Expression 2, p15

Average Error: 0.0 → 0

Time: 5.5s

Precision: 64

• Falling back on racket egraph because egg-herbie package not installed

\[0.0 \le x \le 2\]

Math

\[x + x \cdot x\]

↓

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

C

double f(double x) {
        double r98681 = x;
        double r98682 = r98681 * r98681;
        double r98683 = r98681 + r98682;
        return r98683;
}

↓

double f(double x) {
        double r98684 = x;
        double r98685 = fma(r98684, r98684, r98684);
        return r98685;
}

Error

Bits error versus x

Target

Original	0.0
Target	0.0
Herbie	0

\[\left(1 + x\right) \cdot x\]

Derivation

1. Initial program 0.0

   \[x + x \cdot x\]

2. Simplified 0

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

3. Final simplification 0

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

Reproduce

herbie shell --seed 2020047 +o rules:numerics
(FPCore (x)
  :name "Expression 2, p15"
  :precision binary64
  :pre (<= 0.0 x 2)

  :herbie-target
  (* (+ 1 x) x)

  (+ x (* x x)))