bug323 (missed optimization)

Percentage Accurate: 6.8% → 10.3%
Time: 11.9s
Alternatives: 13
Speedup: 1.0×

Specification

?
\[0 \leq x \land x \leq 0.5\]
\[\begin{array}{l} \\ \cos^{-1} \left(1 - x\right) \end{array} \]
(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:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 13 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 6.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \cos^{-1} \left(1 - x\right) \end{array} \]
(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}

Alternative 1: 10.3% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{\sin^{-1} \left(1 - x\right)}\\ \mathsf{fma}\left({\left(\sqrt[3]{{t_0}^{2}} \cdot \sqrt[3]{t_0}\right)}^{2}, -t_0, \pi \cdot 0.5\right) \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (cbrt (asin (- 1.0 x)))))
   (fma (pow (* (cbrt (pow t_0 2.0)) (cbrt t_0)) 2.0) (- t_0) (* PI 0.5))))
double code(double x) {
	double t_0 = cbrt(asin((1.0 - x)));
	return fma(pow((cbrt(pow(t_0, 2.0)) * cbrt(t_0)), 2.0), -t_0, (((double) M_PI) * 0.5));
}
function code(x)
	t_0 = cbrt(asin(Float64(1.0 - x)))
	return fma((Float64(cbrt((t_0 ^ 2.0)) * cbrt(t_0)) ^ 2.0), Float64(-t_0), Float64(pi * 0.5))
end
code[x_] := Block[{t$95$0 = N[Power[N[ArcSin[N[(1.0 - x), $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision]}, N[(N[Power[N[(N[Power[N[Power[t$95$0, 2.0], $MachinePrecision], 1/3], $MachinePrecision] * N[Power[t$95$0, 1/3], $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] * (-t$95$0) + N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt[3]{\sin^{-1} \left(1 - x\right)}\\
\mathsf{fma}\left({\left(\sqrt[3]{{t_0}^{2}} \cdot \sqrt[3]{t_0}\right)}^{2}, -t_0, \pi \cdot 0.5\right)
\end{array}
\end{array}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Step-by-step derivation
    1. add-cbrt-cube7.1%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
    2. pow1/37.1%

      \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
    3. pow37.1%

      \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
  3. Applied egg-rr7.1%

    \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
  4. Step-by-step derivation
    1. unpow1/37.1%

      \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
    2. rem-cbrt-cube7.1%

      \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
    3. acos-asin7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} - \sin^{-1} \left(1 - x\right)} \]
    4. div-inv7.1%

      \[\leadsto \color{blue}{\pi \cdot \frac{1}{2}} - \sin^{-1} \left(1 - x\right) \]
    5. metadata-eval7.1%

      \[\leadsto \pi \cdot \color{blue}{0.5} - \sin^{-1} \left(1 - x\right) \]
    6. sub-neg7.1%

      \[\leadsto \color{blue}{\pi \cdot 0.5 + \left(-\sin^{-1} \left(1 - x\right)\right)} \]
    7. +-commutative7.1%

      \[\leadsto \color{blue}{\left(-\sin^{-1} \left(1 - x\right)\right) + \pi \cdot 0.5} \]
    8. add-cube-cbrt10.7%

      \[\leadsto \left(-\color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right) + \pi \cdot 0.5 \]
    9. distribute-rgt-neg-in10.7%

      \[\leadsto \color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \left(-\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)} + \pi \cdot 0.5 \]
    10. fma-def10.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right)} \]
    11. pow210.7%

      \[\leadsto \mathsf{fma}\left(\color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
  5. Applied egg-rr10.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left({\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right)} \]
  6. Step-by-step derivation
    1. add-cube-cbrt10.7%

      \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
    2. unpow210.7%

      \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
    3. cbrt-prod10.7%

      \[\leadsto \mathsf{fma}\left({\color{blue}{\left(\sqrt[3]{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}} \cdot \sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
  7. Applied egg-rr10.7%

    \[\leadsto \mathsf{fma}\left({\color{blue}{\left(\sqrt[3]{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}} \cdot \sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
  8. Final simplification10.7%

    \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}} \cdot \sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]

Alternative 2: 10.3% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{\sin^{-1} \left(1 - x\right)}\\ \mathsf{fma}\left({t_0}^{2}, -{\left(\sqrt[3]{t_0}\right)}^{3}, \pi \cdot 0.5\right) \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (cbrt (asin (- 1.0 x)))))
   (fma (pow t_0 2.0) (- (pow (cbrt t_0) 3.0)) (* PI 0.5))))
double code(double x) {
	double t_0 = cbrt(asin((1.0 - x)));
	return fma(pow(t_0, 2.0), -pow(cbrt(t_0), 3.0), (((double) M_PI) * 0.5));
}
function code(x)
	t_0 = cbrt(asin(Float64(1.0 - x)))
	return fma((t_0 ^ 2.0), Float64(-(cbrt(t_0) ^ 3.0)), Float64(pi * 0.5))
end
code[x_] := Block[{t$95$0 = N[Power[N[ArcSin[N[(1.0 - x), $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision]}, N[(N[Power[t$95$0, 2.0], $MachinePrecision] * (-N[Power[N[Power[t$95$0, 1/3], $MachinePrecision], 3.0], $MachinePrecision]) + N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt[3]{\sin^{-1} \left(1 - x\right)}\\
\mathsf{fma}\left({t_0}^{2}, -{\left(\sqrt[3]{t_0}\right)}^{3}, \pi \cdot 0.5\right)
\end{array}
\end{array}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Step-by-step derivation
    1. add-cbrt-cube7.1%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
    2. pow1/37.1%

      \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
    3. pow37.1%

      \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
  3. Applied egg-rr7.1%

    \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
  4. Step-by-step derivation
    1. unpow1/37.1%

      \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
    2. rem-cbrt-cube7.1%

      \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
    3. acos-asin7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} - \sin^{-1} \left(1 - x\right)} \]
    4. div-inv7.1%

      \[\leadsto \color{blue}{\pi \cdot \frac{1}{2}} - \sin^{-1} \left(1 - x\right) \]
    5. metadata-eval7.1%

      \[\leadsto \pi \cdot \color{blue}{0.5} - \sin^{-1} \left(1 - x\right) \]
    6. sub-neg7.1%

      \[\leadsto \color{blue}{\pi \cdot 0.5 + \left(-\sin^{-1} \left(1 - x\right)\right)} \]
    7. +-commutative7.1%

      \[\leadsto \color{blue}{\left(-\sin^{-1} \left(1 - x\right)\right) + \pi \cdot 0.5} \]
    8. add-cube-cbrt10.7%

      \[\leadsto \left(-\color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right) + \pi \cdot 0.5 \]
    9. distribute-rgt-neg-in10.7%

      \[\leadsto \color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \left(-\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)} + \pi \cdot 0.5 \]
    10. fma-def10.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right)} \]
    11. pow210.7%

      \[\leadsto \mathsf{fma}\left(\color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
  5. Applied egg-rr10.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left({\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right)} \]
  6. Step-by-step derivation
    1. add-cube-cbrt10.7%

