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