Cubic critical, medium range

Percentage Accurate: 31.5% → 99.4%
Time: 13.3s
Alternatives: 8
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 8 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: 31.5% 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: 99.4% accurate, 0.7× speedup?

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

\\
\frac{c \cdot \frac{a \cdot -3}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}}}{a \cdot 3}
\end{array}
Derivation
  1. Initial program 29.8%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \sqrt{\mathsf{fma}\left(b, b, a \cdot \color{blue}{\left(\left(\mathsf{neg}\left(3\right)\right) \cdot c\right)}\right)}}{3 \cdot a} \]
    15. metadata-eval29.9

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, a \cdot \left(\color{blue}{-3} \cdot c\right)\right)}}{3 \cdot a} \]
  4. Applied rewrites29.9%

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(b, b, a \cdot \left(-3 \cdot c\right)\right)}}}{3 \cdot a} \]
  5. Applied rewrites99.4%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\frac{b \cdot b - b \cdot b}{\left(\mathsf{neg}\left(b\right)\right) - \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}} - \frac{c \cdot \left(a \cdot -3\right)}{\color{blue}{\left(\mathsf{neg}\left(b\right)\right)} - \sqrt{c \cdot \left(a \cdot -3\right) + b \cdot b}}}{3 \cdot a} \]
  7. Applied rewrites99.4%

    \[\leadsto \frac{\color{blue}{\left(-c\right) \cdot \frac{a \cdot -3}{\left(-b\right) - \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}}}}{3 \cdot a} \]
  8. Final simplification99.4%

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

Alternative 2: 99.3% accurate, 0.8× speedup?

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

\\
\frac{c \cdot \left(a \cdot 3\right)}{\left(\left(-b\right) - \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}\right) \cdot \left(a \cdot 3\right)}
\end{array}
Derivation
  1. Initial program 29.8%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \sqrt{\mathsf{fma}\left(b, b, a \cdot \color{blue}{\left(\left(\mathsf{neg}\left(3\right)\right) \cdot c\right)}\right)}}{3 \cdot a} \]
    15. metadata-eval29.9

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, a \cdot \left(\color{blue}{-3} \cdot c\right)\right)}}{3 \cdot a} \]
  4. Applied rewrites29.9%

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(b, b, a \cdot \left(-3 \cdot c\right)\right)}}}{3 \cdot a} \]
  5. Applied rewrites99.4%

    \[\leadsto \frac{\color{blue}{\frac{b \cdot b - b \cdot b}{\left(-b\right) - \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}} - \frac{c \cdot \left(a \cdot -3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}}}}{3 \cdot a} \]
  6. Step-by-step derivation
    1. Applied rewrites99.4%

      \[\leadsto \color{blue}{\frac{c \cdot \left(a \cdot 3\right)}{\left(a \cdot 3\right) \cdot \left(\left(-b\right) - \sqrt{\mathsf{fma}\left(c, a \cdot -3, b \cdot b\right)}\right)}} \]
    2. Final simplification99.4%

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

    Alternative 3: 90.6% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(\frac{a \cdot \left(c \cdot -0.375\right)}{b \cdot \left(b \cdot b\right)}, c, \frac{c \cdot -0.5}{b}\right) \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (fma (/ (* a (* c -0.375)) (* b (* b b))) c (/ (* c -0.5) b)))
    double code(double a, double b, double c) {
    	return fma(((a * (c * -0.375)) / (b * (b * b))), c, ((c * -0.5) / b));
    }
    
    function code(a, b, c)
    	return fma(Float64(Float64(a * Float64(c * -0.375)) / Float64(b * Float64(b * b))), c, Float64(Float64(c * -0.5) / b))
    end
    
    code[a_, b_, c_] := N[(N[(N[(a * N[(c * -0.375), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * c + N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \mathsf{fma}\left(\frac{a \cdot \left(c \cdot -0.375\right)}{b \cdot \left(b \cdot b\right)}, c, \frac{c \cdot -0.5}{b}\right)
    \end{array}
    
