Cubic critical, wide range

Percentage Accurate: 18.1% → 97.6%
Time: 14.9s
Alternatives: 10
Speedup: 2.9×

Specification

?
\[\left(\left(4.930380657631324 \cdot 10^{-32} < a \land a < 2.028240960365167 \cdot 10^{+31}\right) \land \left(4.930380657631324 \cdot 10^{-32} < b \land b < 2.028240960365167 \cdot 10^{+31}\right)\right) \land \left(4.930380657631324 \cdot 10^{-32} < c \land c < 2.028240960365167 \cdot 10^{+31}\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * 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) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 10 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 18.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * 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) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\end{array}

Alternative 1: 97.6% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := b \cdot \left(b \cdot b\right)\\ \mathsf{fma}\left(\frac{c}{b}, -0.5, \mathsf{fma}\left(c, \mathsf{fma}\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(t\_0 \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot t\_0\right)}\right), \frac{a \cdot -0.375}{t\_0}\right) \cdot \left(c \cdot c\right)\right) \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (* b (* b b))))
   (fma
    (/ c b)
    -0.5
    (*
     (fma
      c
      (fma
       (* a (* a (* a a)))
       (/ (* c -1.0546875) (* (* b b) (* t_0 (* a (* b b)))))
       (/ (* (* a a) -0.5625) (* b (* b t_0))))
      (/ (* a -0.375) t_0))
     (* c c)))))
double code(double a, double b, double c) {
	double t_0 = b * (b * b);
	return fma((c / b), -0.5, (fma(c, fma((a * (a * (a * a))), ((c * -1.0546875) / ((b * b) * (t_0 * (a * (b * b))))), (((a * a) * -0.5625) / (b * (b * t_0)))), ((a * -0.375) / t_0)) * (c * c)));
}
function code(a, b, c)
	t_0 = Float64(b * Float64(b * b))
	return fma(Float64(c / b), -0.5, Float64(fma(c, fma(Float64(a * Float64(a * Float64(a * a))), Float64(Float64(c * -1.0546875) / Float64(Float64(b * b) * Float64(t_0 * Float64(a * Float64(b * b))))), Float64(Float64(Float64(a * a) * -0.5625) / Float64(b * Float64(b * t_0)))), Float64(Float64(a * -0.375) / t_0)) * Float64(c * c)))
end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(c / b), $MachinePrecision] * -0.5 + N[(N[(c * N[(N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(c * -1.0546875), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * N[(t$95$0 * N[(a * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] / N[(b * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a * -0.375), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot b\right)\\
\mathsf{fma}\left(\frac{c}{b}, -0.5, \mathsf{fma}\left(c, \mathsf{fma}\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(t\_0 \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot t\_0\right)}\right), \frac{a \cdot -0.375}{t\_0}\right) \cdot \left(c \cdot c\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 19.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in c around 0

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}} + c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2}}{{b}^{5}} + \frac{-1}{6} \cdot \frac{c \cdot \left(\frac{81}{64} \cdot \frac{{a}^{4}}{{b}^{6}} + \frac{81}{16} \cdot \frac{{a}^{4}}{{b}^{6}}\right)}{a \cdot b}\right)\right) - \frac{1}{2} \cdot \frac{1}{b}\right)} \]
  4. Applied rewrites97.4%

    \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(-0.16666666666666666, \frac{\frac{{a}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot c\right)}{a \cdot b}, \frac{\left(a \cdot a\right) \cdot -0.5625}{{b}^{5}}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right)} \]
  5. Applied rewrites97.7%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(c, \mathsf{fma}\left(a, a \cdot \frac{-0.5625}{\left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right) \cdot b}, \frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(6.328125 \cdot c\right)}{\left(b \cdot \left(\left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right) \cdot b\right)\right) \cdot \left(a \cdot b\right)} \cdot -0.16666666666666666\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \color{blue}{c \cdot c}, \frac{c}{b \cdot -2}\right) \]
  6. Applied rewrites97.4%

    \[\leadsto \mathsf{fma}\left(\frac{-0.5}{b}, \color{blue}{c}, \mathsf{fma}\left(c, \mathsf{fma}\left(a, \frac{a \cdot -0.5625}{b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(6.328125 \cdot c\right) \cdot -0.16666666666666666\right)}{\left(b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)\right) \cdot \left(b \cdot \left(a \cdot b\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right) \cdot \left(c \cdot c\right)\right) \]
  7. Applied rewrites97.7%

    \[\leadsto \mathsf{fma}\left(\frac{c}{b}, \color{blue}{-0.5}, \mathsf{fma}\left(c, \mathsf{fma}\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right) \cdot \left(c \cdot c\right)\right) \]
  8. Add Preprocessing

