Hyperbolic arcsine

Percentage Accurate: 18.2% → 99.8%
Time: 6.8s
Alternatives: 8
Speedup: 207.0×

Specification

?
\[\begin{array}{l} \\ \log \left(x + \sqrt{x \cdot x + 1}\right) \end{array} \]
(FPCore (x) :precision binary64 (log (+ x (sqrt (+ (* x x) 1.0)))))
double code(double x) {
	return log((x + sqrt(((x * x) + 1.0))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((x + sqrt(((x * x) + 1.0d0))))
end function
public static double code(double x) {
	return Math.log((x + Math.sqrt(((x * x) + 1.0))));
}
def code(x):
	return math.log((x + math.sqrt(((x * x) + 1.0))))
function code(x)
	return log(Float64(x + sqrt(Float64(Float64(x * x) + 1.0))))
end
function tmp = code(x)
	tmp = log((x + sqrt(((x * x) + 1.0))));
end
code[x_] := N[Log[N[(x + N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\log \left(x + \sqrt{x \cdot x + 1}\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 8 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: 18.2% accurate, 1.0× speedup?

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

\\
\log \left(x + \sqrt{x \cdot x + 1}\right)
\end{array}

Alternative 1: 99.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.0075:\\ \;\;\;\;-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;x + \left(-0.16666666666666666 \cdot {x}^{3} + 0.075 \cdot {x}^{5}\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -0.0075)
   (- (log (- (hypot 1.0 x) x)))
   (if (<= x 1.05)
     (+ x (+ (* -0.16666666666666666 (pow x 3.0)) (* 0.075 (pow x 5.0))))
     (log (+ (* x 2.0) (* 0.5 (/ 1.0 x)))))))
double code(double x) {
	double tmp;
	if (x <= -0.0075) {
		tmp = -log((hypot(1.0, x) - x));
	} else if (x <= 1.05) {
		tmp = x + ((-0.16666666666666666 * pow(x, 3.0)) + (0.075 * pow(x, 5.0)));
	} else {
		tmp = log(((x * 2.0) + (0.5 * (1.0 / x))));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= -0.0075) {
		tmp = -Math.log((Math.hypot(1.0, x) - x));
	} else if (x <= 1.05) {
		tmp = x + ((-0.16666666666666666 * Math.pow(x, 3.0)) + (0.075 * Math.pow(x, 5.0)));
	} else {
		tmp = Math.log(((x * 2.0) + (0.5 * (1.0 / x))));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -0.0075:
		tmp = -math.log((math.hypot(1.0, x) - x))
	elif x <= 1.05:
		tmp = x + ((-0.16666666666666666 * math.pow(x, 3.0)) + (0.075 * math.pow(x, 5.0)))
	else:
		tmp = math.log(((x * 2.0) + (0.5 * (1.0 / x))))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -0.0075)
		tmp = Float64(-log(Float64(hypot(1.0, x) - x)));
	elseif (x <= 1.05)
		tmp = Float64(x + Float64(Float64(-0.16666666666666666 * (x ^ 3.0)) + Float64(0.075 * (x ^ 5.0))));
	else
		tmp = log(Float64(Float64(x * 2.0) + Float64(0.5 * Float64(1.0 / x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -0.0075)
		tmp = -log((hypot(1.0, x) - x));
	elseif (x <= 1.05)
		tmp = x + ((-0.16666666666666666 * (x ^ 3.0)) + (0.075 * (x ^ 5.0)));
	else
		tmp = log(((x * 2.0) + (0.5 * (1.0 / x))));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -0.0075], (-N[Log[N[(N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision] - x), $MachinePrecision]], $MachinePrecision]), If[LessEqual[x, 1.05], N[(x + N[(N[(-0.16666666666666666 * N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision] + N[(0.075 * N[Power[x, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[(x * 2.0), $MachinePrecision] + N[(0.5 * N[(1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.0075:\\
\;\;\;\;-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)\\

\mathbf{elif}\;x \leq 1.05:\\
\;\;\;\;x + \left(-0.16666666666666666 \cdot {x}^{3} + 0.075 \cdot {x}^{5}\right)\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -0.0074999999999999997

