xref: /netbsd-src/external/mit/isl/dist/isl_morph.c (revision 5971e316fdea024efff6be8f03536623db06833e)
1 /*
2  * Copyright 2010-2011 INRIA Saclay
3  * Copyright 2014      Ecole Normale Superieure
4  *
5  * Use of this software is governed by the MIT license
6  *
7  * Written by Sven Verdoolaege, INRIA Saclay - Ile-de-France,
8  * Parc Club Orsay Universite, ZAC des vignes, 4 rue Jacques Monod,
9  * 91893 Orsay, France
10  * and Ecole Normale Superieure, 45 rue d'Ulm, 75230 Paris, France
11  */
12 
13 #include <isl_map_private.h>
14 #include <isl_aff_private.h>
15 #include <isl_morph.h>
16 #include <isl_seq.h>
17 #include <isl_mat_private.h>
18 #include <isl_space_private.h>
19 #include <isl_equalities.h>
20 #include <isl_id_private.h>
21 #include <isl_aff_private.h>
22 #include <isl_vec_private.h>
23 
isl_morph_get_ctx(__isl_keep isl_morph * morph)24 isl_ctx *isl_morph_get_ctx(__isl_keep isl_morph *morph)
25 {
26 	if (!morph)
27 		return NULL;
28 	return isl_basic_set_get_ctx(morph->dom);
29 }
30 
isl_morph_alloc(__isl_take isl_basic_set * dom,__isl_take isl_basic_set * ran,__isl_take isl_mat * map,__isl_take isl_mat * inv)31 __isl_give isl_morph *isl_morph_alloc(
32 	__isl_take isl_basic_set *dom, __isl_take isl_basic_set *ran,
33 	__isl_take isl_mat *map, __isl_take isl_mat *inv)
34 {
35 	isl_morph *morph;
36 
37 	if (!dom || !ran || !map || !inv)
38 		goto error;
39 
40 	morph = isl_alloc_type(dom->ctx, struct isl_morph);
41 	if (!morph)
42 		goto error;
43 
44 	morph->ref = 1;
45 	morph->dom = dom;
46 	morph->ran = ran;
47 	morph->map = map;
48 	morph->inv = inv;
49 
50 	return morph;
51 error:
52 	isl_basic_set_free(dom);
53 	isl_basic_set_free(ran);
54 	isl_mat_free(map);
55 	isl_mat_free(inv);
56 	return NULL;
57 }
58 
isl_morph_copy(__isl_keep isl_morph * morph)59 __isl_give isl_morph *isl_morph_copy(__isl_keep isl_morph *morph)
60 {
61 	if (!morph)
62 		return NULL;
63 
64 	morph->ref++;
65 	return morph;
66 }
67 
isl_morph_dup(__isl_keep isl_morph * morph)68 __isl_give isl_morph *isl_morph_dup(__isl_keep isl_morph *morph)
69 {
70 	if (!morph)
71 		return NULL;
72 
73 	return isl_morph_alloc(isl_basic_set_copy(morph->dom),
74 		isl_basic_set_copy(morph->ran),
75 		isl_mat_copy(morph->map), isl_mat_copy(morph->inv));
76 }
77 
isl_morph_cow(__isl_take isl_morph * morph)78 __isl_give isl_morph *isl_morph_cow(__isl_take isl_morph *morph)
79 {
80 	if (!morph)
81 		return NULL;
82 
83 	if (morph->ref == 1)
84 		return morph;
85 	morph->ref--;
86 	return isl_morph_dup(morph);
87 }
88 
isl_morph_free(__isl_take isl_morph * morph)89 __isl_null isl_morph *isl_morph_free(__isl_take isl_morph *morph)
90 {
91 	if (!morph)
92 		return NULL;
93 
94 	if (--morph->ref > 0)
95 		return NULL;
96 
97 	isl_basic_set_free(morph->dom);
98 	isl_basic_set_free(morph->ran);
99 	isl_mat_free(morph->map);
100 	isl_mat_free(morph->inv);
101 	free(morph);
102 
103 	return NULL;
104 }
105 
106 /* Is "morph" an identity on the parameters?
