Given's Rotation SVD example, simplified

Percentage Accurate: 76.3% → 99.8%
Time: 13.6s
Alternatives: 13
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ 1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))
double code(double x) {
	return 1.0 - sqrt((0.5 * (1.0 + (1.0 / hypot(1.0, x)))));
}
public static double code(double x) {
	return 1.0 - Math.sqrt((0.5 * (1.0 + (1.0 / Math.hypot(1.0, x)))));
}
def code(x):
	return 1.0 - math.sqrt((0.5 * (1.0 + (1.0 / math.hypot(1.0, x)))))
function code(x)
	return Float64(1.0 - sqrt(Float64(0.5 * Float64(1.0 + Float64(1.0 / hypot(1.0, x))))))
end
function tmp = code(x)
	tmp = 1.0 - sqrt((0.5 * (1.0 + (1.0 / hypot(1.0, x)))));
end
code[x_] := N[(1.0 - N[Sqrt[N[(0.5 * N[(1.0 + N[(1.0 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\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: 76.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))
double code(double x) {
	return 1.0 - sqrt((0.5 * (1.0 + (1.0 / hypot(1.0, x)))));
}
public static double code(double x) {
	return 1.0 - Math.sqrt((0.5 * (1.0 + (1.0 / Math.hypot(1.0, x)))));
}
def code(x):
	return 1.0 - math.sqrt((0.5 * (1.0 + (1.0 / math.hypot(1.0, x)))))
function code(x)
	return Float64(1.0 - sqrt(Float64(0.5 * Float64(1.0 + Float64(1.0 / hypot(1.0, x))))))
end
function tmp = code(x)
	tmp = 1.0 - sqrt((0.5 * (1.0 + (1.0 / hypot(1.0, x)))));
end
code[x_] := N[(1.0 - N[Sqrt[N[(0.5 * N[(1.0 + N[(1.0 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)}
\end{array}

Alternative 1: 99.8% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\\ \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.0673828125 + {x}^{2} \cdot -0.056243896484375\right) - 0.0859375\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - t\_0}{1 + {\left({\left(0.5 + t\_0\right)}^{0.25}\right)}^{2}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ 0.5 (hypot 1.0 x))))
   (if (<= (hypot 1.0 x) 2.0)
     (*
      (pow x 2.0)
      (+
       0.125
       (*
        (pow x 2.0)
        (-
         (* (pow x 2.0) (+ 0.0673828125 (* (pow x 2.0) -0.056243896484375)))
         0.0859375))))
     (/ (- 0.5 t_0) (+ 1.0 (pow (pow (+ 0.5 t_0) 0.25) 2.0))))))
double code(double x) {
	double t_0 = 0.5 / hypot(1.0, x);
	double tmp;
	if (hypot(1.0, x) <= 2.0) {
		tmp = pow(x, 2.0) * (0.125 + (pow(x, 2.0) * ((pow(x, 2.0) * (0.0673828125 + (pow(x, 2.0) * -0.056243896484375))) - 0.0859375)));
	} else {
		tmp = (0.5 - t_0) / (1.0 + pow(pow((0.5 + t_0), 0.25), 2.0));
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = 0.5 / Math.hypot(1.0, x);
	double tmp;
	if (Math.hypot(1.0, x) <= 2.0) {
		tmp = Math.pow(x, 2.0) * (0.125 + (Math.pow(x, 2.0) * ((Math.pow(x, 2.0) * (0.0673828125 + (Math.pow(x, 2.0) * -0.056243896484375))) - 0.0859375)));
	} else {
		tmp = (0.5 - t_0) / (1.0 + Math.pow(Math.pow((0.5 + t_0), 0.25), 2.0));
	}
	return tmp;
}
def code(x):
	t_0 = 0.5 / math.hypot(1.0, x)
	tmp = 0
	if math.hypot(1.0, x) <= 2.0:
		tmp = math.pow(x, 2.0) * (0.125 + (math.pow(x, 2.0) * ((math.pow(x, 2.0) * (0.0673828125 + (math.pow(x, 2.0) * -0.056243896484375))) - 0.0859375)))
	else:
		tmp = (0.5 - t_0) / (1.0 + math.pow(math.pow((0.5 + t_0), 0.25), 2.0))
	return tmp
function code(x)
	t_0 = Float64(0.5 / hypot(1.0, x))
	tmp = 0.0
	if (hypot(1.0, x) <= 2.0)
		tmp = Float64((x ^ 2.0) * Float64(0.125 + Float64((x ^ 2.0) * Float64(Float64((x ^ 2.0) * Float64(0.0673828125 + Float64((x ^ 2.0) * -0.056243896484375))) - 0.0859375))));
	else
		tmp = Float64(Float64(0.5 - t_0) / Float64(1.0 + ((Float64(0.5 + t_0) ^ 0.25) ^ 2.0)));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = 0.5 / hypot(1.0, x);
	tmp = 0.0;
	if (hypot(1.0, x) <= 2.0)
		tmp = (x ^ 2.0) * (0.125 + ((x ^ 2.0) * (((x ^ 2.0) * (0.0673828125 + ((x ^ 2.0) * -0.056243896484375))) - 0.0859375)));
	else
		tmp = (0.5 - t_0) / (1.0 + (((0.5 + t_0) ^ 0.25) ^ 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 2.0], N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.125 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.0673828125 + N[(N[Power[x, 2.0], $MachinePrecision] * -0.056243896484375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 0.0859375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 - t$95$0), $MachinePrecision] / N[(1.0 + N[Power[N[Power[N[(0.5 + t$95$0), $MachinePrecision], 0.25], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\\
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\
\;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.0673828125 + {x}^{2} \cdot -0.056243896484375\right) - 0.0859375\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5 - t\_0}{1 + {\left({\left(0.5 + t\_0\right)}^{0.25}\right)}^{2}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (hypot.f64 #s(literal 1 binary64) x) < 2

    1. Initial program 52.8%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in52.8%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval52.8%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/52.8%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval52.8%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified52.8%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.0673828125 + -0.056243896484375 \cdot {x}^{2}\right) - 0.0859375\right)\right)} \]

    if 2 < (hypot.f64 #s(literal 1 binary64) x)

    1. Initial program 98.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--98.5%

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
      2. metadata-eval98.5%

        \[\leadsto \frac{\color{blue}{1} - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      3. add-sqr-sqrt100.0%

        \[\leadsto \frac{1 - \color{blue}{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. associate--r+100.0%

        \[\leadsto \frac{\color{blue}{\left(1 - 0.5\right) - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      5. metadata-eval100.0%

