isl_val_imath.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(v->n, n, -1, size, 0, 0, chunks);
  17         isl_int_set_si(v->d, 1);
  18
  19         return v;
  20 }
  21
  22 /* Store a representation of the absolute value of the numerator of "v"
  23  * in terms of chunks of size "size" at "chunks".
  24  * The least significant chunk is stored first.
  25  * The number of chunks in the result can be obtained by calling
  26  * isl_val_n_abs_num_chunks.  The user is responsible for allocating
  27  * enough memory to store the results.
  28  *
  29  * In the special case of a zero value, isl_val_n_abs_num_chunks will
  30  * return one, while impz_export will not fill in any chunks.  We therefore
  31  * do it ourselves.
  32  */
  33 int isl_val_get_abs_num_chunks(__isl_keep isl_val *v, size_t size,
  34         void *chunks)
  35 {
  36         if (!v || !chunks)
  37                 return -1;
  38
  39         if (!isl_val_is_rat(v))
  40                 isl_die(isl_val_get_ctx(v), isl_error_invalid,
  41                         "expecting rational value", return -1);
  42
  43         impz_export(chunks, NULL, -1, size, 0, 0, v->n);
  44         if (isl_val_is_zero(v))
  45                 memset(chunks, 0, size);
  46
  47         return 0;
  48 }
  49
  50 /* Return the number of chunks of size "size" required to
  51  * store the absolute value of the numerator of "v".
  52  */
  53 size_t isl_val_n_abs_num_chunks(__isl_keep isl_val *v, size_t size)
  54 {
  55         if (!v)
  56                 return 0;
  57
  58         if (!isl_val_is_rat(v))
  59                 isl_die(isl_val_get_ctx(v), isl_error_invalid,
  60                         "expecting rational value", return 0);
  61
  62         size *= 8;
  63         return (impz_sizeinbase(v->n, 2) + size - 1) / size;
  64 }