invcot (example 3.9)

Percentage Accurate: 6.5% → 100.0%
Time: 12.6s
Alternatives: 5
Speedup: 35.7×

Specification

?
\[-0.026 < x \land x < 0.026\]
\[\begin{array}{l} \\ \frac{1}{x} - \frac{1}{\tan x} \end{array} \]
(FPCore (x) :precision binary64 (- (/ 1.0 x) (/ 1.0 (tan x))))
double code(double x) {
	return (1.0 / x) - (1.0 / tan(x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (1.0d0 / x) - (1.0d0 / tan(x))
end function
public static double code(double x) {
	return (1.0 / x) - (1.0 / Math.tan(x));
}
def code(x):
	return (1.0 / x) - (1.0 / math.tan(x))
function code(x)
	return Float64(Float64(1.0 / x) - Float64(1.0 / tan(x)))
end
function tmp = code(x)
	tmp = (1.0 / x) - (1.0 / tan(x));
end
code[x_] := N[(N[(1.0 / x), $MachinePrecision] - N[(1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{x} - \frac{1}{\tan 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 5 alternatives:

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

Initial Program: 6.5% accurate, 1.0× speedup?

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

\\
\frac{1}{x} - \frac{1}{\tan x}
\end{array}

Alternative 1: 100.0% accurate, 7.1× speedup?

\[\begin{array}{l} \\ \frac{x}{3 + x \cdot \left(x \cdot \left(-0.2 + \left(x \cdot x\right) \cdot -0.005714285714285714\right)\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ x (+ 3.0 (* x (* x (+ -0.2 (* (* x x) -0.005714285714285714)))))))
double code(double x) {
	return x / (3.0 + (x * (x * (-0.2 + ((x * x) * -0.005714285714285714)))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x / (3.0d0 + (x * (x * ((-0.2d0) + ((x * x) * (-0.005714285714285714d0))))))
end function
public static double code(double x) {
	return x / (3.0 + (x * (x * (-0.2 + ((x * x) * -0.005714285714285714)))));
}
def code(x):
	return x / (3.0 + (x * (x * (-0.2 + ((x * x) * -0.005714285714285714)))))
function code(x)
	return Float64(x / Float64(3.0 + Float64(x * Float64(x * Float64(-0.2 + Float64(Float64(x * x) * -0.005714285714285714))))))
end
function tmp = code(x)
	tmp = x / (3.0 + (x * (x * (-0.2 + ((x * x) * -0.005714285714285714)))));
end
code[x_] := N[(x / N[(3.0 + N[(x * N[(x * N[(-0.2 + N[(N[(x * x), $MachinePrecision] * -0.005714285714285714), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x}{3 + x \cdot \left(x \cdot \left(-0.2 + \left(x \cdot x\right) \cdot -0.005714285714285714\right)\right)}
\end{array}
Derivation
  1. Initial program 6.8%

