source: asp3_tinet_ecnl_arm/trunk/musl-1.1.18/src/math/asinhl.c@ 352

#include "libm.h"

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long double asinhl(long double x)
{
        return asinh(x);
}
#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
/* asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5) */
long double asinhl(long double x)
{
        union ldshape u = {x};
        unsigned e = u.i.se & 0x7fff;
        unsigned s = u.i.se >> 15;

        /* |x| */
        u.i.se = e;
        x = u.f;

        if (e >= 0x3fff + 32) {
                /* |x| >= 0x1p32 or inf or nan */
                x = logl(x) + 0.693147180559945309417232121458176568L;
        } else if (e >= 0x3fff + 1) {
                /* |x| >= 2 */
                x = logl(2*x + 1/(sqrtl(x*x+1)+x));
        } else if (e >= 0x3fff - 32) {
                /* |x| >= 0x1p-32 */
                x = log1pl(x + x*x/(sqrtl(x*x+1)+1));
        } else {
                /* |x| < 0x1p-32, raise inexact if x!=0 */
                FORCE_EVAL(x + 0x1p120f);
        }
        return s ? -x : x;
}
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
// TODO: broken implementation to make things compile
long double asinhl(long double x)
{
        return asinh(x);
}
#endif