Rust f64::asinh

Percentage Accurate: 29.8% → 99.4%
Time: 10.0s
Alternatives: 9
Speedup: 4.0×

Specification

?
\[\begin{array}{l} \\ \sinh^{-1} x \end{array} \]
(FPCore (x) :precision binary64 (asinh x))
double code(double x) {
	return asinh(x);
}
def code(x):
	return math.asinh(x)
function code(x)
	return asinh(x)
end
function tmp = code(x)
	tmp = asinh(x);
end
code[x_] := N[ArcSinh[x], $MachinePrecision]
\begin{array}{l}

\\
\sinh^{-1} x
\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 9 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: 29.8% 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: 99.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right)\\ \mathbf{if}\;t\_0 \leq -10:\\ \;\;\;\;\mathsf{copysign}\left(-\log \left(\mathsf{hypot}\left(1, x\right) - x\right), x\right)\\ \mathbf{elif}\;t\_0 \leq 10^{-10}:\\ \;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x)))
   (if (<= t_0 -10.0)
     (copysign (- (log (- (hypot 1.0 x) x))) x)
     (if (<= t_0 1e-10)
       (copysign
        (* x (+ 1.0 (* (pow x 2.0) (- (* (* x x) 0.075) 0.16666666666666666))))
        x)
       (copysign (log (+ x (hypot 1.0 x))) x)))))
double code(double x) {
	double t_0 = copysign(log((fabs(x) + sqrt(((x * x) + 1.0)))), x);
	double tmp;
	if (t_0 <= -10.0) {
		tmp = copysign(-log((hypot(1.0, x) - x)), x);
	} else if (t_0 <= 1e-10) {
		tmp = copysign((x * (1.0 + (pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x);
	} else {
		tmp = copysign(log((x + hypot(1.0, x))), x);
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = Math.copySign(Math.log((Math.abs(x) + Math.sqrt(((x * x) + 1.0)))), x);
	double tmp;
	if (t_0 <= -10.0) {
		tmp = Math.copySign(-Math.log((Math.hypot(1.0, x) - x)), x);
	} else if (t_0 <= 1e-10) {
		tmp = Math.copySign((x * (1.0 + (Math.pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x);
	} else {
		tmp = Math.copySign(Math.log((x + Math.hypot(1.0, x))), x);
	}
	return tmp;
}
def code(x):
	t_0 = math.copysign(math.log((math.fabs(x) + math.sqrt(((x * x) + 1.0)))), x)
	tmp = 0
	if t_0 <= -10.0:
		tmp = math.copysign(-math.log((math.hypot(1.0, x) - x)), x)
	elif t_0 <= 1e-10:
		tmp = math.copysign((x * (1.0 + (math.pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x)
	else:
		tmp = math.copysign(math.log((x + math.hypot(1.0, x))), x)
	return tmp
function code(x)
	t_0 = copysign(log(Float64(abs(x) + sqrt(Float64(Float64(x * x) + 1.0)))), x)
	tmp = 0.0
	if (t_0 <= -10.0)
		tmp = copysign(Float64(-log(Float64(hypot(1.0, x) - x))), x);
	elseif (t_0 <= 1e-10)
		tmp = copysign(Float64(x * Float64(1.0 + Float64((x ^ 2.0) * Float64(Float64(Float64(x * x) * 0.075) - 0.16666666666666666)))), x);
	else
		tmp = copysign(log(Float64(x + hypot(1.0, x))), x);
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = sign(x) * abs(log((abs(x) + sqrt(((x * x) + 1.0)))));
	tmp = 0.0;
	if (t_0 <= -10.0)
		tmp = sign(x) * abs(-log((hypot(1.0, x) - x)));
	elseif (t_0 <= 1e-10)
		tmp = sign(x) * abs((x * (1.0 + ((x ^ 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))));
	else
		tmp = sign(x) * abs(log((x + hypot(1.0, x))));
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = 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]}, If[LessEqual[t$95$0, -10.0], N[With[{TMP1 = Abs[(-N[Log[N[(N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision] - x), $MachinePrecision]], $MachinePrecision])], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], If[LessEqual[t$95$0, 1e-10], N[With[{TMP1 = Abs[N[(x * N[(1.0 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(N[(x * x), $MachinePrecision] * 0.075), $MachinePrecision] - 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], N[With[{TMP1 = Abs[N[Log[N[(x + N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right)\\
\mathbf{if}\;t\_0 \leq -10:\\
\;\;\;\;\mathsf{copysign}\left(-\log \left(\mathsf{hypot}\left(1, x\right) - x\right), x\right)\\

