Cubic critical, wide range

Percentage Accurate: 17.8% → 97.5%
Time: 7.4s
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: 17.8% 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: 97.5% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \frac{6.328125}{{b}^{6}} \cdot \left({c}^{4} \cdot {a}^{4}\right), \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/
  (fma
   (* -0.5625 (* a a))
   (* (/ c (* b b)) (/ (* c c) (* b b)))
   (fma
    (/ -0.16666666666666666 a)
    (* (/ 6.328125 (pow b 6.0)) (* (pow c 4.0) (pow a 4.0)))
    (fma (/ (* -0.375 a) b) (/ (* c c) b) (* -0.5 c))))
  b))
double code(double a, double b, double c) {
	return fma((-0.5625 * (a * a)), ((c / (b * b)) * ((c * c) / (b * b))), fma((-0.16666666666666666 / a), ((6.328125 / pow(b, 6.0)) * (pow(c, 4.0) * pow(a, 4.0))), fma(((-0.375 * a) / b), ((c * c) / b), (-0.5 * c)))) / b;
}
function code(a, b, c)
	return Float64(fma(Float64(-0.5625 * Float64(a * a)), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), fma(Float64(-0.16666666666666666 / a), Float64(Float64(6.328125 / (b ^ 6.0)) * Float64((c ^ 4.0) * (a ^ 4.0))), fma(Float64(Float64(-0.375 * a) / b), Float64(Float64(c * c) / b), Float64(-0.5 * c)))) / b)
end
code[a_, b_, c_] := N[(N[(N[(-0.5625 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-0.16666666666666666 / a), $MachinePrecision] * N[(N[(6.328125 / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] * N[(N[Power[c, 4.0], $MachinePrecision] * N[Power[a, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(-0.375 * a), $MachinePrecision] / b), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / b), $MachinePrecision] + N[(-0.5 * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}

\\
\frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \frac{6.328125}{{b}^{6}} \cdot \left({c}^{4} \cdot {a}^{4}\right), \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b}
\end{array}
Derivation
  1. Initial program 23.0%

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

    \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
  4. Applied rewrites95.7%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{{c}^{3}}{{b}^{4}}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b}} \]
  5. Step-by-step derivation
    1. Applied rewrites95.7%

      \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b} \]
    2. Final simplification95.7%

      \[\leadsto \frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \frac{6.328125}{{b}^{6}} \cdot \left({c}^{4} \cdot {a}^{4}\right), \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b} \]
    3. Add Preprocessing

    Alternative 2: 97.5% accurate, 0.2× speedup?

    \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\mathsf{fma}\left(\frac{\left(c \cdot a\right) \cdot \left(c \cdot a\right)}{{b}^{6}}, -1.0546875, \frac{-0.375}{b \cdot b}\right) \cdot a, c, -0.5\right) \cdot c\right)}{b} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (/
      (fma
       (* -0.5625 (* a a))
       (* (/ c (* b b)) (/ (* c c) (* b b)))
       (*
        (fma
         (*
          (fma (/ (* (* c a) (* c a)) (pow b 6.0)) -1.0546875 (/ -0.375 (* b b)))
          a)
         c
         -0.5)
        c))
      b))
    double code(double a, double b, double c) {
    	return fma((-0.5625 * (a * a)), ((c / (b * b)) * ((c * c) / (b * b))), (fma((fma((((c * a) * (c * a)) / pow(b, 6.0)), -1.0546875, (-0.375 / (b * b))) * a), c, -0.5) * c)) / b;
    }
    
    function code(a, b, c)
    	return Float64(fma(Float64(-0.5625 * Float64(a * a)), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), Float64(fma(Float64(fma(Float64(Float64(Float64(c * a) * Float64(c * a)) / (b ^ 6.0)), -1.0546875, Float64(-0.375 / Float64(b * b))) * a), c, -0.5) * c)) / b)
    end
    
    code[a_, b_, c_] := N[(N[(N[(-0.5625 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(N[(N[(N[(c * a), $MachinePrecision] * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] * -1.0546875 + N[(-0.375 / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision] * c + -0.5), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\mathsf{fma}\left(\frac{\left(c \cdot a\right) \cdot \left(c \cdot a\right)}{{b}^{6}}, -1.0546875, \frac{-0.375}{b \cdot b}\right) \cdot a, c, -0.5\right) \cdot c\right)}{b}
    \end{array}
    
