Average Error: 9.1 → 0.1
Time: 4.5s
Precision: binary64
\[\frac{x}{y} + \frac{2 + \left(z \cdot 2\right) \cdot \left(1 - t\right)}{t \cdot z}\]
↓
\[\frac{x}{y} + \left(2 \cdot \frac{\frac{1}{z} + 1}{t} - 2\right)\]
\frac{x}{y} + \frac{2 + \left(z \cdot 2\right) \cdot \left(1 - t\right)}{t \cdot z}
↓
\frac{x}{y} + \left(2 \cdot \frac{\frac{1}{z} + 1}{t} - 2\right)
(FPCore (x y z t)
 :precision binary64
 (+ (/ x y) (/ (+ 2.0 (* (* z 2.0) (- 1.0 t))) (* t z))))
↓
(FPCore (x y z t)
 :precision binary64
 (+ (/ x y) (- (* 2.0 (/ (+ (/ 1.0 z) 1.0) t)) 2.0)))
double code(double x, double y, double z, double t) {
	return ((double) ((x / y) + (((double) (2.0 + ((double) (((double) (z * 2.0)) * ((double) (1.0 - t)))))) / ((double) (t * z)))));
}
↓
double code(double x, double y, double z, double t) {
	return ((double) ((x / y) + ((double) (((double) (2.0 * (((double) ((1.0 / z) + 1.0)) / t))) - 2.0))));
}

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

Original9.1
Target0.1
Herbie0.1
\[\frac{\frac{2}{z} + 2}{t} - \left(2 - \frac{x}{y}\right)\]

Derivation

  1. Initial program Error: 9.1 bits

    \[\frac{x}{y} + \frac{2 + \left(z \cdot 2\right) \cdot \left(1 - t\right)}{t \cdot z}\]

  2. SimplifiedError: 0.1 bits

    \[\leadsto \color{blue}{\frac{x}{y} + \left(\frac{2}{t} \cdot \left(\frac{1}{z} + 1\right) - 2\right)}\]
  3. Using strategy rm

  4. Applied div-invError: 0.1 bits

    \[\leadsto \frac{x}{y} + \left(\color{blue}{\left(2 \cdot \frac{1}{t}\right)} \cdot \left(\frac{1}{z} + 1\right) - 2\right)\]

  5. Applied associate-*l*Error: 0.1 bits

    \[\leadsto \frac{x}{y} + \left(\color{blue}{2 \cdot \left(\frac{1}{t} \cdot \left(\frac{1}{z} + 1\right)\right)} - 2\right)\]

  6. SimplifiedError: 0.1 bits

    \[\leadsto \frac{x}{y} + \left(2 \cdot \color{blue}{\frac{\frac{1}{z} + 1}{t}} - 2\right)\]

  7. Final simplificationError: 0.1 bits

    \[\leadsto \frac{x}{y} + \left(2 \cdot \frac{\frac{1}{z} + 1}{t} - 2\right)\]

Reproduce

herbie shell --seed 2020204 
(FPCore (x y z t)
  :name "Data.HashTable.ST.Basic:computeOverhead from hashtables-1.2.0.2"
  :precision binary64

  :herbie-target
  (- (/ (+ (/ 2.0 z) 2.0) t) (- 2.0 (/ x y)))

  (+ (/ x y) (/ (+ 2.0 (* (* z 2.0) (- 1.0 t))) (* t z))))