Rust f64::acosh

Percentage Accurate: 51.0% → 99.7%
Time: 11.2s
Alternatives: 7
Speedup: 2.0×

Specification

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

\\
\cosh^{-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 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: 51.0% accurate, 1.0× speedup?

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

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

Alternative 1: 99.7% accurate, 1.6× speedup?

\[\begin{array}{l} \\ 0 - \log \left(\frac{-1}{\frac{0.5}{x} - x \cdot \left(\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)} + 2\right)}\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (-
  0.0
  (log
   (/
    -1.0
    (-
     (/ 0.5 x)
     (* x (+ (/ (+ -0.125 (/ -0.0625 (* x x))) (* x (* x (* x x)))) 2.0)))))))
double code(double x) {
	return 0.0 - log((-1.0 / ((0.5 / x) - (x * (((-0.125 + (-0.0625 / (x * x))) / (x * (x * (x * x)))) + 2.0)))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.0d0 - log(((-1.0d0) / ((0.5d0 / x) - (x * ((((-0.125d0) + ((-0.0625d0) / (x * x))) / (x * (x * (x * x)))) + 2.0d0)))))
end function
public static double code(double x) {
	return 0.0 - Math.log((-1.0 / ((0.5 / x) - (x * (((-0.125 + (-0.0625 / (x * x))) / (x * (x * (x * x)))) + 2.0)))));
}
def code(x):
	return 0.0 - math.log((-1.0 / ((0.5 / x) - (x * (((-0.125 + (-0.0625 / (x * x))) / (x * (x * (x * x)))) + 2.0)))))
function code(x)
	return Float64(0.0 - log(Float64(-1.0 / Float64(Float64(0.5 / x) - Float64(x * Float64(Float64(Float64(-0.125 + Float64(-0.0625 / Float64(x * x))) / Float64(x * Float64(x * Float64(x * x)))) + 2.0))))))
end
function tmp = code(x)
	tmp = 0.0 - log((-1.0 / ((0.5 / x) - (x * (((-0.125 + (-0.0625 / (x * x))) / (x * (x * (x * x)))) + 2.0)))));
end
code[x_] := N[(0.0 - N[Log[N[(-1.0 / N[(N[(0.5 / x), $MachinePrecision] - N[(x * N[(N[(N[(-0.125 + N[(-0.0625 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0 - \log \left(\frac{-1}{\frac{0.5}{x} - x \cdot \left(\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)} + 2\right)}\right)
\end{array}
Derivation
  1. Initial program 48.5%

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

    \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{\left(x \cdot \left(\left(1 + -1 \cdot \frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right) - \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right)\right) \]
  4. Simplified99.1%

    \[\leadsto \log \left(x + \color{blue}{\left(1 \cdot \frac{-0.5}{x} + x \cdot \left(1 + \frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right)}\right) \]
  5. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \mathsf{log.f64}\left(\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right) + x\right)\right) \]
    2. associate-+l+N/A

      \[\leadsto \mathsf{log.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x}\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    4. *-lft-identityN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(\frac{\frac{-1}{2}}{x}\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    6. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{+.f64}\left(\left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right), x\right)\right)\right) \]
  6. Applied egg-rr99.1%

    \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x} + \left(x \cdot \left(1 + \frac{-0.125 + \frac{-0.0625}{x \cdot x}}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) + x\right)\right)} \]
  7. Applied egg-rr99.1%

    \[\leadsto \color{blue}{-\log \left(\frac{1}{\frac{-0.5}{x} + \left(\left(1 + \frac{\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1\right) \cdot x}\right)} \]
  8. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \left(\left(\left(1 + \frac{\frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1\right) \cdot x + \frac{\frac{-1}{2}}{x}\right)\right)\right)\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot \left(\left(1 + \frac{\frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1\right) + \frac{\frac{-1}{2}}{x}\right)\right)\right)\right) \]
    3. fma-defineN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(x, \left(1 + \frac{\frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1, \frac{\frac{-1}{2}}{x}\right)\right)\right)\right)\right) \]
    4. frac-2negN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(x, \left(1 + \frac{\frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1, \frac{\mathsf{neg}\left(\frac{-1}{2}\right)}{\mathsf{neg}\left(x\right)}\right)\right)\right)\right)\right) \]
    5. distribute-frac-neg2N/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(x, \left(1 + \frac{\frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1, \mathsf{neg}\left(\frac{\mathsf{neg}\left(\frac{-1}{2}\right)}{x}\right)\right)\right)\right)\right)\right) \]
    6. distribute-neg-fracN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(x, \left(1 + \frac{\frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1, \mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{\frac{-1}{2}}{x}\right)\right)\right)\right)\right)\right)\right)\right) \]
    7. fmm-undefN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot \left(\left(1 + \frac{\frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1\right) - \left(\mathsf{neg}\left(\frac{\frac{-1}{2}}{x}\right)\right)\right)\right)\right)\right) \]
  9. Applied egg-rr99.1%

