
(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 (acos (/ g (- h))))
(t_1 (/ (sqrt 3.0) 2.0))
(t_2 (* 0.3333333333333333 t_0))
(t_3 (sin t_2))
(t_4 (* (- 0.25 (* t_1 t_1)) (cos t_2))))
(*
2.0
(/
(-
(pow t_4 3.0)
(pow (fma (cos (* t_0 0.6666666666666666)) -0.375 0.375) 1.5))
(+
(pow t_4 2.0)
(* (* 0.5 (* (sqrt 3.0) t_3)) (fma 2.0 (* t_3 (* t_1 0.5)) t_4)))))))
double code(double g, double h) {
double t_0 = acos((g / -h));
double t_1 = sqrt(3.0) / 2.0;
double t_2 = 0.3333333333333333 * t_0;
double t_3 = sin(t_2);
double t_4 = (0.25 - (t_1 * t_1)) * cos(t_2);
return 2.0 * ((pow(t_4, 3.0) - pow(fma(cos((t_0 * 0.6666666666666666)), -0.375, 0.375), 1.5)) / (pow(t_4, 2.0) + ((0.5 * (sqrt(3.0) * t_3)) * fma(2.0, (t_3 * (t_1 * 0.5)), t_4))));
}
function code(g, h) t_0 = acos(Float64(g / Float64(-h))) t_1 = Float64(sqrt(3.0) / 2.0) t_2 = Float64(0.3333333333333333 * t_0) t_3 = sin(t_2) t_4 = Float64(Float64(0.25 - Float64(t_1 * t_1)) * cos(t_2)) return Float64(2.0 * Float64(Float64((t_4 ^ 3.0) - (fma(cos(Float64(t_0 * 0.6666666666666666)), -0.375, 0.375) ^ 1.5)) / Float64((t_4 ^ 2.0) + Float64(Float64(0.5 * Float64(sqrt(3.0) * t_3)) * fma(2.0, Float64(t_3 * Float64(t_1 * 0.5)), t_4))))) end
code[g_, h_] := Block[{t$95$0 = N[ArcCos[N[(g / (-h)), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[Sqrt[3.0], $MachinePrecision] / 2.0), $MachinePrecision]}, Block[{t$95$2 = N[(0.3333333333333333 * t$95$0), $MachinePrecision]}, Block[{t$95$3 = N[Sin[t$95$2], $MachinePrecision]}, Block[{t$95$4 = N[(N[(0.25 - N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision] * N[Cos[t$95$2], $MachinePrecision]), $MachinePrecision]}, N[(2.0 * N[(N[(N[Power[t$95$4, 3.0], $MachinePrecision] - N[Power[N[(N[Cos[N[(t$95$0 * 0.6666666666666666), $MachinePrecision]], $MachinePrecision] * -0.375 + 0.375), $MachinePrecision], 1.5], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$4, 2.0], $MachinePrecision] + N[(N[(0.5 * N[(N[Sqrt[3.0], $MachinePrecision] * t$95$3), $MachinePrecision]), $MachinePrecision] * N[(2.0 * N[(t$95$3 * N[(t$95$1 * 0.5), $MachinePrecision]), $MachinePrecision] + t$95$4), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos^{-1} \left(\frac{g}{-h}\right)\\
t_1 := \frac{\sqrt{3}}{2}\\
t_2 := 0.3333333333333333 \cdot t\_0\\
t_3 := \sin t\_2\\
t_4 := \left(0.25 - t\_1 \cdot t\_1\right) \cdot \cos t\_2\\
2 \cdot \frac{{t\_4}^{3} - {\left(\mathsf{fma}\left(\cos \left(t\_0 \cdot 0.6666666666666666\right), -0.375, 0.375\right)\right)}^{1.5}}{{t\_4}^{2} + \left(0.5 \cdot \left(\sqrt{3} \cdot t\_3\right)\right) \cdot \mathsf{fma}\left(2, t\_3 \cdot \left(t\_1 \cdot 0.5\right), t\_4\right)}
\end{array}
\end{array}
Initial program 98.5%
Applied rewrites99.9%
lift-pow.f64N/A
sqr-powN/A
pow-prod-downN/A
lower-pow.f64N/A
Applied rewrites99.9%
Taylor expanded in g around 0
Applied rewrites99.9%
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
