2cbrt (problem 3.3.4)

Percentage Accurate: 6.9% → 96.8%
Time: 20.1s
Alternatives: 7
Speedup: 1.0×

Specification

?
\[x > 1 \land x < 10^{+308}\]
\[\begin{array}{l} \\ \sqrt[3]{x + 1} - \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (- (cbrt (+ x 1.0)) (cbrt x)))
double code(double x) {
	return cbrt((x + 1.0)) - cbrt(x);
}
public static double code(double x) {
	return Math.cbrt((x + 1.0)) - Math.cbrt(x);
}
function code(x)
	return Float64(cbrt(Float64(x + 1.0)) - cbrt(x))
end
code[x_] := N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{x + 1} - \sqrt[3]{x}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 7 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 6.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt[3]{x + 1} - \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (- (cbrt (+ x 1.0)) (cbrt x)))
double code(double x) {
	return cbrt((x + 1.0)) - cbrt(x);
}
public static double code(double x) {
	return Math.cbrt((x + 1.0)) - Math.cbrt(x);
}
function code(x)
	return Float64(cbrt(Float64(x + 1.0)) - cbrt(x))
end
code[x_] := N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{x + 1} - \sqrt[3]{x}
\end{array}

Alternative 1: 96.8% accurate, 0.3× speedup?

\[\begin{array}{l} \\ {\left(\frac{x \cdot \left(-0.05555555555555555 \cdot \left(\sqrt[3]{\frac{1}{{x}^{4}}} \cdot \frac{1}{\sqrt{0.3333333333333333}}\right) + \sqrt{0.3333333333333333} \cdot \sqrt[3]{\frac{1}{x}}\right)}{x}\right)}^{2} \end{array} \]
(FPCore (x)
 :precision binary64
 (pow
  (/
   (*
    x
    (+
     (*
      -0.05555555555555555
      (* (cbrt (/ 1.0 (pow x 4.0))) (/ 1.0 (sqrt 0.3333333333333333))))
     (* (sqrt 0.3333333333333333) (cbrt (/ 1.0 x)))))
   x)
  2.0))
double code(double x) {
	return pow(((x * ((-0.05555555555555555 * (cbrt((1.0 / pow(x, 4.0))) * (1.0 / sqrt(0.3333333333333333)))) + (sqrt(0.3333333333333333) * cbrt((1.0 / x))))) / x), 2.0);
}
public static double code(double x) {
	return Math.pow(((x * ((-0.05555555555555555 * (Math.cbrt((1.0 / Math.pow(x, 4.0))) * (1.0 / Math.sqrt(0.3333333333333333)))) + (Math.sqrt(0.3333333333333333) * Math.cbrt((1.0 / x))))) / x), 2.0);
}
function code(x)
	return Float64(Float64(x * Float64(Float64(-0.05555555555555555 * Float64(cbrt(Float64(1.0 / (x ^ 4.0))) * Float64(1.0 / sqrt(0.3333333333333333)))) + Float64(sqrt(0.3333333333333333) * cbrt(Float64(1.0 / x))))) / x) ^ 2.0
end
code[x_] := N[Power[N[(N[(x * N[(N[(-0.05555555555555555 * N[(N[Power[N[(1.0 / N[Power[x, 4.0], $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision] * N[(1.0 / N[Sqrt[0.3333333333333333], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[0.3333333333333333], $MachinePrecision] * N[Power[N[(1.0 / x), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], 2.0], $MachinePrecision]
\begin{array}{l}

\\
{\left(\frac{x \cdot \left(-0.05555555555555555 \cdot \left(\sqrt[3]{\frac{1}{{x}^{4}}} \cdot \frac{1}{\sqrt{0.3333333333333333}}\right) + \sqrt{0.3333333333333333} \cdot \sqrt[3]{\frac{1}{x}}\right)}{x}\right)}^{2}
\end{array}
Derivation
  1. Initial program 5.3%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 26.5%

    \[\leadsto \color{blue}{\frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \sqrt[3]{{x}^{4}}}{{x}^{2}}} \]
  4. Step-by-step derivation
    1. add-sqr-sqrt26.4%

      \[\leadsto \color{blue}{\sqrt{\frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \sqrt[3]{{x}^{4}}}{{x}^{2}}} \cdot \sqrt{\frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \sqrt[3]{{x}^{4}}}{{x}^{2}}}} \]
    2. pow226.4%

