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 <strings.h>
  13 #include <isl_map_private.h>
  14 #include <isl/aff.h>
  15 #include <isl/set.h>
  16 #include "isl_tab.h"
  17 #include "isl_sample.h"
  18 #include "isl_scan.h"
  19 #include <isl/seq.h>
  20 #include <isl/ilp.h>
  21 #include <isl/printer.h>
  22 #include <isl_point_private.h>
  23 #include <isl/options.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
  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         unsigned 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         r = nparam >= 8 ? 4 : nparam >= 5 ? 6 : 30;
  74
  75         pt = isl_basic_set_sample_point(isl_basic_set_copy(bset));
  76         pt2 = isl_point_copy(pt);
  77
  78         for (i = 0; i < nparam; ++i) {
  79                 pt = isl_point_add_ui(pt, isl_dim_param, i, r);
  80                 pt2 = isl_point_sub_ui(pt2, isl_dim_param, i, r);
  81         }
  82
  83         box = isl_basic_set_box_from_points(pt, pt2);
  84
  85         return isl_basic_set_intersect(bset, box);
  86 }
  87
  88 static struct isl_basic_set *to_parameter_domain(struct isl_basic_set *context)
  89 {
  90         context = isl_basic_set_move_dims(context, isl_dim_param, 0,
  91                     isl_dim_set, 0, isl_basic_set_dim(context, isl_dim_set));
  92         context = isl_basic_set_params(context);
  93         return context;
  94 }
  95
  96 isl_basic_set *plug_in_parameters(isl_basic_set *bset, struct isl_vec *params)
  97 {
  98         int i;
  99
 100         for (i = 0; i < params->size - 1; ++i)
 101                 bset = isl_basic_set_fix(bset,
 102                                          isl_dim_param, i, params->el[1 + i]);
 103
 104         bset = isl_basic_set_remove_dims(bset,
 105                                          isl_dim_param, 0, params->size - 1);
 106
 107         isl_vec_free(params);
 108
 109         return bset;
 110 }
 111
 112 isl_set *set_plug_in_parameters(isl_set *set, struct isl_vec *params)
 113 {
 114         int i;
 115
 116         for (i = 0; i < params->size - 1; ++i)
 117                 set = isl_set_fix(set, isl_dim_param, i, params->el[1 + i]);
 118
 119         set = isl_set_remove_dims(set, isl_dim_param, 0, params->size - 1);
 120
 121         isl_vec_free(params);
 122
 123         return set;
 124 }
 125
 126 /* Compute the lexicographically minimal (or maximal if max is set)
 127  * element of bset for the given values of the parameters, by
 128  * successively solving an ilp problem in each direction.
 129  */
 130 struct isl_vec *opt_at(struct isl_basic_set *bset,
 131         struct isl_vec *params, int max)
 132 {
 133         unsigned dim;
 134         struct isl_vec *opt;
 135         struct isl_vec *obj;
 136         int i;
 137
 138         dim = isl_basic_set_dim(bset, isl_dim_set);
 139
 140         bset = plug_in_parameters(bset, params);
 141
 142         if (isl_basic_set_plain_is_empty(bset)) {
 143                 opt = isl_vec_alloc(bset->ctx, 0);
 144                 isl_basic_set_free(bset);
 145                 return opt;
 146         }
 147
 148         opt = isl_vec_alloc(bset->ctx, 1 + dim);
 149         assert(opt);
 150
 151         obj = isl_vec_alloc(bset->ctx, 1 + dim);
 152         assert(obj);
 153
 154         isl_int_set_si(opt->el[0], 1);
 155         isl_int_set_si(obj->el[0], 0);
 156
 157         for (i = 0; i < dim; ++i) {
 158                 enum isl_lp_result res;
 159
 160                 isl_seq_clr(obj->el + 1, dim);
 161                 isl_int_set_si(obj->el[1 + i], 1);
 162                 res = isl_basic_set_solve_ilp(bset, max, obj->el,
 163                                                 &opt->el[1 + i], NULL);
 164                 if (res == isl_lp_empty)
 165                         goto empty;
 166                 assert(res == isl_lp_ok);
 167                 bset = isl_basic_set_fix(bset, isl_dim_set, i, opt->el[1 + i]);
 168         }
 169
 170         isl_basic_set_free(bset);
 171         isl_vec_free(obj);
 172
 173         return opt;
 174 empty:
 175         isl_vec_free(opt);
 176         opt = isl_vec_alloc(bset->ctx, 0);
 177         isl_basic_set_free(bset);
 178         isl_vec_free(obj);
 179
 180         return opt;
 181 }
 182
 183 struct isl_scan_pip {
 184         struct isl_scan_callback callback;
 185         isl_basic_set *bset;
 186         isl_set *sol;
 187         isl_set *empty;
 188         int stride;
 189         int n;
 190         int max;
 191 };
 192
 193 /* Check if the "manually" computed optimum of bset at the "sample"
 194  * values of the parameters agrees with the solution of pilp problem
 195  * represented by the pair (sol, empty).
