Cannot sample enough valid points. (more)

\[1 \le y \le 9999\]
\[\begin{array}{l} \mathbf{if}\;\left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) \cdot \left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) + {\left({10}^{-300}\right)}^{\left(10^{4} \cdot \left(y + 1\right)\right)} = 0.0:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\frac{e^{\left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) \cdot \left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) + {\left({10}^{-300}\right)}^{\left(10^{4} \cdot \left(y + 1\right)\right)}} - 1}{\left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) \cdot \left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) + {\left({10}^{-300}\right)}^{\left(10^{4} \cdot \left(y + 1\right)\right)}}\\ \end{array}\]
\begin{array}{l}
\mathbf{if}\;\left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) \cdot \left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) + {\left({10}^{-300}\right)}^{\left(10^{4} \cdot \left(y + 1\right)\right)} = 0.0:\\
\;\;\;\;1\\

\mathbf{else}:\\
\;\;\;\;\frac{e^{\left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) \cdot \left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) + {\left({10}^{-300}\right)}^{\left(10^{4} \cdot \left(y + 1\right)\right)}} - 1}{\left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) \cdot \left(\left|y - \sqrt{y \cdot y + 1}\right| - \frac{1}{y + \sqrt{y \cdot y + 1}}\right) + {\left({10}^{-300}\right)}^{\left(10^{4} \cdot \left(y + 1\right)\right)}}\\

\end{array}
double code(double y) {
	double VAR;
	if ((((double) (((double) (((double) (((double) fabs(((double) (y - ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))) - ((double) (1.0 / ((double) (y + ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))))) * ((double) (((double) fabs(((double) (y - ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))) - ((double) (1.0 / ((double) (y + ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))))))) + ((double) pow(((double) pow(10.0, -300.0)), ((double) (10000.0 * ((double) (y + 1.0)))))))) == 0.0)) {
		VAR = 1.0;
	} else {
		VAR = ((double) (((double) (((double) exp(((double) (((double) (((double) (((double) fabs(((double) (y - ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))) - ((double) (1.0 / ((double) (y + ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))))) * ((double) (((double) fabs(((double) (y - ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))) - ((double) (1.0 / ((double) (y + ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))))))) + ((double) pow(((double) pow(10.0, -300.0)), ((double) (10000.0 * ((double) (y + 1.0)))))))))) - 1.0)) / ((double) (((double) (((double) (((double) fabs(((double) (y - ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))) - ((double) (1.0 / ((double) (y + ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))))) * ((double) (((double) fabs(((double) (y - ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))) - ((double) (1.0 / ((double) (y + ((double) sqrt(((double) (((double) (y * y)) + 1.0)))))))))))) + ((double) pow(((double) pow(10.0, -300.0)), ((double) (10000.0 * ((double) (y + 1.0))))))))));
	}
	return VAR;
}

Reproduce

herbie shell --seed 2020150 
(FPCore (y)
  :name "Kahan's Unum-Targeted Monster"
  :precision binary64
  :pre (<= 1.0 y 9999.0)
  (if (== (+ (* (- (fabs (- y (sqrt (+ (* y y) 1.0)))) (/ 1.0 (+ y (sqrt (+ (* y y) 1.0))))) (- (fabs (- y (sqrt (+ (* y y) 1.0)))) (/ 1.0 (+ y (sqrt (+ (* y y) 1.0)))))) (pow (pow 10.0 -300.0) (* 10000.0 (+ y 1.0)))) 0.0) 1.0 (/ (- (exp (+ (* (- (fabs (- y (sqrt (+ (* y y) 1.0)))) (/ 1.0 (+ y (sqrt (+ (* y y) 1.0))))) (- (fabs (- y (sqrt (+ (* y y) 1.0)))) (/ 1.0 (+ y (sqrt (+ (* y y) 1.0)))))) (pow (pow 10.0 -300.0) (* 10000.0 (+ y 1.0))))) 1.0) (+ (* (- (fabs (- y (sqrt (+ (* y y) 1.0)))) (/ 1.0 (+ y (sqrt (+ (* y y) 1.0))))) (- (fabs (- y (sqrt (+ (* y y) 1.0)))) (/ 1.0 (+ y (sqrt (+ (* y y) 1.0)))))) (pow (pow 10.0 -300.0) (* 10000.0 (+ y 1.0)))))))