isl_bound.c

   1 /*
   2  * Copyright 2010      INRIA Saclay
   3  *
   4  * Use of this software is governed by the GNU LGPLv2.1 license
   5  *
   6  * Written by Sven Verdoolaege, INRIA Saclay - Ile-de-France,
   7  * Parc Club Orsay Universite, ZAC des vignes, 4 rue Jacques Monod,
   8  * 91893 Orsay, France
   9  */
  10
  11 #include <isl_map_private.h>
  12 #include <isl_bound.h>
  13 #include <isl_bernstein.h>
  14 #include <isl_range.h>
  15 #include <isl_polynomial_private.h>
  16
  17 /* Compute a bound on the polynomial defined over the parametric polytope
  18  * using either range propagation or bernstein expansion and
  19  * store the result in bound->pwf and bound->pwf_tight.
  20  * Since bernstein expansion requires bounded domains, we apply
  21  * range propagation on unbounded domains.  Otherwise, we respect the choice
  22  * of the user.
  23  */
  24 static int compressed_guarded_poly_bound(__isl_take isl_basic_set *bset,
  25         __isl_take isl_qpolynomial *poly, void *user)
  26 {
  27         struct isl_bound *bound = (struct isl_bound *)user;
  28         int bounded;
  29
  30         if (!bset || !poly)
  31                 goto error;
  32
  33         if (bset->ctx->opt->bound == ISL_BOUND_RANGE)
  34                 return isl_qpolynomial_bound_on_domain_range(bset, poly, bound);
  35
  36         bounded = isl_basic_set_is_bounded(bset);
  37         if (bounded < 0)
  38                 goto error;
  39         if (bounded)
  40                 return isl_qpolynomial_bound_on_domain_bernstein(bset, poly, bound);
  41         else
  42                 return isl_qpolynomial_bound_on_domain_range(bset, poly, bound);
  43 error:
  44         isl_basic_set_free(bset);
  45         isl_qpolynomial_free(poly);
  46         return -1;
  47 }
  48
  49 static int unwrapped_guarded_poly_bound(__isl_take isl_basic_set *bset,
  50         __isl_take isl_qpolynomial *poly, void *user)
  51 {
  52         struct isl_bound *bound = (struct isl_bound *)user;
  53         isl_pw_qpolynomial_fold *top_pwf;
  54         isl_pw_qpolynomial_fold *top_pwf_tight;
  55         isl_dim *dim;
  56         isl_morph *morph;
  57         unsigned orig_nvar, final_nvar;
  58         int r;
  59
  60         bset = isl_basic_set_detect_equalities(bset);
  61
  62         if (!bset)
  63                 goto error;
  64
  65         if (bset->n_eq == 0)
  66                 return compressed_guarded_poly_bound(bset, poly, user);
  67
  68         orig_nvar = isl_basic_set_dim(bset, isl_dim_set);
  69
  70         morph = isl_basic_set_full_compression(bset);
  71
  72         bset = isl_morph_basic_set(isl_morph_copy(morph), bset);
  73         poly = isl_qpolynomial_morph(poly, isl_morph_copy(morph));
  74
  75         final_nvar = isl_basic_set_dim(bset, isl_dim_set);
  76
  77         dim = isl_morph_get_ran_dim(morph);
  78         dim = isl_dim_drop(dim, isl_dim_set, 0, isl_dim_size(dim, isl_dim_set));
  79
  80         top_pwf = bound->pwf;
  81         top_pwf_tight = bound->pwf_tight;
  82
  83         bound->pwf = isl_pw_qpolynomial_fold_zero(isl_dim_copy(dim),
  84                                                   bound->type);
  85         bound->pwf_tight = isl_pw_qpolynomial_fold_zero(dim, bound->type);
  86
  87         r = compressed_guarded_poly_bound(bset, poly, user);
  88
  89         morph = isl_morph_remove_dom_dims(morph, isl_dim_set, 0, orig_nvar);
  90         morph = isl_morph_remove_ran_dims(morph, isl_dim_set, 0, final_nvar);
  91         morph = isl_morph_inverse(morph);
  92
  93         bound->pwf = isl_pw_qpolynomial_fold_morph(bound->pwf,
  94                                                         isl_morph_copy(morph));
  95         bound->pwf_tight = isl_pw_qpolynomial_fold_morph(bound->pwf_tight, morph);
  96
  97         bound->pwf = isl_pw_qpolynomial_fold_fold(top_pwf, bound->pwf);
  98         bound->pwf_tight = isl_pw_qpolynomial_fold_fold(top_pwf_tight,
  99                                                         bound->pwf_tight);
 100
 101         return r;
 102 error:
 103         isl_basic_set_free(bset);
 104         isl_qpolynomial_free(poly);
 105         return -1;
 106 }
 107
