src/math/tanl.c

   1 #include "libm.h"
   2
   3 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   4 long double tanl(long double x)
   5 {
   6         return tan(x);
   7 }
   8 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
   9 long double tanl(long double x)
  10 {
  11         union ldshape u = {x};
  12         long double y[2];
  13         unsigned n;
  14
  15         u.i.se &= 0x7fff;
  16         if (u.i.se == 0x7fff)
  17                 return x - x;
  18         if (u.f < M_PI_4) {
  19                 if (u.i.se < 0x3fff - LDBL_MANT_DIG/2) {
  20                         /* raise inexact if x!=0 and underflow if subnormal */
  21                         FORCE_EVAL(u.i.se == 0 ? x*0x1p-120f : x+0x1p120f);
  22                         return x;
  23                 }
  24                 return __tanl(x, 0, 0);
  25         }
  26         n = __rem_pio2l(x, y);
  27         return __tanl(y[0], y[1], n&1);
  28 }
  29 #endif