      \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}, -\color{blue}{\left(\sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}} \cdot \sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right) \cdot \sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}}, \pi \cdot 0.5\right) \]
    2. pow310.7%

      \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}, -\color{blue}{{\left(\sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}^{3}}, \pi \cdot 0.5\right) \]
  7. Applied egg-rr10.7%

    \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}, -\color{blue}{{\left(\sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}^{3}}, \pi \cdot 0.5\right) \]
  8. Final simplification10.7%

    \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}, -{\left(\sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}^{3}, \pi \cdot 0.5\right) \]

Alternative 3: 10.3% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{\sin^{-1} \left(1 - x\right)}\\ \mathsf{fma}\left({\left(\mathsf{expm1}\left(\mathsf{log1p}\left(t_0\right)\right)\right)}^{2}, -t_0, \pi \cdot 0.5\right) \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (cbrt (asin (- 1.0 x)))))
   (fma (pow (expm1 (log1p t_0)) 2.0) (- t_0) (* PI 0.5))))
double code(double x) {
	double t_0 = cbrt(asin((1.0 - x)));
	return fma(pow(expm1(log1p(t_0)), 2.0), -t_0, (((double) M_PI) * 0.5));
}
function code(x)
	t_0 = cbrt(asin(Float64(1.0 - x)))
	return fma((expm1(log1p(t_0)) ^ 2.0), Float64(-t_0), Float64(pi * 0.5))
end
code[x_] := Block[{t$95$0 = N[Power[N[ArcSin[N[(1.0 - x), $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision]}, N[(N[Power[N[(Exp[N[Log[1 + t$95$0], $MachinePrecision]] - 1), $MachinePrecision], 2.0], $MachinePrecision] * (-t$95$0) + N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt[3]{\sin^{-1} \left(1 - x\right)}\\
\mathsf{fma}\left({\left(\mathsf{expm1}\left(\mathsf{log1p}\left(t_0\right)\right)\right)}^{2}, -t_0, \pi \cdot 0.5\right)
\end{array}
\end{array}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Step-by-step derivation
    1. add-cbrt-cube7.1%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
    2. pow1/37.1%

      \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
    3. pow37.1%

      \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
  3. Applied egg-rr7.1%

    \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
  4. Step-by-step derivation
    1. unpow1/37.1%

      \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
    2. rem-cbrt-cube7.1%

      \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
    3. acos-asin7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} - \sin^{-1} \left(1 - x\right)} \]
    4. div-inv7.1%

      \[\leadsto \color{blue}{\pi \cdot \frac{1}{2}} - \sin^{-1} \left(1 - x\right) \]
    5. metadata-eval7.1%

      \[\leadsto \pi \cdot \color{blue}{0.5} - \sin^{-1} \left(1 - x\right) \]
    6. sub-neg7.1%

      \[\leadsto \color{blue}{\pi \cdot 0.5 + \left(-\sin^{-1} \left(1 - x\right)\right)} \]
    7. +-commutative7.1%

      \[\leadsto \color{blue}{\left(-\sin^{-1} \left(1 - x\right)\right) + \pi \cdot 0.5} \]
    8. add-cube-cbrt10.7%

      \[\leadsto \left(-\color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right) + \pi \cdot 0.5 \]
    9. distribute-rgt-neg-in10.7%

      \[\leadsto \color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \left(-\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)} + \pi \cdot 0.5 \]
    10. fma-def10.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right)} \]
    11. pow210.7%

      \[\leadsto \mathsf{fma}\left(\color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
  5. Applied egg-rr10.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left({\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right)} \]
  6. Step-by-step derivation
    1. expm1-log1p-u10.7%

      \[\leadsto \mathsf{fma}\left({\color{blue}{\left(\mathsf{expm1}\left(\mathsf{log1p}\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)\right)\right)}}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
  7. Applied egg-rr10.7%

    \[\leadsto \mathsf{fma}\left({\color{blue}{\left(\mathsf{expm1}\left(\mathsf{log1p}\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)\right)\right)}}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
  8. Final simplification10.7%

    \[\leadsto \mathsf{fma}\left({\left(\mathsf{expm1}\left(\mathsf{log1p}\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)\right)\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]

Alternative 4: 10.3% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{\pi \cdot 0.5}\\ \pi \cdot 0.5 - \mathsf{fma}\left(t_0, t_0, -\cos^{-1} \left(1 - x\right)\right) \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (sqrt (* PI 0.5))))
   (- (* PI 0.5) (fma t_0 t_0 (- (acos (- 1.0 x)))))))
double code(double x) {
	double t_0 = sqrt((((double) M_PI) * 0.5));
	return (((double) M_PI) * 0.5) - fma(t_0, t_0, -acos((1.0 - x)));
}
function code(x)
	t_0 = sqrt(Float64(pi * 0.5))
	return Float64(Float64(pi * 0.5) - fma(t_0, t_0, Float64(-acos(Float64(1.0 - x)))))
end
code[x_] := Block[{t$95$0 = N[Sqrt[N[(Pi * 0.5), $MachinePrecision]], $MachinePrecision]}, N[(N[(Pi * 0.5), $MachinePrecision] - N[(t$95$0 * t$95$0 + (-N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision])), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt{\pi \cdot 0.5}\\
\pi \cdot 0.5 - \mathsf{fma}\left(t_0, t_0, -\cos^{-1} \left(1 - x\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Step-by-step derivation
    1. acos-asin7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} - \sin^{-1} \left(1 - x\right)} \]
    2. sub-neg7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} + \left(-\sin^{-1} \left(1 - x\right)\right)} \]
    3. div-inv7.1%

      \[\leadsto \color{blue}{\pi \cdot \frac{1}{2}} + \left(-\sin^{-1} \left(1 - x\right)\right) \]
    4. metadata-eval7.1%

      \[\leadsto \pi \cdot \color{blue}{0.5} + \left(-\sin^{-1} \left(1 - x\right)\right) \]
  3. Applied egg-rr7.1%

    \[\leadsto \color{blue}{\pi \cdot 0.5 + \left(-\sin^{-1} \left(1 - x\right)\right)} \]
  4. Step-by-step derivation
    1. sub-neg7.1%

      \[\leadsto \color{blue}{\pi \cdot 0.5 - \sin^{-1} \left(1 - x\right)} \]
  5. Simplified7.1%

    \[\leadsto \color{blue}{\pi \cdot 0.5 - \sin^{-1} \left(1 - x\right)} \]
  6. Step-by-step derivation
    1. asin-acos7.1%

      \[\leadsto \pi \cdot 0.5 - \color{blue}{\left(\frac{\pi}{2} - \cos^{-1} \left(1 - x\right)\right)} \]
    2. div-inv7.1%

      \[\leadsto \pi \cdot 0.5 - \left(\color{blue}{\pi \cdot \frac{1}{2}} - \cos^{-1} \left(1 - x\right)\right) \]
    3. metadata-eval7.1%

      \[\leadsto \pi \cdot 0.5 - \left(\pi \cdot \color{blue}{0.5} - \cos^{-1} \left(1 - x\right)\right) \]
    4. add-sqr-sqrt10.7%

