src/math/cosl.c

   1 #include "libm.h"
   2
   3 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   4 long double cosl(long double x) {
   5         return cos(x);
   6 }
   7 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
   8 long double cosl(long double x)
   9 {
  10         union ldshape u = {x};
  11         unsigned n;
  12         long double y[2], hi, lo;
  13
  14         u.i.se &= 0x7fff;
  15         if (u.i.se == 0x7fff)
  16                 return x - x;
  17         x = u.f;
  18         if (x < M_PI_4) {
  19                 if (u.i.se < 0x3fff - LDBL_MANT_DIG)
  20                         /* raise inexact if x!=0 */
  21                         return 1.0 + x;
  22                 return __cosl(x, 0);
  23         }
  24         n = __rem_pio2l(x, y);
  25         hi = y[0];
  26         lo = y[1];
  27         switch (n & 3) {
  28         case 0:
  29                 return __cosl(hi, lo);
  30         case 1:
  31                 return -__sinl(hi, lo, 1);
  32         case 2:
  33                 return -__cosl(hi, lo);
  34         case 3:
  35         default:
  36                 return __sinl(hi, lo, 1);
  37         }
  38 }
  39 #endif