Cubic critical, wide range

Percentage Accurate: 17.9% → 97.5%
Time: 14.3s
Alternatives: 8
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 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: 17.9% 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: 97.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := b \cdot \left(b \cdot b\right)\\ \mathsf{fma}\left(\mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot 6.328125\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot t\_0\right)\right) \cdot \left(a \cdot b\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot t\_0}\right), \frac{a \cdot -0.375}{t\_0}\right), c \cdot c, \frac{c}{b \cdot -2}\right) \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (* b (* b b))))
   (fma
    (fma
     c
     (fma
      (/
       (* (* a (* a (* a a))) (* c 6.328125))
       (* (* (* b b) (* b t_0)) (* a b)))
      -0.16666666666666666
      (/ (* (* a a) -0.5625) (* (* b b) t_0)))
     (/ (* a -0.375) t_0))
    (* c c)
    (/ c (* b -2.0)))))
double code(double a, double b, double c) {
	double t_0 = b * (b * b);
	return fma(fma(c, fma((((a * (a * (a * a))) * (c * 6.328125)) / (((b * b) * (b * t_0)) * (a * b))), -0.16666666666666666, (((a * a) * -0.5625) / ((b * b) * t_0))), ((a * -0.375) / t_0)), (c * c), (c / (b * -2.0)));
}
function code(a, b, c)
	t_0 = Float64(b * Float64(b * b))
	return fma(fma(c, fma(Float64(Float64(Float64(a * Float64(a * Float64(a * a))) * Float64(c * 6.328125)) / Float64(Float64(Float64(b * b) * Float64(b * t_0)) * Float64(a * b))), -0.16666666666666666, Float64(Float64(Float64(a * a) * -0.5625) / Float64(Float64(b * b) * t_0))), Float64(Float64(a * -0.375) / t_0)), Float64(c * c), Float64(c / Float64(b * -2.0)))
end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(c * N[(N[(N[(N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * 6.328125), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(b * b), $MachinePrecision] * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision] * N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666 + N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a * -0.375), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision] + N[(c / N[(b * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot b\right)\\
\mathsf{fma}\left(\mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot 6.328125\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot t\_0\right)\right) \cdot \left(a \cdot b\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot t\_0}\right), \frac{a \cdot -0.375}{t\_0}\right), c \cdot c, \frac{c}{b \cdot -2}\right)
\end{array}
\end{array}
Derivation
  1. Initial program 18.1%

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

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}} + c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2}}{{b}^{5}} + \frac{-1}{6} \cdot \frac{c \cdot \left(\frac{81}{64} \cdot \frac{{a}^{4}}{{b}^{6}} + \frac{81}{16} \cdot \frac{{a}^{4}}{{b}^{6}}\right)}{a \cdot b}\right)\right) - \frac{1}{2} \cdot \frac{1}{b}\right)} \]
  4. Applied rewrites96.9%

    \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(-0.16666666666666666, \frac{\frac{{a}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot c\right)}{a \cdot b}, \frac{\left(a \cdot a\right) \cdot -0.5625}{{b}^{5}}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right)} \]
  5. Applied rewrites97.3%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(6.328125 \cdot c\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)\right) \cdot \left(b \cdot a\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), c \cdot c, \frac{c}{b \cdot -2}\right)} \]
  6. Final simplification97.3%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot 6.328125\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)\right) \cdot \left(a \cdot b\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), c \cdot c, \frac{c}{b \cdot -2}\right) \]
  7. Add Preprocessing