    \[\leadsto -\log \left(\frac{1}{\color{blue}{x \cdot \left(\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)} + 2\right) - \frac{0.5}{x}}}\right) \]
  10. Final simplification99.1%

    \[\leadsto 0 - \log \left(\frac{-1}{\frac{0.5}{x} - x \cdot \left(\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)} + 2\right)}\right) \]
  11. Add Preprocessing

Alternative 2: 99.7% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \log \left(\frac{-0.5}{x} + \left(x + x \cdot \left(\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)} + 1\right)\right)\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (log
  (+
   (/ -0.5 x)
   (+
    x
    (* x (+ (/ (+ -0.125 (/ -0.0625 (* x x))) (* (* x x) (* x x))) 1.0))))))
double code(double x) {
	return log(((-0.5 / x) + (x + (x * (((-0.125 + (-0.0625 / (x * x))) / ((x * x) * (x * x))) + 1.0)))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((((-0.5d0) / x) + (x + (x * ((((-0.125d0) + ((-0.0625d0) / (x * x))) / ((x * x) * (x * x))) + 1.0d0)))))
end function
public static double code(double x) {
	return Math.log(((-0.5 / x) + (x + (x * (((-0.125 + (-0.0625 / (x * x))) / ((x * x) * (x * x))) + 1.0)))));
}
def code(x):
	return math.log(((-0.5 / x) + (x + (x * (((-0.125 + (-0.0625 / (x * x))) / ((x * x) * (x * x))) + 1.0)))))
function code(x)
	return log(Float64(Float64(-0.5 / x) + Float64(x + Float64(x * Float64(Float64(Float64(-0.125 + Float64(-0.0625 / Float64(x * x))) / Float64(Float64(x * x) * Float64(x * x))) + 1.0)))))
end
function tmp = code(x)
	tmp = log(((-0.5 / x) + (x + (x * (((-0.125 + (-0.0625 / (x * x))) / ((x * x) * (x * x))) + 1.0)))));
end
code[x_] := N[Log[N[(N[(-0.5 / x), $MachinePrecision] + N[(x + N[(x * N[(N[(N[(-0.125 + N[(-0.0625 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\log \left(\frac{-0.5}{x} + \left(x + x \cdot \left(\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)} + 1\right)\right)\right)
\end{array}
Derivation
  1. Initial program 48.5%

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

    \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{\left(x \cdot \left(\left(1 + -1 \cdot \frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right) - \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right)\right) \]
  4. Simplified99.1%

    \[\leadsto \log \left(x + \color{blue}{\left(1 \cdot \frac{-0.5}{x} + x \cdot \left(1 + \frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right)}\right) \]
  5. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \mathsf{log.f64}\left(\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right) + x\right)\right) \]
    2. associate-+l+N/A

      \[\leadsto \mathsf{log.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x}\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    4. *-lft-identityN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(\frac{\frac{-1}{2}}{x}\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    6. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{+.f64}\left(\left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right), x\right)\right)\right) \]
  6. Applied egg-rr99.1%

    \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x} + \left(x \cdot \left(1 + \frac{-0.125 + \frac{-0.0625}{x \cdot x}}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) + x\right)\right)} \]
  7. Final simplification99.1%

    \[\leadsto \log \left(\frac{-0.5}{x} + \left(x + x \cdot \left(\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)} + 1\right)\right)\right) \]
  8. Add Preprocessing

