
(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
(let* ((t_0 (/ (sqrt 3.0) 2.0))
(t_1 (* -0.3333333333333333 (acos (/ (- g) h)))))
(*
2.0
(/
(-
(* (* (cos t_1) (- 0.25 (* t_0 t_0))) 2.0)
(-
(cos (fma 0.6666666666666666 PI t_1))
(cos (* (fma PI 2.5 (asin (/ g h))) -0.3333333333333333))))
2.0))))
double code(double g, double h) {
double t_0 = sqrt(3.0) / 2.0;
double t_1 = -0.3333333333333333 * acos((-g / h));
return 2.0 * ((((cos(t_1) * (0.25 - (t_0 * t_0))) * 2.0) - (cos(fma(0.6666666666666666, ((double) M_PI), t_1)) - cos((fma(((double) M_PI), 2.5, asin((g / h))) * -0.3333333333333333)))) / 2.0);
}
function code(g, h) t_0 = Float64(sqrt(3.0) / 2.0) t_1 = Float64(-0.3333333333333333 * acos(Float64(Float64(-g) / h))) return Float64(2.0 * Float64(Float64(Float64(Float64(cos(t_1) * Float64(0.25 - Float64(t_0 * t_0))) * 2.0) - Float64(cos(fma(0.6666666666666666, pi, t_1)) - cos(Float64(fma(pi, 2.5, asin(Float64(g / h))) * -0.3333333333333333)))) / 2.0)) end
code[g_, h_] := Block[{t$95$0 = N[(N[Sqrt[3.0], $MachinePrecision] / 2.0), $MachinePrecision]}, Block[{t$95$1 = N[(-0.3333333333333333 * N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(2.0 * N[(N[(N[(N[(N[Cos[t$95$1], $MachinePrecision] * N[(0.25 - N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 2.0), $MachinePrecision] - N[(N[Cos[N[(0.6666666666666666 * Pi + t$95$1), $MachinePrecision]], $MachinePrecision] - N[Cos[N[(N[(Pi * 2.5 + N[ArcSin[N[(g / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -0.3333333333333333), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\sqrt{3}}{2}\\
t_1 := -0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\\
2 \cdot \frac{\left(\cos t\_1 \cdot \left(0.25 - t\_0 \cdot t\_0\right)\right) \cdot 2 - \left(\cos \left(\mathsf{fma}\left(0.6666666666666666, \pi, t\_1\right)\right) - \cos \left(\mathsf{fma}\left(\pi, 2.5, \sin^{-1} \left(\frac{g}{h}\right)\right) \cdot -0.3333333333333333\right)\right)}{2}
\end{array}
\end{array}
Initial program 98.5%
Applied rewrites100.0%
(FPCore (g h) :precision binary64 (* (sin (/ (- (* (* -0.3333333333333333 PI) 3.0) (asin (/ g h))) 3.0)) 2.0))
double code(double g, double h) {
return sin(((((-0.3333333333333333 * ((double) M_PI)) * 3.0) - asin((g / h))) / 3.0)) * 2.0;
}
public static double code(double g, double h) {
return Math.sin(((((-0.3333333333333333 * Math.PI) * 3.0) - Math.asin((g / h))) / 3.0)) * 2.0;
}
def code(g, h): return math.sin(((((-0.3333333333333333 * math.pi) * 3.0) - math.asin((g / h))) / 3.0)) * 2.0
function code(g, h) return Float64(sin(Float64(Float64(Float64(Float64(-0.3333333333333333 * pi) * 3.0) - asin(Float64(g / h))) / 3.0)) * 2.0) end
function tmp = code(g, h) tmp = sin(((((-0.3333333333333333 * pi) * 3.0) - asin((g / h))) / 3.0)) * 2.0; end
code[g_, h_] := N[(N[Sin[N[(N[(N[(N[(-0.3333333333333333 * Pi), $MachinePrecision] * 3.0), $MachinePrecision] - N[ArcSin[N[(g / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / 3.0), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
\\
\sin \left(\frac{\left(-0.3333333333333333 \cdot \pi\right) \cdot 3 - \sin^{-1} \left(\frac{g}{h}\right)}{3}\right) \cdot 2
\end{array}
Initial program 98.5%
Applied rewrites98.4%
lift-cos.f64N/A
sin-+PI/2-revN/A
lower-sin.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-fma.f64N/A
distribute-lft-inN/A
associate-+l+N/A
*-commutativeN/A
associate-*r*N/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f64N/A
metadata-evalN/A
*-commutativeN/A
lower-fma.f64N/A
lift-PI.f64N/A
mult-flip-revN/A
Applied rewrites98.5%
lift-fma.f64N/A
*-commutativeN/A
lift-fma.f64N/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
metadata-evalN/A
mult-flipN/A
lift-PI.f64N/A
+-commutativeN/A
associate-+r+N/A
lift-PI.f64N/A
mult-flipN/A
metadata-evalN/A
distribute-lft-outN/A
metadata-evalN/A
lower-fma.f64100.0