 108 static int guarded_poly_bound(__isl_take isl_basic_set *bset,
 109         __isl_take isl_qpolynomial *poly, void *user)
 110 {
 111         struct isl_bound *bound = (struct isl_bound *)user;
 112         isl_dim *dim;
 113         isl_pw_qpolynomial_fold *top_pwf;
 114         isl_pw_qpolynomial_fold *top_pwf_tight;
 115         int nparam;
 116         int n_in;
 117         int r;
 118
 119         if (!bound->wrapping)
 120                 return unwrapped_guarded_poly_bound(bset, poly, user);
 121
 122         nparam = isl_dim_size(bound->dim, isl_dim_param);
 123         n_in = isl_dim_size(bound->dim, isl_dim_set);
 124
 125         bset = isl_basic_set_move_dims(bset, isl_dim_param, nparam,
 126                                         isl_dim_set, 0, n_in);
 127         poly = isl_qpolynomial_move_dims(poly, isl_dim_param, nparam,
 128                                         isl_dim_set, 0, n_in);
 129
 130         dim = isl_basic_set_get_dim(bset);
 131         dim = isl_dim_drop(dim, isl_dim_set, 0, isl_dim_size(dim, isl_dim_set));
 132
 133         top_pwf = bound->pwf;
 134         top_pwf_tight = bound->pwf_tight;
 135
 136         bound->pwf = isl_pw_qpolynomial_fold_zero(isl_dim_copy(dim),
 137                                                   bound->type);
 138         bound->pwf_tight = isl_pw_qpolynomial_fold_zero(dim, bound->type);
 139
 140         r = unwrapped_guarded_poly_bound(bset, poly, user);
 141
 142         bound->pwf = isl_pw_qpolynomial_fold_reset_dim(bound->pwf,
 143                                                     isl_dim_copy(bound->dim));
 144         bound->pwf_tight = isl_pw_qpolynomial_fold_reset_dim(bound->pwf_tight,
 145                                                     isl_dim_copy(bound->dim));
 146
 147         bound->pwf = isl_pw_qpolynomial_fold_fold(top_pwf, bound->pwf);
 148         bound->pwf_tight = isl_pw_qpolynomial_fold_fold(top_pwf_tight,
 149                                                         bound->pwf_tight);
 150
 151         return r;
 152 }
 153
 154 static int guarded_qp(__isl_take isl_qpolynomial *qp, void *user)
 155 {
 156         struct isl_bound *bound = (struct isl_bound *)user;
 157         int r;
 158
 159         r = isl_qpolynomial_as_polynomial_on_domain(qp, bound->bset,
 160                                                     &guarded_poly_bound, user);
 161         isl_qpolynomial_free(qp);
 162         return r;
 163 }
 164
 165 static int basic_guarded_fold(__isl_take isl_basic_set *bset, void *user)
 166 {
 167         struct isl_bound *bound = (struct isl_bound *)user;
 168         int r;
 169
 170         bound->bset = bset;
 171         r = isl_qpolynomial_fold_foreach_qpolynomial(bound->fold,
 172                                                         &guarded_qp, user);
 173         isl_basic_set_free(bset);
 174         return r;
 175 }
 176
 177 static int guarded_fold(__isl_take isl_set *set,
 178         __isl_take isl_qpolynomial_fold *fold, void *user)
 179 {
 180         struct isl_bound *bound = (struct isl_bound *)user;
 181
 182         if (!set || !fold)
 183                 goto error;
 184
 185         set = isl_set_make_disjoint(set);
 186
 187         bound->fold = fold;
 188         bound->type = isl_qpolynomial_fold_get_type(fold);
 189
 190         if (isl_set_foreach_basic_set(set, &basic_guarded_fold, bound) < 0)
 191                 goto error;
 192
 193         isl_set_free(set);
 194         isl_qpolynomial_fold_free(fold);
 195
 196         return 0;
 197 error:
 198         isl_set_free(set);
 199         isl_qpolynomial_fold_free(fold);
 200         return -1;
 201 }
 202
 203 __isl_give isl_pw_qpolynomial_fold *isl_pw_qpolynomial_fold_bound(
 204         __isl_take isl_pw_qpolynomial_fold *pwf, int *tight)
 205 {
 206         unsigned nvar;
 207         struct isl_bound bound;
 208         int covers;
 209
 210         if (!pwf)
 211                 return NULL;
 212
 213         bound.dim = isl_pw_qpolynomial_fold_get_dim(pwf);
 214         nvar = isl_dim_size(bound.dim, isl_dim_set);
 215
 216         bound.wrapping = isl_dim_is_wrapping(bound.dim);
 217         if (bound.wrapping) {
 218                 bound.dim = isl_dim_unwrap(bound.dim);
