Rust f64::acosh

Percentage Accurate: 50.6% → 99.6%
Time: 4.9s
Alternatives: 12
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 12 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: 50.6% 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: 99.6% 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 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.3%

    \[\leadsto \log \left(x + \color{blue}{\left(x - 0.5 \cdot \frac{1}{x}\right)}\right) \]
  3. Step-by-step derivation
    1. associate-*r/99.3%

      \[\leadsto \log \left(x + \left(x - \color{blue}{\frac{0.5 \cdot 1}{x}}\right)\right) \]
    2. metadata-eval99.3%

      \[\leadsto \log \left(x + \left(x - \frac{\color{blue}{0.5}}{x}\right)\right) \]
  4. Simplified99.3%

    \[\leadsto \log \left(x + \color{blue}{\left(x - \frac{0.5}{x}\right)}\right) \]
  5. Final simplification99.3%

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

Alternative 2: 99.2% 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 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Final simplification99.0%

    \[\leadsto \log \left(x + x\right) \]

Alternative 3: 1.6% accurate, 207.0× speedup?

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

\\
-1
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Applied egg-rr0.0%

    \[\leadsto \color{blue}{\log \left(\frac{0}{0}\right) + \log \left(\frac{0}{0}\right)} \]
  4. Simplified1.6%

    \[\leadsto \color{blue}{-1} \]
  5. Final simplification1.6%

    \[\leadsto -1 \]

Alternative 4: 13.9% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 0.6666666666666666 \end{array} \]
(FPCore (x) :precision binary64 0.6666666666666666)
double code(double x) {
	return 0.6666666666666666;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.6666666666666666d0
end function
public static double code(double x) {
	return 0.6666666666666666;
}
def code(x):
	return 0.6666666666666666
function code(x)
	return 0.6666666666666666
end
function tmp = code(x)
	tmp = 0.6666666666666666;
end
code[x_] := 0.6666666666666666
\begin{array}{l}

\\
0.6666666666666666
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr14.0%

    \[\leadsto \color{blue}{0.6666666666666666} \]
  7. Final simplification14.0%

    \[\leadsto 0.6666666666666666 \]

Alternative 5: 15.0% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 6 \end{array} \]
(FPCore (x) :precision binary64 6.0)
double code(double x) {
	return 6.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 6.0d0
end function
public static double code(double x) {
	return 6.0;
}
def code(x):
	return 6.0
function code(x)
	return 6.0
end
function tmp = code(x)
	tmp = 6.0;
end
code[x_] := 6.0
\begin{array}{l}

\\
6
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr15.1%

    \[\leadsto \color{blue}{6} \]
  7. Final simplification15.1%

    \[\leadsto 6 \]

Alternative 6: 15.3% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 9 \end{array} \]
(FPCore (x) :precision binary64 9.0)
double code(double x) {
	return 9.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 9.0d0
end function
public static double code(double x) {
	return 9.0;
}
def code(x):
	return 9.0
function code(x)
	return 9.0
end
function tmp = code(x)
	tmp = 9.0;
end
code[x_] := 9.0
\begin{array}{l}

\\
9
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr15.4%

    \[\leadsto \color{blue}{9} \]
  7. Final simplification15.4%

    \[\leadsto 9 \]

Alternative 7: 15.8% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 16 \end{array} \]
(FPCore (x) :precision binary64 16.0)
double code(double x) {
	return 16.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 16.0d0
end function
public static double code(double x) {
	return 16.0;
}
def code(x):
	return 16.0
function code(x)
	return 16.0
end
function tmp = code(x)
	tmp = 16.0;
end
code[x_] := 16.0
\begin{array}{l}

\\
16
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr15.9%

    \[\leadsto \color{blue}{16} \]
  7. Final simplification15.9%

    \[\leadsto 16 \]

Alternative 8: 15.9% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 17 \end{array} \]
(FPCore (x) :precision binary64 17.0)
double code(double x) {
	return 17.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 17.0d0
end function
public static double code(double x) {
	return 17.0;
}
def code(x):
	return 17.0
function code(x)
	return 17.0
end
function tmp = code(x)
	tmp = 17.0;
end
code[x_] := 17.0
\begin{array}{l}

\\
17
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr15.9%

    \[\leadsto \color{blue}{17} \]
  7. Final simplification15.9%

    \[\leadsto 17 \]

