Hyperbolic arcsine

Percentage Accurate: 17.4% → 99.4%
Time: 11.1s
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: 17.4% 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: 99.4% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.25:\\ \;\;\;\;0 - \log \left(x \cdot -2\right)\\ \mathbf{elif}\;x \leq 0.95:\\ \;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\mathsf{fma}\left(x, 2, \frac{0.5}{x}\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.25)
   (- 0.0 (log (* x -2.0)))
   (if (<= x 0.95)
     (fma (* x (* x x)) -0.16666666666666666 x)
     (log (fma x 2.0 (/ 0.5 x))))))
double code(double x) {
	double tmp;
	if (x <= -1.25) {
		tmp = 0.0 - log((x * -2.0));
	} else if (x <= 0.95) {
		tmp = fma((x * (x * x)), -0.16666666666666666, x);
	} else {
		tmp = log(fma(x, 2.0, (0.5 / x)));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.25)
		tmp = Float64(0.0 - log(Float64(x * -2.0)));
	elseif (x <= 0.95)
		tmp = fma(Float64(x * Float64(x * x)), -0.16666666666666666, x);
	else
		tmp = log(fma(x, 2.0, Float64(0.5 / x)));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.25], N[(0.0 - N[Log[N[(x * -2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 0.95], N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666 + x), $MachinePrecision], N[Log[N[(x * 2.0 + N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.25:\\
\;\;\;\;0 - \log \left(x \cdot -2\right)\\

\mathbf{elif}\;x \leq 0.95:\\
\;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\

\mathbf{else}:\\
\;\;\;\;\log \left(\mathsf{fma}\left(x, 2, \frac{0.5}{x}\right)\right)\\


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

    1. Initial program 3.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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-/.f6499.0

        \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    5. Simplified99.0%

      \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    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-eval99.0

        \[\leadsto -\log \left(x \cdot \color{blue}{-2}\right) \]
    7. Applied egg-rr99.0%

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

    if -1.25 < x < 0.94999999999999996

    1. Initial program 7.9%

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

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

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

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

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

        \[\leadsto x \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot \frac{-1}{6} + 1\right) \]
      5. associate-*l*N/A

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

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

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

      \[\leadsto \color{blue}{x \cdot \mathsf{fma}\left(x, x \cdot -0.16666666666666666, 1\right)} \]
    6. Step-by-step derivation
      1. distribute-lft-inN/A

        \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) + x \cdot 1} \]
      2. *-rgt-identityN/A

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

        \[\leadsto x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)} + x \]
      4. associate-*r*N/A

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot \frac{-1}{6}} + x \]
      5. cube-multN/A

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

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \frac{-1}{6}, x\right)} \]
      7. cube-multN/A

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

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

        \[\leadsto \mathsf{fma}\left(x \cdot \color{blue}{\left(x \cdot x\right)}, -0.16666666666666666, x\right) \]
    7. Applied egg-rr100.0%

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

    if 0.94999999999999996 < x

    1. Initial program 50.9%

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

      \[\leadsto \log \color{blue}{\left(x \cdot \left(2 + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)} \]
    4. Step-by-step derivation
      1. distribute-rgt-inN/A

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \log \left(\mathsf{fma}\left(x, 2, \frac{\color{blue}{\frac{1}{2}}}{x}\right)\right) \]
      12. /-lowering-/.f64100.0