Alternative 2: 97.3% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := b \cdot \left(b \cdot b\right)\\ \mathsf{fma}\left(\frac{-0.5}{b}, c, \left(c \cdot c\right) \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(t\_0 \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot t\_0\right)}\right), \frac{a \cdot -0.375}{t\_0}\right)\right) \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (* b (* b b))))
   (fma
    (/ -0.5 b)
    c
    (*
     (* c c)
     (fma
      c
      (fma
       (/ (* c -1.0546875) (* (* b b) (* t_0 (* a (* b b)))))
       (* a (* a (* a a)))
       (/ (* (* a a) -0.5625) (* b (* b t_0))))
      (/ (* a -0.375) t_0))))))
double code(double a, double b, double c) {
	double t_0 = b * (b * b);
	return fma((-0.5 / b), c, ((c * c) * fma(c, fma(((c * -1.0546875) / ((b * b) * (t_0 * (a * (b * b))))), (a * (a * (a * a))), (((a * a) * -0.5625) / (b * (b * t_0)))), ((a * -0.375) / t_0))));
}
function code(a, b, c)
	t_0 = Float64(b * Float64(b * b))
	return fma(Float64(-0.5 / b), c, Float64(Float64(c * c) * fma(c, fma(Float64(Float64(c * -1.0546875) / Float64(Float64(b * b) * Float64(t_0 * Float64(a * Float64(b * b))))), Float64(a * Float64(a * Float64(a * a))), Float64(Float64(Float64(a * a) * -0.5625) / Float64(b * Float64(b * t_0)))), Float64(Float64(a * -0.375) / t_0))))
end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(-0.5 / b), $MachinePrecision] * c + N[(N[(c * c), $MachinePrecision] * N[(c * N[(N[(N[(c * -1.0546875), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * N[(t$95$0 * N[(a * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] / N[(b * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a * -0.375), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot b\right)\\
\mathsf{fma}\left(\frac{-0.5}{b}, c, \left(c \cdot c\right) \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(t\_0 \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot t\_0\right)}\right), \frac{a \cdot -0.375}{t\_0}\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 19.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in c around 0

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}} + c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2}}{{b}^{5}} + \frac{-1}{6} \cdot \frac{c \cdot \left(\frac{81}{64} \cdot \frac{{a}^{4}}{{b}^{6}} + \frac{81}{16} \cdot \frac{{a}^{4}}{{b}^{6}}\right)}{a \cdot b}\right)\right) - \frac{1}{2} \cdot \frac{1}{b}\right)} \]
  4. Applied rewrites97.4%

    \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(-0.16666666666666666, \frac{\frac{{a}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot c\right)}{a \cdot b}, \frac{\left(a \cdot a\right) \cdot -0.5625}{{b}^{5}}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right)} \]
  5. Applied rewrites97.7%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(c, \mathsf{fma}\left(a, a \cdot \frac{-0.5625}{\left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right) \cdot b}, \frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(6.328125 \cdot c\right)}{\left(b \cdot \left(\left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right) \cdot b\right)\right) \cdot \left(a \cdot b\right)} \cdot -0.16666666666666666\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \color{blue}{c \cdot c}, \frac{c}{b \cdot -2}\right) \]
  6. Applied rewrites97.4%

    \[\leadsto \mathsf{fma}\left(\frac{-0.5}{b}, \color{blue}{c}, \mathsf{fma}\left(c, \mathsf{fma}\left(a, \frac{a \cdot -0.5625}{b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(6.328125 \cdot c\right) \cdot -0.16666666666666666\right)}{\left(b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)\right) \cdot \left(b \cdot \left(a \cdot b\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right) \cdot \left(c \cdot c\right)\right) \]
  7. Step-by-step derivation
    1. Applied rewrites97.4%

      \[\leadsto \mathsf{fma}\left(\frac{-0.5}{b}, c, \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right) \cdot \left(c \cdot c\right)\right) \]
    2. Final simplification97.4%

      \[\leadsto \mathsf{fma}\left(\frac{-0.5}{b}, c, \left(c \cdot c\right) \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right)\right) \]
    3. Add Preprocessing

    Alternative 3: 97.3% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := b \cdot \left(b \cdot b\right)\\ c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(t\_0 \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot t\_0\right)}\right), \frac{a \cdot -0.375}{t\_0}\right), \frac{-0.5}{b}\right) \end{array} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (let* ((t_0 (* b (* b b))))
       (*
        c
        (fma
         c
         (fma
          c
          (fma
           (* a (* a (* a a)))
           (/ (* c -1.0546875) (* (* b b) (* t_0 (* a (* b b)))))
           (/ (* (* a a) -0.5625) (* b (* b t_0))))
          (/ (* a -0.375) t_0))
         (/ -0.5 b)))))
    double code(double a, double b, double c) {
    	double t_0 = b * (b * b);
    	return c * fma(c, fma(c, fma((a * (a * (a * a))), ((c * -1.0546875) / ((b * b) * (t_0 * (a * (b * b))))), (((a * a) * -0.5625) / (b * (b * t_0)))), ((a * -0.375) / t_0)), (-0.5 / b));
    }
    
    function code(a, b, c)
    	t_0 = Float64(b * Float64(b * b))
    	return Float64(c * fma(c, fma(c, fma(Float64(a * Float64(a * Float64(a * a))), Float64(Float64(c * -1.0546875) / Float64(Float64(b * b) * Float64(t_0 * Float64(a * Float64(b * b))))), Float64(Float64(Float64(a * a) * -0.5625) / Float64(b * Float64(b * t_0)))), Float64(Float64(a * -0.375) / t_0)), Float64(-0.5 / b)))
    end
    
    code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(c * N[(c * N[(c * N[(N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(c * -1.0546875), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * N[(t$95$0 * N[(a * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] / N[(b * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a * -0.375), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] + N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := b \cdot \left(b \cdot b\right)\\
    c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(t\_0 \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot t\_0\right)}\right), \frac{a \cdot -0.375}{t\_0}\right), \frac{-0.5}{b}\right)
    \end{array}
    \end{array}
    
