Hyperbolic arcsine

Percentage Accurate: 17.5% → 99.6%
Time: 8.5s
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: 17.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \log \left(x + \sqrt{x \cdot x + 1}\right) \end{array} \]
(FPCore (x) :precision binary64 (log (+ x (sqrt (+ (* x x) 1.0)))))
double code(double x) {
	return log((x + sqrt(((x * x) + 1.0))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((x + sqrt(((x * x) + 1.0d0))))
end function
public static double code(double x) {
	return Math.log((x + Math.sqrt(((x * x) + 1.0))));
}
def code(x):
	return math.log((x + math.sqrt(((x * x) + 1.0))))
function code(x)
	return log(Float64(x + sqrt(Float64(Float64(x * x) + 1.0))))
end
function tmp = code(x)
	tmp = log((x + sqrt(((x * x) + 1.0))));
end
code[x_] := N[Log[N[(x + N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\log \left(x + \sqrt{x \cdot x + 1}\right)
\end{array}

Alternative 1: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.15:\\ \;\;\;\;\log \left(\frac{\frac{0.125}{x \cdot x} - 0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \left(x \cdot x\right) \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.15)
   (log (/ (- (/ 0.125 (* x x)) 0.5) x))
   (if (<= x 1.05)
     (fma (fma 0.075 (* x x) -0.16666666666666666) (* (* x x) x) x)
     (log (+ (- x (/ -0.5 x)) x)))))
double code(double x) {
	double tmp;
	if (x <= -1.15) {
		tmp = log((((0.125 / (x * x)) - 0.5) / x));
	} else if (x <= 1.05) {
		tmp = fma(fma(0.075, (x * x), -0.16666666666666666), ((x * x) * x), x);
	} else {
		tmp = log(((x - (-0.5 / x)) + x));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -1.15)
		tmp = log(Float64(Float64(Float64(0.125 / Float64(x * x)) - 0.5) / x));
	elseif (x <= 1.05)
		tmp = fma(fma(0.075, Float64(x * x), -0.16666666666666666), Float64(Float64(x * x) * x), x);
	else
		tmp = log(Float64(Float64(x - Float64(-0.5 / x)) + x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -1.15], N[Log[N[(N[(N[(0.125 / N[(x * x), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.05], N[(N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 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 -1.15:\\
\;\;\;\;\log \left(\frac{\frac{0.125}{x \cdot x} - 0.5}{x}\right)\\

\mathbf{elif}\;x \leq 1.05:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \left(x \cdot x\right) \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 < -1.1499999999999999

    1. Initial program 4.2%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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-*.f6499.3

        \[\leadsto \log \left(\frac{\frac{0.125}{\color{blue}{x \cdot x}} - 0.5}{x}\right) \]
    5. Applied rewrites99.3%

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

    if -1.1499999999999999 < x < 1.05000000000000004

    1. Initial program 6.7%

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x \cdot x, 1\right) \cdot x} \]
    6. Step-by-step derivation
      1. Applied rewrites100.0%

        \[\leadsto \mathsf{fma}\left(\left(\mathsf{fma}\left(x \cdot x, 0.075, -0.16666666666666666\right) \cdot x\right) \cdot x, \color{blue}{x}, 1 \cdot x\right) \]
      2. Step-by-step derivation
        1. Applied rewrites100.0%

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

        if 1.05000000000000004 < x

        1. Initial program 49.2%

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

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

        \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.15:\\ \;\;\;\;\log \left(\frac{\frac{0.125}{x \cdot x} - 0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \left(x \cdot x\right) \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\ \end{array} \]
      5. Add Preprocessing

      Alternative 2: 99.6% accurate, 0.9× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.35:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \left(x \cdot x\right) \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\ \end{array} \end{array} \]
      (FPCore (x)
       :precision binary64
       (if (<= x -1.35)
         (log (/ -0.5 x))
         (if (<= x 1.05)
           (fma (fma 0.075 (* x x) -0.16666666666666666) (* (* x x) x) x)
           (log (+ (- x (/ -0.5 x)) x)))))
      double code(double x) {
      	double tmp;
      	if (x <= -1.35) {
      		tmp = log((-0.5 / x));
      	} else if (x <= 1.05) {
      		tmp = fma(fma(0.075, (x * x), -0.16666666666666666), ((x * x) * x), x);
      	} else {
      		tmp = log(((x - (-0.5 / x)) + x));
      	}
      	return tmp;
      }
      
      function code(x)
      	tmp = 0.0
      	if (x <= -1.35)
      		tmp = log(Float64(-0.5 / x));
      	elseif (x <= 1.05)
      		tmp = fma(fma(0.075, Float64(x * x), -0.16666666666666666), Float64(Float64(x * x) * x), x);
      	else
      		tmp = log(Float64(Float64(x - Float64(-0.5 / x)) + x));
      	end
      	return tmp
      end
      
      code[x_] := If[LessEqual[x, -1.35], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.05], N[(N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 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 -1.35:\\
      \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\
      
      \mathbf{elif}\;x \leq 1.05:\\
      \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \left(x \cdot x\right) \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 < -1.3500000000000001

        1. Initial program 4.2%

          \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
        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-/.f6498.6

            \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
        5. Applied rewrites98.6%