 219                 nvar = isl_dim_size(bound.dim, isl_dim_out);
 220                 bound.dim = isl_dim_domain(bound.dim);
 221         } else
 222                 bound.dim = isl_dim_drop(bound.dim, isl_dim_set, 0, nvar);
 223
 224         if (nvar == 0) {
 225                 if (tight)
 226                         *tight = 1;
 227                 return isl_pw_qpolynomial_fold_reset_dim(pwf, bound.dim);
 228         }
 229
 230         if (isl_pw_qpolynomial_fold_is_zero(pwf)) {
 231                 enum isl_fold type = pwf->type;
 232                 isl_pw_qpolynomial_fold_free(pwf);
 233                 if (tight)
 234                         *tight = 1;
 235                 return isl_pw_qpolynomial_fold_zero(bound.dim, type);
 236         }
 237
 238         bound.pwf = isl_pw_qpolynomial_fold_zero(isl_dim_copy(bound.dim),
 239                                                         pwf->type);
 240         bound.pwf_tight = isl_pw_qpolynomial_fold_zero(isl_dim_copy(bound.dim),
 241                                                         pwf->type);
 242         bound.check_tight = !!tight;
 243
 244         if (isl_pw_qpolynomial_fold_foreach_lifted_piece(pwf,
 245                                                         guarded_fold, &bound) < 0)
 246                 goto error;
 247
 248         covers = isl_pw_qpolynomial_fold_covers(bound.pwf_tight, bound.pwf);
 249         if (covers < 0)
 250                 goto error;
 251
 252         if (tight)
 253                 *tight = covers;
 254
 255         isl_dim_free(bound.dim);
 256         isl_pw_qpolynomial_fold_free(pwf);
 257
 258         if (covers) {
 259                 isl_pw_qpolynomial_fold_free(bound.pwf);
 260                 return bound.pwf_tight;
 261         }
 262
 263         bound.pwf = isl_pw_qpolynomial_fold_fold(bound.pwf, bound.pwf_tight);
 264
 265         return bound.pwf;
 266 error:
 267         isl_pw_qpolynomial_fold_free(bound.pwf_tight);
 268         isl_pw_qpolynomial_fold_free(bound.pwf);
 269         isl_pw_qpolynomial_fold_free(pwf);
 270         isl_dim_free(bound.dim);
 271         return NULL;
 272 }
 273
 274 __isl_give isl_pw_qpolynomial_fold *isl_pw_qpolynomial_bound(
 275         __isl_take isl_pw_qpolynomial *pwqp, enum isl_fold type, int *tight)
 276 {
 277         isl_pw_qpolynomial_fold *pwf;
 278
 279         pwf = isl_pw_qpolynomial_fold_from_pw_qpolynomial(type, pwqp);
 280         return isl_pw_qpolynomial_fold_bound(pwf, tight);
 281 }
 282
 283 struct isl_union_bound_data {
 284         enum isl_fold type;
 285         int tight;
 286         isl_union_pw_qpolynomial_fold *res;
 287 };
 288
 289 static int bound_pw(__isl_take isl_pw_qpolynomial *pwqp, void *user)
 290 {
 291         struct isl_union_bound_data *data = user;
 292         isl_pw_qpolynomial_fold *pwf;
 293
 294         pwf = isl_pw_qpolynomial_bound(pwqp, data->type,
 295                                         data->tight ? &data->tight : NULL);
 296         data->res = isl_union_pw_qpolynomial_fold_fold_pw_qpolynomial_fold(
 297                                                                 data->res, pwf);
 298
 299         return 0;
 300 }
 301
 302 __isl_give isl_union_pw_qpolynomial_fold *isl_union_pw_qpolynomial_bound(
 303         __isl_take isl_union_pw_qpolynomial *upwqp,
 304         enum isl_fold type, int *tight)
 305 {
 306         isl_dim *dim;
 307         struct isl_union_bound_data data = { type, 1, NULL };
 308
 309         if (!upwqp)
 310                 return NULL;
 311
 312         if (!tight)
 313                 data.tight = 0;
 314
 315         dim = isl_union_pw_qpolynomial_get_dim(upwqp);
 316         data.res = isl_union_pw_qpolynomial_fold_zero(dim, type);
 317         if (isl_union_pw_qpolynomial_foreach_pw_qpolynomial(upwqp,
 318                                                     &bound_pw, &data) < 0)
 319                 goto error;
 320
 321         isl_union_pw_qpolynomial_free(upwqp);
 322         if (tight)
 323                 *tight = data.tight;
 324
 325         return data.res;
 326 error:
 327         isl_union_pw_qpolynomial_free(upwqp);
 328         isl_union_pw_qpolynomial_fold_free(data.res);
 329         return NULL;
 330 }