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 <assert.h>
11 #include <string.h>
12 #include <isl_map_private.h>
13 #include <isl/aff.h>
14 #include <isl/set.h>
15 #include "isl_sample.h"
16 #include "isl_scan.h"
17 #include <isl_seq.h>
18 #include <isl_ilp_private.h>
19 #include <isl/printer.h>
20 #include <isl_point_private.h>
21 #include <isl_vec_private.h>
22 #include <isl/options.h>
23 #include <isl_config.h>
24
25 /* The input of this program is the same as that of the "example" program
26 * from the PipLib distribution, except that the "big parameter column"
27 * should always be -1.
28 *
29 * Context constraints in PolyLib format
30 * -1
31 * Problem constraints in PolyLib format
32 * Optional list of options
33 *
34 * The options are
35 * Maximize compute maximum instead of minimum
36 * Rational compute rational optimum instead of integer optimum
37 * Urs_parms don't assume parameters are non-negative
38 * Urs_unknowns don't assume unknowns are non-negative
39 */
40
41 struct options {
42 struct isl_options *isl;
43 unsigned verify;
44 unsigned format;
45 };
46
47 #define FORMAT_SET 0
48 #define FORMAT_AFF 1
49
50 struct isl_arg_choice pip_format[] = {
51 {"set", FORMAT_SET},
52 {"affine", FORMAT_AFF},
53 {0}
54 };
55
ISL_ARGS_START(struct options,options_args)56 ISL_ARGS_START(struct options, options_args)
57 ISL_ARG_CHILD(struct options, isl, "isl", &isl_options_args, "isl options")
58 ISL_ARG_BOOL(struct options, verify, 'T', "verify", 0, NULL)
59 ISL_ARG_CHOICE(struct options, format, 0, "format",
60 pip_format, FORMAT_SET, "output format")
61 ISL_ARGS_END
62
63 ISL_ARG_DEF(options, struct options, options_args)
64
65 static __isl_give isl_basic_set *set_bounds(__isl_take isl_basic_set *bset)
66 {
67 isl_size nparam;
68 int i, r;
69 isl_point *pt, *pt2;
70 isl_basic_set *box;
71
72 nparam = isl_basic_set_dim(bset, isl_dim_param);
73 if (nparam < 0)
74 return isl_basic_set_free(bset);
75 r = nparam >= 8 ? 4 : nparam >= 5 ? 6 : 30;
76
77 pt = isl_basic_set_sample_point(isl_basic_set_copy(bset));
78 pt2 = isl_point_copy(pt);
79
80 for (i = 0; i < nparam; ++i) {
81 pt = isl_point_add_ui(pt, isl_dim_param, i, r);
82 pt2 = isl_point_sub_ui(pt2, isl_dim_param, i, r);
83 }
84
85 box = isl_basic_set_box_from_points(pt, pt2);
86
87 return isl_basic_set_intersect(bset, box);
88 }
89
to_parameter_domain(__isl_take isl_basic_set * context)90 static __isl_give isl_basic_set *to_parameter_domain(
91 __isl_take isl_basic_set *context)
92 {
93 isl_size dim;
94
95 dim = isl_basic_set_dim(context, isl_dim_set);
96 if (dim < 0)
97 return isl_basic_set_free(context);
98 context = isl_basic_set_move_dims(context, isl_dim_param, 0,
99 isl_dim_set, 0, dim);
100 context = isl_basic_set_params(context);
101 return context;
102 }
103
104 /* If "context" has more parameters than "bset", then reinterpret
105 * the last dimensions of "bset" as parameters.
