ln(1 + x)

Percentage Accurate: 96.7% → 98.6%
Time: 13.3s
Alternatives: 7
Speedup: 1.0×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 7 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 96.7% accurate, 1.0× speedup?

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

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

Alternative 1: 98.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.6 \cdot 10^{-26} \lor \neg \left(x \leq 5.2 \cdot 10^{-26}\right):\\ \;\;\;\;\mathsf{log1p}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x + 1\right) + -1\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -2.6e-26) (not (<= x 5.2e-26))) (log1p x) (+ (+ x 1.0) -1.0)))
double code(double x) {
	double tmp;
	if ((x <= -2.6e-26) || !(x <= 5.2e-26)) {
		tmp = log1p(x);
	} else {
		tmp = (x + 1.0) + -1.0;
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if ((x <= -2.6e-26) || !(x <= 5.2e-26)) {
		tmp = Math.log1p(x);
	} else {
		tmp = (x + 1.0) + -1.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (x <= -2.6e-26) or not (x <= 5.2e-26):
		tmp = math.log1p(x)
	else:
		tmp = (x + 1.0) + -1.0
	return tmp
function code(x)
	tmp = 0.0
	if ((x <= -2.6e-26) || !(x <= 5.2e-26))
		tmp = log1p(x);
	else
		tmp = Float64(Float64(x + 1.0) + -1.0);
	end
	return tmp
end
code[x_] := If[Or[LessEqual[x, -2.6e-26], N[Not[LessEqual[x, 5.2e-26]], $MachinePrecision]], N[Log[1 + x], $MachinePrecision], N[(N[(x + 1.0), $MachinePrecision] + -1.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.6 \cdot 10^{-26} \lor \neg \left(x \leq 5.2 \cdot 10^{-26}\right):\\
\;\;\;\;\mathsf{log1p}\left(x\right)\\

\mathbf{else}:\\
\;\;\;\;\left(x + 1\right) + -1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -2.6000000000000001e-26 or 5.2000000000000002e-26 < x

    1. Initial program 89.4%

      \[\log \left(1 + x\right) \]
    2. Step-by-step derivation
      1. log1p-def95.3%

        \[\leadsto \color{blue}{\mathsf{log1p}\left(x\right)} \]
    3. Simplified95.3%

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

    if -2.6000000000000001e-26 < x < 5.2000000000000002e-26

    1. Initial program 100.0%

      \[\log \left(1 + x\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. add-cbrt-cube100.0%

        \[\leadsto \log \color{blue}{\left(\sqrt[3]{\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)}\right)} \]
      2. pow1/3100.0%

        \[\leadsto \log \color{blue}{\left({\left(\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)\right)}^{0.3333333333333333}\right)} \]
      3. log-pow100.0%

        \[\leadsto \color{blue}{0.3333333333333333 \cdot \log \left(\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)\right)} \]
      4. pow3100.0%

        \[\leadsto 0.3333333333333333 \cdot \log \color{blue}{\left({\left(1 + x\right)}^{3}\right)} \]
      5. log-pow100.0%

        \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(3 \cdot \log \left(1 + x\right)\right)} \]
      6. log1p-def5.4%

        \[\leadsto 0.3333333333333333 \cdot \left(3 \cdot \color{blue}{\mathsf{log1p}\left(x\right)}\right) \]
    4. Applied egg-rr5.4%

      \[\leadsto \color{blue}{0.3333333333333333 \cdot \left(3 \cdot \mathsf{log1p}\left(x\right)\right)} \]
    5. Taylor expanded in x around 0 5.4%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(3 \cdot x\right)} \]
    6. Step-by-step derivation
      1. *-commutative5.4%

        \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(x \cdot 3\right)} \]
    7. Simplified5.4%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(x \cdot 3\right)} \]
    8. Step-by-step derivation
      1. *-commutative5.4%

        \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(3 \cdot x\right)} \]
      2. associate-*r*5.4%

        \[\leadsto \color{blue}{\left(0.3333333333333333 \cdot 3\right) \cdot x} \]
      3. metadata-eval5.4%

        \[\leadsto \color{blue}{1} \cdot x \]
      4. expm1-log1p-u5.4%

        \[\leadsto 1 \cdot \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(x\right)\right)} \]
      5. *-un-lft-identity5.4%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(x\right)\right)} \]
      6. expm1-udef100.0%

