2-ancestry mixing, zero discriminant

Percentage Accurate: 76.0% → 98.6%
Time: 3.0s
Alternatives: 5
Speedup: 1.0×

Specification

?
\[\sqrt[3]{\frac{g}{2 \cdot a}} \]
(FPCore (g a) :precision binary64 (cbrt (/ g (* 2.0 a))))
double code(double g, double a) {
	return cbrt((g / (2.0 * a)));
}
public static double code(double g, double a) {
	return Math.cbrt((g / (2.0 * a)));
}
function code(g, a)
	return cbrt(Float64(g / Float64(2.0 * a)))
end
code[g_, a_] := N[Power[N[(g / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]
\sqrt[3]{\frac{g}{2 \cdot a}}

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 5 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: 76.0% accurate, 1.0× speedup?

\[\sqrt[3]{\frac{g}{2 \cdot a}} \]
(FPCore (g a) :precision binary64 (cbrt (/ g (* 2.0 a))))
double code(double g, double a) {
	return cbrt((g / (2.0 * a)));
}
public static double code(double g, double a) {
	return Math.cbrt((g / (2.0 * a)));
}
function code(g, a)
	return cbrt(Float64(g / Float64(2.0 * a)))
end
code[g_, a_] := N[Power[N[(g / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]
\sqrt[3]{\frac{g}{2 \cdot a}}

Alternative 1: 98.6% accurate, 0.6× speedup?

\[\frac{\sqrt[3]{g}}{\sqrt[3]{a + a}} \]
(FPCore (g a) :precision binary64 (/ (cbrt g) (cbrt (+ a a))))
double code(double g, double a) {
	return cbrt(g) / cbrt((a + a));
}
public static double code(double g, double a) {
	return Math.cbrt(g) / Math.cbrt((a + a));
}
function code(g, a)
	return Float64(cbrt(g) / cbrt(Float64(a + a)))
end
code[g_, a_] := N[(N[Power[g, 1/3], $MachinePrecision] / N[Power[N[(a + a), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]
\frac{\sqrt[3]{g}}{\sqrt[3]{a + a}}
Derivation
  1. Initial program 76.0%

    \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
  2. Step-by-step derivation
    1. lift-cbrt.f64N/A

      \[\leadsto \color{blue}{\sqrt[3]{\frac{g}{2 \cdot a}}} \]
    2. lift-/.f64N/A

      \[\leadsto \sqrt[3]{\color{blue}{\frac{g}{2 \cdot a}}} \]
    3. cbrt-divN/A

      \[\leadsto \color{blue}{\frac{\sqrt[3]{g}}{\sqrt[3]{2 \cdot a}}} \]
    4. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\sqrt[3]{g}}{\sqrt[3]{2 \cdot a}}} \]
    5. lower-cbrt.f64N/A

      \[\leadsto \frac{\color{blue}{\sqrt[3]{g}}}{\sqrt[3]{2 \cdot a}} \]
    6. lower-cbrt.f6498.6%

      \[\leadsto \frac{\sqrt[3]{g}}{\color{blue}{\sqrt[3]{2 \cdot a}}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\sqrt[3]{g}}{\sqrt[3]{\color{blue}{2 \cdot a}}} \]
    8. count-2-revN/A

      \[\leadsto \frac{\sqrt[3]{g}}{\sqrt[3]{\color{blue}{a + a}}} \]
    9. lower-+.f6498.6%

      \[\leadsto \frac{\sqrt[3]{g}}{\sqrt[3]{\color{blue}{a + a}}} \]
  3. Applied rewrites98.6%

    \[\leadsto \color{blue}{\frac{\sqrt[3]{g}}{\sqrt[3]{a + a}}} \]
  4. Add Preprocessing

Alternative 2: 96.6% accurate, 0.2× speedup?

