\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\begin{array}{l}
\mathbf{if}\;x \le -1.998472655500366441157916730375632141659 \cdot 10^{-5}:\\
\;\;\;\;\sqrt{\frac{\left(\sqrt{1} + \sqrt{e^{2 \cdot x}}\right) \cdot \left(\sqrt{e^{2 \cdot x}} - \sqrt{1}\right)}{e^{x} - 1}}\\
\mathbf{else}:\\
\;\;\;\;\frac{x \cdot 0.5}{\sqrt{2}} + \left(\sqrt{2} + \left(0.25 - \frac{0.125}{2}\right) \cdot \frac{x \cdot x}{\sqrt{2}}\right)\\
\end{array}double f(double x) {
double r1541562 = 2.0;
double r1541563 = x;
double r1541564 = r1541562 * r1541563;
double r1541565 = exp(r1541564);
double r1541566 = 1.0;
double r1541567 = r1541565 - r1541566;
double r1541568 = exp(r1541563);
double r1541569 = r1541568 - r1541566;
double r1541570 = r1541567 / r1541569;
double r1541571 = sqrt(r1541570);
return r1541571;
}
double f(double x) {
double r1541572 = x;
double r1541573 = -1.9984726555003664e-05;
bool r1541574 = r1541572 <= r1541573;
double r1541575 = 1.0;
double r1541576 = sqrt(r1541575);
double r1541577 = 2.0;
double r1541578 = r1541577 * r1541572;
double r1541579 = exp(r1541578);
double r1541580 = sqrt(r1541579);
double r1541581 = r1541576 + r1541580;
double r1541582 = r1541580 - r1541576;
double r1541583 = r1541581 * r1541582;
double r1541584 = exp(r1541572);
double r1541585 = r1541584 - r1541575;
double r1541586 = r1541583 / r1541585;
double r1541587 = sqrt(r1541586);
double r1541588 = 0.5;
double r1541589 = r1541572 * r1541588;
double r1541590 = sqrt(r1541577);
double r1541591 = r1541589 / r1541590;
double r1541592 = 0.25;
double r1541593 = 0.125;
double r1541594 = r1541593 / r1541577;
double r1541595 = r1541592 - r1541594;
double r1541596 = r1541572 * r1541572;
double r1541597 = r1541596 / r1541590;
double r1541598 = r1541595 * r1541597;
double r1541599 = r1541590 + r1541598;
double r1541600 = r1541591 + r1541599;
double r1541601 = r1541574 ? r1541587 : r1541600;
return r1541601;
}



Bits error versus x
Results
if x < -1.9984726555003664e-05Initial program 0.1
rmApplied add-sqr-sqrt0.1
Applied add-sqr-sqrt0.1
Applied difference-of-squares0.0
if -1.9984726555003664e-05 < x Initial program 34.0
Taylor expanded around 0 6.0
Simplified6.0
Taylor expanded around 0 6.0
Simplified6.0
Final simplification0.8
herbie shell --seed 2019200
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
(sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))