Hyperbolic arcsine

Percentage Accurate: 17.5% → 99.6%
Time: 10.3s
Alternatives: 6
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 6 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: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.02:\\ \;\;\;\;-\log \left(\mathsf{fma}\left(-2, x, \frac{-0.5}{x}\right)\right)\\ \mathbf{elif}\;x \leq 1.02:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\mathsf{fma}\left(x, 2, \frac{0.5}{x}\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.02)
   (- (log (fma -2.0 x (/ -0.5 x))))
   (if (<= x 1.02)
     (fma (fma x (* x 0.075) -0.16666666666666666) (* x (* x x)) x)
     (log (fma x 2.0 (/ 0.5 x))))))
double code(double x) {
	double tmp;
	if (x <= -1.02) {
		tmp = -log(fma(-2.0, x, (-0.5 / x)));
	} else if (x <= 1.02) {
		tmp = fma(fma(x, (x * 0.075), -0.16666666666666666), (x * (x * x)), x);
	} else {
		tmp = log(fma(x, 2.0, (0.5 / x)));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.02)
		tmp = Float64(-log(fma(-2.0, x, Float64(-0.5 / x))));
	elseif (x <= 1.02)
		tmp = fma(fma(x, Float64(x * 0.075), -0.16666666666666666), Float64(x * Float64(x * x)), x);
	else
		tmp = log(fma(x, 2.0, Float64(0.5 / x)));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.02], (-N[Log[N[(-2.0 * x + N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), If[LessEqual[x, 1.02], N[(N[(x * N[(x * 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] + 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 -1.02:\\
\;\;\;\;-\log \left(\mathsf{fma}\left(-2, x, \frac{-0.5}{x}\right)\right)\\

\mathbf{elif}\;x \leq 1.02:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), 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 < -1.02

    1. Initial program 3.4%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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.f643.4

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(\frac{{x}^{3} - {\left(\sqrt{x \cdot x + 1}\right)}^{3}}{\left(x \cdot x - \left(x \cdot x + 1\right)\right) \cdot \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + x \cdot \sqrt{x \cdot x + 1}\right)\right)}\right)}\right) \]
    6. Applied egg-rr56.0%

      \[\leadsto \color{blue}{-\log \left(\sqrt{\mathsf{fma}\left(x, x, 1\right)} - x\right)} \]
    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. unpow2N/A

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

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

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \left(\mathsf{neg}\left(\frac{1}{2}\right)\right) \cdot \color{blue}{\frac{\frac{1}{x} \cdot x}{x}}\right)\right)\right) \]
      12. lft-mult-inverseN/A

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

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

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

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

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

        \[\leadsto \mathsf{neg}\left(\log \left(\mathsf{fma}\left(-2, x, \color{blue}{\frac{\mathsf{neg}\left(\frac{1}{2}\right)}{x}}\right)\right)\right) \]
      18. metadata-eval99.8

        \[\leadsto -\log \left(\mathsf{fma}\left(-2, x, \frac{\color{blue}{-0.5}}{x}\right)\right) \]
    9. Simplified99.8%

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

    if -1.02 < x < 1.02

    1. Initial program 6.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. *-commutativeN/A

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

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \cdot x \]
      3. distribute-lft1-inN/A

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{3}{40} \cdot \color{blue}{\left(x \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), x \cdot {x}^{2}, x\right) \]
      10. associate-*r*N/A

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

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

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

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

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

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

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

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

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

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

    if 1.02 < x

    1. Initial program 54.4%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. Add Preprocessing

Alternative 2: 99.5% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;-\log \left(x \cdot -2\right)\\ \mathbf{elif}\;x \leq 1.02:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\mathsf{fma}\left(x, 2, \frac{0.5}{x}\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.3)
   (- (log (* x -2.0)))
   (if (<= x 1.02)
     (fma (fma x (* x 0.075) -0.16666666666666666) (* x (* x x)) x)
     (log (fma x 2.0 (/ 0.5 x))))))
double code(double x) {
	double tmp;
	if (x <= -1.3) {
		tmp = -log((x * -2.0));
	} else if (x <= 1.02) {
		tmp = fma(fma(x, (x * 0.075), -0.16666666666666666), (x * (x * x)), x);
	} else {
		tmp = log(fma(x, 2.0, (0.5 / x)));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.3)
		tmp = Float64(-log(Float64(x * -2.0)));
	elseif (x <= 1.02)
		tmp = fma(fma(x, Float64(x * 0.075), -0.16666666666666666), Float64(x * Float64(x * x)), x);
	else
		tmp = log(fma(x, 2.0, Float64(0.5 / x)));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.3], (-N[Log[N[(x * -2.0), $MachinePrecision]], $MachinePrecision]), If[LessEqual[x, 1.02], N[(N[(x * N[(x * 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] + 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 -1.3:\\
\;\;\;\;-\log \left(x \cdot -2\right)\\