    Derivation
    1. Initial program 23.0%

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

      \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
    4. Applied rewrites95.7%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{{c}^{3}}{{b}^{4}}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b}} \]
    5. Step-by-step derivation
      1. Applied rewrites95.7%

        \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b} \]
      2. Taylor expanded in c around 0

        \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{-9}{16}, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, c \cdot \left(c \cdot \left(\frac{-135}{128} \cdot \frac{{a}^{3} \cdot {c}^{2}}{{b}^{6}} + \frac{-3}{8} \cdot \frac{a}{{b}^{2}}\right) - \frac{1}{2}\right)\right)}{b} \]
      3. Step-by-step derivation
        1. Applied rewrites95.7%

          \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\mathsf{fma}\left(\frac{-0.375}{b}, \frac{a}{b}, \left(-1.0546875 \cdot {a}^{3}\right) \cdot \left(c \cdot \frac{c}{{b}^{6}}\right)\right), c, -0.5\right) \cdot c\right)}{b} \]
        2. Taylor expanded in a around 0

          \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{-9}{16}, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(a \cdot \left(\frac{-135}{128} \cdot \frac{{a}^{2} \cdot {c}^{2}}{{b}^{6}} - \frac{3}{8} \cdot \frac{1}{{b}^{2}}\right), c, \frac{-1}{2}\right) \cdot c\right)}{b} \]
        3. Step-by-step derivation
          1. Applied rewrites95.7%

            \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\mathsf{fma}\left(\frac{\left(c \cdot a\right) \cdot \left(c \cdot a\right)}{{b}^{6}}, -1.0546875, \frac{-0.375}{b \cdot b}\right) \cdot a, c, -0.5\right) \cdot c\right)}{b} \]
          2. Final simplification95.7%

            \[\leadsto \frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\mathsf{fma}\left(\frac{\left(c \cdot a\right) \cdot \left(c \cdot a\right)}{{b}^{6}}, -1.0546875, \frac{-0.375}{b \cdot b}\right) \cdot a, c, -0.5\right) \cdot c\right)}{b} \]
          3. Add Preprocessing

          Alternative 3: 96.8% accurate, 0.5× speedup?

          \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\frac{a}{b \cdot b} \cdot -0.375, c, -0.5\right) \cdot c\right)}{b} \end{array} \]
          (FPCore (a b c)
           :precision binary64
           (/
            (fma
             (* -0.5625 (* a a))
             (* (/ c (* b b)) (/ (* c c) (* b b)))
             (* (fma (* (/ a (* b b)) -0.375) c -0.5) c))
            b))
          double code(double a, double b, double c) {
          	return fma((-0.5625 * (a * a)), ((c / (b * b)) * ((c * c) / (b * b))), (fma(((a / (b * b)) * -0.375), c, -0.5) * c)) / b;
          }
          
          function code(a, b, c)
          	return Float64(fma(Float64(-0.5625 * Float64(a * a)), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), Float64(fma(Float64(Float64(a / Float64(b * b)) * -0.375), c, -0.5) * c)) / b)
          end
          
          code[a_, b_, c_] := N[(N[(N[(-0.5625 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * -0.375), $MachinePrecision] * c + -0.5), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\frac{a}{b \cdot b} \cdot -0.375, c, -0.5\right) \cdot c\right)}{b}
          \end{array}
          
          Derivation
          1. Initial program 23.0%

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

            \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
          4. Applied rewrites95.7%

            \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{{c}^{3}}{{b}^{4}}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b}} \]
          5. Step-by-step derivation
            1. Applied rewrites95.7%

              \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b} \]
            2. Taylor expanded in c around 0

