
(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
(let* ((t_0 (cbrt (pow PI 1.5))))
(/
(+ (* 0.25 (* PI PI)) (* (pow (acos (sqrt (+ 0.5 (* -0.5 x)))) 2.0) -4.0))
(-
(- (/ PI 2.0) (* t_0 t_0))
(* 2.0 (acos (pow (+ 0.5 (/ x -2.0)) 0.5)))))))
double code(double x) {
double t_0 = cbrt(pow(((double) M_PI), 1.5));
return ((0.25 * (((double) M_PI) * ((double) M_PI))) + (pow(acos(sqrt((0.5 + (-0.5 * x)))), 2.0) * -4.0)) / (((((double) M_PI) / 2.0) - (t_0 * t_0)) - (2.0 * acos(pow((0.5 + (x / -2.0)), 0.5))));
}
public static double code(double x) {
double t_0 = Math.cbrt(Math.pow(Math.PI, 1.5));
return ((0.25 * (Math.PI * Math.PI)) + (Math.pow(Math.acos(Math.sqrt((0.5 + (-0.5 * x)))), 2.0) * -4.0)) / (((Math.PI / 2.0) - (t_0 * t_0)) - (2.0 * Math.acos(Math.pow((0.5 + (x / -2.0)), 0.5))));
}
function code(x) t_0 = cbrt((pi ^ 1.5)) return Float64(Float64(Float64(0.25 * Float64(pi * pi)) + Float64((acos(sqrt(Float64(0.5 + Float64(-0.5 * x)))) ^ 2.0) * -4.0)) / Float64(Float64(Float64(pi / 2.0) - Float64(t_0 * t_0)) - Float64(2.0 * acos((Float64(0.5 + Float64(x / -2.0)) ^ 0.5))))) end
code[x_] := Block[{t$95$0 = N[Power[N[Power[Pi, 1.5], $MachinePrecision], 1/3], $MachinePrecision]}, N[(N[(N[(0.25 * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision] + N[(N[Power[N[ArcCos[N[Sqrt[N[(0.5 + N[(-0.5 * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision] * -4.0), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(Pi / 2.0), $MachinePrecision] - N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision] - N[(2.0 * N[ArcCos[N[Power[N[(0.5 + N[(x / -2.0), $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt[3]{{\pi}^{1.5}}\\
\frac{0.25 \cdot \left(\pi \cdot \pi\right) + {\cos^{-1} \left(\sqrt{0.5 + -0.5 \cdot x}\right)}^{2} \cdot -4}{\left(\frac{\pi}{2} - t\_0 \cdot t\_0\right) - 2 \cdot \cos^{-1} \left({\left(0.5 + \frac{x}{-2}\right)}^{0.5}\right)}
\end{array}
\end{array}
Initial program 6.2%
asin-acosN/A
sub-negN/A
distribute-rgt-inN/A
div-invN/A
metadata-evalN/A
associate-*l*N/A
metadata-evalN/A
*-rgt-identityN/A
+-lowering-+.f64N/A
PI-lowering-PI.f64N/A
*-lowering-*.f64N/A
Applied egg-rr7.6%
associate--r+N/A
flip--N/A
/-lowering-/.f64N/A
Applied egg-rr7.6%
rem-cbrt-cubeN/A
add-sqr-sqrtN/A
unpow-prod-downN/A
cbrt-prodN/A
*-lowering-*.f64N/A
cbrt-lowering-cbrt.f64N/A
pow1/2N/A
pow-powN/A
metadata-evalN/A
metadata-evalN/A
pow-lowering-pow.f64N/A
PI-lowering-PI.f64N/A
metadata-evalN/A
cbrt-lowering-cbrt.f64N/A
pow1/2N/A
pow-powN/A
metadata-evalN/A
metadata-evalN/A
pow-lowering-pow.f64N/A
PI-lowering-PI.f64N/A
metadata-eval7.7%
Applied egg-rr7.7%
Taylor expanded in x around 0
cancel-sign-sub-invN/A
metadata-evalN/A
cancel-sign-sub-invN/A
distribute-lft-neg-inN/A
+-lowering-+.f64N/A
Simplified7.7%
Final simplification7.7%
(FPCore (x)
:precision binary64
(let* ((t_0 (- (/ PI 2.0) PI)) (t_1 (acos (pow (+ 0.5 (/ x -2.0)) 0.5))))
(/
(- (* t_0 t_0) (* 4.0 (pow t_1 2.0)))
(- (- (/ PI 2.0) (* (pow PI 0.25) (cbrt (pow PI 2.25)))) (* 2.0 t_1)))))
double code(double x) {
double t_0 = (((double) M_PI) / 2.0) - ((double) M_PI);
double t_1 = acos(pow((0.5 + (x / -2.0)), 0.5));
