isl_local.c

   1 /*
   2  * Copyright 2011      INRIA Saclay
   3  * Copyright 2014      Ecole Normale Superieure
   4  *
   5  * Use of this software is governed by the MIT license
   6  *
   7  * Written by Sven Verdoolaege, INRIA Saclay - Ile-de-France,
   8  * Parc Club Orsay Universite, ZAC des vignes, 4 rue Jacques Monod,
   9  * 91893 Orsay, France
  10  * and Ecole Normale Superieure, 45 rue d'Ulm, 75230 Paris, France
  11  */
  12
  13 #include <isl/space.h>
  14 #include <isl_vec_private.h>
  15 #include <isl_mat_private.h>
  16 #include <isl_reordering.h>
  17 #include <isl_seq.h>
  18 #include <isl_local.h>
  19
  20 /* Return the isl_ctx to which "local" belongs.
  21  */
  22 isl_ctx *isl_local_get_ctx(__isl_keep isl_local *local)
  23 {
  24         if (!local)
  25                 return NULL;
  26
  27         return isl_mat_get_ctx(local);
  28 }
  29
  30 /* Create an isl_local object from a matrix describing
  31  * integer divisions.
  32  *
  33  * An isl_local object is current defined as exactly such a matrix,
  34  * so simply return the input.
  35  */
  36 __isl_give isl_local *isl_local_alloc_from_mat(__isl_take isl_mat *mat)
  37 {
  38         return mat;
  39 }
  40
  41 /* Free "local" and return NULL.
  42  */
  43 __isl_null isl_local *isl_local_free(__isl_take isl_local *local)
  44 {
  45         isl_mat_free(local);
  46         return NULL;
  47 }
  48
  49 /* Return the number of local variables (isl_dim_div),
  50  * the number of other variables (isl_dim_set) or
  51  * the total number of variables (isl_dim_all) in "local".
  52  *
  53  * Other types do not have any meaning for an isl_local object.
  54  */
  55 int isl_local_dim(__isl_keep isl_local *local, enum isl_dim_type type)
  56 {
  57         isl_mat *mat = local;
  58
  59         if (!local)
  60                 return 0;
  61         if (type == isl_dim_div)
  62                 return isl_mat_rows(mat);
  63         if (type == isl_dim_all)
  64                 return isl_mat_cols(mat) - 2;
  65         if (type == isl_dim_set)
  66                 return isl_local_dim(local, isl_dim_all) -
  67                         isl_local_dim(local, isl_dim_div);
  68         isl_die(isl_local_get_ctx(local), isl_error_unsupported,
  69                 "unsupported dimension type", return 0);
  70 }
  71
  72 /* Check that "pos" is a valid position for a variable in "local".
  73  */
  74 static isl_stat isl_local_check_pos(__isl_keep isl_local *local, int pos)
  75 {
  76         if (!local)
  77                 return isl_stat_error;
  78         if (pos < 0 || pos >= isl_local_dim(local, isl_dim_div))
  79                 isl_die(isl_local_get_ctx(local), isl_error_invalid,
  80                         "position out of bounds", return isl_stat_error);
  81         return isl_stat_ok;
  82 }
  83
  84 /* Given local variables "local",
  85  * is the variable at position "pos" marked as not having
  86  * an explicit representation?
  87  * Note that even if this variable is not marked in this way and therefore
  88  * does have an explicit representation, this representation may still
  89  * depend (indirectly) on other local variables that do not
  90  * have an explicit representation.
  91  */
  92 isl_bool isl_local_div_is_marked_unknown(__isl_keep isl_local *local, int pos)
  93 {
  94         isl_mat *mat = local;
  95
  96         if (isl_local_check_pos(local, pos) < 0)
  97                 return isl_bool_error;
  98         return isl_int_is_zero(mat->row[pos][0]);
  99 }
 100
 101 /* Given local variables "local",
 102  * does the variable at position "pos" have a complete explicit representation?
 103  * Having a complete explicit representation requires not only
 104  * an explicit representation, but also that all local variables
 105  * that appear in this explicit representation in turn have
 106  * a complete explicit representation.
 107  */
 108 isl_bool isl_local_div_is_known(__isl_keep isl_local *local, int pos)
 109 {
 110         isl_bool marked;
 111         int i, n, off;
 112         isl_mat *mat = local;
 113
 114         if (isl_local_check_pos(local, pos) < 0)
 115                 return isl_bool_error;
 116
 117         marked = isl_local_div_is_marked_unknown(local, pos);
 118         if (marked < 0 || marked)
 119                 return isl_bool_not(marked);
 120
 121         n = isl_local_dim(local, isl_dim_div);
 122         off = isl_mat_cols(mat) - n;
 123
 124         for (i = n - 1; i >= 0; --i) {
 125                 isl_bool known;
 126
 127                 if (isl_int_is_zero(mat->row[pos][off + i]))
 128                         continue;
 129                 known = isl_local_div_is_known(local, i);
 130                 if (known < 0 || !known)
 131                         return known;
 132         }
 133
 134         return isl_bool_true;
 135 }
 136
 137 /* Does "local" have an explicit representation for all local variables?
 138  */
 139 isl_bool isl_local_divs_known(__isl_keep isl_local *local)
 140 {
 141         int i, n;
 142
 143         if (!local)
 144                 return isl_bool_error;
 145
 146         n = isl_local_dim(local, isl_dim_div);
 147         for (i = 0; i < n; ++i) {
 148                 isl_bool unknown = isl_local_div_is_marked_unknown(local, i);
 149                 if (unknown < 0 || unknown)
 150                         return isl_bool_not(unknown);
 151         }
 152
 153         return isl_bool_true;
 154 }
 155
 156 /* Compare two sets of local variables, defined over
 157  * the same space.