    Derivation
    1. Initial program 29.8%

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

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

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

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

      \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(a, \frac{c}{b \cdot \left(b \cdot b\right)} \cdot -0.375, \frac{-0.5}{b}\right)} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(a \cdot \left(\frac{c}{b \cdot \left(b \cdot b\right)} \cdot \frac{-3}{8}\right), c, \frac{-1}{2} \cdot \frac{c}{b}\right)} \]
    7. Applied rewrites92.6%

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

    Alternative 4: 90.6% 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 29.8%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    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 rewrites92.6%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(a, \frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot b}, c \cdot -0.5\right)}{b}} \]
    6. Final simplification92.6%

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

    Alternative 5: 90.6% accurate, 1.1× speedup?

    \[\begin{array}{l} \\ \frac{c \cdot \mathsf{fma}\left(-0.375, a \cdot \frac{c}{b \cdot b}, -0.5\right)}{b} \end{array} \]
    (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(a * Float64(c / Float64(b * b))), -0.5)) / b)
    end
    
    code[a_, b_, c_] := N[(N[(c * N[(-0.375 * N[(a * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{c \cdot \mathsf{fma}\left(-0.375, a \cdot \frac{c}{b \cdot b}, -0.5\right)}{b}
    \end{array}
    
    Derivation
    1. Initial program 29.8%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    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 rewrites92.6%

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

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

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

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

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

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

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

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

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

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

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

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

    Alternative 6: 90.3% accurate, 1.1× speedup?

    \[\begin{array}{l} \\ c \cdot \frac{\mathsf{fma}\left(-0.375, \frac{c \cdot a}{b \cdot b}, -0.5\right)}{b} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (* c (/ (fma -0.375 (/ (* c a) (* b b)) -0.5) b)))
    double code(double a, double b, double c) {
    	return c * (fma(-0.375, ((c * a) / (b * b)), -0.5) / b);
    }
    
    function code(a, b, c)
    	return Float64(c * Float64(fma(-0.375, Float64(Float64(c * a) / Float64(b * b)), -0.5) / b))
    end
    
    code[a_, b_, c_] := N[(c * N[(N[(-0.375 * N[(N[(c * a), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    c \cdot \frac{\mathsf{fma}\left(-0.375, \frac{c \cdot a}{b \cdot b}, -0.5\right)}{b}
    \end{array}
    
    Derivation
    1. Initial program 29.8%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto c \cdot \frac{\mathsf{fma}\left(-0.375, \frac{a \cdot c}{\color{blue}{b \cdot b}}, -0.5\right)}{b} \]
    8. Applied rewrites92.3%

      \[\leadsto c \cdot \color{blue}{\frac{\mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{b}} \]
    9. Final simplification92.3%

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

    Alternative 7: 81.2% 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 29.8%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    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-/.f6483.0

        \[\leadsto -0.5 \cdot \color{blue}{\frac{c}{b}} \]
    5. Applied rewrites83.0%

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

    Alternative 8: 3.2% 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 29.8%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(\mathsf{neg}\left(b\right)\right) + \sqrt{\mathsf{fma}\left(b, b, a \cdot \color{blue}{\left(\left(\mathsf{neg}\left(3\right)\right) \cdot c\right)}\right)}}{3 \cdot a} \]
      15. metadata-eval29.9

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, a \cdot \left(\color{blue}{-3} \cdot c\right)\right)}}{3 \cdot a} \]
    4. Applied rewrites29.9%

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(b, b, a \cdot \left(-3 \cdot c\right)\right)}}}{3 \cdot a} \]
    5. Applied rewrites31.8%

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

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

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

        \[\leadsto \frac{b}{a} \cdot \color{blue}{0} \]
      3. mul0-rgt3.2

        \[\leadsto \color{blue}{0} \]
    8. Applied rewrites3.2%

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

    Reproduce

    ?
    herbie shell --seed 2024214 
    (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)))