    \[\frac{1}{x} - \frac{1}{\tan x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{x \cdot \left(\frac{1}{3} + {x}^{2} \cdot \left(\frac{1}{45} + \frac{2}{945} \cdot {x}^{2}\right)\right)} \]
  4. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{3} + {x}^{2} \cdot \left(\frac{1}{45} + \frac{2}{945} \cdot {x}^{2}\right)\right)}\right) \]
    2. +-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} + {x}^{2} \cdot \left(\frac{2}{945} \cdot {x}^{2} + \color{blue}{\frac{1}{45}}\right)\right)\right) \]
    3. distribute-lft-inN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} + \left({x}^{2} \cdot \left(\frac{2}{945} \cdot {x}^{2}\right) + \color{blue}{{x}^{2} \cdot \frac{1}{45}}\right)\right)\right) \]
    4. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} + \left({x}^{2} \cdot \left(\frac{2}{945} \cdot {x}^{2}\right) + \frac{1}{45} \cdot \color{blue}{{x}^{2}}\right)\right)\right) \]
    5. associate-+r+N/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\left(\frac{1}{3} + {x}^{2} \cdot \left(\frac{2}{945} \cdot {x}^{2}\right)\right) + \color{blue}{\frac{1}{45} \cdot {x}^{2}}\right)\right) \]
    6. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\left(\frac{1}{3} + \left(\frac{2}{945} \cdot {x}^{2}\right) \cdot {x}^{2}\right) + \frac{1}{45} \cdot {x}^{2}\right)\right) \]
    7. associate-*l*N/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\left(\frac{1}{3} + \frac{2}{945} \cdot \left({x}^{2} \cdot {x}^{2}\right)\right) + \frac{1}{45} \cdot {x}^{2}\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\left(\frac{1}{3} + \left(\mathsf{neg}\left(\frac{-2}{945}\right)\right) \cdot \left({x}^{2} \cdot {x}^{2}\right)\right) + \frac{1}{45} \cdot {x}^{2}\right)\right) \]
    9. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\left(\frac{1}{3} - \frac{-2}{945} \cdot \left({x}^{2} \cdot {x}^{2}\right)\right) + \color{blue}{\frac{1}{45}} \cdot {x}^{2}\right)\right) \]
    10. associate-*l*N/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\left(\frac{1}{3} - \left(\frac{-2}{945} \cdot {x}^{2}\right) \cdot {x}^{2}\right) + \frac{1}{45} \cdot {x}^{2}\right)\right) \]
    11. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\left(\frac{1}{3} - {x}^{2} \cdot \left(\frac{-2}{945} \cdot {x}^{2}\right)\right) + \frac{1}{45} \cdot {x}^{2}\right)\right) \]
    12. associate-+l-N/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} - \color{blue}{\left({x}^{2} \cdot \left(\frac{-2}{945} \cdot {x}^{2}\right) - \frac{1}{45} \cdot {x}^{2}\right)}\right)\right) \]
    13. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} - \left({x}^{2} \cdot \left(\frac{-2}{945} \cdot {x}^{2}\right) - {x}^{2} \cdot \color{blue}{\frac{1}{45}}\right)\right)\right) \]
    14. distribute-lft-out--N/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} - {x}^{2} \cdot \color{blue}{\left(\frac{-2}{945} \cdot {x}^{2} - \frac{1}{45}\right)}\right)\right) \]
    15. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \color{blue}{\left({x}^{2} \cdot \left(\frac{-2}{945} \cdot {x}^{2} - \frac{1}{45}\right)\right)}\right)\right) \]
  5. Simplified99.4%

    \[\leadsto \color{blue}{x \cdot \left(0.3333333333333333 - \left(x \cdot x\right) \cdot \left(-0.022222222222222223 + x \cdot \left(x \cdot -0.0021164021164021165\right)\right)\right)} \]
  6. Step-by-step derivation
    1. flip--N/A

      \[\leadsto x \cdot \frac{\frac{1}{3} \cdot \frac{1}{3} - \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right) \cdot \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right)}{\color{blue}{\frac{1}{3} + \left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)}} \]
    2. clear-numN/A

      \[\leadsto x \cdot \frac{1}{\color{blue}{\frac{\frac{1}{3} + \left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)}{\frac{1}{3} \cdot \frac{1}{3} - \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right) \cdot \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right)}}} \]
    3. un-div-invN/A

      \[\leadsto \frac{x}{\color{blue}{\frac{\frac{1}{3} + \left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)}{\frac{1}{3} \cdot \frac{1}{3} - \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right) \cdot \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right)}}} \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \color{blue}{\left(\frac{\frac{1}{3} + \left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)}{\frac{1}{3} \cdot \frac{1}{3} - \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right) \cdot \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right)}\right)}\right) \]
    5. clear-numN/A