\mathbf{elif}\;t\_0 \leq 10^{-10}:\\
\;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (copysign.f64 (log.f64 (+.f64 (fabs.f64 x) (sqrt.f64 (+.f64 (*.f64 x x) #s(literal 1 binary64))))) x) < -10

    1. Initial program 54.8%

      \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
    2. Step-by-step derivation
      1. fma-define54.8%

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
    3. Simplified54.8%

      \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. fma-undefine54.8%

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
      2. +-commutative54.8%

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{1 + x \cdot x}}\right), x\right) \]
      3. hypot-1-def100.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      4. flip-+1.7%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{\left|x\right| \cdot \left|x\right| - \mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right)}, x\right) \]
      5. div-sub1.7%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{\left|x\right| \cdot \left|x\right|}{\left|x\right| - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right)}, x\right) \]
      6. pow21.7%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\color{blue}{{\left(\left|x\right|\right)}^{2}}}{\left|x\right| - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. add-sqr-sqrt0.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{\left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|\right)}^{2}}{\left|x\right| - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      8. fabs-sqr0.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)}}^{2}}{\left|x\right| - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      9. add-sqr-sqrt1.7%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{\color{blue}{x}}^{2}}{\left|x\right| - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      10. add-sqr-sqrt0.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      11. fabs-sqr0.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{\color{blue}{\sqrt{x} \cdot \sqrt{x}} - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      12. add-sqr-sqrt0.6%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{\color{blue}{x} - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{hypot}\left(1, x\right) \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      13. hypot-1-def0.6%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\color{blue}{\sqrt{1 + x \cdot x}} \cdot \mathsf{hypot}\left(1, x\right)}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      14. hypot-1-def0.6%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\sqrt{1 + x \cdot x} \cdot \color{blue}{\sqrt{1 + x \cdot x}}}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      15. add-sqr-sqrt0.6%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\color{blue}{1 + x \cdot x}}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      16. +-commutative0.6%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\color{blue}{x \cdot x + 1}}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      17. fma-undefine0.6%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}{\left|x\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      18. add-sqr-sqrt0.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{fma}\left(x, x, 1\right)}{\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      19. fabs-sqr0.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{fma}\left(x, x, 1\right)}{\color{blue}{\sqrt{x} \cdot \sqrt{x}} - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      20. add-sqr-sqrt3.3%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{fma}\left(x, x, 1\right)}{\color{blue}{x} - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
    6. Applied egg-rr3.3%

      \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{{x}^{2}}{x - \mathsf{hypot}\left(1, x\right)} - \frac{\mathsf{fma}\left(x, x, 1\right)}{x - \mathsf{hypot}\left(1, x\right)}\right)}, x\right) \]
    7. Step-by-step derivation
      1. div-sub4.9%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{{x}^{2} - \mathsf{fma}\left(x, x, 1\right)}{x - \mathsf{hypot}\left(1, x\right)}\right)}, x\right) \]
      2. fma-undefine4.9%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2} - \color{blue}{\left(x \cdot x + 1\right)}}{x - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      3. unpow24.9%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{{x}^{2} - \left(\color{blue}{{x}^{2}} + 1\right)}{x - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      4. associate--r+53.3%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\color{blue}{\left({x}^{2} - {x}^{2}\right) - 1}}{x - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      5. +-inverses100.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\color{blue}{0} - 1}{x - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      6. metadata-eval100.0%

        \[\leadsto \mathsf{copysign}\left(\log \left(\frac{\color{blue}{-1}}{x - \mathsf{hypot}\left(1, x\right)}\right), x\right) \]
    8. Simplified100.0%

      \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{-1}{x - \mathsf{hypot}\left(1, x\right)}\right)}, x\right) \]
    9. Taylor expanded in x around 0 54.8%

      \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\frac{-1}{x - \sqrt{1 + {x}^{2}}}\right), x\right)} \]
    10. Step-by-step derivation
      1. Simplified100.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(-\log \left(\mathsf{hypot}\left(1, x\right) - x\right), x\right)} \]

      if -10 < (copysign.f64 (log.f64 (+.f64 (fabs.f64 x) (sqrt.f64 (+.f64 (*.f64 x x) #s(literal 1 binary64))))) x) < 1.00000000000000004e-10

