Hyperbolic arcsine

Percentage Accurate: 18.5% → 99.6%
Time: 10.8s
Alternatives: 6
Speedup: 20.3×

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: 18.5% 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?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.1:\\ \;\;\;\;\log \left(\frac{-0.5 + \frac{0.125}{x \cdot x}}{x}\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + \left(x - \frac{-0.5}{x}\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.1)
   (log (/ (+ -0.5 (/ 0.125 (* x x))) x))
   (if (<= x 1.05)
     (fma
      (fma
       (* x x)
       (fma x (* x -0.044642857142857144) 0.075)
       -0.16666666666666666)
      (* x (* x x))
      x)
     (log (+ x (- x (/ -0.5 x)))))))
double code(double x) {
	double tmp;
	if (x <= -1.1) {
		tmp = log(((-0.5 + (0.125 / (x * x))) / x));
	} else if (x <= 1.05) {
		tmp = fma(fma((x * x), fma(x, (x * -0.044642857142857144), 0.075), -0.16666666666666666), (x * (x * x)), x);
	} else {
		tmp = log((x + (x - (-0.5 / x))));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.1)
		tmp = log(Float64(Float64(-0.5 + Float64(0.125 / Float64(x * x))) / x));
	elseif (x <= 1.05)
		tmp = fma(fma(Float64(x * x), fma(x, Float64(x * -0.044642857142857144), 0.075), -0.16666666666666666), Float64(x * Float64(x * x)), x);
	else
		tmp = log(Float64(x + Float64(x - Float64(-0.5 / x))));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.1], N[Log[N[(N[(-0.5 + N[(0.125 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.05], N[(N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * -0.044642857142857144), $MachinePrecision] + 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x + N[(x - N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.1:\\
\;\;\;\;\log \left(\frac{-0.5 + \frac{0.125}{x \cdot x}}{x}\right)\\

\mathbf{elif}\;x \leq 1.05:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.1000000000000001

    1. Initial program 4.6%

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

      \[\leadsto \log \color{blue}{\left(-1 \cdot \frac{\frac{1}{2} - \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

        \[\leadsto \log \color{blue}{\left(\frac{-1 \cdot \left(\frac{1}{2} - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}{x}\right)} \]
      2. mul-1-negN/A

        \[\leadsto \log \left(\frac{\color{blue}{\mathsf{neg}\left(\left(\frac{1}{2} - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)\right)}}{x}\right) \]
      3. neg-sub0N/A

        \[\leadsto \log \left(\frac{\color{blue}{0 - \left(\frac{1}{2} - \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}}{x}\right) \]
      4. associate--r-N/A

        \[\leadsto \log \left(\frac{\color{blue}{\left(0 - \frac{1}{2}\right) + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}}{x}\right) \]
      5. metadata-evalN/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{-1}{2}} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right) \]
      6. +-commutativeN/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{1}{8} \cdot \frac{1}{{x}^{2}} + \frac{-1}{2}}}{x}\right) \]
      7. metadata-evalN/A

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

        \[\leadsto \log \left(\frac{\color{blue}{\frac{1}{8} \cdot \frac{1}{{x}^{2}} - \frac{1}{2}}}{x}\right) \]
      9. lower-/.f64N/A

        \[\leadsto \log \color{blue}{\left(\frac{\frac{1}{8} \cdot \frac{1}{{x}^{2}} - \frac{1}{2}}{x}\right)} \]
      10. sub-negN/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{1}{8} \cdot \frac{1}{{x}^{2}} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}}{x}\right) \]
      11. metadata-evalN/A

        \[\leadsto \log \left(\frac{\frac{1}{8} \cdot \frac{1}{{x}^{2}} + \color{blue}{\frac{-1}{2}}}{x}\right) \]
      12. +-commutativeN/A

        \[\leadsto \log \left(\frac{\color{blue}{\frac{-1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}}{x}\right) \]
      13. lower-+.f64N/A

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

        \[\leadsto \log \left(\frac{\frac{-1}{2} + \color{blue}{\frac{\frac{1}{8} \cdot 1}{{x}^{2}}}}{x}\right) \]
      15. metadata-evalN/A

        \[\leadsto \log \left(\frac{\frac{-1}{2} + \frac{\color{blue}{\frac{1}{8}}}{{x}^{2}}}{x}\right) \]
      16. lower-/.f64N/A

        \[\leadsto \log \left(\frac{\frac{-1}{2} + \color{blue}{\frac{\frac{1}{8}}{{x}^{2}}}}{x}\right) \]
      17. unpow2N/A

        \[\leadsto \log \left(\frac{\frac{-1}{2} + \frac{\frac{1}{8}}{\color{blue}{x \cdot x}}}{x}\right) \]
      18. lower-*.f6499.2

        \[\leadsto \log \left(\frac{-0.5 + \frac{0.125}{\color{blue}{x \cdot x}}}{x}\right) \]
    5. Applied rewrites99.2%

      \[\leadsto \log \color{blue}{\left(\frac{-0.5 + \frac{0.125}{x \cdot x}}{x}\right)} \]

    if -1.1000000000000001 < x < 1.05000000000000004

    1. Initial program 9.1%

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

      \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) + 1\right)} \]
      2. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right) \cdot x + 1 \cdot x} \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)} + 1 \cdot x \]
      4. associate-*r*N/A