    Derivation
    1. Initial program 19.0%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Taylor expanded in c around 0

      \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}} + c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2}}{{b}^{5}} + \frac{-1}{6} \cdot \frac{c \cdot \left(\frac{81}{64} \cdot \frac{{a}^{4}}{{b}^{6}} + \frac{81}{16} \cdot \frac{{a}^{4}}{{b}^{6}}\right)}{a \cdot b}\right)\right) - \frac{1}{2} \cdot \frac{1}{b}\right)} \]
    4. Applied rewrites97.4%

      \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(-0.16666666666666666, \frac{\frac{{a}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot c\right)}{a \cdot b}, \frac{\left(a \cdot a\right) \cdot -0.5625}{{b}^{5}}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right)} \]
    5. Applied rewrites97.7%

      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(c, \mathsf{fma}\left(a, a \cdot \frac{-0.5625}{\left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right) \cdot b}, \frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(6.328125 \cdot c\right)}{\left(b \cdot \left(\left(\left(b \cdot b\right) \cdot \left(b \cdot b\right)\right) \cdot b\right)\right) \cdot \left(a \cdot b\right)} \cdot -0.16666666666666666\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \color{blue}{c \cdot c}, \frac{c}{b \cdot -2}\right) \]
    6. Applied rewrites97.4%

      \[\leadsto \mathsf{fma}\left(\frac{-0.5}{b}, \color{blue}{c}, \mathsf{fma}\left(c, \mathsf{fma}\left(a, \frac{a \cdot -0.5625}{b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(6.328125 \cdot c\right) \cdot -0.16666666666666666\right)}{\left(b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)\right) \cdot \left(b \cdot \left(a \cdot b\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right) \cdot \left(c \cdot c\right)\right) \]
    7. Applied rewrites97.4%

      \[\leadsto c \cdot \color{blue}{\mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right), \frac{c \cdot -1.0546875}{\left(b \cdot b\right) \cdot \left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(a \cdot \left(b \cdot b\right)\right)\right)}, \frac{\left(a \cdot a\right) \cdot -0.5625}{b \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right)} \]
    8. Add Preprocessing

    Alternative 4: 95.9% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{a \cdot a}{b}\\ \frac{\frac{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(-4.5, t\_0, \mathsf{fma}\left(-1.6875, \frac{c \cdot \left(a \cdot \left(a \cdot a\right)\right)}{b \cdot \left(b \cdot b\right)}, t\_0 \cdot 1.125\right)\right), -1.5 \cdot \left(b \cdot a\right)\right)}{b \cdot \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)}}}{3 \cdot a} \end{array} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (let* ((t_0 (/ (* a a) b)))
       (/
        (/
         (*
          c
          (fma
           c
           (fma
            -4.5
            t_0
            (fma -1.6875 (/ (* c (* a (* a a))) (* b (* b b))) (* t_0 1.125)))
           (* -1.5 (* b a))))
         (* b (sqrt (fma 3.0 (* a c) (* b b)))))
        (* 3.0 a))))
    double code(double a, double b, double c) {
    	double t_0 = (a * a) / b;
    	return ((c * fma(c, fma(-4.5, t_0, fma(-1.6875, ((c * (a * (a * a))) / (b * (b * b))), (t_0 * 1.125))), (-1.5 * (b * a)))) / (b * sqrt(fma(3.0, (a * c), (b * b))))) / (3.0 * a);
    }
    
    function code(a, b, c)
    	t_0 = Float64(Float64(a * a) / b)
    	return Float64(Float64(Float64(c * fma(c, fma(-4.5, t_0, fma(-1.6875, Float64(Float64(c * Float64(a * Float64(a * a))) / Float64(b * Float64(b * b))), Float64(t_0 * 1.125))), Float64(-1.5 * Float64(b * a)))) / Float64(b * sqrt(fma(3.0, Float64(a * c), Float64(b * b))))) / Float64(3.0 * a))
    end
    
    code[a_, b_, c_] := Block[{t$95$0 = N[(N[(a * a), $MachinePrecision] / b), $MachinePrecision]}, N[(N[(N[(c * N[(c * N[(-4.5 * t$95$0 + N[(-1.6875 * N[(N[(c * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(t$95$0 * 1.125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.5 * N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[Sqrt[N[(3.0 * N[(a * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \frac{a \cdot a}{b}\\
    \frac{\frac{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(-4.5, t\_0, \mathsf{fma}\left(-1.6875, \frac{c \cdot \left(a \cdot \left(a \cdot a\right)\right)}{b \cdot \left(b \cdot b\right)}, t\_0 \cdot 1.125\right)\right), -1.5 \cdot \left(b \cdot a\right)\right)}{b \cdot \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)}}}{3 \cdot a}
    \end{array}
    \end{array}
    