      \[\leadsto \pi \cdot 0.5 - \left(\color{blue}{\sqrt{\pi \cdot 0.5} \cdot \sqrt{\pi \cdot 0.5}} - \cos^{-1} \left(1 - x\right)\right) \]
    5. fma-neg10.7%

      \[\leadsto \pi \cdot 0.5 - \color{blue}{\mathsf{fma}\left(\sqrt{\pi \cdot 0.5}, \sqrt{\pi \cdot 0.5}, -\cos^{-1} \left(1 - x\right)\right)} \]
  7. Applied egg-rr10.7%

    \[\leadsto \pi \cdot 0.5 - \color{blue}{\mathsf{fma}\left(\sqrt{\pi \cdot 0.5}, \sqrt{\pi \cdot 0.5}, -\cos^{-1} \left(1 - x\right)\right)} \]
  8. Final simplification10.7%

    \[\leadsto \pi \cdot 0.5 - \mathsf{fma}\left(\sqrt{\pi \cdot 0.5}, \sqrt{\pi \cdot 0.5}, -\cos^{-1} \left(1 - x\right)\right) \]

Alternative 5: 10.4% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\sqrt{\pi} \cdot \sqrt{0.5}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (fma (* (sqrt PI) (sqrt 0.5)) (sqrt (* PI 0.5)) (- (asin (- 1.0 x)))))
double code(double x) {
	return fma((sqrt(((double) M_PI)) * sqrt(0.5)), sqrt((((double) M_PI) * 0.5)), -asin((1.0 - x)));
}
function code(x)
	return fma(Float64(sqrt(pi) * sqrt(0.5)), sqrt(Float64(pi * 0.5)), Float64(-asin(Float64(1.0 - x))))
end
code[x_] := N[(N[(N[Sqrt[Pi], $MachinePrecision] * N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(Pi * 0.5), $MachinePrecision]], $MachinePrecision] + (-N[ArcSin[N[(1.0 - x), $MachinePrecision]], $MachinePrecision])), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\sqrt{\pi} \cdot \sqrt{0.5}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right)
\end{array}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Step-by-step derivation
    1. add-cbrt-cube7.1%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
    2. pow1/37.1%

      \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
    3. pow37.1%

      \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
  3. Applied egg-rr7.1%

    \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
  4. Step-by-step derivation
    1. unpow1/37.1%

      \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
    2. rem-cbrt-cube7.1%

      \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
    3. acos-asin7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} - \sin^{-1} \left(1 - x\right)} \]
    4. div-inv7.1%

      \[\leadsto \color{blue}{\pi \cdot \frac{1}{2}} - \sin^{-1} \left(1 - x\right) \]
    5. metadata-eval7.1%

      \[\leadsto \pi \cdot \color{blue}{0.5} - \sin^{-1} \left(1 - x\right) \]
    6. add-sqr-sqrt5.3%

      \[\leadsto \color{blue}{\sqrt{\pi \cdot 0.5} \cdot \sqrt{\pi \cdot 0.5}} - \sin^{-1} \left(1 - x\right) \]
    7. fma-neg5.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt{\pi \cdot 0.5}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right)} \]
  5. Applied egg-rr5.3%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt{\pi \cdot 0.5}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right)} \]
  6. Step-by-step derivation
    1. sqrt-prod10.7%

      \[\leadsto \mathsf{fma}\left(\color{blue}{\sqrt{\pi} \cdot \sqrt{0.5}}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right) \]
  7. Applied egg-rr10.7%

    \[\leadsto \mathsf{fma}\left(\color{blue}{\sqrt{\pi} \cdot \sqrt{0.5}}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right) \]
  8. Final simplification10.7%

    \[\leadsto \mathsf{fma}\left(\sqrt{\pi} \cdot \sqrt{0.5}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right) \]

Alternative 6: 10.3% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \pi \cdot 0.5 - {\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{3} \end{array} \]
(FPCore (x)
 :precision binary64
 (- (* PI 0.5) (pow (cbrt (asin (- 1.0 x))) 3.0)))
double code(double x) {
	return (((double) M_PI) * 0.5) - pow(cbrt(asin((1.0 - x))), 3.0);
}
public static double code(double x) {
	return (Math.PI * 0.5) - Math.pow(Math.cbrt(Math.asin((1.0 - x))), 3.0);
}
function code(x)
	return Float64(Float64(pi * 0.5) - (cbrt(asin(Float64(1.0 - x))) ^ 3.0))
end
code[x_] := N[(N[(Pi * 0.5), $MachinePrecision] - N[Power[N[Power[N[ArcSin[N[(1.0 - x), $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision], 3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\pi \cdot 0.5 - {\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{3}
\end{array}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Step-by-step derivation
    1. acos-asin7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} - \sin^{-1} \left(1 - x\right)} \]
    2. sub-neg7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} + \left(-\sin^{-1} \left(1 - x\right)\right)} \]
    3. div-inv7.1%

      \[\leadsto \color{blue}{\pi \cdot \frac{1}{2}} + \left(-\sin^{-1} \left(1 - x\right)\right) \]
    4. metadata-eval7.1%

      \[\leadsto \pi \cdot \color{blue}{0.5} + \left(-\sin^{-1} \left(1 - x\right)\right) \]
  3. Applied egg-rr7.1%

    \[\leadsto \color{blue}{\pi \cdot 0.5 + \left(-\sin^{-1} \left(1 - x\right)\right)} \]
  4. Step-by-step derivation
    1. sub-neg7.1%

      \[\leadsto \color{blue}{\pi \cdot 0.5 - \sin^{-1} \left(1 - x\right)} \]
  5. Simplified7.1%

    \[\leadsto \color{blue}{\pi \cdot 0.5 - \sin^{-1} \left(1 - x\right)} \]
  6. Step-by-step derivation
    1. add-cube-cbrt10.7%

      \[\leadsto \pi \cdot 0.5 - \color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}} \]
    2. pow310.7%

      \[\leadsto \pi \cdot 0.5 - \color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{3}} \]
  7. Applied egg-rr10.7%

    \[\leadsto \pi \cdot 0.5 - \color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{3}} \]
  8. Final simplification10.7%

    \[\leadsto \pi \cdot 0.5 - {\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{3} \]

Alternative 7: 10.3% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \pi \cdot {\left(\sqrt{0.5}\right)}^{2} - \sin^{-1} \left(1 - x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (- (* PI (pow (sqrt 0.5) 2.0)) (asin (- 1.0 x))))
double code(double x) {
	return (((double) M_PI) * pow(sqrt(0.5), 2.0)) - asin((1.0 - x));
}
public static double code(double x) {
	return (Math.PI * Math.pow(Math.sqrt(0.5), 2.0)) - Math.asin((1.0 - x));
}
def code(x):
	return (math.pi * math.pow(math.sqrt(0.5), 2.0)) - math.asin((1.0 - x))
function code(x)
	return Float64(Float64(pi * (sqrt(0.5) ^ 2.0)) - asin(Float64(1.0 - x)))
end
function tmp = code(x)
	tmp = (pi * (sqrt(0.5) ^ 2.0)) - asin((1.0 - x));
end
code[x_] := N[(N[(Pi * N[Power[N[Sqrt[0.5], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] - N[ArcSin[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\pi \cdot {\left(\sqrt{0.5}\right)}^{2} - \sin^{-1} \left(1 - x\right)
\end{array}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Step-by-step derivation
    1. add-cbrt-cube7.1%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
    2. pow1/37.1%

