Hyperbolic arcsine

Percentage Accurate: 16.8% → 99.7%
Time: 8.8s
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: 16.8% 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: 99.7% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.45:\\ \;\;\;\;\log \left(\frac{\frac{0.125}{x \cdot x} - 0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.45)
   (log (/ (- (/ 0.125 (* x x)) 0.5) x))
   (if (<= x 1.3)
     (fma (* (/ 1.0 (fma -2.7 (* x x) -6.0)) x) (* x x) x)
     (log (+ (- x (/ -0.5 x)) x)))))
double code(double x) {
	double tmp;
	if (x <= -1.45) {
		tmp = log((((0.125 / (x * x)) - 0.5) / x));
	} else if (x <= 1.3) {
		tmp = fma(((1.0 / fma(-2.7, (x * x), -6.0)) * x), (x * x), x);
	} else {
		tmp = log(((x - (-0.5 / x)) + x));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.45)
		tmp = log(Float64(Float64(Float64(0.125 / Float64(x * x)) - 0.5) / x));
	elseif (x <= 1.3)
		tmp = fma(Float64(Float64(1.0 / fma(-2.7, Float64(x * x), -6.0)) * x), Float64(x * x), x);
	else
		tmp = log(Float64(Float64(x - Float64(-0.5 / x)) + x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.45], N[Log[N[(N[(N[(0.125 / N[(x * x), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.3], N[(N[(N[(1.0 / N[(-2.7 * N[(x * x), $MachinePrecision] + -6.0), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] * N[(x * x), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(N[(x - N[(-0.5 / x), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.45:\\
\;\;\;\;\log \left(\frac{\frac{0.125}{x \cdot x} - 0.5}{x}\right)\\

\mathbf{elif}\;x \leq 1.3:\\
\;\;\;\;\mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.44999999999999996

    1. Initial program 2.5%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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. lower--.f64N/A

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

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

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

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

        \[\leadsto \log \left(\frac{\frac{\frac{1}{8}}{\color{blue}{x \cdot x}} - \frac{1}{2}}{x}\right) \]
      15. lower-*.f64100.0

        \[\leadsto \log \left(\frac{\frac{0.125}{\color{blue}{x \cdot x}} - 0.5}{x}\right) \]
    5. Applied rewrites100.0%

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

    if -1.44999999999999996 < x < 1.30000000000000004

    1. Initial program 9.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
      14. lower-*.f6498.5

        \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
    5. Applied rewrites98.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
    6. Step-by-step derivation
      1. Applied rewrites98.5%

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, 0.075, -0.16666666666666666\right) \cdot x, \color{blue}{x \cdot x}, x\right) \]
      2. Step-by-step derivation
        1. Applied rewrites98.5%

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

          \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{-27}{10} \cdot {x}^{2} - 6} \cdot x, x \cdot x, x\right) \]
        3. Step-by-step derivation
          1. Applied rewrites98.6%

            \[\leadsto \mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right) \]

          if 1.30000000000000004 < x

          1. Initial program 52.6%

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

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

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

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

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

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

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

              \[\leadsto \log \left(x + \left(x - \frac{\color{blue}{\frac{-1}{2}}}{x}\right)\right) \]
            16. lower-/.f64100.0

              \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{-0.5}{x}}\right)\right) \]
          5. Applied rewrites100.0%

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

          \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.45:\\ \;\;\;\;\log \left(\frac{\frac{0.125}{x \cdot x} - 0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\ \end{array} \]
        6. Add Preprocessing