    Derivation
    1. Initial program 19.0%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Applied rewrites18.6%

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{\mathsf{fma}\left(-9, a \cdot \left(c \cdot \left(a \cdot c\right)\right), b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)} \cdot b - \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot \left(b \cdot b\right)}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}}{3 \cdot a} \]
    4. Taylor expanded in c around 0

      \[\leadsto \frac{\frac{\color{blue}{c \cdot \left(c \cdot \left(\left(\frac{-9}{2} \cdot \frac{{a}^{2}}{b} + \frac{-27}{16} \cdot \frac{{a}^{3} \cdot c}{{b}^{3}}\right) - \frac{-9}{8} \cdot \frac{{a}^{2}}{b}\right) - \frac{3}{2} \cdot \left(a \cdot b\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
    5. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{c \cdot \left(c \cdot \left(\left(\frac{-9}{2} \cdot \frac{{a}^{2}}{b} + \frac{-27}{16} \cdot \frac{{a}^{3} \cdot c}{{b}^{3}}\right) - \frac{-9}{8} \cdot \frac{{a}^{2}}{b}\right) - \frac{3}{2} \cdot \left(a \cdot b\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
      2. sub-negN/A

        \[\leadsto \frac{\frac{c \cdot \color{blue}{\left(c \cdot \left(\left(\frac{-9}{2} \cdot \frac{{a}^{2}}{b} + \frac{-27}{16} \cdot \frac{{a}^{3} \cdot c}{{b}^{3}}\right) - \frac{-9}{8} \cdot \frac{{a}^{2}}{b}\right) + \left(\mathsf{neg}\left(\frac{3}{2} \cdot \left(a \cdot b\right)\right)\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
      3. lower-fma.f64N/A

        \[\leadsto \frac{\frac{c \cdot \color{blue}{\mathsf{fma}\left(c, \left(\frac{-9}{2} \cdot \frac{{a}^{2}}{b} + \frac{-27}{16} \cdot \frac{{a}^{3} \cdot c}{{b}^{3}}\right) - \frac{-9}{8} \cdot \frac{{a}^{2}}{b}, \mathsf{neg}\left(\frac{3}{2} \cdot \left(a \cdot b\right)\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
    6. Applied rewrites96.1%

      \[\leadsto \frac{\frac{\color{blue}{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(-4.5, \frac{a \cdot a}{b}, \mathsf{fma}\left(-1.6875, \frac{\left(a \cdot \left(a \cdot a\right)\right) \cdot c}{b \cdot \left(b \cdot b\right)}, 1.125 \cdot \frac{a \cdot a}{b}\right)\right), -1.5 \cdot \left(a \cdot b\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
    7. Final simplification96.1%

      \[\leadsto \frac{\frac{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(-4.5, \frac{a \cdot a}{b}, \mathsf{fma}\left(-1.6875, \frac{c \cdot \left(a \cdot \left(a \cdot a\right)\right)}{b \cdot \left(b \cdot b\right)}, \frac{a \cdot a}{b} \cdot 1.125\right)\right), -1.5 \cdot \left(b \cdot a\right)\right)}{b \cdot \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)}}}{3 \cdot a} \]
    8. Add Preprocessing

    Alternative 5: 95.9% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{c \cdot c}{b}\\ \frac{\frac{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(-4.5, t\_0, \mathsf{fma}\left(-1.6875, \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}, 1.125 \cdot t\_0\right)\right), -1.5 \cdot \left(b \cdot c\right)\right)}{b \cdot \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)}}}{3 \cdot a} \end{array} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (let* ((t_0 (/ (* c c) b)))
       (/
        (/
         (*
          a
          (fma
           a
           (fma
            -4.5
            t_0
            (fma -1.6875 (/ (* a (* c (* c c))) (* b (* b b))) (* 1.125 t_0)))
           (* -1.5 (* b c))))
         (* b (sqrt (fma 3.0 (* a c) (* b b)))))
        (* 3.0 a))))
    double code(double a, double b, double c) {
    	double t_0 = (c * c) / b;
    	return ((a * fma(a, fma(-4.5, t_0, fma(-1.6875, ((a * (c * (c * c))) / (b * (b * b))), (1.125 * t_0))), (-1.5 * (b * c)))) / (b * sqrt(fma(3.0, (a * c), (b * b))))) / (3.0 * a);
    }
    
    function code(a, b, c)
    	t_0 = Float64(Float64(c * c) / b)
    	return Float64(Float64(Float64(a * fma(a, fma(-4.5, t_0, fma(-1.6875, Float64(Float64(a * Float64(c * Float64(c * c))) / Float64(b * Float64(b * b))), Float64(1.125 * t_0))), Float64(-1.5 * Float64(b * c)))) / Float64(b * sqrt(fma(3.0, Float64(a * c), Float64(b * b))))) / Float64(3.0 * a))
    end
    
    code[a_, b_, c_] := Block[{t$95$0 = N[(N[(c * c), $MachinePrecision] / b), $MachinePrecision]}, N[(N[(N[(a * N[(a * N[(-4.5 * t$95$0 + N[(-1.6875 * N[(N[(a * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.125 * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.5 * N[(b * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[Sqrt[N[(3.0 * N[(a * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \frac{c \cdot c}{b}\\
    \frac{\frac{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(-4.5, t\_0, \mathsf{fma}\left(-1.6875, \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}, 1.125 \cdot t\_0\right)\right), -1.5 \cdot \left(b \cdot c\right)\right)}{b \cdot \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)}}}{3 \cdot a}
    \end{array}
    \end{array}
    