    1. Initial program 3.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def4.5%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified4.5%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutative4.5%

        \[\leadsto \log \color{blue}{\left(\mathsf{hypot}\left(1, x\right) + x\right)} \]
      2. flip-+2.7%

        \[\leadsto \log \color{blue}{\left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\mathsf{hypot}\left(1, x\right) - x}\right)} \]
      3. clear-num2.7%

        \[\leadsto \log \color{blue}{\left(\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}\right)} \]
      4. log-div2.7%

        \[\leadsto \color{blue}{\log 1 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}\right)} \]
      5. metadata-eval2.7%

        \[\leadsto \color{blue}{0} - \log \left(\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}\right) \]
      6. remove-double-div2.7%

        \[\leadsto 0 - \log \color{blue}{\left(\frac{1}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right)} \]
      7. metadata-eval2.7%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{1 + 0}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      8. +-inverses2.7%

        \[\leadsto 0 - \log \left(\frac{1 + \color{blue}{\left(x \cdot x - x \cdot x\right)}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      9. associate--l+1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\left(1 + x \cdot x\right) - x \cdot x}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      10. metadata-eval1.6%

        \[\leadsto 0 - \log \left(\frac{\left(\color{blue}{1 \cdot 1} + x \cdot x\right) - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      11. rem-square-sqrt1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\sqrt{1 \cdot 1 + x \cdot x} \cdot \sqrt{1 \cdot 1 + x \cdot x}} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      12. hypot-udef1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\mathsf{hypot}\left(1, x\right)} \cdot \sqrt{1 \cdot 1 + x \cdot x} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      13. hypot-udef1.6%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \color{blue}{\mathsf{hypot}\left(1, x\right)} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      14. clear-num1.6%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\color{blue}{\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\mathsf{hypot}\left(1, x\right) - x}}}\right) \]
      15. flip-+1.4%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\color{blue}{\mathsf{hypot}\left(1, x\right) + x}}\right) \]
      16. flip--100.0%

        \[\leadsto 0 - \log \color{blue}{\left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{0 - \log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    6. Step-by-step derivation
      1. sub0-neg100.0%

        \[\leadsto \color{blue}{-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]

    if -0.0074999999999999997 < x < 1.05000000000000004

    1. Initial program 7.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def7.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified7.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{x + \left(-0.16666666666666666 \cdot {x}^{3} + 0.075 \cdot {x}^{5}\right)} \]

    if 1.05000000000000004 < x

    1. Initial program 48.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def100.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around inf 100.0%

      \[\leadsto \log \color{blue}{\left(2 \cdot x + 0.5 \cdot \frac{1}{x}\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.0075:\\ \;\;\;\;-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;x + \left(-0.16666666666666666 \cdot {x}^{3} + 0.075 \cdot {x}^{5}\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\ \end{array} \]

Alternative 2: 99.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.00105:\\ \;\;\;\;-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -0.00105)
   (- (log (- (hypot 1.0 x) x)))
   (if (<= x 0.96)
     (+ x (* -0.16666666666666666 (pow x 3.0)))
     (log (+ (* x 2.0) (* 0.5 (/ 1.0 x)))))))
double code(double x) {
	double tmp;
	if (x <= -0.00105) {
		tmp = -log((hypot(1.0, x) - x));
	} else if (x <= 0.96) {
		tmp = x + (-0.16666666666666666 * pow(x, 3.0));
	} else {
		tmp = log(((x * 2.0) + (0.5 * (1.0 / x))));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= -0.00105) {
		tmp = -Math.log((Math.hypot(1.0, x) - x));
	} else if (x <= 0.96) {
		tmp = x + (-0.16666666666666666 * Math.pow(x, 3.0));
	} else {
		tmp = Math.log(((x * 2.0) + (0.5 * (1.0 / x))));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -0.00105:
		tmp = -math.log((math.hypot(1.0, x) - x))
	elif x <= 0.96:
		tmp = x + (-0.16666666666666666 * math.pow(x, 3.0))
	else:
		tmp = math.log(((x * 2.0) + (0.5 * (1.0 / x))))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -0.00105)
		tmp = Float64(-log(Float64(hypot(1.0, x) - x)));
	elseif (x <= 0.96)
		tmp = Float64(x + Float64(-0.16666666666666666 * (x ^ 3.0)));
	else
		tmp = log(Float64(Float64(x * 2.0) + Float64(0.5 * Float64(1.0 / x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -0.00105)
		tmp = -log((hypot(1.0, x) - x));
	elseif (x <= 0.96)
		tmp = x + (-0.16666666666666666 * (x ^ 3.0));
	else
		tmp = log(((x * 2.0) + (0.5 * (1.0 / x))));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -0.00105], (-N[Log[N[(N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision] - x), $MachinePrecision]], $MachinePrecision]), If[LessEqual[x, 0.96], N[(x + N[(-0.16666666666666666 * N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[(x * 2.0), $MachinePrecision] + N[(0.5 * N[(1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.00105:\\
\;\;\;\;-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)\\

