Average Error: 25.4 → 8.6
Time: 9.2s
Precision: binary64
\[\]
↓
\[\]
↓
double code(double x, double y, double z, double t) {
	return ((double) (x - ((double) (((double) log(((double) (((double) (1.0 - y)) + ((double) (y * ((double) exp(z)))))))) / t))));
}

↓
double code(double x, double y, double z, double t) {
	double VAR;
	if ((z <= -1.2220751617360544e-37)) {
		VAR = ((double) (x - ((double) (((double) log(((double) (1.0 + ((double) (((double) (y * ((double) exp(z)))) - y)))))) * ((double) (1.0 / t))))));
	} else {
		VAR = ((double) (x - ((double) (((double) (((double) log(1.0)) + ((double) (y * ((double) (z * ((double) (1.0 + ((double) (z * 0.5)))))))))) / t))));
	}
	return VAR;
}

Error
Bits error versus x
Bits error versus y
Bits error versus z
Bits error versus t
Try it out
Your Program's Arguments
Results
Enter valid numbers for all inputs
Target
Original25.4
Target16.3
Herbie8.6
\[\]
Derivation
  1. Split input into 2 regimes
  2. if  z  < -1.22207516173605444e-37
    1. Initial program 13.2
      \[\]
    2. Simplified12.5
      \[\leadsto \]
    3. Using strategy rm
    4. Applied div-inv12.5
      \[\leadsto \]
    if -1.22207516173605444e-37 <  z 
    1. Initial program 31.5
      \[\]
    2. Simplified15.8
      \[\leadsto \]
    3. Taylor expanded around 0 6.7
      \[\leadsto \]
    4. Simplified6.7
      \[\leadsto \]
  3. Recombined 2 regimes into one program.
  4. Final simplification8.6
    \[\leadsto \]
Reproduce
herbie shell --seed 2020180 
(FPCore (x y z t)
  :name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
  :precision binary64

  :herbie-target
  (if (< z -2.8874623088207947e+119) (- (- x (/ (/ (neg 0.5) (* y t)) (* z z))) (* (/ (neg 0.5) (* y t)) (/ (/ 2.0 z) (* z z)))) (- x (/ (log (+ 1.0 (* z y))) t)))

  (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))