              \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{-9}{16}, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, c \cdot \left(c \cdot \left(\frac{-135}{128} \cdot \frac{{a}^{3} \cdot {c}^{2}}{{b}^{6}} + \frac{-3}{8} \cdot \frac{a}{{b}^{2}}\right) - \frac{1}{2}\right)\right)}{b} \]
            3. Step-by-step derivation
              1. Applied rewrites95.7%

                \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\mathsf{fma}\left(\frac{-0.375}{b}, \frac{a}{b}, \left(-1.0546875 \cdot {a}^{3}\right) \cdot \left(c \cdot \frac{c}{{b}^{6}}\right)\right), c, -0.5\right) \cdot c\right)}{b} \]
              2. Taylor expanded in a around 0

                \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{-9}{16}, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\frac{-3}{8} \cdot \frac{a}{{b}^{2}}, c, \frac{-1}{2}\right) \cdot c\right)}{b} \]
              3. Step-by-step derivation
                1. Applied rewrites94.7%

                  \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\frac{a}{b \cdot b} \cdot -0.375, c, -0.5\right) \cdot c\right)}{b} \]
                2. Final simplification94.7%

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

                Alternative 4: 96.8% accurate, 0.6× speedup?

                \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(\frac{\frac{\mathsf{fma}\left(\left(\frac{a}{b \cdot b} \cdot c\right) \cdot a, -0.5625, -0.375 \cdot a\right)}{b}}{b}, c, -0.5\right) \cdot c}{b} \end{array} \]
                (FPCore (a b c)
                 :precision binary64
                 (/
                  (*
                   (fma
                    (/ (/ (fma (* (* (/ a (* b b)) c) a) -0.5625 (* -0.375 a)) b) b)
                    c
                    -0.5)
                   c)
                  b))
                double code(double a, double b, double c) {
                	return (fma(((fma((((a / (b * b)) * c) * a), -0.5625, (-0.375 * a)) / b) / b), c, -0.5) * c) / b;
                }
                
                function code(a, b, c)
                	return Float64(Float64(fma(Float64(Float64(fma(Float64(Float64(Float64(a / Float64(b * b)) * c) * a), -0.5625, Float64(-0.375 * a)) / b) / b), c, -0.5) * c) / b)
                end
                
                code[a_, b_, c_] := N[(N[(N[(N[(N[(N[(N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision] * a), $MachinePrecision] * -0.5625 + N[(-0.375 * a), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision] / b), $MachinePrecision] * c + -0.5), $MachinePrecision] * c), $MachinePrecision] / b), $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                \frac{\mathsf{fma}\left(\frac{\frac{\mathsf{fma}\left(\left(\frac{a}{b \cdot b} \cdot c\right) \cdot a, -0.5625, -0.375 \cdot a\right)}{b}}{b}, c, -0.5\right) \cdot c}{b}
                \end{array}
                
                Derivation
                1. Initial program 23.0%

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

                  \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
                4. Applied rewrites95.7%

                  \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{{c}^{3}}{{b}^{4}}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b}} \]
                5. Taylor expanded in c around 0

                  \[\leadsto \frac{c \cdot \left(c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot c}{{b}^{4}} + \frac{-3}{8} \cdot \frac{a}{{b}^{2}}\right) - \frac{1}{2}\right)}{b} \]
                6. Step-by-step derivation
                  1. Applied rewrites94.6%

                    \[\leadsto \frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{-0.375}{b}, \frac{a}{b}, \frac{\left(\left(a \cdot a\right) \cdot c\right) \cdot -0.5625}{{b}^{4}}\right), c, -0.5\right) \cdot c}{b} \]
                  2. Taylor expanded in b around inf

                    \[\leadsto \frac{\mathsf{fma}\left(\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot c}{{b}^{2}} + \frac{-3}{8} \cdot a}{{b}^{2}}, c, \frac{-1}{2}\right) \cdot c}{b} \]
                  3. Step-by-step derivation
                    1. Applied rewrites94.6%

                      \[\leadsto \frac{\mathsf{fma}\left(\frac{\frac{\mathsf{fma}\left(a \cdot \left(c \cdot \frac{a}{b \cdot b}\right), -0.5625, -0.375 \cdot a\right)}{b}}{b}, c, -0.5\right) \cdot c}{b} \]
                    2. Final simplification94.6%