\[\begin{array}{l} t_0 := \log \left(\left|g\right|\right)\\ t_1 := \log \left(\left|a\right| + \left|a\right|\right)\\ t_2 := \sqrt[3]{\frac{\left|g\right|}{2 \cdot \left|a\right|}}\\ \mathsf{copysign}\left(1, g\right) \cdot \left(\mathsf{copysign}\left(1, a\right) \cdot \begin{array}{l} \mathbf{if}\;t\_2 \leq 4 \cdot 10^{-104}:\\ \;\;\;\;e^{0.3333333333333333 \cdot t\_0 - t\_1 \cdot 0.3333333333333333}\\ \mathbf{elif}\;t\_2 \leq 5 \cdot 10^{+102}:\\ \;\;\;\;\sqrt[3]{\frac{0.5}{\left|a\right|} \cdot \left|g\right|}\\ \mathbf{else}:\\ \;\;\;\;e^{\left(t\_0 - t\_1\right) \cdot 0.3333333333333333}\\ \end{array}\right) \end{array} \]
(FPCore (g a)
 :precision binary64
 (let* ((t_0 (log (fabs g)))
        (t_1 (log (+ (fabs a) (fabs a))))
        (t_2 (cbrt (/ (fabs g) (* 2.0 (fabs a))))))
   (*
    (copysign 1.0 g)
    (*
     (copysign 1.0 a)
     (if (<= t_2 4e-104)
       (exp (- (* 0.3333333333333333 t_0) (* t_1 0.3333333333333333)))
       (if (<= t_2 5e+102)
         (cbrt (* (/ 0.5 (fabs a)) (fabs g)))
         (exp (* (- t_0 t_1) 0.3333333333333333))))))))
double code(double g, double a) {
	double t_0 = log(fabs(g));
	double t_1 = log((fabs(a) + fabs(a)));
	double t_2 = cbrt((fabs(g) / (2.0 * fabs(a))));
	double tmp;
	if (t_2 <= 4e-104) {
		tmp = exp(((0.3333333333333333 * t_0) - (t_1 * 0.3333333333333333)));
	} else if (t_2 <= 5e+102) {
		tmp = cbrt(((0.5 / fabs(a)) * fabs(g)));
	} else {
		tmp = exp(((t_0 - t_1) * 0.3333333333333333));
	}
	return copysign(1.0, g) * (copysign(1.0, a) * tmp);
}
public static double code(double g, double a) {
	double t_0 = Math.log(Math.abs(g));
	double t_1 = Math.log((Math.abs(a) + Math.abs(a)));
	double t_2 = Math.cbrt((Math.abs(g) / (2.0 * Math.abs(a))));
	double tmp;
	if (t_2 <= 4e-104) {
		tmp = Math.exp(((0.3333333333333333 * t_0) - (t_1 * 0.3333333333333333)));
	} else if (t_2 <= 5e+102) {
		tmp = Math.cbrt(((0.5 / Math.abs(a)) * Math.abs(g)));
	} else {
		tmp = Math.exp(((t_0 - t_1) * 0.3333333333333333));
	}
	return Math.copySign(1.0, g) * (Math.copySign(1.0, a) * tmp);
}
function code(g, a)
	t_0 = log(abs(g))
	t_1 = log(Float64(abs(a) + abs(a)))
	t_2 = cbrt(Float64(abs(g) / Float64(2.0 * abs(a))))
	tmp = 0.0
	if (t_2 <= 4e-104)
		tmp = exp(Float64(Float64(0.3333333333333333 * t_0) - Float64(t_1 * 0.3333333333333333)));
	elseif (t_2 <= 5e+102)
		tmp = cbrt(Float64(Float64(0.5 / abs(a)) * abs(g)));
	else
		tmp = exp(Float64(Float64(t_0 - t_1) * 0.3333333333333333));
	end
	return Float64(copysign(1.0, g) * Float64(copysign(1.0, a) * tmp))
end
code[g_, a_] := Block[{t$95$0 = N[Log[N[Abs[g], $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[Log[N[(N[Abs[a], $MachinePrecision] + N[Abs[a], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[Power[N[(N[Abs[g], $MachinePrecision] / N[(2.0 * N[Abs[a], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]}, N[(N[With[{TMP1 = Abs[1.0], TMP2 = Sign[g]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision] * N[(N[With[{TMP1 = Abs[1.0], TMP2 = Sign[a]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision] * If[LessEqual[t$95$2, 4e-104], N[Exp[N[(N[(0.3333333333333333 * t$95$0), $MachinePrecision] - N[(t$95$1 * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], If[LessEqual[t$95$2, 5e+102], N[Power[N[(N[(0.5 / N[Abs[a], $MachinePrecision]), $MachinePrecision] * N[Abs[g], $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision], N[Exp[N[(N[(t$95$0 - t$95$1), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]], $MachinePrecision]]]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
t_0 := \log \left(\left|g\right|\right)\\
t_1 := \log \left(\left|a\right| + \left|a\right|\right)\\
t_2 := \sqrt[3]{\frac{\left|g\right|}{2 \cdot \left|a\right|}}\\
\mathsf{copysign}\left(1, g\right) \cdot \left(\mathsf{copysign}\left(1, a\right) \cdot \begin{array}{l}
\mathbf{if}\;t\_2 \leq 4 \cdot 10^{-104}:\\
\;\;\;\;e^{0.3333333333333333 \cdot t\_0 - t\_1 \cdot 0.3333333333333333}\\

