New function mpz_init_setbit

[marco.bodrato at tutanota.com]

Ciao!

Do you mind if I add a new function?

Here is its implementation:

/* mpz_init_setbit(integer, val) -- Initialize and assign INTEGER with 2^VAL. */
void
mpz_init_setbit (mpz_ptr dest, mp_bitcnt_t bit_idx)
{
  mp_ptr dp;
  mp_size_t limb_idx = bit_idx / GMP_NUMB_BITS;
  mp_limb_t mask = CNST_LIMB(1) << (bit_idx % GMP_NUMB_BITS);

  ALLOC (dest) = SIZ (dest) = limb_idx + 1;
  PTR (dest) = dp = __GMP_ALLOCATE_FUNC_LIMBS (limb_idx + 1);
  MPN_ZERO (dp, limb_idx);
  dp[limb_idx] = mask;
}

And in mini-gmp:
void
mpz_init_setbit (mpz_t r, mp_bitcnt_t b)
{
  mpz_init (r);
  /* mpz_setbit (r, b); */
  mpz_abs_add_bit (r, b);
}

Ĝis,
m-- 
DC: https://vado.li/dc-bodrato