Hyperbolic arcsine

Percentage Accurate: 17.7% → 99.5%
Time: 9.7s
Alternatives: 7
Speedup: 7.2×

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 7 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: 17.7% 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: 99.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -10000:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 5000000:\\ \;\;\;\;\log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5}\right)\right) - \mathsf{log1p}\left(\left(\left(x + x\right) - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right) \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -10000.0)
   (log (/ -0.5 x))
   (if (<= x 5000000.0)
     (-
      (log (fma (* x x) x (pow (fma x x 1.0) 1.5)))
      (log1p (* (- (+ x x) (sqrt (fma x x 1.0))) x)))
     (log (+ x x)))))
double code(double x) {
	double tmp;
	if (x <= -10000.0) {
		tmp = log((-0.5 / x));
	} else if (x <= 5000000.0) {
		tmp = log(fma((x * x), x, pow(fma(x, x, 1.0), 1.5))) - log1p((((x + x) - sqrt(fma(x, x, 1.0))) * x));
	} else {
		tmp = log((x + x));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= -10000.0)
		tmp = log(Float64(-0.5 / x));
	elseif (x <= 5000000.0)
		tmp = Float64(log(fma(Float64(x * x), x, (fma(x, x, 1.0) ^ 1.5))) - log1p(Float64(Float64(Float64(x + x) - sqrt(fma(x, x, 1.0))) * x)));
	else
		tmp = log(Float64(x + x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -10000.0], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 5000000.0], N[(N[Log[N[(N[(x * x), $MachinePrecision] * x + N[Power[N[(x * x + 1.0), $MachinePrecision], 1.5], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[Log[1 + N[(N[(N[(x + x), $MachinePrecision] - N[Sqrt[N[(x * x + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -10000:\\
\;\;\;\;\log \left(\frac{-0.5}{x}\right)\\

\mathbf{elif}\;x \leq 5000000:\\
\;\;\;\;\log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5}\right)\right) - \mathsf{log1p}\left(\left(\left(x + x\right) - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right) \cdot x\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1e4

    1. Initial program 1.8%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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-/.f64100.0

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

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

    if -1e4 < x < 5e6

    1. Initial program 11.9%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-log.f64N/A

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

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

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

        \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
      5. lower--.f64N/A

        \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
    4. Applied rewrites98.3%

      \[\leadsto \color{blue}{\log \left({\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5} + {x}^{3}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right)} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \log \color{blue}{\left({\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}} + {x}^{3}\right)} - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right) \]
      2. +-commutativeN/A

        \[\leadsto \log \color{blue}{\left({x}^{3} + {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)} - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right) \]
      3. lift-pow.f64N/A

        \[\leadsto \log \left(\color{blue}{{x}^{3}} + {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right) \]
      4. unpow3N/A

        \[\leadsto \log \left(\color{blue}{\left(x \cdot x\right) \cdot x} + {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right) \]
      5. lower-fma.f64N/A

        \[\leadsto \log \color{blue}{\left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right)} - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right) \]
      6. lower-*.f6498.3

        \[\leadsto \log \left(\mathsf{fma}\left(\color{blue}{x \cdot x}, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right) \]
    6. Applied rewrites98.3%

      \[\leadsto \log \color{blue}{\left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5}\right)\right)} - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right) \]
    7. Step-by-step derivation
      1. lift-fma.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\color{blue}{x \cdot x + x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)}\right) \]
      2. lift-*.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(x \cdot x + \color{blue}{x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)}\right) \]
      3. distribute-lft-outN/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\color{blue}{x \cdot \left(x + \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)}\right) \]
      4. *-commutativeN/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(x + \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right) \cdot x}\right) \]
      5. lower-*.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(x + \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right) \cdot x}\right) \]
      6. lift--.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\left(x + \color{blue}{\left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)}\right) \cdot x\right) \]
      7. lift-sqrt.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\left(x + \left(x - \color{blue}{\sqrt{\mathsf{fma}\left(x, x, 1\right)}}\right)\right) \cdot x\right) \]
      8. lift-fma.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\left(x + \left(x - \sqrt{\color{blue}{x \cdot x + 1}}\right)\right) \cdot x\right) \]
      9. associate-+r-N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(\left(x + x\right) - \sqrt{x \cdot x + 1}\right)} \cdot x\right) \]
      10. lower--.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(\left(x + x\right) - \sqrt{x \cdot x + 1}\right)} \cdot x\right) \]
      11. lower-+.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\left(\color{blue}{\left(x + x\right)} - \sqrt{x \cdot x + 1}\right) \cdot x\right) \]
      12. lift-fma.f64N/A