\mathbf{elif}\;t\_2 \leq 5 \cdot 10^{+102}:\\
\;\;\;\;\sqrt[3]{\frac{0.5}{\left|a\right|} \cdot \left|g\right|}\\

\mathbf{else}:\\
\;\;\;\;e^{\left(t\_0 - t\_1\right) \cdot 0.3333333333333333}\\


\end{array}\right)
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (cbrt.f64 (/.f64 g (*.f64 #s(literal 2 binary64) a))) < 3.99999999999999971e-104

    1. Initial program 76.0%

      \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
    2. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \color{blue}{\sqrt[3]{\frac{g}{2 \cdot a}}} \]
      2. pow1/3N/A

        \[\leadsto \color{blue}{{\left(\frac{g}{2 \cdot a}\right)}^{\frac{1}{3}}} \]
      3. pow-to-expN/A

        \[\leadsto \color{blue}{e^{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      4. lower-unsound-exp.f64N/A

        \[\leadsto \color{blue}{e^{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      5. lower-unsound-*.f64N/A

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      6. lower-unsound-log.f6435.7%

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{2 \cdot a}\right)} \cdot 0.3333333333333333} \]
      7. lift-*.f64N/A

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{2 \cdot a}}\right) \cdot \frac{1}{3}} \]
      8. count-2-revN/A

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{a + a}}\right) \cdot \frac{1}{3}} \]
      9. lower-+.f6435.7%

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{a + a}}\right) \cdot 0.3333333333333333} \]
    3. Applied rewrites35.7%

      \[\leadsto \color{blue}{e^{\log \left(\frac{g}{a + a}\right) \cdot 0.3333333333333333}} \]
    4. Step-by-step derivation
      1. lift-log.f64N/A

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{a + a}\right)} \cdot \frac{1}{3}} \]
      2. lift-/.f64N/A

        \[\leadsto e^{\log \color{blue}{\left(\frac{g}{a + a}\right)} \cdot \frac{1}{3}} \]
      3. log-divN/A

        \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot \frac{1}{3}} \]
      4. lower-unsound--.f64N/A

        \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot \frac{1}{3}} \]
      5. lower-unsound-log.f64N/A

        \[\leadsto e^{\left(\color{blue}{\log g} - \log \left(a + a\right)\right) \cdot \frac{1}{3}} \]
      6. lower-unsound-log.f6422.7%

        \[\leadsto e^{\left(\log g - \color{blue}{\log \left(a + a\right)}\right) \cdot 0.3333333333333333} \]
    5. Applied rewrites22.7%

      \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot 0.3333333333333333} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right) \cdot \frac{1}{3}}} \]
      2. *-commutativeN/A

        \[\leadsto e^{\color{blue}{\frac{1}{3} \cdot \left(\log g - \log \left(a + a\right)\right)}} \]
      3. lift--.f64N/A

        \[\leadsto e^{\frac{1}{3} \cdot \color{blue}{\left(\log g - \log \left(a + a\right)\right)}} \]
      4. sub-flipN/A

        \[\leadsto e^{\frac{1}{3} \cdot \color{blue}{\left(\log g + \left(\mathsf{neg}\left(\log \left(a + a\right)\right)\right)\right)}} \]
      5. distribute-rgt-inN/A

