Example #1
0
static void BM_count_leading_zeros_noasm(benchmark::State& state) {
	UINT32 cnt = 0x332533;
	while (state.KeepRunning()) {
		(void)count_leading_zeros(cnt);
		cnt++;
	}
}
Example #2
0
static inline std::size_t countleadbits(std::size_t x)
{
#ifndef count_leading_zeros
	std::size_t msk;
	std::size_t ret;
	if (x < 0x100)
	{
		msk = 0x80;
		ret = 24;
	}
	else if (x < 0x10000)
	{
		msk = 0x8000;
		ret = 16;
	}
	else if (x < 0x1000000)
	{
		msk = 0x800000;
		ret = 8;
	}
	else
	{
		msk = 0x80000000;
		ret = 0;
	}
	while ((msk & x) == 0 && ret < 31)
	{
		msk = msk >> 1;
		ret++;
	}
	return ret;
#else
	return count_leading_zeros(x);
#endif
}
Example #3
0
int
mpfr_ui_div (mpfr_ptr y, unsigned long int u, mpfr_srcptr x, mpfr_rnd_t rnd_mode)
{
  mpfr_t uu;
  mp_limb_t up[1];
  unsigned long cnt;

  MPFR_LOG_FUNC
    (("u=%lu x[%Pu]=%.*Rg rnd=%d",
      u, mpfr_get_prec(x), mpfr_log_prec, x, rnd_mode),
     ("y[%Pu]=%.*Rg", mpfr_get_prec(y), mpfr_log_prec, y));

  if (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x)))
    {
      if (MPFR_IS_NAN(x))
        {
          MPFR_SET_NAN(y);
          MPFR_RET_NAN;
        }
      else if (MPFR_IS_INF(x)) /* u/Inf = 0 */
        {
          MPFR_SET_ZERO(y);
          MPFR_SET_SAME_SIGN(y,x);
          MPFR_RET(0);
        }
      else /* u / 0 */
        {
          MPFR_ASSERTD(MPFR_IS_ZERO(x));
          if (u)
            {
              /* u > 0, so y = sign(x) * Inf */
              MPFR_SET_SAME_SIGN(y, x);
              MPFR_SET_INF(y);
              mpfr_set_divby0 ();
              MPFR_RET(0);
            }
          else
            {
              /* 0 / 0 */
              MPFR_SET_NAN(y);
              MPFR_RET_NAN;
            }
        }
    }
  else if (MPFR_LIKELY(u != 0))
    {
      MPFR_TMP_INIT1(up, uu, GMP_NUMB_BITS);
      MPFR_ASSERTN(u == (mp_limb_t) u);
      count_leading_zeros(cnt, (mp_limb_t) u);
      up[0] = (mp_limb_t) u << cnt;
      MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt);
      return mpfr_div (y, uu, x, rnd_mode);
    }
  else /* u = 0, and x != 0 */
    {
      MPFR_SET_ZERO(y);         /* if u=0, then set y to 0 */
      MPFR_SET_SAME_SIGN(y, x); /* u considered as +0: sign(+0/x) = sign(x) */
      MPFR_RET(0);
    }
}
Example #4
0
int
mpfr_urandomb (mpfr_ptr rop, gmp_randstate_t rstate)
{
  mp_ptr rp;
  mp_prec_t nbits;
  mp_size_t nlimbs;
  mp_size_t k; /* number of high zero limbs */
  mp_exp_t exp;
  int cnt;

  MPFR_CLEAR_FLAGS (rop);

  rp = MPFR_MANT (rop);
  nbits = MPFR_PREC (rop);
  nlimbs = MPFR_LIMB_SIZE (rop);
  MPFR_SET_POS (rop);

  /* Uniform non-normalized significand */
  _gmp_rand (rp, rstate, nlimbs * BITS_PER_MP_LIMB);

  /* If nbits isn't a multiple of BITS_PER_MP_LIMB, mask the low bits */
  cnt = nlimbs * BITS_PER_MP_LIMB - nbits;
  if (MPFR_LIKELY (cnt != 0))
    rp[0] &= ~MPFR_LIMB_MASK (cnt);

  /* Count the null significant limbs and remaining limbs */
  exp = 0;
  k = 0;
  while (nlimbs != 0 && rp[nlimbs - 1] == 0)
    {
      k ++;
      nlimbs --;
      exp -= BITS_PER_MP_LIMB;
    }

  if (MPFR_LIKELY (nlimbs != 0)) /* otherwise value is zero */
    {
      count_leading_zeros (cnt, rp[nlimbs - 1]);
      /* Normalization */
      if (mpfr_set_exp (rop, exp - cnt))
        {
          /* If the exponent is not in the current exponent range, we
             choose to return a NaN as this is probably a user error.
             Indeed this can happen only if the exponent range has been
             reduced to a very small interval and/or the precision is
             huge (very unlikely). */
          MPFR_SET_NAN (rop);
          __gmpfr_flags |= MPFR_FLAGS_NAN; /* Can't use MPFR_RET_NAN */
          return 1;
        }
      if (cnt != 0)
        mpn_lshift (rp + k, rp, nlimbs, cnt);
      if (k != 0)
        MPN_ZERO (rp, k);
    }
  else
    MPFR_SET_ZERO (rop);

  return 0;
}
		data_chunk decode_base58(std::string encoded)
		{
			// Trim spaces and newlines around the string.
			boost::algorithm::trim(encoded);
			size_t leading_zeros = count_leading_zeros(encoded);

