New function mpz_init_setbit

[Torbjörn Granlund]

marco.bodrato at tutanota.com writes:

  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;
  }

I suppose that the name should be mpz_set_2exp, for consistency?

-- 
Torbjörn
Please encrypt, key id 0xC8601622