Applied rewrites99.9%
Final simplification99.9%
(FPCore (g h) :precision binary64 (* 2.0 (cos (/ (fma (acos (/ g (- h))) -3.0 (* PI -6.0)) -9.0))))
double code(double g, double h) {
return 2.0 * cos((fma(acos((g / -h)), -3.0, (((double) M_PI) * -6.0)) / -9.0));
}
function code(g, h) return Float64(2.0 * cos(Float64(fma(acos(Float64(g / Float64(-h))), -3.0, Float64(pi * -6.0)) / -9.0))) end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(N[ArcCos[N[(g / (-h)), $MachinePrecision]], $MachinePrecision] * -3.0 + N[(Pi * -6.0), $MachinePrecision]), $MachinePrecision] / -9.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \cos \left(\frac{\mathsf{fma}\left(\cos^{-1} \left(\frac{g}{-h}\right), -3, \pi \cdot -6\right)}{-9}\right)
\end{array}
Initial program 98.5%
lift-+.f64N/A
+-commutativeN/A
lift-/.f64N/A
lift-/.f64N/A
frac-2negN/A
frac-addN/A
lower-/.f64N/A
Applied rewrites98.5%
(FPCore (g h)
:precision binary64
(*
2.0
(cos
(fma
(* PI -0.1111111111111111)
-6.0
(* 0.3333333333333333 (acos (/ g (- h))))))))
double code(double g, double h) {
return 2.0 * cos(fma((((double) M_PI) * -0.1111111111111111), -6.0, (0.3333333333333333 * acos((g / -h)))));
}
function code(g, h) return Float64(2.0 * cos(fma(Float64(pi * -0.1111111111111111), -6.0, Float64(0.3333333333333333 * acos(Float64(g / Float64(-h))))))) end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(Pi * -0.1111111111111111), $MachinePrecision] * -6.0 + 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 \cdot -0.1111111111111111, -6, 0.3333333333333333 \cdot \cos^{-1} \left(\frac{g}{-h}\right)\right)\right)
\end{array}
Initial program 98.5%
lift-+.f64N/A
+-commutativeN/A
lift-/.f64N/A
lift-/.f64N/A
frac-2negN/A
frac-addN/A
lower-/.f64N/A
Applied rewrites98.5%
lift-/.f64N/A
clear-numN/A
associate-/r/N/A
lift-fma.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
lower-fma.f64N/A
metadata-evalN/A
lower-*.f64N/A
lower-*.f64N/A
metadata-eval98.5
Applied rewrites98.5%
lift-fma.f64N/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
lower-fma.f64N/A
lower-*.f6498.5
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
metadata-evalN/A
lift-*.f6498.5
lift-/.f64N/A
lift-neg.f64N/A
distribute-frac-neg2N/A
lower-neg.f64N/A
lower-/.f6498.5
Applied rewrites98.5%
Final simplification98.5%
(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}
Initial program 98.5%
lift-+.f64N/A
lift-/.f64N/A
div-invN/A
lift-*.f64N/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f64N/A
metadata-evalN/A
metadata-eval98.5
lift-/.f64N/A
div-invN/A
lower-*.f64N/A
lift-/.f64N/A
frac-2negN/A
lift-neg.f64N/A
remove-double-negN/A
lower-/.f64N/A
lower-neg.f64N/A
metadata-eval98.5
Applied rewrites98.5%
Final simplification98.5%
herbie shell --seed 2024237
(FPCore (g h)
:name "2-ancestry mixing, negative discriminant"
:precision binary64
(* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))