 158  *
 159  * Return -1 if "local1" is "smaller" than "local2", 1 if "local1" is "greater"
 160  * than "local2" and 0 if they are equal.
 161  *
 162  * The order is fairly arbitrary.  We do "prefer" divs that only involve
 163  * earlier dimensions in the sense that we consider matrices where
 164  * the first differing div involves earlier dimensions to be smaller.
 165  */
 166 int isl_local_cmp(__isl_keep isl_local *local1, __isl_keep isl_local *local2)
 167 {
 168         int i;
 169         int cmp;
 170         isl_bool unknown1, unknown2;
 171         int last1, last2;
 172         int n_col;
 173         isl_mat *mat1 = local1;
 174         isl_mat *mat2 = local2;
 175
 176         if (local1 == local2)
 177                 return 0;
 178         if (!local1)
 179                 return -1;
 180         if (!local2)
 181                 return 1;
 182
 183         if (mat1->n_row != mat2->n_row)
 184                 return mat1->n_row - mat2->n_row;
 185
 186         n_col = isl_mat_cols(mat1);
 187         for (i = 0; i < mat1->n_row; ++i) {
 188                 unknown1 = isl_local_div_is_marked_unknown(local1, i);
 189                 unknown2 = isl_local_div_is_marked_unknown(local2, i);
 190                 if (unknown1 && unknown2)
 191                         continue;
 192                 if (unknown1)
 193                         return 1;
 194                 if (unknown2)
 195                         return -1;
 196                 last1 = isl_seq_last_non_zero(mat1->row[i] + 1, n_col - 1);
 197                 last2 = isl_seq_last_non_zero(mat2->row[i] + 1, n_col - 1);
 198                 if (last1 != last2)
 199                         return last1 - last2;
 200                 cmp = isl_seq_cmp(mat1->row[i], mat2->row[i], n_col);
 201                 if (cmp != 0)
 202                         return cmp;
 203         }
 204
 205         return 0;
 206 }
 207
 208 /* Reorder the columns of the given local variables according to the
 209  * given reordering.
 210  * The order of the local variables themselves is assumed not to change.
 211  */
 212 __isl_give isl_local *isl_local_reorder(__isl_take isl_local *local,
 213         __isl_take isl_reordering *r)
 214 {
 215         isl_mat *div = local;
 216         int i, j;
 217         isl_space *space;
 218         isl_mat *mat;
 219         int extra;
 220
 221         if (!local || !r)
 222                 goto error;
 223
 224         space = isl_reordering_peek_space(r);
 225         extra = isl_space_dim(space, isl_dim_all) + div->n_row - r->len;
 226         mat = isl_mat_alloc(div->ctx, div->n_row, div->n_col + extra);
 227         if (!mat)
 228                 goto error;
 229
 230         for (i = 0; i < div->n_row; ++i) {
 231                 isl_seq_cpy(mat->row[i], div->row[i], 2);
 232                 isl_seq_clr(mat->row[i] + 2, mat->n_col - 2);
 233                 for (j = 0; j < r->len; ++j)
 234                         isl_int_set(mat->row[i][2 + r->pos[j]],
 235                                     div->row[i][2 + j]);
 236         }
 237
 238         isl_reordering_free(r);
 239         isl_local_free(local);
 240         return isl_local_alloc_from_mat(mat);
 241 error:
 242         isl_reordering_free(r);
 243         isl_local_free(local);
 244         return NULL;
 245 }
 246
 247 /* Extend a vector "v" representing an integer point
 248  * in the domain space of "local"
 249  * to one that also includes values for the local variables.
 250  * All local variables are required to have an explicit representation.
 251  */
 252 __isl_give isl_vec *isl_local_extend_point_vec(__isl_keep isl_local *local,
 253         __isl_take isl_vec *v)
 254 {
 255         unsigned n_div;
 256         isl_bool known;
 257         isl_mat *mat = local;
 258
 259         if (!local || !v)
 260                 return isl_vec_free(v);
 261         known = isl_local_divs_known(local);
 262         if (known < 0)
 263                 return isl_vec_free(v);
 264         if (!known)
 265                 isl_die(isl_local_get_ctx(local), isl_error_invalid,
 266                         "unknown local variables", return isl_vec_free(v));
 267         if (isl_vec_size(v) != 1 + isl_local_dim(local, isl_dim_set))
 268                 isl_die(isl_local_get_ctx(local), isl_error_invalid,
 269                         "incorrect size", return isl_vec_free(v));
 270         if (!isl_int_is_one(v->el[0]))
 271                 isl_die(isl_local_get_ctx(local), isl_error_invalid,
 272                         "expecting integer point", return isl_vec_free(v));
 273         n_div = isl_local_dim(local, isl_dim_div);
 274         if (n_div != 0) {
 275                 int i;
 276                 unsigned dim = isl_local_dim(local, isl_dim_set);
 277                 v = isl_vec_add_els(v, n_div);
 278                 if (!v)
 279                         return NULL;
 280
 281                 for (i = 0; i < n_div; ++i) {
 282                         isl_seq_inner_product(mat->row[i] + 1, v->el,
 283                                                 1 + dim + i, &v->el[1+dim+i]);
 284                         isl_int_fdiv_q(v->el[1+dim+i], v->el[1+dim+i],
 285                                         mat->row[i][0]);
 286                 }
 287         }
 288
 289         return v;
 290 }