
(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 3 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 (* 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(-Float64(g / 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}
Initial program 98.5%
cos-sumN/A
sub-negN/A
accelerator-lowering-fma.f64N/A
Applied egg-rr98.4%
Taylor expanded in g around 0
*-commutativeN/A
*-commutativeN/A
cancel-sign-sub-invN/A
unpow2N/A
rem-square-sqrtN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
distribute-lft-outN/A
associate-*r*N/A
Simplified99.9%
(FPCore (g h) :precision binary64 (* (cos (* (fma (acos (- (/ g h))) (/ -1.5 PI) -3.0) (* PI -0.2222222222222222))) 2.0))
double code(double g, double h) {
return cos((fma(acos(-(g / h)), (-1.5 / ((double) M_PI)), -3.0) * (((double) M_PI) * -0.2222222222222222))) * 2.0;
}
function code(g, h) return Float64(cos(Float64(fma(acos(Float64(-Float64(g / h))), Float64(-1.5 / pi), -3.0) * Float64(pi * -0.2222222222222222))) * 2.0) end
code[g_, h_] := N[(N[Cos[N[(N[(N[ArcCos[(-N[(g / h), $MachinePrecision])], $MachinePrecision] * N[(-1.5 / Pi), $MachinePrecision] + -3.0), $MachinePrecision] * N[(Pi * -0.2222222222222222), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
\\
\cos \left(\mathsf{fma}\left(\cos^{-1} \left(-\frac{g}{h}\right), \frac{-1.5}{\pi}, -3\right) \cdot \left(\pi \cdot -0.2222222222222222\right)\right) \cdot 2
\end{array}
Initial program 98.5%
+-commutativeN/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
frac-addN/A
/-lowering-/.f64N/A
Applied egg-rr98.5%
*-commutativeN/A
*-lowering-*.f64N/A
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (g h) :precision binary64 (* 2.0 (cos (* 0.3333333333333333 (fma 2.0 PI (acos (- (/ g h))))))))
double code(double g, double h) {
return 2.0 * cos((0.3333333333333333 * fma(2.0, ((double) M_PI), acos(-(g / h)))));
}
function code(g, h) return Float64(2.0 * cos(Float64(0.3333333333333333 * fma(2.0, pi, acos(Float64(-Float64(g / h))))))) end
code[g_, h_] := N[(2.0 * N[Cos[N[(0.3333333333333333 * N[(2.0 * Pi + N[ArcCos[(-N[(g / h), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \cos \left(0.3333333333333333 \cdot \mathsf{fma}\left(2, \pi, \cos^{-1} \left(-\frac{g}{h}\right)\right)\right)
\end{array}
Initial program 98.5%
div-invN/A
div-invN/A
distribute-rgt-outN/A
*-lowering-*.f64N/A
metadata-evalN/A
accelerator-lowering-fma.f64N/A
PI-lowering-PI.f64N/A
acos-lowering-acos.f64N/A
/-lowering-/.f64N/A
neg-lowering-neg.f6498.5
Applied egg-rr98.5%
Final simplification98.5%
herbie shell --seed 2024198
(FPCore (g h)
:name "2-ancestry mixing, negative discriminant"
:precision binary64
(* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))