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         unsigned 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         r = nparam >= 8 ? 4 : nparam >= 5 ? 6 : 30;
  75
  76         pt = isl_basic_set_sample_point(isl_basic_set_copy(bset));
  77         pt2 = isl_point_copy(pt);
  78
  79         for (i = 0; i < nparam; ++i) {
  80                 pt = isl_point_add_ui(pt, isl_dim_param, i, r);
  81                 pt2 = isl_point_sub_ui(pt2, isl_dim_param, i, r);
  82         }
  83
  84         box = isl_basic_set_box_from_points(pt, pt2);
  85
  86         return isl_basic_set_intersect(bset, box);
  87 }
  88
  89 static struct isl_basic_set *to_parameter_domain(struct isl_basic_set *context)
  90 {
  91         context = isl_basic_set_move_dims(context, isl_dim_param, 0,
  92                     isl_dim_set, 0, isl_basic_set_dim(context, isl_dim_set));
  93         context = isl_basic_set_params(context);
  94         return context;
  95 }
  96
  97 /* Plug in the initial values of "params" for the parameters in "bset" and
  98  * return the result.  The remaining entries in "params", if any,
  99  * correspond to the existentially quantified variables in the description
 100  * of the original context and can be ignored.
 101  */
 102 static __isl_give isl_basic_set *plug_in_parameters(
 103         __isl_take isl_basic_set *bset, __isl_take isl_vec *params)
 104 {
 105         int i, n;
 106
 107         n = isl_basic_set_dim(bset, isl_dim_param);
 108         for (i = 0; i < n; ++i)
 109                 bset = isl_basic_set_fix(bset,
 110                                          isl_dim_param, i, params->el[1 + i]);
 111
 112         bset = isl_basic_set_remove_dims(bset, isl_dim_param, 0, n);
 113
 114         isl_vec_free(params);
 115
 116         return bset;
 117 }
 118
 119 /* Plug in the initial values of "params" for the parameters in "set" and
 120  * return the result.  The remaining entries in "params", if any,
 121  * correspond to the existentially quantified variables in the description
 122  * of the original context and can be ignored.
 123  */
 124 static __isl_give isl_set *set_plug_in_parameters(__isl_take isl_set *set,
 125         __isl_take isl_vec *params)
 126 {
 127         int i, n;
 128
 129         n = isl_set_dim(set, isl_dim_param);
 130         for (i = 0; i < n; ++i)
 131                 set = isl_set_fix(set, isl_dim_param, i, params->el[1 + i]);
 132
 133         set = isl_set_remove_dims(set, isl_dim_param, 0, n);
 134
 135         isl_vec_free(params);
 136
 137         return set;
 138 }
 139
 140 /* Compute the lexicographically minimal (or maximal if max is set)
 141  * element of bset for the given values of the parameters, by
 142  * successively solving an ilp problem in each direction.
 143  */
 144 static __isl_give isl_vec *opt_at(__isl_take isl_basic_set *bset,
 145         __isl_take isl_vec *params, int max)
 146 {
 147         unsigned dim;
 148         isl_ctx *ctx;
 149         struct isl_vec *opt;
 150         struct isl_vec *obj;
 151         int i;
 152
 153         dim = isl_basic_set_dim(bset, isl_dim_set);
 154
 155         bset = plug_in_parameters(bset, params);
 156
 157         ctx = isl_basic_set_get_ctx(bset);
 158         if (isl_basic_set_plain_is_empty(bset)) {
 159                 opt = isl_vec_alloc(ctx, 0);
 160                 isl_basic_set_free(bset);
 161                 return opt;
 162         }
 163
 164         opt = isl_vec_alloc(ctx, 1 + dim);
 165         assert(opt);
 166
 167         obj = isl_vec_alloc(ctx, 1 + dim);
 168         assert(obj);
 169
 170         isl_int_set_si(opt->el[0], 1);
 171         isl_int_set_si(obj->el[0], 0);
 172
 173         for (i = 0; i < dim; ++i) {
 174                 enum isl_lp_result res;
 175
 176                 isl_seq_clr(obj->el + 1, dim);
 177                 isl_int_set_si(obj->el[1 + i], 1);
 178                 res = isl_basic_set_solve_ilp(bset, max, obj->el,
 179                                                 &opt->el[1 + i], NULL);
 180                 if (res == isl_lp_empty)
 181                         goto empty;
 182                 assert(res == isl_lp_ok);
 183                 bset = isl_basic_set_fix(bset, isl_dim_set, i, opt->el[1 + i]);
 184         }
 185
 186         isl_basic_set_free(bset);
 187         isl_vec_free(obj);
 188
 189         return opt;
 190 empty:
 191         isl_vec_free(opt);
 192         opt = isl_vec_alloc(ctx, 0);
 193         isl_basic_set_free(bset);
 194         isl_vec_free(obj);
 195
 196         return opt;
 197 }
 198
 199 struct isl_scan_pip {
 200         struct isl_scan_callback callback;
 201         isl_basic_set *bset;
 202         isl_set *sol;
 203         isl_set *empty;
 204         int stride;
 205         int n;
 206         int max;
 207 };
 208
 209 /* Check if the "manually" computed optimum of bset at the "sample"
 210  * values of the parameters agrees with the solution of pilp problem
 211  * represented by the pair (sol, empty).