        \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)} + 1 \cdot x \]
      5. *-commutativeN/A

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) \cdot \left(x \cdot {x}^{2}\right)} + 1 \cdot x \]
      6. *-lft-identityN/A

        \[\leadsto \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) \cdot \left(x \cdot {x}^{2}\right) + \color{blue}{x} \]
      7. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}, x \cdot {x}^{2}, x\right)} \]
    5. Applied rewrites99.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)} \]

    if 1.05000000000000004 < x

    1. Initial program 65.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \log \left(x + \left(x - \frac{\color{blue}{\frac{-1}{2}}}{x}\right)\right) \]
      15. lower-/.f6498.7

        \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{-0.5}{x}}\right)\right) \]
    5. Applied rewrites98.7%

      \[\leadsto \log \left(x + \color{blue}{\left(x - \frac{-0.5}{x}\right)}\right) \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 2: 99.5% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.26:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + \left(x - \frac{-0.5}{x}\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.26)
   (log (/ -0.5 x))
   (if (<= x 1.05)
     (fma
      (fma
       (* x x)
       (fma x (* x -0.044642857142857144) 0.075)
       -0.16666666666666666)
      (* x (* x x))
      x)
     (log (+ x (- x (/ -0.5 x)))))))
double code(double x) {
	double tmp;
	if (x <= -1.26) {
		tmp = log((-0.5 / x));
	} else if (x <= 1.05) {
		tmp = fma(fma((x * x), fma(x, (x * -0.044642857142857144), 0.075), -0.16666666666666666), (x * (x * x)), x);
	} else {
		tmp = log((x + (x - (-0.5 / x))));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.26)
		tmp = log(Float64(-0.5 / x));
	elseif (x <= 1.05)
		tmp = fma(fma(Float64(x * x), fma(x, Float64(x * -0.044642857142857144), 0.075), -0.16666666666666666), Float64(x * Float64(x * x)), x);
	else
		tmp = log(Float64(x + Float64(x - Float64(-0.5 / x))));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.26], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.05], N[(N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * -0.044642857142857144), $MachinePrecision] + 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x + N[(x - N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.26:\\
\;\;\;\;\log \left(\frac{-0.5}{x}\right)\\

\mathbf{elif}\;x \leq 1.05:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.26000000000000001

    1. Initial program 4.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. lower-/.f6498.5

        \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    5. Applied rewrites98.5%

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

    if -1.26000000000000001 < x < 1.05000000000000004

    1. Initial program 9.1%

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

      \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) + 1\right)} \]
      2. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right) \cdot x + 1 \cdot x} \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)} + 1 \cdot x \]
      4. associate-*r*N/A

        \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)} + 1 \cdot x \]
      5. *-commutativeN/A

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) \cdot \left(x \cdot {x}^{2}\right)} + 1 \cdot x \]
      6. *-lft-identityN/A

        \[\leadsto \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) \cdot \left(x \cdot {x}^{2}\right) + \color{blue}{x} \]
      7. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}, x \cdot {x}^{2}, x\right)} \]
    5. Applied rewrites99.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)} \]

    if 1.05000000000000004 < x

    1. Initial program 65.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \log \left(x + \left(x - \frac{\color{blue}{\frac{-1}{2}}}{x}\right)\right) \]
      15. lower-/.f6498.7