    Derivation
    1. Initial program 19.0%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Applied rewrites18.6%

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{\mathsf{fma}\left(-9, a \cdot \left(c \cdot \left(a \cdot c\right)\right), b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)} \cdot b - \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot \left(b \cdot b\right)}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}}{3 \cdot a} \]
    4. Taylor expanded in a around 0

      \[\leadsto \frac{\frac{\color{blue}{a \cdot \left(a \cdot \left(\left(\frac{-9}{2} \cdot \frac{{c}^{2}}{b} + \frac{-27}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{3}}\right) - \frac{-9}{8} \cdot \frac{{c}^{2}}{b}\right) - \frac{3}{2} \cdot \left(b \cdot c\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
    5. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \frac{\frac{\color{blue}{a \cdot \left(a \cdot \left(\left(\frac{-9}{2} \cdot \frac{{c}^{2}}{b} + \frac{-27}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{3}}\right) - \frac{-9}{8} \cdot \frac{{c}^{2}}{b}\right) - \frac{3}{2} \cdot \left(b \cdot c\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
      2. sub-negN/A

        \[\leadsto \frac{\frac{a \cdot \color{blue}{\left(a \cdot \left(\left(\frac{-9}{2} \cdot \frac{{c}^{2}}{b} + \frac{-27}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{3}}\right) - \frac{-9}{8} \cdot \frac{{c}^{2}}{b}\right) + \left(\mathsf{neg}\left(\frac{3}{2} \cdot \left(b \cdot c\right)\right)\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
      3. lower-fma.f64N/A

        \[\leadsto \frac{\frac{a \cdot \color{blue}{\mathsf{fma}\left(a, \left(\frac{-9}{2} \cdot \frac{{c}^{2}}{b} + \frac{-27}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{3}}\right) - \frac{-9}{8} \cdot \frac{{c}^{2}}{b}, \mathsf{neg}\left(\frac{3}{2} \cdot \left(b \cdot c\right)\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
    6. Applied rewrites96.1%

      \[\leadsto \frac{\frac{\color{blue}{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(-4.5, \frac{c \cdot c}{b}, \mathsf{fma}\left(-1.6875, \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}, 1.125 \cdot \frac{c \cdot c}{b}\right)\right), -1.5 \cdot \left(b \cdot c\right)\right)}}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}{3 \cdot a} \]
    7. Final simplification96.1%

      \[\leadsto \frac{\frac{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(-4.5, \frac{c \cdot c}{b}, \mathsf{fma}\left(-1.6875, \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}, 1.125 \cdot \frac{c \cdot c}{b}\right)\right), -1.5 \cdot \left(b \cdot c\right)\right)}{b \cdot \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)}}}{3 \cdot a} \]
    8. Add Preprocessing

    Alternative 6: 95.9% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \frac{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(b, \frac{c \cdot c}{b \cdot b} \cdot -3.375, -1.6875 \cdot \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}\right), -1.5 \cdot \left(b \cdot c\right)\right)}{\left(3 \cdot a\right) \cdot \left(b \cdot \sqrt{\mathsf{fma}\left(a, 3 \cdot c, b \cdot b\right)}\right)} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (/
      (*
       a
       (fma
        a
        (fma
         b
         (* (/ (* c c) (* b b)) -3.375)
         (* -1.6875 (/ (* a (* c (* c c))) (* b (* b b)))))
        (* -1.5 (* b c))))
      (* (* 3.0 a) (* b (sqrt (fma a (* 3.0 c) (* b b)))))))
    double code(double a, double b, double c) {
    	return (a * fma(a, fma(b, (((c * c) / (b * b)) * -3.375), (-1.6875 * ((a * (c * (c * c))) / (b * (b * b))))), (-1.5 * (b * c)))) / ((3.0 * a) * (b * sqrt(fma(a, (3.0 * c), (b * b)))));
    }
    
    function code(a, b, c)
    	return Float64(Float64(a * fma(a, fma(b, Float64(Float64(Float64(c * c) / Float64(b * b)) * -3.375), Float64(-1.6875 * Float64(Float64(a * Float64(c * Float64(c * c))) / Float64(b * Float64(b * b))))), Float64(-1.5 * Float64(b * c)))) / Float64(Float64(3.0 * a) * Float64(b * sqrt(fma(a, Float64(3.0 * c), Float64(b * b))))))
    end
    
    code[a_, b_, c_] := N[(N[(a * N[(a * N[(b * N[(N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] * -3.375), $MachinePrecision] + N[(-1.6875 * N[(N[(a * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.5 * N[(b * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(3.0 * a), $MachinePrecision] * N[(b * N[Sqrt[N[(a * N[(3.0 * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(b, \frac{c \cdot c}{b \cdot b} \cdot -3.375, -1.6875 \cdot \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}\right), -1.5 \cdot \left(b \cdot c\right)\right)}{\left(3 \cdot a\right) \cdot \left(b \cdot \sqrt{\mathsf{fma}\left(a, 3 \cdot c, b \cdot b\right)}\right)}
    \end{array}
    