return ((t_0 * t_0) - (4.0 * pow(t_1, 2.0))) / (((((double) M_PI) / 2.0) - (pow(((double) M_PI), 0.25) * cbrt(pow(((double) M_PI), 2.25)))) - (2.0 * t_1));
}
public static double code(double x) {
double t_0 = (Math.PI / 2.0) - Math.PI;
double t_1 = Math.acos(Math.pow((0.5 + (x / -2.0)), 0.5));
return ((t_0 * t_0) - (4.0 * Math.pow(t_1, 2.0))) / (((Math.PI / 2.0) - (Math.pow(Math.PI, 0.25) * Math.cbrt(Math.pow(Math.PI, 2.25)))) - (2.0 * t_1));
}
function code(x) t_0 = Float64(Float64(pi / 2.0) - pi) t_1 = acos((Float64(0.5 + Float64(x / -2.0)) ^ 0.5)) return Float64(Float64(Float64(t_0 * t_0) - Float64(4.0 * (t_1 ^ 2.0))) / Float64(Float64(Float64(pi / 2.0) - Float64((pi ^ 0.25) * cbrt((pi ^ 2.25)))) - Float64(2.0 * t_1))) end
code[x_] := Block[{t$95$0 = N[(N[(Pi / 2.0), $MachinePrecision] - Pi), $MachinePrecision]}, Block[{t$95$1 = N[ArcCos[N[Power[N[(0.5 + N[(x / -2.0), $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] - N[(4.0 * N[Power[t$95$1, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(Pi / 2.0), $MachinePrecision] - N[(N[Power[Pi, 0.25], $MachinePrecision] * N[Power[N[Power[Pi, 2.25], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(2.0 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\pi}{2} - \pi\\
t_1 := \cos^{-1} \left({\left(0.5 + \frac{x}{-2}\right)}^{0.5}\right)\\
\frac{t\_0 \cdot t\_0 - 4 \cdot {t\_1}^{2}}{\left(\frac{\pi}{2} - {\pi}^{0.25} \cdot \sqrt[3]{{\pi}^{2.25}}\right) - 2 \cdot t\_1}
\end{array}
\end{array}
Initial program 6.2%
asin-acosN/A
sub-negN/A
distribute-rgt-inN/A
div-invN/A
metadata-evalN/A
associate-*l*N/A
metadata-evalN/A
*-rgt-identityN/A
+-lowering-+.f64N/A
PI-lowering-PI.f64N/A
*-lowering-*.f64N/A
Applied egg-rr7.6%
associate--r+N/A
flip--N/A
/-lowering-/.f64N/A
Applied egg-rr7.6%
rem-cbrt-cubeN/A
add-sqr-sqrtN/A
unpow-prod-downN/A
cbrt-prodN/A
*-lowering-*.f64N/A
cbrt-lowering-cbrt.f64N/A
pow1/2N/A
pow-powN/A
metadata-evalN/A
metadata-evalN/A
pow-lowering-pow.f64N/A
PI-lowering-PI.f64N/A
metadata-evalN/A
cbrt-lowering-cbrt.f64N/A
pow1/2N/A
pow-powN/A
metadata-evalN/A
metadata-evalN/A
pow-lowering-pow.f64N/A
PI-lowering-PI.f64N/A
metadata-eval7.7%
Applied egg-rr7.7%
cbrt-unprodN/A
sqr-powN/A
associate-*l*N/A
sqr-powN/A
cube-unmultN/A
pow3N/A
sqr-powN/A
cbrt-prodN/A
Applied egg-rr7.6%
Final simplification7.6%
(FPCore (x)
:precision binary64
(let* ((t_0 (- (/ PI 2.0) PI)) (t_1 (acos (pow (+ 0.5 (/ x -2.0)) 0.5))))
(/
(- (* t_0 t_0) (* 4.0 (pow t_1 2.0)))
(- (- (/ PI 2.0) (cbrt (* PI (* PI PI)))) (* 2.0 t_1)))))
double code(double x) {
double t_0 = (((double) M_PI) / 2.0) - ((double) M_PI);
double t_1 = acos(pow((0.5 + (x / -2.0)), 0.5));
return ((t_0 * t_0) - (4.0 * pow(t_1, 2.0))) / (((((double) M_PI) / 2.0) - cbrt((((double) M_PI) * (((double) M_PI) * ((double) M_PI))))) - (2.0 * t_1));
}
public static double code(double x) {
double t_0 = (Math.PI / 2.0) - Math.PI;
double t_1 = Math.acos(Math.pow((0.5 + (x / -2.0)), 0.5));
return ((t_0 * t_0) - (4.0 * Math.pow(t_1, 2.0))) / (((Math.PI / 2.0) - Math.cbrt((Math.PI * (Math.PI * Math.PI)))) - (2.0 * t_1));
}
