1#include "libm.h"
2
3#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
4long double tanhl(long double x)
5{
6 return tanh(x);
7}
8#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
9long double tanhl(long double x)
10{
11 union ldshape u = {x};
12 unsigned ex = u.i.se & 0x7fff;
13 unsigned sign = u.i.se & 0x8000;
14 uint32_t w;
15 long double t;
16
17 /* x = |x| */
18 u.i.se = ex;
19 x = u.f;
20 w = u.i.m >> 32;
21
22 if (ex > 0x3ffe || (ex == 0x3ffe && w > 0x8c9f53d5)) {
23 /* |x| > log(3)/2 ~= 0.5493 or nan */
24 if (ex >= 0x3fff+5) {
25 /* |x| >= 32 */
26 t = 1 + 0/(x + 0x1p-120f);
27 } else {
28 t = expm1l(2*x);
29 t = 1 - 2/(t+2);
30 }
31 } else if (ex > 0x3ffd || (ex == 0x3ffd && w > 0x82c577d4)) {
32 /* |x| > log(5/3)/2 ~= 0.2554 */
33 t = expm1l(2*x);
34 t = t/(t+2);
35 } else {
36 /* |x| is small */
37 t = expm1l(-2*x);
38 t = -t/(t+2);
39 }
40 return sign ? -t : t;
41}
42#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
43// TODO: broken implementation to make things compile
44long double tanhl(long double x)
45{
46 return tanh(x);
47}
48#endif