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 __isl_give isl_basic_set *to_parameter_domain(
  90         __isl_take isl_basic_set *context)
  91 {
  92         context = isl_basic_set_move_dims(context, isl_dim_param, 0,
  93                     isl_dim_set, 0, isl_basic_set_dim(context, isl_dim_set));
  94         context = isl_basic_set_params(context);
  95         return context;
  96 }
  97
  98 /* Plug in the initial values of "params" for the parameters in "bset" and
  99  * return the result.  The remaining entries in "params", if any,
 100  * correspond to the existentially quantified variables in the description
 101  * of the original context and can be ignored.
 102  */
 103 static __isl_give isl_basic_set *plug_in_parameters(
 104         __isl_take isl_basic_set *bset, __isl_take isl_vec *params)
 105 {
 106         int i, n;
 107
 108         n = isl_basic_set_dim(bset, isl_dim_param);
 109         for (i = 0; i < n; ++i)
 110                 bset = isl_basic_set_fix(bset,
 111                                          isl_dim_param, i, params->el[1 + i]);
 112
 113         bset = isl_basic_set_remove_dims(bset, isl_dim_param, 0, n);
 114
 115         isl_vec_free(params);
 116
 117         return bset;
 118 }
 119
 120 /* Plug in the initial values of "params" for the parameters in "set" and
 121  * return the result.  The remaining entries in "params", if any,
 122  * correspond to the existentially quantified variables in the description
 123  * of the original context and can be ignored.
 124  */
 125 static __isl_give isl_set *set_plug_in_parameters(__isl_take isl_set *set,
 126         __isl_take isl_vec *params)
 127 {
 128         int i, n;
 129
 130         n = isl_set_dim(set, isl_dim_param);
 131         for (i = 0; i < n; ++i)
 132                 set = isl_set_fix(set, isl_dim_param, i, params->el[1 + i]);
 133
 134         set = isl_set_remove_dims(set, isl_dim_param, 0, n);
 135
 136         isl_vec_free(params);
 137
 138         return set;
 139 }
 140
 141 /* Compute the lexicographically minimal (or maximal if max is set)
 142  * element of bset for the given values of the parameters, by
 143  * successively solving an ilp problem in each direction.
 144  */
 145 static __isl_give isl_vec *opt_at(__isl_take isl_basic_set *bset,
 146         __isl_take isl_vec *params, int max)
 147 {
 148         unsigned dim;
 149         isl_ctx *ctx;
 150         struct isl_vec *opt;
 151         struct isl_vec *obj;
 152         int i;
 153
 154         dim = isl_basic_set_dim(bset, isl_dim_set);
 155
 156         bset = plug_in_parameters(bset, params);
 157
 158         ctx = isl_basic_set_get_ctx(bset);
 159         if (isl_basic_set_plain_is_empty(bset)) {
 160                 opt = isl_vec_alloc(ctx, 0);
 161                 isl_basic_set_free(bset);
 162                 return opt;
 163         }
 164
 165         opt = isl_vec_alloc(ctx, 1 + dim);
 166         assert(opt);
 167
 168         obj = isl_vec_alloc(ctx, 1 + dim);
 169         assert(obj);
 170
 171         isl_int_set_si(opt->el[0], 1);
 172         isl_int_set_si(obj->el[0], 0);
 173
 174         for (i = 0; i < dim; ++i) {
 175                 enum isl_lp_result res;
 176
 177                 isl_seq_clr(obj->el + 1, dim);
 178                 isl_int_set_si(obj->el[1 + i], 1);
 179                 res = isl_basic_set_solve_ilp(bset, max, obj->el,
 180                                                 &opt->el[1 + i], NULL);
 181                 if (res == isl_lp_empty)
 182                         goto empty;
 183                 assert(res == isl_lp_ok);
 184                 bset = isl_basic_set_fix(bset, isl_dim_set, i, opt->el[1 + i]);
 185         }
 186
 187         isl_basic_set_free(bset);
 188         isl_vec_free(obj);
 189
 190         return opt;
 191 empty:
 192         isl_vec_free(opt);
 193         opt = isl_vec_alloc(ctx, 0);
 194         isl_basic_set_free(bset);
 195         isl_vec_free(obj);
 196
 197         return opt;
 198 }
 199
 200 struct isl_scan_pip {
 201         struct isl_scan_callback callback;
 202         isl_basic_set *bset;
 203         isl_set *sol;
 204         isl_set *empty;
 205         int stride;
 206         int n;
 207         int max;
 208 };
 209
 210 /* Check if the "manually" computed optimum of bset at the "sample"
 211  * values of the parameters agrees with the solution of pilp problem
 212  * represented by the pair (sol, empty).
