Rust f64::asinh

Percentage Accurate: 29.1% → 99.8%
Time: 2.8s
Alternatives: 5
Speedup: 5.4×

Specification

?
\[\begin{array}{l} \\ \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))
double code(double x) {
	return copysign(log((fabs(x) + sqrt(((x * x) + 1.0)))), x);
}
public static double code(double x) {
	return Math.copySign(Math.log((Math.abs(x) + Math.sqrt(((x * x) + 1.0)))), x);
}
def code(x):
	return math.copysign(math.log((math.fabs(x) + math.sqrt(((x * x) + 1.0)))), x)
function code(x)
	return copysign(log(Float64(abs(x) + sqrt(Float64(Float64(x * x) + 1.0)))), x)
end
function tmp = code(x)
	tmp = sign(x) * abs(log((abs(x) + sqrt(((x * x) + 1.0)))));
end
code[x_] := N[With[{TMP1 = Abs[N[Log[N[(N[Abs[x], $MachinePrecision] + N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
\begin{array}{l}

\\
\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right)
\end{array}

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 5 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: 29.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))
double code(double x) {
	return copysign(log((fabs(x) + sqrt(((x * x) + 1.0)))), x);
}
public static double code(double x) {
	return Math.copySign(Math.log((Math.abs(x) + Math.sqrt(((x * x) + 1.0)))), x);
}
def code(x):
	return math.copysign(math.log((math.fabs(x) + math.sqrt(((x * x) + 1.0)))), x)
function code(x)
	return copysign(log(Float64(abs(x) + sqrt(Float64(Float64(x * x) + 1.0)))), x)
end
function tmp = code(x)
	tmp = sign(x) * abs(log((abs(x) + sqrt(((x * x) + 1.0)))));
end
code[x_] := N[With[{TMP1 = Abs[N[Log[N[(N[Abs[x], $MachinePrecision] + N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
\begin{array}{l}

\\
\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right)
\end{array}

Alternative 1: 99.8% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \mathsf{copysign}\left(\sinh^{-1} x, x\right) \end{array} \]
(FPCore (x) :precision binary64 (copysign (asinh x) x))
double code(double x) {
	return copysign(asinh(x), x);
}
def code(x):
	return math.copysign(math.asinh(x), x)
function code(x)
	return copysign(asinh(x), x)
end
function tmp = code(x)
	tmp = sign(x) * abs(asinh(x));
end
code[x_] := N[With[{TMP1 = Abs[N[ArcSinh[x], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
\begin{array}{l}

\\
\mathsf{copysign}\left(\sinh^{-1} x, x\right)
\end{array}
Derivation
  1. Initial program 29.1%

    \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
  2. Step-by-step derivation
    1. lift-log.f64N/A

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

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

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

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
    5. lift-*.f64N/A

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

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
    7. pow2N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2}} + 1}\right), x\right) \]
    8. +-commutativeN/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{1 + {x}^{2}}}\right), x\right) \]
    9. +-commutativeN/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2} + 1}}\right), x\right) \]
    10. pow2N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
    11. sqr-abs-revN/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
    12. asinh-def-revN/A

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
    13. rem-sqrt-square-revN/A

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
    14. pow2N/A

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
    15. sqrt-pow1N/A

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

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
    17. unpow1N/A

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
    18. lower-asinh.f6499.8

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
  3. Applied rewrites99.8%

    \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
  4. Add Preprocessing

Alternative 2: 75.8% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x + x\right), x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.25) (copysign x x) (copysign (log (+ x x)) x)))
double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = copysign(x, x);
	} else {
		tmp = copysign(log((x + x)), x);
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = Math.copySign(x, x);
	} else {
		tmp = Math.copySign(Math.log((x + x)), x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.25:
		tmp = math.copysign(x, x)
	else:
		tmp = math.copysign(math.log((x + x)), x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.25)
		tmp = copysign(x, x);
	else
		tmp = copysign(log(Float64(x + x)), x);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.25)
		tmp = sign(x) * abs(x);
	else
		tmp = sign(x) * abs(log((x + x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.25], N[With[{TMP1 = Abs[x], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], N[With[{TMP1 = Abs[N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.25:\\
\;\;\;\;\mathsf{copysign}\left(x, x\right)\\

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


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

    1. Initial program 22.1%

      \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
    2. Step-by-step derivation
      1. lift-log.f64N/A

