| Alternative 1 | |
|---|---|
| Accuracy | 99.8% |
| Cost | 6848 |
\[\mathsf{fma}\left(x, 6, x \cdot \left(x \cdot -9\right)\right)
\]

(FPCore (x) :precision binary64 (* (* 3.0 (- 2.0 (* x 3.0))) x))
(FPCore (x) :precision binary64 (fma x 6.0 (* x (* x -9.0))))
double code(double x) {
return (3.0 * (2.0 - (x * 3.0))) * x;
}
double code(double x) {
return fma(x, 6.0, (x * (x * -9.0)));
}
function code(x) return Float64(Float64(3.0 * Float64(2.0 - Float64(x * 3.0))) * x) end
function code(x) return fma(x, 6.0, Float64(x * Float64(x * -9.0))) end
code[x_] := N[(N[(3.0 * N[(2.0 - N[(x * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]
code[x_] := N[(x * 6.0 + N[(x * N[(x * -9.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\left(3 \cdot \left(2 - x \cdot 3\right)\right) \cdot x
\begin{array}{l}
\\
\mathsf{fma}\left(x, 6, x \cdot \left(x \cdot -9\right)\right)
\end{array}
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
| Original | 99.7% |
|---|---|
| Target | 99.7% |
| Herbie | 99.8% |
Initial program 99.7%
Simplified99.7%
[Start]99.7% | \[ \left(3 \cdot \left(2 - x \cdot 3\right)\right) \cdot x
\] |
|---|---|
*-commutative [=>]99.7% | \[ \color{blue}{x \cdot \left(3 \cdot \left(2 - x \cdot 3\right)\right)}
\] |
sub-neg [=>]99.7% | \[ x \cdot \left(3 \cdot \color{blue}{\left(2 + \left(-x \cdot 3\right)\right)}\right)
\] |
distribute-rgt-in [=>]99.7% | \[ x \cdot \color{blue}{\left(2 \cdot 3 + \left(-x \cdot 3\right) \cdot 3\right)}
\] |
metadata-eval [=>]99.7% | \[ x \cdot \left(\color{blue}{6} + \left(-x \cdot 3\right) \cdot 3\right)
\] |
distribute-rgt-neg-in [=>]99.7% | \[ x \cdot \left(6 + \color{blue}{\left(x \cdot \left(-3\right)\right)} \cdot 3\right)
\] |
associate-*l* [=>]99.7% | \[ x \cdot \left(6 + \color{blue}{x \cdot \left(\left(-3\right) \cdot 3\right)}\right)
\] |
metadata-eval [=>]99.7% | \[ x \cdot \left(6 + x \cdot \left(\color{blue}{-3} \cdot 3\right)\right)
\] |
metadata-eval [=>]99.7% | \[ x \cdot \left(6 + x \cdot \color{blue}{-9}\right)
\] |
Applied egg-rr99.8%
[Start]99.7% | \[ x \cdot \left(6 + x \cdot -9\right)
\] |
|---|---|
distribute-lft-in [=>]99.3% | \[ \color{blue}{x \cdot 6 + x \cdot \left(x \cdot -9\right)}
\] |
fma-def [=>]99.8% | \[ \color{blue}{\mathsf{fma}\left(x, 6, x \cdot \left(x \cdot -9\right)\right)}
\] |
Final simplification99.8%
| Alternative 1 | |
|---|---|
| Accuracy | 99.8% |
| Cost | 6848 |
| Alternative 2 | |
|---|---|
| Accuracy | 98.0% |
| Cost | 585 |
| Alternative 3 | |
|---|---|
| Accuracy | 99.8% |
| Cost | 448 |
| Alternative 4 | |
|---|---|
| Accuracy | 50.2% |
| Cost | 192 |
| Alternative 5 | |
|---|---|
| Accuracy | 2.3% |
| Cost | 64 |
herbie shell --seed 2023167
(FPCore (x)
:name "Diagrams.Tangent:$catParam from diagrams-lib-1.3.0.3, E"
:precision binary64
:herbie-target
(- (* 6.0 x) (* 9.0 (* x x)))
(* (* 3.0 (- 2.0 (* x 3.0))) x))