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

Average Error: 0.1 → 0.1

Time: 15.0s

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 r236697 = x;
        double r236698 = 0.5;
        double r236699 = r236697 * r236698;
        double r236700 = y;
        double r236701 = 1.0;
        double r236702 = z;
        double r236703 = r236701 - r236702;
        double r236704 = log(r236702);
        double r236705 = r236703 + r236704;
        double r236706 = r236700 * r236705;
        double r236707 = r236699 + r236706;
        return r236707;
}

↓

double f(double x, double y, double z) {
        double r236708 = x;
        double r236709 = 0.5;
        double r236710 = r236708 * r236709;
        double r236711 = y;
        double r236712 = 1.0;
        double r236713 = z;
        double r236714 = r236712 - r236713;
        double r236715 = log(r236713);
        double r236716 = r236714 + r236715;
        double r236717 = r236711 * r236716;
        double r236718 = r236710 + r236717;
        return r236718;
}

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 2019294 
(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)))))