        \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(x\right)} - 1} \]
      7. log1p-udef100.0%

        \[\leadsto e^{\color{blue}{\log \left(1 + x\right)}} - 1 \]
      8. rem-exp-log100.0%

        \[\leadsto \color{blue}{\left(1 + x\right)} - 1 \]
      9. +-commutative100.0%

        \[\leadsto \color{blue}{\left(x + 1\right)} - 1 \]
    9. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\left(x + 1\right) - 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.6 \cdot 10^{-26} \lor \neg \left(x \leq 5.2 \cdot 10^{-26}\right):\\ \;\;\;\;\mathsf{log1p}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x + 1\right) + -1\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 97.5% accurate, 0.2× speedup?

\[\begin{array}{l} \\ {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \left(\left(1 + \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}\right) + -1\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (*
  (pow (pow (log1p x) 16.0) 0.05555555555555555)
  (+ (+ 1.0 (cbrt (cbrt (log1p x)))) -1.0)))
double code(double x) {
	return pow(pow(log1p(x), 16.0), 0.05555555555555555) * ((1.0 + cbrt(cbrt(log1p(x)))) + -1.0);
}
public static double code(double x) {
	return Math.pow(Math.pow(Math.log1p(x), 16.0), 0.05555555555555555) * ((1.0 + Math.cbrt(Math.cbrt(Math.log1p(x)))) + -1.0);
}
function code(x)
	return Float64(((log1p(x) ^ 16.0) ^ 0.05555555555555555) * Float64(Float64(1.0 + cbrt(cbrt(log1p(x)))) + -1.0))
end
code[x_] := N[(N[Power[N[Power[N[Log[1 + x], $MachinePrecision], 16.0], $MachinePrecision], 0.05555555555555555], $MachinePrecision] * N[(N[(1.0 + N[Power[N[Power[N[Log[1 + x], $MachinePrecision], 1/3], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \left(\left(1 + \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}\right) + -1\right)
\end{array}
Derivation
  1. Initial program 96.3%

    \[\log \left(1 + x\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-cbrt-cube96.0%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \log \left(1 + x\right)}} \]
    2. pow1/394.4%

      \[\leadsto \color{blue}{{\left(\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \log \left(1 + x\right)\right)}^{0.3333333333333333}} \]
    3. add-cube-cbrt94.4%

      \[\leadsto {\left(\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \color{blue}{\left(\left(\sqrt[3]{\log \left(1 + x\right)} \cdot \sqrt[3]{\log \left(1 + x\right)}\right) \cdot \sqrt[3]{\log \left(1 + x\right)}\right)}\right)}^{0.3333333333333333} \]
    4. associate-*r*94.4%

      \[\leadsto {\color{blue}{\left(\left(\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \left(\sqrt[3]{\log \left(1 + x\right)} \cdot \sqrt[3]{\log \left(1 + x\right)}\right)\right) \cdot \sqrt[3]{\log \left(1 + x\right)}\right)}}^{0.3333333333333333} \]
    5. unpow-prod-down94.5%

      \[\leadsto \color{blue}{{\left(\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \left(\sqrt[3]{\log \left(1 + x\right)} \cdot \sqrt[3]{\log \left(1 + x\right)}\right)\right)}^{0.3333333333333333} \cdot {\left(\sqrt[3]{\log \left(1 + x\right)}\right)}^{0.3333333333333333}} \]
  4. Applied egg-rr76.8%

    \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{2}\right)}^{0.3333333333333333} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}} \]
  5. Step-by-step derivation
    1. unpow1/376.9%

      \[\leadsto \color{blue}{\sqrt[3]{{\left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{2}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    2. unpow276.9%

      \[\leadsto \sqrt[3]{\color{blue}{\left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right) \cdot \left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    3. rem-cube-cbrt76.7%

      \[\leadsto \sqrt[3]{\left(\color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{3}} \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right) \cdot \left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    4. pow-plus76.7%

      \[\leadsto \sqrt[3]{\color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\left(3 + 1\right)}} \cdot \left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    5. metadata-eval76.7%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\color{blue}{4}} \cdot \left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    6. rem-cube-cbrt76.6%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{4} \cdot \left(\color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{3}} \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    7. pow-plus76.6%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{4} \cdot \color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\left(3 + 1\right)}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    8. metadata-eval76.6%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{4} \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\color{blue}{4}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    9. pow-sqr76.6%