        \[\leadsto e^{\color{blue}{\log g \cdot \frac{1}{3} + \left(\mathsf{neg}\left(\log \left(a + a\right)\right)\right) \cdot \frac{1}{3}}} \]
      6. fp-cancel-sub-signN/A

        \[\leadsto e^{\color{blue}{\log g \cdot \frac{1}{3} - \log \left(a + a\right) \cdot \frac{1}{3}}} \]
      7. lower--.f64N/A

        \[\leadsto e^{\color{blue}{\log g \cdot \frac{1}{3} - \log \left(a + a\right) \cdot \frac{1}{3}}} \]
      8. *-commutativeN/A

        \[\leadsto e^{\color{blue}{\frac{1}{3} \cdot \log g} - \log \left(a + a\right) \cdot \frac{1}{3}} \]
      9. lower-*.f64N/A

        \[\leadsto e^{\color{blue}{\frac{1}{3} \cdot \log g} - \log \left(a + a\right) \cdot \frac{1}{3}} \]
      10. lower-*.f6422.7%

        \[\leadsto e^{0.3333333333333333 \cdot \log g - \color{blue}{\log \left(a + a\right) \cdot 0.3333333333333333}} \]
    7. Applied rewrites22.7%

      \[\leadsto e^{\color{blue}{0.3333333333333333 \cdot \log g - \log \left(a + a\right) \cdot 0.3333333333333333}} \]

    if 3.99999999999999971e-104 < (cbrt.f64 (/.f64 g (*.f64 #s(literal 2 binary64) a))) < 5e102

    1. Initial program 76.0%

      \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{g}{2 \cdot a}}} \]
      2. mult-flipN/A

        \[\leadsto \sqrt[3]{\color{blue}{g \cdot \frac{1}{2 \cdot a}}} \]
      3. *-commutativeN/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{1}{2 \cdot a} \cdot g}} \]
      4. lower-*.f64N/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{1}{2 \cdot a} \cdot g}} \]
      5. lift-*.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{\color{blue}{2 \cdot a}} \cdot g} \]
      6. associate-/r*N/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{\frac{1}{2}}{a}} \cdot g} \]
      7. lower-/.f64N/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{\frac{1}{2}}{a}} \cdot g} \]
      8. metadata-eval76.1%

        \[\leadsto \sqrt[3]{\frac{\color{blue}{0.5}}{a} \cdot g} \]
    3. Applied rewrites76.1%

      \[\leadsto \sqrt[3]{\color{blue}{\frac{0.5}{a} \cdot g}} \]

    if 5e102 < (cbrt.f64 (/.f64 g (*.f64 #s(literal 2 binary64) a)))

    1. Initial program 76.0%

      \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
    2. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \color{blue}{\sqrt[3]{\frac{g}{2 \cdot a}}} \]
      2. pow1/3N/A

        \[\leadsto \color{blue}{{\left(\frac{g}{2 \cdot a}\right)}^{\frac{1}{3}}} \]
      3. pow-to-expN/A

        \[\leadsto \color{blue}{e^{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      4. lower-unsound-exp.f64N/A

        \[\leadsto \color{blue}{e^{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      5. lower-unsound-*.f64N/A

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      6. lower-unsound-log.f6435.7%

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{2 \cdot a}\right)} \cdot 0.3333333333333333} \]
      7. lift-*.f64N/A

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{2 \cdot a}}\right) \cdot \frac{1}{3}} \]
      8. count-2-revN/A

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{a + a}}\right) \cdot \frac{1}{3}} \]
      9. lower-+.f6435.7%

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{a + a}}\right) \cdot 0.3333333333333333} \]
    3. Applied rewrites35.7%

      \[\leadsto \color{blue}{e^{\log \left(\frac{g}{a + a}\right) \cdot 0.3333333333333333}} \]
    4. Step-by-step derivation
      1. lift-log.f64N/A

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{a + a}\right)} \cdot \frac{1}{3}} \]
      2. lift-/.f64N/A

        \[\leadsto e^{\log \color{blue}{\left(\frac{g}{a + a}\right)} \cdot \frac{1}{3}} \]
      3. log-divN/A

        \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot \frac{1}{3}} \]
      4. lower-unsound--.f64N/A