      \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
    3. pow37.1%

      \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
  3. Applied egg-rr7.1%

    \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
  4. Step-by-step derivation
    1. unpow1/37.1%

      \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
    2. rem-cbrt-cube7.1%

      \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
    3. acos-asin7.1%

      \[\leadsto \color{blue}{\frac{\pi}{2} - \sin^{-1} \left(1 - x\right)} \]
    4. div-inv7.1%

      \[\leadsto \color{blue}{\pi \cdot \frac{1}{2}} - \sin^{-1} \left(1 - x\right) \]
    5. metadata-eval7.1%

      \[\leadsto \pi \cdot \color{blue}{0.5} - \sin^{-1} \left(1 - x\right) \]
    6. add-sqr-sqrt5.3%

      \[\leadsto \color{blue}{\sqrt{\pi \cdot 0.5} \cdot \sqrt{\pi \cdot 0.5}} - \sin^{-1} \left(1 - x\right) \]
    7. fma-neg5.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt{\pi \cdot 0.5}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right)} \]
  5. Applied egg-rr5.3%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt{\pi \cdot 0.5}, \sqrt{\pi \cdot 0.5}, -\sin^{-1} \left(1 - x\right)\right)} \]
  6. Taylor expanded in x around 0 10.7%

    \[\leadsto \color{blue}{{\left(\sqrt{0.5}\right)}^{2} \cdot \pi - \sin^{-1} \left(1 - x\right)} \]
  7. Final simplification10.7%

    \[\leadsto \pi \cdot {\left(\sqrt{0.5}\right)}^{2} - \sin^{-1} \left(1 - x\right) \]

Alternative 8: 9.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos^{-1} \left(1 - x\right) + -1\\ \mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\ \;\;\;\;1 + \left|t_0\right|\\ \mathbf{else}:\\ \;\;\;\;1 + \sqrt[3]{{t_0}^{3}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (acos (- 1.0 x)) -1.0)))
   (if (<= x 5.6e-17) (+ 1.0 (fabs t_0)) (+ 1.0 (cbrt (pow t_0 3.0))))))
double code(double x) {
	double t_0 = acos((1.0 - x)) + -1.0;
	double tmp;
	if (x <= 5.6e-17) {
		tmp = 1.0 + fabs(t_0);
	} else {
		tmp = 1.0 + cbrt(pow(t_0, 3.0));
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = Math.acos((1.0 - x)) + -1.0;
	double tmp;
	if (x <= 5.6e-17) {
		tmp = 1.0 + Math.abs(t_0);
	} else {
		tmp = 1.0 + Math.cbrt(Math.pow(t_0, 3.0));
	}
	return tmp;
}
function code(x)
	t_0 = Float64(acos(Float64(1.0 - x)) + -1.0)
	tmp = 0.0
	if (x <= 5.6e-17)
		tmp = Float64(1.0 + abs(t_0));
	else
		tmp = Float64(1.0 + cbrt((t_0 ^ 3.0)));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[(N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision] + -1.0), $MachinePrecision]}, If[LessEqual[x, 5.6e-17], N[(1.0 + N[Abs[t$95$0], $MachinePrecision]), $MachinePrecision], N[(1.0 + N[Power[N[Power[t$95$0, 3.0], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos^{-1} \left(1 - x\right) + -1\\
\mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\
\;\;\;\;1 + \left|t_0\right|\\

\mathbf{else}:\\
\;\;\;\;1 + \sqrt[3]{{t_0}^{3}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 5.5999999999999998e-17

    1. Initial program 3.8%

      \[\cos^{-1} \left(1 - x\right) \]
    2. Step-by-step derivation
      1. add-cbrt-cube3.8%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
      2. pow1/33.8%

        \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
      3. pow33.8%

        \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
    3. Applied egg-rr3.8%

      \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
    4. Step-by-step derivation
      1. unpow1/33.8%

        \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
      2. rem-cbrt-cube3.8%

        \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
      3. expm1-log1p-u3.8%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)\right)} \]
      4. expm1-udef3.8%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)} - 1} \]
      5. log1p-udef3.8%

        \[\leadsto e^{\color{blue}{\log \left(1 + \cos^{-1} \left(1 - x\right)\right)}} - 1 \]
      6. *-rgt-identity3.8%

        \[\leadsto e^{\log \color{blue}{\left(\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1\right)}} - 1 \]
      7. add-exp-log3.8%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1} - 1 \]
      8. *-rgt-identity3.8%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right)} - 1 \]
      9. associate--l+3.8%

        \[\leadsto \color{blue}{1 + \left(\cos^{-1} \left(1 - x\right) - 1\right)} \]
      10. +-commutative3.8%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) - 1\right) + 1} \]
      11. sub-neg3.8%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + \left(-1\right)\right)} + 1 \]
      12. metadata-eval3.8%

        \[\leadsto \left(\cos^{-1} \left(1 - x\right) + \color{blue}{-1}\right) + 1 \]
    5. Applied egg-rr3.8%

      \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) + 1} \]
    6. Step-by-step derivation
      1. add-sqr-sqrt0.0%

        \[\leadsto \color{blue}{\sqrt{\cos^{-1} \left(1 - x\right) + -1} \cdot \sqrt{\cos^{-1} \left(1 - x\right) + -1}} + 1 \]
      2. sqrt-unprod6.6%

        \[\leadsto \color{blue}{\sqrt{\left(\cos^{-1} \left(1 - x\right) + -1\right) \cdot \left(\cos^{-1} \left(1 - x\right) + -1\right)}} + 1 \]
      3. pow26.6%

        \[\leadsto \sqrt{\color{blue}{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{2}}} + 1 \]
    7. Applied egg-rr6.6%

      \[\leadsto \color{blue}{\sqrt{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{2}}} + 1 \]
    8. Step-by-step derivation
      1. unpow26.6%

        \[\leadsto \sqrt{\color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) \cdot \left(\cos^{-1} \left(1 - x\right) + -1\right)}} + 1 \]
      2. rem-sqrt-square6.6%

        \[\leadsto \color{blue}{\left|\cos^{-1} \left(1 - x\right) + -1\right|} + 1 \]
    9. Simplified6.6%

      \[\leadsto \color{blue}{\left|\cos^{-1} \left(1 - x\right) + -1\right|} + 1 \]

    if 5.5999999999999998e-17 < x

    1. Initial program 73.4%

      \[\cos^{-1} \left(1 - x\right) \]
    2. Step-by-step derivation
      1. add-cbrt-cube73.2%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
      2. pow1/373.4%

        \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
      3. pow373.4%

        \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
    3. Applied egg-rr73.4%

      \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
    4. Step-by-step derivation
      1. unpow1/373.3%

        \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
      2. rem-cbrt-cube73.4%

