\[1.11022 \cdot 10^{-16} \lt a \lt 9.0072 \cdot 10^{15} \land 1.11022 \cdot 10^{-16} \lt b \lt 9.0072 \cdot 10^{15} \land 1.11022 \cdot 10^{-16} \lt c \lt 9.0072 \cdot 10^{15}\]
\[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}\]
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
double f(double a, double b, double c) {
        double r6759 = b;
        double r6760 = -r6759;
        double r6761 = r6759 * r6759;
        double r6762 = 4.0;
        double r6763 = a;
        double r6764 = r6762 * r6763;
        double r6765 = c;
        double r6766 = r6764 * r6765;
        double r6767 = r6761 - r6766;
        double r6768 = sqrt(r6767);
        double r6769 = r6760 + r6768;
        double r6770 = 2.0;
        double r6771 = r6770 * r6763;
        double r6772 = r6769 / r6771;
        return r6772;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020045 
(FPCore (a b c)
  :name "Quadratic roots, medium range"
  :precision binary64
  :pre (and (< 1.11022e-16 a 9.0072e+15) (< 1.11022e-16 b 9.0072e+15) (< 1.11022e-16 c 9.0072e+15))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) (* 2 a)))

Backtrace

hash-ref: no value found for key key: '(pow #<enode 640(640)> #<enode 20(1907)>)LC
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt2706
update-leader!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt2650
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt772
prune-phase/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt740
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt804
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt762
(unnamed)/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt560
(unnamed)/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt380
simplify!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt2240
run-iter!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3270
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3654
run-improve47/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3460
.../more-scheme.rkt:261:28unknown
run/opt/racket-7.5/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.5/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.5/collects/racket/private/more-scheme.rkt26128