      \[\leadsto \color{blue}{{\left(\sqrt{\frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \sqrt[3]{{x}^{4}}}{{x}^{2}}}\right)}^{2}} \]
    3. sqrt-div26.4%

      \[\leadsto {\color{blue}{\left(\frac{\sqrt{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \sqrt[3]{{x}^{4}}}}{\sqrt{{x}^{2}}}\right)}}^{2} \]
    4. +-commutative26.4%

      \[\leadsto {\left(\frac{\sqrt{\color{blue}{0.3333333333333333 \cdot \sqrt[3]{{x}^{4}} + -0.1111111111111111 \cdot \sqrt[3]{x}}}}{\sqrt{{x}^{2}}}\right)}^{2} \]
    5. fma-define26.4%

      \[\leadsto {\left(\frac{\sqrt{\color{blue}{\mathsf{fma}\left(0.3333333333333333, \sqrt[3]{{x}^{4}}, -0.1111111111111111 \cdot \sqrt[3]{x}\right)}}}{\sqrt{{x}^{2}}}\right)}^{2} \]
    6. *-commutative26.4%

      \[\leadsto {\left(\frac{\sqrt{\mathsf{fma}\left(0.3333333333333333, \sqrt[3]{{x}^{4}}, \color{blue}{\sqrt[3]{x} \cdot -0.1111111111111111}\right)}}{\sqrt{{x}^{2}}}\right)}^{2} \]
    7. sqrt-pow127.5%

      \[\leadsto {\left(\frac{\sqrt{\mathsf{fma}\left(0.3333333333333333, \sqrt[3]{{x}^{4}}, \sqrt[3]{x} \cdot -0.1111111111111111\right)}}{\color{blue}{{x}^{\left(\frac{2}{2}\right)}}}\right)}^{2} \]
    8. metadata-eval27.5%

      \[\leadsto {\left(\frac{\sqrt{\mathsf{fma}\left(0.3333333333333333, \sqrt[3]{{x}^{4}}, \sqrt[3]{x} \cdot -0.1111111111111111\right)}}{{x}^{\color{blue}{1}}}\right)}^{2} \]
    9. pow127.5%

      \[\leadsto {\left(\frac{\sqrt{\mathsf{fma}\left(0.3333333333333333, \sqrt[3]{{x}^{4}}, \sqrt[3]{x} \cdot -0.1111111111111111\right)}}{\color{blue}{x}}\right)}^{2} \]
  5. Applied egg-rr27.5%

    \[\leadsto \color{blue}{{\left(\frac{\sqrt{\mathsf{fma}\left(0.3333333333333333, \sqrt[3]{{x}^{4}}, \sqrt[3]{x} \cdot -0.1111111111111111\right)}}{x}\right)}^{2}} \]
  6. Taylor expanded in x around inf 97.7%

    \[\leadsto {\left(\frac{\color{blue}{x \cdot \left(-0.05555555555555555 \cdot \left(\sqrt[3]{\frac{1}{{x}^{4}}} \cdot \frac{1}{\sqrt{0.3333333333333333}}\right) + \sqrt[3]{\frac{1}{x}} \cdot \sqrt{0.3333333333333333}\right)}}{x}\right)}^{2} \]
  7. Final simplification97.7%

    \[\leadsto {\left(\frac{x \cdot \left(-0.05555555555555555 \cdot \left(\sqrt[3]{\frac{1}{{x}^{4}}} \cdot \frac{1}{\sqrt{0.3333333333333333}}\right) + \sqrt{0.3333333333333333} \cdot \sqrt[3]{\frac{1}{x}}\right)}{x}\right)}^{2} \]
  8. Add Preprocessing