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

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

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

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
      5. lift-*.f64N/A

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

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
      7. pow2N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2}} + 1}\right), x\right) \]
      8. +-commutativeN/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{1 + {x}^{2}}}\right), x\right) \]
      9. +-commutativeN/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2} + 1}}\right), x\right) \]
      10. pow2N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
      11. sqr-abs-revN/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
      12. asinh-def-revN/A

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
      13. rem-sqrt-square-revN/A

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
      14. pow2N/A

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
      15. sqrt-pow1N/A

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

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
      17. unpow1N/A

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
      18. lower-asinh.f6499.9

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
    3. Applied rewrites99.9%

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
    4. Taylor expanded in x around 0

      \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
    5. Step-by-step derivation
      1. unpow168.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      2. metadata-eval68.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      3. sqrt-pow168.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      4. pow268.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      5. rem-sqrt-square-rev68.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      6. asinh-def-rev68.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      7. sqr-abs-rev68.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      8. pow268.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      9. +-commutative68.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      10. +-commutative68.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      11. pow268.0

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
    6. Applied rewrites68.0%

      \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]

    if 1.25 < x

    1. Initial program 50.3%

      \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
    2. Taylor expanded in x around inf

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{x}\right), x\right) \]
    3. Step-by-step derivation
      1. Applied rewrites99.3%

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{x}\right), x\right) \]
      2. Step-by-step derivation
        1. lift-fabs.f64N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + x\right), x\right) \]
        2. lift-+.f64N/A

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + x\right)}, x\right) \]
        3. +-commutativeN/A

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x + \left|x\right|\right)}, x\right) \]
        4. rem-sqrt-square-revN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\sqrt{x \cdot x}}\right), x\right) \]
        5. pow2N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
        6. sqrt-pow1N/A

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

          \[\leadsto \mathsf{copysign}\left(\log \left(x + {x}^{\color{blue}{1}}\right), x\right) \]
        8. unpow1N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{x}\right), x\right) \]
        9. lower-+.f6499.3

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x + x\right)}, x\right) \]
      3. Applied rewrites99.3%

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

    Alternative 3: 58.9% accurate, 0.6× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \leq 1:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x - -1\right), x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x) 1.0)
       (copysign x x)
       (copysign (log (- x -1.0)) x)))
    double code(double x) {
    	double tmp;
    	if (copysign(log((fabs(x) + sqrt(((x * x) + 1.0)))), x) <= 1.0) {
    		tmp = copysign(x, x);
    	} else {
    		tmp = copysign(log((x - -1.0)), x);
    	}
    	return tmp;
    }
    
    public static double code(double x) {
    	double tmp;
    	if (Math.copySign(Math.log((Math.abs(x) + Math.sqrt(((x * x) + 1.0)))), x) <= 1.0) {
    		tmp = Math.copySign(x, x);
    	} else {
    		tmp = Math.copySign(Math.log((x - -1.0)), x);
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if math.copysign(math.log((math.fabs(x) + math.sqrt(((x * x) + 1.0)))), x) <= 1.0:
    		tmp = math.copysign(x, x)
    	else:
    		tmp = math.copysign(math.log((x - -1.0)), x)
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (copysign(log(Float64(abs(x) + sqrt(Float64(Float64(x * x) + 1.0)))), x) <= 1.0)
    		tmp = copysign(x, x);
    	else
    		tmp = copysign(log(Float64(x - -1.0)), x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if ((sign(x) * abs(log((abs(x) + sqrt(((x * x) + 1.0)))))) <= 1.0)
    		tmp = sign(x) * abs(x);
    	else
    		tmp = sign(x) * abs(log((x - -1.0)));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[LessEqual[N[With[{TMP1 = Abs[N[Log[N[(N[Abs[x], $MachinePrecision] + N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], 1.0], N[With[{TMP1 = Abs[x], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], N[With[{TMP1 = Abs[N[Log[N[(x - -1.0), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \leq 1:\\
    \;\;\;\;\mathsf{copysign}\left(x, x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(x - -1\right), x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (copysign.f64 (log.f64 (+.f64 (fabs.f64 x) (sqrt.f64 (+.f64 (*.f64 x x) #s(literal 1 binary64))))) x) < 1

