\frac{2}{e^{x} + e^{-x}}\frac{\sqrt{2}}{\sqrt{e^{x} + e^{-x}}} \cdot \frac{\sqrt{2}}{\sqrt{e^{x} + e^{-x}}}(FPCore (x) :precision binary64 (/ 2.0 (+ (exp x) (exp (- x)))))
(FPCore (x) :precision binary64 (* (/ (sqrt 2.0) (sqrt (+ (exp x) (exp (- x))))) (/ (sqrt 2.0) (sqrt (+ (exp x) (exp (- x)))))))
double code(double x) {
return 2.0 / (exp(x) + exp(-x));
}
double code(double x) {
return (sqrt(2.0) / sqrt(exp(x) + exp(-x))) * (sqrt(2.0) / sqrt(exp(x) + exp(-x)));
}



Bits error versus x
Results
Initial program 0.0
rmApplied add-sqr-sqrt_binary640.8
Applied add-sqr-sqrt_binary640.0
Applied times-frac_binary640.0
Final simplification0.0
herbie shell --seed 2021110
(FPCore (x)
:name "Hyperbolic secant"
:precision binary64
(/ 2.0 (+ (exp x) (exp (- x)))))