
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0))));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin(Math.sqrt(((1.0 - x) / 2.0))));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin(math.sqrt(((1.0 - x) / 2.0))))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(sqrt(Float64(Float64(1.0 - x) / 2.0))))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0)))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[Sqrt[N[(N[(1.0 - x), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\sqrt{\frac{1 - x}{2}}\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0))));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin(Math.sqrt(((1.0 - x) / 2.0))));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin(math.sqrt(((1.0 - x) / 2.0))))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(sqrt(Float64(Float64(1.0 - x) / 2.0))))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0)))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[Sqrt[N[(N[(1.0 - x), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\sqrt{\frac{1 - x}{2}}\right)
\end{array}
(FPCore (x)
:precision binary64
(let* ((t_0 (asin (sqrt (- 0.5 (* 0.5 x))))))
(/
(- (cbrt (pow (* PI 0.5) 6.0)) (pow (* 2.0 t_0) 2.0))
(fma 2.0 t_0 (* 0.5 (cbrt (pow PI 3.0)))))))
double code(double x) {
double t_0 = asin(sqrt((0.5 - (0.5 * x))));
return (cbrt(pow((((double) M_PI) * 0.5), 6.0)) - pow((2.0 * t_0), 2.0)) / fma(2.0, t_0, (0.5 * cbrt(pow(((double) M_PI), 3.0))));
}
function code(x) t_0 = asin(sqrt(Float64(0.5 - Float64(0.5 * x)))) return Float64(Float64(cbrt((Float64(pi * 0.5) ^ 6.0)) - (Float64(2.0 * t_0) ^ 2.0)) / fma(2.0, t_0, Float64(0.5 * cbrt((pi ^ 3.0))))) end
code[x_] := Block[{t$95$0 = N[ArcSin[N[Sqrt[N[(0.5 - N[(0.5 * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]}, N[(N[(N[Power[N[Power[N[(Pi * 0.5), $MachinePrecision], 6.0], $MachinePrecision], 1/3], $MachinePrecision] - N[Power[N[(2.0 * t$95$0), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] / N[(2.0 * t$95$0 + N[(0.5 * N[Power[N[Power[Pi, 3.0], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin^{-1} \left(\sqrt{0.5 - 0.5 \cdot x}\right)\\
\frac{\sqrt[3]{{\left(\pi \cdot 0.5\right)}^{6}} - {\left(2 \cdot t\_0\right)}^{2}}{\mathsf{fma}\left(2, t\_0, 0.5 \cdot \sqrt[3]{{\pi}^{3}}\right)}
\end{array}
\end{array}
Initial program 7.0%
flip--7.0%
pow27.0%
div-inv7.0%
metadata-eval7.0%
pow27.0%
div-sub7.0%
metadata-eval7.0%
div-inv7.0%
metadata-eval7.0%
+-commutative7.0%
Applied egg-rr7.0%
add-cbrt-cube8.4%
pow38.4%
pow-pow8.4%
metadata-eval8.4%
Applied egg-rr8.4%
add-cbrt-cube8.4%
pow38.4%
Applied egg-rr8.4%
Final simplification8.4%
(FPCore (x) :precision binary64 (let* ((t_0 (* 2.0 (asin (sqrt (- 0.5 (* 0.5 x))))))) (/ (- (cbrt (pow (* PI 0.5) 6.0)) (pow t_0 2.0)) (+ (* PI 0.5) t_0))))
double code(double x) {
double t_0 = 2.0 * asin(sqrt((0.5 - (0.5 * x))));
return (cbrt(pow((((double) M_PI) * 0.5), 6.0)) - pow(t_0, 2.0)) / ((((double) M_PI) * 0.5) + t_0);
}
public static double code(double x) {
double t_0 = 2.0 * Math.asin(Math.sqrt((0.5 - (0.5 * x))));
return (Math.cbrt(Math.pow((Math.PI * 0.5), 6.0)) - Math.pow(t_0, 2.0)) / ((Math.PI * 0.5) + t_0);