      \[\leadsto \mathsf{/.f64}\left(x, \left(\frac{1}{\color{blue}{\frac{\frac{1}{3} \cdot \frac{1}{3} - \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right) \cdot \left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right)}{\frac{1}{3} + \left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)}}}\right)\right) \]
    6. flip--N/A

      \[\leadsto \mathsf{/.f64}\left(x, \left(\frac{1}{\frac{1}{3} - \color{blue}{\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)}}\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{1}{3} - \left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right)}\right)\right) \]
    8. --lowering--.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{\_.f64}\left(\frac{1}{3}, \color{blue}{\left(\left(x \cdot x\right) \cdot \left(\frac{-1}{45} + x \cdot \left(x \cdot \frac{-2}{945}\right)\right)\right)}\right)\right)\right) \]
  7. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\frac{x}{\frac{1}{0.3333333333333333 - \left(x \cdot x\right) \cdot \left(-0.022222222222222223 + \left(x \cdot x\right) \cdot -0.0021164021164021165\right)}}} \]
  8. Taylor expanded in x around 0

    \[\leadsto \mathsf{/.f64}\left(x, \color{blue}{\left(3 + {x}^{2} \cdot \left(\frac{-1}{175} \cdot {x}^{2} - \frac{1}{5}\right)\right)}\right) \]
  9. Step-by-step derivation
    1. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \color{blue}{\left({x}^{2} \cdot \left(\frac{-1}{175} \cdot {x}^{2} - \frac{1}{5}\right)\right)}\right)\right) \]
    2. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \left(\left(x \cdot x\right) \cdot \left(\color{blue}{\frac{-1}{175} \cdot {x}^{2}} - \frac{1}{5}\right)\right)\right)\right) \]
    3. associate-*l*N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \left(x \cdot \color{blue}{\left(x \cdot \left(\frac{-1}{175} \cdot {x}^{2} - \frac{1}{5}\right)\right)}\right)\right)\right) \]
    4. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \left(x \cdot \left(\left(\frac{-1}{175} \cdot {x}^{2} - \frac{1}{5}\right) \cdot \color{blue}{x}\right)\right)\right)\right) \]
    5. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \color{blue}{\left(\left(\frac{-1}{175} \cdot {x}^{2} - \frac{1}{5}\right) \cdot x\right)}\right)\right)\right) \]
    6. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\left(\frac{-1}{175} \cdot {x}^{2} - \frac{1}{5}\right)}\right)\right)\right)\right) \]
    7. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{-1}{175} \cdot {x}^{2} - \frac{1}{5}\right)}\right)\right)\right)\right) \]
    8. sub-negN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(\frac{-1}{175} \cdot {x}^{2} + \color{blue}{\left(\mathsf{neg}\left(\frac{1}{5}\right)\right)}\right)\right)\right)\right)\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(\frac{-1}{175} \cdot {x}^{2} + \frac{-1}{5}\right)\right)\right)\right)\right) \]
    10. +-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(\frac{-1}{5} + \color{blue}{\frac{-1}{175} \cdot {x}^{2}}\right)\right)\right)\right)\right) \]
    11. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{5}, \color{blue}{\left(\frac{-1}{175} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right) \]
    12. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{5}, \left({x}^{2} \cdot \color{blue}{\frac{-1}{175}}\right)\right)\right)\right)\right)\right) \]
    13. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{5}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{-1}{175}}\right)\right)\right)\right)\right)\right) \]
    14. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{5}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{-1}{175}\right)\right)\right)\right)\right)\right) \]
    15. *-lowering-*.f64100.0%

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-1}{5}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{-1}{175}\right)\right)\right)\right)\right)\right) \]
  10. Simplified100.0%

    \[\leadsto \frac{x}{\color{blue}{3 + x \cdot \left(x \cdot \left(-0.2 + \left(x \cdot x\right) \cdot -0.005714285714285714\right)\right)}} \]
  11. Add Preprocessing

Alternative 2: 99.9% accurate, 11.9× speedup?