      1. Initial program 6.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow26.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around 0 100.0%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot {x}^{2} - 0.16666666666666666\right)\right)}, x\right) \]
      9. Step-by-step derivation
        1. unpow2100.0%

          \[\leadsto \mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot \color{blue}{\left(x \cdot x\right)} - 0.16666666666666666\right)\right), x\right) \]
      10. Applied egg-rr100.0%

        \[\leadsto \mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot \color{blue}{\left(x \cdot x\right)} - 0.16666666666666666\right)\right), x\right) \]

      if 1.00000000000000004e-10 < (copysign.f64 (log.f64 (+.f64 (fabs.f64 x) (sqrt.f64 (+.f64 (*.f64 x x) #s(literal 1 binary64))))) x)

      1. Initial program 49.0%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified49.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 49.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow249.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine100.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified100.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
    11. Recombined 3 regimes into one program.
    12. Final simplification100.0%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \leq -10:\\ \;\;\;\;\mathsf{copysign}\left(-\log \left(\mathsf{hypot}\left(1, x\right) - x\right), x\right)\\ \mathbf{elif}\;\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \leq 10^{-10}:\\ \;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)\\ \end{array} \]
    13. Add Preprocessing

    Alternative 2: 99.7% accurate, 1.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.35:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\ \mathbf{elif}\;x \leq 0.0082:\\ \;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.35)
       (copysign (log (/ -0.5 x)) x)
       (if (<= x 0.0082)
         (copysign
          (* x (+ 1.0 (* (pow x 2.0) (- (* (* x x) 0.075) 0.16666666666666666))))
          x)
         (copysign (log (+ x (hypot 1.0 x))) x))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.35) {
    		tmp = copysign(log((-0.5 / x)), x);
    	} else if (x <= 0.0082) {
    		tmp = copysign((x * (1.0 + (pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x);
    	} else {
    		tmp = copysign(log((x + hypot(1.0, x))), x);
    	}
    	return tmp;
    }
    
    public static double code(double x) {
    	double tmp;
    	if (x <= -1.35) {
    		tmp = Math.copySign(Math.log((-0.5 / x)), x);
    	} else if (x <= 0.0082) {
    		tmp = Math.copySign((x * (1.0 + (Math.pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x);
    	} else {
    		tmp = Math.copySign(Math.log((x + Math.hypot(1.0, x))), x);
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if x <= -1.35:
    		tmp = math.copysign(math.log((-0.5 / x)), x)
    	elif x <= 0.0082:
    		tmp = math.copysign((x * (1.0 + (math.pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x)
    	else:
    		tmp = math.copysign(math.log((x + math.hypot(1.0, x))), x)
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.35)
    		tmp = copysign(log(Float64(-0.5 / x)), x);
    	elseif (x <= 0.0082)
    		tmp = copysign(Float64(x * Float64(1.0 + Float64((x ^ 2.0) * Float64(Float64(Float64(x * x) * 0.075) - 0.16666666666666666)))), x);
    	else
    		tmp = copysign(log(Float64(x + hypot(1.0, x))), x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if (x <= -1.35)
    		tmp = sign(x) * abs(log((-0.5 / x)));
    	elseif (x <= 0.0082)
    		tmp = sign(x) * abs((x * (1.0 + ((x ^ 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))));
    	else
    		tmp = sign(x) * abs(log((x + hypot(1.0, x))));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[LessEqual[x, -1.35], N[With[{TMP1 = Abs[N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], If[LessEqual[x, 0.0082], N[With[{TMP1 = Abs[N[(x * N[(1.0 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(N[(x * x), $MachinePrecision] * 0.075), $MachinePrecision] - 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], N[With[{TMP1 = Abs[N[Log[N[(x + N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.35:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\
    
    \mathbf{elif}\;x \leq 0.0082:\\
    \;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.3500000000000001

      1. Initial program 54.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define54.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt0.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr0.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow24.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified4.7%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around -inf 99.5%