        \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
      3. expm1-log1p-u73.3%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)\right)} \]
      4. expm1-udef73.4%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)} - 1} \]
      5. log1p-udef73.4%

        \[\leadsto e^{\color{blue}{\log \left(1 + \cos^{-1} \left(1 - x\right)\right)}} - 1 \]
      6. *-rgt-identity73.4%

        \[\leadsto e^{\log \color{blue}{\left(\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1\right)}} - 1 \]
      7. add-exp-log73.4%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1} - 1 \]
      8. *-rgt-identity73.4%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right)} - 1 \]
      9. associate--l+73.4%

        \[\leadsto \color{blue}{1 + \left(\cos^{-1} \left(1 - x\right) - 1\right)} \]
      10. +-commutative73.4%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) - 1\right) + 1} \]
      11. sub-neg73.4%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + \left(-1\right)\right)} + 1 \]
      12. metadata-eval73.4%

        \[\leadsto \left(\cos^{-1} \left(1 - x\right) + \color{blue}{-1}\right) + 1 \]
    5. Applied egg-rr73.4%

      \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) + 1} \]
    6. Step-by-step derivation
      1. add-cbrt-cube73.7%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\left(\cos^{-1} \left(1 - x\right) + -1\right) \cdot \left(\cos^{-1} \left(1 - x\right) + -1\right)\right) \cdot \left(\cos^{-1} \left(1 - x\right) + -1\right)}} + 1 \]
      2. pow373.7%

        \[\leadsto \sqrt[3]{\color{blue}{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{3}}} + 1 \]
    7. Applied egg-rr73.7%

      \[\leadsto \color{blue}{\sqrt[3]{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{3}}} + 1 \]
  3. Recombined 2 regimes into one program.
  4. Final simplification9.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\ \;\;\;\;1 + \left|\cos^{-1} \left(1 - x\right) + -1\right|\\ \mathbf{else}:\\ \;\;\;\;1 + \sqrt[3]{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{3}}\\ \end{array} \]

Alternative 9: 9.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos^{-1} \left(1 - x\right) + -1\\ \mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\ \;\;\;\;1 + \left|t_0\right|\\ \mathbf{else}:\\ \;\;\;\;e^{\mathsf{log1p}\left(t_0\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (acos (- 1.0 x)) -1.0)))
   (if (<= x 5.6e-17) (+ 1.0 (fabs t_0)) (exp (log1p t_0)))))
double code(double x) {
	double t_0 = acos((1.0 - x)) + -1.0;
	double tmp;
	if (x <= 5.6e-17) {
		tmp = 1.0 + fabs(t_0);
	} else {
		tmp = exp(log1p(t_0));
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = Math.acos((1.0 - x)) + -1.0;
	double tmp;
	if (x <= 5.6e-17) {
		tmp = 1.0 + Math.abs(t_0);
	} else {
		tmp = Math.exp(Math.log1p(t_0));
	}
	return tmp;
}
def code(x):
	t_0 = math.acos((1.0 - x)) + -1.0
	tmp = 0
	if x <= 5.6e-17:
		tmp = 1.0 + math.fabs(t_0)
	else:
		tmp = math.exp(math.log1p(t_0))
	return tmp
function code(x)
	t_0 = Float64(acos(Float64(1.0 - x)) + -1.0)
	tmp = 0.0
	if (x <= 5.6e-17)
		tmp = Float64(1.0 + abs(t_0));
	else
		tmp = exp(log1p(t_0));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[(N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision] + -1.0), $MachinePrecision]}, If[LessEqual[x, 5.6e-17], N[(1.0 + N[Abs[t$95$0], $MachinePrecision]), $MachinePrecision], N[Exp[N[Log[1 + t$95$0], $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos^{-1} \left(1 - x\right) + -1\\
\mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\
\;\;\;\;1 + \left|t_0\right|\\

\mathbf{else}:\\
\;\;\;\;e^{\mathsf{log1p}\left(t_0\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 5.5999999999999998e-17

    1. Initial program 3.8%

      \[\cos^{-1} \left(1 - x\right) \]
    2. Step-by-step derivation
      1. add-cbrt-cube3.8%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
      2. pow1/33.8%

        \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
      3. pow33.8%

        \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
    3. Applied egg-rr3.8%

      \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
    4. Step-by-step derivation
      1. unpow1/33.8%

        \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
      2. rem-cbrt-cube3.8%

        \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
      3. expm1-log1p-u3.8%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)\right)} \]
      4. expm1-udef3.8%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)} - 1} \]
      5. log1p-udef3.8%

        \[\leadsto e^{\color{blue}{\log \left(1 + \cos^{-1} \left(1 - x\right)\right)}} - 1 \]
      6. *-rgt-identity3.8%

        \[\leadsto e^{\log \color{blue}{\left(\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1\right)}} - 1 \]
      7. add-exp-log3.8%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1} - 1 \]
      8. *-rgt-identity3.8%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right)} - 1 \]
      9. associate--l+3.8%

        \[\leadsto \color{blue}{1 + \left(\cos^{-1} \left(1 - x\right) - 1\right)} \]
      10. +-commutative3.8%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) - 1\right) + 1} \]
      11. sub-neg3.8%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + \left(-1\right)\right)} + 1 \]
      12. metadata-eval3.8%

        \[\leadsto \left(\cos^{-1} \left(1 - x\right) + \color{blue}{-1}\right) + 1 \]
    5. Applied egg-rr3.8%

      \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) + 1} \]
    6. Step-by-step derivation
      1. add-sqr-sqrt0.0%

        \[\leadsto \color{blue}{\sqrt{\cos^{-1} \left(1 - x\right) + -1} \cdot \sqrt{\cos^{-1} \left(1 - x\right) + -1}} + 1 \]
      2. sqrt-unprod6.6%

        \[\leadsto \color{blue}{\sqrt{\left(\cos^{-1} \left(1 - x\right) + -1\right) \cdot \left(\cos^{-1} \left(1 - x\right) + -1\right)}} + 1 \]
      3. pow26.6%

        \[\leadsto \sqrt{\color{blue}{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{2}}} + 1 \]
    7. Applied egg-rr6.6%

      \[\leadsto \color{blue}{\sqrt{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{2}}} + 1 \]
    8. Step-by-step derivation
      1. unpow26.6%

        \[\leadsto \sqrt{\color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) \cdot \left(\cos^{-1} \left(1 - x\right) + -1\right)}} + 1 \]
      2. rem-sqrt-square6.6%

        \[\leadsto \color{blue}{\left|\cos^{-1} \left(1 - x\right) + -1\right|} + 1 \]
    9. Simplified6.6%

      \[\leadsto \color{blue}{\left|\cos^{-1} \left(1 - x\right) + -1\right|} + 1 \]

    if 5.5999999999999998e-17 < x

    1. Initial program 73.4%

      \[\cos^{-1} \left(1 - x\right) \]
    2. Step-by-step derivation
      1. add-exp-log73.4%

        \[\leadsto \color{blue}{e^{\log \cos^{-1} \left(1 - x\right)}} \]
    3. Applied egg-rr73.4%

      \[\leadsto \color{blue}{e^{\log \cos^{-1} \left(1 - x\right)}} \]
    4. Step-by-step derivation
      1. log1p-expm1-u73.5%

        \[\leadsto e^{\color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log \cos^{-1} \left(1 - x\right)\right)\right)}} \]
      2. expm1-udef73.5%

