Octave 3.8, jcobi/4, as called

Percentage Accurate: 27.6% → 100.0%
Time: 4.6s
Alternatives: 5
Speedup: 25.0×

Specification

?
\[i > 0\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\\ \frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{t\_0}}{t\_0 - 1} \end{array} \end{array} \]
(FPCore (i)
 :precision binary64
 (let* ((t_0 (* (* 2.0 i) (* 2.0 i))))
   (/ (/ (* (* i i) (* i i)) t_0) (- t_0 1.0))))
double code(double i) {
	double t_0 = (2.0 * i) * (2.0 * i);
	return (((i * i) * (i * i)) / t_0) / (t_0 - 1.0);
}
real(8) function code(i)
    real(8), intent (in) :: i
    real(8) :: t_0
    t_0 = (2.0d0 * i) * (2.0d0 * i)
    code = (((i * i) * (i * i)) / t_0) / (t_0 - 1.0d0)
end function
public static double code(double i) {
	double t_0 = (2.0 * i) * (2.0 * i);
	return (((i * i) * (i * i)) / t_0) / (t_0 - 1.0);
}
def code(i):
	t_0 = (2.0 * i) * (2.0 * i)
	return (((i * i) * (i * i)) / t_0) / (t_0 - 1.0)
function code(i)
	t_0 = Float64(Float64(2.0 * i) * Float64(2.0 * i))
	return Float64(Float64(Float64(Float64(i * i) * Float64(i * i)) / t_0) / Float64(t_0 - 1.0))
end
function tmp = code(i)
	t_0 = (2.0 * i) * (2.0 * i);
	tmp = (((i * i) * (i * i)) / t_0) / (t_0 - 1.0);
end
code[i_] := Block[{t$95$0 = N[(N[(2.0 * i), $MachinePrecision] * N[(2.0 * i), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(i * i), $MachinePrecision] * N[(i * i), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] / N[(t$95$0 - 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\\
\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{t\_0}}{t\_0 - 1}
\end{array}
\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: 27.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\\ \frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{t\_0}}{t\_0 - 1} \end{array} \end{array} \]
(FPCore (i)
 :precision binary64
 (let* ((t_0 (* (* 2.0 i) (* 2.0 i))))
   (/ (/ (* (* i i) (* i i)) t_0) (- t_0 1.0))))
double code(double i) {
	double t_0 = (2.0 * i) * (2.0 * i);
	return (((i * i) * (i * i)) / t_0) / (t_0 - 1.0);
}
real(8) function code(i)
    real(8), intent (in) :: i
    real(8) :: t_0
    t_0 = (2.0d0 * i) * (2.0d0 * i)
    code = (((i * i) * (i * i)) / t_0) / (t_0 - 1.0d0)
end function
public static double code(double i) {
	double t_0 = (2.0 * i) * (2.0 * i);
	return (((i * i) * (i * i)) / t_0) / (t_0 - 1.0);
}
def code(i):
	t_0 = (2.0 * i) * (2.0 * i)
	return (((i * i) * (i * i)) / t_0) / (t_0 - 1.0)
function code(i)
	t_0 = Float64(Float64(2.0 * i) * Float64(2.0 * i))
	return Float64(Float64(Float64(Float64(i * i) * Float64(i * i)) / t_0) / Float64(t_0 - 1.0))
end
function tmp = code(i)
	t_0 = (2.0 * i) * (2.0 * i);
	tmp = (((i * i) * (i * i)) / t_0) / (t_0 - 1.0);
end
code[i_] := Block[{t$95$0 = N[(N[(2.0 * i), $MachinePrecision] * N[(2.0 * i), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(i * i), $MachinePrecision] * N[(i * i), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] / N[(t$95$0 - 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\\
\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{t\_0}}{t\_0 - 1}
\end{array}
\end{array}

