expm1l
long double expm1l(long double);
extern long double expm1l(long double);
t = expm1l(w);
extern long double expm1l(long double);
t = expm1l(r);
z = one - two / (expm1l(t + t) + two);
y = expm1l(-t - t);
t = w < tinyl ? w : expm1l(w);
extern long double expm1l(long double);
t = expm1l(r);
z = one - two / (expm1l(t + t) + two);
y = expm1l(-t - t);
t = expm1l(x + x);