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

      if -1.3500000000000001 < x < 0.00820000000000000069

      1. Initial program 6.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow26.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around 0 100.0%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot {x}^{2} - 0.16666666666666666\right)\right)}, x\right) \]
      9. Step-by-step derivation
        1. unpow2100.0%

          \[\leadsto \mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot \color{blue}{\left(x \cdot x\right)} - 0.16666666666666666\right)\right), x\right) \]
      10. Applied egg-rr100.0%

        \[\leadsto \mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot \color{blue}{\left(x \cdot x\right)} - 0.16666666666666666\right)\right), x\right) \]

      if 0.00820000000000000069 < x

      1. Initial program 49.0%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified49.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 49.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow249.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine100.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified100.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
    3. Recombined 3 regimes into one program.
    4. Final simplification99.9%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.35:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\ \mathbf{elif}\;x \leq 0.0082:\\ \;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 3: 99.5% accurate, 1.8× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.35:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.35)
       (copysign (log (/ -0.5 x)) x)
       (if (<= x 1.32)
         (copysign
          (* x (+ 1.0 (* (pow x 2.0) (- (* (* x x) 0.075) 0.16666666666666666))))
          x)
         (copysign (log (* x 2.0)) x))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.35) {
    		tmp = copysign(log((-0.5 / x)), x);
    	} else if (x <= 1.32) {
    		tmp = copysign((x * (1.0 + (pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x);
    	} else {
    		tmp = copysign(log((x * 2.0)), x);
    	}
    	return tmp;
    }
    
    public static double code(double x) {
    	double tmp;
    	if (x <= -1.35) {
    		tmp = Math.copySign(Math.log((-0.5 / x)), x);
    	} else if (x <= 1.32) {
    		tmp = Math.copySign((x * (1.0 + (Math.pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x);
    	} else {
    		tmp = Math.copySign(Math.log((x * 2.0)), x);
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if x <= -1.35:
    		tmp = math.copysign(math.log((-0.5 / x)), x)
    	elif x <= 1.32:
    		tmp = math.copysign((x * (1.0 + (math.pow(x, 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))), x)
    	else:
    		tmp = math.copysign(math.log((x * 2.0)), x)
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.35)
    		tmp = copysign(log(Float64(-0.5 / x)), x);
    	elseif (x <= 1.32)
    		tmp = copysign(Float64(x * Float64(1.0 + Float64((x ^ 2.0) * Float64(Float64(Float64(x * x) * 0.075) - 0.16666666666666666)))), x);
    	else
    		tmp = copysign(log(Float64(x * 2.0)), x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if (x <= -1.35)
    		tmp = sign(x) * abs(log((-0.5 / x)));
    	elseif (x <= 1.32)
    		tmp = sign(x) * abs((x * (1.0 + ((x ^ 2.0) * (((x * x) * 0.075) - 0.16666666666666666)))));
    	else
    		tmp = sign(x) * abs(log((x * 2.0)));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[LessEqual[x, -1.35], N[With[{TMP1 = Abs[N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], If[LessEqual[x, 1.32], N[With[{TMP1 = Abs[N[(x * N[(1.0 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(N[(x * x), $MachinePrecision] * 0.075), $MachinePrecision] - 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], N[With[{TMP1 = Abs[N[Log[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.35:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\
    
    \mathbf{elif}\;x \leq 1.32:\\
    \;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.3500000000000001

      1. Initial program 54.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define54.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt0.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr0.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow24.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified4.7%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around -inf 99.5%

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

      if -1.3500000000000001 < x < 1.32000000000000006

      1. Initial program 6.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow26.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around 0 100.0%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot {x}^{2} - 0.16666666666666666\right)\right)}, x\right) \]
      9. Step-by-step derivation
        1. unpow2100.0%

          \[\leadsto \mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot \color{blue}{\left(x \cdot x\right)} - 0.16666666666666666\right)\right), x\right) \]
      10. Applied egg-rr100.0%

        \[\leadsto \mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(0.075 \cdot \color{blue}{\left(x \cdot x\right)} - 0.16666666666666666\right)\right), x\right) \]