      1. Initial program 22.1%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. lift-log.f64N/A

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

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

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

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
        5. lift-*.f64N/A

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

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
        7. pow2N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2}} + 1}\right), x\right) \]
        8. +-commutativeN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{1 + {x}^{2}}}\right), x\right) \]
        9. +-commutativeN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2} + 1}}\right), x\right) \]
        10. pow2N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
        11. sqr-abs-revN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
        12. asinh-def-revN/A

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
        13. rem-sqrt-square-revN/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
        14. pow2N/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
        15. sqrt-pow1N/A

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

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
        17. unpow1N/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
        18. lower-asinh.f6499.9

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
      3. Applied rewrites99.9%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
      4. Taylor expanded in x around 0

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
      5. Step-by-step derivation
        1. unpow168.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        2. metadata-eval68.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        3. sqrt-pow168.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        4. pow268.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        5. rem-sqrt-square-rev68.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        6. asinh-def-rev68.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        7. sqr-abs-rev68.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        8. pow268.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        9. +-commutative68.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        10. +-commutative68.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        11. pow268.0

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      6. Applied rewrites68.0%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]

      if 1 < (copysign.f64 (log.f64 (+.f64 (fabs.f64 x) (sqrt.f64 (+.f64 (*.f64 x x) #s(literal 1 binary64))))) x)

      1. Initial program 50.3%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Taylor expanded in x around inf

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{x}\right), x\right) \]
      3. Step-by-step derivation
        1. Applied rewrites99.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{x}\right), x\right) \]
        2. Step-by-step derivation
          1. lift-fabs.f64N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + x\right), x\right) \]
          2. lift-+.f64N/A

            \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + x\right)}, x\right) \]
          3. +-commutativeN/A

            \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x + \left|x\right|\right)}, x\right) \]
          4. rem-sqrt-square-revN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\sqrt{x \cdot x}}\right), x\right) \]
          5. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
          6. sqrt-pow1N/A

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

            \[\leadsto \mathsf{copysign}\left(\log \left(x + {x}^{\color{blue}{1}}\right), x\right) \]
          8. unpow1N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{x}\right), x\right) \]
          9. lower-+.f6499.3

            \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x + x\right)}, x\right) \]
        3. Applied rewrites99.3%

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x + x\right)}, x\right) \]
        4. Taylor expanded in x around -inf

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)}, x\right) \]
        5. Step-by-step derivation
          1. +-commutativeN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\color{blue}{\frac{-1}{2}}}{x}\right), x\right) \]
          2. unpow1N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\frac{-1}{2}}{x}\right), x\right) \]
          3. metadata-evalN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\frac{-1}{2}}{x}\right), x\right) \]
          4. sqrt-pow1N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\frac{-1}{2}}{x}\right), x\right) \]
          5. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\frac{-1}{2}}{x}\right), x\right) \]
          6. rem-sqrt-square-revN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\frac{-1}{2}}{x}\right), x\right) \]
          7. lower-/.f640.0

            \[\leadsto \mathsf{copysign}\left(\log \left(\frac{-0.5}{\color{blue}{x}}\right), x\right) \]
        6. Applied rewrites0.0%

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{-0.5}{x}\right)}, x\right) \]
        7. Taylor expanded in x around 0

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

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{1}\right), x\right) \]
          2. rem-sqrt-square-revN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x} + 1\right), x\right) \]
          3. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{{x}^{2}} + 1\right), x\right) \]
          4. sqrt-pow1N/A

            \[\leadsto \mathsf{copysign}\left(\log \left({x}^{\left(\frac{2}{2}\right)} + 1\right), x\right) \]
          5. metadata-evalN/A

            \[\leadsto \mathsf{copysign}\left(\log \left({x}^{1} + 1\right), x\right) \]
          6. unpow1N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(x + 1\right), x\right) \]
          7. metadata-evalN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(x + 1 \cdot \color{blue}{1}\right), x\right) \]
          8. fp-cancel-sign-sub-invN/A

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

            \[\leadsto \mathsf{copysign}\left(\log \left(x - -1 \cdot 1\right), x\right) \]
          10. metadata-evalN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(x - -1\right), x\right) \]
          11. lower--.f6431.5

            \[\leadsto \mathsf{copysign}\left(\log \left(x - \color{blue}{-1}\right), x\right) \]
        9. Applied rewrites31.5%

