src/math/coshl.c

   1 #include "libm.h"
   2
   3 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   4 long double coshl(long double x)
   5 {
   6         return cosh(x);
   7 }
   8 #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
   9 long double coshl(long double x)
  10 {
  11         union ldshape u = {x};
  12         unsigned ex = u.i.se & 0x7fff;
  13         uint32_t w;
  14         long double t;
  15
  16         /* |x| */
  17         u.i.se = ex;
  18         x = u.f;
  19         w = u.i.m >> 32;
  20
  21         /* |x| < log(2) */
  22         if (ex < 0x3fff-1 || (ex == 0x3fff-1 && w < 0xb17217f7)) {
  23                 if (ex < 0x3fff-32) {
  24                         FORCE_EVAL(x + 0x1p120f);
  25                         return 1;
  26                 }
  27                 t = expm1l(x);
  28                 return 1 + t*t/(2*(1+t));
  29         }
  30
  31         /* |x| < log(LDBL_MAX) */
  32         if (ex < 0x3fff+13 || (ex == 0x3fff+13 && w < 0xb17217f7)) {
  33                 t = expl(x);
  34                 return 0.5*(t + 1/t);
  35         }
  36
  37         /* |x| > log(LDBL_MAX) or nan */
  38         t = expl(0.5*x);
  39         return 0.5*t*t;
  40 }
  41 #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
  42 // TODO: broken implementation to make things compile
  43 long double coshl(long double x)
  44 {
  45         return cosh(x);
  46 }
  47 #endif