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

        if -1.3500000000000001 < x < 1.05000000000000004

        1. Initial program 6.7%

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
        5. Applied rewrites100.0%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x \cdot x, 1\right) \cdot x} \]
        6. Step-by-step derivation
          1. Applied rewrites100.0%

            \[\leadsto \mathsf{fma}\left(\left(\mathsf{fma}\left(x \cdot x, 0.075, -0.16666666666666666\right) \cdot x\right) \cdot x, \color{blue}{x}, 1 \cdot x\right) \]
          2. Step-by-step derivation
            1. Applied rewrites100.0%

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

            if 1.05000000000000004 < x

            1. Initial program 49.2%

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

              \[\leadsto \log \left(x + \color{blue}{\left(x - \frac{-0.5}{x}\right)}\right) \]
          3. Recombined 3 regimes into one program.
          4. Final simplification99.6%

            \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.35:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.05:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \left(x \cdot x\right) \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x - \frac{-0.5}{x}\right) + x\right)\\ \end{array} \]
          5. Add Preprocessing

          Alternative 3: 99.4% accurate, 1.0× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.35:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.35:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \left(x \cdot x\right) \cdot x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(2 \cdot x\right)\\ \end{array} \end{array} \]
          (FPCore (x)
           :precision binary64
           (if (<= x -1.35)
             (log (/ -0.5 x))
             (if (<= x 1.35)
               (fma (fma 0.075 (* x x) -0.16666666666666666) (* (* x x) x) x)
               (log (* 2.0 x)))))
          double code(double x) {
          	double tmp;
          	if (x <= -1.35) {
          		tmp = log((-0.5 / x));
          	} else if (x <= 1.35) {
          		tmp = fma(fma(0.075, (x * x), -0.16666666666666666), ((x * x) * x), x);
          	} else {
          		tmp = log((2.0 * x));
          	}
          	return tmp;
          }
          
          function code(x)
          	tmp = 0.0
          	if (x <= -1.35)
          		tmp = log(Float64(-0.5 / x));
          	elseif (x <= 1.35)
          		tmp = fma(fma(0.075, Float64(x * x), -0.16666666666666666), Float64(Float64(x * x) * x), x);
          	else
          		tmp = log(Float64(2.0 * x));
          	end
          	return tmp
          end
          
          code[x_] := If[LessEqual[x, -1.35], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.35], N[(N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(2.0 * x), $MachinePrecision]], $MachinePrecision]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;x \leq -1.35:\\
          \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\
          
          \mathbf{elif}\;x \leq 1.35:\\
          \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \left(x \cdot x\right) \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 < -1.3500000000000001

            1. Initial program 4.2%

              \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
            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-/.f6498.6

                \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
            5. Applied rewrites98.6%

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

            if -1.3500000000000001 < x < 1.3500000000000001

            1. Initial program 6.7%

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
            5. Applied rewrites100.0%

              \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x \cdot x, 1\right) \cdot x} \]
            6. Step-by-step derivation
              1. Applied rewrites100.0%

                \[\leadsto \mathsf{fma}\left(\left(\mathsf{fma}\left(x \cdot x, 0.075, -0.16666666666666666\right) \cdot x\right) \cdot x, \color{blue}{x}, 1 \cdot x\right) \]
              2. Step-by-step derivation
                1. Applied rewrites100.0%

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

                if 1.3500000000000001 < x

                1. Initial program 49.2%

                  \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
                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-*.f6499.4

                    \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
                5. Applied rewrites99.4%

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

              Alternative 4: 75.5% 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 5.8%

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

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

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

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

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

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

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

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

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

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

                    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\frac{3}{40}, x \cdot x, \frac{-1}{6}\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
                  12. lower-*.f6467.9

                    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
                5. Applied rewrites67.9%

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

                  \[\leadsto 1 \cdot x \]
                7. Step-by-step derivation
                  1. Applied rewrites68.3%

                    \[\leadsto 1 \cdot x \]

                  if 1.25 < x

                  1. Initial program 49.2%

                    \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
                  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-*.f6499.4

                      \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
                  5. Applied rewrites99.4%

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

                Alternative 5: 58.4% 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 5.8%

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

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

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

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

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

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

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

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

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

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

                      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\frac{3}{40}, x \cdot x, \frac{-1}{6}\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
                    12. lower-*.f6467.9

                      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
                  5. Applied rewrites67.9%

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

                    \[\leadsto 1 \cdot x \]
                  7. Step-by-step derivation
                    1. Applied rewrites68.3%

                      \[\leadsto 1 \cdot x \]

                    if 1.6000000000000001 < x

                    1. Initial program 49.2%

                      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
                    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 rewrites31.6%

                        \[\leadsto \log \left(x + \color{blue}{1}\right) \]
                    5. Recombined 2 regimes into one program.
                    6. Final simplification59.6%

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

                    Alternative 6: 51.8% 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 16.2%

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

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

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

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

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

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

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

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

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

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

                        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\frac{3}{40}, x \cdot x, \frac{-1}{6}\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
                      12. lower-*.f6452.5

                        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), \color{blue}{x \cdot x}, 1\right) \cdot x \]
                    5. Applied rewrites52.5%

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

                      \[\leadsto 1 \cdot x \]
                    7. Step-by-step derivation
                      1. Applied rewrites53.3%

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

                      Developer Target 1: 29.3% 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 2024240 
                      (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)))))