 213  * In particular, if there is no solution for this value of the parameters,
 214  * then it should be an element of the parameter domain "empty".
 215  * Otherwise, the optimal solution, should be equal to the result of
 216  * plugging in the value of the parameters in "sol".
 217  */
 218 static isl_stat scan_one(struct isl_scan_callback *callback,
 219         __isl_take isl_vec *sample)
 220 {
 221         struct isl_scan_pip *sp = (struct isl_scan_pip *)callback;
 222         struct isl_vec *opt;
 223
 224         sp->n--;
 225
 226         opt = opt_at(isl_basic_set_copy(sp->bset), isl_vec_copy(sample), sp->max);
 227         assert(opt);
 228
 229         if (opt->size == 0) {
 230                 isl_point *sample_pnt;
 231                 sample_pnt = isl_point_alloc(isl_set_get_space(sp->empty), sample);
 232                 assert(isl_set_contains_point(sp->empty, sample_pnt));
 233                 isl_point_free(sample_pnt);
 234                 isl_vec_free(opt);
 235         } else {
 236                 isl_set *sol;
 237                 isl_set *opt_set;
 238                 opt_set = isl_set_from_basic_set(isl_basic_set_from_vec(opt));
 239                 sol = set_plug_in_parameters(isl_set_copy(sp->sol), sample);
 240                 assert(isl_set_is_equal(opt_set, sol));
 241                 isl_set_free(sol);
 242                 isl_set_free(opt_set);
 243         }
 244
 245         if (!(sp->n % sp->stride)) {
 246                 printf("o");
 247                 fflush(stdout);
 248         }
 249
 250         return sp->n >= 1 ? isl_stat_ok : isl_stat_error;
 251 }
 252
 253 static void check_solution(isl_basic_set *bset, isl_basic_set *context,
 254         isl_set *sol, isl_set *empty, int max)
 255 {
 256         struct isl_scan_pip sp;
 257         isl_int count, count_max;
 258         int i, n;
 259         int r;
 260
 261         context = set_bounds(context);
 262         context = isl_basic_set_underlying_set(context);
 263
 264         isl_int_init(count);
 265         isl_int_init(count_max);
 266
 267         isl_int_set_si(count_max, 2000);
 268         r = isl_basic_set_count_upto(context, count_max, &count);
 269         assert(r >= 0);
 270         n = isl_int_get_si(count);
 271
 272         isl_int_clear(count_max);
 273         isl_int_clear(count);
 274
 275         sp.callback.add = scan_one;
 276         sp.bset = bset;
 277         sp.sol = sol;
 278         sp.empty = empty;
 279         sp.n = n;
 280         sp.stride = n > 70 ? 1 + (n + 1)/70 : 1;
 281         sp.max = max;
 282
 283         for (i = 0; i < n; i += sp.stride)
 284                 printf(".");
 285         printf("\r");
 286         fflush(stdout);
 287
 288         isl_basic_set_scan(context, &sp.callback);
 289
 290         printf("\n");
 291
 292         isl_basic_set_free(bset);
 293 }
 294
 295 int main(int argc, char **argv)
 296 {
 297         struct isl_ctx *ctx;
 298         struct isl_basic_set *context, *bset, *copy, *context_copy;
 299         struct isl_set *set = NULL;
 300         struct isl_set *empty;
 301         isl_pw_multi_aff *pma = NULL;
 302         int neg_one;
 303         char s[1024];
 304         int urs_parms = 0;
 305         int urs_unknowns = 0;
 306         int max = 0;
 307         int rational = 0;
 308         int n;
 309         int nparam;
 310         struct options *options;
 311
 312         options = options_new_with_defaults();
 313         assert(options);
 314         argc = options_parse(options, argc, argv, ISL_ARG_ALL);
 315
 316         ctx = isl_ctx_alloc_with_options(&options_args, options);
 317
 318         context = isl_basic_set_read_from_file(ctx, stdin);
 319         assert(context);