        \[\leadsto \frac{\color{blue}{0.5} - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    6. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
    7. Step-by-step derivation
      1. add-sqr-sqrt98.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{\sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \cdot \sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}}} \]
      2. pow298.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{{\left(\sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}\right)}^{2}}} \]
      3. pow1/298.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left(\sqrt{\color{blue}{{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.5}}}\right)}^{2}} \]
      4. sqrt-pow1100.0%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\color{blue}{\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{\left(\frac{0.5}{2}\right)}\right)}}^{2}} \]
      5. metadata-eval100.0%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{\color{blue}{0.25}}\right)}^{2}} \]
    8. Applied egg-rr100.0%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{{\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.25}\right)}^{2}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.0673828125 + {x}^{2} \cdot -0.056243896484375\right) - 0.0859375\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.25}\right)}^{2}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\\ \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - t\_0}{1 + {\left({\left(0.5 + t\_0\right)}^{0.25}\right)}^{2}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ 0.5 (hypot 1.0 x))))
   (if (<= (hypot 1.0 x) 1.00005)
     (* (pow x 2.0) (+ 0.125 (* (pow x 2.0) -0.0859375)))
     (/ (- 0.5 t_0) (+ 1.0 (pow (pow (+ 0.5 t_0) 0.25) 2.0))))))
double code(double x) {
	double t_0 = 0.5 / hypot(1.0, x);
	double tmp;
	if (hypot(1.0, x) <= 1.00005) {
		tmp = pow(x, 2.0) * (0.125 + (pow(x, 2.0) * -0.0859375));
	} else {
		tmp = (0.5 - t_0) / (1.0 + pow(pow((0.5 + t_0), 0.25), 2.0));
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = 0.5 / Math.hypot(1.0, x);
	double tmp;
	if (Math.hypot(1.0, x) <= 1.00005) {
		tmp = Math.pow(x, 2.0) * (0.125 + (Math.pow(x, 2.0) * -0.0859375));
	} else {
		tmp = (0.5 - t_0) / (1.0 + Math.pow(Math.pow((0.5 + t_0), 0.25), 2.0));
	}
	return tmp;
}
def code(x):
	t_0 = 0.5 / math.hypot(1.0, x)
	tmp = 0
	if math.hypot(1.0, x) <= 1.00005:
		tmp = math.pow(x, 2.0) * (0.125 + (math.pow(x, 2.0) * -0.0859375))
	else:
		tmp = (0.5 - t_0) / (1.0 + math.pow(math.pow((0.5 + t_0), 0.25), 2.0))
	return tmp
function code(x)
	t_0 = Float64(0.5 / hypot(1.0, x))
	tmp = 0.0
	if (hypot(1.0, x) <= 1.00005)
		tmp = Float64((x ^ 2.0) * Float64(0.125 + Float64((x ^ 2.0) * -0.0859375)));
	else
		tmp = Float64(Float64(0.5 - t_0) / Float64(1.0 + ((Float64(0.5 + t_0) ^ 0.25) ^ 2.0)));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = 0.5 / hypot(1.0, x);
	tmp = 0.0;
	if (hypot(1.0, x) <= 1.00005)
		tmp = (x ^ 2.0) * (0.125 + ((x ^ 2.0) * -0.0859375));
	else
		tmp = (0.5 - t_0) / (1.0 + (((0.5 + t_0) ^ 0.25) ^ 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 1.00005], N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.125 + N[(N[Power[x, 2.0], $MachinePrecision] * -0.0859375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 - t$95$0), $MachinePrecision] / N[(1.0 + N[Power[N[Power[N[(0.5 + t$95$0), $MachinePrecision], 0.25], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\\
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\
\;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5 - t\_0}{1 + {\left({\left(0.5 + t\_0\right)}^{0.25}\right)}^{2}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (hypot.f64 #s(literal 1 binary64) x) < 1.00005000000000011

    1. Initial program 52.6%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in52.6%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval52.6%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/52.6%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval52.6%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified52.6%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + -0.0859375 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(0.125 + \color{blue}{{x}^{2} \cdot -0.0859375}\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)} \]

    if 1.00005000000000011 < (hypot.f64 #s(literal 1 binary64) x)

    1. Initial program 98.3%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.3%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.3%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.3%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.3%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.3%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--98.3%

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
      2. metadata-eval98.3%

        \[\leadsto \frac{\color{blue}{1} - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      3. add-sqr-sqrt99.8%

        \[\leadsto \frac{1 - \color{blue}{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. associate--r+99.8%

        \[\leadsto \frac{\color{blue}{\left(1 - 0.5\right) - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      5. metadata-eval99.8%

        \[\leadsto \frac{\color{blue}{0.5} - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    6. Applied egg-rr99.8%

      \[\leadsto \color{blue}{\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
    7. Step-by-step derivation
      1. add-sqr-sqrt98.4%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{\sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \cdot \sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}}} \]
      2. pow298.4%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{{\left(\sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}\right)}^{2}}} \]
      3. pow1/298.4%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left(\sqrt{\color{blue}{{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.5}}}\right)}^{2}} \]
      4. sqrt-pow199.8%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\color{blue}{\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{\left(\frac{0.5}{2}\right)}\right)}}^{2}} \]
      5. metadata-eval99.8%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{\color{blue}{0.25}}\right)}^{2}} \]
    8. Applied egg-rr99.8%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{{\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.25}\right)}^{2}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.25}\right)}^{2}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.9% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\\ \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - t\_0}{1 + \sqrt{0.5 + t\_0}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ 0.5 (hypot 1.0 x))))
   (if (<= (hypot 1.0 x) 1.00005)
     (* (pow x 2.0) (+ 0.125 (* (pow x 2.0) -0.0859375)))
     (/ (- 0.5 t_0) (+ 1.0 (sqrt (+ 0.5 t_0)))))))
double code(double x) {
	double t_0 = 0.5 / hypot(1.0, x);
	double tmp;
	if (hypot(1.0, x) <= 1.00005) {
		tmp = pow(x, 2.0) * (0.125 + (pow(x, 2.0) * -0.0859375));
	} else {
		tmp = (0.5 - t_0) / (1.0 + sqrt((0.5 + t_0)));
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = 0.5 / Math.hypot(1.0, x);
	double tmp;
	if (Math.hypot(1.0, x) <= 1.00005) {
		tmp = Math.pow(x, 2.0) * (0.125 + (Math.pow(x, 2.0) * -0.0859375));
	} else {
		tmp = (0.5 - t_0) / (1.0 + Math.sqrt((0.5 + t_0)));
	}
	return tmp;
}
def code(x):
	t_0 = 0.5 / math.hypot(1.0, x)
	tmp = 0
	if math.hypot(1.0, x) <= 1.00005:
		tmp = math.pow(x, 2.0) * (0.125 + (math.pow(x, 2.0) * -0.0859375))
	else:
		tmp = (0.5 - t_0) / (1.0 + math.sqrt((0.5 + t_0)))
	return tmp
function code(x)
	t_0 = Float64(0.5 / hypot(1.0, x))
	tmp = 0.0
	if (hypot(1.0, x) <= 1.00005)
		tmp = Float64((x ^ 2.0) * Float64(0.125 + Float64((x ^ 2.0) * -0.0859375)));
	else
		tmp = Float64(Float64(0.5 - t_0) / Float64(1.0 + sqrt(Float64(0.5 + t_0))));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = 0.5 / hypot(1.0, x);
	tmp = 0.0;
	if (hypot(1.0, x) <= 1.00005)
		tmp = (x ^ 2.0) * (0.125 + ((x ^ 2.0) * -0.0859375));
	else
		tmp = (0.5 - t_0) / (1.0 + sqrt((0.5 + t_0)));
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 1.00005], N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.125 + N[(N[Power[x, 2.0], $MachinePrecision] * -0.0859375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 - t$95$0), $MachinePrecision] / N[(1.0 + N[Sqrt[N[(0.5 + t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\\
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\
\;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5 - t\_0}{1 + \sqrt{0.5 + t\_0}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (hypot.f64 #s(literal 1 binary64) x) < 1.00005000000000011

    1. Initial program 52.6%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in52.6%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval52.6%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/52.6%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval52.6%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified52.6%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + -0.0859375 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(0.125 + \color{blue}{{x}^{2} \cdot -0.0859375}\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)} \]

    if 1.00005000000000011 < (hypot.f64 #s(literal 1 binary64) x)

    1. Initial program 98.3%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.3%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.3%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.3%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.3%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.3%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--98.3%