106 */
move_parameters(__isl_take isl_basic_set * bset,__isl_keep isl_basic_set * context)107 static __isl_give isl_basic_set *move_parameters(__isl_take isl_basic_set *bset,
108 __isl_keep isl_basic_set *context)
109 {
110 isl_size nparam, nparam_bset, dim;
111
112 nparam = isl_basic_set_dim(context, isl_dim_param);
113 nparam_bset = isl_basic_set_dim(bset, isl_dim_param);
114 if (nparam < 0 || nparam_bset < 0)
115 return isl_basic_set_free(bset);
116 if (nparam == nparam_bset)
117 return bset;
118 dim = isl_basic_set_dim(bset, isl_dim_set);
119 if (dim < 0)
120 return isl_basic_set_free(bset);
121 bset = isl_basic_set_move_dims(bset, isl_dim_param, 0,
122 isl_dim_set, dim - nparam, nparam);
123 return bset;
124 }
125
126 /* Plug in the initial values of "params" for the parameters in "bset" and
127 * return the result. The remaining entries in "params", if any,
128 * correspond to the existentially quantified variables in the description
129 * of the original context and can be ignored.
130 */
plug_in_parameters(__isl_take isl_basic_set * bset,__isl_take isl_vec * params)131 static __isl_give isl_basic_set *plug_in_parameters(
132 __isl_take isl_basic_set *bset, __isl_take isl_vec *params)
133 {
134 int i;
135 isl_size n;
136
137 n = isl_basic_set_dim(bset, isl_dim_param);
138 if (n < 0)
139 bset = isl_basic_set_free(bset);
140 for (i = 0; i < n; ++i)
141 bset = isl_basic_set_fix(bset,
142 isl_dim_param, i, params->el[1 + i]);
143
144 bset = isl_basic_set_remove_dims(bset, isl_dim_param, 0, n);
145
146 isl_vec_free(params);
147
148 return bset;
149 }
150
151 /* Plug in the initial values of "params" for the parameters in "set" and
152 * return the result. The remaining entries in "params", if any,
153 * correspond to the existentially quantified variables in the description
154 * of the original context and can be ignored.
155 */
set_plug_in_parameters(__isl_take isl_set * set,__isl_take isl_vec * params)156 static __isl_give isl_set *set_plug_in_parameters(__isl_take isl_set *set,
157 __isl_take isl_vec *params)
158 {
159 int i;
160 isl_size n;
161
162 n = isl_set_dim(set, isl_dim_param);
163 if (n < 0)
164 set = isl_set_free(set);
165 for (i = 0; i < n; ++i)
166 set = isl_set_fix(set, isl_dim_param, i, params->el[1 + i]);
167
168 set = isl_set_remove_dims(set, isl_dim_param, 0, n);
169
170 isl_vec_free(params);
171
172 return set;
173 }
174
175 /* Compute the lexicographically minimal (or maximal if max is set)
176 * element of bset for the given values of the parameters, by
177 * successively solving an ilp problem in each direction.
178 */
opt_at(__isl_take isl_basic_set * bset,__isl_take isl_vec * params,int max)179 static __isl_give isl_vec *opt_at(__isl_take isl_basic_set *bset,
180 __isl_take isl_vec *params, int max)
181 {
182 isl_size dim;
183 isl_ctx *ctx;
184 struct isl_vec *opt;
185 struct isl_vec *obj;
186 int i;
187
188 dim = isl_basic_set_dim(bset, isl_dim_set);
189 if (dim < 0)
190 goto error;
191
192 bset = plug_in_parameters(bset, params);
193
194 ctx = isl_basic_set_get_ctx(bset);
195 if (isl_basic_set_plain_is_empty(bset)) {
196 opt = isl_vec_alloc(ctx, 0);
197 isl_basic_set_free(bset);
198 return opt;
199 }
200
201 opt = isl_vec_alloc(ctx, 1 + dim);
