Hyperbolic arcsine

Percentage Accurate: 17.5% → 99.5%
Time: 10.2s
Alternatives: 5
Speedup: 122.0×

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 5 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: 17.5% 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: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;0 - \log \left(\mathsf{fma}\left(-2, x, \frac{-0.5}{x}\right)\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.05)
   (- 0.0 (log (fma -2.0 x (/ -0.5 x))))
   (if (<= x 1.32)
     (* x (fma (* x x) (fma x (* x 0.075) -0.16666666666666666) 1.0))
     (log (+ x x)))))
double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = 0.0 - log(fma(-2.0, x, (-0.5 / x)));
	} else if (x <= 1.32) {
		tmp = x * fma((x * x), fma(x, (x * 0.075), -0.16666666666666666), 1.0);
	} else {
		tmp = log((x + x));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.05)
		tmp = Float64(0.0 - log(fma(-2.0, x, Float64(-0.5 / x))));
	elseif (x <= 1.32)
		tmp = Float64(x * fma(Float64(x * x), fma(x, Float64(x * 0.075), -0.16666666666666666), 1.0));
	else
		tmp = log(Float64(x + x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.05], N[(0.0 - N[Log[N[(-2.0 * x + N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.32], N[(x * N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;0 - \log \left(\mathsf{fma}\left(-2, x, \frac{-0.5}{x}\right)\right)\\

\mathbf{elif}\;x \leq 1.32:\\
\;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.05000000000000004

    1. Initial program 3.8%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \log \color{blue}{\left(\sqrt{x \cdot x + 1} + x\right)} \]
      2. +-lowering-+.f64N/A

        \[\leadsto \log \color{blue}{\left(\sqrt{x \cdot x + 1} + x\right)} \]
      3. sqrt-lowering-sqrt.f64N/A

        \[\leadsto \log \left(\color{blue}{\sqrt{x \cdot x + 1}} + x\right) \]
      4. accelerator-lowering-fma.f643.8

        \[\leadsto \log \left(\sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}} + x\right) \]
    4. Applied egg-rr3.8%

      \[\leadsto \log \color{blue}{\left(\sqrt{\mathsf{fma}\left(x, x, 1\right)} + x\right)} \]
    5. Step-by-step derivation
      1. flip-+N/A

        \[\leadsto \log \color{blue}{\left(\frac{\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot x}{\sqrt{x \cdot x + 1} - x}\right)} \]
      2. flip3--N/A

        \[\leadsto \log \left(\frac{\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot x}{\color{blue}{\frac{{\left(\sqrt{x \cdot x + 1}\right)}^{3} - {x}^{3}}{\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + \left(x \cdot x + \sqrt{x \cdot x + 1} \cdot x\right)}}}\right) \]
      3. associate-/r/N/A

        \[\leadsto \log \color{blue}{\left(\frac{\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot x}{{\left(\sqrt{x \cdot x + 1}\right)}^{3} - {x}^{3}} \cdot \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + \left(x \cdot x + \sqrt{x \cdot x + 1} \cdot x\right)\right)\right)} \]
      4. rem-square-sqrtN/A

        \[\leadsto \log \left(\frac{\color{blue}{\left(x \cdot x + 1\right)} - x \cdot x}{{\left(\sqrt{x \cdot x + 1}\right)}^{3} - {x}^{3}} \cdot \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + \left(x \cdot x + \sqrt{x \cdot x + 1} \cdot x\right)\right)\right) \]
      5. associate-+r-N/A

        \[\leadsto \log \left(\frac{\color{blue}{x \cdot x + \left(1 - x \cdot x\right)}}{{\left(\sqrt{x \cdot x + 1}\right)}^{3} - {x}^{3}} \cdot \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + \left(x \cdot x + \sqrt{x \cdot x + 1} \cdot x\right)\right)\right) \]
    6. Applied egg-rr50.1%

      \[\leadsto \color{blue}{-\log \left(\sqrt{\mathsf{fma}\left(x, x, 1\right)} - x\right)} \]
    7. Taylor expanded in x around -inf

      \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(-1 \cdot \left(x \cdot \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)}\right) \]
    8. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(\mathsf{neg}\left(x \cdot \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)}\right) \]
      2. distribute-rgt-inN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{neg}\left(\color{blue}{\left(2 \cdot x + \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)}\right)\right)\right) \]
      3. distribute-neg-inN/A

