2-ancestry mixing, negative discriminant

Percentage Accurate: 98.5% → 99.9%
Time: 2.4s
Alternatives: 5
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
double code(double g, double h) {
	return 2.0 * cos((((2.0 * ((double) M_PI)) / 3.0) + (acos((-g / h)) / 3.0)));
}
public static double code(double g, double h) {
	return 2.0 * Math.cos((((2.0 * Math.PI) / 3.0) + (Math.acos((-g / h)) / 3.0)));
}
def code(g, h):
	return 2.0 * math.cos((((2.0 * math.pi) / 3.0) + (math.acos((-g / h)) / 3.0)))
function code(g, h)
	return Float64(2.0 * cos(Float64(Float64(Float64(2.0 * pi) / 3.0) + Float64(acos(Float64(Float64(-g) / h)) / 3.0))))
end
function tmp = code(g, h)
	tmp = 2.0 * cos((((2.0 * pi) / 3.0) + (acos((-g / h)) / 3.0)));
end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(N[(2.0 * Pi), $MachinePrecision] / 3.0), $MachinePrecision] + N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] / 3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)
\end{array}

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: 98.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
double code(double g, double h) {
	return 2.0 * cos((((2.0 * ((double) M_PI)) / 3.0) + (acos((-g / h)) / 3.0)));
}
public static double code(double g, double h) {
	return 2.0 * Math.cos((((2.0 * Math.PI) / 3.0) + (Math.acos((-g / h)) / 3.0)));
}
def code(g, h):
	return 2.0 * math.cos((((2.0 * math.pi) / 3.0) + (math.acos((-g / h)) / 3.0)))
function code(g, h)
	return Float64(2.0 * cos(Float64(Float64(Float64(2.0 * pi) / 3.0) + Float64(acos(Float64(Float64(-g) / h)) / 3.0))))
end
function tmp = code(g, h)
	tmp = 2.0 * cos((((2.0 * pi) / 3.0) + (acos((-g / h)) / 3.0)));
end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(N[(2.0 * Pi), $MachinePrecision] / 3.0), $MachinePrecision] + N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] / 3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)
\end{array}

Alternative 1: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sin \left(\mathsf{fma}\left(-0.3333333333333333, \mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right), \pi \cdot 0.5\right)\right) \cdot 2 \end{array} \]
(FPCore (g h)
 :precision binary64
 (*
  (sin (fma -0.3333333333333333 (fma PI 2.0 (acos (/ (- g) h))) (* PI 0.5)))
  2.0))
double code(double g, double h) {
	return sin(fma(-0.3333333333333333, fma(((double) M_PI), 2.0, acos((-g / h))), (((double) M_PI) * 0.5))) * 2.0;
}
function code(g, h)
	return Float64(sin(fma(-0.3333333333333333, fma(pi, 2.0, acos(Float64(Float64(-g) / h))), Float64(pi * 0.5))) * 2.0)
end
code[g_, h_] := N[(N[Sin[N[(-0.3333333333333333 * N[(Pi * 2.0 + N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}

\\
\sin \left(\mathsf{fma}\left(-0.3333333333333333, \mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right), \pi \cdot 0.5\right)\right) \cdot 2
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Applied rewrites98.5%

    \[\leadsto 2 \cdot \color{blue}{\sin \left(\frac{\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{-3} + \pi \cdot 0.5\right)} \]
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{2 \cdot \sin \left(\frac{\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{-3} + \pi \cdot \frac{1}{2}\right)} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\sin \left(\frac{\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{-3} + \pi \cdot \frac{1}{2}\right) \cdot 2} \]
    3. lower-*.f6498.5

      \[\leadsto \color{blue}{\sin \left(\frac{\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{-3} + \pi \cdot 0.5\right) \cdot 2} \]
  4. Applied rewrites99.9%

    \[\leadsto \color{blue}{\sin \left(\mathsf{fma}\left(-0.3333333333333333, \mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right), \pi \cdot 0.5\right)\right) \cdot 2} \]
  5. Add Preprocessing