Alternative 1: 100.0% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;i \leq 40000000:\\ \;\;\;\;i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}\\ \mathbf{else}:\\ \;\;\;\;0.0625\\ \end{array} \end{array} \]
(FPCore (i)
 :precision binary64
 (if (<= i 40000000.0) (* i (/ i (+ (* (* i i) 16.0) -4.0))) 0.0625))
double code(double i) {
	double tmp;
	if (i <= 40000000.0) {
		tmp = i * (i / (((i * i) * 16.0) + -4.0));
	} else {
		tmp = 0.0625;
	}
	return tmp;
}
real(8) function code(i)
    real(8), intent (in) :: i
    real(8) :: tmp
    if (i <= 40000000.0d0) then
        tmp = i * (i / (((i * i) * 16.0d0) + (-4.0d0)))
    else
        tmp = 0.0625d0
    end if
    code = tmp
end function
public static double code(double i) {
	double tmp;
	if (i <= 40000000.0) {
		tmp = i * (i / (((i * i) * 16.0) + -4.0));
	} else {
		tmp = 0.0625;
	}
	return tmp;
}
def code(i):
	tmp = 0
	if i <= 40000000.0:
		tmp = i * (i / (((i * i) * 16.0) + -4.0))
	else:
		tmp = 0.0625
	return tmp
function code(i)
	tmp = 0.0
	if (i <= 40000000.0)
		tmp = Float64(i * Float64(i / Float64(Float64(Float64(i * i) * 16.0) + -4.0)));
	else
		tmp = 0.0625;
	end
	return tmp
end
function tmp_2 = code(i)
	tmp = 0.0;
	if (i <= 40000000.0)
		tmp = i * (i / (((i * i) * 16.0) + -4.0));
	else
		tmp = 0.0625;
	end
	tmp_2 = tmp;
end
code[i_] := If[LessEqual[i, 40000000.0], N[(i * N[(i / N[(N[(N[(i * i), $MachinePrecision] * 16.0), $MachinePrecision] + -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.0625]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;i \leq 40000000:\\
\;\;\;\;i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}\\

\mathbf{else}:\\
\;\;\;\;0.0625\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if i < 4e7

    1. Initial program 30.8%

      \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
    2. Step-by-step derivation
      1. associate-/l/N/A

        \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
      2. associate-*l*N/A

        \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
      3. associate-/l*N/A

        \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
      5. swap-sqrN/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
      6. associate-*r*N/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
      7. times-fracN/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
      8. *-inversesN/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
      9. *-rgt-identityN/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
      10. /-lowering-/.f64N/A

        \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
      11. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
    4. Add Preprocessing

    if 4e7 < i

    1. Initial program 20.4%

      \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
    2. Step-by-step derivation
      1. associate-/l/N/A

        \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
      2. associate-*l*N/A

        \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
      3. associate-/l*N/A

        \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
      5. swap-sqrN/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
      6. associate-*r*N/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
      7. times-fracN/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
      8. *-inversesN/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
      9. *-rgt-identityN/A

        \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
      10. /-lowering-/.f64N/A

        \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
      11. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
    3. Simplified41.4%

      \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
    4. Add Preprocessing
    5. Taylor expanded in i around inf

      \[\leadsto \color{blue}{\frac{1}{16}} \]
    6. Step-by-step derivation
      1. Simplified100.0%

        \[\leadsto \color{blue}{0.0625} \]
    7. Recombined 2 regimes into one program.
    8. Add Preprocessing

    Alternative 2: 99.4% accurate, 1.8× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;i \leq 0.5:\\ \;\;\;\;\left(i \cdot i\right) \cdot \left(-0.25 - i \cdot i\right)\\ \mathbf{else}:\\ \;\;\;\;0.0625 + \frac{0.015625}{i \cdot i}\\ \end{array} \end{array} \]
    (FPCore (i)
     :precision binary64
     (if (<= i 0.5) (* (* i i) (- -0.25 (* i i))) (+ 0.0625 (/ 0.015625 (* i i)))))
    double code(double i) {
    	double tmp;
    	if (i <= 0.5) {
    		tmp = (i * i) * (-0.25 - (i * i));
    	} else {
    		tmp = 0.0625 + (0.015625 / (i * i));
    	}
    	return tmp;
    }
    
    real(8) function code(i)
        real(8), intent (in) :: i
        real(8) :: tmp
        if (i <= 0.5d0) then
            tmp = (i * i) * ((-0.25d0) - (i * i))
        else
            tmp = 0.0625d0 + (0.015625d0 / (i * i))
        end if
        code = tmp
    end function
    
    public static double code(double i) {
    	double tmp;
    	if (i <= 0.5) {
    		tmp = (i * i) * (-0.25 - (i * i));
    	} else {
    		tmp = 0.0625 + (0.015625 / (i * i));
    	}
    	return tmp;
    }
    