\mathbf{elif}\;x \leq 0.96:\\
\;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -0.00104999999999999994

    1. Initial program 4.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg4.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative4.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg4.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def5.8%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified5.8%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutative5.8%

        \[\leadsto \log \color{blue}{\left(\mathsf{hypot}\left(1, x\right) + x\right)} \]
      2. flip-+4.0%

        \[\leadsto \log \color{blue}{\left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\mathsf{hypot}\left(1, x\right) - x}\right)} \]
      3. clear-num4.0%

        \[\leadsto \log \color{blue}{\left(\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}\right)} \]
      4. log-div3.9%

        \[\leadsto \color{blue}{\log 1 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}\right)} \]
      5. metadata-eval3.9%

        \[\leadsto \color{blue}{0} - \log \left(\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}\right) \]
      6. remove-double-div3.9%

        \[\leadsto 0 - \log \color{blue}{\left(\frac{1}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right)} \]
      7. metadata-eval3.9%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{1 + 0}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      8. +-inverses3.9%

        \[\leadsto 0 - \log \left(\frac{1 + \color{blue}{\left(x \cdot x - x \cdot x\right)}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      9. associate--l+2.9%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\left(1 + x \cdot x\right) - x \cdot x}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      10. metadata-eval2.9%

        \[\leadsto 0 - \log \left(\frac{\left(\color{blue}{1 \cdot 1} + x \cdot x\right) - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      11. rem-square-sqrt2.9%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\sqrt{1 \cdot 1 + x \cdot x} \cdot \sqrt{1 \cdot 1 + x \cdot x}} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      12. hypot-udef2.9%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\mathsf{hypot}\left(1, x\right)} \cdot \sqrt{1 \cdot 1 + x \cdot x} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      13. hypot-udef2.9%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \color{blue}{\mathsf{hypot}\left(1, x\right)} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      14. clear-num2.9%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\color{blue}{\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\mathsf{hypot}\left(1, x\right) - x}}}\right) \]
      15. flip-+2.8%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\color{blue}{\mathsf{hypot}\left(1, x\right) + x}}\right) \]
      16. flip--99.9%

        \[\leadsto 0 - \log \color{blue}{\left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    5. Applied egg-rr99.9%

      \[\leadsto \color{blue}{0 - \log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    6. Step-by-step derivation
      1. sub0-neg99.9%

        \[\leadsto \color{blue}{-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    7. Simplified99.9%

      \[\leadsto \color{blue}{-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]

    if -0.00104999999999999994 < x < 0.95999999999999996

    1. Initial program 6.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg6.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative6.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg6.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def6.3%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified6.3%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{x + -0.16666666666666666 \cdot {x}^{3}} \]

    if 0.95999999999999996 < x

    1. Initial program 48.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def100.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around inf 100.0%

      \[\leadsto \log \color{blue}{\left(2 \cdot x + 0.5 \cdot \frac{1}{x}\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.00105:\\ \;\;\;\;-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\ \end{array} \]