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

                    Alternative 5: 96.5% accurate, 0.6× speedup?

                    \[\begin{array}{l} \\ \frac{0.3333333333333333}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{0.375 \cdot a}{b}, \frac{c}{b}, 0.5\right)}{b}, a, -0.6666666666666666 \cdot \frac{b}{c}\right)} \end{array} \]
                    (FPCore (a b c)
                     :precision binary64
                     (/
                      0.3333333333333333
                      (fma
                       (/ (fma (/ (* 0.375 a) b) (/ c b) 0.5) b)
                       a
                       (* -0.6666666666666666 (/ b c)))))
                    double code(double a, double b, double c) {
                    	return 0.3333333333333333 / fma((fma(((0.375 * a) / b), (c / b), 0.5) / b), a, (-0.6666666666666666 * (b / c)));
                    }
                    
                    function code(a, b, c)
                    	return Float64(0.3333333333333333 / fma(Float64(fma(Float64(Float64(0.375 * a) / b), Float64(c / b), 0.5) / b), a, Float64(-0.6666666666666666 * Float64(b / c))))
                    end
                    
                    code[a_, b_, c_] := N[(0.3333333333333333 / N[(N[(N[(N[(N[(0.375 * a), $MachinePrecision] / b), $MachinePrecision] * N[(c / b), $MachinePrecision] + 0.5), $MachinePrecision] / b), $MachinePrecision] * a + N[(-0.6666666666666666 * N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \frac{0.3333333333333333}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{0.375 \cdot a}{b}, \frac{c}{b}, 0.5\right)}{b}, a, -0.6666666666666666 \cdot \frac{b}{c}\right)}
                    \end{array}
                    
                    Derivation
                    1. Initial program 23.0%

                      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
                    2. Add Preprocessing
                    3. Step-by-step derivation
                      1. lift-/.f64N/A

                        \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}} \]
                      2. clear-numN/A

                        \[\leadsto \color{blue}{\frac{1}{\frac{3 \cdot a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                      3. lift-*.f64N/A

                        \[\leadsto \frac{1}{\frac{\color{blue}{3 \cdot a}}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}} \]
                      4. associate-/l*N/A

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

                        \[\leadsto \color{blue}{\frac{\frac{1}{3}}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                      6. lower-/.f64N/A

                        \[\leadsto \color{blue}{\frac{\frac{1}{3}}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                      7. metadata-evalN/A

                        \[\leadsto \frac{\color{blue}{\frac{1}{3}}}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}} \]
                      8. lower-/.f6423.0

                        \[\leadsto \frac{0.3333333333333333}{\color{blue}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                      9. lift-+.f64N/A

                        \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\color{blue}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                      10. +-commutativeN/A

                        \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(-b\right)}}} \]
                      11. lift-neg.f64N/A

                        \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \color{blue}{\left(\mathsf{neg}\left(b\right)\right)}}} \]
                      12. unsub-negN/A

                        \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
                      13. lower--.f6423.0

                        \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
                    4. Applied rewrites23.0%

                      \[\leadsto \color{blue}{\frac{0.3333333333333333}{\frac{a}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b}}} \]
                    5. Taylor expanded in a around 0

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

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

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

                        \[\leadsto \frac{\frac{1}{3}}{\color{blue}{\mathsf{fma}\left(-1 \cdot \left(a \cdot \left(\frac{-3}{4} \cdot \frac{c}{{b}^{3}} + \frac{3}{8} \cdot \frac{c}{{b}^{3}}\right)\right) + \frac{1}{2} \cdot \frac{1}{b}, a, \frac{-2}{3} \cdot \frac{b}{c}\right)}} \]
                    7. Applied rewrites94.5%

                      \[\leadsto \frac{0.3333333333333333}{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(0.375 \cdot \frac{c}{{b}^{3}}, a, \frac{0.5}{b}\right), a, \frac{b}{c} \cdot -0.6666666666666666\right)}} \]
                    8. Taylor expanded in b around inf

                      \[\leadsto \frac{\frac{1}{3}}{\mathsf{fma}\left(\frac{\frac{1}{2} + \frac{3}{8} \cdot \frac{a \cdot c}{{b}^{2}}}{b}, a, \frac{b}{c} \cdot \frac{-2}{3}\right)} \]
                    9. Step-by-step derivation
                      1. Applied rewrites94.5%