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
      2. metadata-eval98.3%

        \[\leadsto \frac{\color{blue}{1} - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      3. add-sqr-sqrt99.8%

        \[\leadsto \frac{1 - \color{blue}{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. associate--r+99.8%

        \[\leadsto \frac{\color{blue}{\left(1 - 0.5\right) - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      5. metadata-eval99.8%

        \[\leadsto \frac{\color{blue}{0.5} - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    6. Applied egg-rr99.8%

      \[\leadsto \color{blue}{\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot \left({x}^{2} \cdot 0.0673828125 - 0.0859375\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - \frac{0.5}{x}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (hypot 1.0 x) 2.0)
   (*
    (pow x 2.0)
    (+ 0.125 (* (pow x 2.0) (- (* (pow x 2.0) 0.0673828125) 0.0859375))))
   (/ (- 0.5 (/ 0.5 x)) (+ 1.0 (pow (pow (+ 0.5 (/ 0.5 x)) 0.25) 2.0)))))
double code(double x) {
	double tmp;
	if (hypot(1.0, x) <= 2.0) {
		tmp = pow(x, 2.0) * (0.125 + (pow(x, 2.0) * ((pow(x, 2.0) * 0.0673828125) - 0.0859375)));
	} else {
		tmp = (0.5 - (0.5 / x)) / (1.0 + pow(pow((0.5 + (0.5 / x)), 0.25), 2.0));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (Math.hypot(1.0, x) <= 2.0) {
		tmp = Math.pow(x, 2.0) * (0.125 + (Math.pow(x, 2.0) * ((Math.pow(x, 2.0) * 0.0673828125) - 0.0859375)));
	} else {
		tmp = (0.5 - (0.5 / x)) / (1.0 + Math.pow(Math.pow((0.5 + (0.5 / x)), 0.25), 2.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if math.hypot(1.0, x) <= 2.0:
		tmp = math.pow(x, 2.0) * (0.125 + (math.pow(x, 2.0) * ((math.pow(x, 2.0) * 0.0673828125) - 0.0859375)))
	else:
		tmp = (0.5 - (0.5 / x)) / (1.0 + math.pow(math.pow((0.5 + (0.5 / x)), 0.25), 2.0))
	return tmp
function code(x)
	tmp = 0.0
	if (hypot(1.0, x) <= 2.0)
		tmp = Float64((x ^ 2.0) * Float64(0.125 + Float64((x ^ 2.0) * Float64(Float64((x ^ 2.0) * 0.0673828125) - 0.0859375))));
	else
		tmp = Float64(Float64(0.5 - Float64(0.5 / x)) / Float64(1.0 + ((Float64(0.5 + Float64(0.5 / x)) ^ 0.25) ^ 2.0)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (hypot(1.0, x) <= 2.0)
		tmp = (x ^ 2.0) * (0.125 + ((x ^ 2.0) * (((x ^ 2.0) * 0.0673828125) - 0.0859375)));
	else
		tmp = (0.5 - (0.5 / x)) / (1.0 + (((0.5 + (0.5 / x)) ^ 0.25) ^ 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 2.0], N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.125 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(N[Power[x, 2.0], $MachinePrecision] * 0.0673828125), $MachinePrecision] - 0.0859375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 - N[(0.5 / x), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Power[N[Power[N[(0.5 + N[(0.5 / x), $MachinePrecision]), $MachinePrecision], 0.25], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\
\;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot \left({x}^{2} \cdot 0.0673828125 - 0.0859375\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5 - \frac{0.5}{x}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (hypot.f64 #s(literal 1 binary64) x) < 2

    1. Initial program 52.8%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in52.8%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval52.8%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/52.8%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval52.8%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified52.8%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 99.8%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot \left(0.0673828125 \cdot {x}^{2} - 0.0859375\right)\right)} \]

    if 2 < (hypot.f64 #s(literal 1 binary64) x)

    1. Initial program 98.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--98.5%

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
      2. metadata-eval98.5%

        \[\leadsto \frac{\color{blue}{1} - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      3. add-sqr-sqrt100.0%

        \[\leadsto \frac{1 - \color{blue}{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. associate--r+100.0%

        \[\leadsto \frac{\color{blue}{\left(1 - 0.5\right) - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      5. metadata-eval100.0%

        \[\leadsto \frac{\color{blue}{0.5} - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    6. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
    7. Step-by-step derivation
      1. add-sqr-sqrt98.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{\sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \cdot \sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}}} \]
      2. pow298.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{{\left(\sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}\right)}^{2}}} \]
      3. pow1/298.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left(\sqrt{\color{blue}{{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.5}}}\right)}^{2}} \]
      4. sqrt-pow1100.0%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\color{blue}{\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{\left(\frac{0.5}{2}\right)}\right)}}^{2}} \]
      5. metadata-eval100.0%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{\color{blue}{0.25}}\right)}^{2}} \]
    8. Applied egg-rr100.0%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{{\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.25}\right)}^{2}}} \]
    9. Taylor expanded in x around inf 98.4%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\color{blue}{\left(0.5 + 0.5 \cdot \frac{1}{x}\right)}}^{0.25}\right)}^{2}} \]
    10. Step-by-step derivation
      1. associate-*r/96.8%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{x}}} \]
      2. metadata-eval96.8%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{x}} \]
    11. Simplified98.4%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\color{blue}{\left(0.5 + \frac{0.5}{x}\right)}}^{0.25}\right)}^{2}} \]
    12. Taylor expanded in x around inf 98.2%

      \[\leadsto \frac{\color{blue}{0.5 - 0.5 \cdot \frac{1}{x}}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}} \]
    13. Step-by-step derivation
      1. associate-*r/98.2%

        \[\leadsto \frac{0.5 - \color{blue}{\frac{0.5 \cdot 1}{x}}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}} \]
      2. metadata-eval98.2%

        \[\leadsto \frac{0.5 - \frac{\color{blue}{0.5}}{x}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}} \]
    14. Simplified98.2%

      \[\leadsto \frac{\color{blue}{0.5 - \frac{0.5}{x}}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot \left({x}^{2} \cdot 0.0673828125 - 0.0859375\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - \frac{0.5}{x}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.0% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - \frac{0.5}{x}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (hypot 1.0 x) 2.0)
   (* (pow x 2.0) (+ 0.125 (* (pow x 2.0) -0.0859375)))
   (/ (- 0.5 (/ 0.5 x)) (+ 1.0 (pow (pow (+ 0.5 (/ 0.5 x)) 0.25) 2.0)))))
double code(double x) {
	double tmp;
	if (hypot(1.0, x) <= 2.0) {
		tmp = pow(x, 2.0) * (0.125 + (pow(x, 2.0) * -0.0859375));
	} else {
		tmp = (0.5 - (0.5 / x)) / (1.0 + pow(pow((0.5 + (0.5 / x)), 0.25), 2.0));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (Math.hypot(1.0, x) <= 2.0) {
		tmp = Math.pow(x, 2.0) * (0.125 + (Math.pow(x, 2.0) * -0.0859375));
	} else {
		tmp = (0.5 - (0.5 / x)) / (1.0 + Math.pow(Math.pow((0.5 + (0.5 / x)), 0.25), 2.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if math.hypot(1.0, x) <= 2.0:
		tmp = math.pow(x, 2.0) * (0.125 + (math.pow(x, 2.0) * -0.0859375))
	else:
		tmp = (0.5 - (0.5 / x)) / (1.0 + math.pow(math.pow((0.5 + (0.5 / x)), 0.25), 2.0))
	return tmp
function code(x)
	tmp = 0.0
	if (hypot(1.0, x) <= 2.0)
		tmp = Float64((x ^ 2.0) * Float64(0.125 + Float64((x ^ 2.0) * -0.0859375)));
	else
		tmp = Float64(Float64(0.5 - Float64(0.5 / x)) / Float64(1.0 + ((Float64(0.5 + Float64(0.5 / x)) ^ 0.25) ^ 2.0)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (hypot(1.0, x) <= 2.0)
		tmp = (x ^ 2.0) * (0.125 + ((x ^ 2.0) * -0.0859375));
	else
		tmp = (0.5 - (0.5 / x)) / (1.0 + (((0.5 + (0.5 / x)) ^ 0.25) ^ 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 2.0], N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.125 + N[(N[Power[x, 2.0], $MachinePrecision] * -0.0859375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 - N[(0.5 / x), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Power[N[Power[N[(0.5 + N[(0.5 / x), $MachinePrecision]), $MachinePrecision], 0.25], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\
\;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5 - \frac{0.5}{x}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (hypot.f64 #s(literal 1 binary64) x) < 2

