
(FPCore (x) :precision binary64 (acos (- 1.0 x)))
double code(double x) {
return acos((1.0 - x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = acos((1.0d0 - x))
end function
public static double code(double x) {
return Math.acos((1.0 - x));
}
def code(x): return math.acos((1.0 - x))
function code(x) return acos(Float64(1.0 - x)) end
function tmp = code(x) tmp = acos((1.0 - x)); end
code[x_] := N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(1 - x\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 12 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (acos (- 1.0 x)))
double code(double x) {
return acos((1.0 - x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = acos((1.0d0 - x))
end function
public static double code(double x) {
return Math.acos((1.0 - x));
}
def code(x): return math.acos((1.0 - x))
function code(x) return acos(Float64(1.0 - x)) end
function tmp = code(x) tmp = acos((1.0 - x)); end
code[x_] := N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(1 - x\right)
\end{array}
(FPCore (x)
:precision binary64
(let* ((t_0 (* 0.5 (PI)))
(t_1 (acos (- 1.0 x)))
(t_2 (cbrt (PI)))
(t_3 (- t_1 t_0))
(t_4 (fma (* 0.25 (PI)) (PI) (pow t_1 2.0))))
(/
(/
(fma
(* (fma 0.125 (pow (PI) 3.0) (pow t_1 3.0)) (PI))
t_4
(*
(* (- (pow t_0 4.0) (pow t_1 4.0)) -2.0)
(fma t_1 t_3 (* (* (PI) (PI)) 0.25))))
(* (fma t_1 t_3 (* (* (pow (cbrt (pow (PI) 1.5)) 2.0) (PI)) 0.25)) t_4))
(fma (pow (cbrt (pow t_2 2.0)) 3.0) (pow (cbrt t_2) 3.0) (* 2.0 t_1)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := 0.5 \cdot \mathsf{PI}\left(\right)\\
t_1 := \cos^{-1} \left(1 - x\right)\\
t_2 := \sqrt[3]{\mathsf{PI}\left(\right)}\\
t_3 := t\_1 - t\_0\\
t_4 := \mathsf{fma}\left(0.25 \cdot \mathsf{PI}\left(\right), \mathsf{PI}\left(\right), {t\_1}^{2}\right)\\
\frac{\frac{\mathsf{fma}\left(\mathsf{fma}\left(0.125, {\mathsf{PI}\left(\right)}^{3}, {t\_1}^{3}\right) \cdot \mathsf{PI}\left(\right), t\_4, \left(\left({t\_0}^{4} - {t\_1}^{4}\right) \cdot -2\right) \cdot \mathsf{fma}\left(t\_1, t\_3, \left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25\right)\right)}{\mathsf{fma}\left(t\_1, t\_3, \left({\left(\sqrt[3]{{\mathsf{PI}\left(\right)}^{1.5}}\right)}^{2} \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25\right) \cdot t\_4}}{\mathsf{fma}\left({\left(\sqrt[3]{{t\_2}^{2}}\right)}^{3}, {\left(\sqrt[3]{t\_2}\right)}^{3}, 2 \cdot t\_1\right)}
\end{array}
\end{array}
Initial program 6.4%
lift-acos.f64N/A
acos-asinN/A
asin-acosN/A
lift-acos.f64N/A
flip--N/A
frac-subN/A
lower-/.f64N/A
Applied rewrites6.4%
Applied rewrites9.6%
lift-*.f64N/A
lift-fma.f64N/A
distribute-lft-inN/A
associate-*r*N/A
metadata-evalN/A