                        \[\leadsto \frac{0.3333333333333333}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{0.375 \cdot a}{b}, \frac{c}{b}, 0.5\right)}{b}, a, \frac{b}{c} \cdot -0.6666666666666666\right)} \]
                      2. Final simplification94.5%

                        \[\leadsto \frac{0.3333333333333333}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{0.375 \cdot a}{b}, \frac{c}{b}, 0.5\right)}{b}, a, -0.6666666666666666 \cdot \frac{b}{c}\right)} \]
                      3. Add Preprocessing

                      Alternative 6: 95.2% accurate, 0.9× speedup?

                      \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)}{b} \end{array} \]
                      (FPCore (a b c)
                       :precision binary64
                       (/ (fma (/ (* -0.375 a) b) (/ (* c c) b) (* -0.5 c)) b))
                      double code(double a, double b, double c) {
                      	return fma(((-0.375 * a) / b), ((c * c) / b), (-0.5 * c)) / b;
                      }
                      
                      function code(a, b, c)
                      	return Float64(fma(Float64(Float64(-0.375 * a) / b), Float64(Float64(c * c) / b), Float64(-0.5 * c)) / b)
                      end
                      
                      code[a_, b_, c_] := N[(N[(N[(N[(-0.375 * a), $MachinePrecision] / b), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / b), $MachinePrecision] + N[(-0.5 * c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \frac{\mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)}{b}
                      \end{array}
                      
                      Derivation
                      1. Initial program 23.0%

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

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

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

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

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

                          \[\leadsto \frac{\frac{\color{blue}{\left(\frac{-3}{8} \cdot a\right) \cdot {c}^{2}}}{b \cdot b} + \frac{-1}{2} \cdot c}{b} \]
                        6. times-fracN/A

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

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

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

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

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

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

                          \[\leadsto \frac{\mathsf{fma}\left(\frac{\frac{-3}{8} \cdot a}{b}, \frac{\color{blue}{c \cdot c}}{b}, \frac{-1}{2} \cdot c\right)}{b} \]
                        13. lower-*.f6492.5

                          \[\leadsto \frac{\mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, \color{blue}{-0.5 \cdot c}\right)}{b} \]
                      5. Applied rewrites92.5%

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

                      Alternative 7: 95.2% accurate, 1.1× speedup?

                      \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(\frac{a}{b \cdot b} \cdot -0.375, c, -0.5\right) \cdot c}{b} \end{array} \]
                      (FPCore (a b c)
                       :precision binary64
                       (/ (* (fma (* (/ a (* b b)) -0.375) c -0.5) c) b))
                      double code(double a, double b, double c) {
                      	return (fma(((a / (b * b)) * -0.375), c, -0.5) * c) / b;
                      }
                      
                      function code(a, b, c)
                      	return Float64(Float64(fma(Float64(Float64(a / Float64(b * b)) * -0.375), c, -0.5) * c) / b)
                      end
                      
                      code[a_, b_, c_] := N[(N[(N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * -0.375), $MachinePrecision] * c + -0.5), $MachinePrecision] * c), $MachinePrecision] / b), $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \frac{\mathsf{fma}\left(\frac{a}{b \cdot b} \cdot -0.375, c, -0.5\right) \cdot c}{b}
                      \end{array}
                      
                      Derivation
                      1. Initial program 23.0%

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

                        \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
                      4. Applied rewrites95.7%

                        \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{{c}^{3}}{{b}^{4}}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b}} \]
                      5. Taylor expanded in c around 0