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{\frac{3}{2}}\right)\right) - \mathsf{log1p}\left(\left(\left(x + x\right) - \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right) \cdot x\right) \]
      13. lift-sqrt.f6498.3

        \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5}\right)\right) - \mathsf{log1p}\left(\left(\left(x + x\right) - \color{blue}{\sqrt{\mathsf{fma}\left(x, x, 1\right)}}\right) \cdot x\right) \]
    8. Applied rewrites98.3%

      \[\leadsto \log \left(\mathsf{fma}\left(x \cdot x, x, {\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(\left(x + x\right) - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right) \cdot x}\right) \]

    if 5e6 < x

    1. Initial program 49.6%

      \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
    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-*.f64100.0

        \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
    5. Applied rewrites100.0%

      \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
    6. Step-by-step derivation
      1. Applied rewrites100.0%

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

    Alternative 2: 99.5% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + \left(x - \frac{-0.5}{x}\right)\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.3)
       (log (/ -0.5 x))
       (if (<= x 1.0)
         (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
         (log (+ x (- x (/ -0.5 x)))))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = log((-0.5 / x));
    	} else if (x <= 1.0) {
    		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
    	} else {
    		tmp = log((x + (x - (-0.5 / x))));
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.3)
    		tmp = log(Float64(-0.5 / x));
    	elseif (x <= 1.0)
    		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
    	else
    		tmp = log(Float64(x + Float64(x - Float64(-0.5 / x))));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[x, -1.3], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.0], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x + N[(x - N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.3:\\
    \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\
    
    \mathbf{elif}\;x \leq 1:\\
    \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\log \left(x + \left(x - \frac{-0.5}{x}\right)\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.30000000000000004

      1. Initial program 4.9%

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

        \[\leadsto \log \color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)} \]
      4. Step-by-step derivation
        1. lower-/.f6497.8

          \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
      5. Applied rewrites97.8%

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

      if -1.30000000000000004 < x < 1

      1. Initial program 9.5%

        \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-log.f64N/A

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

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

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

          \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
        5. lower--.f64N/A

          \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
      4. Applied rewrites98.4%

        \[\leadsto \color{blue}{\log \left({\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5} + {x}^{3}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right)} \]
      5. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
        13. lower-*.f6499.4

          \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
      7. Applied rewrites99.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
      8. Step-by-step derivation
        1. Applied rewrites99.4%

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

        if 1 < x

        1. Initial program 51.6%

          \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
        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-lft-inN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{-0.5}{x}}\right)\right) \]
        5. Applied rewrites99.1%

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

      Alternative 3: 99.4% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\ \mathbf{elif}\;x \leq 1.3:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
      (FPCore (x)
       :precision binary64
       (if (<= x -1.3)
         (log (/ -0.5 x))
         (if (<= x 1.3)
           (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
           (log (+ x x)))))
      double code(double x) {
      	double tmp;
      	if (x <= -1.3) {
      		tmp = log((-0.5 / x));
      	} else if (x <= 1.3) {
      		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
      	} else {
      		tmp = log((x + x));
      	}
      	return tmp;
      }
      
      function code(x)
      	tmp = 0.0
      	if (x <= -1.3)
      		tmp = log(Float64(-0.5 / x));
      	elseif (x <= 1.3)
      		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
      	else
      		tmp = log(Float64(x + x));
      	end
      	return tmp
      end
      
      code[x_] := If[LessEqual[x, -1.3], N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 1.3], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;x \leq -1.3:\\
      \;\;\;\;\log \left(\frac{-0.5}{x}\right)\\
      
      \mathbf{elif}\;x \leq 1.3:\\
      \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\log \left(x + x\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if x < -1.30000000000000004