      if 1.32000000000000006 < x

      1. Initial program 49.0%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified49.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 98.7%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x \cdot \left(1 + \frac{\left|x\right|}{x}\right)\right)}, x\right) \]
      6. Step-by-step derivation
        1. +-commutative98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \color{blue}{\left(\frac{\left|x\right|}{x} + 1\right)}\right), x\right) \]
        2. rem-square-sqrt98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|}{x} + 1\right)\right), x\right) \]
        3. fabs-sqr98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\color{blue}{\sqrt{x} \cdot \sqrt{x}}}{x} + 1\right)\right), x\right) \]
        4. rem-square-sqrt98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\color{blue}{x}}{x} + 1\right)\right), x\right) \]
        5. *-inverses98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\color{blue}{1} + 1\right)\right), x\right) \]
        6. metadata-eval98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \color{blue}{2}\right), x\right) \]
      7. Simplified98.7%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x \cdot 2\right)}, x\right) \]
    3. Recombined 3 regimes into one program.
    4. Final simplification99.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.35:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\ \mathbf{elif}\;x \leq 1.32:\\ \;\;\;\;\mathsf{copysign}\left(x \cdot \left(1 + {x}^{2} \cdot \left(\left(x \cdot x\right) \cdot 0.075 - 0.16666666666666666\right)\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 4: 99.4% accurate, 1.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;\mathsf{copysign}\left(x + -0.16666666666666666 \cdot {x}^{3}, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.3)
       (copysign (log (/ -0.5 x)) x)
       (if (<= x 1.25)
         (copysign (+ x (* -0.16666666666666666 (pow x 3.0))) x)
         (copysign (log (* x 2.0)) x))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = copysign(log((-0.5 / x)), x);
    	} else if (x <= 1.25) {
    		tmp = copysign((x + (-0.16666666666666666 * pow(x, 3.0))), x);
    	} else {
    		tmp = copysign(log((x * 2.0)), x);
    	}
    	return tmp;
    }
    
    public static double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = Math.copySign(Math.log((-0.5 / x)), x);
    	} else if (x <= 1.25) {
    		tmp = Math.copySign((x + (-0.16666666666666666 * Math.pow(x, 3.0))), x);
    	} else {
    		tmp = Math.copySign(Math.log((x * 2.0)), x);
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if x <= -1.3:
    		tmp = math.copysign(math.log((-0.5 / x)), x)
    	elif x <= 1.25:
    		tmp = math.copysign((x + (-0.16666666666666666 * math.pow(x, 3.0))), x)
    	else:
    		tmp = math.copysign(math.log((x * 2.0)), x)
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.3)
    		tmp = copysign(log(Float64(-0.5 / x)), x);
    	elseif (x <= 1.25)
    		tmp = copysign(Float64(x + Float64(-0.16666666666666666 * (x ^ 3.0))), x);
    	else
    		tmp = copysign(log(Float64(x * 2.0)), x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if (x <= -1.3)
    		tmp = sign(x) * abs(log((-0.5 / x)));
    	elseif (x <= 1.25)
    		tmp = sign(x) * abs((x + (-0.16666666666666666 * (x ^ 3.0))));
    	else
    		tmp = sign(x) * abs(log((x * 2.0)));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[LessEqual[x, -1.3], N[With[{TMP1 = Abs[N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], If[LessEqual[x, 1.25], N[With[{TMP1 = Abs[N[(x + N[(-0.16666666666666666 * N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], N[With[{TMP1 = Abs[N[Log[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.3:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\
    
    \mathbf{elif}\;x \leq 1.25:\\
    \;\;\;\;\mathsf{copysign}\left(x + -0.16666666666666666 \cdot {x}^{3}, x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.30000000000000004

      1. Initial program 54.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define54.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt0.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr0.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow24.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified4.7%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around -inf 99.5%

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

      if -1.30000000000000004 < x < 1.25

      1. Initial program 6.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow26.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around 0 99.9%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x \cdot \left(1 + -0.16666666666666666 \cdot {x}^{2}\right)}, x\right) \]
      9. Step-by-step derivation
        1. distribute-rgt-in99.9%

          \[\leadsto \mathsf{copysign}\left(\color{blue}{1 \cdot x + \left(-0.16666666666666666 \cdot {x}^{2}\right) \cdot x}, x\right) \]
        2. *-lft-identity99.9%

          \[\leadsto \mathsf{copysign}\left(\color{blue}{x} + \left(-0.16666666666666666 \cdot {x}^{2}\right) \cdot x, x\right) \]
        3. associate-*l*99.9%

          \[\leadsto \mathsf{copysign}\left(x + \color{blue}{-0.16666666666666666 \cdot \left({x}^{2} \cdot x\right)}, x\right) \]
        4. unpow299.9%

          \[\leadsto \mathsf{copysign}\left(x + -0.16666666666666666 \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot x\right), x\right) \]
        5. unpow399.9%

          \[\leadsto \mathsf{copysign}\left(x + -0.16666666666666666 \cdot \color{blue}{{x}^{3}}, x\right) \]
      10. Simplified99.9%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x + -0.16666666666666666 \cdot {x}^{3}}, x\right) \]

      if 1.25 < x

      1. Initial program 49.0%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified49.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 98.7%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x \cdot \left(1 + \frac{\left|x\right|}{x}\right)\right)}, x\right) \]
      6. Step-by-step derivation
        1. +-commutative98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \color{blue}{\left(\frac{\left|x\right|}{x} + 1\right)}\right), x\right) \]
        2. rem-square-sqrt98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|}{x} + 1\right)\right), x\right) \]
        3. fabs-sqr98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\color{blue}{\sqrt{x} \cdot \sqrt{x}}}{x} + 1\right)\right), x\right) \]
        4. rem-square-sqrt98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\color{blue}{x}}{x} + 1\right)\right), x\right) \]
        5. *-inverses98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\color{blue}{1} + 1\right)\right), x\right) \]
        6. metadata-eval98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \color{blue}{2}\right), x\right) \]
      7. Simplified98.7%