Alternative 2: 95.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.55 \cdot 10^{+231}:\\ \;\;\;\;\frac{1}{x} \cdot \frac{\mathsf{fma}\left(0.3333333333333333, {\left(\sqrt[3]{x}\right)}^{4}, \sqrt[3]{x \cdot -0.0013717421124828531}\right)}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, e^{\mathsf{log1p}\left(x\right) \cdot 0.6666666666666666}\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.55e+231)
   (*
    (/ 1.0 x)
    (/
     (fma
      0.3333333333333333
      (pow (cbrt x) 4.0)
      (cbrt (* x -0.0013717421124828531)))
     x))
   (/
    1.0
    (fma
     (cbrt x)
     (+ (cbrt x) (cbrt (+ x 1.0)))
     (exp (* (log1p x) 0.6666666666666666))))))
double code(double x) {
	double tmp;
	if (x <= 1.55e+231) {
		tmp = (1.0 / x) * (fma(0.3333333333333333, pow(cbrt(x), 4.0), cbrt((x * -0.0013717421124828531))) / x);
	} else {
		tmp = 1.0 / fma(cbrt(x), (cbrt(x) + cbrt((x + 1.0))), exp((log1p(x) * 0.6666666666666666)));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.55e+231)
		tmp = Float64(Float64(1.0 / x) * Float64(fma(0.3333333333333333, (cbrt(x) ^ 4.0), cbrt(Float64(x * -0.0013717421124828531))) / x));
	else
		tmp = Float64(1.0 / fma(cbrt(x), Float64(cbrt(x) + cbrt(Float64(x + 1.0))), exp(Float64(log1p(x) * 0.6666666666666666))));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.55e+231], N[(N[(1.0 / x), $MachinePrecision] * N[(N[(0.3333333333333333 * N[Power[N[Power[x, 1/3], $MachinePrecision], 4.0], $MachinePrecision] + N[Power[N[(x * -0.0013717421124828531), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Power[x, 1/3], $MachinePrecision] * N[(N[Power[x, 1/3], $MachinePrecision] + N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] + N[Exp[N[(N[Log[1 + x], $MachinePrecision] * 0.6666666666666666), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.55 \cdot 10^{+231}:\\
\;\;\;\;\frac{1}{x} \cdot \frac{\mathsf{fma}\left(0.3333333333333333, {\left(\sqrt[3]{x}\right)}^{4}, \sqrt[3]{x \cdot -0.0013717421124828531}\right)}{x}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, e^{\mathsf{log1p}\left(x\right) \cdot 0.6666666666666666}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.54999999999999995e231

    1. Initial program 5.4%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 33.1%

      \[\leadsto \color{blue}{\frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \sqrt[3]{{x}^{4}}}{{x}^{2}}} \]
    4. Step-by-step derivation
      1. pow1/330.7%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{\left({x}^{4}\right)}^{0.3333333333333333}}}{{x}^{2}} \]
      2. pow-pow62.5%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{x}^{\left(4 \cdot 0.3333333333333333\right)}}}{{x}^{2}} \]
      3. metadata-eval62.5%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot {x}^{\color{blue}{1.3333333333333333}}}{{x}^{2}} \]
    5. Applied egg-rr62.5%

      \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{x}^{1.3333333333333333}}}{{x}^{2}} \]
    6. Applied egg-rr97.5%

      \[\leadsto \color{blue}{\frac{1}{x} \cdot \frac{\mathsf{fma}\left(0.3333333333333333, {\left(\sqrt[3]{x}\right)}^{4}, \sqrt[3]{x \cdot -0.0013717421124828531}\right)}{x}} \]

    if 1.54999999999999995e231 < x

    1. Initial program 5.1%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip3--5.1%

        \[\leadsto \color{blue}{\frac{{\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
      2. div-inv5.1%

        \[\leadsto \color{blue}{\left({\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
      3. rem-cube-cbrt3.0%

        \[\leadsto \left(\color{blue}{\left(x + 1\right)} - {\left(\sqrt[3]{x}\right)}^{3}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      4. rem-cube-cbrt5.1%

        \[\leadsto \left(\left(x + 1\right) - \color{blue}{x}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      5. +-commutative5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right) + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}}} \]
      6. distribute-rgt-out5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x + 1}\right)} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}} \]
      7. +-commutative5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\sqrt[3]{x} \cdot \color{blue}{\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right)} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}} \]
      8. fma-define5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right)}} \]
      9. add-exp-log5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, \color{blue}{e^{\log \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right)}}\right)} \]
    4. Applied egg-rr5.1%

      \[\leadsto \color{blue}{\left(\left(x + 1\right) - x\right) \cdot \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)}} \]
    5. Step-by-step derivation
      1. associate-*r/5.1%

        \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot 1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)}} \]
      2. *-rgt-identity5.1%

        \[\leadsto \frac{\color{blue}{\left(x + 1\right) - x}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      3. +-commutative5.1%

        \[\leadsto \frac{\color{blue}{\left(1 + x\right)} - x}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      4. associate--l+91.3%