        1. Initial program 4.9%

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

          \[\leadsto \log \color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)} \]
        4. Step-by-step derivation
          1. lower-/.f6497.8

            \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x}\right)} \]
        5. Applied rewrites97.8%

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

        if -1.30000000000000004 < x < 1.30000000000000004

        1. Initial program 9.5%

          \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-log.f64N/A

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

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

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

            \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
          5. lower--.f64N/A

            \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
        4. Applied rewrites98.4%

          \[\leadsto \color{blue}{\log \left({\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5} + {x}^{3}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right)} \]
        5. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
          13. lower-*.f6499.4

            \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
        7. Applied rewrites99.4%

          \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
        8. Step-by-step derivation
          1. Applied rewrites99.4%

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

          if 1.30000000000000004 < x

          1. Initial program 51.6%

            \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
          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-*.f6498.0

              \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
          5. Applied rewrites98.0%

            \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
          6. Step-by-step derivation
            1. Applied rewrites98.0%

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

          Alternative 4: 75.2% accurate, 1.1× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.3:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + x\right)\\ \end{array} \end{array} \]
          (FPCore (x)
           :precision binary64
           (if (<= x 1.3)
             (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
             (log (+ x x))))
          double code(double x) {
          	double tmp;
          	if (x <= 1.3) {
          		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
          	} else {
          		tmp = log((x + x));
          	}
          	return tmp;
          }
          
          function code(x)
          	tmp = 0.0
          	if (x <= 1.3)
          		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
          	else
          		tmp = log(Float64(x + x));
          	end
          	return tmp
          end
          
          code[x_] := If[LessEqual[x, 1.3], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;x \leq 1.3:\\
          \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\
          
          \mathbf{else}:\\
          \;\;\;\;\log \left(x + x\right)\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if x < 1.30000000000000004

            1. Initial program 8.2%

              \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
            2. Add Preprocessing
            3. Step-by-step derivation
              1. lift-log.f64N/A

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

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

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

                \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
              5. lower--.f64N/A

                \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
            4. Applied rewrites71.1%

              \[\leadsto \color{blue}{\log \left({\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5} + {x}^{3}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right)} \]
            5. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

                \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
              13. lower-*.f6471.7

                \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
            7. Applied rewrites71.7%

              \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
            8. Step-by-step derivation
              1. Applied rewrites71.7%

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

              if 1.30000000000000004 < x

              1. Initial program 51.6%

                \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
              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-*.f6498.0

                  \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
              5. Applied rewrites98.0%

                \[\leadsto \log \color{blue}{\left(2 \cdot x\right)} \]
              6. Step-by-step derivation
                1. Applied rewrites98.0%

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

              Alternative 5: 58.4% accurate, 1.1× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.52:\\ \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(1 + x\right)\\ \end{array} \end{array} \]
              (FPCore (x)
               :precision binary64
               (if (<= x 1.52)
                 (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x)
                 (log (+ 1.0 x))))
              double code(double x) {
              	double tmp;
              	if (x <= 1.52) {
              		tmp = fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
              	} else {
              		tmp = log((1.0 + x));
              	}
              	return tmp;
              }
              
              function code(x)
              	tmp = 0.0
              	if (x <= 1.52)
              		tmp = fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x);
              	else
              		tmp = log(Float64(1.0 + x));
              	end
              	return tmp
              end
              
              code[x_] := If[LessEqual[x, 1.52], N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision], N[Log[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              \mathbf{if}\;x \leq 1.52:\\
              \;\;\;\;\mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)\\
              
              \mathbf{else}:\\
              \;\;\;\;\log \left(1 + x\right)\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if x < 1.52

                1. Initial program 8.2%

                  \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
                2. Add Preprocessing
                3. Step-by-step derivation
                  1. lift-log.f64N/A

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

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

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

                    \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
                  5. lower--.f64N/A

                    \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
                4. Applied rewrites71.1%

                  \[\leadsto \color{blue}{\log \left({\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5} + {x}^{3}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right)} \]
                5. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

                    \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
                  13. lower-*.f6471.7

                    \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
                7. Applied rewrites71.7%

                  \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
                8. Step-by-step derivation
                  1. Applied rewrites71.7%