        \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{-0.5}{x}}\right)\right) \]
    5. Applied rewrites98.7%

      \[\leadsto \log \left(x + \color{blue}{\left(x - \frac{-0.5}{x}\right)}\right) \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 3: 99.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.26:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.26)
   (log (/ -0.5 x))
   (if (<= x 1.3)
     (fma
      (fma
       (* x x)
       (fma x (* x -0.044642857142857144) 0.075)
       -0.16666666666666666)
      (* x (* x x))
      x)
     (log (* x 2.0)))))
double code(double x) {
	double tmp;
	if (x <= -1.26) {
		tmp = log((-0.5 / x));
	} else if (x <= 1.3) {
		tmp = fma(fma((x * x), fma(x, (x * -0.044642857142857144), 0.075), -0.16666666666666666), (x * (x * x)), x);
	} else {
		tmp = log((x * 2.0));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.26)
		tmp = log(Float64(-0.5 / x));
	elseif (x <= 1.3)
		tmp = fma(fma(Float64(x * x), fma(x, Float64(x * -0.044642857142857144), 0.075), -0.16666666666666666), Float64(x * Float64(x * x)), x);
	else
		tmp = log(Float64(x * 2.0));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.26], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.3], N[(N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * -0.044642857142857144), $MachinePrecision] + 0.075), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.26:\\
\;\;\;\;\log \left(\frac{-0.5}{x}\right)\\

\mathbf{elif}\;x \leq 1.3:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.26000000000000001

    1. Initial program 4.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. lower-/.f6498.5

        \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
    5. Applied rewrites98.5%

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

    if -1.26000000000000001 < x < 1.30000000000000004

    1. Initial program 9.1%

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

      \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x \cdot \color{blue}{\left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) + 1\right)} \]
      2. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right) \cdot x + 1 \cdot x} \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{x \cdot \left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)} + 1 \cdot x \]
      4. associate-*r*N/A

        \[\leadsto \color{blue}{\left(x \cdot {x}^{2}\right) \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)} + 1 \cdot x \]
      5. *-commutativeN/A

        \[\leadsto \color{blue}{\left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) \cdot \left(x \cdot {x}^{2}\right)} + 1 \cdot x \]
      6. *-lft-identityN/A

        \[\leadsto \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right) \cdot \left(x \cdot {x}^{2}\right) + \color{blue}{x} \]
      7. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}, x \cdot {x}^{2}, x\right)} \]
    5. Applied rewrites99.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.044642857142857144, 0.075\right), -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)} \]

    if 1.30000000000000004 < x

    1. Initial program 65.4%

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

      \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
      2. lower-*.f6497.5

        \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
    5. Applied rewrites97.5%

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

Alternative 4: 76.2% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;x \cdot 1\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \end{array} \]
(FPCore (x) :precision binary64 (if (<= x 1.25) (* x 1.0) (log (* x 2.0))))
double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = x * 1.0;
	} else {
		tmp = log((x * 2.0));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.25d0) then
        tmp = x * 1.0d0
    else
        tmp = log((x * 2.0d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = x * 1.0;
	} else {
		tmp = Math.log((x * 2.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.25:
		tmp = x * 1.0
	else:
		tmp = math.log((x * 2.0))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.25)
		tmp = Float64(x * 1.0);
	else
		tmp = log(Float64(x * 2.0));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.25)
		tmp = x * 1.0;
	else
		tmp = log((x * 2.0));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.25], N[(x * 1.0), $MachinePrecision], N[Log[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.25:\\
\;\;\;\;x \cdot 1\\

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


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

    1. Initial program 7.9%

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

      \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
    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. lower-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. lower-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. lower-*.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. lower-*.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. lower-*.f6472.5

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \color{blue}{\left(x \cdot x\right)}, x\right) \]
    5. Applied rewrites72.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)} \]
    6. Step-by-step derivation
      1. Applied rewrites72.5%

        \[\leadsto \mathsf{fma}\left(x \cdot \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), \color{blue}{x \cdot x}, x\right) \]
      2. Step-by-step derivation
        1. Applied rewrites72.5%

          \[\leadsto \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right) \cdot \color{blue}{x} \]
        2. Taylor expanded in x around 0

          \[\leadsto 1 \cdot x \]
        3. Step-by-step derivation
          1. Applied rewrites72.6%

            \[\leadsto 1 \cdot x \]

          if 1.25 < x

          1. Initial program 65.4%

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

            \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
          4. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
            2. lower-*.f6497.5

              \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
          5. Applied rewrites97.5%

            \[\leadsto \log \color{blue}{\left(x \cdot 2\right)} \]
        4. Recombined 2 regimes into one program.
        5. Final simplification78.0%

          \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;x \cdot 1\\ \mathbf{else}:\\ \;\;\;\;\log \left(x \cdot 2\right)\\ \end{array} \]
        6. Add Preprocessing