      \[\leadsto \sqrt[3]{\color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\left(2 \cdot 4\right)}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    10. metadata-eval76.6%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\color{blue}{8}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  6. Simplified76.6%

    \[\leadsto \color{blue}{\sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}} \]
  7. Step-by-step derivation
    1. pow1/376.6%

      \[\leadsto \color{blue}{{\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right)}^{0.3333333333333333}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    2. add-cbrt-cube93.5%

      \[\leadsto {\color{blue}{\left(\sqrt[3]{\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8} \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right) \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}}\right)}}^{0.3333333333333333} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    3. pow1/393.3%

      \[\leadsto {\color{blue}{\left({\left(\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8} \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right) \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right)}^{0.3333333333333333}\right)}}^{0.3333333333333333} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    4. pow-pow93.5%

      \[\leadsto \color{blue}{{\left(\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8} \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right) \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    5. pow393.5%

      \[\leadsto {\color{blue}{\left({\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right)}^{3}\right)}}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    6. pow1/357.8%

      \[\leadsto {\left({\left({\color{blue}{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{0.3333333333333333}\right)}}^{8}\right)}^{3}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    7. pow-pow57.8%

      \[\leadsto {\left({\color{blue}{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\left(0.3333333333333333 \cdot 8\right)}\right)}}^{3}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    8. pow-pow93.6%

      \[\leadsto {\color{blue}{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\left(\left(0.3333333333333333 \cdot 8\right) \cdot 3\right)}\right)}}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    9. metadata-eval93.6%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\left(\color{blue}{2.6666666666666665} \cdot 3\right)}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    10. metadata-eval93.6%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\color{blue}{8}}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    11. metadata-eval93.6%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{\color{blue}{0.1111111111111111}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  8. Applied egg-rr93.6%

    \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{0.1111111111111111}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  9. Step-by-step derivation
    1. expm1-log1p-u93.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{0.1111111111111111}\right)\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    2. expm1-udef95.8%

      \[\leadsto \color{blue}{\left(e^{\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{0.1111111111111111}\right)} - 1\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    3. sqr-pow95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left(\color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{\left(\frac{0.1111111111111111}{2}\right)} \cdot {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{\left(\frac{0.1111111111111111}{2}\right)}}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    4. pow-prod-down95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left(\color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8} \cdot {\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{\left(\frac{0.1111111111111111}{2}\right)}}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    5. pow-prod-up95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left({\color{blue}{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\left(8 + 8\right)}\right)}}^{\left(\frac{0.1111111111111111}{2}\right)}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    6. metadata-eval95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\color{blue}{16}}\right)}^{\left(\frac{0.1111111111111111}{2}\right)}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    7. metadata-eval95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{\color{blue}{0.05555555555555555}}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  10. Applied egg-rr95.8%

    \[\leadsto \color{blue}{\left(e^{\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555}\right)} - 1\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  11. Step-by-step derivation
    1. expm1-def97.3%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555}\right)\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    2. expm1-log1p97.3%

      \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  12. Simplified97.3%

    \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  13. Step-by-step derivation
    1. expm1-log1p-u97.4%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}\right)\right)} \]
    2. expm1-udef97.4%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \color{blue}{\left(e^{\mathsf{log1p}\left(\sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}\right)} - 1\right)} \]
    3. log1p-udef97.4%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \left(e^{\color{blue}{\log \left(1 + \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}\right)}} - 1\right) \]
    4. rem-exp-log97.4%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \left(\color{blue}{\left(1 + \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}\right)} - 1\right) \]
  14. Applied egg-rr97.4%

    \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \color{blue}{\left(\left(1 + \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}\right) - 1\right)} \]
  15. Final simplification97.4%

    \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \left(\left(1 + \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}\right) + -1\right) \]
  16. Add Preprocessing

Alternative 3: 97.5% accurate, 0.2× speedup?

