#include "libm.h"

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long double tanhl(long double x) {
    return tanh(x);
}
#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
long double tanhl(long double x) {
    union ldshape u = {x};
    unsigned ex = u.i.se & 0x7fff;
    unsigned sign = u.i.se & 0x8000;
    uint32_t w;
    long double t;

    /* x = |x| */
    u.i.se = ex;
    x = u.f;
    w = u.i.m >> 32;

    if (ex > 0x3ffe || (ex == 0x3ffe && w > 0x8c9f53d5)) {
        /* |x| > log(3)/2 ~= 0.5493 or nan */
        if (ex >= 0x3fff + 5) {
            /* |x| >= 32 */
            t = 1 + 0 / (x + 0x1p-120f);
        } else {
            t = expm1l(2 * x);
            t = 1 - 2 / (t + 2);
        }
    } else if (ex > 0x3ffd || (ex == 0x3ffd && w > 0x82c577d4)) {
        /* |x| > log(5/3)/2 ~= 0.2554 */
        t = expm1l(2 * x);
        t = t / (t + 2);
    } else {
        /* |x| is small */
        t = expm1l(-2 * x);
        t = -t / (t + 2);
    }
    return sign ? -t : t;
}
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
// TODO: broken implementation to make things compile
long double tanhl(long double x) {
    return tanh(x);
}
#endif