        \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(\left(\mathsf{neg}\left(2 \cdot x\right)\right) + \left(\mathsf{neg}\left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right)}\right) \]
      4. distribute-lft-neg-inN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\color{blue}{\left(\mathsf{neg}\left(2\right)\right) \cdot x} + \left(\mathsf{neg}\left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right)\right) \]
      5. metadata-evalN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\color{blue}{-2} \cdot x + \left(\mathsf{neg}\left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right)\right) \]
      6. accelerator-lowering-fma.f64N/A

        \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(\mathsf{fma}\left(-2, x, \mathsf{neg}\left(\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right)}\right) \]
      7. associate-*l*N/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \mathsf{neg}\left(\color{blue}{\frac{1}{2} \cdot \left(\frac{1}{{x}^{2}} \cdot x\right)}\right)\right)\right)\right) \]
      8. distribute-lft-neg-inN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \left(\frac{1}{{x}^{2}} \cdot x\right)}\right)\right)\right) \]
      9. associate-*l/N/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \color{blue}{\frac{1 \cdot x}{{x}^{2}}}\right)\right)\right) \]
      10. *-lft-identityN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \frac{\color{blue}{x}}{{x}^{2}}\right)\right)\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \frac{x}{\color{blue}{x \cdot x}}\right)\right)\right) \]
      12. associate-/r*N/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \color{blue}{\frac{\frac{x}{x}}{x}}\right)\right)\right) \]
      13. *-inversesN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \frac{\color{blue}{1}}{x}\right)\right)\right) \]
      14. associate-*r/N/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \color{blue}{\frac{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot 1}{x}}\right)\right)\right) \]
      15. metadata-evalN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \frac{\color{blue}{\frac{-1}{2}} \cdot 1}{x}\right)\right)\right) \]
      16. metadata-evalN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \frac{\color{blue}{\frac{-1}{2}}}{x}\right)\right)\right) \]
      17. metadata-evalN/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \frac{\color{blue}{\mathsf{neg}\left(\frac{1}{2}\right)}}{x}\right)\right)\right) \]
      18. /-lowering-/.f64N/A

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \color{blue}{\frac{\mathsf{neg}\left(\frac{1}{2}\right)}{x}}\right)\right)\right) \]
      19. metadata-eval98.9

        \[\leadsto -\log \left(\mathsf{fma}\left(-2, x, \frac{\color{blue}{-0.5}}{x}\right)\right) \]
    9. Simplified98.9%

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

    if -1.05000000000000004 < x < 1.32000000000000006

    1. Initial program 8.4%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
    4. Step-by-step derivation
      1. *-lowering-*.f64N/A

        \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
      2. +-commutativeN/A

        \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
      3. accelerator-lowering-fma.f64N/A

        \[\leadsto x \cdot \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right)} \]
      4. unpow2N/A

        \[\leadsto x \cdot \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto x \cdot \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right) \]
      6. sub-negN/A

        \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, 1\right) \]
      7. unpow2N/A

        \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \frac{3}{40} \cdot \color{blue}{\left(x \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
      8. associate-*r*N/A

        \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\left(\frac{3}{40} \cdot x\right) \cdot x} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
      9. *-commutativeN/A

        \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{x \cdot \left(\frac{3}{40} \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
      10. metadata-evalN/A

        \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, x \cdot \left(\frac{3}{40} \cdot x\right) + \color{blue}{\frac{-1}{6}}, 1\right) \]
      11. accelerator-lowering-fma.f64N/A

        \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x, \frac{3}{40} \cdot x, \frac{-1}{6}\right)}, 1\right) \]
      12. *-commutativeN/A

        \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{3}{40}}, \frac{-1}{6}\right), 1\right) \]
      13. *-lowering-*.f64100.0

        \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.075}, -0.16666666666666666\right), 1\right) \]
    5. Simplified100.0%

      \[\leadsto \color{blue}{x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)} \]

    if 1.32000000000000006 < x

    1. Initial program 38.8%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \log \left(x + \color{blue}{x}\right) \]
    4. Step-by-step derivation
      1. Simplified100.0%

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

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;0 - \log \left(\mathsf{fma}\left(-2, x, \frac{-0.5}{x}\right)\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \]
    7. Add Preprocessing