\[\begin{array}{l} \\ {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \end{array} \]
(FPCore (x)
 :precision binary64
 (* (pow (pow (log1p x) 16.0) 0.05555555555555555) (cbrt (cbrt (log1p x)))))
double code(double x) {
	return pow(pow(log1p(x), 16.0), 0.05555555555555555) * cbrt(cbrt(log1p(x)));
}
public static double code(double x) {
	return Math.pow(Math.pow(Math.log1p(x), 16.0), 0.05555555555555555) * Math.cbrt(Math.cbrt(Math.log1p(x)));
}
function code(x)
	return Float64(((log1p(x) ^ 16.0) ^ 0.05555555555555555) * cbrt(cbrt(log1p(x))))
end
code[x_] := N[(N[Power[N[Power[N[Log[1 + x], $MachinePrecision], 16.0], $MachinePrecision], 0.05555555555555555], $MachinePrecision] * N[Power[N[Power[N[Log[1 + x], $MachinePrecision], 1/3], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}
\end{array}
Derivation
  1. Initial program 96.3%

    \[\log \left(1 + x\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-cbrt-cube96.0%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \log \left(1 + x\right)}} \]
    2. pow1/394.4%

      \[\leadsto \color{blue}{{\left(\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \log \left(1 + x\right)\right)}^{0.3333333333333333}} \]
    3. add-cube-cbrt94.4%

      \[\leadsto {\left(\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \color{blue}{\left(\left(\sqrt[3]{\log \left(1 + x\right)} \cdot \sqrt[3]{\log \left(1 + x\right)}\right) \cdot \sqrt[3]{\log \left(1 + x\right)}\right)}\right)}^{0.3333333333333333} \]
    4. associate-*r*94.4%

      \[\leadsto {\color{blue}{\left(\left(\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \left(\sqrt[3]{\log \left(1 + x\right)} \cdot \sqrt[3]{\log \left(1 + x\right)}\right)\right) \cdot \sqrt[3]{\log \left(1 + x\right)}\right)}}^{0.3333333333333333} \]
    5. unpow-prod-down94.5%

      \[\leadsto \color{blue}{{\left(\left(\log \left(1 + x\right) \cdot \log \left(1 + x\right)\right) \cdot \left(\sqrt[3]{\log \left(1 + x\right)} \cdot \sqrt[3]{\log \left(1 + x\right)}\right)\right)}^{0.3333333333333333} \cdot {\left(\sqrt[3]{\log \left(1 + x\right)}\right)}^{0.3333333333333333}} \]
  4. Applied egg-rr76.8%

    \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{2}\right)}^{0.3333333333333333} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}} \]
  5. Step-by-step derivation
    1. unpow1/376.9%

      \[\leadsto \color{blue}{\sqrt[3]{{\left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{2}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    2. unpow276.9%

      \[\leadsto \sqrt[3]{\color{blue}{\left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right) \cdot \left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    3. rem-cube-cbrt76.7%

      \[\leadsto \sqrt[3]{\left(\color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{3}} \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right) \cdot \left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    4. pow-plus76.7%

      \[\leadsto \sqrt[3]{\color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\left(3 + 1\right)}} \cdot \left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    5. metadata-eval76.7%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\color{blue}{4}} \cdot \left(\mathsf{log1p}\left(x\right) \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    6. rem-cube-cbrt76.6%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{4} \cdot \left(\color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{3}} \cdot \sqrt[3]{\mathsf{log1p}\left(x\right)}\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    7. pow-plus76.6%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{4} \cdot \color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\left(3 + 1\right)}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    8. metadata-eval76.6%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{4} \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\color{blue}{4}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    9. pow-sqr76.6%

      \[\leadsto \sqrt[3]{\color{blue}{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\left(2 \cdot 4\right)}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    10. metadata-eval76.6%

      \[\leadsto \sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{\color{blue}{8}}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  6. Simplified76.6%

    \[\leadsto \color{blue}{\sqrt[3]{{\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}}} \]
  7. Step-by-step derivation
    1. pow1/376.6%

      \[\leadsto \color{blue}{{\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right)}^{0.3333333333333333}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    2. add-cbrt-cube93.5%

      \[\leadsto {\color{blue}{\left(\sqrt[3]{\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8} \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right) \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}}\right)}}^{0.3333333333333333} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    3. pow1/393.3%

      \[\leadsto {\color{blue}{\left({\left(\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8} \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right) \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right)}^{0.3333333333333333}\right)}}^{0.3333333333333333} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    4. pow-pow93.5%

      \[\leadsto \color{blue}{{\left(\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8} \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right) \cdot {\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    5. pow393.5%

