pip.c

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