107  */
identity_on_parameters(__isl_keep isl_morph * morph)108 static isl_bool identity_on_parameters(__isl_keep isl_morph *morph)
109 {
110 	isl_bool is_identity;
111 	isl_size nparam, nparam_ran;
112 	isl_mat *sub;
113 
114 	nparam = isl_morph_dom_dim(morph, isl_dim_param);
115 	nparam_ran = isl_morph_ran_dim(morph, isl_dim_param);
116 	if (nparam < 0 || nparam_ran < 0)
117 		return isl_bool_error;
118 	if (nparam != nparam_ran)
119 		return isl_bool_false;
120 	if (nparam == 0)
121 		return isl_bool_true;
122 	sub = isl_mat_sub_alloc(morph->map, 0, 1 + nparam, 0, 1 + nparam);
123 	is_identity = isl_mat_is_scaled_identity(sub);
124 	isl_mat_free(sub);
125 
126 	return is_identity;
127 }
128 
129 /* Return an affine expression of the variables of the range of "morph"
130  * in terms of the parameters and the variables of the domain on "morph".
131  *
132  * In order for the space manipulations to make sense, we require
133  * that the parameters are not modified by "morph".
134  */
isl_morph_get_var_multi_aff(__isl_keep isl_morph * morph)135 __isl_give isl_multi_aff *isl_morph_get_var_multi_aff(
136 	__isl_keep isl_morph *morph)
137 {
138 	isl_space *dom, *ran, *space;
139 	isl_local_space *ls;
140 	isl_multi_aff *ma;
141 	isl_size nparam, nvar;
142 	int i;
143 	isl_bool is_identity;
144 
145 	if (!morph)
146 		return NULL;
147 
148 	is_identity = identity_on_parameters(morph);
149 	if (is_identity < 0)
150 		return NULL;
151 	if (!is_identity)
152 		isl_die(isl_morph_get_ctx(morph), isl_error_invalid,
153 			"cannot handle parameter compression", return NULL);
154 
155 	dom = isl_morph_get_dom_space(morph);
156 	ls = isl_local_space_from_space(isl_space_copy(dom));
157 	ran = isl_morph_get_ran_space(morph);
158 	space = isl_space_map_from_domain_and_range(dom, ran);
159 	ma = isl_multi_aff_zero(space);
160 
161 	nparam = isl_multi_aff_dim(ma, isl_dim_param);
162 	nvar = isl_multi_aff_dim(ma, isl_dim_out);
163 	if (nparam < 0 || nvar < 0)
164 		ma = isl_multi_aff_free(ma);
165 	for (i = 0; i < nvar; ++i) {
166 		isl_val *val;
167 		isl_vec *v;
168 		isl_aff *aff;
169 
170 		v = isl_mat_get_row(morph->map, 1 + nparam + i);
171 		v = isl_vec_insert_els(v, 0, 1);
172 		val = isl_mat_get_element_val(morph->map, 0, 0);
173 		v = isl_vec_set_element_val(v, 0, val);
174 		aff = isl_aff_alloc_vec(isl_local_space_copy(ls), v);
175 		ma = isl_multi_aff_set_aff(ma, i, aff);
176 	}
177 
178 	isl_local_space_free(ls);
179 	return ma;
180 }
181 
182 /* Return the domain space of "morph".
183  */
isl_morph_peek_dom_space(__isl_keep isl_morph * morph)184 static __isl_keep isl_space *isl_morph_peek_dom_space(
185 	__isl_keep isl_morph *morph)
186 {
187 	if (!morph)
188 		return NULL;
189 
190 	return isl_basic_set_peek_space(morph->dom);
191 }
192 
193 /* Return a copy of the domain space of "morph".
194  */
isl_morph_get_dom_space(__isl_keep isl_morph * morph)195 __isl_give isl_space *isl_morph_get_dom_space(__isl_keep isl_morph *morph)
196 {
197 	return isl_space_copy(isl_morph_peek_dom_space(morph));
198 }
199 
200 /* Check that the match against "space" with result "match" was successful.
201  */
check_space_match(__isl_keep isl_space * space,isl_bool match)202 static isl_stat check_space_match(__isl_keep isl_space *space, isl_bool match)
203 {
204 	if (match < 0)
205 		return isl_stat_error;
206 	if (!match)
207 		isl_die(isl_space_get_ctx(space), isl_error_invalid,
208 			"spaces don't match", return isl_stat_error);
209 
210 	return isl_stat_ok;
211 }
212 
213 /* Check that "morph" can be applied to the "space".
