2-ancestry mixing, negative discriminant

Percentage Accurate: 98.4% → 100.0%
Time: 12.3s
Alternatives: 6
Speedup: 1.0×

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}

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 6 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: 98.4% 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: 100.0% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\\ \mathsf{fma}\left(\sqrt{3} \cdot -0.8125, \sin t\_0, -0.8125 \cdot \cos t\_0\right) \cdot 1.2307692307692308 \end{array} \end{array} \]
(FPCore (g h)
 :precision binary64
 (let* ((t_0 (* 0.3333333333333333 (acos (/ g (- h))))))
   (*
    (fma (* (sqrt 3.0) -0.8125) (sin t_0) (* -0.8125 (cos t_0)))
    1.2307692307692308)))
double code(double g, double h) {
	double t_0 = 0.3333333333333333 * acos((g / -h));
	return fma((sqrt(3.0) * -0.8125), sin(t_0), (-0.8125 * cos(t_0))) * 1.2307692307692308;
}
function code(g, h)
	t_0 = Float64(0.3333333333333333 * acos(Float64(g / Float64(-h))))
	return Float64(fma(Float64(sqrt(3.0) * -0.8125), sin(t_0), Float64(-0.8125 * cos(t_0))) * 1.2307692307692308)
end
code[g_, h_] := Block[{t$95$0 = N[(0.3333333333333333 * N[ArcCos[N[(g / (-h)), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[Sqrt[3.0], $MachinePrecision] * -0.8125), $MachinePrecision] * N[Sin[t$95$0], $MachinePrecision] + N[(-0.8125 * N[Cos[t$95$0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 1.2307692307692308), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\\
\mathsf{fma}\left(\sqrt{3} \cdot -0.8125, \sin t\_0, -0.8125 \cdot \cos t\_0\right) \cdot 1.2307692307692308
\end{array}
\end{array}
Derivation
  1. Initial program 98.4%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Add Preprocessing
  3. Applied rewrites98.4%

    \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(0.25 - \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{3}}{2}, \cos \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right), \sin \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot \left(-2 \cdot \left(\frac{\sqrt{3}}{2} \cdot 0.5\right)\right)\right)} \]
  4. Applied rewrites99.9%

    \[\leadsto 2 \cdot \color{blue}{\frac{\mathsf{fma}\left(\cos \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot -0.40625, 2, 0.8125 \cdot \left(\sin \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot \left(\left(\sqrt{3} \cdot -0.5\right) \cdot 2\right)\right)\right)}{1.625}} \]
  5. Step-by-step derivation
    1. lift-fma.f64N/A

      \[\leadsto 2 \cdot \frac{\color{blue}{\left(\cos \left(\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right) \cdot \frac{-13}{32}\right) \cdot 2 + \frac{13}{16} \cdot \left(\sin \left(\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right) \cdot \left(\left(\sqrt{3} \cdot \frac{-1}{2}\right) \cdot 2\right)\right)}}{\frac{13}{8}} \]
    2. +-commutativeN/A

      \[\leadsto 2 \cdot \frac{\color{blue}{\frac{13}{16} \cdot \left(\sin \left(\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right) \cdot \left(\left(\sqrt{3} \cdot \frac{-1}{2}\right) \cdot 2\right)\right) + \left(\cos \left(\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right) \cdot \frac{-13}{32}\right) \cdot 2}}{\frac{13}{8}} \]
  6. Applied rewrites99.9%

    \[\leadsto 2 \cdot \frac{\color{blue}{\mathsf{fma}\left(0.8125 \cdot \left(-\sqrt{3}\right), \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right), \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right) \cdot -0.8125\right)}}{1.625} \]
  7. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{2 \cdot \frac{\mathsf{fma}\left(\frac{13}{16} \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right), \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right), \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right) \cdot \frac{-13}{16}\right)}{\frac{13}{8}}} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\frac{13}{16} \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right), \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right), \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right) \cdot \frac{-13}{16}\right)}{\frac{13}{8}} \cdot 2} \]
    3. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\frac{13}{16} \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right), \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right), \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right) \cdot \frac{-13}{16}\right)}{\frac{13}{8}}} \cdot 2 \]
    4. div-invN/A

