2-ancestry mixing, negative discriminant

Percentage Accurate: 98.5% → 100.0%
Time: 11.1s
Alternatives: 3
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}

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 3 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, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \pi \cdot \left(\pi \cdot 0.4444444444444444\right)\\ t_1 := \cos^{-1} \left(\frac{g}{-h}\right)\\ t_2 := {t\_1}^{2}\\ t_3 := \mathsf{fma}\left(0.3333333333333333, t\_1, \pi \cdot -0.6666666666666666\right)\\ 2 \cdot \mathsf{fma}\left(\sin \left(\frac{t\_0}{t\_3}\right), \sin \left(t\_2 \cdot \frac{0.1111111111111111}{t\_3}\right), \left(\cos \left(\mathsf{fma}\left(0.3333333333333333, t\_1, \pi \cdot 0.6666666666666666\right)\right) + \cos \left(\frac{1}{t\_3} \cdot \mathsf{fma}\left(t\_2, 0.1111111111111111, t\_0\right)\right)\right) \cdot 0.5\right) \end{array} \end{array} \]
(FPCore (g h)
 :precision binary64
 (let* ((t_0 (* PI (* PI 0.4444444444444444)))
        (t_1 (acos (/ g (- h))))
        (t_2 (pow t_1 2.0))
        (t_3 (fma 0.3333333333333333 t_1 (* PI -0.6666666666666666))))
   (*
    2.0
    (fma
     (sin (/ t_0 t_3))
     (sin (* t_2 (/ 0.1111111111111111 t_3)))
     (*
      (+
       (cos (fma 0.3333333333333333 t_1 (* PI 0.6666666666666666)))
       (cos (* (/ 1.0 t_3) (fma t_2 0.1111111111111111 t_0))))
      0.5)))))
double code(double g, double h) {
	double t_0 = ((double) M_PI) * (((double) M_PI) * 0.4444444444444444);
	double t_1 = acos((g / -h));
	double t_2 = pow(t_1, 2.0);
	double t_3 = fma(0.3333333333333333, t_1, (((double) M_PI) * -0.6666666666666666));
	return 2.0 * fma(sin((t_0 / t_3)), sin((t_2 * (0.1111111111111111 / t_3))), ((cos(fma(0.3333333333333333, t_1, (((double) M_PI) * 0.6666666666666666))) + cos(((1.0 / t_3) * fma(t_2, 0.1111111111111111, t_0)))) * 0.5));
}
function code(g, h)
	t_0 = Float64(pi * Float64(pi * 0.4444444444444444))
	t_1 = acos(Float64(g / Float64(-h)))
	t_2 = t_1 ^ 2.0
	t_3 = fma(0.3333333333333333, t_1, Float64(pi * -0.6666666666666666))
	return Float64(2.0 * fma(sin(Float64(t_0 / t_3)), sin(Float64(t_2 * Float64(0.1111111111111111 / t_3))), Float64(Float64(cos(fma(0.3333333333333333, t_1, Float64(pi * 0.6666666666666666))) + cos(Float64(Float64(1.0 / t_3) * fma(t_2, 0.1111111111111111, t_0)))) * 0.5)))
end
code[g_, h_] := Block[{t$95$0 = N[(Pi * N[(Pi * 0.4444444444444444), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[ArcCos[N[(g / (-h)), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[Power[t$95$1, 2.0], $MachinePrecision]}, Block[{t$95$3 = N[(0.3333333333333333 * t$95$1 + N[(Pi * -0.6666666666666666), $MachinePrecision]), $MachinePrecision]}, N[(2.0 * N[(N[Sin[N[(t$95$0 / t$95$3), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(t$95$2 * N[(0.1111111111111111 / t$95$3), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + N[(N[(N[Cos[N[(0.3333333333333333 * t$95$1 + N[(Pi * 0.6666666666666666), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + N[Cos[N[(N[(1.0 / t$95$3), $MachinePrecision] * N[(t$95$2 * 0.1111111111111111 + t$95$0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \pi \cdot \left(\pi \cdot 0.4444444444444444\right)\\
t_1 := \cos^{-1} \left(\frac{g}{-h}\right)\\
t_2 := {t\_1}^{2}\\
t_3 := \mathsf{fma}\left(0.3333333333333333, t\_1, \pi \cdot -0.6666666666666666\right)\\
2 \cdot \mathsf{fma}\left(\sin \left(\frac{t\_0}{t\_3}\right), \sin \left(t\_2 \cdot \frac{0.1111111111111111}{t\_3}\right), \left(\cos \left(\mathsf{fma}\left(0.3333333333333333, t\_1, \pi \cdot 0.6666666666666666\right)\right) + \cos \left(\frac{1}{t\_3} \cdot \mathsf{fma}\left(t\_2, 0.1111111111111111, t\_0\right)\right)\right) \cdot 0.5\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. Add Preprocessing
  3. Step-by-step derivation
    1. lift-+.f64N/A