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

    Alternative 5: 99.2% accurate, 1.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.3:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -1.3)
       (copysign (log (/ -0.5 x)) x)
       (if (<= x 1.25) (copysign x x) (copysign (log (* x 2.0)) x))))
    double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = copysign(log((-0.5 / x)), x);
    	} else if (x <= 1.25) {
    		tmp = copysign(x, x);
    	} else {
    		tmp = copysign(log((x * 2.0)), x);
    	}
    	return tmp;
    }
    
    public static double code(double x) {
    	double tmp;
    	if (x <= -1.3) {
    		tmp = Math.copySign(Math.log((-0.5 / x)), x);
    	} else if (x <= 1.25) {
    		tmp = Math.copySign(x, x);
    	} else {
    		tmp = Math.copySign(Math.log((x * 2.0)), x);
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if x <= -1.3:
    		tmp = math.copysign(math.log((-0.5 / x)), x)
    	elif x <= 1.25:
    		tmp = math.copysign(x, x)
    	else:
    		tmp = math.copysign(math.log((x * 2.0)), x)
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (x <= -1.3)
    		tmp = copysign(log(Float64(-0.5 / x)), x);
    	elseif (x <= 1.25)
    		tmp = copysign(x, x);
    	else
    		tmp = copysign(log(Float64(x * 2.0)), x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if (x <= -1.3)
    		tmp = sign(x) * abs(log((-0.5 / x)));
    	elseif (x <= 1.25)
    		tmp = sign(x) * abs(x);
    	else
    		tmp = sign(x) * abs(log((x * 2.0)));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[LessEqual[x, -1.3], N[With[{TMP1 = Abs[N[Log[N[(-0.5 / x), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], 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 * 2.0), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -1.3:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(\frac{-0.5}{x}\right), x\right)\\
    
    \mathbf{elif}\;x \leq 1.25:\\
    \;\;\;\;\mathsf{copysign}\left(x, x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -1.30000000000000004

      1. Initial program 54.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define54.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt0.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr0.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow24.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine4.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified4.7%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around -inf 99.5%

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

      if -1.30000000000000004 < x < 1.25

      1. Initial program 6.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow26.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around 0 99.6%

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

      if 1.25 < x

      1. Initial program 49.0%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified49.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 98.7%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x \cdot \left(1 + \frac{\left|x\right|}{x}\right)\right)}, x\right) \]
      6. Step-by-step derivation
        1. +-commutative98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \color{blue}{\left(\frac{\left|x\right|}{x} + 1\right)}\right), x\right) \]
        2. rem-square-sqrt98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|}{x} + 1\right)\right), x\right) \]
        3. fabs-sqr98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\color{blue}{\sqrt{x} \cdot \sqrt{x}}}{x} + 1\right)\right), x\right) \]
        4. rem-square-sqrt98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\color{blue}{x}}{x} + 1\right)\right), x\right) \]
        5. *-inverses98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\color{blue}{1} + 1\right)\right), x\right) \]
        6. metadata-eval98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \color{blue}{2}\right), x\right) \]
      7. Simplified98.7%

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

    Alternative 6: 82.1% accurate, 1.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -3.2:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\ \mathbf{elif}\;x \leq 1.25:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -3.2)
       (copysign (log (- x)) x)
       (if (<= x 1.25) (copysign x x) (copysign (log (* x 2.0)) x))))
    double code(double x) {
    	double tmp;
    	if (x <= -3.2) {
    		tmp = copysign(log(-x), x);
    	} else if (x <= 1.25) {
    		tmp = copysign(x, x);
    	} else {
    		tmp = copysign(log((x * 2.0)), x);
    	}
    	return tmp;
    }
    