      \[\leadsto \color{blue}{\left(\mathsf{fma}\left(\frac{13}{16} \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right), \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right), \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right) \cdot \frac{-13}{16}\right) \cdot \frac{1}{\frac{13}{8}}\right)} \cdot 2 \]
    5. associate-*l*N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{13}{16} \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right), \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right), \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right) \cdot \frac{-13}{16}\right) \cdot \left(\frac{1}{\frac{13}{8}} \cdot 2\right)} \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(\frac{13}{16} \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right), \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right), \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right) \cdot \frac{-13}{16}\right) \cdot \left(\color{blue}{\frac{8}{13}} \cdot 2\right) \]
    7. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(\frac{13}{16} \cdot \left(\mathsf{neg}\left(\sqrt{3}\right)\right), \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right), \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right)\right) \cdot \frac{-13}{16}\right) \cdot \color{blue}{\frac{16}{13}} \]
    8. lower-*.f64100.0

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.8125 \cdot \left(-\sqrt{3}\right), \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right), \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right) \cdot -0.8125\right) \cdot 1.2307692307692308} \]
  8. Applied rewrites100.0%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt{3} \cdot -0.8125, \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right), \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right) \cdot -0.8125\right) \cdot 1.2307692307692308} \]
  9. Final simplification100.0%

    \[\leadsto \mathsf{fma}\left(\sqrt{3} \cdot -0.8125, \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right), -0.8125 \cdot \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right)\right) \cdot 1.2307692307692308 \]
  10. Add Preprocessing

Alternative 2: 100.0% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\\ 1.2307692307692308 \cdot \left(-0.8125 \cdot \mathsf{fma}\left(\sin t\_0, \sqrt{3}, \cos t\_0\right)\right) \end{array} \end{array} \]
(FPCore (g h)
 :precision binary64
 (let* ((t_0 (* 0.3333333333333333 (acos (/ g (- h))))))
   (* 1.2307692307692308 (* -0.8125 (fma (sin t_0) (sqrt 3.0) (cos t_0))))))
double code(double g, double h) {
	double t_0 = 0.3333333333333333 * acos((g / -h));
	return 1.2307692307692308 * (-0.8125 * fma(sin(t_0), sqrt(3.0), cos(t_0)));
}
function code(g, h)
	t_0 = Float64(0.3333333333333333 * acos(Float64(g / Float64(-h))))
	return Float64(1.2307692307692308 * Float64(-0.8125 * fma(sin(t_0), sqrt(3.0), cos(t_0))))
end
code[g_, h_] := Block[{t$95$0 = N[(0.3333333333333333 * N[ArcCos[N[(g / (-h)), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(1.2307692307692308 * N[(-0.8125 * N[(N[Sin[t$95$0], $MachinePrecision] * N[Sqrt[3.0], $MachinePrecision] + N[Cos[t$95$0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\\
1.2307692307692308 \cdot \left(-0.8125 \cdot \mathsf{fma}\left(\sin t\_0, \sqrt{3}, \cos t\_0\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 98.4%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Add Preprocessing
  3. Applied rewrites98.4%

    \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(0.25 - \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{3}}{2}, \cos \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right), \sin \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot \left(-2 \cdot \left(\frac{\sqrt{3}}{2} \cdot 0.5\right)\right)\right)} \]
  4. Applied rewrites100.0%

    \[\leadsto 2 \cdot \color{blue}{\frac{\mathsf{fma}\left(\cos \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot -0.40625, 2, 0.8125 \cdot \left(\sin \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot \left(\left(\sqrt{3} \cdot -0.5\right) \cdot 2\right)\right)\right)}{1.625}} \]
  5. Applied rewrites100.0%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\cos \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right), -0.8125, \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right) \cdot \left(\left(-\sqrt{3}\right) \cdot 0.8125\right)\right) \cdot 1.2307692307692308} \]
  6. Taylor expanded in g around 0