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

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

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

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

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

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

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

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\mathsf{PI}\left(\right), 2 \cdot \color{blue}{\frac{1}{3}}, \frac{\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right)}{3}\right)\right) \]
    9. metadata-eval98.5

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

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

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

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

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

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

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\mathsf{PI}\left(\right), \frac{2}{3}, \cos^{-1} \left(\frac{\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(g\right)\right)}\right)}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right)\right) \]
    16. remove-double-negN/A

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

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

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\mathsf{PI}\left(\right), \frac{2}{3}, \cos^{-1} \left(\frac{g}{\color{blue}{\mathsf{neg}\left(h\right)}}\right) \cdot \frac{1}{3}\right)\right) \]
    19. metadata-eval98.5

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

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

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

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

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

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

      \[\leadsto 2 \cdot \cos \color{blue}{\left(\frac{\left(\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right) \cdot \left(\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right) - \left(\mathsf{PI}\left(\right) \cdot \frac{2}{3}\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \frac{2}{3}\right)}{\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3} - \mathsf{PI}\left(\right) \cdot \frac{2}{3}}\right)} \]
    6. unpow2N/A

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

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

      \[\leadsto 2 \cdot \cos \color{blue}{\left(\frac{{\left(\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right)}^{2}}{\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3} - \mathsf{PI}\left(\right) \cdot \frac{2}{3}} - \frac{\left(\mathsf{PI}\left(\right) \cdot \frac{2}{3}\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \frac{2}{3}\right)}{\cos^{-1} \left(\frac{g}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3} - \mathsf{PI}\left(\right) \cdot \frac{2}{3}}\right)} \]
  6. Applied rewrites98.4%

    \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(\cos \left(\frac{{\left(\cos^{-1} \left(-\frac{g}{h}\right) \cdot 0.3333333333333333\right)}^{2}}{\mathsf{fma}\left(\cos^{-1} \left(-\frac{g}{h}\right), 0.3333333333333333, -0.6666666666666666 \cdot \pi\right)}\right), \cos \left(\frac{\pi \cdot \left(\pi \cdot 0.4444444444444444\right)}{\mathsf{fma}\left(\cos^{-1} \left(-\frac{g}{h}\right), 0.3333333333333333, -0.6666666666666666 \cdot \pi\right)}\right), \sin \left(\frac{{\left(\cos^{-1} \left(-\frac{g}{h}\right) \cdot 0.3333333333333333\right)}^{2}}{\mathsf{fma}\left(\cos^{-1} \left(-\frac{g}{h}\right), 0.3333333333333333, -0.6666666666666666 \cdot \pi\right)}\right) \cdot \sin \left(\frac{\pi \cdot \left(\pi \cdot 0.4444444444444444\right)}{\mathsf{fma}\left(\cos^{-1} \left(-\frac{g}{h}\right), 0.3333333333333333, -0.6666666666666666 \cdot \pi\right)}\right)\right)} \]
  7. Step-by-step derivation
    1. lift-fma.f64N/A

