2-ancestry mixing, zero discriminant

Percentage Accurate: 76.8% → 98.7%
Time: 3.7s
Alternatives: 5
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \sqrt[3]{\frac{g}{2 \cdot a}} \end{array} \]
(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]
\begin{array}{l}

\\
\sqrt[3]{\frac{g}{2 \cdot a}}
\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 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: 76.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt[3]{\frac{g}{2 \cdot a}} \end{array} \]
(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]
\begin{array}{l}

\\
\sqrt[3]{\frac{g}{2 \cdot a}}
\end{array}

Alternative 1: 98.7% accurate, 0.5× speedup?

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

\\
\frac{\sqrt[3]{0.5 \cdot g}}{\sqrt[3]{a}}
\end{array}
Derivation
  1. Initial program 75.4%

    \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
  2. Add Preprocessing
  3. 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. lift-*.f64N/A

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

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

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

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

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

      \[\leadsto \frac{\sqrt[3]{\color{blue}{\frac{g}{2}}}}{\sqrt[3]{a}} \]
    9. lower-cbrt.f6498.7

      \[\leadsto \frac{\sqrt[3]{\frac{g}{2}}}{\color{blue}{\sqrt[3]{a}}} \]
  4. Applied rewrites98.7%

    \[\leadsto \color{blue}{\frac{\sqrt[3]{\frac{g}{2}}}{\sqrt[3]{a}}} \]
  5. Taylor expanded in g around 0

    \[\leadsto \frac{\sqrt[3]{\color{blue}{\frac{1}{2} \cdot g}}}{\sqrt[3]{a}} \]
  6. Step-by-step derivation
    1. lower-*.f6498.7

      \[\leadsto \frac{\sqrt[3]{\color{blue}{0.5 \cdot g}}}{\sqrt[3]{a}} \]
  7. Applied rewrites98.7%

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

Alternative 2: 98.7% accurate, 0.5× speedup?

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

\\
\sqrt[3]{\frac{0.5}{a}} \cdot \sqrt[3]{g}
\end{array}
Derivation
  1. Initial program 75.4%

    \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
  2. Add Preprocessing
  3. Taylor expanded in g around 0

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

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

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

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

      \[\leadsto \sqrt[3]{\frac{1}{2}} \cdot \color{blue}{\sqrt[3]{\frac{g}{a}}} \]
    5. lower-/.f6475.4

      \[\leadsto \sqrt[3]{0.5} \cdot \sqrt[3]{\color{blue}{\frac{g}{a}}} \]
  5. Applied rewrites75.4%

    \[\leadsto \color{blue}{\sqrt[3]{0.5} \cdot \sqrt[3]{\frac{g}{a}}} \]
  6. Step-by-step derivation
    1. Applied rewrites98.5%

      \[\leadsto \sqrt[3]{0.5} \cdot \frac{\sqrt[3]{g}}{\color{blue}{\sqrt[3]{a}}} \]
    2. Step-by-step derivation
      1. Applied rewrites98.7%

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

      Alternative 3: 76.8% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \sqrt[3]{\frac{0.5}{a} \cdot g} \end{array} \]
      (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]
      
      \begin{array}{l}
      
      \\
      \sqrt[3]{\frac{0.5}{a} \cdot g}
      \end{array}
      
      Derivation
      1. Initial program 75.4%

        \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
      2. Add Preprocessing
      3. Taylor expanded in g around 0

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

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

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

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

          \[\leadsto \sqrt[3]{\frac{1}{2}} \cdot \color{blue}{\sqrt[3]{\frac{g}{a}}} \]
        5. lower-/.f6475.4

          \[\leadsto \sqrt[3]{0.5} \cdot \sqrt[3]{\color{blue}{\frac{g}{a}}} \]
      5. Applied rewrites75.4%

        \[\leadsto \color{blue}{\sqrt[3]{0.5} \cdot \sqrt[3]{\frac{g}{a}}} \]
      6. Step-by-step derivation
        1. Applied rewrites98.5%

          \[\leadsto \sqrt[3]{0.5} \cdot \frac{\sqrt[3]{g}}{\color{blue}{\sqrt[3]{a}}} \]
        2. Step-by-step derivation
          1. Applied rewrites98.7%

            \[\leadsto \sqrt[3]{\frac{0.5}{a}} \cdot \color{blue}{\sqrt[3]{g}} \]
          2. Step-by-step derivation
            1. Applied rewrites75.4%