 196  * In particular, if there is no solution for this value of the parameters,
 197  * then it should be an element of the parameter domain "empty".
 198  * Otherwise, the optimal solution, should be equal to the result of
 199  * plugging in the value of the parameters in "sol".
 200  */
 201 static int scan_one(struct isl_scan_callback *callback,
 202         __isl_take isl_vec *sample)
 203 {
 204         struct isl_scan_pip *sp = (struct isl_scan_pip *)callback;
 205         struct isl_vec *opt;
 206
 207         sp->n--;
 208
 209         opt = opt_at(isl_basic_set_copy(sp->bset), isl_vec_copy(sample), sp->max);
 210         assert(opt);
 211
 212         if (opt->size == 0) {
 213                 isl_point *sample_pnt;
 214                 sample_pnt = isl_point_alloc(isl_set_get_space(sp->empty), sample);
 215                 assert(isl_set_contains_point(sp->empty, sample_pnt));
 216                 isl_point_free(sample_pnt);
 217                 isl_vec_free(opt);
 218         } else {
 219                 isl_set *sol;
 220                 isl_set *opt_set;
 221                 opt_set = isl_set_from_basic_set(isl_basic_set_from_vec(opt));
 222                 sol = set_plug_in_parameters(isl_set_copy(sp->sol), sample);
 223                 assert(isl_set_is_equal(opt_set, sol));
 224                 isl_set_free(sol);
 225                 isl_set_free(opt_set);
 226         }
 227
 228         if (!(sp->n % sp->stride)) {
 229                 printf("o");
 230                 fflush(stdout);
 231         }
 232
 233         return sp->n >= 1 ? 0 : -1;
 234 }
 235
 236 static void check_solution(isl_basic_set *bset, isl_basic_set *context,
 237         isl_set *sol, isl_set *empty, int max)
 238 {
 239         struct isl_scan_pip sp;
 240         isl_int count, count_max;
 241         int i, n;
 242         int r;
 243
 244         context = set_bounds(context);
 245         context = isl_basic_set_underlying_set(context);
 246
 247         isl_int_init(count);
 248         isl_int_init(count_max);
 249
 250         isl_int_set_si(count_max, 2000);
 251         r = isl_basic_set_count_upto(context, count_max, &count);
 252         assert(r >= 0);
 253         n = isl_int_get_si(count);
 254
 255         isl_int_clear(count_max);
 256         isl_int_clear(count);
 257
 258         sp.callback.add = scan_one;
 259         sp.bset = bset;
 260         sp.sol = sol;
 261         sp.empty = empty;
 262         sp.n = n;
 263         sp.stride = n > 70 ? 1 + (n + 1)/70 : 1;
 264         sp.max = max;
 265
 266         for (i = 0; i < n; i += sp.stride)
 267                 printf(".");
 268         printf("\r");
 269         fflush(stdout);
 270
 271         isl_basic_set_scan(context, &sp.callback);
 272
 273         printf("\n");
 274
 275         isl_basic_set_free(bset);
 276 }
 277
 278 int main(int argc, char **argv)
 279 {
 280         struct isl_ctx *ctx;
 281         struct isl_basic_set *context, *bset, *copy, *context_copy;
 282         struct isl_set *set = NULL;
 283         struct isl_set *empty;
 284         isl_pw_multi_aff *pma = NULL;
 285         int neg_one;
 286         char s[1024];
 287         int urs_parms = 0;
 288         int urs_unknowns = 0;
 289         int max = 0;
 290         int rational = 0;
 291         int n;
 292         int nparam;
 293         struct options *options;
 294
 295         options = options_new_with_defaults();
 296         assert(options);
 297         argc = options_parse(options, argc, argv, ISL_ARG_ALL);
 298
 299         ctx = isl_ctx_alloc_with_options(&options_args, options);
 300
 301         context = isl_basic_set_read_from_file(ctx, stdin);
 302         assert(context);