214  */
isl_morph_check_applies(__isl_keep isl_morph * morph,__isl_keep isl_space * space)215 isl_stat isl_morph_check_applies(__isl_keep isl_morph *morph,
216 	__isl_keep isl_space *space)
217 {
218 	isl_space *dom_space;
219 	isl_bool applies;
220 
221 	dom_space = isl_morph_peek_dom_space(morph);
222 	applies = isl_space_is_equal(dom_space, space);
223 	return check_space_match(space, applies);
224 }
225 
isl_morph_get_ran_space(__isl_keep isl_morph * morph)226 __isl_give isl_space *isl_morph_get_ran_space(__isl_keep isl_morph *morph)
227 {
228 	if (!morph)
229 		return NULL;
230 
231 	return isl_space_copy(morph->ran->dim);
232 }
233 
isl_morph_dom_dim(__isl_keep isl_morph * morph,enum isl_dim_type type)234 isl_size isl_morph_dom_dim(__isl_keep isl_morph *morph, enum isl_dim_type type)
235 {
236 	if (!morph)
237 		return isl_size_error;
238 
239 	return isl_basic_set_dim(morph->dom, type);
240 }
241 
isl_morph_ran_dim(__isl_keep isl_morph * morph,enum isl_dim_type type)242 isl_size isl_morph_ran_dim(__isl_keep isl_morph *morph, enum isl_dim_type type)
243 {
244 	if (!morph)
245 		return isl_size_error;
246 
247 	return isl_basic_set_dim(morph->ran, type);
248 }
249 
isl_morph_remove_dom_dims(__isl_take isl_morph * morph,enum isl_dim_type type,unsigned first,unsigned n)250 __isl_give isl_morph *isl_morph_remove_dom_dims(__isl_take isl_morph *morph,
251 	enum isl_dim_type type, unsigned first, unsigned n)
252 {
253 	isl_size dom_offset;
254 
255 	if (n == 0)
256 		return morph;
257 
258 	morph = isl_morph_cow(morph);
259 	if (!morph)
260 		return NULL;
261 
262 	dom_offset = isl_space_offset(morph->dom->dim, type);
263 	if (dom_offset < 0)
264 		return isl_morph_free(morph);
265 
266 	morph->dom = isl_basic_set_remove_dims(morph->dom, type, first, n);
267 
268 	morph->map = isl_mat_drop_cols(morph->map, 1 + dom_offset + first, n);
269 
270 	morph->inv = isl_mat_drop_rows(morph->inv, 1 + dom_offset + first, n);
271 
272 	if (morph->dom && morph->ran && morph->map && morph->inv)
273 		return morph;
274 
275 	isl_morph_free(morph);
276 	return NULL;
277 }
278 
isl_morph_remove_ran_dims(__isl_take isl_morph * morph,enum isl_dim_type type,unsigned first,unsigned n)279 __isl_give isl_morph *isl_morph_remove_ran_dims(__isl_take isl_morph *morph,
280 	enum isl_dim_type type, unsigned first, unsigned n)
281 {
282 	isl_size ran_offset;
283 
284 	if (n == 0)
285 		return morph;
286 
287 	morph = isl_morph_cow(morph);
288 	if (!morph)
289 		return NULL;
290 
291 	ran_offset = isl_space_offset(morph->ran->dim, type);
292 	if (ran_offset < 0)
293 		return isl_morph_free(morph);
294 
295 	morph->ran = isl_basic_set_remove_dims(morph->ran, type, first, n);
296 
297 	morph->map = isl_mat_drop_rows(morph->map, 1 + ran_offset + first, n);
298 
299 	morph->inv = isl_mat_drop_cols(morph->inv, 1 + ran_offset + first, n);
300 
301 	if (morph->dom && morph->ran && morph->map && morph->inv)
302 		return morph;
303 
304 	isl_morph_free(morph);
305 	return NULL;
306 }
307 
308 /* Project domain of morph onto its parameter domain.
