asinhl.c raw

   1  #include "libm.h"
   2  
   3  #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   4  long double asinhl(long double x)
   5  {
   6  	return asinh(x);
   7  }
   8  #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
   9  /* asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5) */
  10  long double asinhl(long double x)
  11  {
  12  	union ldshape u = {x};
  13  	unsigned e = u.i.se & 0x7fff;
  14  	unsigned s = u.i.se >> 15;
  15  
  16  	/* |x| */
  17  	u.i.se = e;
  18  	x = u.f;
  19  
  20  	if (e >= 0x3fff + 32) {
  21  		/* |x| >= 0x1p32 or inf or nan */
  22  		x = logl(x) + 0.693147180559945309417232121458176568L;
  23  	} else if (e >= 0x3fff + 1) {
  24  		/* |x| >= 2 */
  25  		x = logl(2*x + 1/(sqrtl(x*x+1)+x));
  26  	} else if (e >= 0x3fff - 32) {
  27  		/* |x| >= 0x1p-32 */
  28  		x = log1pl(x + x*x/(sqrtl(x*x+1)+1));
  29  	} else {
  30  		/* |x| < 0x1p-32, raise inexact if x!=0 */
  31  		FORCE_EVAL(x + 0x1p120f);
  32  	}
  33  	return s ? -x : x;
  34  }
  35  #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
  36  // TODO: broken implementation to make things compile
  37  long double asinhl(long double x)
  38  {
  39  	return asinh(x);
  40  }
  41  #endif
  42