    public static double code(double x) {
    	double tmp;
    	if (x <= -3.2) {
    		tmp = Math.copySign(Math.log(-x), x);
    	} else if (x <= 1.25) {
    		tmp = Math.copySign(x, x);
    	} else {
    		tmp = Math.copySign(Math.log((x * 2.0)), x);
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if x <= -3.2:
    		tmp = math.copysign(math.log(-x), x)
    	elif x <= 1.25:
    		tmp = math.copysign(x, x)
    	else:
    		tmp = math.copysign(math.log((x * 2.0)), x)
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (x <= -3.2)
    		tmp = copysign(log(Float64(-x)), x);
    	elseif (x <= 1.25)
    		tmp = copysign(x, x);
    	else
    		tmp = copysign(log(Float64(x * 2.0)), x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if (x <= -3.2)
    		tmp = sign(x) * abs(log(-x));
    	elseif (x <= 1.25)
    		tmp = sign(x) * abs(x);
    	else
    		tmp = sign(x) * abs(log((x * 2.0)));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[LessEqual[x, -3.2], N[With[{TMP1 = Abs[N[Log[(-x)], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], 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 * 2.0), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -3.2:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\
    
    \mathbf{elif}\;x \leq 1.25:\\
    \;\;\;\;\mathsf{copysign}\left(x, x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(x \cdot 2\right), x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if x < -3.2000000000000002

      1. Initial program 54.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define54.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around -inf 31.5%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(-1 \cdot x\right)}, x\right) \]
      6. Step-by-step derivation
        1. neg-mul-131.5%

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(-x\right)}, x\right) \]
      7. Simplified31.5%

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

      if -3.2000000000000002 < x < 1.25

      1. Initial program 6.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
      6. Step-by-step derivation
        1. rem-square-sqrt3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
        2. fabs-sqr3.3%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        3. rem-square-sqrt6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
        4. metadata-eval6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
        5. unpow26.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
        6. hypot-undefine6.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
      7. Simplified6.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
      8. Taylor expanded in x around 0 99.6%

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

      if 1.25 < x

      1. Initial program 49.0%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define49.0%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified49.0%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 98.7%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x \cdot \left(1 + \frac{\left|x\right|}{x}\right)\right)}, x\right) \]
      6. Step-by-step derivation
        1. +-commutative98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \color{blue}{\left(\frac{\left|x\right|}{x} + 1\right)}\right), x\right) \]
        2. rem-square-sqrt98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|}{x} + 1\right)\right), x\right) \]
        3. fabs-sqr98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\color{blue}{\sqrt{x} \cdot \sqrt{x}}}{x} + 1\right)\right), x\right) \]
        4. rem-square-sqrt98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\frac{\color{blue}{x}}{x} + 1\right)\right), x\right) \]
        5. *-inverses98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \left(\color{blue}{1} + 1\right)\right), x\right) \]
        6. metadata-eval98.7%

          \[\leadsto \mathsf{copysign}\left(\log \left(x \cdot \color{blue}{2}\right), x\right) \]
      7. Simplified98.7%

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

    Alternative 7: 64.9% accurate, 2.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -0.5:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\mathsf{log1p}\left(x\right), x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x -0.5) (copysign (log (- x)) x) (copysign (log1p x) x)))
    double code(double x) {
    	double tmp;
    	if (x <= -0.5) {
    		tmp = copysign(log(-x), x);
    	} else {
    		tmp = copysign(log1p(x), x);
    	}
    	return tmp;
    }
    
    public static double code(double x) {
    	double tmp;
    	if (x <= -0.5) {
    		tmp = Math.copySign(Math.log(-x), x);
    	} else {
    		tmp = Math.copySign(Math.log1p(x), x);
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if x <= -0.5:
    		tmp = math.copysign(math.log(-x), x)
    	else:
    		tmp = math.copysign(math.log1p(x), x)
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (x <= -0.5)
    		tmp = copysign(log(Float64(-x)), x);
    	else
    		tmp = copysign(log1p(x), x);
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[x, -0.5], N[With[{TMP1 = Abs[N[Log[(-x)], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], N[With[{TMP1 = Abs[N[Log[1 + x], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq -0.5:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\mathsf{log1p}\left(x\right), x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -0.5

      1. Initial program 54.8%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define54.8%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified54.8%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around -inf 31.5%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(-1 \cdot x\right)}, x\right) \]
      6. Step-by-step derivation
        1. neg-mul-131.5%

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(-x\right)}, x\right) \]
      7. Simplified31.5%