Alternative 3: 99.7% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \log \left(\frac{-0.5}{x} + x \cdot \left(2 - \frac{\frac{0.0625}{x \cdot x} + 0.125}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right)\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (log
  (+
   (/ -0.5 x)
   (* x (- 2.0 (/ (+ (/ 0.0625 (* x x)) 0.125) (* (* x x) (* x x))))))))
double code(double x) {
	return log(((-0.5 / x) + (x * (2.0 - (((0.0625 / (x * x)) + 0.125) / ((x * x) * (x * x)))))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((((-0.5d0) / x) + (x * (2.0d0 - (((0.0625d0 / (x * x)) + 0.125d0) / ((x * x) * (x * x)))))))
end function
public static double code(double x) {
	return Math.log(((-0.5 / x) + (x * (2.0 - (((0.0625 / (x * x)) + 0.125) / ((x * x) * (x * x)))))));
}
def code(x):
	return math.log(((-0.5 / x) + (x * (2.0 - (((0.0625 / (x * x)) + 0.125) / ((x * x) * (x * x)))))))
function code(x)
	return log(Float64(Float64(-0.5 / x) + Float64(x * Float64(2.0 - Float64(Float64(Float64(0.0625 / Float64(x * x)) + 0.125) / Float64(Float64(x * x) * Float64(x * x)))))))
end
function tmp = code(x)
	tmp = log(((-0.5 / x) + (x * (2.0 - (((0.0625 / (x * x)) + 0.125) / ((x * x) * (x * x)))))));
end
code[x_] := N[Log[N[(N[(-0.5 / x), $MachinePrecision] + N[(x * N[(2.0 - N[(N[(N[(0.0625 / N[(x * x), $MachinePrecision]), $MachinePrecision] + 0.125), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\log \left(\frac{-0.5}{x} + x \cdot \left(2 - \frac{\frac{0.0625}{x \cdot x} + 0.125}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right)\right)
\end{array}
Derivation
  1. Initial program 48.5%

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

    \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{\left(x \cdot \left(\left(1 + -1 \cdot \frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right) - \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right)\right) \]
  4. Simplified99.1%

    \[\leadsto \log \left(x + \color{blue}{\left(1 \cdot \frac{-0.5}{x} + x \cdot \left(1 + \frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right)}\right) \]
  5. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \mathsf{log.f64}\left(\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right) + x\right)\right) \]
    2. associate-+l+N/A

      \[\leadsto \mathsf{log.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x}\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    4. *-lft-identityN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(\frac{\frac{-1}{2}}{x}\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    6. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{+.f64}\left(\left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right), x\right)\right)\right) \]
  6. Applied egg-rr99.1%

    \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x} + \left(x \cdot \left(1 + \frac{-0.125 + \frac{-0.0625}{x \cdot x}}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) + x\right)\right)} \]
  7. Taylor expanded in x around inf

    \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \color{blue}{\left(x \cdot \left(2 + -1 \cdot \frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right)\right)}\right)\right) \]
  8. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \left(2 + -1 \cdot \frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right)\right)\right)\right) \]
    2. mul-1-negN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \left(2 + \left(\mathsf{neg}\left(\frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right)\right)\right)\right)\right)\right) \]
    3. unsub-negN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \left(2 - \frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right)\right)\right)\right) \]
    4. --lowering--.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \left(\frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right)\right)\right)\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\left(\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}\right), \left({x}^{4}\right)\right)\right)\right)\right)\right) \]
    6. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \left(\frac{1}{16} \cdot \frac{1}{{x}^{2}}\right)\right), \left({x}^{4}\right)\right)\right)\right)\right)\right) \]
    7. associate-*r/N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \left(\frac{\frac{1}{16} \cdot 1}{{x}^{2}}\right)\right), \left({x}^{4}\right)\right)\right)\right)\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \left(\frac{\frac{1}{16}}{{x}^{2}}\right)\right), \left({x}^{4}\right)\right)\right)\right)\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \left({x}^{2}\right)\right)\right), \left({x}^{4}\right)\right)\right)\right)\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \left(x \cdot x\right)\right)\right), \left({x}^{4}\right)\right)\right)\right)\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \mathsf{*.f64}\left(x, x\right)\right)\right), \left({x}^{4}\right)\right)\right)\right)\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \mathsf{*.f64}\left(x, x\right)\right)\right), \left({x}^{\left(2 \cdot 2\right)}\right)\right)\right)\right)\right)\right) \]
    13. pow-sqrN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \mathsf{*.f64}\left(x, x\right)\right)\right), \left({x}^{2} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
    14. *-lowering-*.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \mathsf{*.f64}\left(x, x\right)\right)\right), \mathsf{*.f64}\left(\left({x}^{2}\right), \left({x}^{2}\right)\right)\right)\right)\right)\right)\right) \]
    15. unpow2N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \mathsf{*.f64}\left(x, x\right)\right)\right), \mathsf{*.f64}\left(\left(x \cdot x\right), \left({x}^{2}\right)\right)\right)\right)\right)\right)\right) \]
    16. *-lowering-*.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \mathsf{*.f64}\left(x, x\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left({x}^{2}\right)\right)\right)\right)\right)\right)\right) \]
    17. unpow2N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \mathsf{*.f64}\left(x, x\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(x \cdot x\right)\right)\right)\right)\right)\right)\right) \]
    18. *-lowering-*.f6499.1%

