Average Error: 41.0 → 0.6
Time: 2.7s
Precision: binary64
\[\]
\[\]
double code(double x) {
	return ((double) (((double) exp(x)) / ((double) (((double) exp(x)) - 1.0))));
}
double code(double x) {
	double VAR;
	if ((x <= -0.0023147181705364885)) {
		VAR = ((double) (1.0 / ((double) (1.0 - ((double) exp(((double) (((double) log(1.0)) - x))))))));
	} else {
		VAR = ((double) (0.5 + ((double) (((double) (x * 0.08333333333333333)) + ((double) (1.0 / x))))));
	}
	return VAR;
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original41.0
Target40.6
Herbie0.6
\[\]

Derivation

  1. Split input into 2 regimes
  2. if x < -0.00231471817053648847

    1. Initial program 0.0

      \[\]
    2. Using strategy rm
    3. Applied clear-num0.0

      \[\leadsto \]
    4. Simplified0.0

      \[\leadsto \]
    5. Using strategy rm
    6. Applied add-exp-log0.0

      \[\leadsto \]
    7. Applied div-exp0.0

      \[\leadsto \]

    if -0.00231471817053648847 < x

    1. Initial program 62.0

      \[\]
    2. Taylor expanded around 0 0.9

      \[\leadsto \]
    3. Simplified0.9

      \[\leadsto \]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.6

    \[\leadsto \]

Reproduce

herbie shell --seed 2020181 
(FPCore (x)
  :name "expq2 (section 3.11)"
  :precision binary64

  :herbie-target
  (/ 1.0 (- 1.0 (exp (neg x))))

  (/ (exp x) (- (exp x) 1.0)))