        \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{e^{\log \cos^{-1} \left(1 - x\right)} - 1}\right)} \]
      3. add-exp-log73.5%

        \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\cos^{-1} \left(1 - x\right)} - 1\right)} \]
      4. sub-neg73.5%

        \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\cos^{-1} \left(1 - x\right) + \left(-1\right)}\right)} \]
      5. metadata-eval73.5%

        \[\leadsto e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right) + \color{blue}{-1}\right)} \]
    5. Applied egg-rr73.5%

      \[\leadsto e^{\color{blue}{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right) + -1\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification9.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\ \;\;\;\;1 + \left|\cos^{-1} \left(1 - x\right) + -1\right|\\ \mathbf{else}:\\ \;\;\;\;e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right) + -1\right)}\\ \end{array} \]

Alternative 10: 9.4% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos^{-1} \left(1 - x\right) + -1\\ \mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\ \;\;\;\;1 + \left|t_0\right|\\ \mathbf{else}:\\ \;\;\;\;1 + t_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (+ (acos (- 1.0 x)) -1.0)))
   (if (<= x 5.6e-17) (+ 1.0 (fabs t_0)) (+ 1.0 t_0))))
double code(double x) {
	double t_0 = acos((1.0 - x)) + -1.0;
	double tmp;
	if (x <= 5.6e-17) {
		tmp = 1.0 + fabs(t_0);
	} else {
		tmp = 1.0 + t_0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = acos((1.0d0 - x)) + (-1.0d0)
    if (x <= 5.6d-17) then
        tmp = 1.0d0 + abs(t_0)
    else
        tmp = 1.0d0 + t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = Math.acos((1.0 - x)) + -1.0;
	double tmp;
	if (x <= 5.6e-17) {
		tmp = 1.0 + Math.abs(t_0);
	} else {
		tmp = 1.0 + t_0;
	}
	return tmp;
}
def code(x):
	t_0 = math.acos((1.0 - x)) + -1.0
	tmp = 0
	if x <= 5.6e-17:
		tmp = 1.0 + math.fabs(t_0)
	else:
		tmp = 1.0 + t_0
	return tmp
function code(x)
	t_0 = Float64(acos(Float64(1.0 - x)) + -1.0)
	tmp = 0.0
	if (x <= 5.6e-17)
		tmp = Float64(1.0 + abs(t_0));
	else
		tmp = Float64(1.0 + t_0);
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = acos((1.0 - x)) + -1.0;
	tmp = 0.0;
	if (x <= 5.6e-17)
		tmp = 1.0 + abs(t_0);
	else
		tmp = 1.0 + t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision] + -1.0), $MachinePrecision]}, If[LessEqual[x, 5.6e-17], N[(1.0 + N[Abs[t$95$0], $MachinePrecision]), $MachinePrecision], N[(1.0 + t$95$0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos^{-1} \left(1 - x\right) + -1\\
\mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\
\;\;\;\;1 + \left|t_0\right|\\

\mathbf{else}:\\
\;\;\;\;1 + t_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 5.5999999999999998e-17

    1. Initial program 3.8%

      \[\cos^{-1} \left(1 - x\right) \]
    2. Step-by-step derivation
      1. add-cbrt-cube3.8%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
      2. pow1/33.8%

        \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
      3. pow33.8%

        \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
    3. Applied egg-rr3.8%

      \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
    4. Step-by-step derivation
      1. unpow1/33.8%

        \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
      2. rem-cbrt-cube3.8%

        \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
      3. expm1-log1p-u3.8%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)\right)} \]
      4. expm1-udef3.8%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)} - 1} \]
      5. log1p-udef3.8%

        \[\leadsto e^{\color{blue}{\log \left(1 + \cos^{-1} \left(1 - x\right)\right)}} - 1 \]
      6. *-rgt-identity3.8%

        \[\leadsto e^{\log \color{blue}{\left(\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1\right)}} - 1 \]
      7. add-exp-log3.8%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1} - 1 \]
      8. *-rgt-identity3.8%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right)} - 1 \]
      9. associate--l+3.8%

        \[\leadsto \color{blue}{1 + \left(\cos^{-1} \left(1 - x\right) - 1\right)} \]
      10. +-commutative3.8%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) - 1\right) + 1} \]
      11. sub-neg3.8%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + \left(-1\right)\right)} + 1 \]
      12. metadata-eval3.8%

        \[\leadsto \left(\cos^{-1} \left(1 - x\right) + \color{blue}{-1}\right) + 1 \]
    5. Applied egg-rr3.8%

      \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) + 1} \]
    6. Step-by-step derivation
      1. add-sqr-sqrt0.0%

        \[\leadsto \color{blue}{\sqrt{\cos^{-1} \left(1 - x\right) + -1} \cdot \sqrt{\cos^{-1} \left(1 - x\right) + -1}} + 1 \]
      2. sqrt-unprod6.6%

        \[\leadsto \color{blue}{\sqrt{\left(\cos^{-1} \left(1 - x\right) + -1\right) \cdot \left(\cos^{-1} \left(1 - x\right) + -1\right)}} + 1 \]
      3. pow26.6%

        \[\leadsto \sqrt{\color{blue}{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{2}}} + 1 \]
    7. Applied egg-rr6.6%

      \[\leadsto \color{blue}{\sqrt{{\left(\cos^{-1} \left(1 - x\right) + -1\right)}^{2}}} + 1 \]
    8. Step-by-step derivation
      1. unpow26.6%

        \[\leadsto \sqrt{\color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) \cdot \left(\cos^{-1} \left(1 - x\right) + -1\right)}} + 1 \]
      2. rem-sqrt-square6.6%

        \[\leadsto \color{blue}{\left|\cos^{-1} \left(1 - x\right) + -1\right|} + 1 \]
    9. Simplified6.6%

      \[\leadsto \color{blue}{\left|\cos^{-1} \left(1 - x\right) + -1\right|} + 1 \]

    if 5.5999999999999998e-17 < x

    1. Initial program 73.4%

      \[\cos^{-1} \left(1 - x\right) \]
    2. Step-by-step derivation
      1. add-cbrt-cube73.2%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
      2. pow1/373.4%

        \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
      3. pow373.4%

        \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
    3. Applied egg-rr73.4%

      \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
    4. Step-by-step derivation
      1. unpow1/373.3%

        \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
      2. rem-cbrt-cube73.4%