 320         n = fscanf(stdin, "%d", &neg_one);
 321         assert(n == 1);
 322         assert(neg_one == -1);
 323         bset = isl_basic_set_read_from_file(ctx, stdin);
 324
 325         while (fgets(s, sizeof(s), stdin)) {
 326                 if (strncasecmp(s, "Maximize", 8) == 0)
 327                         max = 1;
 328                 if (strncasecmp(s, "Rational", 8) == 0) {
 329                         rational = 1;
 330                         bset = isl_basic_set_set_rational(bset);
 331                 }
 332                 if (strncasecmp(s, "Urs_parms", 9) == 0)
 333                         urs_parms = 1;
 334                 if (strncasecmp(s, "Urs_unknowns", 12) == 0)
 335                         urs_unknowns = 1;
 336         }
 337         if (!urs_parms)
 338                 context = isl_basic_set_intersect(context,
 339                 isl_basic_set_positive_orthant(isl_basic_set_get_space(context)));
 340         context = to_parameter_domain(context);
 341         nparam = isl_basic_set_dim(context, isl_dim_param);
 342         if (nparam != isl_basic_set_dim(bset, isl_dim_param)) {
 343                 int dim = isl_basic_set_dim(bset, isl_dim_set);
 344                 bset = isl_basic_set_move_dims(bset, isl_dim_param, 0,
 345                                             isl_dim_set, dim - nparam, nparam);
 346         }
 347         if (!urs_unknowns)
 348                 bset = isl_basic_set_intersect(bset,
 349                 isl_basic_set_positive_orthant(isl_basic_set_get_space(bset)));
 350
 351         if (options->verify) {
 352                 copy = isl_basic_set_copy(bset);
 353                 context_copy = isl_basic_set_copy(context);
 354         }
 355
 356         if (options->format == FORMAT_AFF) {
 357                 if (max)
 358                         pma = isl_basic_set_partial_lexmax_pw_multi_aff(bset,
 359                                                                 context, &empty);
 360                 else
 361                         pma = isl_basic_set_partial_lexmin_pw_multi_aff(bset,
 362                                                                 context, &empty);
 363         } else {
 364                 if (max)
 365                         set = isl_basic_set_partial_lexmax(bset,
 366                                                                 context, &empty);
 367                 else
 368                         set = isl_basic_set_partial_lexmin(bset,
 369                                                                 context, &empty);
 370         }
 371
 372         if (options->verify) {
 373                 assert(!rational);
 374                 if (options->format == FORMAT_AFF)
 375                         set = isl_set_from_pw_multi_aff(pma);
 376                 check_solution(copy, context_copy, set, empty, max);
 377                 isl_set_free(set);
 378         } else {
 379                 isl_printer *p;
 380                 p = isl_printer_to_file(ctx, stdout);
 381                 if (options->format == FORMAT_AFF)
 382                         p = isl_printer_print_pw_multi_aff(p, pma);
 383                 else
 384                         p = isl_printer_print_set(p, set);
 385                 p = isl_printer_end_line(p);
 386                 p = isl_printer_print_str(p, "no solution: ");
 387                 p = isl_printer_print_set(p, empty);
 388                 p = isl_printer_end_line(p);
 389                 isl_printer_free(p);
 390                 isl_set_free(set);
 391                 isl_pw_multi_aff_free(pma);
 392         }
 393
 394         isl_set_free(empty);
 395         isl_ctx_free(ctx);
 396
 397         return 0;
 398 }