\[\begin{array}{l} \\ \frac{x}{3 + -0.2 \cdot \left(x \cdot x\right)} \end{array} \]
(FPCore (x) :precision binary64 (/ x (+ 3.0 (* -0.2 (* x x)))))
double code(double x) {
	return x / (3.0 + (-0.2 * (x * x)));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x / (3.0d0 + ((-0.2d0) * (x * x)))
end function
public static double code(double x) {
	return x / (3.0 + (-0.2 * (x * x)));
}
def code(x):
	return x / (3.0 + (-0.2 * (x * x)))
function code(x)
	return Float64(x / Float64(3.0 + Float64(-0.2 * Float64(x * x))))
end
function tmp = code(x)
	tmp = x / (3.0 + (-0.2 * (x * x)));
end
code[x_] := N[(x / N[(3.0 + N[(-0.2 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x}{3 + -0.2 \cdot \left(x \cdot x\right)}
\end{array}
Derivation
  1. Initial program 6.8%

    \[\frac{1}{x} - \frac{1}{\tan x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{x \cdot \left(\frac{1}{3} + \frac{1}{45} \cdot {x}^{2}\right)} \]
  4. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{3} + \frac{1}{45} \cdot {x}^{2}\right)}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} + \left(\mathsf{neg}\left(\frac{-1}{45}\right)\right) \cdot {\color{blue}{x}}^{2}\right)\right) \]
    3. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} - \color{blue}{\frac{-1}{45} \cdot {x}^{2}}\right)\right) \]
    4. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \color{blue}{\left(\frac{-1}{45} \cdot {x}^{2}\right)}\right)\right) \]
    5. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \left({x}^{2} \cdot \color{blue}{\frac{-1}{45}}\right)\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{-1}{45}}\right)\right)\right) \]
    7. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{-1}{45}\right)\right)\right) \]
    8. *-lowering-*.f6499.2%

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{-1}{45}\right)\right)\right) \]
  5. Simplified99.2%

    \[\leadsto \color{blue}{x \cdot \left(0.3333333333333333 - \left(x \cdot x\right) \cdot -0.022222222222222223\right)} \]
  6. Step-by-step derivation
    1. flip3--N/A

      \[\leadsto x \cdot \frac{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}{\color{blue}{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}} \]
    2. clear-numN/A

      \[\leadsto x \cdot \frac{1}{\color{blue}{\frac{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}}} \]
    3. un-div-invN/A

      \[\leadsto \frac{x}{\color{blue}{\frac{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}}} \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \color{blue}{\left(\frac{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}\right)}\right) \]
    5. clear-numN/A

      \[\leadsto \mathsf{/.f64}\left(x, \left(\frac{1}{\color{blue}{\frac{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}}}\right)\right) \]
    6. flip3--N/A

      \[\leadsto \mathsf{/.f64}\left(x, \left(\frac{1}{\frac{1}{3} - \color{blue}{\left(x \cdot x\right) \cdot \frac{-1}{45}}}\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{1}{3} - \left(x \cdot x\right) \cdot \frac{-1}{45}\right)}\right)\right) \]
    8. sub-negN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \left(\frac{1}{3} + \color{blue}{\left(\mathsf{neg}\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}\right)\right)\right) \]
    9. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \color{blue}{\left(\mathsf{neg}\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}\right)\right)\right) \]
    10. distribute-rgt-neg-inN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{45}\right)\right)}\right)\right)\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\left(x \cdot x\right), \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{45}\right)\right)}\right)\right)\right)\right) \]
    12. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\mathsf{neg}\left(\color{blue}{\frac{-1}{45}}\right)\right)\right)\right)\right)\right) \]
    13. metadata-eval99.8%