        Alternative 2: 99.5% accurate, 0.9× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.9:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\ \end{array} \end{array} \]
        (FPCore (x)
         :precision binary64
         (if (<= x -1.9)
           (log (/ -0.5 x))
           (if (<= x 1.3)
             (fma (* (/ 1.0 (fma -2.7 (* x x) -6.0)) x) (* x x) x)
             (log (+ (- x (/ -0.5 x)) x)))))
        double code(double x) {
        	double tmp;
        	if (x <= -1.9) {
        		tmp = log((-0.5 / x));
        	} else if (x <= 1.3) {
        		tmp = fma(((1.0 / fma(-2.7, (x * x), -6.0)) * x), (x * x), x);
        	} else {
        		tmp = log(((x - (-0.5 / x)) + x));
        	}
        	return tmp;
        }
        
        function code(x)
        	tmp = 0.0
        	if (x <= -1.9)
        		tmp = log(Float64(-0.5 / x));
        	elseif (x <= 1.3)
        		tmp = fma(Float64(Float64(1.0 / fma(-2.7, Float64(x * x), -6.0)) * x), Float64(x * x), x);
        	else
        		tmp = log(Float64(Float64(x - Float64(-0.5 / x)) + x));
        	end
        	return tmp
        end
        
        code[x_] := If[LessEqual[x, -1.9], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.3], N[(N[(N[(1.0 / N[(-2.7 * N[(x * x), $MachinePrecision] + -6.0), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] * N[(x * x), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(N[(x - N[(-0.5 / x), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]], $MachinePrecision]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x \leq -1.9:\\
        \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\
        
        \mathbf{elif}\;x \leq 1.3:\\
        \;\;\;\;\mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right)\\
        
        \mathbf{else}:\\
        \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 3 regimes
        2. if x < -1.8999999999999999

          1. Initial program 2.5%

            \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
          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-/.f6499.7

              \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
          5. Applied rewrites99.7%

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

          if -1.8999999999999999 < x < 1.30000000000000004

          1. Initial program 9.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
            14. lower-*.f6498.5

              \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
          5. Applied rewrites98.5%

            \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
          6. Step-by-step derivation
            1. Applied rewrites98.5%

              \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, 0.075, -0.16666666666666666\right) \cdot x, \color{blue}{x \cdot x}, x\right) \]
            2. Step-by-step derivation
              1. Applied rewrites98.5%

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

                \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{-27}{10} \cdot {x}^{2} - 6} \cdot x, x \cdot x, x\right) \]
              3. Step-by-step derivation
                1. Applied rewrites98.6%

                  \[\leadsto \mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right) \]

                if 1.30000000000000004 < x

                1. Initial program 52.6%

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

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

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

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

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

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

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

                    \[\leadsto \log \left(x + \left(x - \frac{\color{blue}{\frac{-1}{2}}}{x}\right)\right) \]
                  16. lower-/.f64100.0

                    \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{-0.5}{x}}\right)\right) \]
                5. Applied rewrites100.0%

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

                \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.9:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\ \end{array} \]
              6. Add Preprocessing

              Alternative 3: 99.4% accurate, 1.0× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.9:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.9:\\ \;\;\;\;\mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(2 \cdot x\right)\\ \end{array} \end{array} \]
              (FPCore (x)
               :precision binary64
               (if (<= x -1.9)
                 (log (/ -0.5 x))
                 (if (<= x 1.9)
                   (fma (* (/ 1.0 (fma -2.7 (* x x) -6.0)) x) (* x x) x)
                   (log (* 2.0 x)))))
              double code(double x) {
              	double tmp;
              	if (x <= -1.9) {
              		tmp = log((-0.5 / x));
              	} else if (x <= 1.9) {
              		tmp = fma(((1.0 / fma(-2.7, (x * x), -6.0)) * x), (x * x), x);
              	} else {
              		tmp = log((2.0 * x));
              	}
              	return tmp;
              }
              
              function code(x)
              	tmp = 0.0
              	if (x <= -1.9)
              		tmp = log(Float64(-0.5 / x));
              	elseif (x <= 1.9)
              		tmp = fma(Float64(Float64(1.0 / fma(-2.7, Float64(x * x), -6.0)) * x), Float64(x * x), x);
              	else
              		tmp = log(Float64(2.0 * x));
              	end
              	return tmp
              end
              
              code[x_] := If[LessEqual[x, -1.9], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.9], N[(N[(N[(1.0 / N[(-2.7 * N[(x * x), $MachinePrecision] + -6.0), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] * N[(x * x), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(2.0 * x), $MachinePrecision]], $MachinePrecision]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              \mathbf{if}\;x \leq -1.9:\\
              \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\
              