        \[\leadsto \log \left(\mathsf{fma}\left(x, 2, \color{blue}{\frac{0.5}{x}}\right)\right) \]
    5. Simplified100.0%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.25:\\ \;\;\;\;0 - \log \left(x \cdot -2\right)\\ \mathbf{elif}\;x \leq 0.95:\\ \;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\mathsf{fma}\left(x, 2, \frac{0.5}{x}\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.3% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.25:\\ \;\;\;\;0 - \log \left(x \cdot -2\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.25)
   (- 0.0 (log (* x -2.0)))
   (if (<= x 1.25) (fma (* x (* x x)) -0.16666666666666666 x) (log (+ x x)))))
double code(double x) {
	double tmp;
	if (x <= -1.25) {
		tmp = 0.0 - log((x * -2.0));
	} else if (x <= 1.25) {
		tmp = fma((x * (x * x)), -0.16666666666666666, x);
	} else {
		tmp = log((x + x));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.25)
		tmp = Float64(0.0 - log(Float64(x * -2.0)));
	elseif (x <= 1.25)
		tmp = fma(Float64(x * Float64(x * x)), -0.16666666666666666, x);
	else
		tmp = log(Float64(x + x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.25], N[(0.0 - N[Log[N[(x * -2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.25], N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666 + x), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.25:\\
\;\;\;\;0 - \log \left(x \cdot -2\right)\\

\mathbf{elif}\;x \leq 1.25:\\
\;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\

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


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

    1. Initial program 3.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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-/.f6499.0

        \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    5. Simplified99.0%

      \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    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-eval99.0

        \[\leadsto -\log \left(x \cdot \color{blue}{-2}\right) \]
    7. Applied egg-rr99.0%

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

    if -1.25 < x < 1.25

    1. Initial program 7.9%

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

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

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

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

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

        \[\leadsto x \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot \frac{-1}{6} + 1\right) \]
      5. associate-*l*N/A

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

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

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

      \[\leadsto \color{blue}{x \cdot \mathsf{fma}\left(x, x \cdot -0.16666666666666666, 1\right)} \]
    6. Step-by-step derivation
      1. distribute-lft-inN/A

        \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) + x \cdot 1} \]
      2. *-rgt-identityN/A

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

        \[\leadsto x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)} + x \]
      4. associate-*r*N/A

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot \frac{-1}{6}} + x \]
      5. cube-multN/A

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

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \frac{-1}{6}, x\right)} \]
      7. cube-multN/A

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

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

        \[\leadsto \mathsf{fma}\left(x \cdot \color{blue}{\left(x \cdot x\right)}, -0.16666666666666666, x\right) \]
    7. Applied egg-rr100.0%

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

    if 1.25 < x

    1. Initial program 50.9%

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

      \[\leadsto \log \left(x + \color{blue}{x}\right) \]
    4. Step-by-step derivation
      1. Simplified99.2%

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

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.25:\\ \;\;\;\;0 - \log \left(x \cdot -2\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \]
    7. Add Preprocessing

    Alternative 3: 82.1% accurate, 1.1× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.52:\\ \;\;\;\;0 - \log \left(1 - x\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.52)
       (- 0.0 (log (- 1.0 x)))
       (if (<= x 1.25) (fma (* x (* x x)) -0.16666666666666666 x) (log (+ x x)))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.52) {
    		tmp = 0.0 - log((1.0 - x));
    	} else if (x <= 1.25) {
    		tmp = fma((x * (x * x)), -0.16666666666666666, x);
    	} else {
    		tmp = log((x + x));
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.52)
    		tmp = Float64(0.0 - log(Float64(1.0 - x)));
    	elseif (x <= 1.25)
    		tmp = fma(Float64(x * Float64(x * x)), -0.16666666666666666, x);
    	else
    		tmp = log(Float64(x + x));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[x, -1.52], N[(0.0 - N[Log[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.25], N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666 + x), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.52:\\
    \;\;\;\;0 - \log \left(1 - x\right)\\
    
    \mathbf{elif}\;x \leq 1.25:\\
    \;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\log \left(x + x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.52

      1. Initial program 3.6%

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

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

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

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

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

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

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

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

          \[\leadsto \log \left(\frac{x \cdot x - \mathsf{fma}\left(x, x, 1\right)}{x - \color{blue}{\sqrt{x \cdot x + 1}}}\right) \]
        9. accelerator-lowering-fma.f643.5

          \[\leadsto \log \left(\frac{x \cdot x - \mathsf{fma}\left(x, x, 1\right)}{x - \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}}\right) \]
      4. Applied egg-rr3.5%

