
(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}
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 (* (sin (fma (fma 2.0 PI (acos (/ (- g) h))) -0.3333333333333333 (* 0.5 PI))) 2.0))
double code(double g, double h) {
return sin(fma(fma(2.0, ((double) M_PI), acos((-g / h))), -0.3333333333333333, (0.5 * ((double) M_PI)))) * 2.0;
}
function code(g, h) return Float64(sin(fma(fma(2.0, pi, acos(Float64(Float64(-g) / h))), -0.3333333333333333, Float64(0.5 * pi))) * 2.0) end
code[g_, h_] := N[(N[Sin[N[(N[(2.0 * Pi + N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -0.3333333333333333 + N[(0.5 * Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
\\
\sin \left(\mathsf{fma}\left(\mathsf{fma}\left(2, \pi, \cos^{-1} \left(\frac{-g}{h}\right)\right), -0.3333333333333333, 0.5 \cdot \pi\right)\right) \cdot 2
\end{array}
Initial program 98.5%
lift-cos.f64N/A
cos-neg-revN/A
sin-+PI/2-revN/A
lower-sin.f64N/A
lower-+.f64N/A
Applied rewrites98.5%
lift-*.f64N/A
*-commutativeN/A
lower-*.f6498.5
lift-+.f64N/A
lift-/.f64N/A
mult-flipN/A
lower-fma.f64N/A
lift-fma.f64N/A
*-commutativeN/A
lower-fma.f64N/A
metadata-eval99.9
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.9
Applied rewrites99.9%
(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}
Initial program 98.5%
lift-+.f64N/A
lift-/.f64N/A
lift-/.f64N/A
div-add-revN/A
lower-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f6498.5
Applied rewrites98.5%
(FPCore (g h) :precision binary64 (* 2.0 (cos (* (fma PI 2.0 (acos (/ (- g) h))) 0.3333333333333333))))
double code(double g, double h) {
return 2.0 * cos((fma(((double) M_PI), 2.0, acos((-g / h))) * 0.3333333333333333));
}
function code(g, h) return Float64(2.0 * cos(Float64(fma(pi, 2.0, acos(Float64(Float64(-g) / h))) * 0.3333333333333333))) end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(Pi * 2.0 + N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \cos \left(\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot 0.3333333333333333\right)
\end{array}
Initial program 98.5%
lift-+.f64N/A
lift-/.f64N/A
lift-/.f64N/A
div-add-revN/A
mult-flipN/A
lower-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f64N/A
metadata-eval98.5
Applied rewrites98.5%
(FPCore (g h) :precision binary64 (* (sin (fma (acos (/ (- g) h)) 0.3333333333333333 (* PI 1.1666666666666667))) 2.0))
double code(double g, double h) {
return sin(fma(acos((-g / h)), 0.3333333333333333, (((double) M_PI) * 1.1666666666666667))) * 2.0;
}
function code(g, h) return Float64(sin(fma(acos(Float64(Float64(-g) / h)), 0.3333333333333333, Float64(pi * 1.1666666666666667))) * 2.0) end
code[g_, h_] := N[(N[Sin[N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] * 0.3333333333333333 + N[(Pi * 1.1666666666666667), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
\\
\sin \left(\mathsf{fma}\left(\cos^{-1} \left(\frac{-g}{h}\right), 0.3333333333333333, \pi \cdot 1.1666666666666667\right)\right) \cdot 2
\end{array}
Initial program 98.5%
lift-cos.f64N/A
sin-+PI/2-revN/A
lower-sin.f64N/A
lift-+.f64N/A
+-commutativeN/A
associate-+l+N/A
lift-/.f64N/A
div-flipN/A
associate-/r/N/A
lower-fma.f64N/A
metadata-evalN/A
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/l*N/A
Applied rewrites97.5%
lift-*.f64N/A
*-commutativeN/A
lower-*.f6497.5
lift-fma.f64N/A
*-commutativeN/A
lower-fma.f6497.5
lift-fma.f64N/A
lift-*.f64N/A
distribute-lft-outN/A
lower-*.f64N/A
metadata-eval97.6
Applied rewrites97.6%
herbie shell --seed 2025154
(FPCore (g h)
:name "2-ancestry mixing, negative discriminant"
:precision binary64
(* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))