Alternative 3: 99.5% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.96:\\ \;\;\;\;-\log \left(x \cdot -2 - \frac{0.5}{x}\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -0.96)
   (- (log (- (* x -2.0) (/ 0.5 x))))
   (if (<= x 0.96)
     (+ x (* -0.16666666666666666 (pow x 3.0)))
     (log (+ (* x 2.0) (* 0.5 (/ 1.0 x)))))))
double code(double x) {
	double tmp;
	if (x <= -0.96) {
		tmp = -log(((x * -2.0) - (0.5 / x)));
	} else if (x <= 0.96) {
		tmp = x + (-0.16666666666666666 * pow(x, 3.0));
	} else {
		tmp = log(((x * 2.0) + (0.5 * (1.0 / x))));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-0.96d0)) then
        tmp = -log(((x * (-2.0d0)) - (0.5d0 / x)))
    else if (x <= 0.96d0) then
        tmp = x + ((-0.16666666666666666d0) * (x ** 3.0d0))
    else
        tmp = log(((x * 2.0d0) + (0.5d0 * (1.0d0 / x))))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -0.96) {
		tmp = -Math.log(((x * -2.0) - (0.5 / x)));
	} else if (x <= 0.96) {
		tmp = x + (-0.16666666666666666 * Math.pow(x, 3.0));
	} else {
		tmp = Math.log(((x * 2.0) + (0.5 * (1.0 / x))));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -0.96:
		tmp = -math.log(((x * -2.0) - (0.5 / x)))
	elif x <= 0.96:
		tmp = x + (-0.16666666666666666 * math.pow(x, 3.0))
	else:
		tmp = math.log(((x * 2.0) + (0.5 * (1.0 / x))))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -0.96)
		tmp = Float64(-log(Float64(Float64(x * -2.0) - Float64(0.5 / x))));
	elseif (x <= 0.96)
		tmp = Float64(x + Float64(-0.16666666666666666 * (x ^ 3.0)));
	else
		tmp = log(Float64(Float64(x * 2.0) + Float64(0.5 * Float64(1.0 / x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -0.96)
		tmp = -log(((x * -2.0) - (0.5 / x)));
	elseif (x <= 0.96)
		tmp = x + (-0.16666666666666666 * (x ^ 3.0));
	else
		tmp = log(((x * 2.0) + (0.5 * (1.0 / x))));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -0.96], (-N[Log[N[(N[(x * -2.0), $MachinePrecision] - N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), If[LessEqual[x, 0.96], N[(x + N[(-0.16666666666666666 * N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[(x * 2.0), $MachinePrecision] + N[(0.5 * N[(1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.96:\\
\;\;\;\;-\log \left(x \cdot -2 - \frac{0.5}{x}\right)\\

\mathbf{elif}\;x \leq 0.96:\\
\;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -0.95999999999999996

    1. Initial program 3.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def4.5%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified4.5%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutative4.5%

        \[\leadsto \log \color{blue}{\left(\mathsf{hypot}\left(1, x\right) + x\right)} \]
      2. flip-+2.7%

        \[\leadsto \log \color{blue}{\left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\mathsf{hypot}\left(1, x\right) - x}\right)} \]
      3. clear-num2.7%

        \[\leadsto \log \color{blue}{\left(\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}\right)} \]
      4. log-div2.7%

        \[\leadsto \color{blue}{\log 1 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}\right)} \]
      5. metadata-eval2.7%

        \[\leadsto \color{blue}{0} - \log \left(\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}\right) \]
      6. remove-double-div2.7%

        \[\leadsto 0 - \log \color{blue}{\left(\frac{1}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right)} \]
      7. metadata-eval2.7%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{1 + 0}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      8. +-inverses2.7%

        \[\leadsto 0 - \log \left(\frac{1 + \color{blue}{\left(x \cdot x - x \cdot x\right)}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      9. associate--l+1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\left(1 + x \cdot x\right) - x \cdot x}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      10. metadata-eval1.6%

        \[\leadsto 0 - \log \left(\frac{\left(\color{blue}{1 \cdot 1} + x \cdot x\right) - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      11. rem-square-sqrt1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\sqrt{1 \cdot 1 + x \cdot x} \cdot \sqrt{1 \cdot 1 + x \cdot x}} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      12. hypot-udef1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\mathsf{hypot}\left(1, x\right)} \cdot \sqrt{1 \cdot 1 + x \cdot x} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      13. hypot-udef1.6%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \color{blue}{\mathsf{hypot}\left(1, x\right)} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      14. clear-num1.6%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\color{blue}{\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\mathsf{hypot}\left(1, x\right) - x}}}\right) \]
      15. flip-+1.4%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\color{blue}{\mathsf{hypot}\left(1, x\right) + x}}\right) \]
      16. flip--100.0%

        \[\leadsto 0 - \log \color{blue}{\left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{0 - \log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    6. Step-by-step derivation
      1. sub0-neg100.0%