              \mathbf{elif}\;x \leq 1.9:\\
              \;\;\;\;\mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right)\\
              
              \mathbf{else}:\\
              \;\;\;\;\log \left(2 \cdot x\right)\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 3 regimes
              2. if x < -1.8999999999999999

                1. Initial program 2.5%

                  \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
                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-/.f6499.7

                    \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
                5. Applied rewrites99.7%

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

                if -1.8999999999999999 < x < 1.8999999999999999

                1. Initial program 9.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

                    \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
                  14. lower-*.f6498.5

                    \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
                5. Applied rewrites98.5%

                  \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
                6. Step-by-step derivation
                  1. Applied rewrites98.5%

                    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, 0.075, -0.16666666666666666\right) \cdot x, \color{blue}{x \cdot x}, x\right) \]
                  2. Step-by-step derivation
                    1. Applied rewrites98.5%

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

                      \[\leadsto \mathsf{fma}\left(\frac{1}{\frac{-27}{10} \cdot {x}^{2} - 6} \cdot x, x \cdot x, x\right) \]
                    3. Step-by-step derivation
                      1. Applied rewrites98.6%

                        \[\leadsto \mathsf{fma}\left(\frac{1}{\mathsf{fma}\left(-2.7, x \cdot x, -6\right)} \cdot x, x \cdot x, x\right) \]

                      if 1.8999999999999999 < x

                      1. Initial program 52.6%

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

                        \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
                      4. Step-by-step derivation
                        1. lower-*.f6499.8

                          \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
                      5. Applied rewrites99.8%

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

                    Alternative 4: 75.0% accurate, 1.1× speedup?

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

                      1. Initial program 6.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                          \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
                        14. lower-*.f6460.8

                          \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
                      5. Applied rewrites60.8%

                        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
                      6. Step-by-step derivation
                        1. Applied rewrites60.8%

                          \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]
                        2. Step-by-step derivation
                          1. Applied rewrites60.8%

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

                            \[\leadsto 1 \cdot x \]
                          3. Step-by-step derivation
                            1. Applied rewrites61.3%

                              \[\leadsto 1 \cdot x \]

                            if 1.25 < x

                            1. Initial program 52.6%

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

                              \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
                            4. Step-by-step derivation
                              1. lower-*.f6499.8

                                \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
                            5. Applied rewrites99.8%

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

                          Alternative 5: 58.8% accurate, 1.1× speedup?

                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.6:\\ \;\;\;\;1 \cdot x\\ \mathbf{else}:\\ \;\;\;\;\log \left(1 + x\right)\\ \end{array} \end{array} \]
                          (FPCore (x) :precision binary64 (if (<= x 1.6) (* 1.0 x) (log (+ 1.0 x))))
                          double code(double x) {
                          	double tmp;
                          	if (x <= 1.6) {
                          		tmp = 1.0 * x;
                          	} else {
                          		tmp = log((1.0 + x));
                          	}
                          	return tmp;
                          }
                          
                          real(8) function code(x)
                              real(8), intent (in) :: x
                              real(8) :: tmp
                              if (x <= 1.6d0) then
                                  tmp = 1.0d0 * x
                              else
                                  tmp = log((1.0d0 + x))
                              end if
                              code = tmp
                          end function
                          
                          public static double code(double x) {
                          	double tmp;
                          	if (x <= 1.6) {
                          		tmp = 1.0 * x;
                          	} else {
                          		tmp = Math.log((1.0 + x));
                          	}
                          	return tmp;
                          }
                          
                          def code(x):
                          	tmp = 0
                          	if x <= 1.6:
                          		tmp = 1.0 * x
                          	else:
                          		tmp = math.log((1.0 + x))
                          	return tmp
                          