309  */
isl_morph_dom_params(__isl_take isl_morph * morph)310 __isl_give isl_morph *isl_morph_dom_params(__isl_take isl_morph *morph)
311 {
312 	isl_size n;
313 
314 	morph = isl_morph_cow(morph);
315 	if (!morph)
316 		return NULL;
317 	n = isl_basic_set_dim(morph->dom, isl_dim_set);
318 	if (n < 0)
319 		return isl_morph_free(morph);
320 	morph = isl_morph_remove_dom_dims(morph, isl_dim_set, 0, n);
321 	if (!morph)
322 		return NULL;
323 	morph->dom = isl_basic_set_params(morph->dom);
324 	if (morph->dom)
325 		return morph;
326 
327 	isl_morph_free(morph);
328 	return NULL;
329 }
330 
331 /* Project range of morph onto its parameter domain.
332  */
isl_morph_ran_params(__isl_take isl_morph * morph)333 __isl_give isl_morph *isl_morph_ran_params(__isl_take isl_morph *morph)
334 {
335 	isl_size n;
336 
337 	morph = isl_morph_cow(morph);
338 	if (!morph)
339 		return NULL;
340 	n = isl_basic_set_dim(morph->ran, isl_dim_set);
341 	if (n < 0)
342 		return isl_morph_free(morph);
343 	morph = isl_morph_remove_ran_dims(morph, isl_dim_set, 0, n);
344 	if (!morph)
345 		return NULL;
346 	morph->ran = isl_basic_set_params(morph->ran);
347 	if (morph->ran)
348 		return morph;
349 
350 	isl_morph_free(morph);
351 	return NULL;
352 }
353 
354 /* Replace the identifier of the tuple of the range of the morph by "id".
355  */
isl_morph_set_ran_tuple_id(__isl_take isl_morph * morph,__isl_keep isl_id * id)356 static __isl_give isl_morph *isl_morph_set_ran_tuple_id(
357 	__isl_take isl_morph *morph, __isl_keep isl_id *id)
358 {
359 	morph = isl_morph_cow(morph);
360 	if (!morph)
361 		return NULL;
362 	morph->ran = isl_basic_set_set_tuple_id(morph->ran, isl_id_copy(id));
363 	if (!morph->ran)
364 		return isl_morph_free(morph);
365 	return morph;
366 }
367 
isl_morph_print_internal(__isl_take isl_morph * morph,FILE * out)368 void isl_morph_print_internal(__isl_take isl_morph *morph, FILE *out)
369 {
370 	if (!morph)
371 		return;
372 
373 	isl_basic_set_dump(morph->dom);
374 	isl_basic_set_dump(morph->ran);
375 	isl_mat_print_internal(morph->map, out, 4);
376 	isl_mat_print_internal(morph->inv, out, 4);
377 }
378 
isl_morph_dump(__isl_take isl_morph * morph)379 void isl_morph_dump(__isl_take isl_morph *morph)
380 {
381 	isl_morph_print_internal(morph, stderr);
382 }
383 
isl_morph_identity(__isl_keep isl_basic_set * bset)384 __isl_give isl_morph *isl_morph_identity(__isl_keep isl_basic_set *bset)
385 {
386 	isl_mat *id;
387 	isl_basic_set *universe;
388 	isl_size total;
389 
390 	total = isl_basic_set_dim(bset, isl_dim_all);
391 	if (total < 0)
392 		return NULL;
393 
394 	id = isl_mat_identity(bset->ctx, 1 + total);
395 	universe = isl_basic_set_universe(isl_space_copy(bset->dim));
396 
397 	return isl_morph_alloc(universe, isl_basic_set_copy(universe),
398 		id, isl_mat_copy(id));
399 }
400 
401 /* Create a(n identity) morphism between empty sets of the same dimension
402  * a "bset".
403  */
isl_morph_empty(__isl_keep isl_basic_set * bset)404 __isl_give isl_morph *isl_morph_empty(__isl_keep isl_basic_set *bset)
405 {
406 	isl_mat *id;
407 	isl_basic_set *empty;
408 	isl_size total;
409 
410 	total = isl_basic_set_dim(bset, isl_dim_all);
411 	if (total < 0)
412 		return NULL;
413 
414 	id = isl_mat_identity(bset->ctx, 1 + total);
415 	empty = isl_basic_set_empty(isl_space_copy(bset->dim));
416 
417 	return isl_morph_alloc(empty, isl_basic_set_copy(empty),
418 		id, isl_mat_copy(id));
419 }
420 
421 /* Construct a basic set described by the "n" equalities of "bset" starting
422  * at "first".