			// log(58) / log(256), rounded up.
			const size_t data_size = encoded.size() * 733 / 1000 + 1;
			// Allocate enough space in big-endian base256 representation.
			data_chunk data(data_size);

			// Process the characters.
			for (auto it = encoded.begin() + leading_zeros; it != encoded.end(); ++it)
			{
				size_t carry = base58_chars.find(*it);
				if (carry == std::string::npos)
					return data_chunk();
				unpack_char(data, carry);
			}

			// Skip leading zeroes in data.
			auto first_nonzero = search_first_nonzero(data);

			// Copy result into output vector.
			data_chunk decoded;
			const size_t estimated_size =
				leading_zeros + (data.end() - first_nonzero);
			decoded.reserve(estimated_size);
			decoded.assign(leading_zeros, 0x00);
			decoded.insert(decoded.end(), first_nonzero, data.cend());
			return decoded;
		}
Example #6
0
void
mpfr_random2 (mpfr_ptr x, mp_size_t size, mp_exp_t exp)
{
  mp_size_t xn;
  unsigned long cnt;
  mp_ptr xp = MPFR_MANT(x), yp[1];
  mp_size_t prec = (MPFR_PREC(x) - 1)/BITS_PER_MP_LIMB; 

  MPFR_CLEAR_FLAGS(x);
  xn = ABS (size);
  if (xn != 0)
    {
      if (xn > prec + 1)
	xn = prec + 1;

      mpn_random2 (xp, xn);
    }

  if (exp != 0) {
    /* use mpn_random instead of random since that function is not
       available on all platforms (for example HPUX, DEC OSF, ...) */
    mpn_random ((mp_limb_t*) yp, 1);
    exp = (mp_exp_t) yp[0] % (2 * exp) - exp;
  }

  count_leading_zeros(cnt, xp[xn - 1]); 
  if (cnt) mpn_lshift(xp, xp, xn, cnt); 
  MPFR_EXP(x) = exp-cnt; 
  cnt = xn*BITS_PER_MP_LIMB - prec; 
  /* cnt is the number of non significant bits in the low limb */
  xp[0] &= ~((MP_LIMB_T_ONE << cnt) - MP_LIMB_T_ONE);
}
Example #7
0
static inline unsigned countleadbits(unsigned x)
{
#ifndef count_leading_zeros
	unsigned msk;
	unsigned ret;
	if (x < 0x100)
	{
		msk = 0x80;
		ret = 24;
	}
	else if (x < 0x10000)
	{
		msk = 0x8000;
		ret = 16;
	}
	else if (x < 0x1000000)
	{
		msk = 0x800000;
		ret = 8;
	}
	else
	{
		msk = 0x80000000;
		ret = 0;
	}
	while ((msk & x) == 0 && ret < 31)
	{
		msk = msk >> 1;
		ret++;
	}
	return ret;
#else
	return count_leading_zeros(x);
#endif
}
		std::string encode_base58(const data_chunk& unencoded)
		{
			size_t leading_zeros = count_leading_zeros(unencoded);

			// size = log(256) / log(58), rounded up.
			const size_t number_nonzero = unencoded.size() - leading_zeros;
			const size_t indexes_size = number_nonzero * 138 / 100 + 1;
			// Allocate enough space in big-endian base58 representation.
			data_chunk indexes(indexes_size);

			// Process the bytes.
			for (auto it = unencoded.begin() + leading_zeros;
				it != unencoded.end(); ++it)
			{
				pack_value(indexes, *it);
			}

			// Skip leading zeroes in base58 result.
			auto first_nonzero = search_first_nonzero(indexes);

			// Translate the result into a string.
			std::string encoded;
			const size_t estimated_size =
				leading_zeros + (indexes.end() - first_nonzero);
			encoded.reserve(estimated_size);
			encoded.assign(leading_zeros, '1');
			// Set actual main bytes.
			for (auto it = first_nonzero; it != indexes.end(); ++it)
			{
				const size_t index = *it;
				encoded += base58_chars[index];
			}
			return encoded;
		}
Example #9
0
double
mpz_get_d_2exp (signed long int *exp2, mpz_srcptr src)
{
  double res;
  mp_size_t size, i, n_limbs_to_use;
  int negative;
  mp_ptr qp;
  int cnt;

  size = SIZ(src);
  if (size == 0)
    {
      *exp2 = 0;
      return 0.0;
    }

  negative = size < 0;
  size = ABS (size);
  qp = PTR(src);

  n_limbs_to_use = MIN (LIMBS_PER_DOUBLE, size);
  qp += size - n_limbs_to_use;
  res = qp[0] / MP_BASE_AS_DOUBLE;
  for (i = 1; i < n_limbs_to_use; i++)
    res = (res + qp[i]) / MP_BASE_AS_DOUBLE;
  count_leading_zeros (cnt, qp[n_limbs_to_use - 1]);
  *exp2 = size * BITS_PER_MP_LIMB - cnt;
  res = res * ((mp_limb_t) 1 << cnt);