lift-PI.f64N/A
*-un-lft-identityN/A
add-cube-cbrtN/A
pow3N/A
add-cube-cbrtN/A
cbrt-prodN/A
cube-prodN/A
lower-fma.f64N/A
Applied rewrites9.6%
rem-cbrt-cubeN/A
sqr-powN/A
cbrt-prodN/A
pow2N/A
lower-pow.f64N/A
lower-cbrt.f64N/A
lower-pow.f64N/A
metadata-eval9.6
Applied rewrites9.6%
Final simplification9.6%
(FPCore (x)
:precision binary64
(let* ((t_0 (pow (PI) 3.0))
(t_1 (* 0.5 (PI)))
(t_2 (cbrt (PI)))
(t_3 (acos (- 1.0 x)))
(t_4 (- t_3 t_1))
(t_5 (fma (* 0.25 (PI)) (PI) (pow t_3 2.0))))
(/
(/
(fma
(* (fma 0.125 t_0 (pow t_3 3.0)) (PI))
t_5
(*
(* (- (pow t_1 4.0) (pow t_3 4.0)) -2.0)
(fma t_3 t_4 (* (* (PI) (PI)) 0.25))))
(* (fma t_3 t_4 (* (* (cbrt t_0) (PI)) 0.25)) t_5))
(fma (pow (cbrt (pow t_2 2.0)) 3.0) (pow (cbrt t_2) 3.0) (* 2.0 t_3)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := {\mathsf{PI}\left(\right)}^{3}\\
t_1 := 0.5 \cdot \mathsf{PI}\left(\right)\\
t_2 := \sqrt[3]{\mathsf{PI}\left(\right)}\\
t_3 := \cos^{-1} \left(1 - x\right)\\
t_4 := t\_3 - t\_1\\
t_5 := \mathsf{fma}\left(0.25 \cdot \mathsf{PI}\left(\right), \mathsf{PI}\left(\right), {t\_3}^{2}\right)\\
\frac{\frac{\mathsf{fma}\left(\mathsf{fma}\left(0.125, t\_0, {t\_3}^{3}\right) \cdot \mathsf{PI}\left(\right), t\_5, \left(\left({t\_1}^{4} - {t\_3}^{4}\right) \cdot -2\right) \cdot \mathsf{fma}\left(t\_3, t\_4, \left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25\right)\right)}{\mathsf{fma}\left(t\_3, t\_4, \left(\sqrt[3]{t\_0} \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25\right) \cdot t\_5}}{\mathsf{fma}\left({\left(\sqrt[3]{{t\_2}^{2}}\right)}^{3}, {\left(\sqrt[3]{t\_2}\right)}^{3}, 2 \cdot t\_3\right)}
\end{array}
\end{array}
Initial program 6.4%
lift-acos.f64N/A
acos-asinN/A
asin-acosN/A
lift-acos.f64N/A
flip--N/A
frac-subN/A
lower-/.f64N/A
Applied rewrites6.4%
Applied rewrites9.6%
lift-*.f64N/A
lift-fma.f64N/A
distribute-lft-inN/A
associate-*r*N/A
metadata-evalN/A
lift-PI.f64N/A
*-un-lft-identityN/A
add-cube-cbrtN/A
pow3N/A
add-cube-cbrtN/A
cbrt-prodN/A
cube-prodN/A
lower-fma.f64N/A
Applied rewrites9.6%
rem-cbrt-cubeN/A
lift-pow.f64N/A
lower-cbrt.f649.6
Applied rewrites9.6%
Final simplification9.6%
(FPCore (x)
:precision binary64
(let* ((t_0 (cbrt (PI)))
(t_1 (* 0.5 (PI)))
(t_2 (acos (- 1.0 x)))
(t_3 (fma t_2 (- t_2 t_1) (* (* (PI) (PI)) 0.25)))
(t_4 (fma (* 0.25 (PI)) (PI) (pow t_2 2.0))))
(/
(/
(fma
(* (fma 0.125 (pow (PI) 3.0) (pow t_2 3.0)) (PI))
t_4
(* (* (- (pow t_1 4.0) (pow t_2 4.0)) -2.0) t_3))
(* t_3 t_4))
(fma (pow (cbrt (pow t_0 2.0)) 3.0) (pow (cbrt t_0) 3.0) (* 2.0 t_2)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt[3]{\mathsf{PI}\left(\right)}\\
t_1 := 0.5 \cdot \mathsf{PI}\left(\right)\\
