System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2

Average Error: 0.1 → 0.1

Time: 16.8s

Precision: 64

Math

\[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)\]

↓

\[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)\]

C

double f(double x, double y, double z) {
        double r205034 = x;
        double r205035 = 0.5;
        double r205036 = r205034 * r205035;
        double r205037 = y;
        double r205038 = 1.0;
        double r205039 = z;
        double r205040 = r205038 - r205039;
        double r205041 = log(r205039);
        double r205042 = r205040 + r205041;
        double r205043 = r205037 * r205042;
        double r205044 = r205036 + r205043;
        return r205044;
}

↓

double f(double x, double y, double z) {
        double r205045 = x;
        double r205046 = 0.5;
        double r205047 = r205045 * r205046;
        double r205048 = y;
        double r205049 = 1.0;
        double r205050 = z;
        double r205051 = r205049 - r205050;
        double r205052 = log(r205050);
        double r205053 = r205051 + r205052;
        double r205054 = r205048 * r205053;
        double r205055 = r205047 + r205054;
        return r205055;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Target

Original	0.1
Target	0.1
Herbie	0.1

\[\left(y + 0.5 \cdot x\right) - y \cdot \left(z - \log z\right)\]

Derivation

1. Initial program 0.1

   \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)\]

2. Final simplification 0.1

   \[\leadsto x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)\]

Reproduce

herbie shell --seed 2019305 
(FPCore (x y z)
  :name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"
  :precision binary64

  :herbie-target
  (- (+ y (* 0.5 x)) (* y (- z (log z))))

  (+ (* x 0.5) (* y (+ (- 1 z) (log z)))))