Alternative 2: 97.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := b \cdot \left(b \cdot b\right)\\ \mathsf{fma}\left(\frac{-0.5}{b}, c, \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot 6.328125\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot t\_0\right)\right) \cdot \left(a \cdot b\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot t\_0}\right), \frac{a \cdot -0.375}{t\_0}\right) \cdot \left(c \cdot c\right)\right) \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (* b (* b b))))
   (fma
    (/ -0.5 b)
    c
    (*
     (fma
      c
      (fma
       (/
        (* (* a (* a (* a a))) (* c 6.328125))
        (* (* (* b b) (* b t_0)) (* a b)))
       -0.16666666666666666
       (/ (* (* a a) -0.5625) (* (* b b) t_0)))
      (/ (* a -0.375) t_0))
     (* c c)))))
double code(double a, double b, double c) {
	double t_0 = b * (b * b);
	return fma((-0.5 / b), c, (fma(c, fma((((a * (a * (a * a))) * (c * 6.328125)) / (((b * b) * (b * t_0)) * (a * b))), -0.16666666666666666, (((a * a) * -0.5625) / ((b * b) * t_0))), ((a * -0.375) / t_0)) * (c * c)));
}
function code(a, b, c)
	t_0 = Float64(b * Float64(b * b))
	return fma(Float64(-0.5 / b), c, Float64(fma(c, fma(Float64(Float64(Float64(a * Float64(a * Float64(a * a))) * Float64(c * 6.328125)) / Float64(Float64(Float64(b * b) * Float64(b * t_0)) * Float64(a * b))), -0.16666666666666666, Float64(Float64(Float64(a * a) * -0.5625) / Float64(Float64(b * b) * t_0))), Float64(Float64(a * -0.375) / t_0)) * Float64(c * c)))
end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(-0.5 / b), $MachinePrecision] * c + N[(N[(c * N[(N[(N[(N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * 6.328125), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(b * b), $MachinePrecision] * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision] * N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666 + N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a * -0.375), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot b\right)\\
\mathsf{fma}\left(\frac{-0.5}{b}, c, \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot 6.328125\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot t\_0\right)\right) \cdot \left(a \cdot b\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot t\_0}\right), \frac{a \cdot -0.375}{t\_0}\right) \cdot \left(c \cdot c\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 18.1%

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

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}} + c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2}}{{b}^{5}} + \frac{-1}{6} \cdot \frac{c \cdot \left(\frac{81}{64} \cdot \frac{{a}^{4}}{{b}^{6}} + \frac{81}{16} \cdot \frac{{a}^{4}}{{b}^{6}}\right)}{a \cdot b}\right)\right) - \frac{1}{2} \cdot \frac{1}{b}\right)} \]
  4. Applied rewrites96.9%

    \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(-0.16666666666666666, \frac{\frac{{a}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot c\right)}{a \cdot b}, \frac{\left(a \cdot a\right) \cdot -0.5625}{{b}^{5}}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right)} \]
  5. Applied rewrites97.0%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-0.5}{b}, c, \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(6.328125 \cdot c\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)\right) \cdot \left(b \cdot a\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right) \cdot \left(c \cdot c\right)\right)} \]
  6. Final simplification97.0%

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

Alternative 3: 97.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := b \cdot \left(b \cdot b\right)\\ c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot 6.328125\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot t\_0\right)\right) \cdot \left(a \cdot b\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot t\_0}\right), \frac{a \cdot -0.375}{t\_0}\right), \frac{-0.5}{b}\right) \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (* b (* b b))))
   (*
    c
    (fma
     c
     (fma
      c
      (fma
       (/
        (* (* a (* a (* a a))) (* c 6.328125))
        (* (* (* b b) (* b t_0)) (* a b)))
       -0.16666666666666666
       (/ (* (* a a) -0.5625) (* (* b b) t_0)))
      (/ (* a -0.375) t_0))
     (/ -0.5 b)))))
double code(double a, double b, double c) {
	double t_0 = b * (b * b);
	return c * fma(c, fma(c, fma((((a * (a * (a * a))) * (c * 6.328125)) / (((b * b) * (b * t_0)) * (a * b))), -0.16666666666666666, (((a * a) * -0.5625) / ((b * b) * t_0))), ((a * -0.375) / t_0)), (-0.5 / b));
}
function code(a, b, c)
	t_0 = Float64(b * Float64(b * b))
	return Float64(c * fma(c, fma(c, fma(Float64(Float64(Float64(a * Float64(a * Float64(a * a))) * Float64(c * 6.328125)) / Float64(Float64(Float64(b * b) * Float64(b * t_0)) * Float64(a * b))), -0.16666666666666666, Float64(Float64(Float64(a * a) * -0.5625) / Float64(Float64(b * b) * t_0))), Float64(Float64(a * -0.375) / t_0)), Float64(-0.5 / b)))
end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(c * N[(c * N[(c * N[(N[(N[(N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * 6.328125), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(b * b), $MachinePrecision] * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision] * N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666 + N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a * -0.375), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] + N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot b\right)\\
c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot 6.328125\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot t\_0\right)\right) \cdot \left(a \cdot b\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot t\_0}\right), \frac{a \cdot -0.375}{t\_0}\right), \frac{-0.5}{b}\right)
\end{array}
\end{array}
Derivation
  1. Initial program 18.1%