    Alternative 2: 99.5% accurate, 1.1× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;0 - \log \left(x \cdot -2\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.3)
       (- 0.0 (log (* x -2.0)))
       (if (<= x 1.32)
         (* x (fma (* x x) (fma x (* x 0.075) -0.16666666666666666) 1.0))
         (log (+ x x)))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = 0.0 - log((x * -2.0));
    	} else if (x <= 1.32) {
    		tmp = x * fma((x * x), fma(x, (x * 0.075), -0.16666666666666666), 1.0);
    	} else {
    		tmp = log((x + x));
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.3)
    		tmp = Float64(0.0 - log(Float64(x * -2.0)));
    	elseif (x <= 1.32)
    		tmp = Float64(x * fma(Float64(x * x), fma(x, Float64(x * 0.075), -0.16666666666666666), 1.0));
    	else
    		tmp = log(Float64(x + x));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[x, -1.3], N[(0.0 - N[Log[N[(x * -2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.32], N[(x * N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.3:\\
    \;\;\;\;0 - \log \left(x \cdot -2\right)\\
    
    \mathbf{elif}\;x \leq 1.32:\\
    \;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\log \left(x + x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.30000000000000004

      1. Initial program 3.8%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      2. Add Preprocessing
      3. Taylor expanded in x around -inf

        \[\leadsto \log \color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)} \]
      4. Step-by-step derivation
        1. /-lowering-/.f6498.8

          \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
      5. Simplified98.8%

        \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
      6. Step-by-step derivation
        1. clear-numN/A

          \[\leadsto \log \color{blue}{\left(\frac{1}{\frac{x}{\frac{-1}{2}}}\right)} \]
        2. log-recN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(\log \left(\frac{x}{\frac{-1}{2}}\right)\right)} \]
        3. neg-lowering-neg.f64N/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(\log \left(\frac{x}{\frac{-1}{2}}\right)\right)} \]
        4. log-lowering-log.f64N/A

          \[\leadsto \mathsf{neg}\left(\color{blue}{\log \left(\frac{x}{\frac{-1}{2}}\right)}\right) \]
        5. div-invN/A

          \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(x \cdot \frac{1}{\frac{-1}{2}}\right)}\right) \]
        6. *-lowering-*.f64N/A

          \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(x \cdot \frac{1}{\frac{-1}{2}}\right)}\right) \]
        7. metadata-eval98.8

          \[\leadsto -\log \left(x \cdot \color{blue}{-2}\right) \]
      7. Applied egg-rr98.8%

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

      if -1.30000000000000004 < x < 1.32000000000000006

      1. Initial program 8.4%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
      4. Step-by-step derivation
        1. *-lowering-*.f64N/A

          \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
        2. +-commutativeN/A

          \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
        3. accelerator-lowering-fma.f64N/A

          \[\leadsto x \cdot \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right)} \]
        4. unpow2N/A

          \[\leadsto x \cdot \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right) \]
        5. *-lowering-*.f64N/A

          \[\leadsto x \cdot \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right) \]
        6. sub-negN/A

          \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, 1\right) \]
        7. unpow2N/A

          \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \frac{3}{40} \cdot \color{blue}{\left(x \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
        8. associate-*r*N/A

          \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\left(\frac{3}{40} \cdot x\right) \cdot x} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
        9. *-commutativeN/A

          \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{x \cdot \left(\frac{3}{40} \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
        10. metadata-evalN/A

          \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, x \cdot \left(\frac{3}{40} \cdot x\right) + \color{blue}{\frac{-1}{6}}, 1\right) \]
        11. accelerator-lowering-fma.f64N/A

          \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x, \frac{3}{40} \cdot x, \frac{-1}{6}\right)}, 1\right) \]
        12. *-commutativeN/A

          \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{3}{40}}, \frac{-1}{6}\right), 1\right) \]
        13. *-lowering-*.f64100.0

          \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.075}, -0.16666666666666666\right), 1\right) \]
      5. Simplified100.0%

        \[\leadsto \color{blue}{x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)} \]

      if 1.32000000000000006 < x

      1. Initial program 38.8%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf

        \[\leadsto \log \left(x + \color{blue}{x}\right) \]
      4. Step-by-step derivation
        1. Simplified100.0%

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

        \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;0 - \log \left(x \cdot -2\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \]
      7. Add Preprocessing