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x - -1\right)}, x\right) \]
      4. Recombined 2 regimes into one program.
      5. Add Preprocessing

      Alternative 4: 58.9% accurate, 0.6× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \leq 1:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log x, x\right)\\ \end{array} \end{array} \]
      (FPCore (x)
       :precision binary64
       (if (<= (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x) 1.0)
         (copysign x x)
         (copysign (log x) x)))
      double code(double x) {
      	double tmp;
      	if (copysign(log((fabs(x) + sqrt(((x * x) + 1.0)))), x) <= 1.0) {
      		tmp = copysign(x, x);
      	} else {
      		tmp = copysign(log(x), x);
      	}
      	return tmp;
      }
      
      public static double code(double x) {
      	double tmp;
      	if (Math.copySign(Math.log((Math.abs(x) + Math.sqrt(((x * x) + 1.0)))), x) <= 1.0) {
      		tmp = Math.copySign(x, x);
      	} else {
      		tmp = Math.copySign(Math.log(x), x);
      	}
      	return tmp;
      }
      
      def code(x):
      	tmp = 0
      	if math.copysign(math.log((math.fabs(x) + math.sqrt(((x * x) + 1.0)))), x) <= 1.0:
      		tmp = math.copysign(x, x)
      	else:
      		tmp = math.copysign(math.log(x), x)
      	return tmp
      
      function code(x)
      	tmp = 0.0
      	if (copysign(log(Float64(abs(x) + sqrt(Float64(Float64(x * x) + 1.0)))), x) <= 1.0)
      		tmp = copysign(x, x);
      	else
      		tmp = copysign(log(x), x);
      	end
      	return tmp
      end
      
      function tmp_2 = code(x)
      	tmp = 0.0;
      	if ((sign(x) * abs(log((abs(x) + sqrt(((x * x) + 1.0)))))) <= 1.0)
      		tmp = sign(x) * abs(x);
      	else
      		tmp = sign(x) * abs(log(x));
      	end
      	tmp_2 = tmp;
      end
      
      code[x_] := If[LessEqual[N[With[{TMP1 = Abs[N[Log[N[(N[Abs[x], $MachinePrecision] + N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], 1.0], N[With[{TMP1 = Abs[x], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], N[With[{TMP1 = Abs[N[Log[x], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \leq 1:\\
      \;\;\;\;\mathsf{copysign}\left(x, x\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{copysign}\left(\log x, x\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (copysign.f64 (log.f64 (+.f64 (fabs.f64 x) (sqrt.f64 (+.f64 (*.f64 x x) #s(literal 1 binary64))))) x) < 1

        1. Initial program 22.1%

          \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
        2. Step-by-step derivation
          1. lift-log.f64N/A

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

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

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

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
          5. lift-*.f64N/A

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

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
          7. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2}} + 1}\right), x\right) \]
          8. +-commutativeN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{1 + {x}^{2}}}\right), x\right) \]
          9. +-commutativeN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2} + 1}}\right), x\right) \]
          10. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
          11. sqr-abs-revN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
          12. asinh-def-revN/A

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
          13. rem-sqrt-square-revN/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
          14. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
          15. sqrt-pow1N/A

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

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
          17. unpow1N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
          18. lower-asinh.f6499.9

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
        3. Applied rewrites99.9%

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
        4. Taylor expanded in x around 0

          \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
        5. Step-by-step derivation
          1. unpow168.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          2. metadata-eval68.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          3. sqrt-pow168.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          4. pow268.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          5. rem-sqrt-square-rev68.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          6. asinh-def-rev68.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          7. sqr-abs-rev68.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          8. pow268.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          9. +-commutative68.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          10. +-commutative68.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          11. pow268.0

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        6. Applied rewrites68.0%

          \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]

        if 1 < (copysign.f64 (log.f64 (+.f64 (fabs.f64 x) (sqrt.f64 (+.f64 (*.f64 x x) #s(literal 1 binary64))))) x)

        1. Initial program 50.3%

          \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
        2. Taylor expanded in x around inf

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{x}, x\right) \]
        3. Step-by-step derivation
          1. Applied rewrites31.5%

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

        Alternative 5: 52.4% accurate, 5.4× speedup?