    Derivation
    1. Initial program 19.0%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Applied rewrites18.6%

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{\mathsf{fma}\left(-9, a \cdot \left(c \cdot \left(a \cdot c\right)\right), b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)} \cdot b - \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot \left(b \cdot b\right)}{\sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)} \cdot b}}}{3 \cdot a} \]
    4. Applied rewrites19.0%

      \[\leadsto \color{blue}{\frac{-b \cdot \left(\sqrt{\mathsf{fma}\left(a, \left(a \cdot \left(c \cdot c\right)\right) \cdot -9, \left(b \cdot b\right) \cdot \left(b \cdot b\right)\right)} - b \cdot \sqrt{\mathsf{fma}\left(a, c \cdot 3, b \cdot b\right)}\right)}{\left(a \cdot 3\right) \cdot \left(\left(-b\right) \cdot \sqrt{\mathsf{fma}\left(a, c \cdot 3, b \cdot b\right)}\right)}} \]
    5. Taylor expanded in a around 0

      \[\leadsto \frac{\mathsf{neg}\left(\color{blue}{a \cdot \left(\frac{-3}{2} \cdot \left(b \cdot c\right) + a \cdot \left(\frac{-27}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{3}} + b \cdot \left(\frac{-9}{2} \cdot \frac{{c}^{2}}{{b}^{2}} - \frac{-9}{8} \cdot \frac{{c}^{2}}{{b}^{2}}\right)\right)\right)}\right)}{\left(a \cdot 3\right) \cdot \left(\left(\mathsf{neg}\left(b\right)\right) \cdot \sqrt{\mathsf{fma}\left(a, c \cdot 3, b \cdot b\right)}\right)} \]
    6. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{neg}\left(\color{blue}{a \cdot \left(\frac{-3}{2} \cdot \left(b \cdot c\right) + a \cdot \left(\frac{-27}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{3}} + b \cdot \left(\frac{-9}{2} \cdot \frac{{c}^{2}}{{b}^{2}} - \frac{-9}{8} \cdot \frac{{c}^{2}}{{b}^{2}}\right)\right)\right)}\right)}{\left(a \cdot 3\right) \cdot \left(\left(\mathsf{neg}\left(b\right)\right) \cdot \sqrt{\mathsf{fma}\left(a, c \cdot 3, b \cdot b\right)}\right)} \]
      2. +-commutativeN/A

        \[\leadsto \frac{\mathsf{neg}\left(a \cdot \color{blue}{\left(a \cdot \left(\frac{-27}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{3}} + b \cdot \left(\frac{-9}{2} \cdot \frac{{c}^{2}}{{b}^{2}} - \frac{-9}{8} \cdot \frac{{c}^{2}}{{b}^{2}}\right)\right) + \frac{-3}{2} \cdot \left(b \cdot c\right)\right)}\right)}{\left(a \cdot 3\right) \cdot \left(\left(\mathsf{neg}\left(b\right)\right) \cdot \sqrt{\mathsf{fma}\left(a, c \cdot 3, b \cdot b\right)}\right)} \]
      3. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{neg}\left(a \cdot \color{blue}{\mathsf{fma}\left(a, \frac{-27}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{3}} + b \cdot \left(\frac{-9}{2} \cdot \frac{{c}^{2}}{{b}^{2}} - \frac{-9}{8} \cdot \frac{{c}^{2}}{{b}^{2}}\right), \frac{-3}{2} \cdot \left(b \cdot c\right)\right)}\right)}{\left(a \cdot 3\right) \cdot \left(\left(\mathsf{neg}\left(b\right)\right) \cdot \sqrt{\mathsf{fma}\left(a, c \cdot 3, b \cdot b\right)}\right)} \]
    7. Applied rewrites96.1%

      \[\leadsto \frac{-\color{blue}{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(b, \frac{c \cdot c}{b \cdot b} \cdot -3.375, -1.6875 \cdot \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}\right), -1.5 \cdot \left(b \cdot c\right)\right)}}{\left(a \cdot 3\right) \cdot \left(\left(-b\right) \cdot \sqrt{\mathsf{fma}\left(a, c \cdot 3, b \cdot b\right)}\right)} \]
    8. Final simplification96.1%

      \[\leadsto \frac{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(b, \frac{c \cdot c}{b \cdot b} \cdot -3.375, -1.6875 \cdot \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}\right), -1.5 \cdot \left(b \cdot c\right)\right)}{\left(3 \cdot a\right) \cdot \left(b \cdot \sqrt{\mathsf{fma}\left(a, 3 \cdot c, b \cdot b\right)}\right)} \]
    9. Add Preprocessing