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{8}, \mathsf{/.f64}\left(\frac{1}{16}, \mathsf{*.f64}\left(x, x\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(x, x\right)\right)\right)\right)\right)\right)\right) \]
  9. Simplified99.1%

    \[\leadsto \log \left(\frac{-0.5}{x} + \color{blue}{x \cdot \left(2 - \frac{0.125 + \frac{0.0625}{x \cdot x}}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right)}\right) \]
  10. Final simplification99.1%

    \[\leadsto \log \left(\frac{-0.5}{x} + x \cdot \left(2 - \frac{\frac{0.0625}{x \cdot x} + 0.125}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right)\right) \]
  11. Add Preprocessing

Alternative 4: 99.6% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \log \left(x + \left(x + \frac{\frac{-0.125}{x \cdot x} - 0.5}{x}\right)\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (log (+ x (+ x (/ (- (/ -0.125 (* x x)) 0.5) x)))))
double code(double x) {
	return log((x + (x + (((-0.125 / (x * x)) - 0.5) / x))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((x + (x + ((((-0.125d0) / (x * x)) - 0.5d0) / x))))
end function
public static double code(double x) {
	return Math.log((x + (x + (((-0.125 / (x * x)) - 0.5) / x))));
}
def code(x):
	return math.log((x + (x + (((-0.125 / (x * x)) - 0.5) / x))))
function code(x)
	return log(Float64(x + Float64(x + Float64(Float64(Float64(-0.125 / Float64(x * x)) - 0.5) / x))))
end
function tmp = code(x)
	tmp = log((x + (x + (((-0.125 / (x * x)) - 0.5) / x))));
end
code[x_] := N[Log[N[(x + N[(x + N[(N[(N[(-0.125 / N[(x * x), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\log \left(x + \left(x + \frac{\frac{-0.125}{x \cdot x} - 0.5}{x}\right)\right)
\end{array}
Derivation
  1. Initial program 48.5%

