C++ (Cpp) M_LOG1P Examples

Example #1

File: s_catanh_template.c Project: riscv/riscv-glibc

CFLOAT
M_DECL_FUNC (__catanh) (CFLOAT x)
{
  CFLOAT res;
  int rcls = fpclassify (__real__ x);
  int icls = fpclassify (__imag__ x);

  if (__glibc_unlikely (rcls <= FP_INFINITE || icls <= FP_INFINITE))
    {
      if (icls == FP_INFINITE)
	{
	  __real__ res = M_COPYSIGN (0, __real__ x);
	  __imag__ res = M_COPYSIGN (M_MLIT (M_PI_2), __imag__ x);
	}
      else if (rcls == FP_INFINITE || rcls == FP_ZERO)
	{
	  __real__ res = M_COPYSIGN (0, __real__ x);
	  if (icls >= FP_ZERO)
	    __imag__ res = M_COPYSIGN (M_MLIT (M_PI_2), __imag__ x);
	  else
	    __imag__ res = M_NAN;
	}
      else
	{
	  __real__ res = M_NAN;
	  __imag__ res = M_NAN;
	}
    }
  else if (__glibc_unlikely (rcls == FP_ZERO && icls == FP_ZERO))
    {
      res = x;
    }
  else
    {
      if (M_FABS (__real__ x) >= 16 / M_EPSILON
	  || M_FABS (__imag__ x) >= 16 / M_EPSILON)
	{
	  __imag__ res = M_COPYSIGN (M_MLIT (M_PI_2), __imag__ x);
	  if (M_FABS (__imag__ x) <= 1)
	    __real__ res = 1 / __real__ x;
	  else if (M_FABS (__real__ x) <= 1)
	    __real__ res = __real__ x / __imag__ x / __imag__ x;
	  else
	    {
	      FLOAT h = M_HYPOT (__real__ x / 2, __imag__ x / 2);
	      __real__ res = __real__ x / h / h / 4;
	    }
	}
      else
	{
	  if (M_FABS (__real__ x) == 1
	      && M_FABS (__imag__ x) < M_EPSILON * M_EPSILON)
	    __real__ res = (M_COPYSIGN (M_LIT (0.5), __real__ x)
			    * ((FLOAT) M_MLIT (M_LN2)
			       - M_LOG (M_FABS (__imag__ x))));
	  else
	    {
	      FLOAT i2 = 0;
	      if (M_FABS (__imag__ x) >= M_EPSILON * M_EPSILON)
		i2 = __imag__ x * __imag__ x;

	      FLOAT num = 1 + __real__ x;
	      num = i2 + num * num;

	      FLOAT den = 1 - __real__ x;
	      den = i2 + den * den;

	      FLOAT f = num / den;
	      if (f < M_LIT (0.5))
		__real__ res = M_LIT (0.25) * M_LOG (f);
	      else
		{
		  num = 4 * __real__ x;
		  __real__ res = M_LIT (0.25) * M_LOG1P (num / den);
		}
	    }

	  FLOAT absx, absy, den;

	  absx = M_FABS (__real__ x);
	  absy = M_FABS (__imag__ x);
	  if (absx < absy)
	    {
	      FLOAT t = absx;
	      absx = absy;
	      absy = t;
	    }

	  if (absy < M_EPSILON / 2)
	    {
	      den = (1 - absx) * (1 + absx);
	      if (den == 0)
		den = 0;
	    }
	  else if (absx >= 1)
	    den = (1 - absx) * (1 + absx) - absy * absy;
	  else if (absx >= M_LIT (0.75) || absy >= M_LIT (0.5))
	    den = -M_SUF (__x2y2m1) (absx, absy);
	  else
	    den = (1 - absx) * (1 + absx) - absy * absy;

	  __imag__ res = M_LIT (0.5) * M_ATAN2 (2 * __imag__ x, den);
	}

      math_check_force_underflow_complex (res);
    }

  return res;
}

Example #2

File: s_clog_template.c Project: siddhesh/glibc

CFLOAT
M_DECL_FUNC (__clog) (CFLOAT x)
{
  CFLOAT result;
  int rcls = fpclassify (__real__ x);
  int icls = fpclassify (__imag__ x);

  if (__glibc_unlikely (rcls == FP_ZERO && icls == FP_ZERO))
    {
      /* Real and imaginary part are 0.0.  */
      __imag__ result = signbit (__real__ x) ? (FLOAT) M_MLIT (M_PI) : 0;
      __imag__ result = M_COPYSIGN (__imag__ result, __imag__ x);
      /* Yes, the following line raises an exception.  */
      __real__ result = -1 / M_FABS (__real__ x);
    }
  else if (__glibc_likely (rcls != FP_NAN && icls != FP_NAN))
    {
      /* Neither real nor imaginary part is NaN.  */
      FLOAT absx = M_FABS (__real__ x), absy = M_FABS (__imag__ x);
      int scale = 0;

      if (absx < absy)
	{
	  FLOAT t = absx;
	  absx = absy;
	  absy = t;
	}

      if (absx > M_MAX / 2)
	{
	  scale = -1;
	  absx = M_SCALBN (absx, scale);
	  absy = (absy >= M_MIN * 2 ? M_SCALBN (absy, scale) : 0);
	}
      else if (absx < M_MIN && absy < M_MIN)
	{
	  scale = M_MANT_DIG;
	  absx = M_SCALBN (absx, scale);
	  absy = M_SCALBN (absy, scale);
	}

      if (absx == 1 && scale == 0)
	{
	  __real__ result = M_LOG1P (absy * absy) / 2;
	  math_check_force_underflow_nonneg (__real__ result);
	}
      else if (absx > 1 && absx < 2 && absy < 1 && scale == 0)
	{
	  FLOAT d2m1 = (absx - 1) * (absx + 1);
	  if (absy >= M_EPSILON)
	    d2m1 += absy * absy;
	  __real__ result = M_LOG1P (d2m1) / 2;
	}
      else if (absx < 1
	       && absx >= M_LIT (0.5)
	       && absy < M_EPSILON / 2
	       && scale == 0)
	{
	  FLOAT d2m1 = (absx - 1) * (absx + 1);
	  __real__ result = M_LOG1P (d2m1) / 2;
	}
      else if (absx < 1
	       && absx >= M_LIT (0.5)
	       && scale == 0
	       && absx * absx + absy * absy >= M_LIT (0.5))
	{
	  FLOAT d2m1 = M_SUF (__x2y2m1) (absx, absy);
	  __real__ result = M_LOG1P (d2m1) / 2;
	}
      else
	{
	  FLOAT d = M_HYPOT (absx, absy);
	  __real__ result = M_LOG (d) - scale * (FLOAT) M_MLIT (M_LN2);
	}

      __imag__ result = M_ATAN2 (__imag__ x, __real__ x);
    }
  else
    {
      __imag__ result = M_NAN;
      if (rcls == FP_INFINITE || icls == FP_INFINITE)
	/* Real or imaginary part is infinite.  */
	__real__ result = M_HUGE_VAL;
      else
	__real__ result = M_NAN;
    }

  return result;
}