      \[\leadsto 2 \cdot \color{blue}{\left(\cos \left(\frac{{\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right) \cdot \frac{1}{3}\right)}^{2}}{\mathsf{fma}\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right), \frac{1}{3}, \frac{-2}{3} \cdot \mathsf{PI}\left(\right)\right)}\right) \cdot \cos \left(\frac{\mathsf{PI}\left(\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \frac{4}{9}\right)}{\mathsf{fma}\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right), \frac{1}{3}, \frac{-2}{3} \cdot \mathsf{PI}\left(\right)\right)}\right) + \sin \left(\frac{{\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right) \cdot \frac{1}{3}\right)}^{2}}{\mathsf{fma}\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right), \frac{1}{3}, \frac{-2}{3} \cdot \mathsf{PI}\left(\right)\right)}\right) \cdot \sin \left(\frac{\mathsf{PI}\left(\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \frac{4}{9}\right)}{\mathsf{fma}\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right), \frac{1}{3}, \frac{-2}{3} \cdot \mathsf{PI}\left(\right)\right)}\right)\right)} \]
    2. +-commutativeN/A

      \[\leadsto 2 \cdot \color{blue}{\left(\sin \left(\frac{{\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right) \cdot \frac{1}{3}\right)}^{2}}{\mathsf{fma}\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right), \frac{1}{3}, \frac{-2}{3} \cdot \mathsf{PI}\left(\right)\right)}\right) \cdot \sin \left(\frac{\mathsf{PI}\left(\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \frac{4}{9}\right)}{\mathsf{fma}\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right), \frac{1}{3}, \frac{-2}{3} \cdot \mathsf{PI}\left(\right)\right)}\right) + \cos \left(\frac{{\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right) \cdot \frac{1}{3}\right)}^{2}}{\mathsf{fma}\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right), \frac{1}{3}, \frac{-2}{3} \cdot \mathsf{PI}\left(\right)\right)}\right) \cdot \cos \left(\frac{\mathsf{PI}\left(\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \frac{4}{9}\right)}{\mathsf{fma}\left(\cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right), \frac{1}{3}, \frac{-2}{3} \cdot \mathsf{PI}\left(\right)\right)}\right)\right)} \]
  8. Applied rewrites100.0%

    \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(\sin \left(\frac{\pi \cdot \left(\pi \cdot 0.4444444444444444\right)}{\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{g}{-h}\right), \pi \cdot -0.6666666666666666\right)}\right), \sin \left({\cos^{-1} \left(\frac{g}{-h}\right)}^{2} \cdot \frac{0.1111111111111111}{\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{g}{-h}\right), \pi \cdot -0.6666666666666666\right)}\right), \left(\cos \left(\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{g}{-h}\right), 0.6666666666666666 \cdot \pi\right)\right) + \cos \left(\frac{1}{\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{g}{-h}\right), \pi \cdot -0.6666666666666666\right)} \cdot \mathsf{fma}\left({\cos^{-1} \left(\frac{g}{-h}\right)}^{2}, 0.1111111111111111, \pi \cdot \left(\pi \cdot 0.4444444444444444\right)\right)\right)\right) \cdot 0.5\right)} \]
  9. Final simplification100.0%

    \[\leadsto 2 \cdot \mathsf{fma}\left(\sin \left(\frac{\pi \cdot \left(\pi \cdot 0.4444444444444444\right)}{\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{g}{-h}\right), \pi \cdot -0.6666666666666666\right)}\right), \sin \left({\cos^{-1} \left(\frac{g}{-h}\right)}^{2} \cdot \frac{0.1111111111111111}{\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{g}{-h}\right), \pi \cdot -0.6666666666666666\right)}\right), \left(\cos \left(\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{g}{-h}\right), \pi \cdot 0.6666666666666666\right)\right) + \cos \left(\frac{1}{\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{g}{-h}\right), \pi \cdot -0.6666666666666666\right)} \cdot \mathsf{fma}\left({\cos^{-1} \left(\frac{g}{-h}\right)}^{2}, 0.1111111111111111, \pi \cdot \left(\pi \cdot 0.4444444444444444\right)\right)\right)\right) \cdot 0.5\right) \]
  10. Add Preprocessing

Alternative 2: 100.0% accurate, 0.5× speedup?