lift-*.f64N/A
*-commutativeN/A
lower-*.f64100.0
Applied rewrites100.0%
lift-fma.f64N/A
add-flipN/A
lift-*.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
metadata-evalN/A
metadata-evalN/A
mult-flip-revN/A
sub-to-fractionN/A
lower-/.f64N/A
lower--.f64N/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64100.0
Applied rewrites100.0%
(FPCore (g h) :precision binary64 (* (sin (fma PI -0.3333333333333333 (* -0.3333333333333333 (asin (/ g h))))) 2.0))
double code(double g, double h) {
return sin(fma(((double) M_PI), -0.3333333333333333, (-0.3333333333333333 * asin((g / h))))) * 2.0;
}
function code(g, h) return Float64(sin(fma(pi, -0.3333333333333333, Float64(-0.3333333333333333 * asin(Float64(g / h))))) * 2.0) end
code[g_, h_] := N[(N[Sin[N[(Pi * -0.3333333333333333 + N[(-0.3333333333333333 * N[ArcSin[N[(g / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
\\
\sin \left(\mathsf{fma}\left(\pi, -0.3333333333333333, -0.3333333333333333 \cdot \sin^{-1} \left(\frac{g}{h}\right)\right)\right) \cdot 2
\end{array}
Initial program 98.5%
Applied rewrites98.4%
lift-cos.f64N/A
sin-+PI/2-revN/A
lower-sin.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-fma.f64N/A
distribute-lft-inN/A
associate-+l+N/A
*-commutativeN/A
associate-*r*N/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f64N/A
metadata-evalN/A
*-commutativeN/A
lower-fma.f64N/A
lift-PI.f64N/A
mult-flip-revN/A
Applied rewrites98.5%
lift-fma.f64N/A
*-commutativeN/A
lift-fma.f64N/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
metadata-evalN/A
mult-flipN/A
lift-PI.f64N/A
+-commutativeN/A
associate-+r+N/A
lift-PI.f64N/A
mult-flipN/A
metadata-evalN/A
distribute-lft-outN/A
metadata-evalN/A
lower-fma.f64100.0
lift-*.f64N/A
*-commutativeN/A
lower-*.f64100.0
Applied rewrites100.0%
(FPCore (g h) :precision binary64 (* (sin (* (+ (asin (/ g h)) PI) -0.3333333333333333)) 2.0))
double code(double g, double h) {
return sin(((asin((g / h)) + ((double) M_PI)) * -0.3333333333333333)) * 2.0;
}
public static double code(double g, double h) {
return Math.sin(((Math.asin((g / h)) + Math.PI) * -0.3333333333333333)) * 2.0;
}
def code(g, h): return math.sin(((math.asin((g / h)) + math.pi) * -0.3333333333333333)) * 2.0
function code(g, h) return Float64(sin(Float64(Float64(asin(Float64(g / h)) + pi) * -0.3333333333333333)) * 2.0) end
function tmp = code(g, h) tmp = sin(((asin((g / h)) + pi) * -0.3333333333333333)) * 2.0; end
code[g_, h_] := N[(N[Sin[N[(N[(N[ArcSin[N[(g / h), $MachinePrecision]], $MachinePrecision] + Pi), $MachinePrecision] * -0.3333333333333333), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
\\
\sin \left(\left(\sin^{-1} \left(\frac{g}{h}\right) + \pi\right) \cdot -0.3333333333333333\right) \cdot 2
\end{array}
Initial program 98.5%
Applied rewrites98.4%
lift-cos.f64N/A
sin-+PI/2-revN/A
lower-sin.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-fma.f64N/A
distribute-lft-inN/A
associate-+l+N/A
*-commutativeN/A
associate-*r*N/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f64N/A
metadata-evalN/A
*-commutativeN/A
lower-fma.f64N/A
lift-PI.f64N/A
mult-flip-revN/A
Applied rewrites98.5%
lift-fma.f64N/A
*-commutativeN/A
lift-fma.f64N/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
metadata-evalN/A
mult-flipN/A
lift-PI.f64N/A
+-commutativeN/A
associate-+r+N/A
lift-PI.f64N/A
mult-flipN/A
metadata-evalN/A
distribute-lft-outN/A
metadata-evalN/A
lower-fma.f64100.0
lift-*.f64N/A
*-commutativeN/A
lower-*.f64100.0
Applied rewrites100.0%
lift-fma.f64N/A
lift-*.f64N/A
*-commutativeN/A
distribute-rgt-outN/A
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
lower-+.f64100.0
Applied rewrites100.0%
herbie shell --seed 2025150
(FPCore (g h)
:name "2-ancestry mixing, negative discriminant"
:precision binary64
(* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))