  return negative ? -res : res;
}
Example #10
0
double
mpf_get_d_2exp (signed long *exp2, mpf_srcptr src)
{
  mp_size_t size, abs_size;
  mp_srcptr ptr;
  int cnt;
  signed long exp;

  size = SIZ(src);
  if (UNLIKELY (size == 0))
    {
      *exp2 = 0;
      return 0.0;
    }

  ptr = PTR(src);
  abs_size = ABS (size);
  count_leading_zeros (cnt, ptr[abs_size - 1]);
  cnt -= GMP_NAIL_BITS;

  exp = EXP(src) * GMP_NUMB_BITS - cnt;
  *exp2 = exp;

  return mpn_get_d (ptr, abs_size, size,
                    (long) - (abs_size * GMP_NUMB_BITS - cnt));
}
Example #11
0
int
mpfr_sub_ui (mpfr_ptr y, mpfr_srcptr x, unsigned long int u, mp_rnd_t rnd_mode)
{
  if (MPFR_LIKELY (u != 0))  /* if u=0, do nothing */
    {
      mpfr_t uu;
      mp_limb_t up[1];
      unsigned long cnt;
      int inex;

      MPFR_SAVE_EXPO_DECL (expo);

      MPFR_TMP_INIT1 (up, uu, BITS_PER_MP_LIMB);
      MPFR_ASSERTN (u == (mp_limb_t) u);
      count_leading_zeros (cnt, (mp_limb_t) u);
      *up = (mp_limb_t) u << cnt;

      /* Optimization note: Exponent save/restore operations may be
         removed if mpfr_sub works even when uu is out-of-range. */
      MPFR_SAVE_EXPO_MARK (expo);
      MPFR_SET_EXP (uu, BITS_PER_MP_LIMB - cnt);
      inex = mpfr_sub (y, x, uu, rnd_mode);
      MPFR_SAVE_EXPO_FREE (expo);
      return mpfr_check_range (y, inex, rnd_mode);
    }
  else
    return mpfr_set (y, x, rnd_mode);
}
Example #12
0
size_t
mpn_sizeinbase (mp_srcptr xp, mp_size_t xsize, int base)
{
  int lb_base, cnt;
  mp_size_t totbits;

  ASSERT (xsize >= 0);
  ASSERT (base >= 2);
  ASSERT (base < numberof (__mp_bases));

  /* Special case for X == 0.  */
  if (xsize == 0)
    return 1;

  /* Calculate the total number of significant bits of X.  */
  count_leading_zeros (cnt, xp[xsize-1]);
  totbits = xsize * BITS_PER_MP_LIMB - cnt;

  if (POW2_P (base))
    {
      /* Special case for powers of 2, giving exact result.  */
      lb_base = __mp_bases[base].big_base;
      return (totbits + lb_base - 1) / lb_base;
    }
  else
    return (size_t) (totbits * __mp_bases[base].chars_per_bit_exactly) + 1;
}
Example #13
0
int
mpfr_add_ui (mpfr_ptr y, mpfr_srcptr x, unsigned long int u, mp_rnd_t rnd_mode)
{

  if (u)  /* if u=0, do nothing */
    {
      mpfr_t uu;
      mp_limb_t up[1];
      unsigned long cnt;
      int inex;

      MPFR_INIT1(up, uu, BITS_PER_MP_LIMB, 1);
      count_leading_zeros(cnt, (mp_limb_t) u);
      *up = (mp_limb_t) u << cnt;
      MPFR_EXP(uu) = BITS_PER_MP_LIMB - cnt;

      /* Optimization note: Exponent operations may be removed
	 if mpfr_add works even when uu is out-of-range. */
      mpfr_save_emin_emax();
      inex = mpfr_add(y, x, uu, rnd_mode);
      MPFR_RESTORE_RET(inex, y, rnd_mode);
    }
  else
    return mpfr_set (y, x, rnd_mode);
}
Example #14
0
/*
 * Set f to z, choosing the smallest precision for f
 * so that z = f*(2^BPML)*zs*2^(RetVal)
 */
static int
set_z (mpfr_ptr f, mpz_srcptr z, mp_size_t *zs)
{
  mp_limb_t *p;
  mp_size_t s;
  int c;
  mp_prec_t pf;

  MPFR_ASSERTD (mpz_sgn (z) != 0);

  /* Remove useless ending 0 */
  for (p = PTR (z), s = *zs = ABS (SIZ (z)) ; *p == 0; p++, s--)
    MPFR_ASSERTD (s >= 0);

  /* Get working precision */
  count_leading_zeros (c, p[s-1]);
  pf = s * BITS_PER_MP_LIMB - c;
  if (pf < MPFR_PREC_MIN)
    pf = MPFR_PREC_MIN;
  mpfr_init2 (f, pf);

  /* Copy Mantissa */
  if (MPFR_LIKELY (c))
    mpn_lshift (MPFR_MANT (f), p, s, c);
  else
    MPN_COPY (MPFR_MANT (f), p, s);

