Average Error: 53.0 → 0.3
Time: 6.5s
Precision: binary64
\[\]
\[\]
double code(double x) {
	return ((double) log(((double) (x + ((double) sqrt(((double) (((double) (x * x)) + 1.0))))))));
}
double code(double x) {
	double VAR;
	if ((x <= -1.01671876785975)) {
		VAR = ((double) log(((double) (((double) (0.125 / ((double) pow(x, 3.0)))) - ((double) (((double) (0.5 / x)) + ((double) (0.0625 / ((double) pow(x, 5.0))))))))));
	} else {
		double VAR_1;
		if ((x <= 0.8860700991029492)) {
			VAR_1 = ((double) (((double) log(((double) sqrt(1.0)))) + ((double) (((double) (x / ((double) sqrt(1.0)))) + ((double) (((double) pow(((double) (x / ((double) sqrt(1.0)))), 3.0)) * -0.16666666666666666))))));
		} else {
			VAR_1 = ((double) log(((double) (((double) (x * 2.0)) + ((double) (((double) (0.5 / x)) - ((double) (0.125 / ((double) pow(x, 3.0))))))))));
		}
		VAR = VAR_1;
	}
	return VAR;
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original53.0
Target44.9
Herbie0.3
\[\]

Derivation

  1. Split input into 3 regimes
  2. if x < -1.01671876785975

    1. Initial program 63.3

      \[\]
    2. Taylor expanded around -inf 0.1

      \[\leadsto \]
    3. Simplified0.1

      \[\leadsto \]

    if -1.01671876785975 < x < 0.886070099102949205

    1. Initial program 58.7

      \[\]
    2. Taylor expanded around 0 0.3

      \[\leadsto \]
    3. Simplified0.3

      \[\leadsto \]

    if 0.886070099102949205 < x

    1. Initial program 31.1

      \[\]
    2. Taylor expanded around inf 0.3

      \[\leadsto \]
    3. Simplified0.3

      \[\leadsto \]
  3. Recombined 3 regimes into one program.
  4. Final simplification0.3

    \[\leadsto \]

Reproduce

herbie shell --seed 2020191 
(FPCore (x)
  :name "Hyperbolic arcsine"
  :precision binary64

  :herbie-target
  (if (< x 0.0) (log (/ -1.0 (- x (sqrt (+ (* x x) 1.0))))) (log (+ x (sqrt (+ (* x x) 1.0)))))

  (log (+ x (sqrt (+ (* x x) 1.0)))))