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C++ MPFR_EXP函数代码示例

原作者: [db:作者] 来自: [db:来源] 收藏 邀请

本文整理汇总了C++中MPFR_EXP函数的典型用法代码示例。如果您正苦于以下问题:C++ MPFR_EXP函数的具体用法?C++ MPFR_EXP怎么用?C++ MPFR_EXP使用的例子?那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。



在下文中一共展示了MPFR_EXP函数的20个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于我们的系统推荐出更棒的C++代码示例。

示例1: mpfr_yn_s1

/* compute in s an approximation of S1 = sum((n-k)!/k!*y^k,k=0..n)
   return e >= 0 the exponent difference between the maximal value of |s|
   during the for loop and the final value of |s|.
*/
static mp_exp_t
mpfr_yn_s1 (mpfr_ptr s, mpfr_srcptr y, unsigned long n)
{
  unsigned long k;
  mpz_t f;
  mp_exp_t e, emax;

  mpz_init_set_ui (f, 1);
  /* we compute n!*S1 = sum(a[k]*y^k,k=0..n) where a[k] = n!*(n-k)!/k!,
     a[0] = (n!)^2, a[1] = n!*(n-1)!, ..., a[n-1] = n, a[n] = 1 */
  mpfr_set_ui (s, 1, GMP_RNDN); /* a[n] */
  emax = MPFR_EXP(s);
  for (k = n; k-- > 0;)
    {
      /* a[k]/a[k+1] = (n-k)!/k!/(n-(k+1))!*(k+1)! = (k+1)*(n-k) */
      mpfr_mul (s, s, y, GMP_RNDN);
      mpz_mul_ui (f, f, n - k);
      mpz_mul_ui (f, f, k + 1);
      /* invariant: f = a[k] */
      mpfr_add_z (s, s, f, GMP_RNDN);
      e = MPFR_EXP(s);
      if (e > emax)
        emax = e;
    }
  /* now we have f = (n!)^2 */
  mpz_sqrt (f, f);
  mpfr_div_z (s, s, f, GMP_RNDN);
  mpz_clear (f);
  return emax - MPFR_EXP(s);
}
开发者ID:Scorpiion,项目名称:Renux_cross_gcc,代码行数:34,代码来源:yn.c


示例2: mpfr_add_one_ulp

/* sets x to x+sign(x)*ulp(x) */
int
mpfr_add_one_ulp (mpfr_ptr x, mp_rnd_t rnd_mode)
{
  mp_size_t xn;
  int sh;
  mp_limb_t *xp;

  if (MPFR_IS_NAN(x))
    MPFR_RET_NAN;

  if (MPFR_IS_INF(x) || MPFR_IS_ZERO(x))
    return 0;

  xn = 1 + (MPFR_PREC(x) - 1) / BITS_PER_MP_LIMB;
  sh = xn * BITS_PER_MP_LIMB - MPFR_PREC(x);
  xp = MPFR_MANT(x);
  if (mpn_add_1 (xp, xp, xn, MP_LIMB_T_ONE << sh)) /* got 1.0000... */
    {
      mp_exp_t exp = MPFR_EXP(x);
      if (exp == __mpfr_emax)
        return mpfr_set_overflow(x, rnd_mode, MPFR_SIGN(x));
      else
        {
          MPFR_EXP(x)++;
          xp[xn-1] = GMP_LIMB_HIGHBIT;
        }
    }
  return 0;
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:30,代码来源:add_one_ulp.c


示例3: Li2

/* try asymptotic expansion when x is large and negative:
   Li2(x) = -log(-x)^2/2 - Pi^2/6 - 1/x + O(1/x^2).
   More precisely for x <= -2 we have for g(x) = -log(-x)^2/2 - Pi^2/6:
   |Li2(x) - g(x)| <= 1/|x|.
   Assumes x <= -7, which ensures |log(-x)^2/2| >= Pi^2/6, and g(x) <= -3.5.
   Return 0 if asymptotic expansion failed (unable to round), otherwise
   returns correct ternary value.
*/
static int
mpfr_li2_asympt_neg (mpfr_ptr y, mpfr_srcptr x, mpfr_rnd_t rnd_mode)
{
  mpfr_t g, h;
  mp_prec_t w = MPFR_PREC (y) + 20;
  int inex = 0;