  MPFR_SET_SIGN (f, mpz_sgn (z));
  MPFR_SET_EXP (f, 0);

  return -c;
}
Example #15
0
int
mpfr_add_ui (mpfr_ptr y, mpfr_srcptr x, unsigned long int u, mpfr_rnd_t rnd_mode)
{
  MPFR_LOG_FUNC
    (("x[%Pu]=%.*Rg u=%lu rnd=%d",
      mpfr_get_prec(x), mpfr_log_prec, x, u, rnd_mode),
     ("y[%Pu]=%.*Rg", mpfr_get_prec (y), mpfr_log_prec, y));

  if (MPFR_LIKELY(u != 0) )  /* if u=0, do nothing */
    {
      mpfr_t uu;
      mp_limb_t up[1];
      unsigned long cnt;
      int inex;
      MPFR_SAVE_EXPO_DECL (expo);

      MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS);
      MPFR_ASSERTD (u == (mp_limb_t) u);
      count_leading_zeros(cnt, (mp_limb_t) u);
      up[0] = (mp_limb_t) u << cnt;

      /* Optimization note: Exponent save/restore operations may be
         removed if mpfr_add works even when uu is out-of-range. */
      MPFR_SAVE_EXPO_MARK (expo);
      MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt);
      inex = mpfr_add(y, x, uu, rnd_mode);
      MPFR_SAVE_EXPO_FREE (expo);
      return mpfr_check_range(y, inex, rnd_mode);
    }
  else
    /* (unsigned long) 0 is assumed to be a real 0 (unsigned) */
    return mpfr_set (y, x, rnd_mode);
}
Example #16
0
int
mpfr_sqrt_ui (mpfr_ptr r, unsigned long u, mpfr_rnd_t rnd_mode)
{
  if (u)
    {
      mpfr_t uu;
      mp_limb_t up[1];
      unsigned long cnt;
      int inex;
      MPFR_SAVE_EXPO_DECL (expo);

      MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS);
      MPFR_ASSERTN (u == (mp_limb_t) u);
      count_leading_zeros (cnt, (mp_limb_t) u);
      *up = (mp_limb_t) u << cnt;

      MPFR_SAVE_EXPO_MARK (expo);
      MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt);
      inex = mpfr_sqrt(r, uu, rnd_mode);
      MPFR_SAVE_EXPO_FREE (expo);
      return mpfr_check_range(r, inex, rnd_mode);
    }
  else /* sqrt(0) = 0 */
    {
      MPFR_SET_ZERO(r);
      MPFR_SET_POS(r);
      MPFR_RET(0);
    }
}
Example #17
0
/* set f to the integer z multiplied by 2^e */
int
mpfr_set_z_2exp (mpfr_ptr f, mpz_srcptr z, mpfr_exp_t e, mpfr_rnd_t rnd_mode)
{
    mp_size_t fn, zn, dif, en;
    int k, sign_z, inex;
    mp_limb_t *fp, *zp;
    mpfr_exp_t exp;

    sign_z = mpz_sgn (z);
    if (MPFR_UNLIKELY (sign_z == 0)) /* ignore the exponent for 0 */
    {
        MPFR_SET_ZERO(f);
        MPFR_SET_POS(f);
        MPFR_RET(0);
    }
    MPFR_ASSERTD (sign_z == MPFR_SIGN_POS || sign_z == MPFR_SIGN_NEG);

    zn = ABS(SIZ(z)); /* limb size of z */
    /* compute en = floor(e/GMP_NUMB_BITS) */
    en = (e >= 0) ? e / GMP_NUMB_BITS : (e + 1) / GMP_NUMB_BITS - 1;
    MPFR_ASSERTD (zn >= 1);
    if (MPFR_UNLIKELY (zn + en > MPFR_EMAX_MAX / GMP_NUMB_BITS + 1))
        return mpfr_overflow (f, rnd_mode, sign_z);
    /* because zn + en >= MPFR_EMAX_MAX / GMP_NUMB_BITS + 2
       implies (zn + en) * GMP_NUMB_BITS >= MPFR_EMAX_MAX + GMP_NUMB_BITS + 1
       and exp = zn * GMP_NUMB_BITS + e - k
               >= (zn + en) * GMP_NUMB_BITS - k > MPFR_EMAX_MAX */

    fp = MPFR_MANT (f);
    fn = MPFR_LIMB_SIZE (f);
    dif = zn - fn;
    zp = PTR(z);
    count_leading_zeros (k, zp[zn-1]);

    /* now zn + en <= MPFR_EMAX_MAX / GMP_NUMB_BITS + 1
       thus (zn + en) * GMP_NUMB_BITS <= MPFR_EMAX_MAX + GMP_NUMB_BITS
       and exp = zn * GMP_NUMB_BITS + e - k
               <= (zn + en) * GMP_NUMB_BITS - k + GMP_NUMB_BITS - 1
               <= MPFR_EMAX_MAX + 2 * GMP_NUMB_BITS - 1 */
    exp = (mpfr_prec_t) zn * GMP_NUMB_BITS + e - k;
    /* The exponent will be exp or exp + 1 (due to rounding) */
    if (MPFR_UNLIKELY (exp > __gmpfr_emax))
        return mpfr_overflow (f, rnd_mode, sign_z);
    if (MPFR_UNLIKELY (exp + 1 < __gmpfr_emin))
        return mpfr_underflow (f, rnd_mode == MPFR_RNDN ? MPFR_RNDZ : rnd_mode,
                               sign_z);

    if (MPFR_LIKELY (dif >= 0))
    {
        mp_limb_t rb, sb, ulp;
        int sh;