        \[\leadsto \color{blue}{-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    8. Taylor expanded in x around -inf 99.5%

      \[\leadsto -\log \color{blue}{\left(-2 \cdot x - 0.5 \cdot \frac{1}{x}\right)} \]
    9. Step-by-step derivation
      1. *-commutative99.5%

        \[\leadsto -\log \left(\color{blue}{x \cdot -2} - 0.5 \cdot \frac{1}{x}\right) \]
      2. associate-*r/99.5%

        \[\leadsto -\log \left(x \cdot -2 - \color{blue}{\frac{0.5 \cdot 1}{x}}\right) \]
      3. metadata-eval99.5%

        \[\leadsto -\log \left(x \cdot -2 - \frac{\color{blue}{0.5}}{x}\right) \]
    10. Simplified99.5%

      \[\leadsto -\log \color{blue}{\left(x \cdot -2 - \frac{0.5}{x}\right)} \]

    if -0.95999999999999996 < x < 0.95999999999999996

    1. Initial program 7.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def7.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified7.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around 0 99.9%

      \[\leadsto \color{blue}{x + -0.16666666666666666 \cdot {x}^{3}} \]

    if 0.95999999999999996 < x

    1. Initial program 48.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def100.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around inf 100.0%

      \[\leadsto \log \color{blue}{\left(2 \cdot x + 0.5 \cdot \frac{1}{x}\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.96:\\ \;\;\;\;-\log \left(x \cdot -2 - \frac{0.5}{x}\right)\\ \mathbf{elif}\;x \leq 0.96:\\ \;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2 + 0.5 \cdot \frac{1}{x}\right)\\ \end{array} \]

Alternative 4: 99.3% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.25:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.25)
   (log (/ -0.5 x))
   (if (<= x 1.3) (+ x (* -0.16666666666666666 (pow x 3.0))) (log (* x 2.0)))))
double code(double x) {
	double tmp;
	if (x <= -1.25) {
		tmp = log((-0.5 / x));
	} else if (x <= 1.3) {
		tmp = x + (-0.16666666666666666 * pow(x, 3.0));
	} else {
		tmp = log((x * 2.0));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.25d0)) then
        tmp = log(((-0.5d0) / x))
    else if (x <= 1.3d0) then
        tmp = x + ((-0.16666666666666666d0) * (x ** 3.0d0))
    else
        tmp = log((x * 2.0d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.25) {
		tmp = Math.log((-0.5 / x));
	} else if (x <= 1.3) {
		tmp = x + (-0.16666666666666666 * Math.pow(x, 3.0));
	} else {
		tmp = Math.log((x * 2.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.25:
		tmp = math.log((-0.5 / x))
	elif x <= 1.3:
		tmp = x + (-0.16666666666666666 * math.pow(x, 3.0))
	else:
		tmp = math.log((x * 2.0))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.25)
		tmp = log(Float64(-0.5 / x));
	elseif (x <= 1.3)
		tmp = Float64(x + Float64(-0.16666666666666666 * (x ^ 3.0)));
	else
		tmp = log(Float64(x * 2.0));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.25)
		tmp = log((-0.5 / x));
	elseif (x <= 1.3)
		tmp = x + (-0.16666666666666666 * (x ^ 3.0));
	else
		tmp = log((x * 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.25], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.3], N[(x + N[(-0.16666666666666666 * N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Log[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.25:\\
\;\;\;\;\log \left(\frac{-0.5}{x}\right)\\

\mathbf{elif}\;x \leq 1.3:\\
\;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.25

    1. Initial program 3.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def4.5%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified4.5%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around -inf 99.1%

      \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]

    if -1.25 < x < 1.30000000000000004

    1. Initial program 7.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def7.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified7.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around 0 99.9%

      \[\leadsto \color{blue}{x + -0.16666666666666666 \cdot {x}^{3}} \]

    if 1.30000000000000004 < x

    1. Initial program 48.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def100.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around inf 100.0%

      \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
    5. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
    6. Simplified100.0%

      \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.25:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \]