    \[\leadsto \color{blue}{\left(\frac{-13}{16} \cdot \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) + \frac{-13}{16} \cdot \left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \sqrt{3}\right)\right)} \cdot \frac{16}{13} \]
  7. Step-by-step derivation
    1. distribute-lft-outN/A

      \[\leadsto \color{blue}{\left(\frac{-13}{16} \cdot \left(\cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) + \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \sqrt{3}\right)\right)} \cdot \frac{16}{13} \]
    2. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(\frac{-13}{16} \cdot \left(\cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) + \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \sqrt{3}\right)\right)} \cdot \frac{16}{13} \]
    3. +-commutativeN/A

      \[\leadsto \left(\frac{-13}{16} \cdot \color{blue}{\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \sqrt{3} + \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)}\right) \cdot \frac{16}{13} \]
    4. lower-fma.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \color{blue}{\mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right), \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)}\right) \cdot \frac{16}{13} \]
    5. lower-sin.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\color{blue}{\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)}, \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)\right) \cdot \frac{16}{13} \]
    6. lower-*.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \color{blue}{\left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)}, \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)\right) \cdot \frac{16}{13} \]
    7. lower-acos.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \color{blue}{\cos^{-1} \left(-1 \cdot \frac{g}{h}\right)}\right), \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)\right) \cdot \frac{16}{13} \]
    8. mul-1-negN/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \color{blue}{\left(\mathsf{neg}\left(\frac{g}{h}\right)\right)}\right), \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)\right) \cdot \frac{16}{13} \]
    9. lower-neg.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \color{blue}{\left(\mathsf{neg}\left(\frac{g}{h}\right)\right)}\right), \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)\right) \cdot \frac{16}{13} \]
    10. lower-/.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\color{blue}{\frac{g}{h}}\right)\right)\right), \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)\right) \cdot \frac{16}{13} \]
    11. lower-sqrt.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right), \color{blue}{\sqrt{3}}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right)\right) \cdot \frac{16}{13} \]
    12. lower-cos.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right), \sqrt{3}, \color{blue}{\cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)}\right)\right) \cdot \frac{16}{13} \]
    13. lower-*.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right), \sqrt{3}, \cos \color{blue}{\left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)}\right)\right) \cdot \frac{16}{13} \]
    14. lower-acos.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right), \sqrt{3}, \cos \left(\frac{1}{3} \cdot \color{blue}{\cos^{-1} \left(-1 \cdot \frac{g}{h}\right)}\right)\right)\right) \cdot \frac{16}{13} \]
    15. mul-1-negN/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right), \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \color{blue}{\left(\mathsf{neg}\left(\frac{g}{h}\right)\right)}\right)\right)\right) \cdot \frac{16}{13} \]
    16. lower-neg.f64N/A

      \[\leadsto \left(\frac{-13}{16} \cdot \mathsf{fma}\left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right), \sqrt{3}, \cos \left(\frac{1}{3} \cdot \cos^{-1} \color{blue}{\left(\mathsf{neg}\left(\frac{g}{h}\right)\right)}\right)\right)\right) \cdot \frac{16}{13} \]
    17. lower-/.f64100.0

      \[\leadsto \left(-0.8125 \cdot \mathsf{fma}\left(\sin \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right), \sqrt{3}, \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(-\color{blue}{\frac{g}{h}}\right)\right)\right)\right) \cdot 1.2307692307692308 \]
  8. Applied rewrites100.0%

    \[\leadsto \color{blue}{\left(-0.8125 \cdot \mathsf{fma}\left(\sin \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right), \sqrt{3}, \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(-\frac{g}{h}\right)\right)\right)\right)} \cdot 1.2307692307692308 \]
  9. Final simplification100.0%

    \[\leadsto 1.2307692307692308 \cdot \left(-0.8125 \cdot \mathsf{fma}\left(\sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right), \sqrt{3}, \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right)\right)\right) \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2024226 
(FPCore (g h)
  :name "2-ancestry mixing, negative discriminant"
  :precision binary64
  (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))