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{45}\right)\right)\right)\right) \]
  7. Applied egg-rr99.8%

    \[\leadsto \color{blue}{\frac{x}{\frac{1}{0.3333333333333333 + \left(x \cdot x\right) \cdot 0.022222222222222223}}} \]
  8. Taylor expanded in x around 0

    \[\leadsto \mathsf{/.f64}\left(x, \color{blue}{\left(3 + \frac{-1}{5} \cdot {x}^{2}\right)}\right) \]
  9. Step-by-step derivation
    1. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \color{blue}{\left(\frac{-1}{5} \cdot {x}^{2}\right)}\right)\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \left({x}^{2} \cdot \color{blue}{\frac{-1}{5}}\right)\right)\right) \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{-1}{5}}\right)\right)\right) \]
    4. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{-1}{5}\right)\right)\right) \]
    5. *-lowering-*.f6499.8%

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(3, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{-1}{5}\right)\right)\right) \]
  10. Simplified99.8%

    \[\leadsto \frac{x}{\color{blue}{3 + \left(x \cdot x\right) \cdot -0.2}} \]
  11. Final simplification99.8%

    \[\leadsto \frac{x}{3 + -0.2 \cdot \left(x \cdot x\right)} \]
  12. Add Preprocessing

Alternative 3: 99.4% accurate, 11.9× speedup?

\[\begin{array}{l} \\ x \cdot \left(0.3333333333333333 - \left(x \cdot x\right) \cdot -0.022222222222222223\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (* x (- 0.3333333333333333 (* (* x x) -0.022222222222222223))))
double code(double x) {
	return x * (0.3333333333333333 - ((x * x) * -0.022222222222222223));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x * (0.3333333333333333d0 - ((x * x) * (-0.022222222222222223d0)))
end function
public static double code(double x) {
	return x * (0.3333333333333333 - ((x * x) * -0.022222222222222223));
}
def code(x):
	return x * (0.3333333333333333 - ((x * x) * -0.022222222222222223))
function code(x)
	return Float64(x * Float64(0.3333333333333333 - Float64(Float64(x * x) * -0.022222222222222223)))
end
function tmp = code(x)
	tmp = x * (0.3333333333333333 - ((x * x) * -0.022222222222222223));
end
code[x_] := N[(x * N[(0.3333333333333333 - N[(N[(x * x), $MachinePrecision] * -0.022222222222222223), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(0.3333333333333333 - \left(x \cdot x\right) \cdot -0.022222222222222223\right)
\end{array}
Derivation
  1. Initial program 6.8%

    \[\frac{1}{x} - \frac{1}{\tan x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{x \cdot \left(\frac{1}{3} + \frac{1}{45} \cdot {x}^{2}\right)} \]
  4. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{3} + \frac{1}{45} \cdot {x}^{2}\right)}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} + \left(\mathsf{neg}\left(\frac{-1}{45}\right)\right) \cdot {\color{blue}{x}}^{2}\right)\right) \]
    3. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} - \color{blue}{\frac{-1}{45} \cdot {x}^{2}}\right)\right) \]
    4. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \color{blue}{\left(\frac{-1}{45} \cdot {x}^{2}\right)}\right)\right) \]
    5. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \left({x}^{2} \cdot \color{blue}{\frac{-1}{45}}\right)\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{-1}{45}}\right)\right)\right) \]
    7. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{-1}{45}\right)\right)\right) \]
    8. *-lowering-*.f6499.2%

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{-1}{45}\right)\right)\right) \]
  5. Simplified99.2%

    \[\leadsto \color{blue}{x \cdot \left(0.3333333333333333 - \left(x \cdot x\right) \cdot -0.022222222222222223\right)} \]
  6. Add Preprocessing

Alternative 4: 99.4% accurate, 35.7× speedup?