Alternative 2: 98.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (/ (fma PI 2.0 (acos (/ (- g) h))) 3.0))))
double code(double g, double h) {
	return 2.0 * cos((fma(((double) M_PI), 2.0, acos((-g / h))) / 3.0));
}
function code(g, h)
	return Float64(2.0 * cos(Float64(fma(pi, 2.0, acos(Float64(Float64(-g) / h))) / 3.0)))
end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(Pi * 2.0 + N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / 3.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \cos \left(\frac{\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{3}\right)
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Step-by-step derivation
    1. lift-+.f64N/A

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

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

      \[\leadsto 2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \color{blue}{\frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}}\right) \]
    4. div-add-revN/A

      \[\leadsto 2 \cdot \cos \color{blue}{\left(\frac{2 \cdot \pi + \cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)} \]
    5. lower-/.f64N/A

      \[\leadsto 2 \cdot \cos \color{blue}{\left(\frac{2 \cdot \pi + \cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)} \]
    6. lift-PI.f64N/A

      \[\leadsto 2 \cdot \cos \left(\frac{2 \cdot \color{blue}{\mathsf{PI}\left(\right)} + \cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    7. lift-*.f64N/A

      \[\leadsto 2 \cdot \cos \left(\frac{\color{blue}{2 \cdot \mathsf{PI}\left(\right)} + \cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    8. *-commutativeN/A

      \[\leadsto 2 \cdot \cos \left(\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot 2} + \cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    9. lower-fma.f64N/A

      \[\leadsto 2 \cdot \cos \left(\frac{\color{blue}{\mathsf{fma}\left(\mathsf{PI}\left(\right), 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}}{3}\right) \]
    10. lift-PI.f6498.5

      \[\leadsto 2 \cdot \cos \left(\frac{\mathsf{fma}\left(\color{blue}{\pi}, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{3}\right) \]
  3. Applied rewrites98.5%

    \[\leadsto 2 \cdot \cos \color{blue}{\left(\frac{\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{3}\right)} \]
  4. Add Preprocessing

Alternative 3: 98.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ 2 \cdot \cos \left(\mathsf{fma}\left(\pi, 0.6666666666666666, 0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (*
  2.0
  (cos (fma PI 0.6666666666666666 (* 0.3333333333333333 (acos (/ (- g) h)))))))
double code(double g, double h) {
	return 2.0 * cos(fma(((double) M_PI), 0.6666666666666666, (0.3333333333333333 * acos((-g / h)))));
}
function code(g, h)
	return Float64(2.0 * cos(fma(pi, 0.6666666666666666, Float64(0.3333333333333333 * acos(Float64(Float64(-g) / h))))))
end
code[g_, h_] := N[(2.0 * N[Cos[N[(Pi * 0.6666666666666666 + N[(0.3333333333333333 * N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \cos \left(\mathsf{fma}\left(\pi, 0.6666666666666666, 0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right)
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Step-by-step derivation
    1. lift-+.f64N/A

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

      \[\leadsto 2 \cdot \cos \left(\color{blue}{\frac{2 \cdot \pi}{3}} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    3. lift-PI.f64N/A

      \[\leadsto 2 \cdot \cos \left(\frac{2 \cdot \color{blue}{\mathsf{PI}\left(\right)}}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    4. lift-*.f64N/A

      \[\leadsto 2 \cdot \cos \left(\frac{\color{blue}{2 \cdot \mathsf{PI}\left(\right)}}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    5. *-commutativeN/A

      \[\leadsto 2 \cdot \cos \left(\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot 2}}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    6. associate-/l*N/A

      \[\leadsto 2 \cdot \cos \left(\color{blue}{\mathsf{PI}\left(\right) \cdot \frac{2}{3}} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    7. metadata-evalN/A

      \[\leadsto 2 \cdot \cos \left(\mathsf{PI}\left(\right) \cdot \color{blue}{\frac{2}{3}} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    8. lower-fma.f64N/A

      \[\leadsto 2 \cdot \cos \color{blue}{\left(\mathsf{fma}\left(\mathsf{PI}\left(\right), \frac{2}{3}, \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)} \]
    9. lift-PI.f6498.5

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\color{blue}{\pi}, 0.6666666666666666, \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right) \]
    10. lift-/.f64N/A

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\pi, \frac{2}{3}, \color{blue}{\frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}}\right)\right) \]
    11. mult-flipN/A