        \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      5. +-inverses91.3%

        \[\leadsto \frac{1 + \color{blue}{0}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      6. metadata-eval91.3%

        \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      7. +-commutative91.3%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{\color{blue}{1 + x}} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      8. exp-prod90.5%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, \color{blue}{{\left(e^{0.6666666666666666}\right)}^{\left(\mathsf{log1p}\left(x\right)\right)}}\right)} \]
    6. Simplified90.5%

      \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, {\left(e^{0.6666666666666666}\right)}^{\left(\mathsf{log1p}\left(x\right)\right)}\right)}} \]
    7. Step-by-step derivation
      1. add-exp-log90.8%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, \color{blue}{e^{\log \left({\left(e^{0.6666666666666666}\right)}^{\left(\mathsf{log1p}\left(x\right)\right)}\right)}}\right)} \]
      2. log-pow91.3%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, e^{\color{blue}{\mathsf{log1p}\left(x\right) \cdot \log \left(e^{0.6666666666666666}\right)}}\right)} \]
      3. rem-log-exp91.3%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, e^{\mathsf{log1p}\left(x\right) \cdot \color{blue}{0.6666666666666666}}\right)} \]
    8. Applied egg-rr91.3%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, \color{blue}{e^{\mathsf{log1p}\left(x\right) \cdot 0.6666666666666666}}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification96.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.55 \cdot 10^{+231}:\\ \;\;\;\;\frac{1}{x} \cdot \frac{\mathsf{fma}\left(0.3333333333333333, {\left(\sqrt[3]{x}\right)}^{4}, \sqrt[3]{x \cdot -0.0013717421124828531}\right)}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, e^{\mathsf{log1p}\left(x\right) \cdot 0.6666666666666666}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 77.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.55 \cdot 10^{+231}:\\ \;\;\;\;\frac{1}{x} \cdot \frac{\mathsf{fma}\left(0.3333333333333333, {\left(\sqrt[3]{x}\right)}^{4}, \sqrt[3]{x \cdot -0.0013717421124828531}\right)}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, 1\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.55e+231)
   (*
    (/ 1.0 x)
    (/
     (fma
      0.3333333333333333
      (pow (cbrt x) 4.0)
      (cbrt (* x -0.0013717421124828531)))
     x))
   (/ 1.0 (fma (cbrt x) (+ (cbrt x) (cbrt (+ x 1.0))) 1.0))))
double code(double x) {
	double tmp;
	if (x <= 1.55e+231) {
		tmp = (1.0 / x) * (fma(0.3333333333333333, pow(cbrt(x), 4.0), cbrt((x * -0.0013717421124828531))) / x);
	} else {
		tmp = 1.0 / fma(cbrt(x), (cbrt(x) + cbrt((x + 1.0))), 1.0);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.55e+231)
		tmp = Float64(Float64(1.0 / x) * Float64(fma(0.3333333333333333, (cbrt(x) ^ 4.0), cbrt(Float64(x * -0.0013717421124828531))) / x));
	else
		tmp = Float64(1.0 / fma(cbrt(x), Float64(cbrt(x) + cbrt(Float64(x + 1.0))), 1.0));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.55e+231], N[(N[(1.0 / x), $MachinePrecision] * N[(N[(0.3333333333333333 * N[Power[N[Power[x, 1/3], $MachinePrecision], 4.0], $MachinePrecision] + N[Power[N[(x * -0.0013717421124828531), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Power[x, 1/3], $MachinePrecision] * N[(N[Power[x, 1/3], $MachinePrecision] + N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.55 \cdot 10^{+231}:\\
\;\;\;\;\frac{1}{x} \cdot \frac{\mathsf{fma}\left(0.3333333333333333, {\left(\sqrt[3]{x}\right)}^{4}, \sqrt[3]{x \cdot -0.0013717421124828531}\right)}{x}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, 1\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.54999999999999995e231

    1. Initial program 5.4%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 33.1%

      \[\leadsto \color{blue}{\frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \sqrt[3]{{x}^{4}}}{{x}^{2}}} \]
    4. Step-by-step derivation
      1. pow1/330.7%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{\left({x}^{4}\right)}^{0.3333333333333333}}}{{x}^{2}} \]
      2. pow-pow62.5%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{x}^{\left(4 \cdot 0.3333333333333333\right)}}}{{x}^{2}} \]
      3. metadata-eval62.5%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot {x}^{\color{blue}{1.3333333333333333}}}{{x}^{2}} \]
    5. Applied egg-rr62.5%