        /* number has to be truncated */
        if (MPFR_LIKELY (k != 0))
        {
            mpn_lshift (fp, &zp[dif], fn, k);
            if (MPFR_LIKELY (dif > 0))
                fp[0] |= zp[dif - 1] >> (GMP_NUMB_BITS - k);
        }
void
my__gmpn_tdiv_qr (mp_ptr qp, mp_ptr rp, mp_size_t qxn,
mp_srcptr np, mp_size_t nn, mp_srcptr dp, mp_size_t dn)
{
	ASSERT_ALWAYS (qxn == 0);

	ASSERT (nn >= 0);
	ASSERT (dn >= 0);
	ASSERT (dn == 0 || dp[dn - 1] != 0);
	ASSERT (! MPN_OVERLAP_P (qp, nn - dn + 1 + qxn, np, nn));
	ASSERT (! MPN_OVERLAP_P (qp, nn - dn + 1 + qxn, dp, dn));

	int adjust;
	gmp_pi1_t dinv;
	TMP_DECL;
	TMP_MARK;
								 /* conservative tests for quotient size */
	adjust = np[nn - 1] >= dp[dn - 1];
	mp_ptr n2p, d2p;
	mp_limb_t cy;
	int cnt;

	qp[nn - dn] = 0;			 /* zero high quotient limb */
	count_leading_zeros (cnt, dp[dn - 1]);
	cnt -= GMP_NAIL_BITS;
	d2p = TMP_ALLOC_LIMBS (dn);
	mpn_lshift (d2p, dp, dn, cnt);

	for (int i=0; i<dn; i+=1)
	{
		printf("d2p %08x\n", *( (int*) (((void*)(d2p))+(i*4))));
	}


	n2p = TMP_ALLOC_LIMBS (nn + 1);
	cy = mpn_lshift (n2p, np, nn, cnt);
	for (int i=0; i<nn; i+=1)
	{
		printf("n2p %08x\n", *( (int*) (((void*)(n2p))+(i*4))));
	}
	n2p[nn] = cy;
	nn += adjust;

        printf("d2p[dn-1] = %08lx\nd2p[dn-2] = %08lx\n", d2p[dn-1], d2p[dn-2]);
	invert_pi1 (dinv, d2p[dn - 1], d2p[dn - 2]);
        printf("dinv %08lx\n", dinv.inv32);
	my_mpn_sbpi1_div_qr (qp, n2p, nn, d2p, dn, dinv.inv32);
	for (int i=0; i<nn; i+=1)
	{
		printf("inside qp %08x\n", *( (int*) (((void*)(qp))+(i*4))));
	}
	n2p[nn] = cy;

	mpn_rshift (rp, n2p, dn, cnt);
	TMP_FREE;
	return;

}
Example #19
0
int
mpfr_urandomb (mpfr_ptr rop, gmp_randstate_t rstate)
{
    mpfr_limb_ptr rp;
    mpfr_prec_t nbits;
    mp_size_t nlimbs;
    mp_size_t k; /* number of high zero limbs */
    mpfr_exp_t exp;
    int cnt;

    rp = MPFR_MANT (rop);
    nbits = MPFR_PREC (rop);
    nlimbs = MPFR_LIMB_SIZE (rop);
    MPFR_SET_POS (rop);
    cnt = nlimbs * GMP_NUMB_BITS - nbits;

    /* Uniform non-normalized significand */
    /* generate exactly nbits so that the random generator stays in the same
       state, independent of the machine word size GMP_NUMB_BITS */
    mpfr_rand_raw (rp, rstate, nbits);
    if (MPFR_LIKELY (cnt != 0)) /* this will put the low bits to zero */
        mpn_lshift (rp, rp, nlimbs, cnt);

    /* Count the null significant limbs and remaining limbs */
    exp = 0;
    k = 0;
    while (nlimbs != 0 && rp[nlimbs - 1] == 0)
    {
        k ++;
        nlimbs --;
        exp -= GMP_NUMB_BITS;
    }

    if (MPFR_LIKELY (nlimbs != 0)) /* otherwise value is zero */
    {
        count_leading_zeros (cnt, rp[nlimbs - 1]);
        /* Normalization */
        if (mpfr_set_exp (rop, exp - cnt))
        {
            /* If the exponent is not in the current exponent range, we
               choose to return a NaN as this is probably a user error.
               Indeed this can happen only if the exponent range has been
               reduced to a very small interval and/or the precision is
               huge (very unlikely). */
            MPFR_SET_NAN (rop);
            __gmpfr_flags |= MPFR_FLAGS_NAN; /* Can't use MPFR_RET_NAN */
            return 1;
        }
        if (cnt != 0)
            mpn_lshift (rp + k, rp, nlimbs, cnt);
        if (k != 0)
            MPN_ZERO (rp, k);
    }
    else
        MPFR_SET_ZERO (rop);