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\pi, \frac{2}{3}, \color{blue}{\cos^{-1} \left(\frac{-g}{h}\right) \cdot \frac{1}{3}}\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\pi, \frac{2}{3}, \cos^{-1} \left(\frac{-g}{h}\right) \cdot \color{blue}{\frac{1}{3}}\right)\right) \]
    13. *-commutativeN/A

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\pi, \frac{2}{3}, \color{blue}{\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)}\right)\right) \]
    14. lower-*.f6498.5

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\pi, 0.6666666666666666, \color{blue}{0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)}\right)\right) \]
  3. Applied rewrites98.5%

    \[\leadsto 2 \cdot \cos \color{blue}{\left(\mathsf{fma}\left(\pi, 0.6666666666666666, 0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right)} \]
  4. Add Preprocessing

Alternative 4: 97.6% accurate, 1.1× speedup?

\[\begin{array}{l} \\ 2 \cdot \sin \left(\mathsf{fma}\left(\pi, 1.1666666666666667, \cos^{-1} \left(\frac{-g}{h}\right) \cdot 0.3333333333333333\right)\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (*
  2.0
  (sin (fma PI 1.1666666666666667 (* (acos (/ (- g) h)) 0.3333333333333333)))))
double code(double g, double h) {
	return 2.0 * sin(fma(((double) M_PI), 1.1666666666666667, (acos((-g / h)) * 0.3333333333333333)));
}
function code(g, h)
	return Float64(2.0 * sin(fma(pi, 1.1666666666666667, Float64(acos(Float64(Float64(-g) / h)) * 0.3333333333333333))))
end
code[g_, h_] := N[(2.0 * N[Sin[N[(Pi * 1.1666666666666667 + N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \sin \left(\mathsf{fma}\left(\pi, 1.1666666666666667, \cos^{-1} \left(\frac{-g}{h}\right) \cdot 0.3333333333333333\right)\right)
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Applied rewrites97.6%

    \[\leadsto 2 \cdot \color{blue}{\sin \left(\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{-g}{h}\right), \mathsf{fma}\left(0.6666666666666666, \pi, \pi \cdot 0.5\right)\right)\right)} \]
  3. Step-by-step derivation
    1. lift-fma.f64N/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \mathsf{fma}\left(\frac{2}{3}, \pi, \pi \cdot \frac{1}{2}\right)\right)} \]
    2. lift-*.f64N/A

      \[\leadsto 2 \cdot \sin \left(\color{blue}{\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)} + \mathsf{fma}\left(\frac{2}{3}, \pi, \pi \cdot \frac{1}{2}\right)\right) \]
    3. +-commutativeN/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\mathsf{fma}\left(\frac{2}{3}, \pi, \pi \cdot \frac{1}{2}\right) + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)} \]
    4. lift-PI.f64N/A

      \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\frac{2}{3}, \color{blue}{\mathsf{PI}\left(\right)}, \pi \cdot \frac{1}{2}\right) + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
    5. lift-fma.f64N/A

      \[\leadsto 2 \cdot \sin \left(\color{blue}{\left(\frac{2}{3} \cdot \mathsf{PI}\left(\right) + \pi \cdot \frac{1}{2}\right)} + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
    6. lift-PI.f64N/A

      \[\leadsto 2 \cdot \sin \left(\left(\frac{2}{3} \cdot \mathsf{PI}\left(\right) + \color{blue}{\mathsf{PI}\left(\right)} \cdot \frac{1}{2}\right) + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
    7. lift-*.f64N/A

      \[\leadsto 2 \cdot \sin \left(\left(\frac{2}{3} \cdot \mathsf{PI}\left(\right) + \color{blue}{\mathsf{PI}\left(\right) \cdot \frac{1}{2}}\right) + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
    8. *-commutativeN/A

      \[\leadsto 2 \cdot \sin \left(\left(\frac{2}{3} \cdot \mathsf{PI}\left(\right) + \color{blue}{\frac{1}{2} \cdot \mathsf{PI}\left(\right)}\right) + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
    9. +-commutativeN/A

      \[\leadsto 2 \cdot \sin \left(\color{blue}{\left(\frac{1}{2} \cdot \mathsf{PI}\left(\right) + \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right)} + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
    10. distribute-rgt-outN/A

      \[\leadsto 2 \cdot \sin \left(\color{blue}{\mathsf{PI}\left(\right) \cdot \left(\frac{1}{2} + \frac{2}{3}\right)} + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
    11. lower-fma.f64N/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\mathsf{fma}\left(\mathsf{PI}\left(\right), \frac{1}{2} + \frac{2}{3}, \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right)} \]
    12. lift-PI.f64N/A