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

      if -0.5 < x

      1. Initial program 19.1%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. fma-define19.1%

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
      3. Simplified19.1%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
      4. Add Preprocessing
      5. Taylor expanded in x around 0 13.8%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(1 + \left|x\right|\right)}, x\right) \]
      6. Step-by-step derivation
        1. log1p-define79.5%

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\mathsf{log1p}\left(\left|x\right|\right)}, x\right) \]
        2. rem-square-sqrt40.8%

          \[\leadsto \mathsf{copysign}\left(\mathsf{log1p}\left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|\right), x\right) \]
        3. fabs-sqr40.8%

          \[\leadsto \mathsf{copysign}\left(\mathsf{log1p}\left(\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right), x\right) \]
        4. rem-square-sqrt79.5%

          \[\leadsto \mathsf{copysign}\left(\mathsf{log1p}\left(\color{blue}{x}\right), x\right) \]
      7. Simplified79.5%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\mathsf{log1p}\left(x\right)}, x\right) \]
    3. Recombined 2 regimes into one program.
    4. Add Preprocessing

    Alternative 8: 57.0% accurate, 2.0× speedup?

    \[\begin{array}{l} \\ \mathsf{copysign}\left(\mathsf{log1p}\left(x\right), x\right) \end{array} \]
    (FPCore (x) :precision binary64 (copysign (log1p x) x))
    double code(double x) {
    	return copysign(log1p(x), x);
    }
    
    public static double code(double x) {
    	return Math.copySign(Math.log1p(x), x);
    }
    
    def code(x):
    	return math.copysign(math.log1p(x), x)
    
    function code(x)
    	return copysign(log1p(x), x)
    end
    
    code[x_] := N[With[{TMP1 = Abs[N[Log[1 + x], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \mathsf{copysign}\left(\mathsf{log1p}\left(x\right), x\right)
    \end{array}
    
    Derivation
    1. Initial program 27.4%

      \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
    2. Step-by-step derivation
      1. fma-define27.5%

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
    3. Simplified27.5%

      \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 17.9%

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(1 + \left|x\right|\right)}, x\right) \]
    6. Step-by-step derivation
      1. log1p-define68.3%

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\mathsf{log1p}\left(\left|x\right|\right)}, x\right) \]
      2. rem-square-sqrt31.3%

        \[\leadsto \mathsf{copysign}\left(\mathsf{log1p}\left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|\right), x\right) \]
      3. fabs-sqr31.3%

        \[\leadsto \mathsf{copysign}\left(\mathsf{log1p}\left(\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right), x\right) \]
      4. rem-square-sqrt60.9%

        \[\leadsto \mathsf{copysign}\left(\mathsf{log1p}\left(\color{blue}{x}\right), x\right) \]
    7. Simplified60.9%

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\mathsf{log1p}\left(x\right)}, x\right) \]
    8. Add Preprocessing

    Alternative 9: 52.5% accurate, 4.0× 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 27.4%

      \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
    2. Step-by-step derivation
      1. fma-define27.5%

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}\right), x\right) \]
    3. Simplified27.5%

      \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\mathsf{fma}\left(x, x, 1\right)}\right), x\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 27.4%

      \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{1 + {x}^{2}}\right), x\right)} \]
    6. Step-by-step derivation
      1. rem-square-sqrt12.7%

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right| + \sqrt{1 + {x}^{2}}\right), x\right) \]
      2. fabs-sqr12.7%

        \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x} \cdot \sqrt{x}} + \sqrt{1 + {x}^{2}}\right), x\right) \]
      3. rem-square-sqrt15.7%

        \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + \sqrt{1 + {x}^{2}}\right), x\right) \]
      4. metadata-eval15.7%

        \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{\color{blue}{1 \cdot 1} + {x}^{2}}\right), x\right) \]
      5. unpow215.7%

        \[\leadsto \mathsf{copysign}\left(\log \left(x + \sqrt{1 \cdot 1 + \color{blue}{x \cdot x}}\right), x\right) \]
      6. hypot-undefine27.1%

        \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{\mathsf{hypot}\left(1, x\right)}\right), x\right) \]
    7. Simplified27.1%

      \[\leadsto \color{blue}{\mathsf{copysign}\left(\log \left(x + \mathsf{hypot}\left(1, x\right)\right), x\right)} \]
    8. Taylor expanded in x around 0 56.5%

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

    Developer Target 1: 99.9% accurate, 0.6× 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 2024157 
    (FPCore (x)
      :name "Rust f64::asinh"
      :precision binary64
    
      :alt
      (! :herbie-platform default (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))