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

                  if 1.52 < x

                  1. Initial program 51.6%

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

                    \[\leadsto \log \color{blue}{\left(1 + x\right)} \]
                  4. Step-by-step derivation
                    1. lower-+.f6431.0

                      \[\leadsto \log \color{blue}{\left(1 + x\right)} \]
                  5. Applied rewrites31.0%

                    \[\leadsto \log \color{blue}{\left(1 + x\right)} \]
                9. Recombined 2 regimes into one program.
                10. Add Preprocessing

                Alternative 6: 51.6% accurate, 4.4× speedup?

                \[\begin{array}{l} \\ \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right) \end{array} \]
                (FPCore (x)
                 :precision binary64
                 (fma (* (* x x) x) (fma 0.075 (* x x) -0.16666666666666666) x))
                double code(double x) {
                	return fma(((x * x) * x), fma(0.075, (x * x), -0.16666666666666666), x);
                }
                
                function code(x)
                	return fma(Float64(Float64(x * x) * x), fma(0.075, Float64(x * x), -0.16666666666666666), x)
                end
                
                code[x_] := N[(N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision] * N[(0.075 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] + x), $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                \mathsf{fma}\left(\left(x \cdot x\right) \cdot x, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)
                \end{array}
                
                Derivation
                1. Initial program 17.0%

                  \[\log \left(x + \sqrt{x \cdot x + 1}\right) \]
                2. Add Preprocessing
                3. Step-by-step derivation
                  1. lift-log.f64N/A

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

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

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

                    \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
                  5. lower--.f64N/A

                    \[\leadsto \color{blue}{\log \left({x}^{3} + {\left(\sqrt{x \cdot x + 1}\right)}^{3}\right) - \log \left(x \cdot x + \left(\sqrt{x \cdot x + 1} \cdot \sqrt{x \cdot x + 1} - x \cdot \sqrt{x \cdot x + 1}\right)\right)} \]
                4. Applied rewrites63.7%

                  \[\leadsto \color{blue}{\log \left({\left(\mathsf{fma}\left(x, x, 1\right)\right)}^{1.5} + {x}^{3}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(x, x, x \cdot \left(x - \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right)\right)\right)} \]
                5. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

                    \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(\frac{3}{40}, \color{blue}{x \cdot x}, \frac{-1}{6}\right), x\right) \]
                  13. lower-*.f6457.9

                    \[\leadsto \mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, \color{blue}{x \cdot x}, -0.16666666666666666\right), x\right) \]
                7. Applied rewrites57.9%

                  \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, \mathsf{fma}\left(0.075, x \cdot x, -0.16666666666666666\right), x\right)} \]
                8. Step-by-step derivation
                  1. Applied rewrites57.9%

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

                  Alternative 7: 50.1% accurate, 7.2× speedup?

                  \[\begin{array}{l} \\ \mathsf{fma}\left(-0.16666666666666666 \cdot \left(x \cdot x\right), x, x\right) \end{array} \]
                  (FPCore (x) :precision binary64 (fma (* -0.16666666666666666 (* x x)) x x))
                  double code(double x) {
                  	return fma((-0.16666666666666666 * (x * x)), x, x);
                  }
                  
                  function code(x)
                  	return fma(Float64(-0.16666666666666666 * Float64(x * x)), x, x)
                  end
                  
                  code[x_] := N[(N[(-0.16666666666666666 * N[(x * x), $MachinePrecision]), $MachinePrecision] * x + x), $MachinePrecision]
                  
                  \begin{array}{l}
                  
                  \\
                  \mathsf{fma}\left(-0.16666666666666666 \cdot \left(x \cdot x\right), x, x\right)
                  \end{array}
                  
                  Derivation
                  1. Initial program 17.0%

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

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

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

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

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

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

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

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

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

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

                      \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(2 + 1\right)}}, \frac{-1}{6}, x\right) \]
                    10. metadata-eval56.6

                      \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{3}}, -0.16666666666666666, x\right) \]
                  5. Applied rewrites56.6%

                    \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{3}, -0.16666666666666666, x\right)} \]
                  6. Step-by-step derivation
                    1. Applied rewrites56.6%

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

                    Developer Target 1: 30.2% 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 2024307 
                    (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)))))