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

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}} + c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2}}{{b}^{5}} + \frac{-1}{6} \cdot \frac{c \cdot \left(\frac{81}{64} \cdot \frac{{a}^{4}}{{b}^{6}} + \frac{81}{16} \cdot \frac{{a}^{4}}{{b}^{6}}\right)}{a \cdot b}\right)\right) - \frac{1}{2} \cdot \frac{1}{b}\right)} \]
  4. Applied rewrites96.9%

    \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(-0.16666666666666666, \frac{\frac{{a}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot c\right)}{a \cdot b}, \frac{\left(a \cdot a\right) \cdot -0.5625}{{b}^{5}}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right)} \]
  5. Applied rewrites96.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(\frac{\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(6.328125 \cdot c\right)}{\left(\left(b \cdot b\right) \cdot \left(b \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)\right) \cdot \left(b \cdot a\right)}, -0.16666666666666666, \frac{\left(a \cdot a\right) \cdot -0.5625}{\left(b \cdot b\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right) \cdot c} \]
  6. Final simplification96.9%

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

Alternative 4: 96.7% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\frac{\mathsf{fma}\left(-0.5625, \frac{c \cdot \left(a \cdot a\right)}{b \cdot b}, a \cdot -0.375\right)}{b \cdot \left(b \cdot b\right)}, c \cdot c, \frac{c}{b \cdot -2}\right) \end{array} \]
(FPCore (a b c)
 :precision binary64
 (fma
  (/ (fma -0.5625 (/ (* c (* a a)) (* b b)) (* a -0.375)) (* b (* b b)))
  (* c c)
  (/ c (* b -2.0))))
double code(double a, double b, double c) {
	return fma((fma(-0.5625, ((c * (a * a)) / (b * b)), (a * -0.375)) / (b * (b * b))), (c * c), (c / (b * -2.0)));
}
function code(a, b, c)
	return fma(Float64(fma(-0.5625, Float64(Float64(c * Float64(a * a)) / Float64(b * b)), Float64(a * -0.375)) / Float64(b * Float64(b * b))), Float64(c * c), Float64(c / Float64(b * -2.0)))
end
code[a_, b_, c_] := N[(N[(N[(-0.5625 * N[(N[(c * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(a * -0.375), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision] + N[(c / N[(b * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\frac{\mathsf{fma}\left(-0.5625, \frac{c \cdot \left(a \cdot a\right)}{b \cdot b}, a \cdot -0.375\right)}{b \cdot \left(b \cdot b\right)}, c \cdot c, \frac{c}{b \cdot -2}\right)
\end{array}
Derivation
  1. Initial program 18.1%

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

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(\frac{-3}{8} \cdot \frac{a}{{b}^{3}} + c \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2}}{{b}^{5}} + \frac{-1}{6} \cdot \frac{c \cdot \left(\frac{81}{64} \cdot \frac{{a}^{4}}{{b}^{6}} + \frac{81}{16} \cdot \frac{{a}^{4}}{{b}^{6}}\right)}{a \cdot b}\right)\right) - \frac{1}{2} \cdot \frac{1}{b}\right)} \]
  4. Applied rewrites96.9%

    \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(c, \mathsf{fma}\left(c, \mathsf{fma}\left(-0.16666666666666666, \frac{\frac{{a}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot c\right)}{a \cdot b}, \frac{\left(a \cdot a\right) \cdot -0.5625}{{b}^{5}}\right), \frac{a \cdot -0.375}{b \cdot \left(b \cdot b\right)}\right), \frac{-0.5}{b}\right)} \]
  5. Applied rewrites97.3%

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

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

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

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

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

      \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{-9}{16}, \frac{\color{blue}{{a}^{2} \cdot c}}{{b}^{2}}, \frac{-3}{8} \cdot a\right)}{{b}^{3}}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
    5. unpow2N/A

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

      \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{-9}{16}, \frac{\color{blue}{\left(a \cdot a\right)} \cdot c}{{b}^{2}}, \frac{-3}{8} \cdot a\right)}{{b}^{3}}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
    7. unpow2N/A

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

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

      \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{-9}{16}, \frac{\left(a \cdot a\right) \cdot c}{b \cdot b}, \color{blue}{\frac{-3}{8} \cdot a}\right)}{{b}^{3}}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
    10. cube-multN/A

      \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{-9}{16}, \frac{\left(a \cdot a\right) \cdot c}{b \cdot b}, \frac{-3}{8} \cdot a\right)}{\color{blue}{b \cdot \left(b \cdot b\right)}}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
    11. unpow2N/A