                          function code(x)
                          	tmp = 0.0
                          	if (x <= 1.6)
                          		tmp = Float64(1.0 * x);
                          	else
                          		tmp = log(Float64(1.0 + x));
                          	end
                          	return tmp
                          end
                          
                          function tmp_2 = code(x)
                          	tmp = 0.0;
                          	if (x <= 1.6)
                          		tmp = 1.0 * x;
                          	else
                          		tmp = log((1.0 + x));
                          	end
                          	tmp_2 = tmp;
                          end
                          
                          code[x_] := If[LessEqual[x, 1.6], N[(1.0 * x), $MachinePrecision], N[Log[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]]
                          
                          \begin{array}{l}
                          
                          \\
                          \begin{array}{l}
                          \mathbf{if}\;x \leq 1.6:\\
                          \;\;\;\;1 \cdot x\\
                          
                          \mathbf{else}:\\
                          \;\;\;\;\log \left(1 + x\right)\\
                          
                          
                          \end{array}
                          \end{array}
                          
                          Derivation
                          1. Split input into 2 regimes
                          2. if x < 1.6000000000000001

                            1. Initial program 6.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                                \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
                              14. lower-*.f6460.8

                                \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
                            5. Applied rewrites60.8%

                              \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
                            6. Step-by-step derivation
                              1. Applied rewrites60.8%

                                \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]
                              2. Step-by-step derivation
                                1. Applied rewrites60.8%

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

                                  \[\leadsto 1 \cdot x \]
                                3. Step-by-step derivation
                                  1. Applied rewrites61.3%

                                    \[\leadsto 1 \cdot x \]

                                  if 1.6000000000000001 < x

                                  1. Initial program 52.6%

                                    \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
                                  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 rewrites31.5%

                                      \[\leadsto \log \left(x + \color{blue}{1}\right) \]
                                  5. Recombined 2 regimes into one program.
                                  6. Final simplification55.8%

                                    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.6:\\ \;\;\;\;1 \cdot x\\ \mathbf{else}:\\ \;\;\;\;\log \left(1 + x\right)\\ \end{array} \]
                                  7. Add Preprocessing

                                  Alternative 6: 52.5% accurate, 20.3× speedup?

                                  \[\begin{array}{l} \\ 1 \cdot x \end{array} \]
                                  (FPCore (x) :precision binary64 (* 1.0 x))
                                  double code(double x) {
                                  	return 1.0 * x;
                                  }
                                  
                                  real(8) function code(x)
                                      real(8), intent (in) :: x
                                      code = 1.0d0 * x
                                  end function
                                  
                                  public static double code(double x) {
                                  	return 1.0 * x;
                                  }
                                  
                                  def code(x):
                                  	return 1.0 * x
                                  
                                  function code(x)
                                  	return Float64(1.0 * x)
                                  end
                                  
                                  function tmp = code(x)
                                  	tmp = 1.0 * x;
                                  end
                                  
                                  code[x_] := N[(1.0 * x), $MachinePrecision]
                                  
                                  \begin{array}{l}
                                  
                                  \\
                                  1 \cdot x
                                  \end{array}
                                  
                                  Derivation
                                  1. Initial program 14.9%

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

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

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

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

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

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

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

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

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

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

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

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

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

                                      \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
                                    14. lower-*.f6450.3

                                      \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
                                  5. Applied rewrites50.3%

                                    \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
                                  6. Step-by-step derivation
                                    1. Applied rewrites50.3%

                                      \[\leadsto \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(\color{blue}{0.075}, x \cdot x, -0.16666666666666666\right), x\right) \]
                                    2. Step-by-step derivation
                                      1. Applied rewrites50.3%

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

                                        \[\leadsto 1 \cdot x \]
                                      3. Step-by-step derivation
                                        1. Applied rewrites51.0%

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

                                        Developer Target 1: 28.4% 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 2024255 
                                        (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)))))