Alternative 9: 16.3% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 27 \end{array} \]
(FPCore (x) :precision binary64 27.0)
double code(double x) {
	return 27.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 27.0d0
end function
public static double code(double x) {
	return 27.0;
}
def code(x):
	return 27.0
function code(x)
	return 27.0
end
function tmp = code(x)
	tmp = 27.0;
end
code[x_] := 27.0
\begin{array}{l}

\\
27
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr16.4%

    \[\leadsto \color{blue}{27} \]
  7. Final simplification16.4%

    \[\leadsto 27 \]

Alternative 10: 17.4% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 64 \end{array} \]
(FPCore (x) :precision binary64 64.0)
double code(double x) {
	return 64.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 64.0d0
end function
public static double code(double x) {
	return 64.0;
}
def code(x):
	return 64.0
function code(x)
	return 64.0
end
function tmp = code(x)
	tmp = 64.0;
end
code[x_] := 64.0
\begin{array}{l}

\\
64
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr17.5%

    \[\leadsto \color{blue}{64} \]
  7. Final simplification17.5%

    \[\leadsto 64 \]

Alternative 11: 17.4% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 65 \end{array} \]
(FPCore (x) :precision binary64 65.0)
double code(double x) {
	return 65.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 65.0d0
end function
public static double code(double x) {
	return 65.0;
}
def code(x):
	return 65.0
function code(x)
	return 65.0
end
function tmp = code(x)
	tmp = 65.0;
end
code[x_] := 65.0
\begin{array}{l}

\\
65
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr17.6%

    \[\leadsto \color{blue}{65} \]
  7. Final simplification17.6%

    \[\leadsto 65 \]

Alternative 12: 19.5% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 256 \end{array} \]
(FPCore (x) :precision binary64 256.0)
double code(double x) {
	return 256.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 256.0d0
end function
public static double code(double x) {
	return 256.0;
}
def code(x):
	return 256.0
function code(x)
	return 256.0
end
function tmp = code(x)
	tmp = 256.0;
end
code[x_] := 256.0
\begin{array}{l}

\\
256
\end{array}
Derivation
  1. Initial program 59.1%

    \[\log \left(x + \sqrt{x \cdot x - 1}\right) \]
  2. Taylor expanded in x around inf 99.0%

    \[\leadsto \log \left(x + \color{blue}{x}\right) \]
  3. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \log \color{blue}{\left(\frac{x \cdot x - x \cdot x}{x - x}\right)} \]
    2. difference-of-squares0.0%

      \[\leadsto \log \left(\frac{\color{blue}{\left(x + x\right) \cdot \left(x - x\right)}}{x - x}\right) \]
    3. associate-*r/0.0%

      \[\leadsto \log \color{blue}{\left(\left(x + x\right) \cdot \frac{x - x}{x - x}\right)} \]
    4. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{0}}{x - x}\right) \]
    5. +-inverses0.0%

      \[\leadsto \log \left(\left(x + x\right) \cdot \frac{\color{blue}{x \cdot x - x \cdot x}}{x - x}\right) \]
    6. flip-+12.1%

      \[\leadsto \log \left(\left(x + x\right) \cdot \color{blue}{\left(x + x\right)}\right) \]
    7. count-212.1%

      \[\leadsto \log \left(\color{blue}{\left(2 \cdot x\right)} \cdot \left(x + x\right)\right) \]
    8. count-212.1%

      \[\leadsto \log \left(\left(2 \cdot x\right) \cdot \color{blue}{\left(2 \cdot x\right)}\right) \]
    9. swap-sqr12.1%

      \[\leadsto \log \color{blue}{\left(\left(2 \cdot 2\right) \cdot \left(x \cdot x\right)\right)} \]
    10. log-prod12.2%

      \[\leadsto \color{blue}{\log \left(2 \cdot 2\right) + \log \left(x \cdot x\right)} \]
    11. metadata-eval12.2%

      \[\leadsto \log \color{blue}{4} + \log \left(x \cdot x\right) \]
  4. Applied egg-rr12.2%

    \[\leadsto \color{blue}{\log 4 + \log \left(x \cdot x\right)} \]
  5. Simplified13.8%

    \[\leadsto \color{blue}{-1 + \log 4} \]
  6. Applied egg-rr19.6%

    \[\leadsto \color{blue}{256} \]
  7. Final simplification19.6%

    \[\leadsto 256 \]

Developer target: 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 2023275 
(FPCore (x)
  :name "Rust f64::acosh"
  :precision binary64
  :pre (>= x 1.0)

  :herbie-target
  (log (+ x (* (sqrt (- x 1.0)) (sqrt (+ x 1.0)))))

  (log (+ x (sqrt (- (* x x) 1.0)))))