t_2 := \cos^{-1} \left(1 - x\right)\\
t_3 := \mathsf{fma}\left(t\_2, t\_2 - t\_1, \left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25\right)\\
t_4 := \mathsf{fma}\left(0.25 \cdot \mathsf{PI}\left(\right), \mathsf{PI}\left(\right), {t\_2}^{2}\right)\\
\frac{\frac{\mathsf{fma}\left(\mathsf{fma}\left(0.125, {\mathsf{PI}\left(\right)}^{3}, {t\_2}^{3}\right) \cdot \mathsf{PI}\left(\right), t\_4, \left(\left({t\_1}^{4} - {t\_2}^{4}\right) \cdot -2\right) \cdot t\_3\right)}{t\_3 \cdot t\_4}}{\mathsf{fma}\left({\left(\sqrt[3]{{t\_0}^{2}}\right)}^{3}, {\left(\sqrt[3]{t\_0}\right)}^{3}, 2 \cdot t\_2\right)}
\end{array}
\end{array}
Initial program 6.4%
lift-acos.f64N/A
acos-asinN/A
asin-acosN/A
lift-acos.f64N/A
flip--N/A
frac-subN/A
lower-/.f64N/A
Applied rewrites6.4%
Applied rewrites9.6%
lift-*.f64N/A
lift-fma.f64N/A
distribute-lft-inN/A
associate-*r*N/A
metadata-evalN/A
lift-PI.f64N/A
*-un-lft-identityN/A
add-cube-cbrtN/A
pow3N/A
add-cube-cbrtN/A
cbrt-prodN/A
cube-prodN/A
lower-fma.f64N/A
Applied rewrites9.6%
Final simplification9.6%
(FPCore (x)
:precision binary64
(let* ((t_0 (cbrt (pow (PI) 1.5)))
(t_1 (* 0.5 (PI)))
(t_2 (acos (- 1.0 x)))
(t_3 (fma t_2 (- t_2 t_1) (* (* (PI) (PI)) 0.25)))
(t_4 (fma (* 0.25 (PI)) (PI) (pow t_2 2.0))))
(/
(/
(fma
(* (fma 0.125 (pow (PI) 3.0) (pow t_2 3.0)) (PI))
t_4
(* (* (- (pow t_1 4.0) (pow t_2 4.0)) -2.0) t_3))
(* t_3 t_4))
(fma t_0 t_0 (* 2.0 t_2)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt[3]{{\mathsf{PI}\left(\right)}^{1.5}}\\
t_1 := 0.5 \cdot \mathsf{PI}\left(\right)\\
t_2 := \cos^{-1} \left(1 - x\right)\\
t_3 := \mathsf{fma}\left(t\_2, t\_2 - t\_1, \left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25\right)\\
t_4 := \mathsf{fma}\left(0.25 \cdot \mathsf{PI}\left(\right), \mathsf{PI}\left(\right), {t\_2}^{2}\right)\\
\frac{\frac{\mathsf{fma}\left(\mathsf{fma}\left(0.125, {\mathsf{PI}\left(\right)}^{3}, {t\_2}^{3}\right) \cdot \mathsf{PI}\left(\right), t\_4, \left(\left({t\_1}^{4} - {t\_2}^{4}\right) \cdot -2\right) \cdot t\_3\right)}{t\_3 \cdot t\_4}}{\mathsf{fma}\left(t\_0, t\_0, 2 \cdot t\_2\right)}
\end{array}
\end{array}
Initial program 6.4%
lift-acos.f64N/A
acos-asinN/A
asin-acosN/A
lift-acos.f64N/A
flip--N/A
frac-subN/A
lower-/.f64N/A
Applied rewrites6.4%
Applied rewrites9.6%
lift-*.f64N/A
lift-fma.f64N/A
distribute-lft-inN/A
associate-*r*N/A
metadata-evalN/A
lift-PI.f64N/A
*-un-lft-identityN/A
add-cube-cbrtN/A
pow3N/A
add-cube-cbrtN/A
cbrt-prodN/A
cube-prodN/A
lower-fma.f64N/A
Applied rewrites9.6%
lift-fma.f64N/A
Applied rewrites9.6%
Final simplification9.6%
(FPCore (x)
:precision binary64
(let* ((t_0 (pow (PI) 3.0))
(t_1 (* 0.5 (PI)))