        \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
      3. expm1-log1p-u73.3%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)\right)} \]
      4. expm1-udef73.4%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)} - 1} \]
      5. log1p-udef73.4%

        \[\leadsto e^{\color{blue}{\log \left(1 + \cos^{-1} \left(1 - x\right)\right)}} - 1 \]
      6. *-rgt-identity73.4%

        \[\leadsto e^{\log \color{blue}{\left(\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1\right)}} - 1 \]
      7. add-exp-log73.4%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1} - 1 \]
      8. *-rgt-identity73.4%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right)} - 1 \]
      9. associate--l+73.4%

        \[\leadsto \color{blue}{1 + \left(\cos^{-1} \left(1 - x\right) - 1\right)} \]
      10. +-commutative73.4%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) - 1\right) + 1} \]
      11. sub-neg73.4%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + \left(-1\right)\right)} + 1 \]
      12. metadata-eval73.4%

        \[\leadsto \left(\cos^{-1} \left(1 - x\right) + \color{blue}{-1}\right) + 1 \]
    5. Applied egg-rr73.4%

      \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) + 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification9.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 5.6 \cdot 10^{-17}:\\ \;\;\;\;1 + \left|\cos^{-1} \left(1 - x\right) + -1\right|\\ \mathbf{else}:\\ \;\;\;\;1 + \left(\cos^{-1} \left(1 - x\right) + -1\right)\\ \end{array} \]

Alternative 11: 6.8% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos^{-1} \left(1 - x\right)\\ \mathbf{if}\;1 - x \leq 1:\\ \;\;\;\;1 + \left(t_0 + -1\right)\\ \mathbf{else}:\\ \;\;\;\;\pi - t_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (acos (- 1.0 x))))
   (if (<= (- 1.0 x) 1.0) (+ 1.0 (+ t_0 -1.0)) (- PI t_0))))
double code(double x) {
	double t_0 = acos((1.0 - x));
	double tmp;
	if ((1.0 - x) <= 1.0) {
		tmp = 1.0 + (t_0 + -1.0);
	} else {
		tmp = ((double) M_PI) - t_0;
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = Math.acos((1.0 - x));
	double tmp;
	if ((1.0 - x) <= 1.0) {
		tmp = 1.0 + (t_0 + -1.0);
	} else {
		tmp = Math.PI - t_0;
	}
	return tmp;
}
def code(x):
	t_0 = math.acos((1.0 - x))
	tmp = 0
	if (1.0 - x) <= 1.0:
		tmp = 1.0 + (t_0 + -1.0)
	else:
		tmp = math.pi - t_0
	return tmp
function code(x)
	t_0 = acos(Float64(1.0 - x))
	tmp = 0.0
	if (Float64(1.0 - x) <= 1.0)
		tmp = Float64(1.0 + Float64(t_0 + -1.0));
	else
		tmp = Float64(pi - t_0);
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = acos((1.0 - x));
	tmp = 0.0;
	if ((1.0 - x) <= 1.0)
		tmp = 1.0 + (t_0 + -1.0);
	else
		tmp = pi - t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[N[(1.0 - x), $MachinePrecision], 1.0], N[(1.0 + N[(t$95$0 + -1.0), $MachinePrecision]), $MachinePrecision], N[(Pi - t$95$0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos^{-1} \left(1 - x\right)\\
\mathbf{if}\;1 - x \leq 1:\\
\;\;\;\;1 + \left(t_0 + -1\right)\\

\mathbf{else}:\\
\;\;\;\;\pi - t_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 1 x) < 1

    1. Initial program 7.1%

      \[\cos^{-1} \left(1 - x\right) \]
    2. Step-by-step derivation
      1. add-cbrt-cube7.1%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
      2. pow1/37.1%

        \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
      3. pow37.1%

        \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
    3. Applied egg-rr7.1%

      \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
    4. Step-by-step derivation
      1. unpow1/37.1%

        \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
      2. rem-cbrt-cube7.1%

        \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
      3. expm1-log1p-u7.1%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)\right)} \]
      4. expm1-udef7.1%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)} - 1} \]
      5. log1p-udef7.1%

        \[\leadsto e^{\color{blue}{\log \left(1 + \cos^{-1} \left(1 - x\right)\right)}} - 1 \]
      6. *-rgt-identity7.1%

        \[\leadsto e^{\log \color{blue}{\left(\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1\right)}} - 1 \]
      7. add-exp-log7.1%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1} - 1 \]
      8. *-rgt-identity7.1%

        \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right)} - 1 \]
      9. associate--l+7.1%

        \[\leadsto \color{blue}{1 + \left(\cos^{-1} \left(1 - x\right) - 1\right)} \]
      10. +-commutative7.1%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) - 1\right) + 1} \]
      11. sub-neg7.1%

        \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + \left(-1\right)\right)} + 1 \]
      12. metadata-eval7.1%

        \[\leadsto \left(\cos^{-1} \left(1 - x\right) + \color{blue}{-1}\right) + 1 \]
    5. Applied egg-rr7.1%

      \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) + 1} \]

    if 1 < (-.f64 1 x)

    1. Initial program 7.1%

      \[\cos^{-1} \left(1 - x\right) \]
    2. Step-by-step derivation
      1. add-cbrt-cube7.1%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
      2. pow1/37.1%

        \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
      3. pow37.1%

        \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
    3. Applied egg-rr7.1%

      \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
    4. Step-by-step derivation
      1. unpow1/37.1%

        \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
      2. rem-cbrt-cube7.1%

        \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
      3. acos-asin7.1%

        \[\leadsto \color{blue}{\frac{\pi}{2} - \sin^{-1} \left(1 - x\right)} \]
      4. div-inv7.1%

        \[\leadsto \color{blue}{\pi \cdot \frac{1}{2}} - \sin^{-1} \left(1 - x\right) \]
      5. metadata-eval7.1%

        \[\leadsto \pi \cdot \color{blue}{0.5} - \sin^{-1} \left(1 - x\right) \]
      6. sub-neg7.1%

        \[\leadsto \color{blue}{\pi \cdot 0.5 + \left(-\sin^{-1} \left(1 - x\right)\right)} \]
      7. +-commutative7.1%

        \[\leadsto \color{blue}{\left(-\sin^{-1} \left(1 - x\right)\right) + \pi \cdot 0.5} \]
      8. add-cube-cbrt10.7%

        \[\leadsto \left(-\color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right) + \pi \cdot 0.5 \]
      9. distribute-rgt-neg-in10.7%

        \[\leadsto \color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \left(-\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)} + \pi \cdot 0.5 \]
      10. fma-def10.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right)} \]
      11. pow210.7%

        \[\leadsto \mathsf{fma}\left(\color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
    5. Applied egg-rr10.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left({\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right)} \]
    6. Step-by-step derivation
      1. add-cube-cbrt10.7%

        \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
      2. unpow210.7%

        \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
      3. cbrt-prod10.7%

        \[\leadsto \mathsf{fma}\left({\color{blue}{\left(\sqrt[3]{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}} \cdot \sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
    7. Applied egg-rr10.7%

      \[\leadsto \mathsf{fma}\left({\color{blue}{\left(\sqrt[3]{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2}} \cdot \sqrt[3]{\sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
    8. Step-by-step derivation
      1. cbrt-unprod10.7%

        \[\leadsto \mathsf{fma}\left({\color{blue}{\left(\sqrt[3]{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
      2. unpow210.7%