\[\begin{array}{l} \\ \frac{x}{3} \end{array} \]
(FPCore (x) :precision binary64 (/ x 3.0))
double code(double x) {
	return x / 3.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x / 3.0d0
end function
public static double code(double x) {
	return x / 3.0;
}
def code(x):
	return x / 3.0
function code(x)
	return Float64(x / 3.0)
end
function tmp = code(x)
	tmp = x / 3.0;
end
code[x_] := N[(x / 3.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{x}{3}
\end{array}
Derivation
  1. Initial program 6.8%

    \[\frac{1}{x} - \frac{1}{\tan x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{x \cdot \left(\frac{1}{3} + \frac{1}{45} \cdot {x}^{2}\right)} \]
  4. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{3} + \frac{1}{45} \cdot {x}^{2}\right)}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} + \left(\mathsf{neg}\left(\frac{-1}{45}\right)\right) \cdot {\color{blue}{x}}^{2}\right)\right) \]
    3. cancel-sign-sub-invN/A

      \[\leadsto \mathsf{*.f64}\left(x, \left(\frac{1}{3} - \color{blue}{\frac{-1}{45} \cdot {x}^{2}}\right)\right) \]
    4. --lowering--.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \color{blue}{\left(\frac{-1}{45} \cdot {x}^{2}\right)}\right)\right) \]
    5. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \left({x}^{2} \cdot \color{blue}{\frac{-1}{45}}\right)\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{-1}{45}}\right)\right)\right) \]
    7. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{-1}{45}\right)\right)\right) \]
    8. *-lowering-*.f6499.2%

      \[\leadsto \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{-1}{45}\right)\right)\right) \]
  5. Simplified99.2%

    \[\leadsto \color{blue}{x \cdot \left(0.3333333333333333 - \left(x \cdot x\right) \cdot -0.022222222222222223\right)} \]
  6. Step-by-step derivation
    1. flip3--N/A

      \[\leadsto x \cdot \frac{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}{\color{blue}{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}} \]
    2. clear-numN/A

      \[\leadsto x \cdot \frac{1}{\color{blue}{\frac{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}}} \]
    3. un-div-invN/A

      \[\leadsto \frac{x}{\color{blue}{\frac{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}}} \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \color{blue}{\left(\frac{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}\right)}\right) \]
    5. clear-numN/A

      \[\leadsto \mathsf{/.f64}\left(x, \left(\frac{1}{\color{blue}{\frac{{\frac{1}{3}}^{3} - {\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)}^{3}}{\frac{1}{3} \cdot \frac{1}{3} + \left(\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right) + \frac{1}{3} \cdot \left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}}}\right)\right) \]
    6. flip3--N/A

      \[\leadsto \mathsf{/.f64}\left(x, \left(\frac{1}{\frac{1}{3} - \color{blue}{\left(x \cdot x\right) \cdot \frac{-1}{45}}}\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{1}{3} - \left(x \cdot x\right) \cdot \frac{-1}{45}\right)}\right)\right) \]
    8. sub-negN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \left(\frac{1}{3} + \color{blue}{\left(\mathsf{neg}\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}\right)\right)\right) \]
    9. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \color{blue}{\left(\mathsf{neg}\left(\left(x \cdot x\right) \cdot \frac{-1}{45}\right)\right)}\right)\right)\right) \]
    10. distribute-rgt-neg-inN/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{45}\right)\right)}\right)\right)\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\left(x \cdot x\right), \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{45}\right)\right)}\right)\right)\right)\right) \]
    12. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\mathsf{neg}\left(\color{blue}{\frac{-1}{45}}\right)\right)\right)\right)\right)\right) \]
    13. metadata-eval99.8%

      \[\leadsto \mathsf{/.f64}\left(x, \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\frac{1}{3}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{45}\right)\right)\right)\right) \]
  7. Applied egg-rr99.8%

    \[\leadsto \color{blue}{\frac{x}{\frac{1}{0.3333333333333333 + \left(x \cdot x\right) \cdot 0.022222222222222223}}} \]
  8. Taylor expanded in x around 0

    \[\leadsto \mathsf{/.f64}\left(x, \color{blue}{3}\right) \]
  9. Step-by-step derivation
    1. Simplified99.1%

      \[\leadsto \frac{x}{\color{blue}{3}} \]
    2. Add Preprocessing

    Alternative 5: 98.9% accurate, 35.7× speedup?