(t_2 (acos (- 1.0 x)))
(t_3 (- t_2 t_1))
(t_4 (fma (* 0.25 (PI)) (PI) (pow t_2 2.0))))
(/
(/
(fma
(* (fma 0.125 t_0 (pow t_2 3.0)) (PI))
t_4
(*
(* (- (pow t_1 4.0) (pow t_2 4.0)) -2.0)
(fma t_2 t_3 (* (* (PI) (PI)) 0.25))))
(* (fma t_2 t_3 (* (* (cbrt t_0) (PI)) 0.25)) t_4))
(* (fma 0.5 (PI) t_2) 2.0))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := {\mathsf{PI}\left(\right)}^{3}\\
t_1 := 0.5 \cdot \mathsf{PI}\left(\right)\\
t_2 := \cos^{-1} \left(1 - x\right)\\
t_3 := t\_2 - t\_1\\
t_4 := \mathsf{fma}\left(0.25 \cdot \mathsf{PI}\left(\right), \mathsf{PI}\left(\right), {t\_2}^{2}\right)\\
\frac{\frac{\mathsf{fma}\left(\mathsf{fma}\left(0.125, t\_0, {t\_2}^{3}\right) \cdot \mathsf{PI}\left(\right), t\_4, \left(\left({t\_1}^{4} - {t\_2}^{4}\right) \cdot -2\right) \cdot \mathsf{fma}\left(t\_2, t\_3, \left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25\right)\right)}{\mathsf{fma}\left(t\_2, t\_3, \left(\sqrt[3]{t\_0} \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25\right) \cdot t\_4}}{\mathsf{fma}\left(0.5, \mathsf{PI}\left(\right), t\_2\right) \cdot 2}
\end{array}
\end{array}
Initial program 6.4%
lift-acos.f64N/A
acos-asinN/A
asin-acosN/A
lift-acos.f64N/A
flip--N/A
frac-subN/A
lower-/.f64N/A
Applied rewrites6.4%
Applied rewrites9.6%
rem-cbrt-cubeN/A
lift-pow.f64N/A
lower-cbrt.f649.6
Applied rewrites9.6%
Final simplification9.6%
(FPCore (x)
:precision binary64
(let* ((t_0 (* (PI) (PI)))
(t_1 (* 0.5 (PI)))
(t_2 (acos (- 1.0 x)))
(t_3 (fma (* 0.25 (PI)) (PI) (pow t_2 2.0)))
(t_4 (fma t_2 (- t_2 t_1) (* t_0 0.25))))
(/
(/
(fma
(* (fma 0.125 (* t_0 (PI)) (pow t_2 3.0)) (PI))
t_3
(* (* (- (pow t_1 4.0) (pow t_2 4.0)) -2.0) t_4))
(* t_4 t_3))
(* (fma 0.5 (PI) t_2) 2.0))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\\
t_1 := 0.5 \cdot \mathsf{PI}\left(\right)\\
t_2 := \cos^{-1} \left(1 - x\right)\\
t_3 := \mathsf{fma}\left(0.25 \cdot \mathsf{PI}\left(\right), \mathsf{PI}\left(\right), {t\_2}^{2}\right)\\
t_4 := \mathsf{fma}\left(t\_2, t\_2 - t\_1, t\_0 \cdot 0.25\right)\\
\frac{\frac{\mathsf{fma}\left(\mathsf{fma}\left(0.125, t\_0 \cdot \mathsf{PI}\left(\right), {t\_2}^{3}\right) \cdot \mathsf{PI}\left(\right), t\_3, \left(\left({t\_1}^{4} - {t\_2}^{4}\right) \cdot -2\right) \cdot t\_4\right)}{t\_4 \cdot t\_3}}{\mathsf{fma}\left(0.5, \mathsf{PI}\left(\right), t\_2\right) \cdot 2}
\end{array}
\end{array}
Initial program 6.4%
lift-acos.f64N/A
acos-asinN/A
asin-acosN/A
lift-acos.f64N/A
flip--N/A
frac-subN/A
lower-/.f64N/A
Applied rewrites6.4%
Applied rewrites9.6%
lift-pow.f64N/A
unpow3N/A
lift-*.f64N/A
lower-*.f649.6
Applied rewrites9.6%
Final simplification9.6%
