\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\begin{array}{l}
\mathbf{if}\;x \le -1.275446733100294322569082106078042215813 \cdot 10^{-5}:\\
\;\;\;\;\sqrt{\frac{e^{2 \cdot x} - 1}{\mathsf{fma}\left(-1, 1, e^{x + x}\right)} \cdot \mathsf{fma}\left(\sqrt{e^{x}}, \sqrt{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 r14133 = 2.0;
double r14134 = x;
double r14135 = r14133 * r14134;
double r14136 = exp(r14135);
double r14137 = 1.0;
double r14138 = r14136 - r14137;
double r14139 = exp(r14134);
double r14140 = r14139 - r14137;
double r14141 = r14138 / r14140;
double r14142 = sqrt(r14141);
return r14142;
}
double f(double x) {
double r14143 = x;
double r14144 = -1.2754467331002943e-05;
bool r14145 = r14143 <= r14144;
double r14146 = 2.0;
double r14147 = r14146 * r14143;
double r14148 = exp(r14147);
double r14149 = 1.0;
double r14150 = r14148 - r14149;
double r14151 = -r14149;
double r14152 = r14143 + r14143;
double r14153 = exp(r14152);
double r14154 = fma(r14151, r14149, r14153);
double r14155 = r14150 / r14154;
double r14156 = exp(r14143);
double r14157 = sqrt(r14156);
double r14158 = fma(r14157, r14157, r14149);
double r14159 = r14155 * r14158;
double r14160 = sqrt(r14159);
double r14161 = 0.5;
double r14162 = 2.0;
double r14163 = pow(r14143, r14162);
double r14164 = fma(r14149, r14143, r14146);
double r14165 = fma(r14161, r14163, r14164);
double r14166 = sqrt(r14165);
double r14167 = r14145 ? r14160 : r14166;
return r14167;
}



Bits error versus x
if x < -1.2754467331002943e-05Initial program 0.1
rmApplied flip--0.0
Applied associate-/r/0.0
Simplified0.0
rmApplied add-sqr-sqrt0.0
Applied fma-def0.0
if -1.2754467331002943e-05 < x Initial program 33.8
Taylor expanded around 0 6.8
Simplified6.8
Final simplification0.9
herbie shell --seed 2019354 +o rules:numerics
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
:precision binary64
(sqrt (/ (- (exp (* 2 x)) 1) (- (exp x) 1))))