Alternative 5: 99.4% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.96:\\ \;\;\;\;-\log \left(x \cdot -2 - \frac{0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -0.96)
   (- (log (- (* x -2.0) (/ 0.5 x))))
   (if (<= x 1.3) (+ x (* -0.16666666666666666 (pow x 3.0))) (log (* x 2.0)))))
double code(double x) {
	double tmp;
	if (x <= -0.96) {
		tmp = -log(((x * -2.0) - (0.5 / x)));
	} else if (x <= 1.3) {
		tmp = x + (-0.16666666666666666 * pow(x, 3.0));
	} else {
		tmp = log((x * 2.0));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-0.96d0)) then
        tmp = -log(((x * (-2.0d0)) - (0.5d0 / x)))
    else if (x <= 1.3d0) then
        tmp = x + ((-0.16666666666666666d0) * (x ** 3.0d0))
    else
        tmp = log((x * 2.0d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -0.96) {
		tmp = -Math.log(((x * -2.0) - (0.5 / x)));
	} else if (x <= 1.3) {
		tmp = x + (-0.16666666666666666 * Math.pow(x, 3.0));
	} else {
		tmp = Math.log((x * 2.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -0.96:
		tmp = -math.log(((x * -2.0) - (0.5 / x)))
	elif x <= 1.3:
		tmp = x + (-0.16666666666666666 * math.pow(x, 3.0))
	else:
		tmp = math.log((x * 2.0))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -0.96)
		tmp = Float64(-log(Float64(Float64(x * -2.0) - Float64(0.5 / x))));
	elseif (x <= 1.3)
		tmp = Float64(x + Float64(-0.16666666666666666 * (x ^ 3.0)));
	else
		tmp = log(Float64(x * 2.0));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -0.96)
		tmp = -log(((x * -2.0) - (0.5 / x)));
	elseif (x <= 1.3)
		tmp = x + (-0.16666666666666666 * (x ^ 3.0));
	else
		tmp = log((x * 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -0.96], (-N[Log[N[(N[(x * -2.0), $MachinePrecision] - N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), If[LessEqual[x, 1.3], N[(x + N[(-0.16666666666666666 * N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Log[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -0.96:\\
\;\;\;\;-\log \left(x \cdot -2 - \frac{0.5}{x}\right)\\

\mathbf{elif}\;x \leq 1.3:\\
\;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -0.95999999999999996

    1. Initial program 3.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def4.5%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified4.5%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutative4.5%

        \[\leadsto \log \color{blue}{\left(\mathsf{hypot}\left(1, x\right) + x\right)} \]
      2. flip-+2.7%

        \[\leadsto \log \color{blue}{\left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\mathsf{hypot}\left(1, x\right) - x}\right)} \]
      3. clear-num2.7%

        \[\leadsto \log \color{blue}{\left(\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}\right)} \]
      4. log-div2.7%

        \[\leadsto \color{blue}{\log 1 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}\right)} \]
      5. metadata-eval2.7%

        \[\leadsto \color{blue}{0} - \log \left(\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}\right) \]
      6. remove-double-div2.7%

        \[\leadsto 0 - \log \color{blue}{\left(\frac{1}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right)} \]
      7. metadata-eval2.7%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{1 + 0}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      8. +-inverses2.7%

        \[\leadsto 0 - \log \left(\frac{1 + \color{blue}{\left(x \cdot x - x \cdot x\right)}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      9. associate--l+1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\left(1 + x \cdot x\right) - x \cdot x}}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      10. metadata-eval1.6%

        \[\leadsto 0 - \log \left(\frac{\left(\color{blue}{1 \cdot 1} + x \cdot x\right) - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      11. rem-square-sqrt1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\sqrt{1 \cdot 1 + x \cdot x} \cdot \sqrt{1 \cdot 1 + x \cdot x}} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      12. hypot-udef1.6%

        \[\leadsto 0 - \log \left(\frac{\color{blue}{\mathsf{hypot}\left(1, x\right)} \cdot \sqrt{1 \cdot 1 + x \cdot x} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      13. hypot-udef1.6%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \color{blue}{\mathsf{hypot}\left(1, x\right)} - x \cdot x}{\frac{1}{\frac{\mathsf{hypot}\left(1, x\right) - x}{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}}}\right) \]
      14. clear-num1.6%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\color{blue}{\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\mathsf{hypot}\left(1, x\right) - x}}}\right) \]
      15. flip-+1.4%