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

    \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{\left(x \cdot \left(1 + -1 \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{{x}^{2}}\right)\right)}\right)\right) \]
  4. Step-by-step derivation
    1. distribute-lft-inN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x \cdot 1 + x \cdot \left(-1 \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{{x}^{2}}\right)\right)\right)\right) \]
    2. *-rgt-identityN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x + x \cdot \left(-1 \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{{x}^{2}}\right)\right)\right)\right) \]
    3. cancel-sign-subN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \left(\mathsf{neg}\left(x\right)\right) \cdot \left(-1 \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{{x}^{2}}\right)\right)\right)\right) \]
    4. distribute-lft-neg-inN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \left(\mathsf{neg}\left(x \cdot \left(-1 \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{{x}^{2}}\right)\right)\right)\right)\right)\right) \]
    5. mul-1-negN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \left(\mathsf{neg}\left(x \cdot \left(\mathsf{neg}\left(\frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{{x}^{2}}\right)\right)\right)\right)\right)\right)\right) \]
    6. distribute-rgt-neg-outN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{{x}^{2}}\right)\right)\right)\right)\right)\right)\right) \]
    7. remove-double-negN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - x \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{{x}^{2}}\right)\right)\right) \]
    8. associate-*r/N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \frac{x \cdot \left(\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}{{x}^{2}}\right)\right)\right) \]
    9. unpow2N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \frac{x \cdot \left(\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}\right)}{x \cdot x}\right)\right)\right) \]
    10. times-fracN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \frac{x}{x} \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)\right)\right) \]
    11. *-inversesN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - 1 \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \left(\mathsf{neg}\left(-1\right)\right) \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)\right)\right) \]
    13. distribute-lft-neg-inN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \left(\mathsf{neg}\left(-1 \cdot \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)\right)\right)\right)\right) \]
    14. neg-mul-1N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)\right)\right)\right)\right)\right)\right) \]
    15. remove-double-negN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \left(x - \frac{\frac{1}{2} + \frac{1}{8} \cdot \frac{1}{{x}^{2}}}{x}\right)\right)\right) \]
  5. Simplified99.0%

    \[\leadsto \log \left(x + \color{blue}{\left(x - \frac{0.5 - \frac{-0.125}{x \cdot x}}{x}\right)}\right) \]
  6. Final simplification99.0%

    \[\leadsto \log \left(x + \left(x + \frac{\frac{-0.125}{x \cdot x} - 0.5}{x}\right)\right) \]
  7. Add Preprocessing

Alternative 5: 99.5% accurate, 1.8× speedup?

\[\begin{array}{l} \\ 0 - \log \left(\frac{1}{x \cdot \left(2 + \frac{-0.5}{x \cdot x}\right)}\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (- 0.0 (log (/ 1.0 (* x (+ 2.0 (/ -0.5 (* x x))))))))
double code(double x) {
	return 0.0 - log((1.0 / (x * (2.0 + (-0.5 / (x * x))))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.0d0 - log((1.0d0 / (x * (2.0d0 + ((-0.5d0) / (x * x))))))
end function
public static double code(double x) {
	return 0.0 - Math.log((1.0 / (x * (2.0 + (-0.5 / (x * x))))));
}
def code(x):
	return 0.0 - math.log((1.0 / (x * (2.0 + (-0.5 / (x * x))))))
function code(x)
	return Float64(0.0 - log(Float64(1.0 / Float64(x * Float64(2.0 + Float64(-0.5 / Float64(x * x)))))))
end
function tmp = code(x)
	tmp = 0.0 - log((1.0 / (x * (2.0 + (-0.5 / (x * x))))));
end
code[x_] := N[(0.0 - N[Log[N[(1.0 / N[(x * N[(2.0 + N[(-0.5 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0 - \log \left(\frac{1}{x \cdot \left(2 + \frac{-0.5}{x \cdot x}\right)}\right)
\end{array}
Derivation
  1. Initial program 48.5%

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

    \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{\left(x \cdot \left(\left(1 + -1 \cdot \frac{\frac{1}{8} + \frac{1}{16} \cdot \frac{1}{{x}^{2}}}{{x}^{4}}\right) - \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right)\right) \]
  4. Simplified99.1%

    \[\leadsto \log \left(x + \color{blue}{\left(1 \cdot \frac{-0.5}{x} + x \cdot \left(1 + \frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right)}\right) \]
  5. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \mathsf{log.f64}\left(\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right) + x\right)\right) \]
    2. associate-+l+N/A

      \[\leadsto \mathsf{log.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x}\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    4. *-lft-identityN/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(\frac{\frac{-1}{2}}{x}\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right) + x\right)\right)\right) \]
    6. +-lowering-+.f64N/A

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, x\right), \mathsf{+.f64}\left(\left(x \cdot \left(1 + \frac{\frac{-1}{8} + \frac{\frac{-1}{16}}{x \cdot x}}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\right)\right), x\right)\right)\right) \]
  6. Applied egg-rr99.1%

    \[\leadsto \log \color{blue}{\left(\frac{-0.5}{x} + \left(x \cdot \left(1 + \frac{-0.125 + \frac{-0.0625}{x \cdot x}}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) + x\right)\right)} \]
  7. Applied egg-rr99.1%

    \[\leadsto \color{blue}{-\log \left(\frac{1}{\frac{-0.5}{x} + \left(\left(1 + \frac{\frac{-0.125 + \frac{-0.0625}{x \cdot x}}{x}}{x \cdot \left(x \cdot x\right)}\right) + 1\right) \cdot x}\right)} \]
  8. Taylor expanded in x around inf