        Alternative 5: 59.3% accurate, 1.1× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.55:\\ \;\;\;\;x \cdot 1\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + 1\right)\\ \end{array} \end{array} \]
        (FPCore (x) :precision binary64 (if (<= x 1.55) (* x 1.0) (log (+ x 1.0))))
        double code(double x) {
        	double tmp;
        	if (x <= 1.55) {
        		tmp = x * 1.0;
        	} else {
        		tmp = log((x + 1.0));
        	}
        	return tmp;
        }
        
        real(8) function code(x)
            real(8), intent (in) :: x
            real(8) :: tmp
            if (x <= 1.55d0) then
                tmp = x * 1.0d0
            else
                tmp = log((x + 1.0d0))
            end if
            code = tmp
        end function
        
        public static double code(double x) {
        	double tmp;
        	if (x <= 1.55) {
        		tmp = x * 1.0;
        	} else {
        		tmp = Math.log((x + 1.0));
        	}
        	return tmp;
        }
        
        def code(x):
        	tmp = 0
        	if x <= 1.55:
        		tmp = x * 1.0
        	else:
        		tmp = math.log((x + 1.0))
        	return tmp
        
        function code(x)
        	tmp = 0.0
        	if (x <= 1.55)
        		tmp = Float64(x * 1.0);
        	else
        		tmp = log(Float64(x + 1.0));
        	end
        	return tmp
        end
        
        function tmp_2 = code(x)
        	tmp = 0.0;
        	if (x <= 1.55)
        		tmp = x * 1.0;
        	else
        		tmp = log((x + 1.0));
        	end
        	tmp_2 = tmp;
        end
        
        code[x_] := If[LessEqual[x, 1.55], N[(x * 1.0), $MachinePrecision], N[Log[N[(x + 1.0), $MachinePrecision]], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x \leq 1.55:\\
        \;\;\;\;x \cdot 1\\
        
        \mathbf{else}:\\
        \;\;\;\;\log \left(x + 1\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if x < 1.55000000000000004

          1. Initial program 7.9%

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

            \[\leadsto \color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)} \]
          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. lower-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. lower-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. lower-*.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. lower-*.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. lower-*.f6472.5

              \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \color{blue}{\left(x \cdot x\right)}, x\right) \]
          5. Applied rewrites72.5%

            \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)} \]
          6. Step-by-step derivation
            1. Applied rewrites72.5%

              \[\leadsto \mathsf{fma}\left(x \cdot \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), \color{blue}{x \cdot x}, x\right) \]
            2. Step-by-step derivation
              1. Applied rewrites72.5%

                \[\leadsto \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right) \cdot \color{blue}{x} \]
              2. Taylor expanded in x around 0

                \[\leadsto 1 \cdot x \]
              3. Step-by-step derivation
                1. Applied rewrites72.6%

                  \[\leadsto 1 \cdot x \]

                if 1.55000000000000004 < x

                1. Initial program 65.4%

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

                  \[\leadsto \log \left(x + \color{blue}{1}\right) \]
                4. Step-by-step derivation
                  1. Applied rewrites30.6%

                    \[\leadsto \log \left(x + \color{blue}{1}\right) \]
                5. Recombined 2 regimes into one program.
                6. Final simplification63.4%

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

                Alternative 6: 52.9% accurate, 20.3× speedup?

                \[\begin{array}{l} \\ x \cdot 1 \end{array} \]
                (FPCore (x) :precision binary64 (* x 1.0))
                double code(double x) {
                	return x * 1.0;
                }
                
                real(8) function code(x)
                    real(8), intent (in) :: x
                    code = x * 1.0d0
                end function
                
                public static double code(double x) {
                	return x * 1.0;
                }
                
                def code(x):
                	return x * 1.0
                
                function code(x)
                	return Float64(x * 1.0)
                end
                
                function tmp = code(x)
                	tmp = x * 1.0;
                end
                
                code[x_] := N[(x * 1.0), $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                x \cdot 1
                \end{array}
                
                Derivation
                1. Initial program 20.5%

                  \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
                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. lower-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. lower-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. lower-*.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. lower-*.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. lower-*.f6457.5

                    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \color{blue}{\left(x \cdot x\right)}, x\right) \]
                5. Applied rewrites57.5%

                  \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), x \cdot \left(x \cdot x\right), x\right)} \]
                6. Step-by-step derivation
                  1. Applied rewrites57.5%

                    \[\leadsto \mathsf{fma}\left(x \cdot \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), \color{blue}{x \cdot x}, x\right) \]
                  2. Step-by-step derivation
                    1. Applied rewrites57.5%

                      \[\leadsto \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.075, -0.16666666666666666\right), 1\right) \cdot \color{blue}{x} \]
                    2. Taylor expanded in x around 0

                      \[\leadsto 1 \cdot x \]
                    3. Step-by-step derivation
                      1. Applied rewrites58.1%

                        \[\leadsto 1 \cdot x \]
                      2. Final simplification58.1%

                        \[\leadsto x \cdot 1 \]
                      3. Add Preprocessing

                      Developer Target 1: 30.1% 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 2024221 
                      (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)))))