423  */
copy_equalities(__isl_keep isl_basic_set * bset,unsigned first,unsigned n)424 static __isl_give isl_basic_set *copy_equalities(__isl_keep isl_basic_set *bset,
425 	unsigned first, unsigned n)
426 {
427 	int i, k;
428 	isl_basic_set *eq;
429 	isl_size total;
430 
431 	total = isl_basic_set_dim(bset, isl_dim_all);
432 	if (total < 0 || isl_basic_set_check_no_locals(bset) < 0)
433 		return NULL;
434 
435 	eq = isl_basic_set_alloc_space(isl_basic_set_get_space(bset), 0, n, 0);
436 	if (!eq)
437 		return NULL;
438 	for (i = 0; i < n; ++i) {
439 		k = isl_basic_set_alloc_equality(eq);
440 		if (k < 0)
441 			goto error;
442 		isl_seq_cpy(eq->eq[k], bset->eq[first + i], 1 + total);
443 	}
444 
445 	return eq;
446 error:
447 	isl_basic_set_free(eq);
448 	return NULL;
449 }
450 
451 /* Given a basic set, exploit the equalities in the basic set to construct
452  * a morphism that maps the basic set to a lower-dimensional space.
453  * Specifically, the morphism reduces the number of dimensions of type "type".
454  *
455  * We first select the equalities of interest, that is those that involve
456  * variables of type "type" and no later variables.
457  * Denote those equalities as
458  *
459  *		-C(p) + M x = 0
460  *
461  * where C(p) depends on the parameters if type == isl_dim_set and
462  * is a constant if type == isl_dim_param.
463  *
464  * Use isl_mat_final_variable_compression to construct a compression
465  *
466  *	x = T x'
467  *
468  *	x' = Q x
469  *
470  * If T is a zero-column matrix, then the set of equality constraints
471  * do not admit a solution.  In this case, an empty morphism is returned.
472  *
473  * Both matrices are extended to map the full original space to the full
474  * compressed space.
475  */
isl_basic_set_variable_compression(__isl_keep isl_basic_set * bset,enum isl_dim_type type)476 __isl_give isl_morph *isl_basic_set_variable_compression(
477 	__isl_keep isl_basic_set *bset, enum isl_dim_type type)
478 {
479 	unsigned otype;
480 	isl_size ntype;
481 	unsigned orest;
482 	unsigned nrest;
483 	isl_size total;
484 	int f_eq, n_eq;
485 	isl_space *space;
486 	isl_mat *E, *Q, *C;
487 	isl_basic_set *dom, *ran;
488 
489 	if (!bset)
490 		return NULL;
491 
492 	if (isl_basic_set_plain_is_empty(bset))
493 		return isl_morph_empty(bset);
494 
495 	if (isl_basic_set_check_no_locals(bset) < 0)
496 		return NULL;
497 
498 	ntype = isl_basic_set_dim(bset, type);
499 	total = isl_basic_set_dim(bset, isl_dim_all);
500 	if (ntype < 0 || total < 0)
501 		return NULL;
502 	otype = isl_basic_set_offset(bset, type);
503 	orest = otype + ntype;
504 	nrest = total - (orest - 1);
505 
506 	for (f_eq = 0; f_eq < bset->n_eq; ++f_eq)
507 		if (isl_seq_first_non_zero(bset->eq[f_eq] + orest, nrest) == -1)
508 			break;
509 	for (n_eq = 0; f_eq + n_eq < bset->n_eq; ++n_eq)
510 		if (isl_seq_first_non_zero(bset->eq[f_eq + n_eq] + otype, ntype) == -1)
511 			break;
512 	if (n_eq == 0)
513 		return isl_morph_identity(bset);
514 
515 	E = isl_mat_sub_alloc6(bset->ctx, bset->eq, f_eq, n_eq, 0, orest);
516 	C = isl_mat_final_variable_compression(E, otype - 1, &Q);
517 	if (!Q)
518 		C = isl_mat_free(C);
519 	if (C && C->n_col == 0) {
520 		isl_mat_free(C);
521 		isl_mat_free(Q);
522 		return isl_morph_empty(bset);
523 	}
524 
525 	Q = isl_mat_diagonal(Q, isl_mat_identity(bset->ctx, nrest));
526 	C = isl_mat_diagonal(C, isl_mat_identity(bset->ctx, nrest));
527 
528 	space = isl_space_copy(bset->dim);
529 	space = isl_space_drop_dims(space, type, 0, ntype);
530 	space = isl_space_add_dims(space, type, ntype - n_eq);
531 	ran = isl_basic_set_universe(space);
532 	dom = copy_equalities(bset, f_eq, n_eq);
533 
534 	return isl_morph_alloc(dom, ran, Q, C);
535 }
536 
537 /* Given a basic set, exploit the equalities in the basic set to construct
538  * a morphism that maps the basic set to a lower-dimensional space
539  * with identifier "id".