202 assert(opt);
203
204 obj = isl_vec_alloc(ctx, 1 + dim);
205 assert(obj);
206
207 isl_int_set_si(opt->el[0], 1);
208 isl_int_set_si(obj->el[0], 0);
209
210 for (i = 0; i < dim; ++i) {
211 enum isl_lp_result res;
212
213 isl_seq_clr(obj->el + 1, dim);
214 isl_int_set_si(obj->el[1 + i], 1);
215 res = isl_basic_set_solve_ilp(bset, max, obj->el,
216 &opt->el[1 + i], NULL);
217 if (res == isl_lp_empty)
218 goto empty;
219 assert(res == isl_lp_ok);
220 bset = isl_basic_set_fix(bset, isl_dim_set, i, opt->el[1 + i]);
221 }
222
223 isl_basic_set_free(bset);
224 isl_vec_free(obj);
225
226 return opt;
227 error:
228 isl_basic_set_free(bset);
229 isl_vec_free(params);
230 return NULL;
231 empty:
232 isl_vec_free(opt);
233 opt = isl_vec_alloc(ctx, 0);
234 isl_basic_set_free(bset);
235 isl_vec_free(obj);
236
237 return opt;
238 }
239
240 struct isl_scan_pip {
241 struct isl_scan_callback callback;
242 isl_basic_set *bset;
243 isl_set *sol;
244 isl_set *empty;
245 int stride;
246 int n;
247 int max;
248 };
249
250 /* Check if the "manually" computed optimum of bset at the "sample"
251 * values of the parameters agrees with the solution of pilp problem
252 * represented by the pair (sol, empty).
253 * In particular, if there is no solution for this value of the parameters,
254 * then it should be an element of the parameter domain "empty".
255 * Otherwise, the optimal solution, should be equal to the result of
256 * plugging in the value of the parameters in "sol".
257 */
scan_one(struct isl_scan_callback * callback,__isl_take isl_vec * sample)258 static isl_stat scan_one(struct isl_scan_callback *callback,
259 __isl_take isl_vec *sample)
260 {
261 struct isl_scan_pip *sp = (struct isl_scan_pip *)callback;
262 struct isl_vec *opt;
263
264 sp->n--;
265
266 opt = opt_at(isl_basic_set_copy(sp->bset), isl_vec_copy(sample), sp->max);
267 assert(opt);
268
269 if (opt->size == 0) {
270 isl_point *sample_pnt;
271 sample_pnt = isl_point_alloc(isl_set_get_space(sp->empty), sample);
272 assert(isl_set_contains_point(sp->empty, sample_pnt));
273 isl_point_free(sample_pnt);
274 isl_vec_free(opt);
275 } else {
276 isl_set *sol;
277 isl_set *opt_set;
278 opt_set = isl_set_from_basic_set(isl_basic_set_from_vec(opt));
279 sol = set_plug_in_parameters(isl_set_copy(sp->sol), sample);
280 assert(isl_set_is_equal(opt_set, sol));
281 isl_set_free(sol);
282 isl_set_free(opt_set);
283 }
284
285 if (!(sp->n % sp->stride)) {
286 printf("o");
287 fflush(stdout);
288 }
289
290 return sp->n >= 1 ? isl_stat_ok : isl_stat_error;
291 }
292
check_solution(isl_basic_set * bset,isl_basic_set * context,isl_set * sol,isl_set * empty,int max)293 static void check_solution(isl_basic_set *bset, isl_basic_set *context,
294 isl_set *sol, isl_set *empty, int max)
295 {
296 struct isl_scan_pip sp;
297 isl_int count, count_max;
298 int i, n;
299 int r;
300
301 context = set_bounds(context);
302 context = isl_basic_set_underlying_set(context);
303
304 isl_int_init(count);
305 isl_int_init(count_max);
306
307 isl_int_set_si(count_max, 2000);
308 r = isl_basic_set_count_upto(context, count_max, &count);
309 assert(r >= 0);
310 n = isl_int_get_si(count);
311
312 isl_int_clear(count_max);
313 isl_int_clear(count);