    1. Initial program 52.8%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in52.8%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval52.8%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/52.8%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval52.8%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified52.8%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 99.7%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + -0.0859375 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative99.7%

        \[\leadsto {x}^{2} \cdot \left(0.125 + \color{blue}{{x}^{2} \cdot -0.0859375}\right) \]
    7. Simplified99.7%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)} \]

    if 2 < (hypot.f64 #s(literal 1 binary64) x)

    1. Initial program 98.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--98.5%

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
      2. metadata-eval98.5%

        \[\leadsto \frac{\color{blue}{1} - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      3. add-sqr-sqrt100.0%

        \[\leadsto \frac{1 - \color{blue}{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. associate--r+100.0%

        \[\leadsto \frac{\color{blue}{\left(1 - 0.5\right) - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      5. metadata-eval100.0%

        \[\leadsto \frac{\color{blue}{0.5} - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    6. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
    7. Step-by-step derivation
      1. add-sqr-sqrt98.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{\sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \cdot \sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}}} \]
      2. pow298.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{{\left(\sqrt{\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}\right)}^{2}}} \]
      3. pow1/298.5%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left(\sqrt{\color{blue}{{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.5}}}\right)}^{2}} \]
      4. sqrt-pow1100.0%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\color{blue}{\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{\left(\frac{0.5}{2}\right)}\right)}}^{2}} \]
      5. metadata-eval100.0%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{\color{blue}{0.25}}\right)}^{2}} \]
    8. Applied egg-rr100.0%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \color{blue}{{\left({\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{0.25}\right)}^{2}}} \]
    9. Taylor expanded in x around inf 98.4%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\color{blue}{\left(0.5 + 0.5 \cdot \frac{1}{x}\right)}}^{0.25}\right)}^{2}} \]
    10. Step-by-step derivation
      1. associate-*r/96.8%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{x}}} \]
      2. metadata-eval96.8%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{x}} \]
    11. Simplified98.4%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + {\left({\color{blue}{\left(0.5 + \frac{0.5}{x}\right)}}^{0.25}\right)}^{2}} \]
    12. Taylor expanded in x around inf 98.2%

      \[\leadsto \frac{\color{blue}{0.5 - 0.5 \cdot \frac{1}{x}}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}} \]
    13. Step-by-step derivation
      1. associate-*r/98.2%

        \[\leadsto \frac{0.5 - \color{blue}{\frac{0.5 \cdot 1}{x}}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}} \]
      2. metadata-eval98.2%

        \[\leadsto \frac{0.5 - \frac{\color{blue}{0.5}}{x}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}} \]
    14. Simplified98.2%

      \[\leadsto \frac{\color{blue}{0.5 - \frac{0.5}{x}}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 - \frac{0.5}{x}}{1 + {\left({\left(0.5 + \frac{0.5}{x}\right)}^{0.25}\right)}^{2}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 99.1% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (hypot 1.0 x) 1.00005)
   (* (pow x 2.0) (+ 0.125 (* (pow x 2.0) -0.0859375)))
   (- 1.0 (sqrt (+ 0.5 (/ 0.5 (hypot 1.0 x)))))))
double code(double x) {
	double tmp;
	if (hypot(1.0, x) <= 1.00005) {
		tmp = pow(x, 2.0) * (0.125 + (pow(x, 2.0) * -0.0859375));
	} else {
		tmp = 1.0 - sqrt((0.5 + (0.5 / hypot(1.0, x))));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (Math.hypot(1.0, x) <= 1.00005) {
		tmp = Math.pow(x, 2.0) * (0.125 + (Math.pow(x, 2.0) * -0.0859375));
	} else {
		tmp = 1.0 - Math.sqrt((0.5 + (0.5 / Math.hypot(1.0, x))));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if math.hypot(1.0, x) <= 1.00005:
		tmp = math.pow(x, 2.0) * (0.125 + (math.pow(x, 2.0) * -0.0859375))
	else:
		tmp = 1.0 - math.sqrt((0.5 + (0.5 / math.hypot(1.0, x))))
	return tmp
function code(x)
	tmp = 0.0
	if (hypot(1.0, x) <= 1.00005)
		tmp = Float64((x ^ 2.0) * Float64(0.125 + Float64((x ^ 2.0) * -0.0859375)));
	else
		tmp = Float64(1.0 - sqrt(Float64(0.5 + Float64(0.5 / hypot(1.0, x)))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (hypot(1.0, x) <= 1.00005)
		tmp = (x ^ 2.0) * (0.125 + ((x ^ 2.0) * -0.0859375));
	else
		tmp = 1.0 - sqrt((0.5 + (0.5 / hypot(1.0, x))));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 1.00005], N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.125 + N[(N[Power[x, 2.0], $MachinePrecision] * -0.0859375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Sqrt[N[(0.5 + N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\
\;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (hypot.f64 #s(literal 1 binary64) x) < 1.00005000000000011

    1. Initial program 52.6%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in52.6%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval52.6%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/52.6%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval52.6%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified52.6%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + -0.0859375 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(0.125 + \color{blue}{{x}^{2} \cdot -0.0859375}\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)} \]

    if 1.00005000000000011 < (hypot.f64 #s(literal 1 binary64) x)

    1. Initial program 98.3%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.3%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.3%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.3%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.3%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.3%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\ \;\;\;\;{x}^{2} \cdot \left(0.125 + {x}^{2} \cdot -0.0859375\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 98.9% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (hypot 1.0 x) 1.00005)
   (* 0.125 (* x x))
   (- 1.0 (sqrt (+ 0.5 (/ 0.5 (hypot 1.0 x)))))))
double code(double x) {
	double tmp;
	if (hypot(1.0, x) <= 1.00005) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 1.0 - sqrt((0.5 + (0.5 / hypot(1.0, x))));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (Math.hypot(1.0, x) <= 1.00005) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 1.0 - Math.sqrt((0.5 + (0.5 / Math.hypot(1.0, x))));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if math.hypot(1.0, x) <= 1.00005:
		tmp = 0.125 * (x * x)
	else:
		tmp = 1.0 - math.sqrt((0.5 + (0.5 / math.hypot(1.0, x))))
	return tmp
function code(x)
	tmp = 0.0
	if (hypot(1.0, x) <= 1.00005)
		tmp = Float64(0.125 * Float64(x * x));
	else
		tmp = Float64(1.0 - sqrt(Float64(0.5 + Float64(0.5 / hypot(1.0, x)))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (hypot(1.0, x) <= 1.00005)
		tmp = 0.125 * (x * x);
	else
		tmp = 1.0 - sqrt((0.5 + (0.5 / hypot(1.0, x))));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 1.00005], N[(0.125 * N[(x * x), $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Sqrt[N[(0.5 + N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\
\;\;\;\;0.125 \cdot \left(x \cdot x\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (hypot.f64 #s(literal 1 binary64) x) < 1.00005000000000011

