Cubic critical, medium range

Percentage Accurate: 31.9% → 99.1%
Time: 11.2s
Alternatives: 7
Speedup: 2.9×

Specification

?
\[\left(\left(1.1102230246251565 \cdot 10^{-16} < a \land a < 9007199254740992\right) \land \left(1.1102230246251565 \cdot 10^{-16} < b \land b < 9007199254740992\right)\right) \land \left(1.1102230246251565 \cdot 10^{-16} < c \land c < 9007199254740992\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \end{array} \]
(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 7 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: 31.9% 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: 99.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \frac{0.3333333333333333}{\frac{a}{\frac{\frac{\left(-a\right) \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/
  0.3333333333333333
  (/
   a
   (/
    (/ (* (- a) (* c (sqrt 27.0))) (sqrt 3.0))
    (+ (sqrt (fma (* -3.0 c) a (* b b))) b)))))
double code(double a, double b, double c) {
	return 0.3333333333333333 / (a / (((-a * (c * sqrt(27.0))) / sqrt(3.0)) / (sqrt(fma((-3.0 * c), a, (b * b))) + b)));
}
function code(a, b, c)
	return Float64(0.3333333333333333 / Float64(a / Float64(Float64(Float64(Float64(-a) * Float64(c * sqrt(27.0))) / sqrt(3.0)) / Float64(sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))) + b))))
end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(a / N[(N[(N[((-a) * N[(c * N[Sqrt[27.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Sqrt[3.0], $MachinePrecision]), $MachinePrecision] / N[(N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.3333333333333333}{\frac{a}{\frac{\frac{\left(-a\right) \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}}
\end{array}
Derivation
  1. Initial program 29.5%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  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-/.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\color{blue}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
    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--.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
  4. Applied rewrites29.5%

    \[\leadsto \color{blue}{\frac{0.3333333333333333}{\frac{a}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b}}} \]
  5. Applied rewrites29.8%

    \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b} - \frac{b \cdot b}{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b}}}} \]
  6. Applied rewrites29.6%

    \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\frac{\frac{\mathsf{fma}\left(\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right), b, {\left(\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)\right)}^{1.5}\right) - \left(\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b\right) \cdot \left(b \cdot b\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}}} \]
  7. Taylor expanded in a around -inf

    \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\frac{\color{blue}{-1 \cdot \frac{a \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
  8. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\frac{\color{blue}{\mathsf{neg}\left(\frac{a \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}\right)}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
    2. lower-neg.f64N/A

      \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\frac{\color{blue}{-\frac{a \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
    3. lower-/.f64N/A

      \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\frac{-\color{blue}{\frac{a \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
    4. lower-*.f64N/A

      \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\frac{-\frac{\color{blue}{a \cdot \left(c \cdot \sqrt{27}\right)}}{\sqrt{3}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
    5. lower-*.f64N/A

      \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\frac{-\frac{a \cdot \color{blue}{\left(c \cdot \sqrt{27}\right)}}{\sqrt{3}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
    6. lower-sqrt.f64N/A

      \[\leadsto \frac{\frac{1}{3}}{\frac{a}{\frac{-\frac{a \cdot \left(c \cdot \color{blue}{\sqrt{27}}\right)}{\sqrt{3}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
    7. lower-sqrt.f6499.1

      \[\leadsto \frac{0.3333333333333333}{\frac{a}{\frac{-\frac{a \cdot \left(c \cdot \sqrt{27}\right)}{\color{blue}{\sqrt{3}}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
  9. Applied rewrites99.1%

    \[\leadsto \frac{0.3333333333333333}{\frac{a}{\frac{\color{blue}{-\frac{a \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
  10. Final simplification99.1%

    \[\leadsto \frac{0.3333333333333333}{\frac{a}{\frac{\frac{\left(-a\right) \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}} \]
  11. Add Preprocessing

Alternative 2: 99.0% accurate, 0.3× speedup?

\[\begin{array}{l} \\ {\left(\frac{a}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b} \cdot 0.3333333333333333}\right)}^{-1} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (pow
  (/
   a
   (*
    (/ (fma (* -3.0 a) c 0.0) (+ (sqrt (fma (* -3.0 c) a (* b b))) b))
    0.3333333333333333))
  -1.0))
double code(double a, double b, double c) {
	return pow((a / ((fma((-3.0 * a), c, 0.0) / (sqrt(fma((-3.0 * c), a, (b * b))) + b)) * 0.3333333333333333)), -1.0);
}
function code(a, b, c)
	return Float64(a / Float64(Float64(fma(Float64(-3.0 * a), c, 0.0) / Float64(sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))) + b)) * 0.3333333333333333)) ^ -1.0
end
code[a_, b_, c_] := N[Power[N[(a / N[(N[(N[(N[(-3.0 * a), $MachinePrecision] * c + 0.0), $MachinePrecision] / N[(N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}