      Alternative 3: 82.7% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.55:\\ \;\;\;\;0 - \log \left(1 - x\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
      (FPCore (x)
       :precision binary64
       (if (<= x -1.55)
         (- 0.0 (log (- 1.0 x)))
         (if (<= x 1.32)
           (* x (fma (* x x) (fma x (* x 0.075) -0.16666666666666666) 1.0))
           (log (+ x x)))))
      double code(double x) {
      	double tmp;
      	if (x <= -1.55) {
      		tmp = 0.0 - log((1.0 - x));
      	} else if (x <= 1.32) {
      		tmp = x * fma((x * x), fma(x, (x * 0.075), -0.16666666666666666), 1.0);
      	} else {
      		tmp = log((x + x));
      	}
      	return tmp;
      }
      
      function code(x)
      	tmp = 0.0
      	if (x <= -1.55)
      		tmp = Float64(0.0 - log(Float64(1.0 - x)));
      	elseif (x <= 1.32)
      		tmp = Float64(x * fma(Float64(x * x), fma(x, Float64(x * 0.075), -0.16666666666666666), 1.0));
      	else
      		tmp = log(Float64(x + x));
      	end
      	return tmp
      end
      
      code[x_] := If[LessEqual[x, -1.55], N[(0.0 - N[Log[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.32], N[(x * N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;x \leq -1.55:\\
      \;\;\;\;0 - \log \left(1 - x\right)\\
      
      \mathbf{elif}\;x \leq 1.32:\\
      \;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\log \left(x + x\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if x < -1.55000000000000004

        1. Initial program 3.8%

          \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. +-commutativeN/A

            \[\leadsto \log \color{blue}{\left(\sqrt{x \cdot x + 1} + x\right)} \]
          2. +-lowering-+.f64N/A

            \[\leadsto \log \color{blue}{\left(\sqrt{x \cdot x + 1} + x\right)} \]
          3. sqrt-lowering-sqrt.f64N/A

            \[\leadsto \log \left(\color{blue}{\sqrt{x \cdot x + 1}} + x\right) \]
          4. accelerator-lowering-fma.f643.8

            \[\leadsto \log \left(\sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}} + x\right) \]
        4. Applied egg-rr3.8%

          \[\leadsto \log \color{blue}{\left(\sqrt{\mathsf{fma}\left(x, x, 1\right)} + x\right)} \]
        5. Step-by-step derivation
          1. flip-+N/A

            \[\leadsto \log \color{blue}{\left(\frac{\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot x}{\sqrt{x \cdot x + 1} - x}\right)} \]
          2. flip3--N/A

            \[\leadsto \log \left(\frac{\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot x}{\color{blue}{\frac{{\left(\sqrt{x \cdot x + 1}\right)}^{3} - {x}^{3}}{\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + \left(x \cdot x + \sqrt{x \cdot x + 1} \cdot x\right)}}}\right) \]
          3. associate-/r/N/A

            \[\leadsto \log \color{blue}{\left(\frac{\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot x}{{\left(\sqrt{x \cdot x + 1}\right)}^{3} - {x}^{3}} \cdot \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + \left(x \cdot x + \sqrt{x \cdot x + 1} \cdot x\right)\right)\right)} \]
          4. rem-square-sqrtN/A

            \[\leadsto \log \left(\frac{\color{blue}{\left(x \cdot x + 1\right)} - x \cdot x}{{\left(\sqrt{x \cdot x + 1}\right)}^{3} - {x}^{3}} \cdot \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + \left(x \cdot x + \sqrt{x \cdot x + 1} \cdot x\right)\right)\right) \]
          5. associate-+r-N/A

            \[\leadsto \log \left(\frac{\color{blue}{x \cdot x + \left(1 - x \cdot x\right)}}{{\left(\sqrt{x \cdot x + 1}\right)}^{3} - {x}^{3}} \cdot \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + \left(x \cdot x + \sqrt{x \cdot x + 1} \cdot x\right)\right)\right) \]
        6. Applied egg-rr50.1%

          \[\leadsto \color{blue}{-\log \left(\sqrt{\mathsf{fma}\left(x, x, 1\right)} - x\right)} \]
        7. Taylor expanded in x around 0

          \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(1 + -1 \cdot x\right)}\right) \]
        8. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \mathsf{neg}\left(\log \left(1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right) \]
          2. unsub-negN/A

            \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(1 - x\right)}\right) \]
          3. --lowering--.f6431.5

            \[\leadsto -\log \color{blue}{\left(1 - x\right)} \]
        9. Simplified31.5%

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

        if -1.55000000000000004 < x < 1.32000000000000006

        1. Initial program 8.4%

          \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
        4. Step-by-step derivation
          1. *-lowering-*.f64N/A

            \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
          2. +-commutativeN/A