 212  * In particular, if there is no solution for this value of the parameters,
 213  * then it should be an element of the parameter domain "empty".
 214  * Otherwise, the optimal solution, should be equal to the result of
 215  * plugging in the value of the parameters in "sol".
 216  */
 217 static isl_stat scan_one(struct isl_scan_callback *callback,
 218         __isl_take isl_vec *sample)
 219 {
 220         struct isl_scan_pip *sp = (struct isl_scan_pip *)callback;
 221         struct isl_vec *opt;
 222
 223         sp->n--;
 224
 225         opt = opt_at(isl_basic_set_copy(sp->bset), isl_vec_copy(sample), sp->max);
 226         assert(opt);
 227
 228         if (opt->size == 0) {
 229                 isl_point *sample_pnt;
 230                 sample_pnt = isl_point_alloc(isl_set_get_space(sp->empty), sample);
 231                 assert(isl_set_contains_point(sp->empty, sample_pnt));
 232                 isl_point_free(sample_pnt);
 233                 isl_vec_free(opt);
 234         } else {
 235                 isl_set *sol;
 236                 isl_set *opt_set;
 237                 opt_set = isl_set_from_basic_set(isl_basic_set_from_vec(opt));
 238                 sol = set_plug_in_parameters(isl_set_copy(sp->sol), sample);
 239                 assert(isl_set_is_equal(opt_set, sol));
 240                 isl_set_free(sol);
 241                 isl_set_free(opt_set);
 242         }
 243
 244         if (!(sp->n % sp->stride)) {
 245                 printf("o");
 246                 fflush(stdout);
 247         }
 248
 249         return sp->n >= 1 ? isl_stat_ok : isl_stat_error;
 250 }
 251
 252 static void check_solution(isl_basic_set *bset, isl_basic_set *context,
 253         isl_set *sol, isl_set *empty, int max)
 254 {
 255         struct isl_scan_pip sp;
 256         isl_int count, count_max;
 257         int i, n;
 258         int r;
 259
 260         context = set_bounds(context);
 261         context = isl_basic_set_underlying_set(context);
 262
 263         isl_int_init(count);
 264         isl_int_init(count_max);
 265
 266         isl_int_set_si(count_max, 2000);
 267         r = isl_basic_set_count_upto(context, count_max, &count);
 268         assert(r >= 0);
 269         n = isl_int_get_si(count);
 270
 271         isl_int_clear(count_max);
 272         isl_int_clear(count);
 273
 274         sp.callback.add = scan_one;
 275         sp.bset = bset;
 276         sp.sol = sol;
 277         sp.empty = empty;
 278         sp.n = n;
 279         sp.stride = n > 70 ? 1 + (n + 1)/70 : 1;
 280         sp.max = max;
 281
 282         for (i = 0; i < n; i += sp.stride)
 283                 printf(".");
 284         printf("\r");
 285         fflush(stdout);
 286
 287         isl_basic_set_scan(context, &sp.callback);
 288
 289         printf("\n");
 290
 291         isl_basic_set_free(bset);
 292 }
 293
 294 int main(int argc, char **argv)
 295 {
 296         struct isl_ctx *ctx;
 297         struct isl_basic_set *context, *bset, *copy, *context_copy;
 298         struct isl_set *set = NULL;
 299         struct isl_set *empty;
 300         isl_pw_multi_aff *pma = NULL;
 301         int neg_one;
 302         char s[1024];
 303         int urs_parms = 0;
 304         int urs_unknowns = 0;
 305         int max = 0;
 306         int rational = 0;
 307         int n;
 308         int nparam;
 309         struct options *options;
 310
 311         options = options_new_with_defaults();
 312         assert(options);
 313         argc = options_parse(options, argc, argv, ISL_ARG_ALL);
 314
 315         ctx = isl_ctx_alloc_with_options(&options_args, options);
 316
 317         context = isl_basic_set_read_from_file(ctx, stdin);
 318         assert(context);