                        \[\leadsto \frac{c \cdot \left(c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot c}{{b}^{4}} + \frac{-3}{8} \cdot \frac{a}{{b}^{2}}\right) - \frac{1}{2}\right)}{b} \]
                      6. Step-by-step derivation
                        1. Applied rewrites94.6%

                          \[\leadsto \frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{-0.375}{b}, \frac{a}{b}, \frac{\left(\left(a \cdot a\right) \cdot c\right) \cdot -0.5625}{{b}^{4}}\right), c, -0.5\right) \cdot c}{b} \]
                        2. Taylor expanded in a around 0

                          \[\leadsto \frac{\mathsf{fma}\left(\frac{-3}{8} \cdot \frac{a}{{b}^{2}}, c, \frac{-1}{2}\right) \cdot c}{b} \]
                        3. Step-by-step derivation
                          1. Applied rewrites92.5%

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

                          Alternative 8: 94.9% accurate, 1.1× speedup?

                          \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(\frac{a}{b \cdot b} \cdot c, -0.375, -0.5\right)}{b} \cdot c \end{array} \]
                          (FPCore (a b c)
                           :precision binary64
                           (* (/ (fma (* (/ a (* b b)) c) -0.375 -0.5) b) c))
                          double code(double a, double b, double c) {
                          	return (fma(((a / (b * b)) * c), -0.375, -0.5) / b) * c;
                          }
                          
                          function code(a, b, c)
                          	return Float64(Float64(fma(Float64(Float64(a / Float64(b * b)) * c), -0.375, -0.5) / b) * c)
                          end
                          
                          code[a_, b_, c_] := N[(N[(N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision] * -0.375 + -0.5), $MachinePrecision] / b), $MachinePrecision] * c), $MachinePrecision]
                          
                          \begin{array}{l}
                          
                          \\
                          \frac{\mathsf{fma}\left(\frac{a}{b \cdot b} \cdot c, -0.375, -0.5\right)}{b} \cdot c
                          \end{array}
                          
                          Derivation
                          1. Initial program 23.0%

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

                            \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
                          4. Applied rewrites95.7%

                            \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{{c}^{3}}{{b}^{4}}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b}} \]
                          5. Step-by-step derivation
                            1. Applied rewrites95.7%

                              \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b} \]
                            2. Taylor expanded in c around 0

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

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

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

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

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

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

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

                                \[\leadsto \color{blue}{\left(c \cdot \left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}}\right) - \frac{1}{2} \cdot \frac{1}{b}\right) \cdot c} \]
                            4. Applied rewrites92.2%

                              \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(c \cdot \frac{a}{b \cdot b}, -0.375, -0.5\right)}{b} \cdot c} \]
                            5. Final simplification92.2%

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

                            Alternative 9: 90.4% 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 23.0%

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

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

                                \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b}} \]
                              2. lower-/.f6486.6

                                \[\leadsto -0.5 \cdot \color{blue}{\frac{c}{b}} \]
                            5. Applied rewrites86.6%

                              \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
                            6. Final simplification86.6%

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

                            Alternative 10: 3.3% accurate, 50.0× speedup?

                            \[\begin{array}{l} \\ 0 \end{array} \]
                            (FPCore (a b c) :precision binary64 0.0)
                            double code(double a, double b, double c) {
                            	return 0.0;
                            }
                            
                            real(8) function code(a, b, c)
                                real(8), intent (in) :: a
                                real(8), intent (in) :: b
                                real(8), intent (in) :: c
                                code = 0.0d0
                            end function
                            
                            public static double code(double a, double b, double c) {
                            	return 0.0;
                            }
                            
                            def code(a, b, c):
                            	return 0.0
                            
                            function code(a, b, c)
                            	return 0.0
                            end
                            
                            function tmp = code(a, b, c)
                            	tmp = 0.0;
                            end
                            
                            code[a_, b_, c_] := 0.0
                            
                            \begin{array}{l}
                            
                            \\
                            0
                            \end{array}
                            
                            Derivation
                            1. Initial program 23.0%

                              \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
                            2. Add Preprocessing
                            3. Step-by-step derivation
                              1. lift-/.f64N/A