    def code(i):
    	tmp = 0
    	if i <= 0.5:
    		tmp = (i * i) * (-0.25 - (i * i))
    	else:
    		tmp = 0.0625 + (0.015625 / (i * i))
    	return tmp
    
    function code(i)
    	tmp = 0.0
    	if (i <= 0.5)
    		tmp = Float64(Float64(i * i) * Float64(-0.25 - Float64(i * i)));
    	else
    		tmp = Float64(0.0625 + Float64(0.015625 / Float64(i * i)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(i)
    	tmp = 0.0;
    	if (i <= 0.5)
    		tmp = (i * i) * (-0.25 - (i * i));
    	else
    		tmp = 0.0625 + (0.015625 / (i * i));
    	end
    	tmp_2 = tmp;
    end
    
    code[i_] := If[LessEqual[i, 0.5], N[(N[(i * i), $MachinePrecision] * N[(-0.25 - N[(i * i), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.0625 + N[(0.015625 / N[(i * i), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;i \leq 0.5:\\
    \;\;\;\;\left(i \cdot i\right) \cdot \left(-0.25 - i \cdot i\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;0.0625 + \frac{0.015625}{i \cdot i}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if i < 0.5

      1. Initial program 29.7%

        \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
      2. Step-by-step derivation
        1. associate-/l/N/A

          \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
        2. associate-*l*N/A

          \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
        3. associate-/l*N/A

          \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
        4. *-lowering-*.f64N/A

          \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
        5. swap-sqrN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
        6. associate-*r*N/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
        7. times-fracN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
        8. *-inversesN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
        9. *-rgt-identityN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
        10. /-lowering-/.f64N/A

          \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
        11. *-commutativeN/A

          \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
      4. Add Preprocessing
      5. Taylor expanded in i around 0

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

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

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

          \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(i, i\right), \left(\color{blue}{-1 \cdot {i}^{2}} - \frac{1}{4}\right)\right) \]
        4. sub-negN/A

          \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(i, i\right), \left(-1 \cdot {i}^{2} + \color{blue}{\left(\mathsf{neg}\left(\frac{1}{4}\right)\right)}\right)\right) \]
        5. metadata-evalN/A

          \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(i, i\right), \left(-1 \cdot {i}^{2} + \frac{-1}{4}\right)\right) \]
        6. +-commutativeN/A

          \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(i, i\right), \left(\frac{-1}{4} + \color{blue}{-1 \cdot {i}^{2}}\right)\right) \]
        7. mul-1-negN/A

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

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

          \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(i, i\right), \mathsf{\_.f64}\left(\frac{-1}{4}, \color{blue}{\left({i}^{2}\right)}\right)\right) \]
        10. unpow2N/A

          \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(i, i\right), \mathsf{\_.f64}\left(\frac{-1}{4}, \left(i \cdot \color{blue}{i}\right)\right)\right) \]
        11. *-lowering-*.f6499.9%

          \[\leadsto \mathsf{*.f64}\left(\mathsf{*.f64}\left(i, i\right), \mathsf{\_.f64}\left(\frac{-1}{4}, \mathsf{*.f64}\left(i, \color{blue}{i}\right)\right)\right) \]
      7. Simplified99.9%

        \[\leadsto \color{blue}{\left(i \cdot i\right) \cdot \left(-0.25 - i \cdot i\right)} \]

      if 0.5 < i

      1. Initial program 21.6%

        \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
      2. Step-by-step derivation
        1. associate-/l/N/A

          \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
        2. associate-*l*N/A

          \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
        3. associate-/l*N/A

          \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
        4. *-lowering-*.f64N/A

          \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
        5. swap-sqrN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
        6. associate-*r*N/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
        7. times-fracN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
        8. *-inversesN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
        9. *-rgt-identityN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
        10. /-lowering-/.f64N/A

          \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
        11. *-commutativeN/A

          \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
      3. Simplified42.3%

        \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
      4. Add Preprocessing
      5. Taylor expanded in i around inf

        \[\leadsto \color{blue}{\frac{1}{16} + \frac{1}{64} \cdot \frac{1}{{i}^{2}}} \]
      6. Step-by-step derivation
        1. +-lowering-+.f64N/A

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \color{blue}{\left(\frac{1}{64} \cdot \frac{1}{{i}^{2}}\right)}\right) \]
        2. associate-*r/N/A

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \left(\frac{\frac{1}{64} \cdot 1}{\color{blue}{{i}^{2}}}\right)\right) \]
        3. metadata-evalN/A

