,
1309         int (*fn)(__isl_take isl_set *set, __isl_take EL *el,
1310                     void *user), void *user)
1311 {
1312         int i;
1313
1314         if (!pw)
1315                 return -1;
1316
1317         for (i = 0; i < pw->n; ++i) {
1318                 isl_set *set;
1319                 EL *el;
1320
1321                 set = isl_set_copy(pw->p[i].set);
1322                 el = FN(EL,copy)(pw->p[i].FIELD);
1323                 if (!any_divs(set)) {
1324                         if (fn(set, el, user) < 0)
1325                                 return -1;
1326                         continue;
1327                 }
1328                 if (foreach_lifted_subset(set, el, fn, user) < 0)
1329                         return -1;
1330         }
1331
1332         return 0;
1333 }
1334 #endif
1335
1336 #ifndef NO_MOVE_DIMS
1337 __isl_give PW *FN(PW,move_dims)(__isl_take PW *pw,
1338         enum isl_dim_type dst_type, unsigned dst_pos,
1339         enum isl_dim_type src_type, unsigned src_pos, unsigned n)
1340 {
1341         int i;
1342
1343         pw = FN(PW,cow)(pw);
1344         if (!pw)
1345                 return NULL;
1346
1347         pw->dim = isl_space_move_dims(pw->dim, dst_type, dst_pos, src_type, src_pos, n);
1348         if (!pw->dim)
1349                 goto error;
1350
1351         for (i = 0; i < pw->n; ++i) {
1352                 pw->p[i].FIELD = FN(EL,move_dims)(pw->p[i].FIELD,
1353                                         dst_type, dst_pos, src_type, src_pos, n);
1354                 if (!pw->p[i].FIELD)
1355                         goto error;
1356         }
1357
1358         if (dst_type == isl_dim_in)
1359                 dst_type = isl_dim_set;
1360         if (src_type == isl_dim_in)
1361                 src_type = isl_dim_set;
1362
1363         for (i = 0; i < pw->n; ++i) {
1364                 pw->p[i].set = isl_set_move_dims(pw->p[i].set,
1365                                                 dst_type, dst_pos,
1366                                                 src_type, src_pos, n);
1367                 if (!pw->p[i].set)
1368                         goto error;
1369         }
1370
1371         return pw;
1372 error:
1373         FN(PW,free)(pw);
1374         return NULL;
1375 }
1376 #endif
1377
1378 __isl_give PW *FN(PW,mul_isl_int)(__isl_take PW *pw, isl_int v)
1379 {
1380         int i;
1381
1382         if (isl_int_is_one(v))
1383                 return pw;
1384         if (pw && isl_int_is_zero(v)) {
1385                 PW *zero;
1386                 isl_space *dim = FN(PW,get_space)(pw);
1387 #ifdef HAS_TYPE
1388                 zero = FN(PW,ZERO)(dim, pw->type);
1389 #else
1390                 zero = FN(PW,ZERO)(dim);
1391 #endif
1392                 FN(PW,free)(pw);
1393                 return zero;
1394         }
1395         pw = FN(PW,cow)(pw);
1396         if (!pw)
1397                 return NULL;
1398         if (pw->n == 0)
1399                 return pw;
1400
1401 #ifdef HAS_TYPE
1402         if (isl_int_is_neg(v))
1403                 pw->type = isl_fold_type_negate(pw->type);
1404 #endif
1405         for (i = 0; i < pw->n; ++i) {
1406                 pw->p[i].FIELD = FN(EL,scale)(pw->p[i].FIELD, v);
1407                 if (!pw->p[i].FIELD)
1408                         goto error;
1409         }
1410
1411         return pw;
1412 error:
1413         FN(PW,free)(pw);
1414         return NULL;
1415 }
1416
1417 __isl_give PW *FN(PW,scale)(__isl_take PW *pw, isl_int v)
1418 {
1419         return FN(PW,mul_isl_int)(pw, v);
1420 }
1421
1422 static int FN(PW,qsort_set_cmp)(const void *p1, const void *p2)
1423 {
1424         const isl_set *set1 = *(const isl_set **)p1;
1425         const isl_set *set2 = *(const isl_set **)p2;
1426
1427         return isl_set_plain_cmp(set1, set2);
1428 }
1429
1430 /* We normalize in place, but if anything goes wrong we need
1431  * to return NULL, so we need to make sure we don't change the
1432  * meaning of any possible other copies of map.
1433  */
1434 __isl_give PW *FN(PW,normalize)(__isl_take PW *pw)
1435 {
1436         int i, j;
1437         isl_set *set;
1438
1439         if (!pw)
1440                 return NULL;
1441         for (i = 0; i < pw->n; ++i) {
1442                 set = isl_set_normalize(isl_set_copy(pw->p[i].set));
1443                 if (!set)
1444                         return FN(PW,free)(pw);
1445                 isl_set_free(pw->p[i].set);
1446                 pw->p[i].set = set;
1447         }
1448         qsort(pw->p, pw->n, sizeof(pw->p[0]), &FN(PW,qsort_set_cmp));
1449         for (i = pw->n - 1; i >= 1; --i) {
1450                 if (!isl_set_plain_is_equal(pw->p[i - 1].set, pw->p[i].set))
1451                         continue;
1452                 if (!FN(EL,plain_is_equal)(pw->p[i - 1].FIELD, pw->p[i].FIELD))
1453                         continue;
1454                 set = isl_set_union(isl_set_copy(pw->p[i - 1].set),
1455                                     isl_set_copy(pw->p[i].set));
1456                 if (!set)
1457                         return FN(PW,free)(pw);
1458                 isl_set_free(pw->p[i].set);
1459                 FN(EL,free)(pw->p[i].FIELD);
1460                 isl_set_free(pw->p[i - 1].set);
1461                 pw->p[i - 1].set = set;
1462                 for (j = i + 1; j < pw->n; ++j)
1463                         pw->p[j - 1] = pw->p[j];
1464                 pw->n--;
1465         }
1466
1467         return pw;
1468 }
1469
1470 /* Is pw1 obviously equal to pw2?
1471  * That is, do they have obviously identical cells and obviously identical
1472  * elements on each cell?
1473  */
1474 int FN(PW,plain_is_equal)(__isl_keep PW *pw1, __isl_keep PW *pw2)
1475 {
1476         int i;
1477         int equal;
1478
1479         if (!pw1 || !pw2)
1480                 return -1;
1481
1482         if (pw1 == pw2)
1483                 return 1;
1484         if (!isl_space_is_equal(pw1->dim, pw2->dim))
1485                 return 0;
1486
1487         pw1 = FN(PW,copy)(pw1);
1488         pw2 = FN(PW,copy)(pw2);
1489         pw1 = FN(PW,normalize)(pw1);
1490         pw2 = FN(PW,normalize)(pw2);
1491         if (!pw1 || !pw2)
1492                 goto error;
1493
1494         equal = pw1->n == pw2->n;
1495         for (i = 0; equal && i < pw1->n; ++i) {
1496                 equal = isl_set_plain_is_equal(pw1->p[i].set, pw2->p[i].set);
1497                 if (equal < 0)
1498                         goto error;
1499                 if (!equal)
1500                         break;
1501                 equal = FN(EL,plain_is_equal)(pw1->p[i].FIELD, pw2->p[i].FIELD);
1502                 if (equal < 0)
1503                         goto error;
1504         }
1505
1506         FN(PW,free)(pw1);
1507         FN(PW,free)(pw2);
1508         return equal;
1509 error:
1510         FN(PW,free)(pw1);
1511         FN(PW,free)(pw2);
1512         return -1;
1513 }