Average Error: 0.0 → 0.0
Time: 7.1s
Precision: 64
\[0 \le x \le 2\]
\[x \cdot \left(x \cdot x\right) + x \cdot x\]
↓
\[\mathsf{fma}\left(x \cdot x, x, x \cdot x\right)\]
x \cdot \left(x \cdot x\right) + x \cdot x
↓
\mathsf{fma}\left(x \cdot x, x, x \cdot x\right)
double f(double x) {
        double r2651500 = x;
        double r2651501 = r2651500 * r2651500;
        double r2651502 = r2651500 * r2651501;
        double r2651503 = r2651502 + r2651501;
        return r2651503;
}
↓
double f(double x) {
        double r2651504 = x;
        double r2651505 = r2651504 * r2651504;
        double r2651506 = fma(r2651505, r2651504, r2651505);
        return r2651506;
}

Error

Bits error versus x

Target

Original0.0
Target0.0
Herbie0.0
\[\left(\left(1.0 + x\right) \cdot x\right) \cdot x\]

Derivation

  1. Initial program 0.0

    \[x \cdot \left(x \cdot x\right) + x \cdot x\]

  2. Simplified0.0

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

  3. Final simplification0.0

    \[\leadsto \mathsf{fma}\left(x \cdot x, x, x \cdot x\right)\]

Reproduce

herbie shell --seed 2019154 +o rules:numerics
(FPCore (x)
  :name "Expression 3, p15"
  :pre (<= 0 x 2)

  :herbie-target
  (* (* (+ 1.0 x) x) x)

  (+ (* x (* x x)) (* x x)))