      \[\leadsto {\color{blue}{\left({\left({\left(\sqrt[3]{\mathsf{log1p}\left(x\right)}\right)}^{8}\right)}^{3}\right)}}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    6. pow1/357.8%

      \[\leadsto {\left({\left({\color{blue}{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{0.3333333333333333}\right)}}^{8}\right)}^{3}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    7. pow-pow57.8%

      \[\leadsto {\left({\color{blue}{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\left(0.3333333333333333 \cdot 8\right)}\right)}}^{3}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    8. pow-pow93.6%

      \[\leadsto {\color{blue}{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\left(\left(0.3333333333333333 \cdot 8\right) \cdot 3\right)}\right)}}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    9. metadata-eval93.6%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\left(\color{blue}{2.6666666666666665} \cdot 3\right)}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    10. metadata-eval93.6%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\color{blue}{8}}\right)}^{\left(0.3333333333333333 \cdot 0.3333333333333333\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    11. metadata-eval93.6%

      \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{\color{blue}{0.1111111111111111}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  8. Applied egg-rr93.6%

    \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{0.1111111111111111}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  9. Step-by-step derivation
    1. expm1-log1p-u93.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{0.1111111111111111}\right)\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    2. expm1-udef95.8%

      \[\leadsto \color{blue}{\left(e^{\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{0.1111111111111111}\right)} - 1\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    3. sqr-pow95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left(\color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{\left(\frac{0.1111111111111111}{2}\right)} \cdot {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{\left(\frac{0.1111111111111111}{2}\right)}}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    4. pow-prod-down95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left(\color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{8} \cdot {\left(\mathsf{log1p}\left(x\right)\right)}^{8}\right)}^{\left(\frac{0.1111111111111111}{2}\right)}}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    5. pow-prod-up95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left({\color{blue}{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\left(8 + 8\right)}\right)}}^{\left(\frac{0.1111111111111111}{2}\right)}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    6. metadata-eval95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{\color{blue}{16}}\right)}^{\left(\frac{0.1111111111111111}{2}\right)}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    7. metadata-eval95.8%

      \[\leadsto \left(e^{\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{\color{blue}{0.05555555555555555}}\right)} - 1\right) \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  10. Applied egg-rr95.8%

    \[\leadsto \color{blue}{\left(e^{\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555}\right)} - 1\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  11. Step-by-step derivation
    1. expm1-def97.3%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left({\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555}\right)\right)} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
    2. expm1-log1p97.3%

      \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  12. Simplified97.3%

    \[\leadsto \color{blue}{{\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555}} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  13. Final simplification97.3%

    \[\leadsto {\left({\left(\mathsf{log1p}\left(x\right)\right)}^{16}\right)}^{0.05555555555555555} \cdot \sqrt[3]{\sqrt[3]{\mathsf{log1p}\left(x\right)}} \]
  14. Add Preprocessing

Alternative 4: 97.5% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.6 \cdot 10^{-26}:\\ \;\;\;\;0.3333333333333333 \cdot \left(\mathsf{log1p}\left(x\right) \cdot 3\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + 1\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -2.6e-26) (* 0.3333333333333333 (* (log1p x) 3.0)) (log (+ x 1.0))))
double code(double x) {
	double tmp;
	if (x <= -2.6e-26) {
		tmp = 0.3333333333333333 * (log1p(x) * 3.0);
	} else {
		tmp = log((x + 1.0));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= -2.6e-26) {
		tmp = 0.3333333333333333 * (Math.log1p(x) * 3.0);
	} else {
		tmp = Math.log((x + 1.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -2.6e-26:
		tmp = 0.3333333333333333 * (math.log1p(x) * 3.0)
	else:
		tmp = math.log((x + 1.0))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -2.6e-26)
		tmp = Float64(0.3333333333333333 * Float64(log1p(x) * 3.0));
	else
		tmp = log(Float64(x + 1.0));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -2.6e-26], N[(0.3333333333333333 * N[(N[Log[1 + x], $MachinePrecision] * 3.0), $MachinePrecision]), $MachinePrecision], N[Log[N[(x + 1.0), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.6 \cdot 10^{-26}:\\
\;\;\;\;0.3333333333333333 \cdot \left(\mathsf{log1p}\left(x\right) \cdot 3\right)\\

\mathbf{else}:\\
\;\;\;\;\log \left(x + 1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -2.6000000000000001e-26

