2-ancestry mixing, negative discriminant

Percentage Accurate: 98.5% → 100.0%
Time: 4.0s
Alternatives: 4
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 4 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: 100.0% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos^{-1} \left(\frac{-g}{h}\right)\\ 2 \cdot \left(\cos \left(-0.3333333333333333 \cdot t\_0\right) \cdot -0.5 - \sin \left(0.3333333333333333 \cdot t\_0\right) \cdot \sin \left(--0.6666666666666666 \cdot \pi\right)\right) \end{array} \end{array} \]
(FPCore (g h)
 :precision binary64
 (let* ((t_0 (acos (/ (- g) h))))
   (*
    2.0
    (-
     (* (cos (* -0.3333333333333333 t_0)) -0.5)
     (*
      (sin (* 0.3333333333333333 t_0))
      (sin (- (* -0.6666666666666666 PI))))))))
double code(double g, double h) {
	double t_0 = acos((-g / h));
	return 2.0 * ((cos((-0.3333333333333333 * t_0)) * -0.5) - (sin((0.3333333333333333 * t_0)) * sin(-(-0.6666666666666666 * ((double) M_PI)))));
}
public static double code(double g, double h) {
	double t_0 = Math.acos((-g / h));
	return 2.0 * ((Math.cos((-0.3333333333333333 * t_0)) * -0.5) - (Math.sin((0.3333333333333333 * t_0)) * Math.sin(-(-0.6666666666666666 * Math.PI))));
}
def code(g, h):
	t_0 = math.acos((-g / h))
	return 2.0 * ((math.cos((-0.3333333333333333 * t_0)) * -0.5) - (math.sin((0.3333333333333333 * t_0)) * math.sin(-(-0.6666666666666666 * math.pi))))
function code(g, h)
	t_0 = acos(Float64(Float64(-g) / h))
	return Float64(2.0 * Float64(Float64(cos(Float64(-0.3333333333333333 * t_0)) * -0.5) - Float64(sin(Float64(0.3333333333333333 * t_0)) * sin(Float64(-Float64(-0.6666666666666666 * pi))))))
end
function tmp = code(g, h)
	t_0 = acos((-g / h));
	tmp = 2.0 * ((cos((-0.3333333333333333 * t_0)) * -0.5) - (sin((0.3333333333333333 * t_0)) * sin(-(-0.6666666666666666 * pi))));
end
code[g_, h_] := Block[{t$95$0 = N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]}, N[(2.0 * N[(N[(N[Cos[N[(-0.3333333333333333 * t$95$0), $MachinePrecision]], $MachinePrecision] * -0.5), $MachinePrecision] - N[(N[Sin[N[(0.3333333333333333 * t$95$0), $MachinePrecision]], $MachinePrecision] * N[Sin[(-N[(-0.6666666666666666 * Pi), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos^{-1} \left(\frac{-g}{h}\right)\\
2 \cdot \left(\cos \left(-0.3333333333333333 \cdot t\_0\right) \cdot -0.5 - \sin \left(0.3333333333333333 \cdot t\_0\right) \cdot \sin \left(--0.6666666666666666 \cdot \pi\right)\right)
\end{array}
\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 rewrites99.9%

    \[\leadsto 2 \cdot \color{blue}{\left(\cos \left(-0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(0.25 - \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{3}}{2}\right) - \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(--0.6666666666666666 \cdot \pi\right)\right)} \]
  3. Step-by-step derivation
    1. lift--.f64N/A

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

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

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

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

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\frac{\sqrt{3}}{2} \cdot \color{blue}{\frac{\sqrt{3}}{2}} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    6. frac-timesN/A

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

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

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\frac{\sqrt{3} \cdot \color{blue}{\sqrt{3}}}{2 \cdot 2} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    9. rem-square-sqrtN/A

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\frac{\color{blue}{3}}{2 \cdot 2} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    10. metadata-evalN/A

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\frac{3}{\color{blue}{4}} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    11. metadata-evalN/A

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\color{blue}{\frac{3}{4}} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\color{blue}{\frac{1}{2}}\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    13. metadata-eval100.0

      \[\leadsto 2 \cdot \left(\cos \left(-0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \color{blue}{-0.5} - \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(--0.6666666666666666 \cdot \pi\right)\right) \]
  4. Applied rewrites100.0%

    \[\leadsto 2 \cdot \color{blue}{\left(\cos \left(-0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot -0.5 - \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(--0.6666666666666666 \cdot \pi\right)\right)} \]
  5. Add Preprocessing

