Average Error: 6.0 → 0.1
Time: 15.6s
Precision: 64
\[x + \frac{y \cdot y}{z}\]
↓
\[\mathsf{fma}\left(\frac{y}{z}, y, x\right)\]
x + \frac{y \cdot y}{z}
↓
\mathsf{fma}\left(\frac{y}{z}, y, x\right)
double f(double x, double y, double z) {
        double r612654 = x;
        double r612655 = y;
        double r612656 = r612655 * r612655;
        double r612657 = z;
        double r612658 = r612656 / r612657;
        double r612659 = r612654 + r612658;
        return r612659;
}
↓
double f(double x, double y, double z) {
        double r612660 = y;
        double r612661 = z;
        double r612662 = r612660 / r612661;
        double r612663 = x;
        double r612664 = fma(r612662, r612660, r612663);
        return r612664;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Target

Original6.0
Target0.1
Herbie0.1
\[x + y \cdot \frac{y}{z}\]

Derivation

  1. Initial program 6.0

    \[x + \frac{y \cdot y}{z}\]

  2. Simplified0.1

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{y}{z}, y, x\right)}\]

  3. Final simplification0.1

    \[\leadsto \mathsf{fma}\left(\frac{y}{z}, y, x\right)\]

Reproduce

herbie shell --seed 2019304 +o rules:numerics
(FPCore (x y z)
  :name "Crypto.Random.Test:calculate from crypto-random-0.0.9"
  :precision binary64

  :herbie-target
  (+ x (* y (/ y z)))

  (+ x (/ (* y y) z)))