    Alternative 7: 95.2% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(a, \frac{-0.375 \cdot \left(c \cdot c\right)}{b \cdot b}, c \cdot -0.5\right)}{b} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (/ (fma a (/ (* -0.375 (* c c)) (* b b)) (* c -0.5)) b))
    double code(double a, double b, double c) {
    	return fma(a, ((-0.375 * (c * c)) / (b * b)), (c * -0.5)) / b;
    }
    
    function code(a, b, c)
    	return Float64(fma(a, Float64(Float64(-0.375 * Float64(c * c)) / Float64(b * b)), Float64(c * -0.5)) / b)
    end
    
    code[a_, b_, c_] := N[(N[(a * N[(N[(-0.375 * N[(c * c), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(c * -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{\mathsf{fma}\left(a, \frac{-0.375 \cdot \left(c \cdot c\right)}{b \cdot b}, c \cdot -0.5\right)}{b}
    \end{array}
    
    Derivation
    1. Initial program 19.0%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Taylor expanded in b around inf

      \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot c + \frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot c + \frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
    5. Applied rewrites95.4%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a, \frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot b}, c \cdot -0.5\right)}{b}} \]
    6. Final simplification95.4%

      \[\leadsto \frac{\mathsf{fma}\left(a, \frac{-0.375 \cdot \left(c \cdot c\right)}{b \cdot b}, c \cdot -0.5\right)}{b} \]
    7. Add Preprocessing

    Alternative 8: 95.2% accurate, 1.1× speedup?

    \[\begin{array}{l} \\ \frac{c \cdot \mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{b} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (/ (* c (fma -0.375 (/ (* a c) (* b b)) -0.5)) b))
    double code(double a, double b, double c) {
    	return (c * fma(-0.375, ((a * c) / (b * b)), -0.5)) / b;
    }
    
    function code(a, b, c)
    	return Float64(Float64(c * fma(-0.375, Float64(Float64(a * c) / Float64(b * b)), -0.5)) / b)
    end
    
    code[a_, b_, c_] := N[(N[(c * N[(-0.375 * N[(N[(a * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{c \cdot \mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{b}
    \end{array}
    
    Derivation
    1. Initial program 19.0%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Applied rewrites19.2%

      \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(a, -3 \cdot c, b \cdot b\right)}{b + \sqrt{\mathsf{fma}\left(a, -3 \cdot c, b \cdot b\right)}} - \frac{b \cdot b}{b + \sqrt{\mathsf{fma}\left(a, -3 \cdot c, b \cdot b\right)}}}}{3 \cdot a} \]
    4. Taylor expanded in b around inf

      \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot c + \frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
    5. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot c + \frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
      2. lower-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{2}, c, \frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}\right)}}{b} \]
      3. associate-*r/N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{2}, c, \color{blue}{\frac{\frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)}{{b}^{2}}}\right)}{b} \]
      4. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{2}, c, \color{blue}{\frac{\frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)}{{b}^{2}}}\right)}{b} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{2}, c, \frac{\color{blue}{\frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)}}{{b}^{2}}\right)}{b} \]
      6. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{2}, c, \frac{\frac{-3}{8} \cdot \color{blue}{\left(a \cdot {c}^{2}\right)}}{{b}^{2}}\right)}{b} \]
      7. unpow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{2}, c, \frac{\frac{-3}{8} \cdot \left(a \cdot \color{blue}{\left(c \cdot c\right)}\right)}{{b}^{2}}\right)}{b} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{2}, c, \frac{\frac{-3}{8} \cdot \left(a \cdot \color{blue}{\left(c \cdot c\right)}\right)}{{b}^{2}}\right)}{b} \]
      9. unpow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{-1}{2}, c, \frac{\frac{-3}{8} \cdot \left(a \cdot \left(c \cdot c\right)\right)}{\color{blue}{b \cdot b}}\right)}{b} \]
      10. lower-*.f6495.4

        \[\leadsto \frac{\mathsf{fma}\left(-0.5, c, \frac{-0.375 \cdot \left(a \cdot \left(c \cdot c\right)\right)}{\color{blue}{b \cdot b}}\right)}{b} \]
    6. Applied rewrites95.4%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-0.5, c, \frac{-0.375 \cdot \left(a \cdot \left(c \cdot c\right)\right)}{b \cdot b}\right)}{b}} \]
    7. Taylor expanded in c around 0

      \[\leadsto \frac{c \cdot \left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{2}} - \frac{1}{2}\right)}{b} \]
    8. Step-by-step derivation
      1. Applied rewrites95.4%

        \[\leadsto \frac{c \cdot \mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{b} \]
      2. Add Preprocessing

      Alternative 9: 94.9% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ c \cdot \frac{\mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{b} \end{array} \]
      (FPCore (a b c)
       :precision binary64
       (* c (/ (fma -0.375 (/ (* a c) (* b b)) -0.5) b)))
      double code(double a, double b, double c) {
      	return c * (fma(-0.375, ((a * c) / (b * b)), -0.5) / b);
      }
      
      function code(a, b, c)
      	return Float64(c * Float64(fma(-0.375, Float64(Float64(a * c) / Float64(b * b)), -0.5) / b))
      end
      
      code[a_, b_, c_] := N[(c * N[(N[(-0.375 * N[(N[(a * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      c \cdot \frac{\mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{b}
      \end{array}
      