    1. Initial program 52.6%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in52.6%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval52.6%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/52.6%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval52.6%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified52.6%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 52.7%

      \[\leadsto 1 - \color{blue}{\left(1 + -0.125 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative52.7%

        \[\leadsto 1 - \left(1 + \color{blue}{{x}^{2} \cdot -0.125}\right) \]
    7. Simplified52.7%

      \[\leadsto 1 - \color{blue}{\left(1 + {x}^{2} \cdot -0.125\right)} \]
    8. Step-by-step derivation
      1. associate--r+99.8%

        \[\leadsto \color{blue}{\left(1 - 1\right) - {x}^{2} \cdot -0.125} \]
      2. metadata-eval99.8%

        \[\leadsto \color{blue}{0} - {x}^{2} \cdot -0.125 \]
      3. flip--33.8%

        \[\leadsto \color{blue}{\frac{0 \cdot 0 - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125}} \]
      4. metadata-eval33.8%

        \[\leadsto \frac{\color{blue}{0} - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      5. swap-sqr33.8%

        \[\leadsto \frac{0 - \color{blue}{\left({x}^{2} \cdot {x}^{2}\right) \cdot \left(-0.125 \cdot -0.125\right)}}{0 + {x}^{2} \cdot -0.125} \]
      6. pow-prod-up33.6%

        \[\leadsto \frac{0 - \color{blue}{{x}^{\left(2 + 2\right)}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      7. metadata-eval33.6%

        \[\leadsto \frac{0 - {x}^{\color{blue}{4}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      8. metadata-eval33.6%

        \[\leadsto \frac{0 - {x}^{4} \cdot \color{blue}{0.015625}}{0 + {x}^{2} \cdot -0.125} \]
    9. Applied egg-rr33.6%

      \[\leadsto \color{blue}{\frac{0 - {x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
    10. Step-by-step derivation
      1. div-sub33.6%

        \[\leadsto \color{blue}{\frac{0}{0 + {x}^{2} \cdot -0.125} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      2. +-lft-identity33.6%

        \[\leadsto \frac{0}{\color{blue}{{x}^{2} \cdot -0.125}} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      3. div033.6%

        \[\leadsto \color{blue}{0} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      4. neg-sub033.6%

        \[\leadsto \color{blue}{-\frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      5. *-commutative33.6%

        \[\leadsto -\frac{\color{blue}{0.015625 \cdot {x}^{4}}}{0 + {x}^{2} \cdot -0.125} \]
      6. +-lft-identity33.6%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{{x}^{2} \cdot -0.125}} \]
      7. *-commutative33.6%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{-0.125 \cdot {x}^{2}}} \]
      8. times-frac33.7%

        \[\leadsto -\color{blue}{\frac{0.015625}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      9. metadata-eval33.7%

        \[\leadsto -\color{blue}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
      10. distribute-lft-neg-in33.7%

        \[\leadsto \color{blue}{\left(--0.125\right) \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      11. metadata-eval33.7%

        \[\leadsto \color{blue}{0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
    11. Simplified33.7%

      \[\leadsto \color{blue}{0.125 \cdot \frac{{x}^{4}}{{x}^{2}}} \]
    12. Step-by-step derivation
      1. pow-div99.8%

        \[\leadsto 0.125 \cdot \color{blue}{{x}^{\left(4 - 2\right)}} \]
      2. metadata-eval99.8%

        \[\leadsto 0.125 \cdot {x}^{\color{blue}{2}} \]
      3. unpow299.8%

        \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]
    13. Applied egg-rr99.8%

      \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]

    if 1.00005000000000011 < (hypot.f64 #s(literal 1 binary64) x)

    1. Initial program 98.3%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.3%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.3%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.3%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.3%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.3%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 1.00005:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 98.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{x}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (hypot 1.0 x) 2.0)
   (* 0.125 (* x x))
   (- 1.0 (sqrt (+ 0.5 (/ 0.5 x))))))
double code(double x) {
	double tmp;
	if (hypot(1.0, x) <= 2.0) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 1.0 - sqrt((0.5 + (0.5 / x)));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (Math.hypot(1.0, x) <= 2.0) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 1.0 - Math.sqrt((0.5 + (0.5 / x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if math.hypot(1.0, x) <= 2.0:
		tmp = 0.125 * (x * x)
	else:
		tmp = 1.0 - math.sqrt((0.5 + (0.5 / x)))
	return tmp
function code(x)
	tmp = 0.0
	if (hypot(1.0, x) <= 2.0)
		tmp = Float64(0.125 * Float64(x * x));
	else
		tmp = Float64(1.0 - sqrt(Float64(0.5 + Float64(0.5 / x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (hypot(1.0, x) <= 2.0)
		tmp = 0.125 * (x * x);
	else
		tmp = 1.0 - sqrt((0.5 + (0.5 / x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 2.0], N[(0.125 * N[(x * x), $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Sqrt[N[(0.5 + N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\
\;\;\;\;0.125 \cdot \left(x \cdot x\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{x}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (hypot.f64 #s(literal 1 binary64) x) < 2

    1. Initial program 52.8%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in52.8%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval52.8%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/52.8%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval52.8%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified52.8%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 52.6%

      \[\leadsto 1 - \color{blue}{\left(1 + -0.125 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative52.6%

        \[\leadsto 1 - \left(1 + \color{blue}{{x}^{2} \cdot -0.125}\right) \]
    7. Simplified52.6%

      \[\leadsto 1 - \color{blue}{\left(1 + {x}^{2} \cdot -0.125\right)} \]
    8. Step-by-step derivation
      1. associate--r+99.3%

        \[\leadsto \color{blue}{\left(1 - 1\right) - {x}^{2} \cdot -0.125} \]
      2. metadata-eval99.3%

        \[\leadsto \color{blue}{0} - {x}^{2} \cdot -0.125 \]
      3. flip--33.8%

        \[\leadsto \color{blue}{\frac{0 \cdot 0 - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125}} \]
      4. metadata-eval33.8%

        \[\leadsto \frac{\color{blue}{0} - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      5. swap-sqr33.8%

        \[\leadsto \frac{0 - \color{blue}{\left({x}^{2} \cdot {x}^{2}\right) \cdot \left(-0.125 \cdot -0.125\right)}}{0 + {x}^{2} \cdot -0.125} \]
      6. pow-prod-up33.6%

        \[\leadsto \frac{0 - \color{blue}{{x}^{\left(2 + 2\right)}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      7. metadata-eval33.6%

        \[\leadsto \frac{0 - {x}^{\color{blue}{4}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      8. metadata-eval33.6%

        \[\leadsto \frac{0 - {x}^{4} \cdot \color{blue}{0.015625}}{0 + {x}^{2} \cdot -0.125} \]
    9. Applied egg-rr33.6%

      \[\leadsto \color{blue}{\frac{0 - {x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
    10. Step-by-step derivation
      1. div-sub33.6%

        \[\leadsto \color{blue}{\frac{0}{0 + {x}^{2} \cdot -0.125} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      2. +-lft-identity33.6%

        \[\leadsto \frac{0}{\color{blue}{{x}^{2} \cdot -0.125}} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      3. div033.6%

        \[\leadsto \color{blue}{0} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      4. neg-sub033.6%

        \[\leadsto \color{blue}{-\frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      5. *-commutative33.6%

        \[\leadsto -\frac{\color{blue}{0.015625 \cdot {x}^{4}}}{0 + {x}^{2} \cdot -0.125} \]
      6. +-lft-identity33.6%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{{x}^{2} \cdot -0.125}} \]
      7. *-commutative33.6%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{-0.125 \cdot {x}^{2}}} \]
      8. times-frac33.7%

        \[\leadsto -\color{blue}{\frac{0.015625}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      9. metadata-eval33.7%

        \[\leadsto -\color{blue}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
      10. distribute-lft-neg-in33.7%

        \[\leadsto \color{blue}{\left(--0.125\right) \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      11. metadata-eval33.7%

        \[\leadsto \color{blue}{0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
    11. Simplified33.7%

      \[\leadsto \color{blue}{0.125 \cdot \frac{{x}^{4}}{{x}^{2}}} \]
    12. Step-by-step derivation
      1. pow-div99.3%

        \[\leadsto 0.125 \cdot \color{blue}{{x}^{\left(4 - 2\right)}} \]
      2. metadata-eval99.3%

        \[\leadsto 0.125 \cdot {x}^{\color{blue}{2}} \]
      3. unpow299.3%

        \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]
    13. Applied egg-rr99.3%