(FPCore (x) :precision binary64 (let* ((t_0 (fma (PI) 0.5 (acos (- 1.0 x))))) (fma (* t_0 (PI)) (/ 0.5 t_0) (- (asin (- 1.0 x))))))
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(\mathsf{PI}\left(\right), 0.5, \cos^{-1} \left(1 - x\right)\right)\\
\mathsf{fma}\left(t\_0 \cdot \mathsf{PI}\left(\right), \frac{0.5}{t\_0}, -\sin^{-1} \left(1 - x\right)\right)
\end{array}
\end{array}
Initial program 6.4%
lift-acos.f64N/A
acos-asinN/A
flip--N/A
clear-numN/A
lower-/.f64N/A
lower-/.f64N/A
clear-numN/A
associate-/r/N/A
lower-fma.f64N/A
metadata-evalN/A
lower-PI.f64N/A
lower-asin.f64N/A
difference-of-squaresN/A
acos-asinN/A
lift-acos.f64N/A
Applied rewrites6.4%
Applied rewrites9.6%
Final simplification9.6%
(FPCore (x) :precision binary64 (fma (/ 2.0 (PI)) (* (* (PI) (PI)) 0.25) (- (asin (- 1.0 x)))))
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{2}{\mathsf{PI}\left(\right)}, \left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot 0.25, -\sin^{-1} \left(1 - x\right)\right)
\end{array}
Initial program 6.4%
lift-acos.f64N/A
acos-asinN/A
sub-negN/A
div-invN/A
lower-fma.f64N/A
lower-PI.f64N/A
metadata-evalN/A
lower-neg.f64N/A
lower-asin.f646.4
Applied rewrites6.4%
lift-fma.f64N/A
lift-*.f64N/A
unpow1N/A
metadata-evalN/A
pow-prod-upN/A
inv-powN/A
lift-*.f64N/A
metadata-evalN/A
div-invN/A
clear-numN/A
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
unpow-prod-downN/A
metadata-evalN/A
pow2N/A
associate-*r*N/A
lift-*.f64N/A
lower-fma.f64N/A
Applied rewrites9.6%
(FPCore (x) :precision binary64 (if (<= x 5.5e-17) (acos (- x)) (fma (PI) 0.5 (- (asin (- 1.0 x))))))
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 5.5 \cdot 10^{-17}:\\
\;\;\;\;\cos^{-1} \left(-x\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{PI}\left(\right), 0.5, -\sin^{-1} \left(1 - x\right)\right)\\
\end{array}
\end{array}
if x < 5.50000000000000001e-17Initial program 3.9%
Taylor expanded in x around inf
mul-1-negN/A
lower-neg.f646.4
Applied rewrites6.4%
if 5.50000000000000001e-17 < x Initial program 53.9%
lift-acos.f64N/A
acos-asinN/A
sub-negN/A
div-invN/A
lower-fma.f64N/A
lower-PI.f64N/A
metadata-evalN/A
lower-neg.f64N/A
lower-asin.f6454.0
Applied rewrites54.0%
(FPCore (x) :precision binary64 (if (<= x 5.5e-17) (acos (- x)) (acos (- 1.0 x))))
double code(double x) {
double tmp;
if (x <= 5.5e-17) {
tmp = acos(-x);
} else {
tmp = acos((1.0 - x));
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 5.5d-17) then
tmp = acos(-x)
else
tmp = acos((1.0d0 - x))
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 5.5e-17) {
tmp = Math.acos(-x);
} else {
tmp = Math.acos((1.0 - x));
}
return tmp;
}
def code(x): tmp = 0 if x <= 5.5e-17: tmp = math.acos(-x) else: tmp = math.acos((1.0 - x)) return tmp