    return 0;
}
Example #20
0
UTItype
__udivmodti4 (UTItype num, UTItype den, UTItype * rp)
{
  qword shift =
    si_from_uint (count_leading_zeros (den) - count_leading_zeros (num));
  qword n0 = si_from_UTItype (num);
  qword d0 = si_from_UTItype (den);
  qword bit = si_andi (si_fsmbi (1), 1);
  qword r0 = si_il (0);
  qword m1 = si_fsmbi (0x000f);
  qword mask, r1, n1;

  d0 = si_shlqbybi (si_shlqbi (d0, shift), shift);
  bit = si_shlqbybi (si_shlqbi (bit, shift), shift);

  do
    {
      r1 = si_or (r0, bit);

      // n1 = n0 - d0 in TImode
      n1 = si_bg (d0, n0);
      n1 = si_shlqbyi (n1, 4);
      n1 = si_sf (m1, n1);
      n1 = si_bgx (d0, n0, n1);
      n1 = si_shlqbyi (n1, 4);
      n1 = si_sf (m1, n1);
      n1 = si_bgx (d0, n0, n1);
      n1 = si_shlqbyi (n1, 4);
      n1 = si_sf (m1, n1);
      n1 = si_sfx (d0, n0, n1);

      mask = si_fsm (si_cgti (n1, -1));
      r0 = si_selb (r0, r1, mask);
      n0 = si_selb (n0, n1, mask);
      bit = si_rotqmbii (bit, -1);
      d0 = si_rotqmbii (d0, -1);
    }
  while (si_to_uint (si_orx (bit)));
  if (rp)
    *rp = si_to_UTItype (n0);
  return si_to_UTItype (r0);
}
Example #21
0
int
mpfr_set_si (mpfr_ptr x, long i, mp_rnd_t rnd_mode)
{
  int inex;
  mp_size_t xn;
  unsigned int cnt, nbits;
  mp_limb_t ai, *xp;

  MPFR_CLEAR_FLAGS(x);
  if (i == 0)
    {
      MPFR_SET_ZERO(x);
      MPFR_SET_POS(x);
      MPFR_RET(0);
    }

  xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
  ai = SAFE_ABS(long, i);
  count_leading_zeros(cnt, ai);

  xp = MPFR_MANT(x);
  xp[xn] = ai << cnt;
  /* don't forget to put zero in lower limbs */
  MPN_ZERO(xp, xn);
  /* set sign */
  if ((i < 0) ^ (MPFR_SIGN(x) < 0))
    MPFR_CHANGE_SIGN(x);

  MPFR_EXP(x) = nbits = BITS_PER_MP_LIMB - cnt;
  inex = mpfr_check_range(x, rnd_mode);
  if (inex)
    return inex; /* underflow or overflow */

  /* round if MPFR_PREC(x) smaller than length of i */
  if (MPFR_PREC(x) < nbits)
    {
      int carry;

      carry = mpfr_round_raw(xp+xn, xp+xn, nbits, (i < 0), MPFR_PREC(x),
                             rnd_mode, &inex);
      if (carry)
        {
          mp_exp_t exp = MPFR_EXP(x);

          if (exp == __mpfr_emax)
            return mpfr_set_overflow(x, rnd_mode, (i < 0 ? -1 : 1));

          MPFR_EXP(x)++;
          xp[xn] = GMP_LIMB_HIGHBIT;
        }
    }

  MPFR_RET(inex);
}
Example #22
0
int
mpfr_ui_div (mpfr_ptr y, unsigned long int u, mpfr_srcptr x, mp_rnd_t rnd_mode)
{
  mpfr_t uu;
  mp_limb_t up[1];
  unsigned long cnt;

  if (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x)))
    {
      if (MPFR_IS_NAN(x))
        {
          MPFR_SET_NAN(y);
          MPFR_RET_NAN;
        }
      else if (MPFR_IS_INF(x)) /* u/Inf = 0 */
        {
          MPFR_SET_ZERO(y);
          MPFR_SET_SAME_SIGN(y,x);
          MPFR_RET(0);
        }
      else /* u / 0 */
        {
          MPFR_ASSERTD(MPFR_IS_ZERO(x));
          if (u)
            {
              /* u > 0, so y = sign(x) * Inf */
              MPFR_SET_SAME_SIGN(y, x);
              MPFR_SET_INF(y);
              MPFR_RET(0);
            }
          else
            {
              /* 0 / 0 */
              MPFR_SET_NAN(y);
              MPFR_RET_NAN;
            }
        }
    }
  else if (MPFR_LIKELY(u != 0))
    {
      MPFR_TMP_INIT1(up, uu, BITS_PER_MP_LIMB);
      MPFR_ASSERTN(u == (mp_limb_t) u);
      count_leading_zeros(cnt, (mp_limb_t) u);
      up[0] = (mp_limb_t) u << cnt;
      MPFR_SET_EXP (uu, BITS_PER_MP_LIMB - cnt);
      return mpfr_div (y, uu, x, rnd_mode);
    }
  else /* u = 0, and x != 0 */
    {
      MPFR_SET_ZERO(y);         /* if u=0, then set y to 0 */
      MPFR_SET_SAME_SIGN(y, x); /* u considered as +0: sign(+0/x) = sign(x) */
      MPFR_RET(0);
    }
}
Example #23
0
mp_size_t
mpn_hgcd_step (mp_size_t n, mp_ptr ap, mp_ptr bp, mp_size_t s,
	       struct hgcd_matrix *M, mp_ptr tp)
{
  struct hgcd_matrix1 M1;
  mp_limb_t mask;
  mp_limb_t ah, al, bh, bl;