      \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{x}^{1.3333333333333333}}}{{x}^{2}} \]
    6. Applied egg-rr97.5%

      \[\leadsto \color{blue}{\frac{1}{x} \cdot \frac{\mathsf{fma}\left(0.3333333333333333, {\left(\sqrt[3]{x}\right)}^{4}, \sqrt[3]{x \cdot -0.0013717421124828531}\right)}{x}} \]

    if 1.54999999999999995e231 < x

    1. Initial program 5.1%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip3--5.1%

        \[\leadsto \color{blue}{\frac{{\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
      2. div-inv5.1%

        \[\leadsto \color{blue}{\left({\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
      3. rem-cube-cbrt3.0%

        \[\leadsto \left(\color{blue}{\left(x + 1\right)} - {\left(\sqrt[3]{x}\right)}^{3}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      4. rem-cube-cbrt5.1%

        \[\leadsto \left(\left(x + 1\right) - \color{blue}{x}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      5. +-commutative5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right) + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}}} \]
      6. distribute-rgt-out5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x + 1}\right)} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}} \]
      7. +-commutative5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\sqrt[3]{x} \cdot \color{blue}{\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right)} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}} \]
      8. fma-define5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right)}} \]
      9. add-exp-log5.1%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, \color{blue}{e^{\log \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right)}}\right)} \]
    4. Applied egg-rr5.1%

      \[\leadsto \color{blue}{\left(\left(x + 1\right) - x\right) \cdot \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)}} \]
    5. Step-by-step derivation
      1. associate-*r/5.1%

        \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot 1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)}} \]
      2. *-rgt-identity5.1%

        \[\leadsto \frac{\color{blue}{\left(x + 1\right) - x}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      3. +-commutative5.1%

        \[\leadsto \frac{\color{blue}{\left(1 + x\right)} - x}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      4. associate--l+91.3%

        \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      5. +-inverses91.3%

        \[\leadsto \frac{1 + \color{blue}{0}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      6. metadata-eval91.3%

        \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      7. +-commutative91.3%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{\color{blue}{1 + x}} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      8. exp-prod90.5%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, \color{blue}{{\left(e^{0.6666666666666666}\right)}^{\left(\mathsf{log1p}\left(x\right)\right)}}\right)} \]
    6. Simplified90.5%

      \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, {\left(e^{0.6666666666666666}\right)}^{\left(\mathsf{log1p}\left(x\right)\right)}\right)}} \]
    7. Taylor expanded in x around 0 20.0%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, \color{blue}{1}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification82.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.55 \cdot 10^{+231}:\\ \;\;\;\;\frac{1}{x} \cdot \frac{\mathsf{fma}\left(0.3333333333333333, {\left(\sqrt[3]{x}\right)}^{4}, \sqrt[3]{x \cdot -0.0013717421124828531}\right)}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, 1\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 58.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\ \;\;\;\;\frac{\sqrt[3]{x} \cdot -0.1111111111111111 + 0.3333333333333333 \cdot \left(x \cdot \sqrt[3]{x}\right)}{{x}^{2}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, 1\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.35e+154)
   (/
    (+ (* (cbrt x) -0.1111111111111111) (* 0.3333333333333333 (* x (cbrt x))))
    (pow x 2.0))
   (/ 1.0 (fma (cbrt x) (+ (cbrt x) (cbrt (+ x 1.0))) 1.0))))
double code(double x) {
	double tmp;
	if (x <= 1.35e+154) {
		tmp = ((cbrt(x) * -0.1111111111111111) + (0.3333333333333333 * (x * cbrt(x)))) / pow(x, 2.0);
	} else {
		tmp = 1.0 / fma(cbrt(x), (cbrt(x) + cbrt((x + 1.0))), 1.0);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.35e+154)
		tmp = Float64(Float64(Float64(cbrt(x) * -0.1111111111111111) + Float64(0.3333333333333333 * Float64(x * cbrt(x)))) / (x ^ 2.0));
	else
		tmp = Float64(1.0 / fma(cbrt(x), Float64(cbrt(x) + cbrt(Float64(x + 1.0))), 1.0));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.35e+154], N[(N[(N[(N[Power[x, 1/3], $MachinePrecision] * -0.1111111111111111), $MachinePrecision] + N[(0.3333333333333333 * N[(x * N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Power[x, 1/3], $MachinePrecision] * N[(N[Power[x, 1/3], $MachinePrecision] + N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\
\;\;\;\;\frac{\sqrt[3]{x} \cdot -0.1111111111111111 + 0.3333333333333333 \cdot \left(x \cdot \sqrt[3]{x}\right)}{{x}^{2}}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, 1\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.35000000000000003e154