540  * Specifically, the morphism reduces the number of set dimensions.
541  */
isl_basic_set_variable_compression_with_id(__isl_keep isl_basic_set * bset,__isl_keep isl_id * id)542 __isl_give isl_morph *isl_basic_set_variable_compression_with_id(
543 	__isl_keep isl_basic_set *bset, __isl_keep isl_id *id)
544 {
545 	isl_morph *morph;
546 
547 	morph = isl_basic_set_variable_compression(bset, isl_dim_set);
548 	morph = isl_morph_set_ran_tuple_id(morph, id);
549 	return morph;
550 }
551 
552 /* Construct a parameter compression for "bset".
553  * We basically just call isl_mat_parameter_compression with the right input
554  * and then extend the resulting matrix to include the variables.
555  *
556  * The implementation assumes that "bset" does not have any equalities
557  * that only involve the parameters and that isl_basic_set_gauss has
558  * been applied to "bset".
559  *
560  * Let the equalities be given as
561  *
562  *	B(p) + A x = 0.
563  *
564  * We use isl_mat_parameter_compression_ext to compute the compression
565  *
566  *	p = T p'.
567  */
isl_basic_set_parameter_compression(__isl_keep isl_basic_set * bset)568 __isl_give isl_morph *isl_basic_set_parameter_compression(
569 	__isl_keep isl_basic_set *bset)
570 {
571 	isl_size nparam;
572 	isl_size nvar;
573 	isl_size n_div;
574 	int n_eq;
575 	isl_mat *H, *B;
576 	isl_mat *map, *inv;
577 	isl_basic_set *dom, *ran;
578 
579 	if (!bset)
580 		return NULL;
581 
582 	if (isl_basic_set_plain_is_empty(bset))
583 		return isl_morph_empty(bset);
584 	if (bset->n_eq == 0)
585 		return isl_morph_identity(bset);
586 
587 	n_eq = bset->n_eq;
588 	nparam = isl_basic_set_dim(bset, isl_dim_param);
589 	nvar = isl_basic_set_dim(bset, isl_dim_set);
590 	n_div = isl_basic_set_dim(bset, isl_dim_div);
591 	if (nparam < 0 || nvar < 0 || n_div < 0)
592 		return NULL;
593 
594 	if (isl_seq_first_non_zero(bset->eq[bset->n_eq - 1] + 1 + nparam,
595 				    nvar + n_div) == -1)
596 		isl_die(isl_basic_set_get_ctx(bset), isl_error_invalid,
597 			"input not allowed to have parameter equalities",
598 			return NULL);
599 	if (n_eq > nvar + n_div)
600 		isl_die(isl_basic_set_get_ctx(bset), isl_error_invalid,
601 			"input not gaussed", return NULL);
602 
603 	B = isl_mat_sub_alloc6(bset->ctx, bset->eq, 0, n_eq, 0, 1 + nparam);
604 	H = isl_mat_sub_alloc6(bset->ctx, bset->eq,
605 				0, n_eq, 1 + nparam, nvar + n_div);
606 	inv = isl_mat_parameter_compression_ext(B, H);
607 	inv = isl_mat_diagonal(inv, isl_mat_identity(bset->ctx, nvar));
608 	map = isl_mat_right_inverse(isl_mat_copy(inv));
609 
610 	dom = isl_basic_set_universe(isl_space_copy(bset->dim));
611 	ran = isl_basic_set_universe(isl_space_copy(bset->dim));
612 
613 	return isl_morph_alloc(dom, ran, map, inv);
614 }
615 
616 /* Construct an isl_multi_aff that corresponds
617  * to the affine transformation matrix "mat" and
618  * that lives in an anonymous space.