 303         n = fscanf(stdin, "%d", &neg_one);
 304         assert(n == 1);
 305         assert(neg_one == -1);
 306         bset = isl_basic_set_read_from_file(ctx, stdin);
 307
 308         while (fgets(s, sizeof(s), stdin)) {
 309                 if (strncasecmp(s, "Maximize", 8) == 0)
 310                         max = 1;
 311                 if (strncasecmp(s, "Rational", 8) == 0) {
 312                         rational = 1;
 313                         bset = isl_basic_set_set_rational(bset);
 314                 }
 315                 if (strncasecmp(s, "Urs_parms", 9) == 0)
 316                         urs_parms = 1;
 317                 if (strncasecmp(s, "Urs_unknowns", 12) == 0)
 318                         urs_unknowns = 1;
 319         }
 320         if (!urs_parms)
 321                 context = isl_basic_set_intersect(context,
 322                 isl_basic_set_positive_orthant(isl_basic_set_get_space(context)));
 323         context = to_parameter_domain(context);
 324         nparam = isl_basic_set_dim(context, isl_dim_param);
 325         if (nparam != isl_basic_set_dim(bset, isl_dim_param)) {
 326                 int dim = isl_basic_set_dim(bset, isl_dim_set);
 327                 bset = isl_basic_set_move_dims(bset, isl_dim_param, 0,
 328                                             isl_dim_set, dim - nparam, nparam);
 329         }
 330         if (!urs_unknowns)
 331                 bset = isl_basic_set_intersect(bset,
 332                 isl_basic_set_positive_orthant(isl_basic_set_get_space(bset)));
 333
 334         if (options->verify) {
 335                 copy = isl_basic_set_copy(bset);
 336                 context_copy = isl_basic_set_copy(context);
 337         }
 338
 339         if (options->format == FORMAT_AFF) {
 340                 if (max)
 341                         pma = isl_basic_set_partial_lexmax_pw_multi_aff(bset,
 342                                                                 context, &empty);
 343                 else
 344                         pma = isl_basic_set_partial_lexmin_pw_multi_aff(bset,
 345                                                                 context, &empty);
 346         } else {
 347                 if (max)
 348                         set = isl_basic_set_partial_lexmax(bset,
 349                                                                 context, &empty);
 350                 else
 351                         set = isl_basic_set_partial_lexmin(bset,
 352                                                                 context, &empty);
 353         }
 354
 355         if (options->verify) {
 356                 assert(!rational);
 357                 if (options->format == FORMAT_AFF)
 358                         set = isl_set_from_pw_multi_aff(pma);
 359                 check_solution(copy, context_copy, set, empty, max);
 360                 isl_set_free(set);
 361         } else {
 362                 isl_printer *p;
 363                 p = isl_printer_to_file(ctx, stdout);
 364                 if (options->format == FORMAT_AFF)
 365                         p = isl_printer_print_pw_multi_aff(p, pma);
 366                 else
 367                         p = isl_printer_print_set(p, set);
 368                 p = isl_printer_end_line(p);
 369                 p = isl_printer_print_str(p, "no solution: ");
 370                 p = isl_printer_print_set(p, empty);
 371                 p = isl_printer_end_line(p);
 372                 isl_printer_free(p);
 373                 isl_set_free(set);
 374                 isl_pw_multi_aff_free(pma);
 375         }
 376
 377         isl_set_free(empty);
 378         isl_ctx_free(ctx);
 379
 380         return 0;
 381 }