        \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot \frac{1}{3}} \]
      5. lower-unsound-log.f64N/A

        \[\leadsto e^{\left(\color{blue}{\log g} - \log \left(a + a\right)\right) \cdot \frac{1}{3}} \]
      6. lower-unsound-log.f6422.7%

        \[\leadsto e^{\left(\log g - \color{blue}{\log \left(a + a\right)}\right) \cdot 0.3333333333333333} \]
    5. Applied rewrites22.7%

      \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot 0.3333333333333333} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 3: 96.6% accurate, 0.2× speedup?

\[\begin{array}{l} t_0 := e^{\left(\log \left(\left|g\right|\right) - \log \left(\left|a\right| + \left|a\right|\right)\right) \cdot 0.3333333333333333}\\ t_1 := \sqrt[3]{\frac{\left|g\right|}{2 \cdot \left|a\right|}}\\ \mathsf{copysign}\left(1, g\right) \cdot \left(\mathsf{copysign}\left(1, a\right) \cdot \begin{array}{l} \mathbf{if}\;t\_1 \leq 2 \cdot 10^{-105}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq 5 \cdot 10^{+102}:\\ \;\;\;\;\sqrt[3]{\frac{0.5}{\left|a\right|} \cdot \left|g\right|}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array}\right) \end{array} \]
(FPCore (g a)
 :precision binary64
 (let* ((t_0
         (exp
          (*
           (- (log (fabs g)) (log (+ (fabs a) (fabs a))))
           0.3333333333333333)))
        (t_1 (cbrt (/ (fabs g) (* 2.0 (fabs a))))))
   (*
    (copysign 1.0 g)
    (*
     (copysign 1.0 a)
     (if (<= t_1 2e-105)
       t_0
       (if (<= t_1 5e+102) (cbrt (* (/ 0.5 (fabs a)) (fabs g))) t_0))))))
double code(double g, double a) {
	double t_0 = exp(((log(fabs(g)) - log((fabs(a) + fabs(a)))) * 0.3333333333333333));
	double t_1 = cbrt((fabs(g) / (2.0 * fabs(a))));
	double tmp;
	if (t_1 <= 2e-105) {
		tmp = t_0;
	} else if (t_1 <= 5e+102) {
		tmp = cbrt(((0.5 / fabs(a)) * fabs(g)));
	} else {
		tmp = t_0;
	}
	return copysign(1.0, g) * (copysign(1.0, a) * tmp);
}
public static double code(double g, double a) {
	double t_0 = Math.exp(((Math.log(Math.abs(g)) - Math.log((Math.abs(a) + Math.abs(a)))) * 0.3333333333333333));
	double t_1 = Math.cbrt((Math.abs(g) / (2.0 * Math.abs(a))));
	double tmp;
	if (t_1 <= 2e-105) {
		tmp = t_0;
	} else if (t_1 <= 5e+102) {
		tmp = Math.cbrt(((0.5 / Math.abs(a)) * Math.abs(g)));
	} else {
		tmp = t_0;
	}
	return Math.copySign(1.0, g) * (Math.copySign(1.0, a) * tmp);
}
function code(g, a)
	t_0 = exp(Float64(Float64(log(abs(g)) - log(Float64(abs(a) + abs(a)))) * 0.3333333333333333))
	t_1 = cbrt(Float64(abs(g) / Float64(2.0 * abs(a))))
	tmp = 0.0
	if (t_1 <= 2e-105)
		tmp = t_0;
	elseif (t_1 <= 5e+102)
		tmp = cbrt(Float64(Float64(0.5 / abs(a)) * abs(g)));
	else
		tmp = t_0;
	end
	return Float64(copysign(1.0, g) * Float64(copysign(1.0, a) * tmp))
end
code[g_, a_] := Block[{t$95$0 = N[Exp[N[(N[(N[Log[N[Abs[g], $MachinePrecision]], $MachinePrecision] - N[Log[N[(N[Abs[a], $MachinePrecision] + N[Abs[a], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[Power[N[(N[Abs[g], $MachinePrecision] / N[(2.0 * N[Abs[a], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]}, N[(N[With[{TMP1 = Abs[1.0], TMP2 = Sign[g]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision] * N[(N[With[{TMP1 = Abs[1.0], TMP2 = Sign[a]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision] * If[LessEqual[t$95$1, 2e-105], t$95$0, If[LessEqual[t$95$1, 5e+102], N[Power[N[(N[(0.5 / N[Abs[a], $MachinePrecision]), $MachinePrecision] * N[Abs[g], $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision], t$95$0]]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
t_0 := e^{\left(\log \left(\left|g\right|\right) - \log \left(\left|a\right| + \left|a\right|\right)\right) \cdot 0.3333333333333333}\\
t_1 := \sqrt[3]{\frac{\left|g\right|}{2 \cdot \left|a\right|}}\\
\mathsf{copysign}\left(1, g\right) \cdot \left(\mathsf{copysign}\left(1, a\right) \cdot \begin{array}{l}
\mathbf{if}\;t\_1 \leq 2 \cdot 10^{-105}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;t\_1 \leq 5 \cdot 10^{+102}:\\
\;\;\;\;\sqrt[3]{\frac{0.5}{\left|a\right|} \cdot \left|g\right|}\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}\right)
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (cbrt.f64 (/.f64 g (*.f64 #s(literal 2 binary64) a))) < 1.99999999999999993e-105 or 5e102 < (cbrt.f64 (/.f64 g (*.f64 #s(literal 2 binary64) a)))