    1. Initial program 5.9%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 48.8%

      \[\leadsto \color{blue}{\frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \sqrt[3]{{x}^{4}}}{{x}^{2}}} \]
    4. Step-by-step derivation
      1. pow1/345.3%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{\left({x}^{4}\right)}^{0.3333333333333333}}}{{x}^{2}} \]
      2. pow-pow90.1%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{x}^{\left(4 \cdot 0.3333333333333333\right)}}}{{x}^{2}} \]
      3. metadata-eval90.1%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot {x}^{\color{blue}{1.3333333333333333}}}{{x}^{2}} \]
    5. Applied egg-rr90.1%

      \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{x}^{1.3333333333333333}}}{{x}^{2}} \]
    6. Step-by-step derivation
      1. metadata-eval90.1%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot {x}^{\color{blue}{\left(0.3333333333333333 \cdot 4\right)}}}{{x}^{2}} \]
      2. pow-pow90.1%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{{\left({x}^{0.3333333333333333}\right)}^{4}}}{{x}^{2}} \]
      3. pow1/397.3%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot {\color{blue}{\left(\sqrt[3]{x}\right)}}^{4}}{{x}^{2}} \]
      4. metadata-eval97.3%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot {\left(\sqrt[3]{x}\right)}^{\color{blue}{\left(2 \cdot 2\right)}}}{{x}^{2}} \]
      5. pow-sqr97.3%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{\left({\left(\sqrt[3]{x}\right)}^{2} \cdot {\left(\sqrt[3]{x}\right)}^{2}\right)}}{{x}^{2}} \]
      6. unpow297.3%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \left(\color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)} \cdot {\left(\sqrt[3]{x}\right)}^{2}\right)}{{x}^{2}} \]
      7. associate-*l*97.2%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{\left(\sqrt[3]{x} \cdot \left(\sqrt[3]{x} \cdot {\left(\sqrt[3]{x}\right)}^{2}\right)\right)}}{{x}^{2}} \]
      8. unpow297.2%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \left(\sqrt[3]{x} \cdot \left(\sqrt[3]{x} \cdot \color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}\right)\right)}{{x}^{2}} \]
      9. cube-mult97.3%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \left(\sqrt[3]{x} \cdot \color{blue}{{\left(\sqrt[3]{x}\right)}^{3}}\right)}{{x}^{2}} \]
      10. rem-cube-cbrt98.6%

        \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \left(\sqrt[3]{x} \cdot \color{blue}{x}\right)}{{x}^{2}} \]
    7. Applied egg-rr98.6%

      \[\leadsto \frac{-0.1111111111111111 \cdot \sqrt[3]{x} + 0.3333333333333333 \cdot \color{blue}{\left(\sqrt[3]{x} \cdot x\right)}}{{x}^{2}} \]

    if 1.35000000000000003e154 < x

    1. Initial program 4.7%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip3--4.7%

        \[\leadsto \color{blue}{\frac{{\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
      2. div-inv4.7%

        \[\leadsto \color{blue}{\left({\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
      3. rem-cube-cbrt3.2%

        \[\leadsto \left(\color{blue}{\left(x + 1\right)} - {\left(\sqrt[3]{x}\right)}^{3}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      4. rem-cube-cbrt4.7%

        \[\leadsto \left(\left(x + 1\right) - \color{blue}{x}\right) \cdot \frac{1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      5. +-commutative4.7%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right) + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}}} \]
      6. distribute-rgt-out4.7%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x + 1}\right)} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}} \]
      7. +-commutative4.7%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\sqrt[3]{x} \cdot \color{blue}{\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right)} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}} \]
      8. fma-define4.7%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\color{blue}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, \sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right)}} \]
      9. add-exp-log4.7%

        \[\leadsto \left(\left(x + 1\right) - x\right) \cdot \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, \color{blue}{e^{\log \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right)}}\right)} \]
    4. Applied egg-rr4.7%

      \[\leadsto \color{blue}{\left(\left(x + 1\right) - x\right) \cdot \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)}} \]
    5. Step-by-step derivation
      1. associate-*r/4.7%

