
(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:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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}
(FPCore (g h)
:precision binary64
(let* ((t_0 (/ (sqrt 3.0) 2.0))
(t_1 (* (acos (/ g (- h))) 0.3333333333333333))
(t_2 (* (* t_0 0.5) (sin t_1)))
(t_3 (* (- 0.25 (* t_0 t_0)) (cos t_1))))
(*
2.0
(/
(- (pow t_3 3.0) (pow (* 0.75 (- 0.5 (* 0.5 (cos (* 2.0 t_1))))) 1.5))
(+ (pow t_3 2.0) (* (* 2.0 t_2) (fma 2.0 t_2 t_3)))))))
double code(double g, double h) {
double t_0 = sqrt(3.0) / 2.0;
double t_1 = acos((g / -h)) * 0.3333333333333333;
double t_2 = (t_0 * 0.5) * sin(t_1);
double t_3 = (0.25 - (t_0 * t_0)) * cos(t_1);
return 2.0 * ((pow(t_3, 3.0) - pow((0.75 * (0.5 - (0.5 * cos((2.0 * t_1))))), 1.5)) / (pow(t_3, 2.0) + ((2.0 * t_2) * fma(2.0, t_2, t_3))));
}
function code(g, h) t_0 = Float64(sqrt(3.0) / 2.0) t_1 = Float64(acos(Float64(g / Float64(-h))) * 0.3333333333333333) t_2 = Float64(Float64(t_0 * 0.5) * sin(t_1)) t_3 = Float64(Float64(0.25 - Float64(t_0 * t_0)) * cos(t_1)) return Float64(2.0 * Float64(Float64((t_3 ^ 3.0) - (Float64(0.75 * Float64(0.5 - Float64(0.5 * cos(Float64(2.0 * t_1))))) ^ 1.5)) / Float64((t_3 ^ 2.0) + Float64(Float64(2.0 * t_2) * fma(2.0, t_2, t_3))))) end
code[g_, h_] := Block[{t$95$0 = N[(N[Sqrt[3.0], $MachinePrecision] / 2.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[ArcCos[N[(g / (-h)), $MachinePrecision]], $MachinePrecision] * 0.3333333333333333), $MachinePrecision]}, Block[{t$95$2 = N[(N[(t$95$0 * 0.5), $MachinePrecision] * N[Sin[t$95$1], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(0.25 - N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision] * N[Cos[t$95$1], $MachinePrecision]), $MachinePrecision]}, N[(2.0 * N[(N[(N[Power[t$95$3, 3.0], $MachinePrecision] - N[Power[N[(0.75 * N[(0.5 - N[(0.5 * N[Cos[N[(2.0 * t$95$1), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1.5], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$3, 2.0], $MachinePrecision] + N[(N[(2.0 * t$95$2), $MachinePrecision] * N[(2.0 * t$95$2 + t$95$3), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\sqrt{3}}{2}\\
t_1 := \cos^{-1} \left(\frac{g}{-h}\right) \cdot 0.3333333333333333\\
t_2 := \left(t\_0 \cdot 0.5\right) \cdot \sin t\_1\\
t_3 := \left(0.25 - t\_0 \cdot t\_0\right) \cdot \cos t\_1\\
2 \cdot \frac{{t\_3}^{3} - {\left(0.75 \cdot \left(0.5 - 0.5 \cdot \cos \left(2 \cdot t\_1\right)\right)\right)}^{1.5}}{{t\_3}^{2} + \left(2 \cdot t\_2\right) \cdot \mathsf{fma}\left(2, t\_2, t\_3\right)}
\end{array}
\end{array}
Initial program 98.5%
Applied rewrites99.9%
lift-pow.f64N/A
metadata-evalN/A
metadata-evalN/A
pow-sqrN/A
pow-prod-downN/A
lower-pow.f64N/A
Applied rewrites100.0%
(FPCore (g h)
:precision binary64
(let* ((t_0 (acos (/ g (- h))))
(t_1 (cos (* (fma PI -2.0 t_0) -0.3333333333333333))))
(*
t_1
(/
(/ 2.0 t_1)
(/ 1.0 (cos (fma t_0 0.3333333333333333 (* PI 0.6666666666666666))))))))
double code(double g, double h) {
double t_0 = acos((g / -h));
double t_1 = cos((fma(((double) M_PI), -2.0, t_0) * -0.3333333333333333));
return t_1 * ((2.0 / t_1) / (1.0 / cos(fma(t_0, 0.3333333333333333, (((double) M_PI) * 0.6666666666666666)))));
}
function code(g, h) t_0 = acos(Float64(g / Float64(-h))) t_1 = cos(Float64(fma(pi, -2.0, t_0) * -0.3333333333333333)) return Float64(t_1 * Float64(Float64(2.0 / t_1) / Float64(1.0 / cos(fma(t_0, 0.3333333333333333, Float64(pi * 0.6666666666666666)))))) end
code[g_, h_] := Block[{t$95$0 = N[ArcCos[N[(g / (-h)), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[Cos[N[(N[(Pi * -2.0 + t$95$0), $MachinePrecision] * -0.3333333333333333), $MachinePrecision]], $MachinePrecision]}, N[(t$95$1 * N[(N[(2.0 / t$95$1), $MachinePrecision] / N[(1.0 / N[Cos[N[(t$95$0 * 0.3333333333333333 + N[(Pi * 0.6666666666666666), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos^{-1} \left(\frac{g}{-h}\right)\\
t_1 := \cos \left(\mathsf{fma}\left(\pi, -2, t\_0\right) \cdot -0.3333333333333333\right)\\
t\_1 \cdot \frac{\frac{2}{t\_1}}{\frac{1}{\cos \left(\mathsf{fma}\left(t\_0, 0.3333333333333333, \pi \cdot 0.6666666666666666\right)\right)}}
\end{array}
\end{array}
Initial program 98.5%
Applied rewrites98.4%
lift-*.f64N/A
lift-/.f64N/A
div-invN/A
lift-/.f64N/A
Applied rewrites98.4%
lift-*.f64N/A
remove-double-divN/A
lift-/.f64N/A
div-invN/A
Applied rewrites99.9%
Final simplification99.9%
herbie shell --seed 2024225
(FPCore (g h)
:name "2-ancestry mixing, negative discriminant"
:precision binary64
(* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))