    1. Initial program 76.0%

      \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
    2. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \color{blue}{\sqrt[3]{\frac{g}{2 \cdot a}}} \]
      2. pow1/3N/A

        \[\leadsto \color{blue}{{\left(\frac{g}{2 \cdot a}\right)}^{\frac{1}{3}}} \]
      3. pow-to-expN/A

        \[\leadsto \color{blue}{e^{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      4. lower-unsound-exp.f64N/A

        \[\leadsto \color{blue}{e^{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      5. lower-unsound-*.f64N/A

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{2 \cdot a}\right) \cdot \frac{1}{3}}} \]
      6. lower-unsound-log.f6435.7%

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{2 \cdot a}\right)} \cdot 0.3333333333333333} \]
      7. lift-*.f64N/A

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{2 \cdot a}}\right) \cdot \frac{1}{3}} \]
      8. count-2-revN/A

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{a + a}}\right) \cdot \frac{1}{3}} \]
      9. lower-+.f6435.7%

        \[\leadsto e^{\log \left(\frac{g}{\color{blue}{a + a}}\right) \cdot 0.3333333333333333} \]
    3. Applied rewrites35.7%

      \[\leadsto \color{blue}{e^{\log \left(\frac{g}{a + a}\right) \cdot 0.3333333333333333}} \]
    4. Step-by-step derivation
      1. lift-log.f64N/A

        \[\leadsto e^{\color{blue}{\log \left(\frac{g}{a + a}\right)} \cdot \frac{1}{3}} \]
      2. lift-/.f64N/A

        \[\leadsto e^{\log \color{blue}{\left(\frac{g}{a + a}\right)} \cdot \frac{1}{3}} \]
      3. log-divN/A

        \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot \frac{1}{3}} \]
      4. lower-unsound--.f64N/A

        \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot \frac{1}{3}} \]
      5. lower-unsound-log.f64N/A

        \[\leadsto e^{\left(\color{blue}{\log g} - \log \left(a + a\right)\right) \cdot \frac{1}{3}} \]
      6. lower-unsound-log.f6422.7%

        \[\leadsto e^{\left(\log g - \color{blue}{\log \left(a + a\right)}\right) \cdot 0.3333333333333333} \]
    5. Applied rewrites22.7%

      \[\leadsto e^{\color{blue}{\left(\log g - \log \left(a + a\right)\right)} \cdot 0.3333333333333333} \]

    if 1.99999999999999993e-105 < (cbrt.f64 (/.f64 g (*.f64 #s(literal 2 binary64) a))) < 5e102