      \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]

    if 2 < (hypot.f64 #s(literal 1 binary64) x)

    1. Initial program 98.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 96.8%

      \[\leadsto 1 - \sqrt{\color{blue}{0.5 + 0.5 \cdot \frac{1}{x}}} \]
    6. Step-by-step derivation
      1. associate-*r/96.8%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{x}}} \]
      2. metadata-eval96.8%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{x}} \]
    7. Simplified96.8%

      \[\leadsto 1 - \sqrt{\color{blue}{0.5 + \frac{0.5}{x}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \sqrt{0.5 + \frac{0.5}{x}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 74.7% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.55:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{1 + \sqrt{0.5}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.55) (* 0.125 (* x x)) (/ 0.5 (+ 1.0 (sqrt 0.5)))))
double code(double x) {
	double tmp;
	if (x <= 1.55) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 0.5 / (1.0 + sqrt(0.5));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.55d0) then
        tmp = 0.125d0 * (x * x)
    else
        tmp = 0.5d0 / (1.0d0 + sqrt(0.5d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.55) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 0.5 / (1.0 + Math.sqrt(0.5));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.55:
		tmp = 0.125 * (x * x)
	else:
		tmp = 0.5 / (1.0 + math.sqrt(0.5))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.55)
		tmp = Float64(0.125 * Float64(x * x));
	else
		tmp = Float64(0.5 / Float64(1.0 + sqrt(0.5)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.55)
		tmp = 0.125 * (x * x);
	else
		tmp = 0.5 / (1.0 + sqrt(0.5));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.55], N[(0.125 * N[(x * x), $MachinePrecision]), $MachinePrecision], N[(0.5 / N[(1.0 + N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.55:\\
\;\;\;\;0.125 \cdot \left(x \cdot x\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5}{1 + \sqrt{0.5}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.55000000000000004

    1. Initial program 68.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in68.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval68.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/68.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval68.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified68.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 36.3%

      \[\leadsto 1 - \color{blue}{\left(1 + -0.125 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative36.3%

        \[\leadsto 1 - \left(1 + \color{blue}{{x}^{2} \cdot -0.125}\right) \]
    7. Simplified36.3%

      \[\leadsto 1 - \color{blue}{\left(1 + {x}^{2} \cdot -0.125\right)} \]
    8. Step-by-step derivation
      1. associate--r+67.1%

        \[\leadsto \color{blue}{\left(1 - 1\right) - {x}^{2} \cdot -0.125} \]
      2. metadata-eval67.1%

        \[\leadsto \color{blue}{0} - {x}^{2} \cdot -0.125 \]
      3. flip--23.5%

        \[\leadsto \color{blue}{\frac{0 \cdot 0 - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125}} \]
      4. metadata-eval23.5%

        \[\leadsto \frac{\color{blue}{0} - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      5. swap-sqr23.5%

        \[\leadsto \frac{0 - \color{blue}{\left({x}^{2} \cdot {x}^{2}\right) \cdot \left(-0.125 \cdot -0.125\right)}}{0 + {x}^{2} \cdot -0.125} \]
      6. pow-prod-up23.4%

        \[\leadsto \frac{0 - \color{blue}{{x}^{\left(2 + 2\right)}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      7. metadata-eval23.4%

        \[\leadsto \frac{0 - {x}^{\color{blue}{4}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      8. metadata-eval23.4%

        \[\leadsto \frac{0 - {x}^{4} \cdot \color{blue}{0.015625}}{0 + {x}^{2} \cdot -0.125} \]
    9. Applied egg-rr23.4%

      \[\leadsto \color{blue}{\frac{0 - {x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
    10. Step-by-step derivation
      1. div-sub23.4%

        \[\leadsto \color{blue}{\frac{0}{0 + {x}^{2} \cdot -0.125} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      2. +-lft-identity23.4%

        \[\leadsto \frac{0}{\color{blue}{{x}^{2} \cdot -0.125}} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      3. div023.4%

        \[\leadsto \color{blue}{0} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      4. neg-sub023.4%

        \[\leadsto \color{blue}{-\frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      5. *-commutative23.4%

        \[\leadsto -\frac{\color{blue}{0.015625 \cdot {x}^{4}}}{0 + {x}^{2} \cdot -0.125} \]
      6. +-lft-identity23.4%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{{x}^{2} \cdot -0.125}} \]
      7. *-commutative23.4%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{-0.125 \cdot {x}^{2}}} \]
      8. times-frac23.4%

        \[\leadsto -\color{blue}{\frac{0.015625}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      9. metadata-eval23.4%

        \[\leadsto -\color{blue}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
      10. distribute-lft-neg-in23.4%

        \[\leadsto \color{blue}{\left(--0.125\right) \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      11. metadata-eval23.4%

        \[\leadsto \color{blue}{0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
    11. Simplified23.4%

      \[\leadsto \color{blue}{0.125 \cdot \frac{{x}^{4}}{{x}^{2}}} \]
    12. Step-by-step derivation
      1. pow-div67.1%

        \[\leadsto 0.125 \cdot \color{blue}{{x}^{\left(4 - 2\right)}} \]
      2. metadata-eval67.1%

        \[\leadsto 0.125 \cdot {x}^{\color{blue}{2}} \]
      3. unpow267.1%

        \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]
    13. Applied egg-rr67.1%

      \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]

    if 1.55000000000000004 < x

    1. Initial program 98.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--98.5%

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
      2. metadata-eval98.5%

        \[\leadsto \frac{\color{blue}{1} - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      3. add-sqr-sqrt100.0%

        \[\leadsto \frac{1 - \color{blue}{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. associate--r+100.0%

        \[\leadsto \frac{\color{blue}{\left(1 - 0.5\right) - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      5. metadata-eval100.0%

        \[\leadsto \frac{\color{blue}{0.5} - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    6. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
    7. Taylor expanded in x around inf 99.8%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{\color{blue}{1 + \left(\sqrt{0.5} + 0.25 \cdot \frac{1}{x \cdot \sqrt{0.5}}\right)}} \]
    8. Step-by-step derivation
      1. associate-+r+99.8%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{\color{blue}{\left(1 + \sqrt{0.5}\right) + 0.25 \cdot \frac{1}{x \cdot \sqrt{0.5}}}} \]
      2. associate-*r/99.8%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{\left(1 + \sqrt{0.5}\right) + \color{blue}{\frac{0.25 \cdot 1}{x \cdot \sqrt{0.5}}}} \]
      3. metadata-eval99.8%