        \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot 1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)}} \]
      2. *-rgt-identity4.7%

        \[\leadsto \frac{\color{blue}{\left(x + 1\right) - x}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      3. +-commutative4.7%

        \[\leadsto \frac{\color{blue}{\left(1 + x\right)} - x}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      4. associate--l+91.8%

        \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      5. +-inverses91.8%

        \[\leadsto \frac{1 + \color{blue}{0}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      6. metadata-eval91.8%

        \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x + 1} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      7. +-commutative91.8%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{\color{blue}{1 + x}} + \sqrt[3]{x}, e^{0.6666666666666666 \cdot \mathsf{log1p}\left(x\right)}\right)} \]
      8. exp-prod90.9%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, \color{blue}{{\left(e^{0.6666666666666666}\right)}^{\left(\mathsf{log1p}\left(x\right)\right)}}\right)} \]
    6. Simplified90.9%

      \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, {\left(e^{0.6666666666666666}\right)}^{\left(\mathsf{log1p}\left(x\right)\right)}\right)}} \]
    7. Taylor expanded in x around 0 20.0%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{1 + x} + \sqrt[3]{x}, \color{blue}{1}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification62.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\ \;\;\;\;\frac{\sqrt[3]{x} \cdot -0.1111111111111111 + 0.3333333333333333 \cdot \left(x \cdot \sqrt[3]{x}\right)}{{x}^{2}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, 1\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 49.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}} \end{array} \]
(FPCore (x)
 :precision binary64
 (* 0.3333333333333333 (cbrt (/ 1.0 (pow x 2.0)))))
double code(double x) {
	return 0.3333333333333333 * cbrt((1.0 / pow(x, 2.0)));
}
public static double code(double x) {
	return 0.3333333333333333 * Math.cbrt((1.0 / Math.pow(x, 2.0)));
}
function code(x)
	return Float64(0.3333333333333333 * cbrt(Float64(1.0 / (x ^ 2.0))))
end
code[x_] := N[(0.3333333333333333 * N[Power[N[(1.0 / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}
\end{array}
Derivation
  1. Initial program 5.3%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 54.9%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Final simplification54.9%

    \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}} \]
  5. Add Preprocessing

Alternative 6: 5.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt[3]{x} - {x}^{0.3333333333333333} \end{array} \]
(FPCore (x) :precision binary64 (- (cbrt x) (pow x 0.3333333333333333)))
double code(double x) {
	return cbrt(x) - pow(x, 0.3333333333333333);
}
public static double code(double x) {
	return Math.cbrt(x) - Math.pow(x, 0.3333333333333333);
}
function code(x)
	return Float64(cbrt(x) - (x ^ 0.3333333333333333))
end
code[x_] := N[(N[Power[x, 1/3], $MachinePrecision] - N[Power[x, 0.3333333333333333], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{x} - {x}^{0.3333333333333333}
\end{array}
Derivation
  1. Initial program 5.3%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 4.1%

    \[\leadsto \color{blue}{\sqrt[3]{x}} - \sqrt[3]{x} \]
  4. Step-by-step derivation
    1. pow1/35.9%

      \[\leadsto \sqrt[3]{x} - \color{blue}{{x}^{0.3333333333333333}} \]
  5. Applied egg-rr5.9%

    \[\leadsto \sqrt[3]{x} - \color{blue}{{x}^{0.3333333333333333}} \]
  6. Final simplification5.9%

    \[\leadsto \sqrt[3]{x} - {x}^{0.3333333333333333} \]
  7. Add Preprocessing

Alternative 7: 5.3% accurate, 2.0× speedup?