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

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

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

          \[\leadsto \color{blue}{\mathsf{neg}\left(\log \left(\frac{x - \sqrt{x \cdot x + 1}}{x \cdot x - \left(x \cdot x + 1\right)}\right)\right)} \]
        4. clear-numN/A

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

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

          \[\leadsto \mathsf{neg}\left(\log \left(\frac{\mathsf{neg}\left(\color{blue}{\left(0 - 1\right)}\right)}{\frac{x \cdot x - \left(x \cdot x + 1\right)}{x - \sqrt{x \cdot x + 1}}}\right)\right) \]
        7. +-inversesN/A

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

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

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

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

          \[\leadsto \mathsf{neg}\left(\log \left(\frac{\mathsf{neg}\left(\left(x \cdot x - \sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1}\right)\right)}{\color{blue}{x + \sqrt{x \cdot x + 1}}}\right)\right) \]
        12. distribute-neg-fracN/A

          \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(\mathsf{neg}\left(\frac{x \cdot x - \sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1}}{x + \sqrt{x \cdot x + 1}}\right)\right)}\right) \]
      6. Applied egg-rr61.9%

        \[\leadsto \color{blue}{-\log \left(0 - \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)} \]
      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--.f6431.2

          \[\leadsto -\log \color{blue}{\left(1 - x\right)} \]
      9. Simplified31.2%

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

      if -1.52 < x < 1.25

      1. Initial program 7.9%

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

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

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

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

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

          \[\leadsto x \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot \frac{-1}{6} + 1\right) \]
        5. associate-*l*N/A

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

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

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

        \[\leadsto \color{blue}{x \cdot \mathsf{fma}\left(x, x \cdot -0.16666666666666666, 1\right)} \]
      6. Step-by-step derivation
        1. distribute-lft-inN/A

          \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(x \cdot \frac{-1}{6}\right)\right) + x \cdot 1} \]
        2. *-rgt-identityN/A

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

          \[\leadsto x \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot \frac{-1}{6}\right)} + x \]
        4. associate-*r*N/A

          \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot \frac{-1}{6}} + x \]
        5. cube-multN/A

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

          \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \frac{-1}{6}, x\right)} \]
        7. cube-multN/A

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

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

          \[\leadsto \mathsf{fma}\left(x \cdot \color{blue}{\left(x \cdot x\right)}, -0.16666666666666666, x\right) \]
      7. Applied egg-rr100.0%

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

      if 1.25 < x

      1. Initial program 50.9%

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

        \[\leadsto \log \left(x + \color{blue}{x}\right) \]
      4. Step-by-step derivation
        1. Simplified99.2%

          \[\leadsto \log \left(x + \color{blue}{x}\right) \]
      5. Recombined 3 regimes into one program.
      6. Final simplification83.4%

        \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.52:\\ \;\;\;\;0 - \log \left(1 - x\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;\mathsf{fma}\left(x \cdot \left(x \cdot x\right), -0.16666666666666666, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \]
      7. Add Preprocessing

      Alternative 4: 75.3% 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 6.4%

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

          \[\leadsto \color{blue}{x} \]
        4. Step-by-step derivation
          1. Simplified68.5%

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

          if 1.25 < x

          1. Initial program 50.9%

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

            \[\leadsto \log \left(x + \color{blue}{x}\right) \]
          4. Step-by-step derivation
            1. Simplified99.2%

              \[\leadsto \log \left(x + \color{blue}{x}\right) \]
          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 18.8%

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

            \[\leadsto \color{blue}{x} \]
          4. Step-by-step derivation
            1. Simplified51.0%

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

            Developer Target 1: 29.7% 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 2024196 
            (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)))))