        \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{\left(1 + \sqrt{0.5}\right) + \frac{\color{blue}{0.25}}{x \cdot \sqrt{0.5}}} \]
    9. Simplified99.8%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{\color{blue}{\left(1 + \sqrt{0.5}\right) + \frac{0.25}{x \cdot \sqrt{0.5}}}} \]
    10. Taylor expanded in x around inf 99.2%

      \[\leadsto \color{blue}{\frac{0.5}{1 + \sqrt{0.5}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification75.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.55:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{1 + \sqrt{0.5}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 10: 74.3% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.55:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \sqrt{0.5}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.55) (* 0.125 (* x x)) (- 1.0 (sqrt 0.5))))
double code(double x) {
	double tmp;
	if (x <= 1.55) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 1.0 - sqrt(0.5);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.55d0) then
        tmp = 0.125d0 * (x * x)
    else
        tmp = 1.0d0 - sqrt(0.5d0)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.55) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 1.0 - Math.sqrt(0.5);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.55:
		tmp = 0.125 * (x * x)
	else:
		tmp = 1.0 - math.sqrt(0.5)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.55)
		tmp = Float64(0.125 * Float64(x * x));
	else
		tmp = Float64(1.0 - sqrt(0.5));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.55)
		tmp = 0.125 * (x * x);
	else
		tmp = 1.0 - sqrt(0.5);
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.55], N[(0.125 * N[(x * x), $MachinePrecision]), $MachinePrecision], N[(1.0 - N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.55:\\
\;\;\;\;0.125 \cdot \left(x \cdot x\right)\\

\mathbf{else}:\\
\;\;\;\;1 - \sqrt{0.5}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.55000000000000004

    1. Initial program 68.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in68.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval68.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/68.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval68.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified68.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 36.3%

      \[\leadsto 1 - \color{blue}{\left(1 + -0.125 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative36.3%

        \[\leadsto 1 - \left(1 + \color{blue}{{x}^{2} \cdot -0.125}\right) \]
    7. Simplified36.3%

      \[\leadsto 1 - \color{blue}{\left(1 + {x}^{2} \cdot -0.125\right)} \]
    8. Step-by-step derivation
      1. associate--r+67.1%

        \[\leadsto \color{blue}{\left(1 - 1\right) - {x}^{2} \cdot -0.125} \]
      2. metadata-eval67.1%

        \[\leadsto \color{blue}{0} - {x}^{2} \cdot -0.125 \]
      3. flip--23.5%

        \[\leadsto \color{blue}{\frac{0 \cdot 0 - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125}} \]
      4. metadata-eval23.5%

        \[\leadsto \frac{\color{blue}{0} - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      5. swap-sqr23.5%

        \[\leadsto \frac{0 - \color{blue}{\left({x}^{2} \cdot {x}^{2}\right) \cdot \left(-0.125 \cdot -0.125\right)}}{0 + {x}^{2} \cdot -0.125} \]
      6. pow-prod-up23.4%

        \[\leadsto \frac{0 - \color{blue}{{x}^{\left(2 + 2\right)}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      7. metadata-eval23.4%

        \[\leadsto \frac{0 - {x}^{\color{blue}{4}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      8. metadata-eval23.4%

        \[\leadsto \frac{0 - {x}^{4} \cdot \color{blue}{0.015625}}{0 + {x}^{2} \cdot -0.125} \]
    9. Applied egg-rr23.4%

      \[\leadsto \color{blue}{\frac{0 - {x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
    10. Step-by-step derivation
      1. div-sub23.4%

        \[\leadsto \color{blue}{\frac{0}{0 + {x}^{2} \cdot -0.125} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      2. +-lft-identity23.4%

        \[\leadsto \frac{0}{\color{blue}{{x}^{2} \cdot -0.125}} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      3. div023.4%

        \[\leadsto \color{blue}{0} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      4. neg-sub023.4%

        \[\leadsto \color{blue}{-\frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      5. *-commutative23.4%

        \[\leadsto -\frac{\color{blue}{0.015625 \cdot {x}^{4}}}{0 + {x}^{2} \cdot -0.125} \]
      6. +-lft-identity23.4%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{{x}^{2} \cdot -0.125}} \]
      7. *-commutative23.4%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{-0.125 \cdot {x}^{2}}} \]
      8. times-frac23.4%

        \[\leadsto -\color{blue}{\frac{0.015625}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      9. metadata-eval23.4%

        \[\leadsto -\color{blue}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
      10. distribute-lft-neg-in23.4%

        \[\leadsto \color{blue}{\left(--0.125\right) \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      11. metadata-eval23.4%

        \[\leadsto \color{blue}{0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
    11. Simplified23.4%

      \[\leadsto \color{blue}{0.125 \cdot \frac{{x}^{4}}{{x}^{2}}} \]
    12. Step-by-step derivation
      1. pow-div67.1%

        \[\leadsto 0.125 \cdot \color{blue}{{x}^{\left(4 - 2\right)}} \]
      2. metadata-eval67.1%

        \[\leadsto 0.125 \cdot {x}^{\color{blue}{2}} \]
      3. unpow267.1%

        \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]
    13. Applied egg-rr67.1%

      \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]

    if 1.55000000000000004 < x

    1. Initial program 98.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.6%

      \[\leadsto \color{blue}{1 - \sqrt{0.5}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.55:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;1 - \sqrt{0.5}\\ \end{array} \]
  5. Add Preprocessing

Alternative 11: 56.3% accurate, 21.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.4:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;0.25\\ \end{array} \end{array} \]
(FPCore (x) :precision binary64 (if (<= x 1.4) (* 0.125 (* x x)) 0.25))
double code(double x) {
	double tmp;
	if (x <= 1.4) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 0.25;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.4d0) then
        tmp = 0.125d0 * (x * x)
    else
        tmp = 0.25d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.4) {
		tmp = 0.125 * (x * x);
	} else {
		tmp = 0.25;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.4:
		tmp = 0.125 * (x * x)
	else:
		tmp = 0.25
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.4)
		tmp = Float64(0.125 * Float64(x * x));
	else
		tmp = 0.25;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.4)
		tmp = 0.125 * (x * x);
	else
		tmp = 0.25;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.4], N[(0.125 * N[(x * x), $MachinePrecision]), $MachinePrecision], 0.25]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.4:\\
\;\;\;\;0.125 \cdot \left(x \cdot x\right)\\

\mathbf{else}:\\
\;\;\;\;0.25\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.3999999999999999

    1. Initial program 68.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in68.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval68.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/68.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval68.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified68.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 36.3%

      \[\leadsto 1 - \color{blue}{\left(1 + -0.125 \cdot {x}^{2}\right)} \]
    6. Step-by-step derivation
      1. *-commutative36.3%

        \[\leadsto 1 - \left(1 + \color{blue}{{x}^{2} \cdot -0.125}\right) \]
    7. Simplified36.3%

      \[\leadsto 1 - \color{blue}{\left(1 + {x}^{2} \cdot -0.125\right)} \]
    8. Step-by-step derivation
      1. associate--r+67.1%

        \[\leadsto \color{blue}{\left(1 - 1\right) - {x}^{2} \cdot -0.125} \]
      2. metadata-eval67.1%

        \[\leadsto \color{blue}{0} - {x}^{2} \cdot -0.125 \]
      3. flip--23.5%

        \[\leadsto \color{blue}{\frac{0 \cdot 0 - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125}} \]
      4. metadata-eval23.5%

        \[\leadsto \frac{\color{blue}{0} - \left({x}^{2} \cdot -0.125\right) \cdot \left({x}^{2} \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      5. swap-sqr23.5%

        \[\leadsto \frac{0 - \color{blue}{\left({x}^{2} \cdot {x}^{2}\right) \cdot \left(-0.125 \cdot -0.125\right)}}{0 + {x}^{2} \cdot -0.125} \]
      6. pow-prod-up23.4%

        \[\leadsto \frac{0 - \color{blue}{{x}^{\left(2 + 2\right)}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      7. metadata-eval23.4%