    1. Initial program 29.1%

      \[\log \left(1 + x\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. add-cbrt-cube27.5%

        \[\leadsto \log \color{blue}{\left(\sqrt[3]{\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)}\right)} \]
      2. pow1/329.1%

        \[\leadsto \log \color{blue}{\left({\left(\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)\right)}^{0.3333333333333333}\right)} \]
      3. log-pow29.1%

        \[\leadsto \color{blue}{0.3333333333333333 \cdot \log \left(\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)\right)} \]
      4. pow328.9%

        \[\leadsto 0.3333333333333333 \cdot \log \color{blue}{\left({\left(1 + x\right)}^{3}\right)} \]
      5. log-pow29.1%

        \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(3 \cdot \log \left(1 + x\right)\right)} \]
      6. log1p-def68.4%

        \[\leadsto 0.3333333333333333 \cdot \left(3 \cdot \color{blue}{\mathsf{log1p}\left(x\right)}\right) \]
    4. Applied egg-rr68.4%

      \[\leadsto \color{blue}{0.3333333333333333 \cdot \left(3 \cdot \mathsf{log1p}\left(x\right)\right)} \]

    if -2.6000000000000001e-26 < x

    1. Initial program 99.3%

      \[\log \left(1 + x\right) \]
    2. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification98.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.6 \cdot 10^{-26}:\\ \;\;\;\;0.3333333333333333 \cdot \left(\mathsf{log1p}\left(x\right) \cdot 3\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + 1\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 97.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2.6 \cdot 10^{-26}:\\ \;\;\;\;\mathsf{log1p}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + 1\right)\\ \end{array} \end{array} \]
(FPCore (x) :precision binary64 (if (<= x -2.6e-26) (log1p x) (log (+ x 1.0))))
double code(double x) {
	double tmp;
	if (x <= -2.6e-26) {
		tmp = log1p(x);
	} else {
		tmp = log((x + 1.0));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= -2.6e-26) {
		tmp = Math.log1p(x);
	} else {
		tmp = Math.log((x + 1.0));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -2.6e-26:
		tmp = math.log1p(x)
	else:
		tmp = math.log((x + 1.0))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -2.6e-26)
		tmp = log1p(x);
	else
		tmp = log(Float64(x + 1.0));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -2.6e-26], N[Log[1 + x], $MachinePrecision], N[Log[N[(x + 1.0), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.6 \cdot 10^{-26}:\\
\;\;\;\;\mathsf{log1p}\left(x\right)\\

\mathbf{else}:\\
\;\;\;\;\log \left(x + 1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -2.6000000000000001e-26

    1. Initial program 29.1%

      \[\log \left(1 + x\right) \]
    2. Step-by-step derivation
      1. log1p-def68.4%

        \[\leadsto \color{blue}{\mathsf{log1p}\left(x\right)} \]
    3. Simplified68.4%

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

    if -2.6000000000000001e-26 < x

    1. Initial program 99.3%

      \[\log \left(1 + x\right) \]
    2. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification97.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -2.6 \cdot 10^{-26}:\\ \;\;\;\;\mathsf{log1p}\left(x\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + 1\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 64.3% accurate, 20.6× speedup?

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

\\
\left(x + 1\right) + -1
\end{array}
Derivation
  1. Initial program 96.3%

    \[\log \left(1 + x\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-cbrt-cube79.9%

      \[\leadsto \log \color{blue}{\left(\sqrt[3]{\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)}\right)} \]
    2. pow1/379.9%

      \[\leadsto \log \color{blue}{\left({\left(\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)\right)}^{0.3333333333333333}\right)} \]
    3. log-pow79.9%

      \[\leadsto \color{blue}{0.3333333333333333 \cdot \log \left(\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(1 + x\right)\right)} \]
    4. pow379.9%

      \[\leadsto 0.3333333333333333 \cdot \log \color{blue}{\left({\left(1 + x\right)}^{3}\right)} \]
    5. log-pow96.1%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(3 \cdot \log \left(1 + x\right)\right)} \]
    6. log1p-def36.9%

      \[\leadsto 0.3333333333333333 \cdot \left(3 \cdot \color{blue}{\mathsf{log1p}\left(x\right)}\right) \]
  4. Applied egg-rr36.9%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \left(3 \cdot \mathsf{log1p}\left(x\right)\right)} \]
  5. Taylor expanded in x around 0 8.1%