    \[\begin{array}{l} \\ x \cdot 0.3333333333333333 \end{array} \]
    (FPCore (x) :precision binary64 (* x 0.3333333333333333))
    double code(double x) {
    	return x * 0.3333333333333333;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = x * 0.3333333333333333d0
    end function
    
    public static double code(double x) {
    	return x * 0.3333333333333333;
    }
    
    def code(x):
    	return x * 0.3333333333333333
    
    function code(x)
    	return Float64(x * 0.3333333333333333)
    end
    
    function tmp = code(x)
    	tmp = x * 0.3333333333333333;
    end
    
    code[x_] := N[(x * 0.3333333333333333), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    x \cdot 0.3333333333333333
    \end{array}
    
    Derivation
    1. Initial program 6.8%

      \[\frac{1}{x} - \frac{1}{\tan x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{1}{3} \cdot x} \]
    4. Step-by-step derivation
      1. *-lowering-*.f6498.5%

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \color{blue}{x}\right) \]
    5. Simplified98.5%

      \[\leadsto \color{blue}{0.3333333333333333 \cdot x} \]
    6. Final simplification98.5%

      \[\leadsto x \cdot 0.3333333333333333 \]
    7. Add Preprocessing

    Developer Target 1: 99.9% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left|x\right| < 0.026:\\ \;\;\;\;\frac{x}{3} \cdot \left(1 + \frac{x \cdot x}{15}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x} - \frac{1}{\tan x}\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (< (fabs x) 0.026)
       (* (/ x 3.0) (+ 1.0 (/ (* x x) 15.0)))
       (- (/ 1.0 x) (/ 1.0 (tan x)))))
    double code(double x) {
    	double tmp;
    	if (fabs(x) < 0.026) {
    		tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0));
    	} else {
    		tmp = (1.0 / x) - (1.0 / tan(x));
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if (abs(x) < 0.026d0) then
            tmp = (x / 3.0d0) * (1.0d0 + ((x * x) / 15.0d0))
        else
            tmp = (1.0d0 / x) - (1.0d0 / tan(x))
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if (Math.abs(x) < 0.026) {
    		tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0));
    	} else {
    		tmp = (1.0 / x) - (1.0 / Math.tan(x));
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if math.fabs(x) < 0.026:
    		tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0))
    	else:
    		tmp = (1.0 / x) - (1.0 / math.tan(x))
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (abs(x) < 0.026)
    		tmp = Float64(Float64(x / 3.0) * Float64(1.0 + Float64(Float64(x * x) / 15.0)));
    	else
    		tmp = Float64(Float64(1.0 / x) - Float64(1.0 / tan(x)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if (abs(x) < 0.026)
    		tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0));
    	else
    		tmp = (1.0 / x) - (1.0 / tan(x));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[Less[N[Abs[x], $MachinePrecision], 0.026], N[(N[(x / 3.0), $MachinePrecision] * N[(1.0 + N[(N[(x * x), $MachinePrecision] / 15.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / x), $MachinePrecision] - N[(1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\left|x\right| < 0.026:\\
    \;\;\;\;\frac{x}{3} \cdot \left(1 + \frac{x \cdot x}{15}\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{1}{x} - \frac{1}{\tan x}\\
    
    
    \end{array}
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2024155 
    (FPCore (x)
      :name "invcot (example 3.9)"
      :precision binary64
      :pre (and (< -0.026 x) (< x 0.026))
    
      :alt
      (! :herbie-platform default (if (< (fabs x) 13/500) (* (/ x 3) (+ 1 (/ (* x x) 15))) (- (/ 1 x) (/ 1 (tan x)))))
    
      (- (/ 1.0 x) (/ 1.0 (tan x))))