 319         n = fscanf(stdin, "%d", &neg_one);
 320         assert(n == 1);
 321         assert(neg_one == -1);
 322         bset = isl_basic_set_read_from_file(ctx, stdin);
 323
 324         while (fgets(s, sizeof(s), stdin)) {
 325                 if (strncasecmp(s, "Maximize", 8) == 0)
 326                         max = 1;
 327                 if (strncasecmp(s, "Rational", 8) == 0) {
 328                         rational = 1;
 329                         bset = isl_basic_set_set_rational(bset);
 330                 }
 331                 if (strncasecmp(s, "Urs_parms", 9) == 0)
 332                         urs_parms = 1;
 333                 if (strncasecmp(s, "Urs_unknowns", 12) == 0)
 334                         urs_unknowns = 1;
 335         }
 336         if (!urs_parms)
 337                 context = isl_basic_set_intersect(context,
 338                 isl_basic_set_positive_orthant(isl_basic_set_get_space(context)));
 339         context = to_parameter_domain(context);
 340         nparam = isl_basic_set_dim(context, isl_dim_param);
 341         if (nparam != isl_basic_set_dim(bset, isl_dim_param)) {
 342                 int dim = isl_basic_set_dim(bset, isl_dim_set);
 343                 bset = isl_basic_set_move_dims(bset, isl_dim_param, 0,
 344                                             isl_dim_set, dim - nparam, nparam);
 345         }
 346         if (!urs_unknowns)
 347                 bset = isl_basic_set_intersect(bset,
 348                 isl_basic_set_positive_orthant(isl_basic_set_get_space(bset)));
 349
 350         if (options->verify) {
 351                 copy = isl_basic_set_copy(bset);
 352                 context_copy = isl_basic_set_copy(context);
 353         }
 354
 355         if (options->format == FORMAT_AFF) {
 356                 if (max)
 357                         pma = isl_basic_set_partial_lexmax_pw_multi_aff(bset,
 358                                                                 context, &empty);
 359                 else
 360                         pma = isl_basic_set_partial_lexmin_pw_multi_aff(bset,
 361                                                                 context, &empty);
 362         } else {
 363                 if (max)
 364                         set = isl_basic_set_partial_lexmax(bset,
 365                                                                 context, &empty);
 366                 else
 367                         set = isl_basic_set_partial_lexmin(bset,
 368                                                                 context, &empty);
 369         }
 370
 371         if (options->verify) {
 372                 assert(!rational);
 373                 if (options->format == FORMAT_AFF)
 374                         set = isl_set_from_pw_multi_aff(pma);
 375                 check_solution(copy, context_copy, set, empty, max);
 376                 isl_set_free(set);
 377         } else {
 378                 isl_printer *p;
 379                 p = isl_printer_to_file(ctx, stdout);
 380                 if (options->format == FORMAT_AFF)
 381                         p = isl_printer_print_pw_multi_aff(p, pma);
 382                 else
 383                         p = isl_printer_print_set(p, set);
 384                 p = isl_printer_end_line(p);
 385                 p = isl_printer_print_str(p, "no solution: ");
 386                 p = isl_printer_print_set(p, empty);
 387                 p = isl_printer_end_line(p);
 388                 isl_printer_free(p);
 389                 isl_set_free(set);
 390                 isl_pw_multi_aff_free(pma);
 391         }
 392
 393         isl_set_free(empty);
 394         isl_ctx_free(ctx);
 395
 396         return 0;
 397 }