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