\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}\begin{array}{l}
\mathbf{if}\;i \le 217.9947108587691388947860104963183403015:\\
\;\;\;\;\frac{i \cdot i}{\left(\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1\right) \cdot \left(2 \cdot 2\right)}\\
\mathbf{else}:\\
\;\;\;\;0.00390625 \cdot \frac{1}{{i}^{4}} + \left(0.015625 \cdot \frac{1}{{i}^{2}} + 0.0625\right)\\
\end{array}double f(double i) {
double r51764 = i;
double r51765 = r51764 * r51764;
double r51766 = r51765 * r51765;
double r51767 = 2.0;
double r51768 = r51767 * r51764;
double r51769 = r51768 * r51768;
double r51770 = r51766 / r51769;
double r51771 = 1.0;
double r51772 = r51769 - r51771;
double r51773 = r51770 / r51772;
return r51773;
}
double f(double i) {
double r51774 = i;
double r51775 = 217.99471085876914;
bool r51776 = r51774 <= r51775;
double r51777 = r51774 * r51774;
double r51778 = 2.0;
double r51779 = r51778 * r51774;
double r51780 = r51779 * r51779;
double r51781 = 1.0;
double r51782 = r51780 - r51781;
double r51783 = r51778 * r51778;
double r51784 = r51782 * r51783;
double r51785 = r51777 / r51784;
double r51786 = 0.00390625;
double r51787 = 1.0;
double r51788 = 4.0;
double r51789 = pow(r51774, r51788);
double r51790 = r51787 / r51789;
double r51791 = r51786 * r51790;
double r51792 = 0.015625;
double r51793 = 2.0;
double r51794 = pow(r51774, r51793);
double r51795 = r51787 / r51794;
double r51796 = r51792 * r51795;
double r51797 = 0.0625;
double r51798 = r51796 + r51797;
double r51799 = r51791 + r51798;
double r51800 = r51776 ? r51785 : r51799;
return r51800;
}



Bits error versus i
Results
if i < 217.99471085876914Initial program 44.7
Simplified0.0
if 217.99471085876914 < i Initial program 48.4
Simplified32.6
Taylor expanded around inf 0.0
Final simplification0.0
herbie shell --seed 2020001
(FPCore (i)
:name "Octave 3.8, jcobi/4, as called"
:precision binary64
:pre (and (> i 0.0))
(/ (/ (* (* i i) (* i i)) (* (* 2 i) (* 2 i))) (- (* (* 2 i) (* 2 i)) 1)))