        \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
      3. add-cube-cbrt10.7%

        \[\leadsto \mathsf{fma}\left({\left(\sqrt[3]{\color{blue}{\sin^{-1} \left(1 - x\right)}}\right)}^{2}, -\sqrt[3]{\sin^{-1} \left(1 - x\right)}, \pi \cdot 0.5\right) \]
      4. fma-def10.7%

        \[\leadsto \color{blue}{{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2} \cdot \left(-\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) + \pi \cdot 0.5} \]
      5. distribute-rgt-neg-in10.7%

        \[\leadsto \color{blue}{\left(-{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)}^{2} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)} + \pi \cdot 0.5 \]
      6. unpow210.7%

        \[\leadsto \left(-\color{blue}{\left(\sqrt[3]{\sin^{-1} \left(1 - x\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right)} \cdot \sqrt[3]{\sin^{-1} \left(1 - x\right)}\right) + \pi \cdot 0.5 \]
      7. add-cube-cbrt7.1%

        \[\leadsto \left(-\color{blue}{\sin^{-1} \left(1 - x\right)}\right) + \pi \cdot 0.5 \]
    9. Applied egg-rr6.9%

      \[\leadsto \color{blue}{\pi \cdot 0.5 - \left(\cos^{-1} \left(1 - x\right) - \pi \cdot 0.5\right)} \]
    10. Step-by-step derivation
      1. associate--r-6.9%

        \[\leadsto \color{blue}{\left(\pi \cdot 0.5 - \cos^{-1} \left(1 - x\right)\right) + \pi \cdot 0.5} \]
      2. +-commutative6.9%

        \[\leadsto \color{blue}{\pi \cdot 0.5 + \left(\pi \cdot 0.5 - \cos^{-1} \left(1 - x\right)\right)} \]
      3. associate--l+6.9%

        \[\leadsto \color{blue}{\left(\pi \cdot 0.5 + \pi \cdot 0.5\right) - \cos^{-1} \left(1 - x\right)} \]
      4. distribute-lft-out6.9%

        \[\leadsto \color{blue}{\pi \cdot \left(0.5 + 0.5\right)} - \cos^{-1} \left(1 - x\right) \]
      5. metadata-eval6.9%

        \[\leadsto \pi \cdot \color{blue}{1} - \cos^{-1} \left(1 - x\right) \]
      6. *-rgt-identity6.9%

        \[\leadsto \color{blue}{\pi} - \cos^{-1} \left(1 - x\right) \]
    11. Simplified6.9%

      \[\leadsto \color{blue}{\pi - \cos^{-1} \left(1 - x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification7.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;1 - x \leq 1:\\ \;\;\;\;1 + \left(\cos^{-1} \left(1 - x\right) + -1\right)\\ \mathbf{else}:\\ \;\;\;\;\pi - \cos^{-1} \left(1 - x\right)\\ \end{array} \]

Alternative 12: 6.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 1 + \left(\cos^{-1} \left(1 - x\right) + -1\right) \end{array} \]
(FPCore (x) :precision binary64 (+ 1.0 (+ (acos (- 1.0 x)) -1.0)))
double code(double x) {
	return 1.0 + (acos((1.0 - x)) + -1.0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.0d0 + (acos((1.0d0 - x)) + (-1.0d0))
end function
public static double code(double x) {
	return 1.0 + (Math.acos((1.0 - x)) + -1.0);
}
def code(x):
	return 1.0 + (math.acos((1.0 - x)) + -1.0)
function code(x)
	return Float64(1.0 + Float64(acos(Float64(1.0 - x)) + -1.0))
end
function tmp = code(x)
	tmp = 1.0 + (acos((1.0 - x)) + -1.0);
end
code[x_] := N[(1.0 + N[(N[ArcCos[N[(1.0 - x), $MachinePrecision]], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 + \left(\cos^{-1} \left(1 - x\right) + -1\right)
\end{array}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Step-by-step derivation
    1. add-cbrt-cube7.1%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)}} \]
    2. pow1/37.1%

      \[\leadsto \color{blue}{{\left(\left(\cos^{-1} \left(1 - x\right) \cdot \cos^{-1} \left(1 - x\right)\right) \cdot \cos^{-1} \left(1 - x\right)\right)}^{0.3333333333333333}} \]
    3. pow37.1%

      \[\leadsto {\color{blue}{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}}^{0.3333333333333333} \]
  3. Applied egg-rr7.1%

    \[\leadsto \color{blue}{{\left({\cos^{-1} \left(1 - x\right)}^{3}\right)}^{0.3333333333333333}} \]
  4. Step-by-step derivation
    1. unpow1/37.1%

      \[\leadsto \color{blue}{\sqrt[3]{{\cos^{-1} \left(1 - x\right)}^{3}}} \]
    2. rem-cbrt-cube7.1%

      \[\leadsto \color{blue}{\cos^{-1} \left(1 - x\right)} \]
    3. expm1-log1p-u7.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)\right)} \]
    4. expm1-udef7.1%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\cos^{-1} \left(1 - x\right)\right)} - 1} \]
    5. log1p-udef7.1%

      \[\leadsto e^{\color{blue}{\log \left(1 + \cos^{-1} \left(1 - x\right)\right)}} - 1 \]
    6. *-rgt-identity7.1%

      \[\leadsto e^{\log \color{blue}{\left(\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1\right)}} - 1 \]
    7. add-exp-log7.1%

      \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right) \cdot 1} - 1 \]
    8. *-rgt-identity7.1%

      \[\leadsto \color{blue}{\left(1 + \cos^{-1} \left(1 - x\right)\right)} - 1 \]
    9. associate--l+7.1%

      \[\leadsto \color{blue}{1 + \left(\cos^{-1} \left(1 - x\right) - 1\right)} \]
    10. +-commutative7.1%

      \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) - 1\right) + 1} \]
    11. sub-neg7.1%

      \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + \left(-1\right)\right)} + 1 \]
    12. metadata-eval7.1%

      \[\leadsto \left(\cos^{-1} \left(1 - x\right) + \color{blue}{-1}\right) + 1 \]
  5. Applied egg-rr7.1%

    \[\leadsto \color{blue}{\left(\cos^{-1} \left(1 - x\right) + -1\right) + 1} \]
  6. Final simplification7.1%

    \[\leadsto 1 + \left(\cos^{-1} \left(1 - x\right) + -1\right) \]

Alternative 13: 6.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \cos^{-1} \left(1 - x\right) \end{array} \]
(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}
Derivation
  1. Initial program 7.1%

    \[\cos^{-1} \left(1 - x\right) \]
  2. Final simplification7.1%

    \[\leadsto \cos^{-1} \left(1 - x\right) \]

Developer target: 100.0% accurate, 0.5× speedup?

\[\begin{array}{l} \\ 2 \cdot \sin^{-1} \left(\sqrt{\frac{x}{2}}\right) \end{array} \]
(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}

Reproduce

?
herbie shell --seed 2023173 
(FPCore (x)
  :name "bug323 (missed optimization)"
  :precision binary64
  :pre (and (<= 0.0 x) (<= x 0.5))

  :herbie-target
  (* 2.0 (asin (sqrt (/ x 2.0))))

  (acos (- 1.0 x)))