  MPFR_ASSERTN (mpfr_cmp_si (x, -7) <= 0);

  mpfr_init2 (g, w);
  mpfr_init2 (h, w);
  mpfr_neg (g, x, GMP_RNDN);
  mpfr_log (g, g, GMP_RNDN);    /* rel. error <= |(1 + theta) - 1| */
  mpfr_sqr (g, g, GMP_RNDN);    /* rel. error <= |(1 + theta)^3 - 1| <= 2^(2-w) */
  mpfr_div_2ui (g, g, 1, GMP_RNDN);     /* rel. error <= 2^(2-w) */
  mpfr_const_pi (h, GMP_RNDN);  /* error <= 2^(1-w) */
  mpfr_sqr (h, h, GMP_RNDN);    /* rel. error <= 2^(2-w) */
  mpfr_div_ui (h, h, 6, GMP_RNDN);      /* rel. error <= |(1 + theta)^4 - 1|
                                           <= 5 * 2^(-w) */
  MPFR_ASSERTN (MPFR_EXP (g) >= MPFR_EXP (h));
  mpfr_add (g, g, h, GMP_RNDN); /* err <= ulp(g)/2 + g*2^(2-w) + g*5*2^(-w)
                                   <= ulp(g) * (1/2 + 4 + 5) < 10 ulp(g).

                                   If in addition |1/x| <= 4 ulp(g), then the
                                   total error is bounded by 16 ulp(g). */
  if ((MPFR_EXP (x) >= (mp_exp_t) (w - 2) - MPFR_EXP (g)) &&
      MPFR_CAN_ROUND (g, w - 4, MPFR_PREC (y), rnd_mode))
    inex = mpfr_neg (y, g, rnd_mode);

  mpfr_clear (g);
  mpfr_clear (h);

  return inex;
}
开发者ID:Scorpiion,项目名称:Renux_cross_gcc,代码行数:42,代码来源:li2.c


示例4: mpc_norm

/* the rounding mode is mpfr_rnd_t here since we return an mpfr number */
int
mpc_norm (mpfr_ptr a, mpc_srcptr b, mpfr_rnd_t rnd)
{
    mpfr_t u, v;
    mp_prec_t prec;
    int inexact, overflow;

    prec = MPFR_PREC(a);

    /* handling of special values; consistent with abs in that
       norm = abs^2; so norm (+-inf, nan) = norm (nan, +-inf) = +inf */
    if (   (mpfr_nan_p (MPC_RE (b)) || mpfr_nan_p (MPC_IM (b)))
            || (mpfr_inf_p (MPC_RE (b)) || mpfr_inf_p (MPC_IM (b))))
        return mpc_abs (a, b, rnd);

    mpfr_init (u);
    mpfr_init (v);

    if (!mpfr_zero_p(MPC_RE(b)) && !mpfr_zero_p(MPC_IM(b)) &&
            2 * SAFE_ABS (mp_exp_t, MPFR_EXP (MPC_RE (b)) - MPFR_EXP (MPC_IM (b)))
            > (mp_exp_t)prec)
        /* If real and imaginary part have very different magnitudes, then the */
        /* generic code increases the precision too much. Instead, compute the */
        /* squarings _exactly_.                                                */
    {
        mpfr_set_prec (u, 2 * MPFR_PREC (MPC_RE (b)));
        mpfr_set_prec (v, 2 * MPFR_PREC (MPC_IM (b)));
        mpfr_sqr (u, MPC_RE (b), GMP_RNDN);
        mpfr_sqr (v, MPC_IM (b), GMP_RNDN);
        inexact = mpfr_add (a, u, v, rnd);
    }
    else
    {
        do
        {
            prec += mpc_ceil_log2 (prec) + 3;

