Question

I can see from the GMP official documentation:

**void mpn_copyi (mp_limb_t rp, const mp_limb_t s1p, mp_size_t n)

Copy from {s1p, n} to {rp, n}, increasingly.

**void mpn_copyd (mp_limb_t rp, const mp_limb_t s1p, mp_size_t n)

Copy from {s1p, n} to {rp, n}, decreasingly.

However, I don’t understand what increasingly and decreasingly mean in this context. Does increasingly mean it will copy all the limbs from 0 to n?

Answer 1

Use the source, Teabee.

void
mpn_copyi (mp_ptr rp, mp_srcptr up, mp_size_t n)
{
  mp_size_t i;

  up += n;
  rp += n;
  for (i = -n; i != 0; i++)
    rp[i] = up[i];
}

And decrementing:

void
mpn_copyd (mp_ptr rp, mp_srcptr up, mp_size_t n)
{
  mp_size_t i;

  for (i = n - 1; i >= 0; i--)
    rp[i] = up[i];
}