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