}
function code(x) t_0 = Float64(2.0 * asin(sqrt(Float64(0.5 - Float64(0.5 * x))))) return Float64(Float64(cbrt((Float64(pi * 0.5) ^ 6.0)) - (t_0 ^ 2.0)) / Float64(Float64(pi * 0.5) + t_0)) end
code[x_] := Block[{t$95$0 = N[(2.0 * N[ArcSin[N[Sqrt[N[(0.5 - N[(0.5 * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[N[Power[N[(Pi * 0.5), $MachinePrecision], 6.0], $MachinePrecision], 1/3], $MachinePrecision] - N[Power[t$95$0, 2.0], $MachinePrecision]), $MachinePrecision] / N[(N[(Pi * 0.5), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 2 \cdot \sin^{-1} \left(\sqrt{0.5 - 0.5 \cdot x}\right)\\
\frac{\sqrt[3]{{\left(\pi \cdot 0.5\right)}^{6}} - {t\_0}^{2}}{\pi \cdot 0.5 + t\_0}
\end{array}
\end{array}
Initial program 7.0%
flip--7.0%
pow27.0%
div-inv7.0%
metadata-eval7.0%
pow27.0%
div-sub7.0%
metadata-eval7.0%
div-inv7.0%
metadata-eval7.0%
+-commutative7.0%
Applied egg-rr7.0%
add-cbrt-cube8.4%
pow38.4%
pow-pow8.4%
metadata-eval8.4%
Applied egg-rr8.4%
add-cbrt-cube8.4%
pow38.4%
Applied egg-rr8.4%
fma-undefine8.4%
*-commutative8.4%
rem-cbrt-cube8.4%
Applied egg-rr8.4%
Final simplification8.4%
(FPCore (x) :precision binary64 (pow (cbrt (fma PI 0.5 (* (- (* PI 0.5) (acos (sqrt (+ 0.5 (* x -0.5))))) -2.0))) 3.0))
double code(double x) {
return pow(cbrt(fma(((double) M_PI), 0.5, (((((double) M_PI) * 0.5) - acos(sqrt((0.5 + (x * -0.5))))) * -2.0))), 3.0);
}
function code(x) return cbrt(fma(pi, 0.5, Float64(Float64(Float64(pi * 0.5) - acos(sqrt(Float64(0.5 + Float64(x * -0.5))))) * -2.0))) ^ 3.0 end
code[x_] := N[Power[N[Power[N[(Pi * 0.5 + N[(N[(N[(Pi * 0.5), $MachinePrecision] - N[ArcCos[N[Sqrt[N[(0.5 + N[(x * -0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision], 3.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\sqrt[3]{\mathsf{fma}\left(\pi, 0.5, \left(\pi \cdot 0.5 - \cos^{-1} \left(\sqrt{0.5 + x \cdot -0.5}\right)\right) \cdot -2\right)}\right)}^{3}
\end{array}
Initial program 7.0%
add-cube-cbrt7.0%
pow37.0%
Applied egg-rr7.0%
asin-acos8.4%
div-inv8.4%
metadata-eval8.4%
sub-neg8.4%
distribute-rgt-neg-in8.4%
metadata-eval8.4%
Applied egg-rr8.4%
(FPCore (x) :precision binary64 (+ (/ PI 2.0) (* 2.0 (- (acos (sqrt (- 0.5 (* 0.5 x)))) (* PI 0.5)))))
double code(double x) {
return (((double) M_PI) / 2.0) + (2.0 * (acos(sqrt((0.5 - (0.5 * x)))) - (((double) M_PI) * 0.5)));
}
public static double code(double x) {
return (Math.PI / 2.0) + (2.0 * (Math.acos(Math.sqrt((0.5 - (0.5 * x)))) - (Math.PI * 0.5)));
}
def code(x): return (math.pi / 2.0) + (2.0 * (math.acos(math.sqrt((0.5 - (0.5 * x)))) - (math.pi * 0.5)))
function code(x) return Float64(Float64(pi / 2.0) + Float64(2.0 * Float64(acos(sqrt(Float64(0.5 - Float64(0.5 * x)))) - Float64(pi * 0.5)))) end
function tmp = code(x) tmp = (pi / 2.0) + (2.0 * (acos(sqrt((0.5 - (0.5 * x)))) - (pi * 0.5))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] + N[(2.0 * N[(N[ArcCos[N[Sqrt[N[(0.5 - N[(0.5 * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] - N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} + 2 \cdot \left(\cos^{-1} \left(\sqrt{0.5 - 0.5 \cdot x}\right) - \pi \cdot 0.5\right)
\end{array}
Initial program 7.0%
asin-acos8.4%
