?

\[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
(FPCore (a b c)
 :precision binary64
 (/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))
double code(double a, double b, double c) {
	return (-b - sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (-b - sqrt(((b * b) - (4.0d0 * (a * c))))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b - Math.sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
}
def code(a, b, c):
	return (-b - math.sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(a * c))))) / Float64(2.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b - sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}

Reproduce?

Please include this information when filing a bug report:

herbie shell --seed 2023096 
(FPCore (a b c)
  :name "quadm (p42, negative)"
  :precision binary64

  :herbie-target
  (if (< b 0.0) (/ c (* a (/ (+ (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))) (/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))

  (/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))

Backtrace

match-define: no matching clause for '((x -.f64 (exp.f64 (log1p.f64 (sqrt.f64 (fma.f64 c (*.f64 a -4) (*.f64 b b))))) 1))LC
program-body/home/nightlies/herbie/remove-change/src/programs.rkt210
(unnamed)/usr/share/racket/collects/racket/contract/private/arrow-higher-order.rkt37933
gen-rewrites!/home/nightlies/herbie/remove-change/src/patch.rkt1450
patch-table-run/home/nightlies/herbie/remove-change/src/patch.rkt2960
(unnamed)/usr/share/racket/collects/racket/contract/private/arrow-val-first.rkt48618
run-iter!/home/nightlies/herbie/remove-change/src/mainloop.rkt2670
mutate!/home/nightlies/herbie/remove-change/src/mainloop.rkt3770
run-improve!/home/nightlies/herbie/remove-change/src/mainloop.rkt3250
run-herbie/home/nightlies/herbie/remove-change/src/sandbox.rkt570
(unnamed)/home/nightlies/herbie/remove-change/src/sandbox.rkt1336
(unnamed)/usr/share/racket/pkgs/profile-lib/main.rkt4010
profile-thunk/usr/share/racket/pkgs/profile-lib/main.rkt90
(unnamed)/usr/share/racket/collects/racket/engine.rkt4224