    \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \color{blue}{\left(x \cdot \left(2 - \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)}\right)\right)\right) \]
  9. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \left(2 - \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)\right)\right) \]
    2. sub-negN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \left(2 + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)\right)\right)\right)\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(2, \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)\right)\right)\right)\right)\right)\right) \]
    4. associate-*r/N/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(2, \left(\mathsf{neg}\left(\frac{\frac{1}{2} \cdot 1}{{x}^{2}}\right)\right)\right)\right)\right)\right)\right) \]
    5. metadata-evalN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(2, \left(\mathsf{neg}\left(\frac{\frac{1}{2}}{{x}^{2}}\right)\right)\right)\right)\right)\right)\right) \]
    6. distribute-neg-fracN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(2, \left(\frac{\mathsf{neg}\left(\frac{1}{2}\right)}{{x}^{2}}\right)\right)\right)\right)\right)\right) \]
    7. metadata-evalN/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(2, \left(\frac{\frac{-1}{2}}{{x}^{2}}\right)\right)\right)\right)\right)\right) \]
    8. /-lowering-/.f64N/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(2, \mathsf{/.f64}\left(\frac{-1}{2}, \left({x}^{2}\right)\right)\right)\right)\right)\right)\right) \]
    9. unpow2N/A

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(2, \mathsf{/.f64}\left(\frac{-1}{2}, \left(x \cdot x\right)\right)\right)\right)\right)\right)\right) \]
    10. *-lowering-*.f6498.6%

      \[\leadsto \mathsf{neg.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(2, \mathsf{/.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, x\right)\right)\right)\right)\right)\right)\right) \]
  10. Simplified98.6%

    \[\leadsto -\log \left(\frac{1}{\color{blue}{x \cdot \left(2 + \frac{-0.5}{x \cdot x}\right)}}\right) \]
  11. Final simplification98.6%

    \[\leadsto 0 - \log \left(\frac{1}{x \cdot \left(2 + \frac{-0.5}{x \cdot x}\right)}\right) \]
  12. Add Preprocessing

Alternative 6: 99.5% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \log \left(x + \left(x + \frac{-0.5}{x}\right)\right) \end{array} \]
(FPCore (x) :precision binary64 (log (+ x (+ x (/ -0.5 x)))))
double code(double x) {
	return log((x + (x + (-0.5 / x))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((x + (x + ((-0.5d0) / x))))
end function
public static double code(double x) {
	return Math.log((x + (x + (-0.5 / x))));
}
def code(x):
	return math.log((x + (x + (-0.5 / x))))
function code(x)
	return log(Float64(x + Float64(x + Float64(-0.5 / x))))
end
function tmp = code(x)
	tmp = log((x + (x + (-0.5 / x))));
end
code[x_] := N[Log[N[(x + N[(x + N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\log \left(x + \left(x + \frac{-0.5}{x}\right)\right)
\end{array}
Derivation
  1. Initial program 48.5%

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

    \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{x}\right)\right) \]
  4. Step-by-step derivation
    1. Simplified97.8%