    \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(3 \cdot x\right)} \]
  6. Step-by-step derivation
    1. *-commutative8.1%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(x \cdot 3\right)} \]
  7. Simplified8.1%

    \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(x \cdot 3\right)} \]
  8. Step-by-step derivation
    1. *-commutative8.1%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(3 \cdot x\right)} \]
    2. associate-*r*8.1%

      \[\leadsto \color{blue}{\left(0.3333333333333333 \cdot 3\right) \cdot x} \]
    3. metadata-eval8.1%

      \[\leadsto \color{blue}{1} \cdot x \]
    4. expm1-log1p-u8.1%

      \[\leadsto 1 \cdot \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(x\right)\right)} \]
    5. *-un-lft-identity8.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(x\right)\right)} \]
    6. expm1-udef67.6%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(x\right)} - 1} \]
    7. log1p-udef67.6%

      \[\leadsto e^{\color{blue}{\log \left(1 + x\right)}} - 1 \]
    8. rem-exp-log67.6%

      \[\leadsto \color{blue}{\left(1 + x\right)} - 1 \]
    9. +-commutative67.6%

      \[\leadsto \color{blue}{\left(x + 1\right)} - 1 \]
  9. Applied egg-rr67.6%

    \[\leadsto \color{blue}{\left(x + 1\right) - 1} \]
  10. Final simplification67.6%

    \[\leadsto \left(x + 1\right) + -1 \]
  11. Add Preprocessing

Alternative 7: 8.0% accurate, 103.0× speedup?

\[\begin{array}{l} \\ x \end{array} \]
(FPCore (x) :precision binary64 x)
double code(double x) {
	return x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x
end function
public static double code(double x) {
	return x;
}
def code(x):
	return x
function code(x)
	return x
end
function tmp = code(x)
	tmp = x;
end
code[x_] := x
\begin{array}{l}

\\
x
\end{array}
Derivation
  1. Initial program 96.3%

    \[\log \left(1 + x\right) \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 8.1%

    \[\leadsto \color{blue}{x} \]
  4. Final simplification8.1%

    \[\leadsto x \]
  5. Add Preprocessing

Developer target: 40.7% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;1 + x = 1:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;\frac{x \cdot \log \left(1 + x\right)}{\left(1 + x\right) - 1}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (== (+ 1.0 x) 1.0) x (/ (* x (log (+ 1.0 x))) (- (+ 1.0 x) 1.0))))
double code(double x) {
	double tmp;
	if ((1.0 + x) == 1.0) {
		tmp = x;
	} else {
		tmp = (x * log((1.0 + x))) / ((1.0 + x) - 1.0);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((1.0d0 + x) == 1.0d0) then
        tmp = x
    else
        tmp = (x * log((1.0d0 + x))) / ((1.0d0 + x) - 1.0d0)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if ((1.0 + x) == 1.0) {
		tmp = x;
	} else {
		tmp = (x * Math.log((1.0 + x))) / ((1.0 + x) - 1.0);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (1.0 + x) == 1.0:
		tmp = x
	else:
		tmp = (x * math.log((1.0 + x))) / ((1.0 + x) - 1.0)
	return tmp
function code(x)
	tmp = 0.0
	if (Float64(1.0 + x) == 1.0)
		tmp = x;
	else
		tmp = Float64(Float64(x * log(Float64(1.0 + x))) / Float64(Float64(1.0 + x) - 1.0));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if ((1.0 + x) == 1.0)
		tmp = x;
	else
		tmp = (x * log((1.0 + x))) / ((1.0 + x) - 1.0);
	end
	tmp_2 = tmp;
end
code[x_] := If[Equal[N[(1.0 + x), $MachinePrecision], 1.0], x, N[(N[(x * N[Log[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(N[(1.0 + x), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;1 + x = 1:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;\frac{x \cdot \log \left(1 + x\right)}{\left(1 + x\right) - 1}\\


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024031 
(FPCore (x)
  :name "ln(1 + x)"
  :precision binary64

  :herbie-target
  (if (== (+ 1.0 x) 1.0) x (/ (* x (log (+ 1.0 x))) (- (+ 1.0 x) 1.0)))

  (log (+ 1.0 x)))