  ASSERT (n > s);

  mask = ap[n-1] | bp[n-1];
  ASSERT (mask > 0);

  if (n == s + 1)
    {
      if (mask < 4)
	goto subtract;

      ah = ap[n-1]; al = ap[n-2];
      bh = bp[n-1]; bl = bp[n-2];
    }
  else if (mask & GMP_NUMB_HIGHBIT)
    {
      ah = ap[n-1]; al = ap[n-2];
      bh = bp[n-1]; bl = bp[n-2];
    }
  else
    {
      int shift;

      count_leading_zeros (shift, mask);
      ah = MPN_EXTRACT_NUMB (shift, ap[n-1], ap[n-2]);
      al = MPN_EXTRACT_NUMB (shift, ap[n-2], ap[n-3]);
      bh = MPN_EXTRACT_NUMB (shift, bp[n-1], bp[n-2]);
      bl = MPN_EXTRACT_NUMB (shift, bp[n-2], bp[n-3]);
    }

  /* Try an mpn_hgcd2 step */
  if (mpn_hgcd2 (ah, al, bh, bl, &M1))
    {
      /* Multiply M <- M * M1 */
      mpn_hgcd_matrix_mul_1 (M, &M1, tp);

      /* Can't swap inputs, so we need to copy. */
      MPN_COPY (tp, ap, n);
      /* Multiply M1^{-1} (a;b) */
      return mpn_matrix22_mul1_inverse_vector (&M1, ap, tp, bp, n);
    }

 subtract:

  return mpn_gcd_subdiv_step (ap, bp, n, s, hgcd_hook, M, tp);
}
Example #24
0
/* set f to the integer z */
int 
mpfr_set_z (mpfr_ptr f, mpz_srcptr z, mp_rnd_t rnd_mode)
{
  mp_size_t fn, zn, dif;
  int k, sign_z, inex;
  mp_limb_t *fp, *zp;
  mp_exp_t exp;

  MPFR_CLEAR_FLAGS (f); /* z cannot be NaN nor Inf */

  sign_z = mpz_cmp_ui (z, 0);

  if (sign_z == 0)
    {
      MPFR_SET_ZERO(f);
      MPFR_SET_POS(f);
      MPFR_RET(0);
    }

  fp = MPFR_MANT(f);
  fn = 1 + (MPFR_PREC(f) - 1) / BITS_PER_MP_LIMB;
  zn = ABS(SIZ(z));
  dif = zn - fn;
  zp = PTR(z);
  count_leading_zeros(k, zp[zn-1]);

  exp = (mp_prec_t) zn * BITS_PER_MP_LIMB - k;
  /* The exponent will be exp or exp + 1 (due to rounding) */
  if (exp > __mpfr_emax)
    return mpfr_set_overflow(f, rnd_mode, sign_z);
  if (exp + 1 < __mpfr_emin)
    return mpfr_set_underflow(f, rnd_mode, sign_z);

  if (MPFR_SIGN(f) * sign_z < 0)
    MPFR_CHANGE_SIGN(f);

  if (dif >= 0)
    {
      mp_limb_t cc;
      int sh;

      /* number has to be truncated */
      if (k != 0)
        {
          mpn_lshift(fp, zp + dif, fn, k);
          if (dif != 0)
            fp[0] += zp[dif - 1] >> (BITS_PER_MP_LIMB - k);
        }
Example #25
0
int
mpfr_set_si_2exp (mpfr_ptr x, long i, mp_exp_t e, mp_rnd_t rnd_mode)
{
  if (i == 0)
    {
      MPFR_SET_ZERO (x);
      MPFR_SET_POS (x);
      MPFR_RET (0);
    }
  else
    {
      mp_size_t xn;
      unsigned int cnt, nbits;
      mp_limb_t ai, *xp;
      int inex = 0;

      /* FIXME: support int limbs (e.g. 16-bit limbs on 16-bit proc) */
      ai = SAFE_ABS (unsigned long, i);
      MPFR_ASSERTN (SAFE_ABS (unsigned long, i) == ai);

      /* Position of the highest limb */
      xn = (MPFR_PREC (x) - 1) / BITS_PER_MP_LIMB;
      count_leading_zeros (cnt, ai);
      MPFR_ASSERTD (cnt < BITS_PER_MP_LIMB);  /* OK since i != 0 */

      xp = MPFR_MANT(x);
      xp[xn] = ai << cnt;
      /* Zero the xn lower limbs. */
      MPN_ZERO(xp, xn);
      MPFR_SET_SIGN (x, i < 0 ? MPFR_SIGN_NEG : MPFR_SIGN_POS);

      nbits = BITS_PER_MP_LIMB - cnt;
      e += nbits;  /* exponent _before_ the rounding */