            mpfr_set_prec (u, prec);
            mpfr_set_prec (v, prec);

            inexact = mpfr_sqr (u, MPC_RE(b), GMP_RNDN);  /* err<=1/2ulp */
            inexact |= mpfr_sqr (v, MPC_IM(b), GMP_RNDN); /* err<=1/2ulp*/
            inexact |= mpfr_add (u, u, v, GMP_RNDN);      /* err <= 3/2 ulps */

            overflow = mpfr_inf_p (u);
        }
        while (!overflow && inexact &&
                mpfr_can_round (u, prec - 2, GMP_RNDN, rnd, MPFR_PREC(a)) == 0);

        inexact |= mpfr_set (a, u, rnd);
    }
    mpfr_clear (u);
    mpfr_clear (v);

    return inexact;
}
开发者ID:fabio-d,项目名称:xc16plusplus-source,代码行数:57,代码来源:norm.c


示例5: mpfr_const_euler_internal

int
mpfr_const_euler_internal (mpfr_t x, mpfr_rnd_t rnd)
{
  mpfr_prec_t prec = MPFR_PREC(x), m, log2m;
  mpfr_t y, z;
  unsigned long n;
  int inexact;
  MPFR_ZIV_DECL (loop);

  log2m = MPFR_INT_CEIL_LOG2 (prec);
  m = prec + 2 * log2m + 23;

  mpfr_init2 (y, m);
  mpfr_init2 (z, m);

  MPFR_ZIV_INIT (loop, m);
  for (;;)
    {
      mpfr_exp_t exp_S, err;
      /* since prec >= 1, we have m >= 24 here, which ensures n >= 9 below */
      n = 1 + (unsigned long) ((double) m * LOG2 / 2.0);
      MPFR_ASSERTD (n >= 9);
      mpfr_const_euler_S2 (y, n); /* error <= 3 ulps */
      exp_S = MPFR_EXP(y);
      mpfr_set_ui (z, n, MPFR_RNDN);
      mpfr_log (z, z, MPFR_RNDD); /* error <= 1 ulp */
      mpfr_sub (y, y, z, MPFR_RNDN); /* S'(n) - log(n) */
      /* the error is less than 1/2 + 3*2^(exp_S-EXP(y)) + 2^(EXP(z)-EXP(y))
         <= 1/2 + 2^(exp_S+2-EXP(y)) + 2^(EXP(z)-EXP(y))
         <= 1/2 + 2^(1+MAX(exp_S+2,EXP(z))-EXP(y)) */
      err = 1 + MAX(exp_S + 2, MPFR_EXP(z)) - MPFR_EXP(y);
      err = (err >= -1) ? err + 1 : 0; /* error <= 2^err ulp(y) */
      exp_S = MPFR_EXP(y);
      mpfr_const_euler_R (z, n); /* err <= ulp(1/2) = 2^(-m) */
      mpfr_sub (y, y, z, MPFR_RNDN);
      /* err <= 1/2 ulp(y) + 2^(-m) + 2^(err + exp_S - EXP(y)) ulp(y).
         Since the result is between 0.5 and 1, ulp(y) = 2^(-m).
         So we get 3/2*ulp(y) + 2^(err + exp_S - EXP(y)) ulp(y).
         3/2 + 2^e <= 2^(e+1) for e>=1, and <= 2^2 otherwise */
      err = err + exp_S - MPFR_EXP(y);
      err = (err >= 1) ? err + 1 : 2;
      if (MPFR_LIKELY (MPFR_CAN_ROUND (y, m - err, prec, rnd)))
        break;
      MPFR_ZIV_NEXT (loop, m);
      mpfr_set_prec (y, m);
      mpfr_set_prec (z, m);
    }
  MPFR_ZIV_FREE (loop);

  inexact = mpfr_set (x, y, rnd);

  mpfr_clear (y);
  mpfr_clear (z);

  return inexact; /* always inexact */
}
开发者ID:119,项目名称:aircam-openwrt,代码行数:56,代码来源:const_euler.c


