\frac{e^{x} - e^{-x}}{e^{x} + e^{-x}}\tanh x
double f(double x) {
double r52100 = x;
double r52101 = exp(r52100);
double r52102 = -r52100;
double r52103 = exp(r52102);
double r52104 = r52101 - r52103;
double r52105 = r52101 + r52103;
double r52106 = r52104 / r52105;
return r52106;
}
double f(double x) {
double r52107 = x;
double r52108 = tanh(r52107);
return r52108;
}



Bits error versus x
Results
Initial program 58.0
rmApplied tanh-undef0.0
Final simplification0.0
herbie shell --seed 2020100
(FPCore (x)
:name "Hyperbolic tangent"
:precision binary64
(/ (- (exp x) (exp (- x))) (+ (exp x) (exp (- x)))))