Alternative 2: 100.0% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos^{-1} \left(\frac{-g}{h}\right)\\ \mathsf{fma}\left(\sin \left(t\_0 \cdot -0.3333333333333333\right), \sin \left(0.3333333333333333 \cdot \pi\right) \cdot 2, -1 \cdot \cos \left(0.3333333333333333 \cdot t\_0\right)\right) \end{array} \end{array} \]
(FPCore (g h)
 :precision binary64
 (let* ((t_0 (acos (/ (- g) h))))
   (fma
    (sin (* t_0 -0.3333333333333333))
    (* (sin (* 0.3333333333333333 PI)) 2.0)
    (* -1.0 (cos (* 0.3333333333333333 t_0))))))
double code(double g, double h) {
	double t_0 = acos((-g / h));
	return fma(sin((t_0 * -0.3333333333333333)), (sin((0.3333333333333333 * ((double) M_PI))) * 2.0), (-1.0 * cos((0.3333333333333333 * t_0))));
}
function code(g, h)
	t_0 = acos(Float64(Float64(-g) / h))
	return fma(sin(Float64(t_0 * -0.3333333333333333)), Float64(sin(Float64(0.3333333333333333 * pi)) * 2.0), Float64(-1.0 * cos(Float64(0.3333333333333333 * t_0))))
end
code[g_, h_] := Block[{t$95$0 = N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]}, N[(N[Sin[N[(t$95$0 * -0.3333333333333333), $MachinePrecision]], $MachinePrecision] * N[(N[Sin[N[(0.3333333333333333 * Pi), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision] + N[(-1.0 * N[Cos[N[(0.3333333333333333 * t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos^{-1} \left(\frac{-g}{h}\right)\\
\mathsf{fma}\left(\sin \left(t\_0 \cdot -0.3333333333333333\right), \sin \left(0.3333333333333333 \cdot \pi\right) \cdot 2, -1 \cdot \cos \left(0.3333333333333333 \cdot t\_0\right)\right)
\end{array}
\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 rewrites99.9%

    \[\leadsto 2 \cdot \color{blue}{\left(\cos \left(-0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(0.25 - \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{3}}{2}\right) - \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(--0.6666666666666666 \cdot \pi\right)\right)} \]
  3. Step-by-step derivation
    1. lift--.f64N/A

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

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

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

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

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\frac{\sqrt{3}}{2} \cdot \color{blue}{\frac{\sqrt{3}}{2}} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    6. frac-timesN/A

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

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

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\frac{\sqrt{3} \cdot \color{blue}{\sqrt{3}}}{2 \cdot 2} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    9. rem-square-sqrtN/A

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\frac{\color{blue}{3}}{2 \cdot 2} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    10. metadata-evalN/A

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\frac{3}{\color{blue}{4}} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    11. metadata-evalN/A

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\left(\color{blue}{\frac{3}{4}} - \frac{1}{4}\right)\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto 2 \cdot \left(\cos \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \left(\mathsf{neg}\left(\color{blue}{\frac{1}{2}}\right)\right) - \sin \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(-\frac{-2}{3} \cdot \pi\right)\right) \]
    13. metadata-eval100.0

      \[\leadsto 2 \cdot \left(\cos \left(-0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \color{blue}{-0.5} - \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(--0.6666666666666666 \cdot \pi\right)\right) \]
  4. Applied rewrites100.0%

    \[\leadsto 2 \cdot \color{blue}{\left(\cos \left(-0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot -0.5 - \sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \sin \left(--0.6666666666666666 \cdot \pi\right)\right)} \]
  5. Applied rewrites100.0%

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

Alternative 3: 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-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. lift-/.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto 2 \cdot \cos \left(\color{blue}{\sqrt{\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)}} \cdot \frac{2}{3} + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right)\right)\right) \]
    11. rem-sqrt-square-revN/A

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

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

      \[\leadsto 2 \cdot \cos \left(\left|\mathsf{PI}\left(\right)\right| \cdot \color{blue}{\left|\frac{2}{3}\right|} + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right)\right)\right) \]
    14. fabs-mulN/A

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

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

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

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

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

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

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

      \[\leadsto 2 \cdot \cos \left(\left|\frac{2 \cdot \pi}{3}\right| + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\color{blue}{\frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}}\right)\right)\right)\right)\right) \]
  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

Reproduce

?
herbie shell --seed 2025132 
(FPCore (g h)
  :name "2-ancestry mixing, negative discriminant"
  :precision binary64
  (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))