        \[\leadsto \frac{0 - {x}^{\color{blue}{4}} \cdot \left(-0.125 \cdot -0.125\right)}{0 + {x}^{2} \cdot -0.125} \]
      8. metadata-eval23.4%

        \[\leadsto \frac{0 - {x}^{4} \cdot \color{blue}{0.015625}}{0 + {x}^{2} \cdot -0.125} \]
    9. Applied egg-rr23.4%

      \[\leadsto \color{blue}{\frac{0 - {x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
    10. Step-by-step derivation
      1. div-sub23.4%

        \[\leadsto \color{blue}{\frac{0}{0 + {x}^{2} \cdot -0.125} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      2. +-lft-identity23.4%

        \[\leadsto \frac{0}{\color{blue}{{x}^{2} \cdot -0.125}} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      3. div023.4%

        \[\leadsto \color{blue}{0} - \frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125} \]
      4. neg-sub023.4%

        \[\leadsto \color{blue}{-\frac{{x}^{4} \cdot 0.015625}{0 + {x}^{2} \cdot -0.125}} \]
      5. *-commutative23.4%

        \[\leadsto -\frac{\color{blue}{0.015625 \cdot {x}^{4}}}{0 + {x}^{2} \cdot -0.125} \]
      6. +-lft-identity23.4%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{{x}^{2} \cdot -0.125}} \]
      7. *-commutative23.4%

        \[\leadsto -\frac{0.015625 \cdot {x}^{4}}{\color{blue}{-0.125 \cdot {x}^{2}}} \]
      8. times-frac23.4%

        \[\leadsto -\color{blue}{\frac{0.015625}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      9. metadata-eval23.4%

        \[\leadsto -\color{blue}{-0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
      10. distribute-lft-neg-in23.4%

        \[\leadsto \color{blue}{\left(--0.125\right) \cdot \frac{{x}^{4}}{{x}^{2}}} \]
      11. metadata-eval23.4%

        \[\leadsto \color{blue}{0.125} \cdot \frac{{x}^{4}}{{x}^{2}} \]
    11. Simplified23.4%

      \[\leadsto \color{blue}{0.125 \cdot \frac{{x}^{4}}{{x}^{2}}} \]
    12. Step-by-step derivation
      1. pow-div67.1%

        \[\leadsto 0.125 \cdot \color{blue}{{x}^{\left(4 - 2\right)}} \]
      2. metadata-eval67.1%

        \[\leadsto 0.125 \cdot {x}^{\color{blue}{2}} \]
      3. unpow267.1%

        \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]
    13. Applied egg-rr67.1%

      \[\leadsto 0.125 \cdot \color{blue}{\left(x \cdot x\right)} \]

    if 1.3999999999999999 < x

    1. Initial program 98.5%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/98.5%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval98.5%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified98.5%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--98.5%

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
      2. metadata-eval98.5%

        \[\leadsto \frac{\color{blue}{1} - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      3. add-sqr-sqrt100.0%

        \[\leadsto \frac{1 - \color{blue}{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. associate--r+100.0%

        \[\leadsto \frac{\color{blue}{\left(1 - 0.5\right) - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      5. metadata-eval100.0%

        \[\leadsto \frac{\color{blue}{0.5} - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    6. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
    7. Taylor expanded in x around 0 22.7%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{\color{blue}{2}} \]
    8. Taylor expanded in x around inf 22.7%

      \[\leadsto \frac{\color{blue}{0.5}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification56.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.4:\\ \;\;\;\;0.125 \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;0.25\\ \end{array} \]
  5. Add Preprocessing

Alternative 12: 33.0% accurate, 34.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 2.1 \cdot 10^{-77}:\\ \;\;\;\;0\\ \mathbf{else}:\\ \;\;\;\;0.25\\ \end{array} \end{array} \]
(FPCore (x) :precision binary64 (if (<= x 2.1e-77) 0.0 0.25))
double code(double x) {
	double tmp;
	if (x <= 2.1e-77) {
		tmp = 0.0;
	} else {
		tmp = 0.25;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 2.1d-77) then
        tmp = 0.0d0
    else
        tmp = 0.25d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 2.1e-77) {
		tmp = 0.0;
	} else {
		tmp = 0.25;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 2.1e-77:
		tmp = 0.0
	else:
		tmp = 0.25
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 2.1e-77)
		tmp = 0.0;
	else
		tmp = 0.25;
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 2.1e-77)
		tmp = 0.0;
	else
		tmp = 0.25;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 2.1e-77], 0.0, 0.25]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 2.1 \cdot 10^{-77}:\\
\;\;\;\;0\\

\mathbf{else}:\\
\;\;\;\;0.25\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 2.10000000000000015e-77

    1. Initial program 76.2%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in76.2%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval76.2%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/76.2%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval76.2%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified76.2%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 39.0%

      \[\leadsto 1 - \color{blue}{1} \]

    if 2.10000000000000015e-77 < x

    1. Initial program 75.1%

      \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
    2. Step-by-step derivation
      1. distribute-lft-in75.1%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
      2. metadata-eval75.1%

        \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
      3. associate-*r/75.1%

        \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. metadata-eval75.1%

        \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
    3. Simplified75.1%

      \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--75.1%

        \[\leadsto \color{blue}{\frac{1 \cdot 1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
      2. metadata-eval75.1%

        \[\leadsto \frac{\color{blue}{1} - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}} \cdot \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      3. add-sqr-sqrt76.3%

        \[\leadsto \frac{1 - \color{blue}{\left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      4. associate--r+76.3%

        \[\leadsto \frac{\color{blue}{\left(1 - 0.5\right) - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
      5. metadata-eval76.3%

        \[\leadsto \frac{\color{blue}{0.5} - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
    6. Applied egg-rr76.3%

      \[\leadsto \color{blue}{\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}} \]
    7. Taylor expanded in x around 0 18.4%

      \[\leadsto \frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{\color{blue}{2}} \]
    8. Taylor expanded in x around inf 18.8%

      \[\leadsto \frac{\color{blue}{0.5}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification32.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 2.1 \cdot 10^{-77}:\\ \;\;\;\;0\\ \mathbf{else}:\\ \;\;\;\;0.25\\ \end{array} \]
  5. Add Preprocessing

Alternative 13: 28.1% accurate, 210.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (x) :precision binary64 0.0)
double code(double x) {
	return 0.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.0d0
end function
public static double code(double x) {
	return 0.0;
}
def code(x):
	return 0.0
function code(x)
	return 0.0
end
function tmp = code(x)
	tmp = 0.0;
end
code[x_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 75.8%

    \[1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)} \]
  2. Step-by-step derivation
    1. distribute-lft-in75.8%

      \[\leadsto 1 - \sqrt{\color{blue}{0.5 \cdot 1 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}}} \]
    2. metadata-eval75.8%

      \[\leadsto 1 - \sqrt{\color{blue}{0.5} + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, x\right)}} \]
    3. associate-*r/75.8%

      \[\leadsto 1 - \sqrt{0.5 + \color{blue}{\frac{0.5 \cdot 1}{\mathsf{hypot}\left(1, x\right)}}} \]
    4. metadata-eval75.8%

      \[\leadsto 1 - \sqrt{0.5 + \frac{\color{blue}{0.5}}{\mathsf{hypot}\left(1, x\right)}} \]
  3. Simplified75.8%

    \[\leadsto \color{blue}{1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 27.3%

    \[\leadsto 1 - \color{blue}{1} \]
  6. Final simplification27.3%

    \[\leadsto 0 \]
  7. Add Preprocessing

Reproduce

?
herbie shell --seed 2024059 
(FPCore (x)
  :name "Given's Rotation SVD example, simplified"
  :precision binary64
  (- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))