      /* round if MPFR_PREC(x) smaller than length of i */
      if (MPFR_UNLIKELY (MPFR_PREC (x) < nbits) &&
          MPFR_UNLIKELY (mpfr_round_raw (xp + xn, xp + xn, nbits, i < 0,
                                         MPFR_PREC (x), rnd_mode, &inex)))
        {
          e++;
          xp[xn] = MPFR_LIMB_HIGHBIT;
        }

      MPFR_CLEAR_FLAGS (x);
      MPFR_EXP (x) = e;
      return mpfr_check_range (x, inex, rnd_mode);
    }
}
Example #26
0
std::pair<Interval::uint64, int> CodeInterval::normalize() noexcept
{
	const uint64 bits = base;
	if(range == 0) {
		base = 0;
		range = max;
		return {bits, 64};
	} else {
		const int n = count_leading_zeros(range);
		base <<= n;
		range <<= n;
		range |= (1UL << n) - 1UL;
		assert(range >= msb);
		return {bits, n};
	}
}
Example #27
0
static int count_lzeros(MPI a)
{
	mpi_limb_t alimb;
	int i, lzeros = 0;

	for (i = a->nlimbs - 1; i >= 0; i--) {
		alimb = a->d[i];
		if (alimb == 0) {
			lzeros += sizeof(mpi_limb_t);
		} else {
			lzeros += count_leading_zeros(alimb) / 8;
			break;
		}
	}
	return lzeros;
}
Example #28
0
/**
 * mpi_read_raw_data - Read a raw byte stream as a positive integer
 * @xbuffer: The data to read
 * @nbytes: The amount of data to read
 */
MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes)
{
	const uint8_t *buffer = xbuffer;
	int i, j;
	unsigned nbits, nlimbs;
	mpi_limb_t a;
	MPI val = NULL;

	while (nbytes > 0 && buffer[0] == 0) {
		buffer++;
		nbytes--;
	}

	nbits = nbytes * 8;
	if (nbits > MAX_EXTERN_MPI_BITS) {
		pr_info("MPI: mpi too large (%u bits)\n", nbits);
		return NULL;
	}
	if (nbytes > 0)
		nbits -= count_leading_zeros(buffer[0]);
	else
		nbits = 0;

	nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB);
	val = mpi_alloc(nlimbs);
	if (!val)
		return NULL;
	val->nbits = nbits;
	val->sign = 0;
	val->nlimbs = nlimbs;

	if (nbytes > 0) {
		i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
		i %= BYTES_PER_MPI_LIMB;
		for (j = nlimbs; j > 0; j--) {
			a = 0;
			for (; i < BYTES_PER_MPI_LIMB; i++) {
				a <<= 8;
				a |= *buffer++;
			}
			i = 0;
			val->d[j - 1] = a;
		}
	}
	return val;
}
int
mpfr_set_ui_2exp (mpfr_ptr x, unsigned long i, mpfr_exp_t e, mpfr_rnd_t rnd_mode)
{
  MPFR_SET_POS (x);

  if (i == 0)
    {
      MPFR_SET_ZERO (x);
      MPFR_RET (0);
    }
  else
    {
      mp_size_t xn;
      unsigned int cnt, nbits;
      mp_limb_t *xp;
      int inex = 0;

      /* FIXME: support int limbs (e.g. 16-bit limbs on 16-bit proc) */
      MPFR_ASSERTD (i == (mp_limb_t) i);

      /* Position of the highest limb */
      xn = (MPFR_PREC (x) - 1) / GMP_NUMB_BITS;
      count_leading_zeros (cnt, (mp_limb_t) i);
      MPFR_ASSERTD (cnt < GMP_NUMB_BITS);  /* OK since i != 0 */

      xp = MPFR_MANT(x);
      xp[xn] = ((mp_limb_t) i) << cnt;
      /* Zero the xn lower limbs. */
      MPN_ZERO(xp, xn);

      nbits = GMP_NUMB_BITS - cnt;
      e += nbits;  /* exponent _before_ the rounding */

      /* round if MPFR_PREC(x) smaller than length of i */
      if (MPFR_UNLIKELY (MPFR_PREC (x) < nbits) &&
          MPFR_UNLIKELY (mpfr_round_raw (xp + xn, xp + xn, nbits, 0,
                                         MPFR_PREC (x), rnd_mode, &inex)))
        {
          e++;
          xp[xn] = MPFR_LIMB_HIGHBIT;
        }

      MPFR_EXP (x) = e;
      return mpfr_check_range (x, inex, rnd_mode);
    }
}
Example #30
0
int
__gmpfr_int_ceil_log2 (unsigned long n)
{
  if (MPFR_UNLIKELY (n == 1))
    return 0;
  else
    {
      int b;
      mp_limb_t limb;

      MPFR_ASSERTN (n > 1);
      limb = n - 1;
      MPFR_ASSERTN (limb == n - 1);
      count_leading_zeros (b, limb);
      return GMP_NUMB_BITS - b;
    }
}