619  */
isl_multi_aff_from_aff_mat_anonymous(__isl_take isl_mat * mat)620 static __isl_give isl_multi_aff *isl_multi_aff_from_aff_mat_anonymous(
621 	__isl_take isl_mat *mat)
622 {
623 	isl_size n_row, n_col;
624 	isl_ctx *ctx;
625 	isl_space *space;
626 
627 	ctx = isl_mat_get_ctx(mat);
628 	n_row = isl_mat_rows(mat);
629 	n_col = isl_mat_cols(mat);
630 	if (n_row < 0 || n_col < 0)
631 		space = NULL;
632 	else
633 		space = isl_space_alloc(ctx, 0, n_col - 1, n_row - 1);
634 
635 	return isl_multi_aff_from_aff_mat(space, mat);
636 }
637 
638 /* Apply the morphism to the basic set.
639  * In particular, compute the preimage of "bset" under the inverse mapping
640  * in morph and intersect with the range of the morphism.
641  * Note that the mapping in morph applies to both parameters and set dimensions,
642  * so the parameters need to be treated as set dimensions during the call
643  * to isl_basic_set_preimage_multi_aff.
644  */
isl_morph_basic_set(__isl_take isl_morph * morph,__isl_take isl_basic_set * bset)645 __isl_give isl_basic_set *isl_morph_basic_set(__isl_take isl_morph *morph,
646 	__isl_take isl_basic_set *bset)
647 {
648 	isl_size n_param;
649 	isl_space *space;
650 	isl_multi_aff *ma;
651 
652 	if (!morph || isl_basic_set_check_equal_space(bset, morph->dom) < 0)
653 		goto error;
654 	n_param = isl_basic_set_dim(morph->dom, isl_dim_param);
655 	if (n_param < 0)
656 		goto error;
657 
658 	ma = isl_multi_aff_from_aff_mat_anonymous(isl_mat_copy(morph->inv));
659 
660 	bset = isl_basic_set_move_dims(bset, isl_dim_set, 0,
661 					isl_dim_param, 0, n_param);
662 	bset = isl_basic_set_preimage_multi_aff(bset, ma);
663 	space = isl_basic_set_get_space(morph->ran);
664 	bset = isl_basic_set_reset_space(bset, space);
665 	bset = isl_basic_set_intersect(bset, isl_basic_set_copy(morph->ran));
666 
667 	isl_morph_free(morph);
668 	return bset;
669 error:
670 	isl_morph_free(morph);
671 	isl_basic_set_free(bset);
672 	return NULL;
673 }
674 
675 /* Apply the morphism to the set.
676  * In particular, compute the preimage of "set" under the inverse mapping
677  * in morph and intersect with the range of the morphism.
678  * Note that the mapping in morph applies to both parameters and set dimensions,
679  * so the parameters need to be treated as set dimensions during the call
680  * to isl_set_preimage_multi_aff.
681  */
isl_morph_set(__isl_take isl_morph * morph,__isl_take isl_set * set)682 __isl_give isl_set *isl_morph_set(__isl_take isl_morph *morph,
683 	__isl_take isl_set *set)
684 {
685 	isl_size n_param;
686 	isl_space *space;
687 	isl_multi_aff *ma;
688 	isl_basic_set *ran;
689 
690 	if (!morph || isl_set_basic_set_check_equal_space(set, morph->dom) < 0)
691 		goto error;
692 	n_param = isl_basic_set_dim(morph->dom, isl_dim_param);
693 	if (n_param < 0)
694 		goto error;
695 
696 	ma = isl_multi_aff_from_aff_mat_anonymous(isl_mat_copy(morph->inv));
697 
698 	set = isl_set_move_dims(set, isl_dim_set, 0, isl_dim_param, 0, n_param);
699 	set = isl_set_preimage_multi_aff(set, ma);
700 	space = isl_basic_set_get_space(morph->ran);
701 	set = isl_set_reset_space(set, space);
702 	ran = isl_basic_set_copy(morph->ran);
703 	set = isl_set_intersect(set, isl_set_from_basic_set(ran));
704 
705 	isl_morph_free(morph);
706 	return set;
707 error:
708 	isl_set_free(set);
709 	isl_morph_free(morph);
710 	return NULL;
711 }
712 
713 /* Construct a morphism that first does morph2 and then morph1.
