src/math/asinhl.c

   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