function code(x) t_0 = Float64(Float64(pi / 2.0) - pi) t_1 = acos((Float64(0.5 + Float64(x / -2.0)) ^ 0.5)) return Float64(Float64(Float64(t_0 * t_0) - Float64(4.0 * (t_1 ^ 2.0))) / Float64(Float64(Float64(pi / 2.0) - cbrt(Float64(pi * Float64(pi * pi)))) - Float64(2.0 * t_1))) end
code[x_] := Block[{t$95$0 = N[(N[(Pi / 2.0), $MachinePrecision] - Pi), $MachinePrecision]}, Block[{t$95$1 = N[ArcCos[N[Power[N[(0.5 + N[(x / -2.0), $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] - N[(4.0 * N[Power[t$95$1, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(Pi / 2.0), $MachinePrecision] - N[Power[N[(Pi * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] - N[(2.0 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\pi}{2} - \pi\\
t_1 := \cos^{-1} \left({\left(0.5 + \frac{x}{-2}\right)}^{0.5}\right)\\
\frac{t\_0 \cdot t\_0 - 4 \cdot {t\_1}^{2}}{\left(\frac{\pi}{2} - \sqrt[3]{\pi \cdot \left(\pi \cdot \pi\right)}\right) - 2 \cdot t\_1}
\end{array}
\end{array}
Initial program 6.2%
asin-acosN/A
sub-negN/A
distribute-rgt-inN/A
div-invN/A
metadata-evalN/A
associate-*l*N/A
metadata-evalN/A
*-rgt-identityN/A
+-lowering-+.f64N/A
PI-lowering-PI.f64N/A
*-lowering-*.f64N/A
Applied egg-rr7.6%
associate--r+N/A
flip--N/A
/-lowering-/.f64N/A
Applied egg-rr7.6%
add-cbrt-cubeN/A
associate-*r*N/A
cbrt-lowering-cbrt.f64N/A
*-lowering-*.f64N/A
PI-lowering-PI.f64N/A
*-lowering-*.f64N/A
PI-lowering-PI.f64N/A
PI-lowering-PI.f647.6%
Applied egg-rr7.6%
Final simplification7.6%
(FPCore (x)
:precision binary64
(let* ((t_0 (acos (sqrt (+ 0.5 (* -0.5 x))))))
(/
(+ (* 0.25 (* PI PI)) (* (pow t_0 2.0) -4.0))
(+ (* t_0 -2.0) (* PI -0.5)))))
double code(double x) {
double t_0 = acos(sqrt((0.5 + (-0.5 * x))));
return ((0.25 * (((double) M_PI) * ((double) M_PI))) + (pow(t_0, 2.0) * -4.0)) / ((t_0 * -2.0) + (((double) M_PI) * -0.5));
}
public static double code(double x) {
double t_0 = Math.acos(Math.sqrt((0.5 + (-0.5 * x))));
return ((0.25 * (Math.PI * Math.PI)) + (Math.pow(t_0, 2.0) * -4.0)) / ((t_0 * -2.0) + (Math.PI * -0.5));
}
def code(x): t_0 = math.acos(math.sqrt((0.5 + (-0.5 * x)))) return ((0.25 * (math.pi * math.pi)) + (math.pow(t_0, 2.0) * -4.0)) / ((t_0 * -2.0) + (math.pi * -0.5))
function code(x) t_0 = acos(sqrt(Float64(0.5 + Float64(-0.5 * x)))) return Float64(Float64(Float64(0.25 * Float64(pi * pi)) + Float64((t_0 ^ 2.0) * -4.0)) / Float64(Float64(t_0 * -2.0) + Float64(pi * -0.5))) end
function tmp = code(x) t_0 = acos(sqrt((0.5 + (-0.5 * x)))); tmp = ((0.25 * (pi * pi)) + ((t_0 ^ 2.0) * -4.0)) / ((t_0 * -2.0) + (pi * -0.5)); end
code[x_] := Block[{t$95$0 = N[ArcCos[N[Sqrt[N[(0.5 + N[(-0.5 * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(0.25 * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision] + N[(N[Power[t$95$0, 2.0], $MachinePrecision] * -4.0), $MachinePrecision]), $MachinePrecision] / N[(N[(t$95$0 * -2.0), $MachinePrecision] + N[(Pi * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos^{-1} \left(\sqrt{0.5 + -0.5 \cdot x}\right)\\
\frac{0.25 \cdot \left(\pi \cdot \pi\right) + {t\_0}^{2} \cdot -4}{t\_0 \cdot -2 + \pi \cdot -0.5}
\end{array}
\end{array}
Initial program 6.2%
asin-acosN/A
sub-negN/A
distribute-rgt-inN/A
div-invN/A
metadata-evalN/A
associate-*l*N/A
metadata-evalN/A
*-rgt-identityN/A
+-lowering-+.f64N/A