function code(x) tmp = 0.0 if (x <= 5.5e-17) tmp = acos(Float64(-x)); else tmp = acos(Float64(1.0 - x)); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 5.5e-17) tmp = acos(-x); else tmp = acos((1.0 - x)); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 5.5e-17], N[ArcCos[(-x)], $MachinePrecision], N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 5.5 \cdot 10^{-17}:\\
\;\;\;\;\cos^{-1} \left(-x\right)\\
\mathbf{else}:\\
\;\;\;\;\cos^{-1} \left(1 - x\right)\\
\end{array}
\end{array}
if x < 5.50000000000000001e-17Initial program 3.9%
Taylor expanded in x around inf
mul-1-negN/A
lower-neg.f646.4
Applied rewrites6.4%
if 5.50000000000000001e-17 < x Initial program 53.9%
(FPCore (x) :precision binary64 (acos (- x)))
double code(double x) {
return acos(-x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = acos(-x)
end function
public static double code(double x) {
return Math.acos(-x);
}
def code(x): return math.acos(-x)
function code(x) return acos(Float64(-x)) end
function tmp = code(x) tmp = acos(-x); end
code[x_] := N[ArcCos[(-x)], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(-x\right)
\end{array}
Initial program 6.4%
Taylor expanded in x around inf
mul-1-negN/A
lower-neg.f646.8
Applied rewrites6.8%
(FPCore (x) :precision binary64 (acos 1.0))
double code(double x) {
return acos(1.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = acos(1.0d0)
end function
public static double code(double x) {
return Math.acos(1.0);
}
def code(x): return math.acos(1.0)
function code(x) return acos(1.0) end
function tmp = code(x) tmp = acos(1.0); end
code[x_] := N[ArcCos[1.0], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} 1
\end{array}
Initial program 6.4%
Taylor expanded in x around 0
Applied rewrites3.8%
(FPCore (x) :precision binary64 (* 2.0 (asin (sqrt (/ x 2.0)))))
double code(double x) {
return 2.0 * asin(sqrt((x / 2.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 * asin(sqrt((x / 2.0d0)))
end function
public static double code(double x) {
return 2.0 * Math.asin(Math.sqrt((x / 2.0)));
}
def code(x): return 2.0 * math.asin(math.sqrt((x / 2.0)))
function code(x) return Float64(2.0 * asin(sqrt(Float64(x / 2.0)))) end
function tmp = code(x) tmp = 2.0 * asin(sqrt((x / 2.0))); end
code[x_] := N[(2.0 * N[ArcSin[N[Sqrt[N[(x / 2.0), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \sin^{-1} \left(\sqrt{\frac{x}{2}}\right)
\end{array}
herbie shell --seed 2024332
(FPCore (x)
:name "bug323 (missed optimization)"
:precision binary64
:pre (and (<= 0.0 x) (<= x 0.5))
:alt
(! :herbie-platform default (* 2 (asin (sqrt (/ x 2)))))
(acos (- 1.0 x)))