\\
{\left(\frac{a}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b} \cdot 0.3333333333333333}\right)}^{-1}
\end{array}
Derivation
  1. Initial program 29.5%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  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-/.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\color{blue}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
    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--.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
  4. Applied rewrites29.5%

    \[\leadsto \color{blue}{\frac{0.3333333333333333}{\frac{a}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b}}} \]
  5. Applied rewrites29.8%

    \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b} - \frac{b \cdot b}{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b}}}} \]
  6. Applied rewrites29.5%

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

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

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

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

      \[\leadsto \frac{1}{\frac{a}{\color{blue}{\frac{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} \cdot \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b \cdot b}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}} \cdot \frac{1}{3}}} \]
  8. Applied rewrites99.0%

    \[\leadsto \frac{1}{\frac{a}{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}} \cdot 0.3333333333333333}} \]
  9. Final simplification99.0%

    \[\leadsto {\left(\frac{a}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b} \cdot 0.3333333333333333}\right)}^{-1} \]
  10. Add Preprocessing

Alternative 3: 90.8% accurate, 0.4× speedup?

\[\begin{array}{l} \\ {\left(\frac{\mathsf{fma}\left(-2, b, 1.5 \cdot \frac{a \cdot c}{b}\right)}{c}\right)}^{-1} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (pow (/ (fma -2.0 b (* 1.5 (/ (* a c) b))) c) -1.0))
double code(double a, double b, double c) {
	return pow((fma(-2.0, b, (1.5 * ((a * c) / b))) / c), -1.0);
}
function code(a, b, c)
	return Float64(fma(-2.0, b, Float64(1.5 * Float64(Float64(a * c) / b))) / c) ^ -1.0
end
code[a_, b_, c_] := N[Power[N[(N[(-2.0 * b + N[(1.5 * N[(N[(a * c), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}

\\
{\left(\frac{\mathsf{fma}\left(-2, b, 1.5 \cdot \frac{a \cdot c}{b}\right)}{c}\right)}^{-1}
\end{array}
Derivation
  1. Initial program 29.5%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  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-/.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\color{blue}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
    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--.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
  4. Applied rewrites29.5%

    \[\leadsto \color{blue}{\frac{0.3333333333333333}{\frac{a}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b}}} \]
  5. Applied rewrites29.8%

    \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b} - \frac{b \cdot b}{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b}}}} \]
  6. Applied rewrites29.5%

    \[\leadsto \color{blue}{\frac{1}{\frac{a}{\left(\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b\right) \cdot 0.3333333333333333}}} \]
  7. Taylor expanded in c around 0

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

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

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

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

      \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(-2, b, \frac{3}{2} \cdot \color{blue}{\frac{a \cdot c}{b}}\right)}{c}} \]
    5. lower-*.f6490.8

      \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(-2, b, 1.5 \cdot \frac{\color{blue}{a \cdot c}}{b}\right)}{c}} \]
  9. Applied rewrites90.8%

    \[\leadsto \frac{1}{\color{blue}{\frac{\mathsf{fma}\left(-2, b, 1.5 \cdot \frac{a \cdot c}{b}\right)}{c}}} \]
  10. Final simplification90.8%

    \[\leadsto {\left(\frac{\mathsf{fma}\left(-2, b, 1.5 \cdot \frac{a \cdot c}{b}\right)}{c}\right)}^{-1} \]
  11. Add Preprocessing

Alternative 4: 90.8% accurate, 0.4× speedup?

\[\begin{array}{l} \\ {\left(\mathsf{fma}\left(-2, \frac{b}{c}, 1.5 \cdot \frac{a}{b}\right)\right)}^{-1} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (pow (fma -2.0 (/ b c) (* 1.5 (/ a b))) -1.0))
double code(double a, double b, double c) {
	return pow(fma(-2.0, (b / c), (1.5 * (a / b))), -1.0);
}
function code(a, b, c)
	return fma(-2.0, Float64(b / c), Float64(1.5 * Float64(a / b))) ^ -1.0
end
code[a_, b_, c_] := N[Power[N[(-2.0 * N[(b / c), $MachinePrecision] + N[(1.5 * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}

\\
{\left(\mathsf{fma}\left(-2, \frac{b}{c}, 1.5 \cdot \frac{a}{b}\right)\right)}^{-1}
\end{array}
Derivation
  1. Initial program 29.5%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  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-/.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\color{blue}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
    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--.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
  4. Applied rewrites29.5%

    \[\leadsto \color{blue}{\frac{0.3333333333333333}{\frac{a}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b}}} \]
  5. Applied rewrites29.8%

    \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b} - \frac{b \cdot b}{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b}}}} \]
  6. Applied rewrites29.5%

    \[\leadsto \color{blue}{\frac{1}{\frac{a}{\left(\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b\right) \cdot 0.3333333333333333}}} \]
  7. Taylor expanded in a around 0