314
315 sp.callback.add = scan_one;
316 sp.bset = bset;
317 sp.sol = sol;
318 sp.empty = empty;
319 sp.n = n;
320 sp.stride = n > 70 ? 1 + (n + 1)/70 : 1;
321 sp.max = max;
322
323 for (i = 0; i < n; i += sp.stride)
324 printf(".");
325 printf("\r");
326 fflush(stdout);
327
328 isl_basic_set_scan(context, &sp.callback);
329
330 printf("\n");
331
332 isl_basic_set_free(bset);
333 }
334
main(int argc,char ** argv)335 int main(int argc, char **argv)
336 {
337 struct isl_ctx *ctx;
338 struct isl_basic_set *context, *bset, *copy, *context_copy;
339 struct isl_set *set = NULL;
340 struct isl_set *empty;
341 isl_pw_multi_aff *pma = NULL;
342 int neg_one;
343 char s[1024];
344 int urs_parms = 0;
345 int urs_unknowns = 0;
346 int max = 0;
347 int rational = 0;
348 int n;
349 struct options *options;
350
351 options = options_new_with_defaults();
352 assert(options);
353 argc = options_parse(options, argc, argv, ISL_ARG_ALL);
354
355 ctx = isl_ctx_alloc_with_options(&options_args, options);
356
357 context = isl_basic_set_read_from_file(ctx, stdin);
358 assert(context);
359 n = fscanf(stdin, "%d", &neg_one);
360 assert(n == 1);
361 assert(neg_one == -1);
362 bset = isl_basic_set_read_from_file(ctx, stdin);
363
364 while (fgets(s, sizeof(s), stdin)) {
365 if (strncasecmp(s, "Maximize", 8) == 0)
366 max = 1;
367 if (strncasecmp(s, "Rational", 8) == 0) {
368 rational = 1;
369 bset = isl_basic_set_set_rational(bset);
370 }
371 if (strncasecmp(s, "Urs_parms", 9) == 0)
372 urs_parms = 1;
373 if (strncasecmp(s, "Urs_unknowns", 12) == 0)
374 urs_unknowns = 1;
375 }
376 if (!urs_parms)
377 context = isl_basic_set_intersect(context,
378 isl_basic_set_positive_orthant(isl_basic_set_get_space(context)));
379 context = to_parameter_domain(context);
380 bset = move_parameters(bset, context);
381 if (!urs_unknowns)
382 bset = isl_basic_set_intersect(bset,
383 isl_basic_set_positive_orthant(isl_basic_set_get_space(bset)));
384
385 if (options->verify) {
386 copy = isl_basic_set_copy(bset);
387 context_copy = isl_basic_set_copy(context);
388 }
389
390 if (options->format == FORMAT_AFF) {
391 if (max)
392 pma = isl_basic_set_partial_lexmax_pw_multi_aff(bset,
393 context, &empty);
394 else
395 pma = isl_basic_set_partial_lexmin_pw_multi_aff(bset,
396 context, &empty);
397 } else {
398 if (max)
399 set = isl_basic_set_partial_lexmax(bset,
400 context, &empty);
401 else
402 set = isl_basic_set_partial_lexmin(bset,
403 context, &empty);
404 }
405
406 if (options->verify) {
407 assert(!rational);
408 if (options->format == FORMAT_AFF)
409 set = isl_set_from_pw_multi_aff(pma);
410 check_solution(copy, context_copy, set, empty, max);
411 isl_set_free(set);
412 } else {
413 isl_printer *p;
414 p = isl_printer_to_file(ctx, stdout);
415 if (options->format == FORMAT_AFF)
416 p = isl_printer_print_pw_multi_aff(p, pma);
417 else
418 p = isl_printer_print_set(p, set);
419 p = isl_printer_end_line(p);
420 p = isl_printer_print_str(p, "no solution: ");
421 p = isl_printer_print_set(p, empty);
422 p = isl_printer_end_line(p);
423 isl_printer_free(p);
424 isl_set_free(set);
425 isl_pw_multi_aff_free(pma);
426 }
427
428 isl_set_free(empty);
429 isl_ctx_free(ctx);
430
431 return 0;
432 }
433