
(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 2 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 (* 2.0 (sin (fma PI -0.16666666666666666 (* (acos (/ (- g) h)) -0.3333333333333333)))))
double code(double g, double h) {
return 2.0 * sin(fma(((double) M_PI), -0.16666666666666666, (acos((-g / h)) * -0.3333333333333333)));
}
function code(g, h) return Float64(2.0 * sin(fma(pi, -0.16666666666666666, Float64(acos(Float64(Float64(-g) / h)) * -0.3333333333333333)))) end
code[g_, h_] := N[(2.0 * N[Sin[N[(Pi * -0.16666666666666666 + N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] * -0.3333333333333333), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \sin \left(\mathsf{fma}\left(\pi, -0.16666666666666666, \cos^{-1} \left(\frac{-g}{h}\right) \cdot -0.3333333333333333\right)\right)
\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%
Applied rewrites98.4%
Applied rewrites100.0%
lift-fma.f64N/A
lift-*.f64N/A
*-commutativeN/A
fp-cancel-sign-sub-invN/A
*-commutativeN/A
distribute-rgt-out--N/A
distribute-lft-out--N/A
fp-cancel-sub-sign-invN/A
lift-*.f64N/A
associate-*r*N/A
*-commutativeN/A
distribute-lft-neg-inN/A
distribute-rgt-neg-inN/A
lift-*.f64N/A
remove-double-negN/A
lower-fma.f64N/A
metadata-eval100.0
lift-*.f64N/A
Applied rewrites100.0%
(FPCore (g h) :precision binary64 (* (sin (* (+ PI (asin (/ g h))) -0.3333333333333333)) 2.0))
double code(double g, double h) {
return sin(((((double) M_PI) + asin((g / h))) * -0.3333333333333333)) * 2.0;
}
public static double code(double g, double h) {
return Math.sin(((Math.PI + Math.asin((g / h))) * -0.3333333333333333)) * 2.0;
}
def code(g, h): return math.sin(((math.pi + math.asin((g / h))) * -0.3333333333333333)) * 2.0
function code(g, h) return Float64(sin(Float64(Float64(pi + asin(Float64(g / h))) * -0.3333333333333333)) * 2.0) end
function tmp = code(g, h) tmp = sin(((pi + asin((g / h))) * -0.3333333333333333)) * 2.0; end
code[g_, h_] := N[(N[Sin[N[(N[(Pi + N[ArcSin[N[(g / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -0.3333333333333333), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
\\
\sin \left(\left(\pi + \sin^{-1} \left(\frac{g}{h}\right)\right) \cdot -0.3333333333333333\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%
Applied rewrites98.4%
Applied rewrites100.0%
Applied rewrites100.0%
herbie shell --seed 2025157
(FPCore (g h)
:name "2-ancestry mixing, negative discriminant"
:precision binary64
(* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))