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

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

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

      \[\leadsto \frac{1}{\mathsf{fma}\left(-2, \frac{b}{c}, \color{blue}{\frac{3}{2} \cdot \frac{a}{b}}\right)} \]
    4. lower-/.f6490.8

      \[\leadsto \frac{1}{\mathsf{fma}\left(-2, \frac{b}{c}, 1.5 \cdot \color{blue}{\frac{a}{b}}\right)} \]
  9. Applied rewrites90.8%

    \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(-2, \frac{b}{c}, 1.5 \cdot \frac{a}{b}\right)}} \]
  10. Final simplification90.8%

    \[\leadsto {\left(\mathsf{fma}\left(-2, \frac{b}{c}, 1.5 \cdot \frac{a}{b}\right)\right)}^{-1} \]
  11. Add Preprocessing

Alternative 5: 99.1% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \frac{0.3333333333333333}{\frac{a}{\mathsf{fma}\left(-3 \cdot a, c, 0\right)} \cdot \left(\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b\right)} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/
  0.3333333333333333
  (* (/ a (fma (* -3.0 a) c 0.0)) (+ (sqrt (fma (* -3.0 c) a (* b b))) b))))
double code(double a, double b, double c) {
	return 0.3333333333333333 / ((a / fma((-3.0 * a), c, 0.0)) * (sqrt(fma((-3.0 * c), a, (b * b))) + b));
}
function code(a, b, c)
	return Float64(0.3333333333333333 / Float64(Float64(a / fma(Float64(-3.0 * a), c, 0.0)) * Float64(sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))) + b)))
end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(N[(a / N[(N[(-3.0 * a), $MachinePrecision] * c + 0.0), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.3333333333333333}{\frac{a}{\mathsf{fma}\left(-3 \cdot a, c, 0\right)} \cdot \left(\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b\right)}
\end{array}
Derivation
  1. Initial program 29.5%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  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-/.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\color{blue}{\frac{a}{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
    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--.f6429.5

      \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}}} \]
  4. Applied rewrites29.5%

    \[\leadsto \color{blue}{\frac{0.3333333333333333}{\frac{a}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} - b}}} \]
  5. Applied rewrites30.1%

    \[\leadsto \frac{0.3333333333333333}{\frac{a}{\color{blue}{\frac{1}{\frac{\sqrt{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right)} + b}{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b\right) - b \cdot b}}}}} \]
  6. Applied rewrites99.0%

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

Alternative 6: 90.6% 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 29.5%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  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 rewrites95.8%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{{c}^{3}}{{b}^{4}}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}, \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)\right)\right)}{b}} \]
  5. Step-by-step derivation
    1. Applied rewrites95.8%

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

      \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{-9}{16}, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \frac{-1}{2} \cdot c + a \cdot \left(\frac{-135}{128} \cdot \frac{{a}^{2} \cdot {c}^{4}}{{b}^{6}} + \frac{-3}{8} \cdot \frac{{c}^{2}}{{b}^{2}}\right)\right)}{b} \]
    3. Step-by-step derivation
      1. Applied rewrites95.8%

        \[\leadsto \frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(a, \mathsf{fma}\left(-1.0546875, \frac{\left(a \cdot a\right) \cdot {c}^{4}}{{b}^{6}}, \frac{-0.375}{b} \cdot \frac{c \cdot c}{b}\right), -0.5 \cdot c\right)\right)}{b} \]
      2. Taylor expanded in c around 0

        \[\leadsto \frac{c \cdot \left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{2}} - \frac{1}{2}\right)}{b} \]
      3. Step-by-step derivation
        1. Applied rewrites90.6%

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

        Alternative 7: 81.0% accurate, 2.9× speedup?

        \[\begin{array}{l} \\ -0.5 \cdot \frac{c}{b} \end{array} \]
        (FPCore (a b c) :precision binary64 (* -0.5 (/ c b)))
        double code(double a, double b, double c) {
        	return -0.5 * (c / b);
        }
        
        real(8) function code(a, b, c)
            real(8), intent (in) :: a
            real(8), intent (in) :: b
            real(8), intent (in) :: c
            code = (-0.5d0) * (c / b)
        end function
        
        public static double code(double a, double b, double c) {
        	return -0.5 * (c / b);
        }
        
        def code(a, b, c):
        	return -0.5 * (c / b)
        
        function code(a, b, c)
        	return Float64(-0.5 * Float64(c / b))
        end
        
        function tmp = code(a, b, c)
        	tmp = -0.5 * (c / b);
        end
        
        code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        -0.5 \cdot \frac{c}{b}
        \end{array}
        
        Derivation
        1. Initial program 29.5%

          \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
        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-/.f6482.3

            \[\leadsto -0.5 \cdot \color{blue}{\frac{c}{b}} \]
        5. Applied rewrites82.3%

          \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
        6. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2024298 
        (FPCore (a b c)
          :name "Cubic critical, medium range"
          :precision binary64
          :pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
          (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))