示例6: mpfr_set_si

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);
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:54,代码来源:set_si.c


示例7: mpfr_check

/*
 * Check if x is a valid mpfr_t initializes by mpfr_init
 * Returns 0 if isn't valid
 */
int
mpfr_check (mpfr_srcptr x)
{
  mp_size_t s, i;
  mp_limb_t tmp;
  volatile mp_limb_t *xm;
  mpfr_prec_t prec;
  int rw;

  /* Check sign */
  if (MPFR_SIGN(x) != MPFR_SIGN_POS &&
      MPFR_SIGN(x) != MPFR_SIGN_NEG)
    return 0;
  /* Check precision */
  prec = MPFR_PREC(x);
  if (prec < MPFR_PREC_MIN ||
      prec > MPFR_PREC_MAX)
    return 0;
  /* Check mantissa */
  xm = MPFR_MANT(x);
  if (xm == NULL)
    return 0;
  /* Check size of mantissa */
  s = MPFR_GET_ALLOC_SIZE(x);
  if (s <= 0 || s > MP_SIZE_T_MAX ||
      prec > (mpfr_prec_t) s * GMP_NUMB_BITS)
    return 0;
  /* Acces all the mp_limb of the mantissa: may do a seg fault */
  for (i = 0 ; i < s ; i++)
    tmp = xm[i];
  /* Check singular numbers (do not use MPFR_IS_PURE_FP() in order to avoid
     any assertion checking, as this function mpfr_check() does something
     similar by returning a Boolean instead of doing an abort if the format
     is incorrect). */
  if (MPFR_IS_SINGULAR (x))
    return MPFR_IS_ZERO(x) || MPFR_IS_NAN(x) || MPFR_IS_INF(x);
  /* Check the most significant limb (its MSB must be 1) */
  if ((xm[MPFR_LAST_LIMB(x)] & MPFR_LIMB_HIGHBIT) == 0)
    return 0;
  /* Check the least significant limb (the trailing bits must be 0) */
  rw = prec % GMP_NUMB_BITS;
  if (rw != 0)
    {
      tmp = MPFR_LIMB_MASK (GMP_NUMB_BITS - rw);
      if ((xm[0] & tmp) != 0)
        return 0;
    }
  /* Check exponent range */
  if (MPFR_EXP (x) < __gmpfr_emin ||
      MPFR_EXP (x) > __gmpfr_emax)
    return 0;
  return 1;
}
开发者ID:epowers,项目名称:mpfr,代码行数:57,代码来源:check.c


示例8: numbers

/* return non zero iff x^y is exact.
   Assumes x and y are ordinary numbers (neither NaN nor Inf),
   and y is not zero.
*/
int
mpfr_pow_is_exact (mpfr_srcptr x, mpfr_srcptr y)
{
  mp_exp_t d;
  unsigned long i, c;
  mp_limb_t *yp;
  
  if ((mpfr_sgn (x) < 0) && (mpfr_isinteger (y) == 0))
      return 0;

  if (mpfr_sgn (y) < 0)
    return mpfr_cmp_si_2exp (x, MPFR_SIGN(x), MPFR_EXP(x) - 1) == 0;