        \[\leadsto 0 - \log \left(\frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right) - x \cdot x}{\color{blue}{\mathsf{hypot}\left(1, x\right) + x}}\right) \]
      16. flip--100.0%

        \[\leadsto 0 - \log \color{blue}{\left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{0 - \log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    6. Step-by-step derivation
      1. sub0-neg100.0%

        \[\leadsto \color{blue}{-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{-\log \left(\mathsf{hypot}\left(1, x\right) - x\right)} \]
    8. Taylor expanded in x around -inf 99.5%

      \[\leadsto -\log \color{blue}{\left(-2 \cdot x - 0.5 \cdot \frac{1}{x}\right)} \]
    9. Step-by-step derivation
      1. *-commutative99.5%

        \[\leadsto -\log \left(\color{blue}{x \cdot -2} - 0.5 \cdot \frac{1}{x}\right) \]
      2. associate-*r/99.5%

        \[\leadsto -\log \left(x \cdot -2 - \color{blue}{\frac{0.5 \cdot 1}{x}}\right) \]
      3. metadata-eval99.5%

        \[\leadsto -\log \left(x \cdot -2 - \frac{\color{blue}{0.5}}{x}\right) \]
    10. Simplified99.5%

      \[\leadsto -\log \color{blue}{\left(x \cdot -2 - \frac{0.5}{x}\right)} \]

    if -0.95999999999999996 < x < 1.30000000000000004

    1. Initial program 7.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def7.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified7.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around 0 99.9%

      \[\leadsto \color{blue}{x + -0.16666666666666666 \cdot {x}^{3}} \]

    if 1.30000000000000004 < x

    1. Initial program 48.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def100.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around inf 100.0%

      \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
    5. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
    6. Simplified100.0%

      \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -0.96:\\ \;\;\;\;-\log \left(x \cdot -2 - \frac{0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;x + -0.16666666666666666 \cdot {x}^{3}\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \]

Alternative 6: 99.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.25:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.25) (log (/ -0.5 x)) (if (<= x 1.25) x (log (* x 2.0)))))
double code(double x) {
	double tmp;
	if (x <= -1.25) {
		tmp = log((-0.5 / x));
	} else if (x <= 1.25) {
		tmp = x;
	} else {
		tmp = log((x * 2.0));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.25d0)) then
        tmp = log(((-0.5d0) / x))
    else if (x <= 1.25d0) then
        tmp = x
    else
        tmp = log((x * 2.0d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.25) {
		tmp = Math.log((-0.5 / x));
	} else if (x <= 1.25) {
		tmp = x;
	} else {
		tmp = Math.log((x * 2.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.25:
		tmp = math.log((-0.5 / x))
	elif x <= 1.25:
		tmp = x
	else:
		tmp = math.log((x * 2.0))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.25)
		tmp = log(Float64(-0.5 / x));
	elseif (x <= 1.25)
		tmp = x;
	else
		tmp = log(Float64(x * 2.0));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.25)
		tmp = log((-0.5 / x));
	elseif (x <= 1.25)
		tmp = x;
	else
		tmp = log((x * 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.25], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.25], x, N[Log[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.25:\\
\;\;\;\;\log \left(\frac{-0.5}{x}\right)\\

\mathbf{elif}\;x \leq 1.25:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.25

    1. Initial program 3.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative3.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg3.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def4.5%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified4.5%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around -inf 99.1%

      \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]

    if -1.25 < x < 1.25

    1. Initial program 7.0%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative7.0%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg7.0%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def7.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified7.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around 0 99.6%

      \[\leadsto \color{blue}{x} \]

    if 1.25 < x

    1. Initial program 48.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def100.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around inf 100.0%

      \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
    5. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
    6. Simplified100.0%

      \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.25:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \]

Alternative 7: 75.4% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \end{array} \]
(FPCore (x) :precision binary64 (if (<= x 1.25) x (log (* x 2.0))))
double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = x;
	} else {
		tmp = log((x * 2.0));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.25d0) then
        tmp = x
    else
        tmp = log((x * 2.0d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = x;
	} else {
		tmp = Math.log((x * 2.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.25:
		tmp = x
	else:
		tmp = math.log((x * 2.0))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.25)
		tmp = x;
	else
		tmp = log(Float64(x * 2.0));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.25)
		tmp = x;
	else
		tmp = log((x * 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.25], x, N[Log[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.25:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;\log \left(x \cdot 2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.25