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

            Alternative 4: 76.8% accurate, 1.0× speedup?

            \[\begin{array}{l} \\ \sqrt[3]{\frac{g}{a + a}} \end{array} \]
            (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]
            
            \begin{array}{l}
            
            \\
            \sqrt[3]{\frac{g}{a + a}}
            \end{array}
            
            Derivation
            1. Initial program 75.4%

              \[\sqrt[3]{\frac{g}{2 \cdot a}} \]
            2. Add Preprocessing
            3. 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-+.f6475.4

                \[\leadsto \sqrt[3]{\frac{g}{\color{blue}{a + a}}} \]
            4. Applied rewrites75.4%

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

            Alternative 5: 3.2% accurate, 117.0× speedup?

            \[\begin{array}{l} \\ 0 \end{array} \]
            (FPCore (g a) :precision binary64 0.0)
            double code(double g, double a) {
            	return 0.0;
            }
            
            real(8) function code(g, a)
                real(8), intent (in) :: g
                real(8), intent (in) :: a
                code = 0.0d0
            end function
            
            public static double code(double g, double a) {
            	return 0.0;
            }
            
            def code(g, a):
            	return 0.0
            
            function code(g, a)
            	return 0.0
            end
            
            function tmp = code(g, a)
            	tmp = 0.0;
            end
            
            code[g_, a_] := 0.0
            
            \begin{array}{l}
            
            \\
            0
            \end{array}
            
            Derivation
            1. Initial program 75.4%

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

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

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

                \[\leadsto \sqrt[3]{\frac{g}{\color{blue}{a + a}}} \]
              4. flip3-+N/A

                \[\leadsto \sqrt[3]{\frac{g}{\color{blue}{\frac{{a}^{3} + {a}^{3}}{a \cdot a + \left(a \cdot a - a \cdot a\right)}}}} \]
              5. associate-/r/N/A

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

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

                \[\leadsto \sqrt[3]{\color{blue}{\frac{g}{{a}^{3} + {a}^{3}}} \cdot \left(a \cdot a + \left(a \cdot a - a \cdot a\right)\right)} \]
              8. count-2N/A

                \[\leadsto \sqrt[3]{\frac{g}{\color{blue}{2 \cdot {a}^{3}}} \cdot \left(a \cdot a + \left(a \cdot a - a \cdot a\right)\right)} \]
              9. lower-*.f64N/A

                \[\leadsto \sqrt[3]{\frac{g}{\color{blue}{2 \cdot {a}^{3}}} \cdot \left(a \cdot a + \left(a \cdot a - a \cdot a\right)\right)} \]
              10. lower-pow.f64N/A

                \[\leadsto \sqrt[3]{\frac{g}{2 \cdot \color{blue}{{a}^{3}}} \cdot \left(a \cdot a + \left(a \cdot a - a \cdot a\right)\right)} \]
              11. lower-fma.f64N/A

                \[\leadsto \sqrt[3]{\frac{g}{2 \cdot {a}^{3}} \cdot \color{blue}{\mathsf{fma}\left(a, a, a \cdot a - a \cdot a\right)}} \]
              12. +-inverses24.4

                \[\leadsto \sqrt[3]{\frac{g}{2 \cdot {a}^{3}} \cdot \mathsf{fma}\left(a, a, \color{blue}{0}\right)} \]
            4. Applied rewrites24.4%

              \[\leadsto \sqrt[3]{\color{blue}{\frac{g}{2 \cdot {a}^{3}} \cdot \mathsf{fma}\left(a, a, 0\right)}} \]
            5. Applied rewrites3.2%

              \[\leadsto \sqrt[3]{\color{blue}{0}} \]
            6. Step-by-step derivation
              1. lift-cbrt.f64N/A

                \[\leadsto \color{blue}{\sqrt[3]{0}} \]
              2. pow1/3N/A

                \[\leadsto \color{blue}{{0}^{\frac{1}{3}}} \]
              3. metadata-eval3.2

                \[\leadsto \color{blue}{0} \]
            7. Applied rewrites3.2%

              \[\leadsto \color{blue}{0} \]
            8. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2024333 
            (FPCore (g a)
              :name "2-ancestry mixing, zero discriminant"
              :precision binary64
              (cbrt (/ g (* 2.0 a))))