  /* compute d such that y = c*2^d with c odd integer */
  d = MPFR_EXP(y) - MPFR_PREC(y);
  /* since y is not zero, necessarily one of the mantissa limbs is not zero,
     thus we can simply loop until we find a non zero limb */
  yp = MPFR_MANT(y);
  for (i = 0; yp[i] == 0; i++, d += BITS_PER_MP_LIMB);
  /* now yp[i] is not zero */
  count_trailing_zeros (c, yp[i]);
  d += c;
  
  if (d < 0)
    {
      mpz_t a;
      mp_exp_t b;

      mpz_init (a);
      b = mpfr_get_z_exp (a, x); /* x = a * 2^b */
      c = mpz_scan1 (a, 0);
      mpz_div_2exp (a, a, c);
      b += c;
      /* now a is odd */
      while (d != 0)
        {
          if (mpz_perfect_square_p (a))
            {
              d++;
              mpz_sqrt (a, a);
            }
          else
            {
              mpz_clear (a);
              return 0;
            }
        }
      mpz_clear (a);
    }

    return 1;
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:56,代码来源:pow.c


示例9: mpfr_set_underflow

int
mpfr_set_underflow (mpfr_ptr x, mp_rnd_t rnd_mode, int sign)
{
  int inex;

  MPFR_CLEAR_FLAGS(x);
  if ((rnd_mode == GMP_RNDU && sign > 0)
   || (rnd_mode == GMP_RNDD && sign < 0))
    {
      mp_size_t xn;
      mp_limb_t *xp;

      MPFR_EXP(x) = __mpfr_emin;
      xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
      xp = MPFR_MANT(x);
      xp[xn] = GMP_LIMB_HIGHBIT;
      MPN_ZERO(xp, xn);
      inex = 1;
    }
  else
    {
      MPFR_SET_ZERO(x);
      inex = -1;
    }
  if (MPFR_SIGN(x) != sign)
    MPFR_CHANGE_SIGN(x);
  __mpfr_flags |= MPFR_FLAGS_INEXACT | MPFR_FLAGS_UNDERFLOW;
  return sign > 0 ? inex : -inex;
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:29,代码来源:exceptions.c


示例10: mpfr_custom_init_set

void
mpfr_custom_init_set (mpfr_ptr x, int kind, mp_exp_t exp,
                     mp_prec_t prec, void *mantissa)
{
  mpfr_kind_t t;
  int s;
  mp_exp_t e;

  if (kind >= 0)
    {
      t = (mpfr_kind_t) kind;
      s = MPFR_SIGN_POS;
    }
  else
    {
      t = (mpfr_kind_t) -kind;
      s = MPFR_SIGN_NEG;
    }
  MPFR_ASSERTD (t <= MPFR_REGULAR_KIND);
  e = MPFR_LIKELY (t == MPFR_REGULAR_KIND) ? exp :
    MPFR_UNLIKELY (t == MPFR_NAN_KIND) ? MPFR_EXP_NAN :
    MPFR_UNLIKELY (t == MPFR_INF_KIND) ? MPFR_EXP_INF : MPFR_EXP_ZERO;

  MPFR_PREC (x) = prec;
  MPFR_SET_SIGN (x, s);
  MPFR_EXP (x) = e;
  MPFR_MANT (x) = (mp_limb_t*) mantissa;
  return;
}
开发者ID:STAR111,项目名称:GCC_parser,代码行数:29,代码来源:stack_interface.c


示例11: mpfr_random2

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);
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:32,代码来源:random2.c


示例12: mpfr_check_range

int
mpfr_check_range (mpfr_ptr x, int t, mp_rnd_t rnd_mode)
{
  if (MPFR_LIKELY( MPFR_IS_PURE_FP(x)) )
    { /* x is a non-zero FP */
      mp_exp_t exp = MPFR_EXP (x);  /* Do not use MPFR_GET_EXP */
      if (MPFR_UNLIKELY( exp < __gmpfr_emin) )
        {
          /* The following test is necessary because in the rounding to the
           * nearest mode, mpfr_underflow always rounds away from 0. In
           * this rounding mode, we need to round to 0 if:
           *   _ |x| < 2^(emin-2), or
           *   _ |x| = 2^(emin-2) and the absolute value of the exact
           *     result is <= 2^(emin-2).
           */
          if (rnd_mode == GMP_RNDN &&
              (exp + 1 < __gmpfr_emin ||
               (mpfr_powerof2_raw(x) &&
                (MPFR_IS_NEG(x) ? t <= 0 : t >= 0))))
            rnd_mode = GMP_RNDZ;
          return mpfr_underflow(x, rnd_mode, MPFR_SIGN(x));
        }
      if (MPFR_UNLIKELY( exp > __gmpfr_emax) )
        return mpfr_overflow(x, rnd_mode, MPFR_SIGN(x));
    }
  MPFR_RET (t);  /* propagate inexact ternary value, unlike most functions */
}
开发者ID:mmanley,项目名称:Antares,代码行数:27,代码来源:exceptions.c