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \left(\frac{\frac{1}{64}}{{\color{blue}{i}}^{2}}\right)\right) \]
        4. /-lowering-/.f64N/A

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \mathsf{/.f64}\left(\frac{1}{64}, \color{blue}{\left({i}^{2}\right)}\right)\right) \]
        5. unpow2N/A

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \mathsf{/.f64}\left(\frac{1}{64}, \left(i \cdot \color{blue}{i}\right)\right)\right) \]
        6. *-lowering-*.f6499.4%

          \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \mathsf{/.f64}\left(\frac{1}{64}, \mathsf{*.f64}\left(i, \color{blue}{i}\right)\right)\right) \]
      7. Simplified99.4%

        \[\leadsto \color{blue}{0.0625 + \frac{0.015625}{i \cdot i}} \]
    3. Recombined 2 regimes into one program.
    4. Add Preprocessing

    Alternative 3: 99.2% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;i \leq 0.5:\\ \;\;\;\;i \cdot \frac{i}{-4}\\ \mathbf{else}:\\ \;\;\;\;0.0625 + \frac{0.015625}{i \cdot i}\\ \end{array} \end{array} \]
    (FPCore (i)
     :precision binary64
     (if (<= i 0.5) (* i (/ i -4.0)) (+ 0.0625 (/ 0.015625 (* i i)))))
    double code(double i) {
    	double tmp;
    	if (i <= 0.5) {
    		tmp = i * (i / -4.0);
    	} else {
    		tmp = 0.0625 + (0.015625 / (i * i));
    	}
    	return tmp;
    }
    
    real(8) function code(i)
        real(8), intent (in) :: i
        real(8) :: tmp
        if (i <= 0.5d0) then
            tmp = i * (i / (-4.0d0))
        else
            tmp = 0.0625d0 + (0.015625d0 / (i * i))
        end if
        code = tmp
    end function
    
    public static double code(double i) {
    	double tmp;
    	if (i <= 0.5) {
    		tmp = i * (i / -4.0);
    	} else {
    		tmp = 0.0625 + (0.015625 / (i * i));
    	}
    	return tmp;
    }
    
    def code(i):
    	tmp = 0
    	if i <= 0.5:
    		tmp = i * (i / -4.0)
    	else:
    		tmp = 0.0625 + (0.015625 / (i * i))
    	return tmp
    
    function code(i)
    	tmp = 0.0
    	if (i <= 0.5)
    		tmp = Float64(i * Float64(i / -4.0));
    	else
    		tmp = Float64(0.0625 + Float64(0.015625 / Float64(i * i)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(i)
    	tmp = 0.0;
    	if (i <= 0.5)
    		tmp = i * (i / -4.0);
    	else
    		tmp = 0.0625 + (0.015625 / (i * i));
    	end
    	tmp_2 = tmp;
    end
    
    code[i_] := If[LessEqual[i, 0.5], N[(i * N[(i / -4.0), $MachinePrecision]), $MachinePrecision], N[(0.0625 + N[(0.015625 / N[(i * i), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;i \leq 0.5:\\
    \;\;\;\;i \cdot \frac{i}{-4}\\
    
    \mathbf{else}:\\
    \;\;\;\;0.0625 + \frac{0.015625}{i \cdot i}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if i < 0.5

      1. Initial program 29.7%

        \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
      2. Step-by-step derivation
        1. associate-/l/N/A

          \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
        2. associate-*l*N/A

          \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
        3. associate-/l*N/A

          \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
        4. *-lowering-*.f64N/A

          \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
        5. swap-sqrN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
        6. associate-*r*N/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
        7. times-fracN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
        8. *-inversesN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
        9. *-rgt-identityN/A

          \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
        10. /-lowering-/.f64N/A

          \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
        11. *-commutativeN/A

          \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
      4. Add Preprocessing
      5. Taylor expanded in i around 0

        \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{-4}\right)\right) \]
      6. Step-by-step derivation
        1. Simplified99.5%

          \[\leadsto i \cdot \frac{i}{\color{blue}{-4}} \]

        if 0.5 < i

        1. Initial program 21.6%

          \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
        2. Step-by-step derivation
          1. associate-/l/N/A

            \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
          2. associate-*l*N/A

            \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
          3. associate-/l*N/A

            \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
          4. *-lowering-*.f64N/A

