Average Error: 2.3 → 0.4
Time: 7.5s
Precision: binary64
\[\left(\left(x + y \cdot z\right) + t \cdot a\right) + \left(a \cdot z\right) \cdot b\]
↓
\[\begin{array}{l} \mathbf{if}\;z \leq -6.779438934707718 \cdot 10^{-122} \lor \neg \left(z \leq 3.1649899919719994 \cdot 10^{-71}\right):\\ \;\;\;\;a \cdot t + \left(x + z \cdot \left(y + a \cdot b\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x + \left(z \cdot y + a \cdot \left(t + z \cdot b\right)\right)\\ \end{array}\]
\left(\left(x + y \cdot z\right) + t \cdot a\right) + \left(a \cdot z\right) \cdot b
↓
\begin{array}{l}
\mathbf{if}\;z \leq -6.779438934707718 \cdot 10^{-122} \lor \neg \left(z \leq 3.1649899919719994 \cdot 10^{-71}\right):\\
\;\;\;\;a \cdot t + \left(x + z \cdot \left(y + a \cdot b\right)\right)\\

\mathbf{else}:\\
\;\;\;\;x + \left(z \cdot y + a \cdot \left(t + z \cdot b\right)\right)\\

\end{array}
(FPCore (x y z t a b)
 :precision binary64
 (+ (+ (+ x (* y z)) (* t a)) (* (* a z) b)))
↓
(FPCore (x y z t a b)
 :precision binary64
 (if (or (<= z -6.779438934707718e-122) (not (<= z 3.1649899919719994e-71)))
   (+ (* a t) (+ x (* z (+ y (* a b)))))
   (+ x (+ (* z y) (* a (+ t (* z b)))))))
double code(double x, double y, double z, double t, double a, double b) {
	return ((x + (y * z)) + (t * a)) + ((a * z) * b);
}
↓
double code(double x, double y, double z, double t, double a, double b) {
	double tmp;
	if ((z <= -6.779438934707718e-122) || !(z <= 3.1649899919719994e-71)) {
		tmp = (a * t) + (x + (z * (y + (a * b))));
	} else {
		tmp = x + ((z * y) + (a * (t + (z * b))));
	}
	return tmp;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Bits error versus t

Bits error versus a

Bits error versus b

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original2.3
Target0.3
Herbie0.4
\[\begin{array}{l} \mathbf{if}\;z < -1.1820553527347888 \cdot 10^{+19}:\\ \;\;\;\;z \cdot \left(b \cdot a + y\right) + \left(x + t \cdot a\right)\\ \mathbf{elif}\;z < 4.7589743188364287 \cdot 10^{-122}:\\ \;\;\;\;\left(b \cdot z + t\right) \cdot a + \left(z \cdot y + x\right)\\ \mathbf{else}:\\ \;\;\;\;z \cdot \left(b \cdot a + y\right) + \left(x + t \cdot a\right)\\ \end{array}\]

Derivation

  1. Split input into 2 regimes

  2. if z < -6.7794389347077178e-122 or 3.16498999197199943e-71 < z

    1. Initial program 3.6

      \[\left(\left(x + y \cdot z\right) + t \cdot a\right) + \left(a \cdot z\right) \cdot b\]

    2. Taylor expanded around 0 5.2

      \[\leadsto \color{blue}{a \cdot \left(z \cdot b\right) + \left(x + \left(z \cdot y + t \cdot a\right)\right)}\]

    3. Simplified0.7

      \[\leadsto \color{blue}{a \cdot t + \left(x + z \cdot \left(y + a \cdot b\right)\right)}\]

    if -6.7794389347077178e-122 < z < 3.16498999197199943e-71

    1. Initial program 0.5

      \[\left(\left(x + y \cdot z\right) + t \cdot a\right) + \left(a \cdot z\right) \cdot b\]

    2. Simplified0.0

      \[\leadsto \color{blue}{x + \left(y \cdot z + a \cdot \left(t + z \cdot b\right)\right)}\]
  3. Recombined 2 regimes into one program.

  4. Final simplification0.4

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -6.779438934707718 \cdot 10^{-122} \lor \neg \left(z \leq 3.1649899919719994 \cdot 10^{-71}\right):\\ \;\;\;\;a \cdot t + \left(x + z \cdot \left(y + a \cdot b\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x + \left(z \cdot y + a \cdot \left(t + z \cdot b\right)\right)\\ \end{array}\]

Reproduce

herbie shell --seed 2021042 
(FPCore (x y z t a b)
  :name "Graphics.Rasterific.CubicBezier:cachedBezierAt from Rasterific-0.6.1"
  :precision binary64

  :herbie-target
  (if (< z -1.1820553527347888e+19) (+ (* z (+ (* b a) y)) (+ x (* t a))) (if (< z 4.7589743188364287e-122) (+ (* (+ (* b z) t) a) (+ (* z y) x)) (+ (* z (+ (* b a) y)) (+ x (* t a)))))

  (+ (+ (+ x (* y z)) (* t a)) (* (* a z) b)))