714  */
isl_morph_compose(__isl_take isl_morph * morph1,__isl_take isl_morph * morph2)715 __isl_give isl_morph *isl_morph_compose(__isl_take isl_morph *morph1,
716 	__isl_take isl_morph *morph2)
717 {
718 	isl_mat *map, *inv;
719 	isl_basic_set *dom, *ran;
720 
721 	if (!morph1 || !morph2)
722 		goto error;
723 
724 	map = isl_mat_product(isl_mat_copy(morph1->map), isl_mat_copy(morph2->map));
725 	inv = isl_mat_product(isl_mat_copy(morph2->inv), isl_mat_copy(morph1->inv));
726 	dom = isl_morph_basic_set(isl_morph_inverse(isl_morph_copy(morph2)),
727 				  isl_basic_set_copy(morph1->dom));
728 	dom = isl_basic_set_intersect(dom, isl_basic_set_copy(morph2->dom));
729 	ran = isl_morph_basic_set(isl_morph_copy(morph1),
730 				  isl_basic_set_copy(morph2->ran));
731 	ran = isl_basic_set_intersect(ran, isl_basic_set_copy(morph1->ran));
732 
733 	isl_morph_free(morph1);
734 	isl_morph_free(morph2);
735 
736 	return isl_morph_alloc(dom, ran, map, inv);
737 error:
738 	isl_morph_free(morph1);
739 	isl_morph_free(morph2);
740 	return NULL;
741 }
742 
isl_morph_inverse(__isl_take isl_morph * morph)743 __isl_give isl_morph *isl_morph_inverse(__isl_take isl_morph *morph)
744 {
745 	isl_basic_set *bset;
746 	isl_mat *mat;
747 
748 	morph = isl_morph_cow(morph);
749 	if (!morph)
750 		return NULL;
751 
752 	bset = morph->dom;
753 	morph->dom = morph->ran;
754 	morph->ran = bset;
755 
756 	mat = morph->map;
757 	morph->map = morph->inv;
758 	morph->inv = mat;
759 
760 	return morph;
761 }
762 
763 /* We detect all the equalities first to avoid implicit equalities
764  * being discovered during the computations.  In particular,
765  * the compression on the variables could expose additional stride
766  * constraints on the parameters.  This would result in existentially
767  * quantified variables after applying the resulting morph, which
768  * in turn could break invariants of the calling functions.
769  */
isl_basic_set_full_compression(__isl_keep isl_basic_set * bset)770 __isl_give isl_morph *isl_basic_set_full_compression(
771 	__isl_keep isl_basic_set *bset)
772 {
773 	isl_morph *morph, *morph2;
774 
775 	bset = isl_basic_set_copy(bset);
776 	bset = isl_basic_set_detect_equalities(bset);
777 
778 	morph = isl_basic_set_variable_compression(bset, isl_dim_param);
779 	bset = isl_morph_basic_set(isl_morph_copy(morph), bset);
780 
781 	morph2 = isl_basic_set_parameter_compression(bset);
782 	bset = isl_morph_basic_set(isl_morph_copy(morph2), bset);
783 
784 	morph = isl_morph_compose(morph2, morph);
785 
786 	morph2 = isl_basic_set_variable_compression(bset, isl_dim_set);
787 	isl_basic_set_free(bset);
788 
789 	morph = isl_morph_compose(morph2, morph);
790 
791 	return morph;
792 }
793 
isl_morph_vec(__isl_take isl_morph * morph,__isl_take isl_vec * vec)794 __isl_give isl_vec *isl_morph_vec(__isl_take isl_morph *morph,
795 	__isl_take isl_vec *vec)
796 {
797 	if (!morph)
798 		goto error;
799 
800 	vec = isl_mat_vec_product(isl_mat_copy(morph->map), vec);
801 
802 	isl_morph_free(morph);
803 	return vec;
804 error:
805 	isl_morph_free(morph);
806 	isl_vec_free(vec);
807 	return NULL;
808 }
809