            \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
          5. swap-sqrN/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
          6. associate-*r*N/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
          7. times-fracN/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
          8. *-inversesN/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
          9. *-rgt-identityN/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
          10. /-lowering-/.f64N/A

            \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
          11. *-commutativeN/A

            \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
        3. Simplified42.3%

          \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
        4. Add Preprocessing
        5. Taylor expanded in i around inf

          \[\leadsto \color{blue}{\frac{1}{16} + \frac{1}{64} \cdot \frac{1}{{i}^{2}}} \]
        6. Step-by-step derivation
          1. +-lowering-+.f64N/A

            \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \color{blue}{\left(\frac{1}{64} \cdot \frac{1}{{i}^{2}}\right)}\right) \]
          2. associate-*r/N/A

            \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \left(\frac{\frac{1}{64} \cdot 1}{\color{blue}{{i}^{2}}}\right)\right) \]
          3. metadata-evalN/A

            \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \left(\frac{\frac{1}{64}}{{\color{blue}{i}}^{2}}\right)\right) \]
          4. /-lowering-/.f64N/A

            \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \mathsf{/.f64}\left(\frac{1}{64}, \color{blue}{\left({i}^{2}\right)}\right)\right) \]
          5. unpow2N/A

            \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \mathsf{/.f64}\left(\frac{1}{64}, \left(i \cdot \color{blue}{i}\right)\right)\right) \]
          6. *-lowering-*.f6499.4%

            \[\leadsto \mathsf{+.f64}\left(\frac{1}{16}, \mathsf{/.f64}\left(\frac{1}{64}, \mathsf{*.f64}\left(i, \color{blue}{i}\right)\right)\right) \]
        7. Simplified99.4%

          \[\leadsto \color{blue}{0.0625 + \frac{0.015625}{i \cdot i}} \]
      7. Recombined 2 regimes into one program.
      8. Add Preprocessing

      Alternative 4: 98.9% accurate, 2.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;i \leq 0.5:\\ \;\;\;\;i \cdot \frac{i}{-4}\\ \mathbf{else}:\\ \;\;\;\;0.0625\\ \end{array} \end{array} \]
      (FPCore (i) :precision binary64 (if (<= i 0.5) (* i (/ i -4.0)) 0.0625))
      double code(double i) {
      	double tmp;
      	if (i <= 0.5) {
      		tmp = i * (i / -4.0);
      	} else {
      		tmp = 0.0625;
      	}
      	return tmp;
      }
      
      real(8) function code(i)
          real(8), intent (in) :: i
          real(8) :: tmp
          if (i <= 0.5d0) then
              tmp = i * (i / (-4.0d0))
          else
              tmp = 0.0625d0
          end if
          code = tmp
      end function
      
      public static double code(double i) {
      	double tmp;
      	if (i <= 0.5) {
      		tmp = i * (i / -4.0);
      	} else {
      		tmp = 0.0625;
      	}
      	return tmp;
      }
      
      def code(i):
      	tmp = 0
      	if i <= 0.5:
      		tmp = i * (i / -4.0)
      	else:
      		tmp = 0.0625
      	return tmp
      
      function code(i)
      	tmp = 0.0
      	if (i <= 0.5)
      		tmp = Float64(i * Float64(i / -4.0));
      	else
      		tmp = 0.0625;
      	end
      	return tmp
      end
      
      function tmp_2 = code(i)
      	tmp = 0.0;
      	if (i <= 0.5)
      		tmp = i * (i / -4.0);
      	else
      		tmp = 0.0625;
      	end
      	tmp_2 = tmp;
      end
      
      code[i_] := If[LessEqual[i, 0.5], N[(i * N[(i / -4.0), $MachinePrecision]), $MachinePrecision], 0.0625]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;i \leq 0.5:\\
      \;\;\;\;i \cdot \frac{i}{-4}\\
      
      \mathbf{else}:\\
      \;\;\;\;0.0625\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if i < 0.5

        1. Initial program 29.7%

          \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
        2. Step-by-step derivation
          1. associate-/l/N/A

            \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
          2. associate-*l*N/A

            \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
          3. associate-/l*N/A

            \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
          4. *-lowering-*.f64N/A

            \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
          5. swap-sqrN/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
          6. associate-*r*N/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
          7. times-fracN/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
          8. *-inversesN/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
          9. *-rgt-identityN/A