\mathbf{elif}\;x \leq 1.02:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), 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 < -1.30000000000000004

    1. Initial program 3.4%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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-/.f6499.2

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

      \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    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-eval99.2

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

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

    if -1.30000000000000004 < x < 1.02

    1. Initial program 6.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. *-commutativeN/A

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

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \cdot x \]
      3. distribute-lft1-inN/A

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{3}{40} \cdot \color{blue}{\left(x \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), x \cdot {x}^{2}, x\right) \]
      10. associate-*r*N/A

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

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

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

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

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

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

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

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

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

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

    if 1.02 < x

    1. Initial program 54.4%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. Add Preprocessing

Alternative 3: 99.4% accurate, 1.1× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.3:\\
\;\;\;\;-\log \left(x \cdot -2\right)\\

\mathbf{elif}\;x \leq 1.32:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\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 3.4%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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-/.f6499.2

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

      \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    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-eval99.2

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

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

    if -1.30000000000000004 < x < 1.32000000000000006

    1. Initial program 6.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. *-commutativeN/A

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

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \cdot x \]
      3. distribute-lft1-inN/A

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{3}{40} \cdot \color{blue}{\left(x \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), x \cdot {x}^{2}, x\right) \]
      10. associate-*r*N/A

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

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

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

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

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

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

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

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

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

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

    if 1.32000000000000006 < x

    1. Initial program 54.4%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. Add Preprocessing

    Alternative 4: 81.9% accurate, 1.1× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.52:\\ \;\;\;\;-\log \left(1 - x\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.52)
       (- (log (- 1.0 x)))
       (if (<= x 1.32)
         (fma (fma x (* x 0.075) -0.16666666666666666) (* x (* x x)) x)
         (log (+ x x)))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.52) {
    		tmp = -log((1.0 - x));
    	} else if (x <= 1.32) {
    		tmp = fma(fma(x, (x * 0.075), -0.16666666666666666), (x * (x * x)), x);
    	} else {
    		tmp = log((x + x));
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.52)
    		tmp = Float64(-log(Float64(1.0 - x)));
    	elseif (x <= 1.32)
    		tmp = fma(fma(x, Float64(x * 0.075), -0.16666666666666666), Float64(x * Float64(x * x)), x);
    	else
    		tmp = log(Float64(x + x));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[x, -1.52], (-N[Log[N[(1.0 - x), $MachinePrecision]], $MachinePrecision]), If[LessEqual[x, 1.32], N[(N[(x * N[(x * 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.52:\\
    \;\;\;\;-\log \left(1 - x\right)\\
    
    \mathbf{elif}\;x \leq 1.32:\\
    \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), 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 3.4%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      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.f643.4

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(\frac{{x}^{3} - {\left(\sqrt{x \cdot x + 1}\right)}^{3}}{\left(x \cdot x - \left(x \cdot x + 1\right)\right) \cdot \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} + x \cdot \sqrt{x \cdot x + 1}\right)\right)}\right)}\right) \]
      6. Applied egg-rr56.0%

        \[\leadsto \color{blue}{-\log \left(\sqrt{\mathsf{fma}\left(x, x, 1\right)} - x\right)} \]
      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--.f6431.3

          \[\leadsto -\log \color{blue}{\left(1 - x\right)} \]
      9. Simplified31.3%

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

      if -1.52 < x < 1.32000000000000006

      1. Initial program 6.6%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      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. *-commutativeN/A

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

          \[\leadsto \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right)} \cdot x \]
        3. distribute-lft1-inN/A

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{3}{40} \cdot \color{blue}{\left(x \cdot x\right)} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right), x \cdot {x}^{2}, x\right) \]
        10. associate-*r*N/A

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

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

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

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

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

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

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

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

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

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

      if 1.32000000000000006 < x

      1. Initial program 54.4%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      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. Add Preprocessing

      Alternative 5: 74.9% 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 5.6%

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

          \[\leadsto \color{blue}{x} \]
        4. Step-by-step derivation
          1. Simplified72.1%

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

          if 1.25 < x

          1. Initial program 54.4%

            \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
          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 6: 52.3% 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 18.6%

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

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

              \[\leadsto \color{blue}{x} \]
            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 2024204 
            (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)))))