div-inv8.4%
metadata-eval8.4%
div-sub8.4%
metadata-eval8.4%
div-inv8.4%
metadata-eval8.4%
Applied egg-rr8.4%
Final simplification8.4%
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0))));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin(Math.sqrt(((1.0 - x) / 2.0))));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin(math.sqrt(((1.0 - x) / 2.0))))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(sqrt(Float64(Float64(1.0 - x) / 2.0))))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin(sqrt(((1.0 - x) / 2.0)))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[Sqrt[N[(N[(1.0 - x), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\sqrt{\frac{1 - x}{2}}\right)
\end{array}
Initial program 7.0%
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (sqrt 0.5)))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin(sqrt(0.5)));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin(Math.sqrt(0.5)));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin(math.sqrt(0.5)))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(sqrt(0.5)))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin(sqrt(0.5))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[Sqrt[0.5], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\sqrt{0.5}\right)
\end{array}
Initial program 7.0%
Taylor expanded in x around 0 4.1%
(FPCore (x) :precision binary64 (+ (* PI 0.5) (* 2.0 (asin (sqrt 0.5)))))
double code(double x) {
return (((double) M_PI) * 0.5) + (2.0 * asin(sqrt(0.5)));
}
public static double code(double x) {
return (Math.PI * 0.5) + (2.0 * Math.asin(Math.sqrt(0.5)));
}
def code(x): return (math.pi * 0.5) + (2.0 * math.asin(math.sqrt(0.5)))
function code(x) return Float64(Float64(pi * 0.5) + Float64(2.0 * asin(sqrt(0.5)))) end
function tmp = code(x) tmp = (pi * 0.5) + (2.0 * asin(sqrt(0.5))); end
code[x_] := N[(N[(Pi * 0.5), $MachinePrecision] + N[(2.0 * N[ArcSin[N[Sqrt[0.5], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\pi \cdot 0.5 + 2 \cdot \sin^{-1} \left(\sqrt{0.5}\right)
\end{array}
Initial program 7.0%
expm1-log1p-u7.0%
div-inv7.0%
metadata-eval7.0%
fmm-def7.0%
*-commutative7.0%
distribute-rgt-neg-in7.0%
div-sub7.0%
metadata-eval7.0%
div-inv7.0%
metadata-eval7.0%
metadata-eval7.0%
Applied egg-rr7.0%
expm1-log1p-u7.0%
fma-undefine7.0%
add-sqr-sqrt0.0%
sqrt-unprod3.8%
swap-sqr3.8%
pow23.8%
metadata-eval3.8%
metadata-eval3.8%
unpow-prod-down3.8%
*-commutative3.8%
unpow-prod-down3.8%
sqrt-prod3.8%
metadata-eval3.8%
metadata-eval3.8%
Applied egg-rr3.8%
Taylor expanded in x around 0 3.8%
(FPCore (x) :precision binary64 (asin x))
double code(double x) {
return asin(x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = asin(x)
end function
public static double code(double x) {
return Math.asin(x);
}
def code(x): return math.asin(x)
function code(x) return asin(x) end
function tmp = code(x) tmp = asin(x); end
code[x_] := N[ArcSin[x], $MachinePrecision]
\begin{array}{l}
\\
\sin^{-1} x
\end{array}
herbie shell --seed 2024165
(FPCore (x)
:name "Ian Simplification"
:precision binary64
:alt
(! :herbie-platform default (asin x))
(- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))