\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\begin{array}{l}
\mathbf{if}\;x \le -1.3921498547628525 \cdot 10^{-5}:\\
\;\;\;\;\sqrt{\frac{e^{2 \cdot x} - 1}{\mathsf{fma}\left(-1, 1, e^{x + x}\right)} \cdot \left(e^{x} + 1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(0.5, {x}^{2}, \mathsf{fma}\left(1, x, 2\right)\right)}\\
\end{array}double f(double x) {
double r8630 = 2.0;
double r8631 = x;
double r8632 = r8630 * r8631;
double r8633 = exp(r8632);
double r8634 = 1.0;
double r8635 = r8633 - r8634;
double r8636 = exp(r8631);
double r8637 = r8636 - r8634;
double r8638 = r8635 / r8637;
double r8639 = sqrt(r8638);
return r8639;
}
double f(double x) {
double r8640 = x;
double r8641 = -1.3921498547628525e-05;
bool r8642 = r8640 <= r8641;
double r8643 = 2.0;
double r8644 = r8643 * r8640;
double r8645 = exp(r8644);
double r8646 = 1.0;
double r8647 = r8645 - r8646;
double r8648 = -r8646;
double r8649 = r8640 + r8640;
double r8650 = exp(r8649);
double r8651 = fma(r8648, r8646, r8650);
double r8652 = r8647 / r8651;
double r8653 = exp(r8640);
double r8654 = r8653 + r8646;
double r8655 = r8652 * r8654;
double r8656 = sqrt(r8655);
double r8657 = 0.5;
double r8658 = 2.0;
double r8659 = pow(r8640, r8658);
double r8660 = fma(r8646, r8640, r8643);
double r8661 = fma(r8657, r8659, r8660);
double r8662 = sqrt(r8661);
double r8663 = r8642 ? r8656 : r8662;
return r8663;
}



Bits error versus x
if x < -1.3921498547628525e-05Initial program 0.1
rmApplied flip--0.0
Applied associate-/r/0.0
Simplified0.0
if -1.3921498547628525e-05 < x Initial program 34.0
Taylor expanded around 0 6.0
Simplified6.0
Final simplification0.8
herbie shell --seed 2020025 +o rules:numerics
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
:precision binary64
(sqrt (/ (- (exp (* 2 x)) 1) (- (exp x) 1))))