PI-lowering-PI.f64N/A
*-lowering-*.f64N/A
Applied egg-rr7.6%
associate--r+N/A
flip--N/A
/-lowering-/.f64N/A
Applied egg-rr7.6%
Taylor expanded in x around 0
Simplified7.6%
Final simplification7.6%
(FPCore (x) :precision binary64 (+ (* PI -0.5) (* 2.0 (acos (sqrt (* 0.5 (- 1.0 x)))))))
double code(double x) {
return (((double) M_PI) * -0.5) + (2.0 * acos(sqrt((0.5 * (1.0 - x)))));
}
public static double code(double x) {
return (Math.PI * -0.5) + (2.0 * Math.acos(Math.sqrt((0.5 * (1.0 - x)))));
}
def code(x): return (math.pi * -0.5) + (2.0 * math.acos(math.sqrt((0.5 * (1.0 - x)))))
function code(x) return Float64(Float64(pi * -0.5) + Float64(2.0 * acos(sqrt(Float64(0.5 * Float64(1.0 - x)))))) end
function tmp = code(x) tmp = (pi * -0.5) + (2.0 * acos(sqrt((0.5 * (1.0 - x))))); end
code[x_] := N[(N[(Pi * -0.5), $MachinePrecision] + N[(2.0 * N[ArcCos[N[Sqrt[N[(0.5 * N[(1.0 - x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\pi \cdot -0.5 + 2 \cdot \cos^{-1} \left(\sqrt{0.5 \cdot \left(1 - x\right)}\right)
\end{array}
Initial program 6.2%
asin-acosN/A
sub-negN/A
distribute-rgt-inN/A
div-invN/A
metadata-evalN/A
associate-*l*N/A
metadata-evalN/A
*-rgt-identityN/A
+-lowering-+.f64N/A
PI-lowering-PI.f64N/A
*-lowering-*.f64N/A
Applied egg-rr7.6%
Taylor expanded in x around 0
associate--r+N/A
metadata-evalN/A
cancel-sign-sub-invN/A
sub-negN/A
+-lowering-+.f64N/A
sub-negN/A
neg-mul-1N/A
distribute-rgt-outN/A
metadata-evalN/A
metadata-evalN/A
distribute-rgt-neg-inN/A
*-commutativeN/A
distribute-lft-neg-inN/A
metadata-evalN/A
*-lowering-*.f64N/A
PI-lowering-PI.f64N/A
*-commutativeN/A
Simplified7.6%
Final simplification7.6%
(FPCore (x) :precision binary64 (+ (* PI -0.5) (* 2.0 (acos (sqrt 0.5)))))
double code(double x) {
return (((double) M_PI) * -0.5) + (2.0 * acos(sqrt(0.5)));
}
public static double code(double x) {
return (Math.PI * -0.5) + (2.0 * Math.acos(Math.sqrt(0.5)));
}
def code(x): return (math.pi * -0.5) + (2.0 * math.acos(math.sqrt(0.5)))
function code(x) return Float64(Float64(pi * -0.5) + Float64(2.0 * acos(sqrt(0.5)))) end
function tmp = code(x) tmp = (pi * -0.5) + (2.0 * acos(sqrt(0.5))); end
code[x_] := N[(N[(Pi * -0.5), $MachinePrecision] + N[(2.0 * N[ArcCos[N[Sqrt[0.5], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\pi \cdot -0.5 + 2 \cdot \cos^{-1} \left(\sqrt{0.5}\right)
\end{array}
Initial program 6.2%
asin-acosN/A
sub-negN/A
distribute-rgt-inN/A
div-invN/A
metadata-evalN/A
associate-*l*N/A
metadata-evalN/A
*-rgt-identityN/A
+-lowering-+.f64N/A
PI-lowering-PI.f64N/A
*-lowering-*.f64N/A
Applied egg-rr7.6%
Taylor expanded in x around 0
associate--r+N/A
metadata-evalN/A
cancel-sign-sub-invN/A
sub-negN/A
+-lowering-+.f64N/A
sub-negN/A
neg-mul-1N/A
distribute-rgt-outN/A
metadata-evalN/A
metadata-evalN/A
distribute-rgt-neg-inN/A
*-commutativeN/A
distribute-lft-neg-inN/A
metadata-evalN/A
*-lowering-*.f64N/A
PI-lowering-PI.f64N/A
*-commutativeN/A
Simplified7.6%
Taylor expanded in x around 0
sqrt-lowering-sqrt.f645.4%
Simplified5.4%
Final simplification5.4%
(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 2024194
(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))))))