
(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 6 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 (+ (/ PI 2.0) (* 2.0 (- (acos (sqrt (+ 0.5 (* x -0.5)))) (/ PI 2.0)))))
double code(double x) {
return (((double) M_PI) / 2.0) + (2.0 * (acos(sqrt((0.5 + (x * -0.5)))) - (((double) M_PI) / 2.0)));
}
public static double code(double x) {
return (Math.PI / 2.0) + (2.0 * (Math.acos(Math.sqrt((0.5 + (x * -0.5)))) - (Math.PI / 2.0)));
}
def code(x): return (math.pi / 2.0) + (2.0 * (math.acos(math.sqrt((0.5 + (x * -0.5)))) - (math.pi / 2.0)))
function code(x) return Float64(Float64(pi / 2.0) + Float64(2.0 * Float64(acos(sqrt(Float64(0.5 + Float64(x * -0.5)))) - Float64(pi / 2.0)))) end
function tmp = code(x) tmp = (pi / 2.0) + (2.0 * (acos(sqrt((0.5 + (x * -0.5)))) - (pi / 2.0))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] + N[(2.0 * N[(N[ArcCos[N[Sqrt[N[(0.5 + N[(x * -0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] - N[(Pi / 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} + 2 \cdot \left(\cos^{-1} \left(\sqrt{0.5 + x \cdot -0.5}\right) - \frac{\pi}{2}\right)
\end{array}
Initial program 5.3%
asin-acos7.0%
add-cube-cbrt5.5%
associate-/l*5.5%
fma-neg5.5%
pow25.5%
div-sub5.5%
metadata-eval5.5%
div-inv5.5%
metadata-eval5.5%
Applied egg-rr5.5%
fma-neg5.5%
associate-*r/5.5%
unpow25.5%
rem-3cbrt-lft7.0%
sub-neg7.0%
distribute-rgt-neg-in7.0%
metadata-eval7.0%
Simplified7.0%
Final simplification7.0%
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (/ 1.0 (sqrt (/ 2.0 (- 1.0 x))))))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin((1.0 / sqrt((2.0 / (1.0 - x))))));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin((1.0 / Math.sqrt((2.0 / (1.0 - x))))));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin((1.0 / math.sqrt((2.0 / (1.0 - x))))))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(Float64(1.0 / sqrt(Float64(2.0 / Float64(1.0 - x))))))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin((1.0 / sqrt((2.0 / (1.0 - x)))))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[(1.0 / N[Sqrt[N[(2.0 / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\frac{1}{\sqrt{\frac{2}{1 - x}}}\right)
\end{array}
Initial program 5.3%
clear-num5.3%
sqrt-div5.6%
metadata-eval5.6%
Applied egg-rr5.6%
Final simplification5.6%
(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 5.3%
Final simplification5.3%
(FPCore (x) :precision binary64 (+ (/ PI 2.0) (* 2.0 (- (acos (sqrt 0.5)) (* PI 0.5)))))
double code(double x) {
return (((double) M_PI) / 2.0) + (2.0 * (acos(sqrt(0.5)) - (((double) M_PI) * 0.5)));
}
public static double code(double x) {
return (Math.PI / 2.0) + (2.0 * (Math.acos(Math.sqrt(0.5)) - (Math.PI * 0.5)));
}
def code(x): return (math.pi / 2.0) + (2.0 * (math.acos(math.sqrt(0.5)) - (math.pi * 0.5)))
function code(x) return Float64(Float64(pi / 2.0) + Float64(2.0 * Float64(acos(sqrt(0.5)) - Float64(pi * 0.5)))) end
function tmp = code(x) tmp = (pi / 2.0) + (2.0 * (acos(sqrt(0.5)) - (pi * 0.5))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] + N[(2.0 * N[(N[ArcCos[N[Sqrt[0.5], $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}\right) - \pi \cdot 0.5\right)
\end{array}
Initial program 5.3%
Taylor expanded in x around 0 3.8%
asin-acos5.4%
div-inv5.4%
metadata-eval5.4%
Applied egg-rr5.4%
Final simplification5.4%
(FPCore (x) :precision binary64 (- (/ PI 2.0) (* 2.0 (asin (/ 1.0 (sqrt 2.0))))))
double code(double x) {
return (((double) M_PI) / 2.0) - (2.0 * asin((1.0 / sqrt(2.0))));
}
public static double code(double x) {
return (Math.PI / 2.0) - (2.0 * Math.asin((1.0 / Math.sqrt(2.0))));
}
def code(x): return (math.pi / 2.0) - (2.0 * math.asin((1.0 / math.sqrt(2.0))))
function code(x) return Float64(Float64(pi / 2.0) - Float64(2.0 * asin(Float64(1.0 / sqrt(2.0))))) end
function tmp = code(x) tmp = (pi / 2.0) - (2.0 * asin((1.0 / sqrt(2.0)))); end
code[x_] := N[(N[(Pi / 2.0), $MachinePrecision] - N[(2.0 * N[ArcSin[N[(1.0 / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\pi}{2} - 2 \cdot \sin^{-1} \left(\frac{1}{\sqrt{2}}\right)
\end{array}
Initial program 5.3%
clear-num5.3%
sqrt-div5.6%
metadata-eval5.6%
Applied egg-rr5.6%
Taylor expanded in x around 0 4.1%
Final simplification4.1%
(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 5.3%
Taylor expanded in x around 0 3.8%
Final simplification3.8%
(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 2024084
(FPCore (x)
:name "Ian Simplification"
:precision binary64
:alt
(asin x)
(- (/ PI 2.0) (* 2.0 (asin (sqrt (/ (- 1.0 x) 2.0))))))