                                \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}} \]
                              2. clear-numN/A

                                \[\leadsto \color{blue}{\frac{1}{\frac{3 \cdot a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                              3. lift-*.f64N/A

                                \[\leadsto \frac{1}{\frac{\color{blue}{3 \cdot a}}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}} \]
                              4. associate-/l*N/A

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

                                \[\leadsto \color{blue}{\frac{\frac{1}{3}}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                              6. lower-/.f64N/A

                                \[\leadsto \color{blue}{\frac{\frac{1}{3}}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                              7. metadata-evalN/A

                                \[\leadsto \frac{\color{blue}{\frac{1}{3}}}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}} \]
                              8. lower-/.f6423.0

                                \[\leadsto \frac{0.3333333333333333}{\color{blue}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                              9. lift-+.f64N/A

                                \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\color{blue}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
                              10. +-commutativeN/A

                                \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(-b\right)}}} \]
                              11. lift-neg.f64N/A

                                \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \color{blue}{\left(\mathsf{neg}\left(b\right)\right)}}} \]
                              12. unsub-negN/A

                                \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
                              13. lower--.f6423.0

                                \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
                            4. Applied rewrites23.0%

                              \[\leadsto \color{blue}{\frac{0.3333333333333333}{\frac{a}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b}}} \]
                            5. Step-by-step derivation
                              1. lift-/.f64N/A

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

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

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

                                \[\leadsto \frac{\frac{1}{3}}{a} \cdot \color{blue}{\left(\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b\right)} \]
                              5. sub-negN/A

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

                                \[\leadsto \color{blue}{\frac{\frac{1}{3}}{a} \cdot \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + \frac{\frac{1}{3}}{a} \cdot \left(\mathsf{neg}\left(b\right)\right)} \]
                              7. lower-+.f64N/A

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

                                \[\leadsto \color{blue}{\frac{\frac{1}{3}}{a} \cdot \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)}} + \frac{\frac{1}{3}}{a} \cdot \left(\mathsf{neg}\left(b\right)\right) \]
                              9. lower-/.f64N/A

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

                                \[\leadsto \frac{\frac{1}{3}}{a} \cdot \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + \color{blue}{\frac{\frac{1}{3}}{a} \cdot \left(\mathsf{neg}\left(b\right)\right)} \]
                              11. lower-/.f64N/A

                                \[\leadsto \frac{\frac{1}{3}}{a} \cdot \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + \color{blue}{\frac{\frac{1}{3}}{a}} \cdot \left(\mathsf{neg}\left(b\right)\right) \]
                              12. lower-neg.f6422.7

                                \[\leadsto \frac{0.3333333333333333}{a} \cdot \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + \frac{0.3333333333333333}{a} \cdot \color{blue}{\left(-b\right)} \]
                            6. Applied rewrites22.7%

                              \[\leadsto \color{blue}{\frac{0.3333333333333333}{a} \cdot \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + \frac{0.3333333333333333}{a} \cdot \left(-b\right)} \]
                            7. Taylor expanded in a around 0

                              \[\leadsto \color{blue}{\frac{\frac{-1}{3} \cdot b + \frac{1}{3} \cdot b}{a}} \]
                            8. Step-by-step derivation
                              1. distribute-rgt-outN/A

                                \[\leadsto \frac{\color{blue}{b \cdot \left(\frac{-1}{3} + \frac{1}{3}\right)}}{a} \]
                              2. metadata-evalN/A

                                \[\leadsto \frac{b \cdot \color{blue}{0}}{a} \]
                              3. associate-*l/N/A

                                \[\leadsto \color{blue}{\frac{b}{a} \cdot 0} \]
                              4. mul0-rgt3.3

                                \[\leadsto \color{blue}{0} \]
                            9. Applied rewrites3.3%

                              \[\leadsto \color{blue}{0} \]
                            10. Add Preprocessing

                            Reproduce

                            ?
                            herbie shell --seed 2024332 
                            (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)))