示例13: mpfr_set_overflow

int
mpfr_set_overflow (mpfr_ptr x, mp_rnd_t rnd_mode, int sign)
{
  int inex;

  MPFR_CLEAR_FLAGS(x);
  if ((rnd_mode == GMP_RNDU && sign < 0)
   || (rnd_mode == GMP_RNDD && sign > 0))
    {
      mp_size_t xn, i;
      int sh;
      mp_limb_t *xp;

      MPFR_EXP(x) = __mpfr_emax;
      xn = 1 + (MPFR_PREC(x) - 1) / BITS_PER_MP_LIMB;
      sh = xn * BITS_PER_MP_LIMB - MPFR_PREC(x);
      xp = MPFR_MANT(x);
      xp[0] = MP_LIMB_T_MAX << sh;
      for (i = 1; i < xn; i++)
        xp[i] = MP_LIMB_T_MAX;
      inex = -1;
    }
  else
    {
      MPFR_SET_INF(x);
      inex = 1;
    }
  if (MPFR_SIGN(x) != sign)
    MPFR_CHANGE_SIGN(x);
  __mpfr_flags |= MPFR_FLAGS_INEXACT | MPFR_FLAGS_OVERFLOW;
  return sign > 0 ? inex : -inex;
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:32,代码来源:exceptions.c


示例14: mpfr_add_ui

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);
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:25,代码来源:add_ui.c


示例15: mpfr_check_range

int
mpfr_check_range (mpfr_ptr x, int t, mpfr_rnd_t rnd_mode)
{
  if (MPFR_LIKELY( MPFR_IS_PURE_FP(x)) )
    { /* x is a non-zero FP */
      mpfr_exp_t exp = MPFR_EXP (x);  /* Do not use MPFR_GET_EXP */
      /* Even if it is unlikely that exp is lower than emin,
         this function is called by MPFR functions only if it is
         already the case (or if exp is greater than emax) */
      if (exp < __gmpfr_emin)
        {
          /* The following test is necessary because in the rounding to the
           * nearest mode, mpfr_underflow always rounds away from 0. In
           * this rounding mode, we need to round to 0 if:
           *   _ |x| < 2^(emin-2), or
           *   _ |x| = 2^(emin-2) and the absolute value of the exact
           *     result is <= 2^(emin-2).
           */
          if (rnd_mode == MPFR_RNDN &&
              (exp + 1 < __gmpfr_emin ||
               (mpfr_powerof2_raw(x) &&
                (MPFR_IS_NEG(x) ? t <= 0 : t >= 0))))
            rnd_mode = MPFR_RNDZ;
          return mpfr_underflow(x, rnd_mode, MPFR_SIGN(x));
        }
      if (exp > __gmpfr_emax)
        return mpfr_overflow (x, rnd_mode, MPFR_SIGN(x));
    }
  else if (MPFR_UNLIKELY (t != 0 && MPFR_IS_INF (x)))
    {
      /* We need to do the following because most MPFR functions are
       * implemented in the following way:
       *   Ziv's loop:
       *   | Compute an approximation to the result and an error bound.
       *   | Possible underflow/overflow detection -> return.
       *   | If can_round, break (exit the loop).
       *   | Otherwise, increase the working precision and loop.
       *   Round the approximation in the target precision.  <== See below
       *   Restore the flags (that could have been set due to underflows
       *   or overflows during the internal computations).
       *   Execute: return mpfr_check_range (...).
       * The problem is that an overflow could be generated when rounding the
       * approximation (in general, such an overflow could not be detected
       * earlier), and the overflow flag is lost when the flags are restored.
       * This can occur only when the rounding yields an exponent change
       * and the new exponent is larger than the maximum exponent, so that
       * an infinity is necessarily obtained.
       * So, the simplest solution is to detect this overflow case here in
       * mpfr_check_range, which is easy to do since the rounded result is
       * necessarily an inexact infinity.
       */
      __gmpfr_flags |= MPFR_FLAGS_OVERFLOW;
    }
  MPFR_RET (t);  /* propagate inexact ternary value, unlike most functions */
}
开发者ID:cmjonze,项目名称:mpfr,代码行数:55,代码来源:exceptions.c