      \[\leadsto \log \left(x + \color{blue}{x}\right) \]
    2. Step-by-step derivation
      1. flip-+N/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{x \cdot x - x \cdot x}{x - x}\right)\right) \]
      2. +-inversesN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{0}{x - x}\right)\right) \]
      3. metadata-evalN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{0 + 0}{x - x}\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot 0 + 0}{x - x}\right)\right) \]
      5. +-inversesN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot \left(x - x\right) + 0}{x - x}\right)\right) \]
      6. +-inversesN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot \left(x - x\right) + \left(x \cdot x - x \cdot x\right)}{x - x}\right)\right) \]
      7. distribute-lft-out--N/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot \left(x - x\right) + x \cdot \left(x - x\right)}{x - x}\right)\right) \]
      8. +-inversesN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot \left(x - x\right) + x \cdot 0}{x - x}\right)\right) \]
      9. +-inversesN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot \left(x - x\right) + x \cdot \left(x \cdot x - x \cdot x\right)}{x - x}\right)\right) \]
      10. +-inversesN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot \left(x - x\right) + x \cdot \left(x \cdot x - x \cdot x\right)}{0}\right)\right) \]
      11. +-inversesN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot \left(x - x\right) + x \cdot \left(x \cdot x - x \cdot x\right)}{x \cdot x - x \cdot x}\right)\right) \]
      12. distribute-lft-out--N/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2} \cdot \left(x - x\right) + x \cdot \left(x \cdot x - x \cdot x\right)}{x \cdot \left(x - x\right)}\right)\right) \]
      13. frac-addN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\frac{\frac{-1}{2}}{x} + \frac{x \cdot x - x \cdot x}{x - x}\right)\right) \]
      14. *-lft-identityN/A

        \[\leadsto \mathsf{log.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + \frac{x \cdot x - x \cdot x}{x - x}\right)\right) \]
      15. flip-+N/A

        \[\leadsto \mathsf{log.f64}\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + \left(x + x\right)\right)\right) \]
      16. associate-+r+N/A

        \[\leadsto \mathsf{log.f64}\left(\left(\left(1 \cdot \frac{\frac{-1}{2}}{x} + x\right) + x\right)\right) \]
      17. +-commutativeN/A

        \[\leadsto \mathsf{log.f64}\left(\left(\left(x + 1 \cdot \frac{\frac{-1}{2}}{x}\right) + x\right)\right) \]
      18. +-lowering-+.f64N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\left(x + 1 \cdot \frac{\frac{-1}{2}}{x}\right), x\right)\right) \]
      19. +-lowering-+.f64N/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{+.f64}\left(x, \left(1 \cdot \frac{\frac{-1}{2}}{x}\right)\right), x\right)\right) \]
      20. *-lft-identityN/A

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{+.f64}\left(x, \left(\frac{\frac{-1}{2}}{x}\right)\right), x\right)\right) \]
      21. /-lowering-/.f6498.6%

        \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(\mathsf{+.f64}\left(x, \mathsf{/.f64}\left(\frac{-1}{2}, x\right)\right), x\right)\right) \]
    3. Applied egg-rr98.6%

      \[\leadsto \log \color{blue}{\left(\left(x + \frac{-0.5}{x}\right) + x\right)} \]
    4. Final simplification98.6%

      \[\leadsto \log \left(x + \left(x + \frac{-0.5}{x}\right)\right) \]
    5. Add Preprocessing

    Alternative 7: 99.0% accurate, 2.0× speedup?

    \[\begin{array}{l} \\ \log \left(x + x\right) \end{array} \]
    (FPCore (x) :precision binary64 (log (+ x x)))
    double code(double x) {
    	return log((x + x));
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = log((x + x))
    end function
    
    public static double code(double x) {
    	return Math.log((x + x));
    }
    
    def code(x):
    	return math.log((x + x))
    
    function code(x)
    	return log(Float64(x + x))
    end
    
    function tmp = code(x)
    	tmp = log((x + x));
    end
    
    code[x_] := N[Log[N[(x + x), $MachinePrecision]], $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \log \left(x + x\right)
    \end{array}
    
    Derivation
    1. Initial program 48.5%

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

      \[\leadsto \mathsf{log.f64}\left(\mathsf{+.f64}\left(x, \color{blue}{x}\right)\right) \]
    4. Step-by-step derivation
      1. Simplified97.8%

        \[\leadsto \log \left(x + \color{blue}{x}\right) \]
      2. Add Preprocessing

      Developer Target 1: 99.9% accurate, 0.7× speedup?

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

      Reproduce

      ?
      herbie shell --seed 2024138 
      (FPCore (x)
        :name "Rust f64::acosh"
        :precision binary64
        :pre (>= x 1.0)
      
        :alt
        (! :herbie-platform default (log (+ x (* (sqrt (- x 1)) (sqrt (+ x 1))))))
      
        (log (+ x (sqrt (- (* x x) 1.0)))))