            \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
          10. /-lowering-/.f64N/A

            \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
          11. *-commutativeN/A

            \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
        3. Simplified100.0%

          \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
        4. Add Preprocessing
        5. Taylor expanded in i around 0

          \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{-4}\right)\right) \]
        6. Step-by-step derivation
          1. Simplified99.5%

            \[\leadsto i \cdot \frac{i}{\color{blue}{-4}} \]

          if 0.5 < i

          1. Initial program 21.6%

            \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
          2. Step-by-step derivation
            1. associate-/l/N/A

              \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
            2. associate-*l*N/A

              \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
            3. associate-/l*N/A

              \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
            4. *-lowering-*.f64N/A

              \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
            5. swap-sqrN/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
            6. associate-*r*N/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
            7. times-fracN/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
            8. *-inversesN/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
            9. *-rgt-identityN/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
            10. /-lowering-/.f64N/A

              \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
            11. *-commutativeN/A

              \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
          3. Simplified42.3%

            \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
          4. Add Preprocessing
          5. Taylor expanded in i around inf

            \[\leadsto \color{blue}{\frac{1}{16}} \]
          6. Step-by-step derivation
            1. Simplified99.2%

              \[\leadsto \color{blue}{0.0625} \]
          7. Recombined 2 regimes into one program.
          8. Add Preprocessing

          Alternative 5: 50.6% accurate, 25.0× speedup?

          \[\begin{array}{l} \\ 0.0625 \end{array} \]
          (FPCore (i) :precision binary64 0.0625)
          double code(double i) {
          	return 0.0625;
          }
          
          real(8) function code(i)
              real(8), intent (in) :: i
              code = 0.0625d0
          end function
          
          public static double code(double i) {
          	return 0.0625;
          }
          
          def code(i):
          	return 0.0625
          
          function code(i)
          	return 0.0625
          end
          
          function tmp = code(i)
          	tmp = 0.0625;
          end
          
          code[i_] := 0.0625
          
          \begin{array}{l}
          
          \\
          0.0625
          \end{array}
          
          Derivation
          1. Initial program 25.5%

            \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1} \]
          2. Step-by-step derivation
            1. associate-/l/N/A

              \[\leadsto \frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
            2. associate-*l*N/A

              \[\leadsto \frac{i \cdot \left(i \cdot \left(i \cdot i\right)\right)}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)} \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)} \]
            3. associate-/l*N/A

              \[\leadsto i \cdot \color{blue}{\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}} \]
            4. *-lowering-*.f64N/A

              \[\leadsto \mathsf{*.f64}\left(i, \color{blue}{\left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)\right)}\right)}\right) \]
            5. swap-sqrN/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(i \cdot i\right)}\right)}\right)\right) \]
            6. associate-*r*N/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i \cdot \left(i \cdot i\right)}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right) \cdot \color{blue}{\left(i \cdot i\right)}}\right)\right) \]
            7. times-fracN/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot \color{blue}{\frac{i \cdot i}{i \cdot i}}\right)\right) \]
            8. *-inversesN/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)} \cdot 1\right)\right) \]
            9. *-rgt-identityN/A

              \[\leadsto \mathsf{*.f64}\left(i, \left(\frac{i}{\color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}}\right)\right) \]
            10. /-lowering-/.f64N/A

              \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \color{blue}{\left(\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)\right)}\right)\right) \]
            11. *-commutativeN/A

              \[\leadsto \mathsf{*.f64}\left(i, \mathsf{/.f64}\left(i, \left(\left(2 \cdot 2\right) \cdot \color{blue}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right)}\right)\right)\right) \]
          3. Simplified70.0%

            \[\leadsto \color{blue}{i \cdot \frac{i}{\left(i \cdot i\right) \cdot 16 + -4}} \]
          4. Add Preprocessing
          5. Taylor expanded in i around inf

            \[\leadsto \color{blue}{\frac{1}{16}} \]
          6. Step-by-step derivation
            1. Simplified52.8%

              \[\leadsto \color{blue}{0.0625} \]
            2. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2024139 
            (FPCore (i)
              :name "Octave 3.8, jcobi/4, as called"
              :precision binary64
              :pre (> i 0.0)
              (/ (/ (* (* i i) (* i i)) (* (* 2.0 i) (* 2.0 i))) (- (* (* 2.0 i) (* 2.0 i)) 1.0)))