示例16: check_set_uj

static void
check_set_uj (mpfr_prec_t pmin, mpfr_prec_t pmax, int N)
{
    mpfr_t x, y;
    mpfr_prec_t p;
    int inex1, inex2, n;
    mp_limb_t limb;

    mpfr_inits2 (pmax, x, y, (mpfr_ptr) 0);

    for ( p = pmin ; p < pmax ; p++)
    {
        mpfr_set_prec (x, p);
        mpfr_set_prec (y, p);
        for (n = 0 ; n < N ; n++)
        {
            /* mp_limb_t may be unsigned long long */
            limb = (unsigned long) randlimb ();
            inex1 = mpfr_set_uj (x, limb, MPFR_RNDN);
            inex2 = mpfr_set_ui (y, limb, MPFR_RNDN);
            if (mpfr_cmp (x, y))
            {
                printf ("ERROR for mpfr_set_uj and j=%lu and p=%lu\n",
                        (unsigned long) limb, (unsigned long) p);
                printf ("X=");
                mpfr_dump (x);
                printf ("Y=");
                mpfr_dump (y);
                exit (1);
            }
            if (inexact_sign (inex1) != inexact_sign (inex2))
            {
                printf ("ERROR for inexact(set_uj): j=%lu p=%lu\n"
                        "Inexact1= %d Inexact2= %d\n",
                        (unsigned long) limb, (unsigned long) p, inex1, inex2);
                exit (1);
            }
        }
    }
    /* Special case */
    mpfr_set_prec (x, sizeof(uintmax_t)*CHAR_BIT);
    inex1 = mpfr_set_uj (x, MPFR_UINTMAX_MAX, MPFR_RNDN);
    if (inex1 != 0 || mpfr_sgn(x) <= 0)
        ERROR ("inexact / UINTMAX_MAX");
    inex1 = mpfr_add_ui (x, x, 1, MPFR_RNDN);
    if (inex1 != 0 || !mpfr_powerof2_raw (x)
            || MPFR_EXP (x) != (sizeof(uintmax_t)*CHAR_BIT+1) )
        ERROR ("power of 2");
    mpfr_set_uj (x, 0, MPFR_RNDN);
    if (!MPFR_IS_ZERO (x))
        ERROR ("Setting 0");

    mpfr_clears (x, y, (mpfr_ptr) 0);
}
开发者ID:qsnake,项目名称:mpfr,代码行数:54,代码来源:tset_sj.c


示例17: mpfr_set_exp

int
mpfr_set_exp (mpfr_ptr x, mpfr_exp_t exponent)
{
  if (exponent >= __gmpfr_emin && exponent <= __gmpfr_emax)
    {
      MPFR_EXP(x) = exponent; /* do not use MPFR_SET_EXP of course... */
      return 0;
    }
  else
    {
      return 1;
    }
}
开发者ID:texlive,项目名称:texlive-source,代码行数:13,代码来源:set_exp.c