      Derivation
      1. Initial program 19.0%

        \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
      2. Add Preprocessing
      3. Taylor expanded in c around 0

        \[\leadsto \color{blue}{c \cdot \left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{3}} - \frac{1}{2} \cdot \frac{1}{b}\right)} \]
      4. Step-by-step derivation
        1. sub-negN/A

          \[\leadsto c \cdot \color{blue}{\left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{3}} + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)\right)} \]
        2. distribute-lft-inN/A

          \[\leadsto \color{blue}{c \cdot \left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{3}}\right) + c \cdot \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)} \]
        3. associate-*r/N/A

          \[\leadsto c \cdot \color{blue}{\frac{\frac{-3}{8} \cdot \left(a \cdot c\right)}{{b}^{3}}} + c \cdot \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right) \]
        4. associate-*r*N/A

          \[\leadsto c \cdot \frac{\color{blue}{\left(\frac{-3}{8} \cdot a\right) \cdot c}}{{b}^{3}} + c \cdot \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right) \]
        5. associate-*l/N/A

          \[\leadsto c \cdot \color{blue}{\left(\frac{\frac{-3}{8} \cdot a}{{b}^{3}} \cdot c\right)} + c \cdot \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right) \]
        6. associate-*r/N/A

          \[\leadsto c \cdot \left(\color{blue}{\left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}}\right)} \cdot c\right) + c \cdot \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right) \]
        7. distribute-lft-inN/A

          \[\leadsto \color{blue}{c \cdot \left(\left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}}\right) \cdot c + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)\right)} \]
        8. lower-*.f64N/A

          \[\leadsto \color{blue}{c \cdot \left(\left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}}\right) \cdot c + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)\right)} \]
        9. associate-*r/N/A

          \[\leadsto c \cdot \left(\color{blue}{\frac{\frac{-3}{8} \cdot a}{{b}^{3}}} \cdot c + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)\right) \]
        10. associate-*l/N/A

          \[\leadsto c \cdot \left(\color{blue}{\frac{\left(\frac{-3}{8} \cdot a\right) \cdot c}{{b}^{3}}} + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)\right) \]
        11. associate-*r*N/A

          \[\leadsto c \cdot \left(\frac{\color{blue}{\frac{-3}{8} \cdot \left(a \cdot c\right)}}{{b}^{3}} + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)\right) \]
        12. associate-*r/N/A

          \[\leadsto c \cdot \left(\color{blue}{\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{3}}} + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)\right) \]
        13. *-commutativeN/A

          \[\leadsto c \cdot \left(\color{blue}{\frac{a \cdot c}{{b}^{3}} \cdot \frac{-3}{8}} + \left(\mathsf{neg}\left(\frac{1}{2} \cdot \frac{1}{b}\right)\right)\right) \]
      5. Applied rewrites95.1%

        \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(a, \frac{c}{b \cdot \left(b \cdot b\right)} \cdot -0.375, \frac{-0.5}{b}\right)} \]
      6. Taylor expanded in b around inf

        \[\leadsto c \cdot \frac{\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{2}} - \frac{1}{2}}{\color{blue}{b}} \]
      7. Step-by-step derivation
        1. Applied rewrites95.1%

          \[\leadsto c \cdot \frac{\mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{\color{blue}{b}} \]
        2. Add Preprocessing

        Alternative 10: 90.2% accurate, 2.9× speedup?

        \[\begin{array}{l} \\ \frac{c}{b} \cdot -0.5 \end{array} \]
        (FPCore (a b c) :precision binary64 (* (/ c b) -0.5))
        double code(double a, double b, double c) {
        	return (c / b) * -0.5;
        }
        
        real(8) function code(a, b, c)
            real(8), intent (in) :: a
            real(8), intent (in) :: b
            real(8), intent (in) :: c
            code = (c / b) * (-0.5d0)
        end function
        
        public static double code(double a, double b, double c) {
        	return (c / b) * -0.5;
        }
        
        def code(a, b, c):
        	return (c / b) * -0.5
        
        function code(a, b, c)
        	return Float64(Float64(c / b) * -0.5)
        end
        
        function tmp = code(a, b, c)
        	tmp = (c / b) * -0.5;
        end
        
        code[a_, b_, c_] := N[(N[(c / b), $MachinePrecision] * -0.5), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \frac{c}{b} \cdot -0.5
        \end{array}
        
        Derivation
        1. Initial program 19.0%

          \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
        2. Add Preprocessing
        3. Taylor expanded in b around inf

          \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b}} \]
        4. Step-by-step derivation
          1. lower-*.f64N/A

            \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b}} \]
          2. lower-/.f6489.7

            \[\leadsto -0.5 \cdot \color{blue}{\frac{c}{b}} \]
        5. Applied rewrites89.7%

          \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
        6. Final simplification89.7%

          \[\leadsto \frac{c}{b} \cdot -0.5 \]
        7. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2024221 
        (FPCore (a b c)
          :name "Cubic critical, wide range"
          :precision binary64
          :pre (and (and (and (< 4.930380657631324e-32 a) (< a 2.028240960365167e+31)) (and (< 4.930380657631324e-32 b) (< b 2.028240960365167e+31))) (and (< 4.930380657631324e-32 c) (< c 2.028240960365167e+31)))
          (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))