isl_val_sioimath.c

   1 #include <isl_val_private.h>
   2
   3 /* Return a reference to an isl_val representing the unsigned
   4  * integer value stored in the "n" chunks of size "size" at "chunks".
   5  * The least significant chunk is assumed to be stored first.
   6  */
   7 __isl_give isl_val *isl_val_int_from_chunks(isl_ctx *ctx, size_t n,
   8         size_t size, const void *chunks)
   9 {
  10         isl_val *v;
  11
  12         v = isl_val_alloc(ctx);
  13         if (!v)
  14                 return NULL;
  15
  16         impz_import(isl_sioimath_reinit_big(&v->n), n, -1, size, 0, 0, chunks);
  17         isl_sioimath_try_demote(&v->n);
  18         isl_int_set_si(v->d, 1);
  19
  20         return v;
  21 }
  22
  23 /* Store a representation of the absolute value of the numerator of "v"
  24  * in terms of chunks of size "size" at "chunks".
  25  * The least significant chunk is stored first.
  26  * The number of chunks in the result can be obtained by calling
  27  * isl_val_n_abs_num_chunks.  The user is responsible for allocating
  28  * enough memory to store the results.
  29  *
  30  * In the special case of a zero value, isl_val_n_abs_num_chunks will
  31  * return one, while impz_export will not fill in any chunks.  We therefore
  32  * do it ourselves.
  33  */
  34 int isl_val_get_abs_num_chunks(__isl_keep isl_val *v, size_t size,
  35         void *chunks)
  36 {
  37         isl_sioimath_scratchspace_t scratch;
  38
  39         if (!v || !chunks)
  40                 return -1;
  41
  42         if (!isl_val_is_rat(v))
  43                 isl_die(isl_val_get_ctx(v), isl_error_invalid,
  44                         "expecting rational value", return -1);
  45
  46         impz_export(chunks, NULL, -1, size, 0, 0,
  47             isl_sioimath_bigarg_src(v->n, &scratch));
  48         if (isl_val_is_zero(v))
  49                 memset(chunks, 0, size);
  50
  51         return 0;
  52 }
  53
  54 /* Return the number of chunks of size "size" required to
  55  * store the absolute value of the numerator of "v".
  56  */
  57 size_t isl_val_n_abs_num_chunks(__isl_keep isl_val *v, size_t size)
  58 {
  59         if (!v)
  60                 return 0;
  61
  62         if (!isl_val_is_rat(v))
  63                 isl_die(isl_val_get_ctx(v), isl_error_invalid,
  64                         "expecting rational value", return 0);
  65
  66         size *= 8;
  67         return (isl_sioimath_sizeinbase(v->n, 2) + size - 1) / size;
  68 }