            \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \]
          3. accelerator-lowering-fma.f64N/A

            \[\leadsto x \cdot \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right)} \]
          4. unpow2N/A

            \[\leadsto x \cdot \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right) \]
          5. *-lowering-*.f64N/A

            \[\leadsto x \cdot \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, 1\right) \]
          6. sub-negN/A

            \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{3}{40} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}, 1\right) \]
          7. unpow2N/A

            \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \frac{3}{40} \cdot \color{blue}{\left(x \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
          8. associate-*r*N/A

            \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\left(\frac{3}{40} \cdot x\right) \cdot x} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
          9. *-commutativeN/A

            \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{x \cdot \left(\frac{3}{40} \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), 1\right) \]
          10. metadata-evalN/A

            \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, x \cdot \left(\frac{3}{40} \cdot x\right) + \color{blue}{\frac{-1}{6}}, 1\right) \]
          11. accelerator-lowering-fma.f64N/A

            \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x, \frac{3}{40} \cdot x, \frac{-1}{6}\right)}, 1\right) \]
          12. *-commutativeN/A

            \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{3}{40}}, \frac{-1}{6}\right), 1\right) \]
          13. *-lowering-*.f64100.0

            \[\leadsto x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.075}, -0.16666666666666666\right), 1\right) \]
        5. Simplified100.0%

          \[\leadsto \color{blue}{x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)} \]

        if 1.32000000000000006 < x

        1. Initial program 38.8%

          \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
        2. Add Preprocessing
        3. Taylor expanded in x around inf

          \[\leadsto \log \left(x + \color{blue}{x}\right) \]
        4. Step-by-step derivation
          1. Simplified100.0%

            \[\leadsto \log \left(x + \color{blue}{x}\right) \]
        5. Recombined 3 regimes into one program.
        6. Final simplification82.3%

          \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.55:\\ \;\;\;\;0 - \log \left(1 - x\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \]
        7. Add Preprocessing

        Alternative 4: 75.9% accurate, 1.1× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
        (FPCore (x) :precision binary64 (if (<= x 1.25) x (log (+ x x))))
        double code(double x) {
        	double tmp;
        	if (x <= 1.25) {
        		tmp = x;
        	} else {
        		tmp = log((x + x));
        	}
        	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 + x))
            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 + x));
        	}
        	return tmp;
        }
        
        def code(x):
        	tmp = 0
        	if x <= 1.25:
        		tmp = x
        	else:
        		tmp = math.log((x + x))
        	return tmp
        
        function code(x)
        	tmp = 0.0
        	if (x <= 1.25)
        		tmp = x;
        	else
        		tmp = log(Float64(x + x));
        	end
        	return tmp
        end
        
        function tmp_2 = code(x)
        	tmp = 0.0;
        	if (x <= 1.25)
        		tmp = x;
        	else
        		tmp = log((x + x));
        	end
        	tmp_2 = tmp;
        end
        
        code[x_] := If[LessEqual[x, 1.25], x, N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x \leq 1.25:\\
        \;\;\;\;x\\
        
        \mathbf{else}:\\
        \;\;\;\;\log \left(x + x\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if x < 1.25

          1. Initial program 6.9%

            \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
          2. Add Preprocessing
          3. Taylor expanded in x around 0

            \[\leadsto \color{blue}{x} \]
          4. Step-by-step derivation
            1. Simplified68.3%

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

            if 1.25 < x

            1. Initial program 38.8%

              \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
            2. Add Preprocessing
            3. Taylor expanded in x around inf

              \[\leadsto \log \left(x + \color{blue}{x}\right) \]
            4. Step-by-step derivation
              1. Simplified100.0%

                \[\leadsto \log \left(x + \color{blue}{x}\right) \]
            5. Recombined 2 regimes into one program.
            6. Add Preprocessing

            Alternative 5: 52.5% accurate, 122.0× 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 14.0%

              \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
            2. Add Preprocessing
            3. Taylor expanded in x around 0

              \[\leadsto \color{blue}{x} \]
            4. Step-by-step derivation
              1. Simplified54.2%

                \[\leadsto \color{blue}{x} \]
              2. Add Preprocessing

              Developer Target 1: 29.1% accurate, 0.9× 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 2024197 
              (FPCore (x)
                :name "Hyperbolic arcsine"
                :precision binary64
              
                :alt
                (! :herbie-platform default (if (< x 0) (log (/ -1 (- x (sqrt (+ (* x x) 1))))) (log (+ x (sqrt (+ (* x x) 1))))))
              
                (log (+ x (sqrt (+ (* x x) 1.0)))))