    1. Initial program 76.0%

      \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{g}{2 \cdot a}}} \]
      2. mult-flipN/A

        \[\leadsto \sqrt[3]{\color{blue}{g \cdot \frac{1}{2 \cdot a}}} \]
      3. *-commutativeN/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{1}{2 \cdot a} \cdot g}} \]
      4. lower-*.f64N/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{1}{2 \cdot a} \cdot g}} \]
      5. lift-*.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{\color{blue}{2 \cdot a}} \cdot g} \]
      6. associate-/r*N/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{\frac{1}{2}}{a}} \cdot g} \]
      7. lower-/.f64N/A

        \[\leadsto \sqrt[3]{\color{blue}{\frac{\frac{1}{2}}{a}} \cdot g} \]
      8. metadata-eval76.1%

        \[\leadsto \sqrt[3]{\frac{\color{blue}{0.5}}{a} \cdot g} \]
    3. Applied rewrites76.1%

      \[\leadsto \sqrt[3]{\color{blue}{\frac{0.5}{a} \cdot g}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 76.1% accurate, 1.0× speedup?

\[\sqrt[3]{\frac{0.5}{a} \cdot g} \]
(FPCore (g a) :precision binary64 (cbrt (* (/ 0.5 a) g)))
double code(double g, double a) {
	return cbrt(((0.5 / a) * g));
}
public static double code(double g, double a) {
	return Math.cbrt(((0.5 / a) * g));
}
function code(g, a)
	return cbrt(Float64(Float64(0.5 / a) * g))
end
code[g_, a_] := N[Power[N[(N[(0.5 / a), $MachinePrecision] * g), $MachinePrecision], 1/3], $MachinePrecision]
\sqrt[3]{\frac{0.5}{a} \cdot g}
Derivation
  1. Initial program 76.0%

    \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
  2. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \sqrt[3]{\color{blue}{\frac{g}{2 \cdot a}}} \]
    2. mult-flipN/A

      \[\leadsto \sqrt[3]{\color{blue}{g \cdot \frac{1}{2 \cdot a}}} \]
    3. *-commutativeN/A

      \[\leadsto \sqrt[3]{\color{blue}{\frac{1}{2 \cdot a} \cdot g}} \]
    4. lower-*.f64N/A

      \[\leadsto \sqrt[3]{\color{blue}{\frac{1}{2 \cdot a} \cdot g}} \]
    5. lift-*.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{\color{blue}{2 \cdot a}} \cdot g} \]
    6. associate-/r*N/A

      \[\leadsto \sqrt[3]{\color{blue}{\frac{\frac{1}{2}}{a}} \cdot g} \]
    7. lower-/.f64N/A

      \[\leadsto \sqrt[3]{\color{blue}{\frac{\frac{1}{2}}{a}} \cdot g} \]
    8. metadata-eval76.1%

      \[\leadsto \sqrt[3]{\frac{\color{blue}{0.5}}{a} \cdot g} \]
  3. Applied rewrites76.1%

    \[\leadsto \sqrt[3]{\color{blue}{\frac{0.5}{a} \cdot g}} \]
  4. Add Preprocessing

Alternative 5: 76.0% accurate, 1.0× speedup?

\[\sqrt[3]{\frac{g}{a + a}} \]
(FPCore (g a) :precision binary64 (cbrt (/ g (+ a a))))
double code(double g, double a) {
	return cbrt((g / (a + a)));
}
public static double code(double g, double a) {
	return Math.cbrt((g / (a + a)));
}
function code(g, a)
	return cbrt(Float64(g / Float64(a + a)))
end
code[g_, a_] := N[Power[N[(g / N[(a + a), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]
\sqrt[3]{\frac{g}{a + a}}
Derivation
  1. Initial program 76.0%

    \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \sqrt[3]{\frac{g}{\color{blue}{2 \cdot a}}} \]
    2. count-2-revN/A

      \[\leadsto \sqrt[3]{\frac{g}{\color{blue}{a + a}}} \]
    3. lower-+.f6476.0%

      \[\leadsto \sqrt[3]{\frac{g}{\color{blue}{a + a}}} \]
  3. Applied rewrites76.0%

    \[\leadsto \sqrt[3]{\color{blue}{\frac{g}{a + a}}} \]
  4. Add Preprocessing

Reproduce

?
herbie shell --seed 2025188 
(FPCore (g a)
  :name "2-ancestry mixing, zero discriminant"
  :precision binary64
  (cbrt (/ g (* 2.0 a))))