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

\\
\begin{array}{l}
t_0 := 0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\\
-\mathsf{fma}\left(\sin t\_0, \sqrt{3}, \cos t\_0\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. Add Preprocessing
  3. Step-by-step derivation
    1. lift-cos.f64N/A

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

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

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

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

      \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(\cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3}\right), \cos \left(\frac{\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right)}{3}\right), \mathsf{neg}\left(\sin \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3}\right) \cdot \sin \left(\frac{\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right)}{3}\right)\right)\right)} \]
  4. Applied rewrites98.4%

    \[\leadsto 2 \cdot \color{blue}{\mathsf{fma}\left(0.25 - \frac{\sqrt{3}}{2} \cdot \frac{\sqrt{3}}{2}, \cos \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right), \sin \left(\cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right) \cdot \left(-2 \cdot \left(\frac{\sqrt{3}}{2} \cdot 0.5\right)\right)\right)} \]
  5. Taylor expanded in g around 0

    \[\leadsto \color{blue}{2 \cdot \left(\frac{-1}{2} \cdot \left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \sqrt{3}\right) + \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \left(\frac{1}{4} - \frac{1}{4} \cdot {\left(\sqrt{3}\right)}^{2}\right)\right)} \]
  6. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto 2 \cdot \color{blue}{\left(\cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \left(\frac{1}{4} - \frac{1}{4} \cdot {\left(\sqrt{3}\right)}^{2}\right) + \frac{-1}{2} \cdot \left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \sqrt{3}\right)\right)} \]
    2. distribute-lft-inN/A

      \[\leadsto \color{blue}{2 \cdot \left(\cos \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \left(\frac{1}{4} - \frac{1}{4} \cdot {\left(\sqrt{3}\right)}^{2}\right)\right) + 2 \cdot \left(\frac{-1}{2} \cdot \left(\sin \left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \cdot \sqrt{3}\right)\right)} \]
  7. Applied rewrites100.0%

    \[\leadsto \color{blue}{-\mathsf{fma}\left(\sin \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right), \sqrt{3}, \cos \left(0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right)\right)} \]
  8. 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(g / Float64(-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. Add Preprocessing
  3. Step-by-step derivation
    1. lift-+.f64N/A

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

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

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

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

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

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

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

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\mathsf{PI}\left(\right), 2 \cdot \color{blue}{\frac{1}{3}}, \frac{\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right)}{3}\right)\right) \]
    9. metadata-eval98.5

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

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

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

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

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

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

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\mathsf{PI}\left(\right), \frac{2}{3}, \cos^{-1} \left(\frac{\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(g\right)\right)}\right)}{\mathsf{neg}\left(h\right)}\right) \cdot \frac{1}{3}\right)\right) \]
    16. remove-double-negN/A

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

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

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\mathsf{PI}\left(\right), \frac{2}{3}, \cos^{-1} \left(\frac{g}{\color{blue}{\mathsf{neg}\left(h\right)}}\right) \cdot \frac{1}{3}\right)\right) \]
    19. metadata-eval98.5

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

    \[\leadsto 2 \cdot \cos \color{blue}{\left(\mathsf{fma}\left(\pi, 0.6666666666666666, \cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\right)\right)} \]
  5. Final simplification98.5%

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

Reproduce

?
herbie shell --seed 2024231 
(FPCore (g h)
  :name "2-ancestry mixing, negative discriminant"
  :precision binary64
  (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))