\[\begin{array}{l} \\ 1 + \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (+ 1.0 (cbrt x)))
double code(double x) {
	return 1.0 + cbrt(x);
}
public static double code(double x) {
	return 1.0 + Math.cbrt(x);
}
function code(x)
	return Float64(1.0 + cbrt(x))
end
code[x_] := N[(1.0 + N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 + \sqrt[3]{x}
\end{array}
Derivation
  1. Initial program 5.3%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 1.8%

    \[\leadsto \color{blue}{1 - \sqrt[3]{x}} \]
  4. Step-by-step derivation
    1. sub-neg1.8%

      \[\leadsto \color{blue}{1 + \left(-\sqrt[3]{x}\right)} \]
    2. rem-square-sqrt0.0%

      \[\leadsto 1 + \color{blue}{\sqrt{-\sqrt[3]{x}} \cdot \sqrt{-\sqrt[3]{x}}} \]
    3. fabs-sqr0.0%

      \[\leadsto 1 + \color{blue}{\left|\sqrt{-\sqrt[3]{x}} \cdot \sqrt{-\sqrt[3]{x}}\right|} \]
    4. rem-square-sqrt5.4%

      \[\leadsto 1 + \left|\color{blue}{-\sqrt[3]{x}}\right| \]
    5. fabs-neg5.4%

      \[\leadsto 1 + \color{blue}{\left|\sqrt[3]{x}\right|} \]
    6. unpow1/35.4%

      \[\leadsto 1 + \left|\color{blue}{{x}^{0.3333333333333333}}\right| \]
    7. metadata-eval5.4%

      \[\leadsto 1 + \left|{x}^{\color{blue}{\left(2 \cdot 0.16666666666666666\right)}}\right| \]
    8. pow-sqr5.4%

      \[\leadsto 1 + \left|\color{blue}{{x}^{0.16666666666666666} \cdot {x}^{0.16666666666666666}}\right| \]
    9. fabs-sqr5.4%

      \[\leadsto 1 + \color{blue}{{x}^{0.16666666666666666} \cdot {x}^{0.16666666666666666}} \]
    10. pow-sqr5.4%

      \[\leadsto 1 + \color{blue}{{x}^{\left(2 \cdot 0.16666666666666666\right)}} \]
    11. metadata-eval5.4%

      \[\leadsto 1 + {x}^{\color{blue}{0.3333333333333333}} \]
    12. unpow1/35.4%

      \[\leadsto 1 + \color{blue}{\sqrt[3]{x}} \]
  5. Simplified5.4%

    \[\leadsto \color{blue}{1 + \sqrt[3]{x}} \]
  6. Final simplification5.4%

    \[\leadsto 1 + \sqrt[3]{x} \]
  7. Add Preprocessing

Developer target: 98.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{x + 1}\\ \frac{1}{\left(t\_0 \cdot t\_0 + \sqrt[3]{x} \cdot t\_0\right) + \sqrt[3]{x} \cdot \sqrt[3]{x}} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (cbrt (+ x 1.0))))
   (/ 1.0 (+ (+ (* t_0 t_0) (* (cbrt x) t_0)) (* (cbrt x) (cbrt x))))))
double code(double x) {
	double t_0 = cbrt((x + 1.0));
	return 1.0 / (((t_0 * t_0) + (cbrt(x) * t_0)) + (cbrt(x) * cbrt(x)));
}
public static double code(double x) {
	double t_0 = Math.cbrt((x + 1.0));
	return 1.0 / (((t_0 * t_0) + (Math.cbrt(x) * t_0)) + (Math.cbrt(x) * Math.cbrt(x)));
}
function code(x)
	t_0 = cbrt(Float64(x + 1.0))
	return Float64(1.0 / Float64(Float64(Float64(t_0 * t_0) + Float64(cbrt(x) * t_0)) + Float64(cbrt(x) * cbrt(x))))
end
code[x_] := Block[{t$95$0 = N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision]}, N[(1.0 / N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt[3]{x + 1}\\
\frac{1}{\left(t\_0 \cdot t\_0 + \sqrt[3]{x} \cdot t\_0\right) + \sqrt[3]{x} \cdot \sqrt[3]{x}}
\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024081 
(FPCore (x)
  :name "2cbrt (problem 3.3.4)"
  :precision binary64
  :pre (and (> x 1.0) (< x 1e+308))

  :alt
  (/ 1.0 (+ (+ (* (cbrt (+ x 1.0)) (cbrt (+ x 1.0))) (* (cbrt x) (cbrt (+ x 1.0)))) (* (cbrt x) (cbrt x))))

  (- (cbrt (+ x 1.0)) (cbrt x)))