      \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\color{blue}{\pi}, \frac{1}{2} + \frac{2}{3}, \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right) \]
    13. metadata-eval97.6

      \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\pi, \color{blue}{1.1666666666666667}, 0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right) \]
    14. lift-*.f64N/A

      \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\pi, \frac{7}{6}, \color{blue}{\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)}\right)\right) \]
    15. *-commutativeN/A

      \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\pi, \frac{7}{6}, \color{blue}{\cos^{-1} \left(\frac{-g}{h}\right) \cdot \frac{1}{3}}\right)\right) \]
    16. lower-*.f6497.6

      \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\pi, 1.1666666666666667, \color{blue}{\cos^{-1} \left(\frac{-g}{h}\right) \cdot 0.3333333333333333}\right)\right) \]
  4. Applied rewrites97.6%

    \[\leadsto 2 \cdot \sin \color{blue}{\left(\mathsf{fma}\left(\pi, 1.1666666666666667, \cos^{-1} \left(\frac{-g}{h}\right) \cdot 0.3333333333333333\right)\right)} \]
  5. Add Preprocessing

Alternative 5: 97.6% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \sin \left(\mathsf{fma}\left(\cos^{-1} \left(\frac{-g}{h}\right), 0.3333333333333333, \pi \cdot 1.1666666666666667\right)\right) \cdot 2 \end{array} \]
(FPCore (g h)
 :precision binary64
 (*
  (sin (fma (acos (/ (- g) h)) 0.3333333333333333 (* PI 1.1666666666666667)))
  2.0))
double code(double g, double h) {
	return sin(fma(acos((-g / h)), 0.3333333333333333, (((double) M_PI) * 1.1666666666666667))) * 2.0;
}
function code(g, h)
	return Float64(sin(fma(acos(Float64(Float64(-g) / h)), 0.3333333333333333, Float64(pi * 1.1666666666666667))) * 2.0)
end
code[g_, h_] := N[(N[Sin[N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] * 0.3333333333333333 + N[(Pi * 1.1666666666666667), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}

\\
\sin \left(\mathsf{fma}\left(\cos^{-1} \left(\frac{-g}{h}\right), 0.3333333333333333, \pi \cdot 1.1666666666666667\right)\right) \cdot 2
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Applied rewrites97.6%

    \[\leadsto 2 \cdot \color{blue}{\sin \left(\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{-g}{h}\right), \mathsf{fma}\left(0.6666666666666666, \pi, \pi \cdot 0.5\right)\right)\right)} \]
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{2 \cdot \sin \left(\mathsf{fma}\left(\frac{1}{3}, \cos^{-1} \left(\frac{-g}{h}\right), \mathsf{fma}\left(\frac{2}{3}, \pi, \pi \cdot \frac{1}{2}\right)\right)\right)} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\sin \left(\mathsf{fma}\left(\frac{1}{3}, \cos^{-1} \left(\frac{-g}{h}\right), \mathsf{fma}\left(\frac{2}{3}, \pi, \pi \cdot \frac{1}{2}\right)\right)\right) \cdot 2} \]
    3. lower-*.f6497.6

      \[\leadsto \color{blue}{\sin \left(\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{-g}{h}\right), \mathsf{fma}\left(0.6666666666666666, \pi, \pi \cdot 0.5\right)\right)\right) \cdot 2} \]
  4. Applied rewrites97.6%

    \[\leadsto \color{blue}{\sin \left(\mathsf{fma}\left(\cos^{-1} \left(\frac{-g}{h}\right), 0.3333333333333333, \pi \cdot 1.1666666666666667\right)\right) \cdot 2} \]
  5. Add Preprocessing

Reproduce

?
herbie shell --seed 2025120 
(FPCore (g h)
  :name "2-ancestry mixing, negative discriminant"
  :precision binary64
  (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))