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

      \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{-9}{16}, \frac{\left(a \cdot a\right) \cdot c}{b \cdot b}, \frac{-3}{8} \cdot a\right)}{\color{blue}{b \cdot {b}^{2}}}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
    13. unpow2N/A

      \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{-9}{16}, \frac{\left(a \cdot a\right) \cdot c}{b \cdot b}, \frac{-3}{8} \cdot a\right)}{b \cdot \color{blue}{\left(b \cdot b\right)}}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
    14. lower-*.f6496.2

      \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(-0.5625, \frac{\left(a \cdot a\right) \cdot c}{b \cdot b}, -0.375 \cdot a\right)}{b \cdot \color{blue}{\left(b \cdot b\right)}}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
  8. Applied rewrites96.2%

    \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\mathsf{fma}\left(-0.5625, \frac{\left(a \cdot a\right) \cdot c}{b \cdot b}, -0.375 \cdot a\right)}{b \cdot \left(b \cdot b\right)}}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
  9. Final simplification96.2%

    \[\leadsto \mathsf{fma}\left(\frac{\mathsf{fma}\left(-0.5625, \frac{c \cdot \left(a \cdot a\right)}{b \cdot b}, a \cdot -0.375\right)}{b \cdot \left(b \cdot b\right)}, c \cdot c, \frac{c}{b \cdot -2}\right) \]
  10. Add Preprocessing

Alternative 5: 95.2% accurate, 1.0× speedup?

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

\\
\frac{\mathsf{fma}\left(a, \frac{-0.375 \cdot \left(c \cdot c\right)}{b \cdot b}, c \cdot -0.5\right)}{b}
\end{array}
Derivation
  1. Initial program 18.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  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 rewrites94.5%

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

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

Alternative 6: 94.8% 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 18.1%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    \[\leadsto \color{blue}{c \cdot \mathsf{fma}\left(a, \frac{c}{b \cdot \left(b \cdot b\right)} \cdot -0.375, \frac{-0.5}{b}\right)} \]
  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-*.f6494.2

      \[\leadsto c \cdot \frac{\mathsf{fma}\left(-0.375, \frac{a \cdot c}{\color{blue}{b \cdot b}}, -0.5\right)}{b} \]
  8. Applied rewrites94.2%

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

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

Alternative 7: 90.3% 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 18.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  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-/.f6490.0

      \[\leadsto -0.5 \cdot \color{blue}{\frac{c}{b}} \]
  5. Applied rewrites90.0%

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

Alternative 8: 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 18.1%

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - b}{\color{blue}{3 \cdot a}} \]
    11. div-subN/A

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

      \[\leadsto \color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} - \frac{b}{3 \cdot a}} \]
  4. Applied rewrites17.8%

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

    \[\leadsto \color{blue}{\frac{1}{\frac{\left(a \cdot a\right) \cdot 9}{\mathsf{fma}\left(\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}, a \cdot 3, \left(a \cdot -3\right) \cdot b\right)}}} \]
  6. Taylor expanded in a around 0

    \[\leadsto \color{blue}{\frac{1}{9} \cdot \frac{-3 \cdot b + 3 \cdot b}{a}} \]
  7. Step-by-step derivation
    1. associate-*r/N/A

      \[\leadsto \color{blue}{\frac{\frac{1}{9} \cdot \left(-3 \cdot b + 3 \cdot b\right)}{a}} \]
    2. distribute-rgt-outN/A

      \[\leadsto \frac{\frac{1}{9} \cdot \color{blue}{\left(b \cdot \left(-3 + 3\right)\right)}}{a} \]
    3. metadata-evalN/A

      \[\leadsto \frac{\frac{1}{9} \cdot \left(b \cdot \color{blue}{0}\right)}{a} \]
    4. mul0-rgtN/A

      \[\leadsto \frac{\frac{1}{9} \cdot \color{blue}{0}}{a} \]
    5. metadata-evalN/A

      \[\leadsto \frac{\color{blue}{0}}{a} \]
    6. lower-/.f643.3

      \[\leadsto \color{blue}{\frac{0}{a}} \]
  8. Applied rewrites3.3%

    \[\leadsto \color{blue}{\frac{0}{a}} \]
  9. Step-by-step derivation
    1. div03.3

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

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

Reproduce

?
herbie shell --seed 2024214 
(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)))