    1. Initial program 5.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg5.6%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative5.6%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg5.6%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def6.2%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified6.2%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around 0 66.5%

      \[\leadsto \color{blue}{x} \]

    if 1.25 < x

    1. Initial program 48.3%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Step-by-step derivation
      1. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
      2. +-commutative48.3%

        \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
      3. sqr-neg48.3%

        \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
      4. hypot-1-def100.0%

        \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
    4. Taylor expanded in x around inf 100.0%

      \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
    5. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
    6. Simplified100.0%

      \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification76.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \]

Alternative 8: 52.2% accurate, 207.0× speedup?

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

\\
x
\end{array}
Derivation
  1. Initial program 17.7%

    \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
  2. Step-by-step derivation
    1. sqr-neg17.7%

      \[\leadsto \log \left(x + \sqrt{\color{blue}{\left(-x\right) \cdot \left(-x\right)} + 1}\right) \]
    2. +-commutative17.7%

      \[\leadsto \log \left(x + \sqrt{\color{blue}{1 + \left(-x\right) \cdot \left(-x\right)}}\right) \]
    3. sqr-neg17.7%

      \[\leadsto \log \left(x + \sqrt{1 + \color{blue}{x \cdot x}}\right) \]
    4. hypot-1-def32.9%

      \[\leadsto \log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right) \]
  3. Simplified32.9%

    \[\leadsto \color{blue}{\log \left(x + \mathsf{hypot}\left(1, x\right)\right)} \]
  4. Taylor expanded in x around 0 49.0%

    \[\leadsto \color{blue}{x} \]
  5. Final simplification49.0%

    \[\leadsto x \]

Developer target: 30.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{x \cdot x + 1}\\ \mathbf{if}\;x < 0:\\ \;\;\;\;\log \left(\frac{-1}{x - t_0}\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + t_0\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (sqrt (+ (* x x) 1.0))))
   (if (< x 0.0) (log (/ -1.0 (- x t_0))) (log (+ x t_0)))))
double code(double x) {
	double t_0 = sqrt(((x * x) + 1.0));
	double tmp;
	if (x < 0.0) {
		tmp = log((-1.0 / (x - t_0)));
	} else {
		tmp = log((x + t_0));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = sqrt(((x * x) + 1.0d0))
    if (x < 0.0d0) then
        tmp = log(((-1.0d0) / (x - t_0)))
    else
        tmp = log((x + t_0))
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = Math.sqrt(((x * x) + 1.0));
	double tmp;
	if (x < 0.0) {
		tmp = Math.log((-1.0 / (x - t_0)));
	} else {
		tmp = Math.log((x + t_0));
	}
	return tmp;
}
def code(x):
	t_0 = math.sqrt(((x * x) + 1.0))
	tmp = 0
	if x < 0.0:
		tmp = math.log((-1.0 / (x - t_0)))
	else:
		tmp = math.log((x + t_0))
	return tmp
function code(x)
	t_0 = sqrt(Float64(Float64(x * x) + 1.0))
	tmp = 0.0
	if (x < 0.0)
		tmp = log(Float64(-1.0 / Float64(x - t_0)));
	else
		tmp = log(Float64(x + t_0));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = sqrt(((x * x) + 1.0));
	tmp = 0.0;
	if (x < 0.0)
		tmp = log((-1.0 / (x - t_0)));
	else
		tmp = log((x + t_0));
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]}, If[Less[x, 0.0], N[Log[N[(-1.0 / N[(x - t$95$0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Log[N[(x + t$95$0), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt{x \cdot x + 1}\\
\mathbf{if}\;x < 0:\\
\;\;\;\;\log \left(\frac{-1}{x - t_0}\right)\\

\mathbf{else}:\\
\;\;\;\;\log \left(x + t_0\right)\\


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2023297 
(FPCore (x)
  :name "Hyperbolic arcsine"
  :precision binary64

  :herbie-target
  (if (< x 0.0) (log (/ -1.0 (- x (sqrt (+ (* x x) 1.0))))) (log (+ x (sqrt (+ (* x x) 1.0)))))

  (log (+ x (sqrt (+ (* x x) 1.0)))))