示例18: mpfr_div_2si

int
mpfr_div_2si (mpfr_ptr y, mpfr_srcptr x, long int n, mp_rnd_t rnd_mode)
{
  int inexact;

  inexact = y != x ? mpfr_set (y, x, rnd_mode) : 0;

  if (MPFR_IS_FP(y) && MPFR_NOTZERO(y))
    {
      if (n > 0 && (__mpfr_emin > MPFR_EMAX_MAX - n ||
                    MPFR_EXP(y) < __mpfr_emin + n))
        return mpfr_set_underflow (y, rnd_mode, MPFR_SIGN(y));

      if (n < 0 && (__mpfr_emax < MPFR_EMIN_MIN - n ||
                    MPFR_EXP(y) > __mpfr_emax + n))
        return mpfr_set_overflow (y, rnd_mode, MPFR_SIGN(y));

      MPFR_EXP(y) -= n;
    }

  return inexact;
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:22,代码来源:div_2si.c


示例19: mpfr_check_range

int
mpfr_check_range (mpfr_ptr x, mp_rnd_t rnd_mode)
{
  if (MPFR_IS_FP(x) && MPFR_NOTZERO(x))
    { /* x is a non-zero FP */
      mp_exp_t exp = MPFR_EXP(x);
      if (exp < __mpfr_emin)
        return mpfr_set_underflow(x, rnd_mode, MPFR_SIGN(x));
      if (exp > __mpfr_emax)
        return mpfr_set_overflow(x, rnd_mode, MPFR_SIGN(x));
    }
  return 0;
}
开发者ID:mahdiz,项目名称:mpclib,代码行数:13,代码来源:exceptions.c


示例20: mpfr_fits_uintmax_p

/* We can't use fits_u.h <= mpfr_cmp_ui */
int
mpfr_fits_uintmax_p (mpfr_srcptr f, mp_rnd_t rnd)
{
  mp_exp_t exp;
  mp_prec_t prec;
  uintmax_t s;
  mpfr_t x, y;
  int res;

  if (MPFR_IS_NAN(f) || MPFR_IS_INF(f) || MPFR_SIGN(f) < 0)
    return 0; /* does not fit */

  if (MPFR_IS_ZERO(f))
    return 1; /* zero always fits */

  /* now it fits if
     (a) f <= MAXIMUM
     (b) round(f, prec(slong), rnd) <= MAXIMUM */

  exp = MPFR_EXP(f);
  if (exp < 1)
    return 1; /* |f| < 1: always fits */

  /* first compute prec(MAXIMUM) */
  for (s = UINTMAX_MAX, prec = 0; s != 0; s /= 2, prec ++);

  /* MAXIMUM needs prec bits, i.e. 2^(prec-1) <= |MAXIMUM| < 2^prec */

   /* if exp < prec - 1, then f < 2^(prec-1) < |MAXIMUM| */
  if ((mpfr_prec_t) exp < prec - 1)
    return 1;

  /* if exp > prec + 1, then f >= 2^prec > MAXIMUM */
  if ((mpfr_prec_t) exp > prec + 1)
    return 0;

  /* remains cases exp = prec-1 to prec+1 */

  /* hard case: first round to prec bits, then check */
  mpfr_init2 (x, prec);
  mpfr_init2 (y, prec);
  mpfr_set (x, f, rnd);
  res = mpfr_set_uj (y, UINTMAX_MAX, GMP_RNDN);
  MPFR_ASSERTD (res == 0);
  res = mpfr_cmp (x, y) <= 0;
  mpfr_clear (y);
  mpfr_clear (x);

  return res;
}
开发者ID:Scorpiion,项目名称:Renux_cross_gcc,代码行数:51,代码来源:fits_uintmax.c



注:本文中的MPFR_EXP函数示例由纯净天空整理自Github/MSDocs等源码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。


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C++ MPFR_GET_EXP函数代码示例发布时间:2022-05-30
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C++ MPFR_CAN_ROUND函数代码示例发布时间:2022-05-30
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