        \[\begin{array}{l} \\ \mathsf{copysign}\left(x, x\right) \end{array} \]
        (FPCore (x) :precision binary64 (copysign x x))
        double code(double x) {
        	return copysign(x, x);
        }
        
        public static double code(double x) {
        	return Math.copySign(x, x);
        }
        
        def code(x):
        	return math.copysign(x, x)
        
        function code(x)
        	return copysign(x, x)
        end
        
        function tmp = code(x)
        	tmp = sign(x) * abs(x);
        end
        
        code[x_] := N[With[{TMP1 = Abs[x], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \mathsf{copysign}\left(x, x\right)
        \end{array}
        
        Derivation
        1. Initial program 29.1%

          \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
        2. Step-by-step derivation
          1. lift-log.f64N/A

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

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

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

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
          5. lift-*.f64N/A

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

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
          7. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2}} + 1}\right), x\right) \]
          8. +-commutativeN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{1 + {x}^{2}}}\right), x\right) \]
          9. +-commutativeN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2} + 1}}\right), x\right) \]
          10. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
          11. sqr-abs-revN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
          12. asinh-def-revN/A

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
          13. rem-sqrt-square-revN/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
          14. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
          15. sqrt-pow1N/A

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

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
          17. unpow1N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
          18. lower-asinh.f6499.8

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
        3. Applied rewrites99.8%

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
        4. Taylor expanded in x around 0

          \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
        5. Step-by-step derivation
          1. unpow152.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          2. metadata-eval52.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          3. sqrt-pow152.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          4. pow252.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          5. rem-sqrt-square-rev52.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          6. asinh-def-rev52.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          7. sqr-abs-rev52.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          8. pow252.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          9. +-commutative52.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          10. +-commutative52.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          11. pow252.4

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        6. Applied rewrites52.4%

          \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
        7. Add Preprocessing

        Developer Target 1: 99.9% accurate, 0.4× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\left|x\right|}\\ \mathsf{copysign}\left(\mathsf{log1p}\left(\left|x\right| + \frac{\left|x\right|}{\mathsf{hypot}\left(1, t\_0\right) + t\_0}\right), x\right) \end{array} \end{array} \]
        (FPCore (x)
         :precision binary64
         (let* ((t_0 (/ 1.0 (fabs x))))
           (copysign (log1p (+ (fabs x) (/ (fabs x) (+ (hypot 1.0 t_0) t_0)))) x)))
        double code(double x) {
        	double t_0 = 1.0 / fabs(x);
        	return copysign(log1p((fabs(x) + (fabs(x) / (hypot(1.0, t_0) + t_0)))), x);
        }
        
        public static double code(double x) {
        	double t_0 = 1.0 / Math.abs(x);
        	return Math.copySign(Math.log1p((Math.abs(x) + (Math.abs(x) / (Math.hypot(1.0, t_0) + t_0)))), x);
        }
        
        def code(x):
        	t_0 = 1.0 / math.fabs(x)
        	return math.copysign(math.log1p((math.fabs(x) + (math.fabs(x) / (math.hypot(1.0, t_0) + t_0)))), x)
        
        function code(x)
        	t_0 = Float64(1.0 / abs(x))
        	return copysign(log1p(Float64(abs(x) + Float64(abs(x) / Float64(hypot(1.0, t_0) + t_0)))), x)
        end
        
        code[x_] := Block[{t$95$0 = N[(1.0 / N[Abs[x], $MachinePrecision]), $MachinePrecision]}, N[With[{TMP1 = Abs[N[Log[1 + N[(N[Abs[x], $MachinePrecision] + N[(N[Abs[x], $MachinePrecision] / N[(N[Sqrt[1.0 ^ 2 + t$95$0 ^ 2], $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_0 := \frac{1}{\left|x\right|}\\
        \mathsf{copysign}\left(\mathsf{log1p}\left(\left|x\right| + \frac{\left|x\right|}{\mathsf{hypot}\left(1, t\_0\right) + t\_0}\right), x\right)
        \end{array}
        \end{array}
        

        Reproduce

        ?
        herbie shell --seed 2025124 
        (FPCore (x)
          :name "Rust f64::asinh"
          :precision binary64
        
          :alt
          (! :herbie-platform c (let* ((ax (fabs x)) (ix (/ 1 ax))) (copysign (log1p (+ ax (/ ax (+ (hypot 1 ix) ix)))) x)))
        
          (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))