Cubic critical, wide range

Percentage Accurate: 18.0% → 97.7%
Time: 16.5s
Alternatives: 9
Speedup: 23.2×

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 9 alternatives:

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

Initial Program: 18.0% 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: 97.7% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \frac{0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \left(c \cdot 0.5 + \left(0.5625 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + 1.0546875 \cdot \frac{{a}^{3} \cdot {c}^{4}}{{b}^{6}}\right)\right)}{-b} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/
  (+
   (* 0.375 (/ (* a (pow c 2.0)) (pow b 2.0)))
   (+
    (* c 0.5)
    (+
     (* 0.5625 (/ (* (pow a 2.0) (pow c 3.0)) (pow b 4.0)))
     (* 1.0546875 (/ (* (pow a 3.0) (pow c 4.0)) (pow b 6.0))))))
  (- b)))
double code(double a, double b, double c) {
	return ((0.375 * ((a * pow(c, 2.0)) / pow(b, 2.0))) + ((c * 0.5) + ((0.5625 * ((pow(a, 2.0) * pow(c, 3.0)) / pow(b, 4.0))) + (1.0546875 * ((pow(a, 3.0) * pow(c, 4.0)) / pow(b, 6.0)))))) / -b;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = ((0.375d0 * ((a * (c ** 2.0d0)) / (b ** 2.0d0))) + ((c * 0.5d0) + ((0.5625d0 * (((a ** 2.0d0) * (c ** 3.0d0)) / (b ** 4.0d0))) + (1.0546875d0 * (((a ** 3.0d0) * (c ** 4.0d0)) / (b ** 6.0d0)))))) / -b
end function
public static double code(double a, double b, double c) {
	return ((0.375 * ((a * Math.pow(c, 2.0)) / Math.pow(b, 2.0))) + ((c * 0.5) + ((0.5625 * ((Math.pow(a, 2.0) * Math.pow(c, 3.0)) / Math.pow(b, 4.0))) + (1.0546875 * ((Math.pow(a, 3.0) * Math.pow(c, 4.0)) / Math.pow(b, 6.0)))))) / -b;
}
def code(a, b, c):
	return ((0.375 * ((a * math.pow(c, 2.0)) / math.pow(b, 2.0))) + ((c * 0.5) + ((0.5625 * ((math.pow(a, 2.0) * math.pow(c, 3.0)) / math.pow(b, 4.0))) + (1.0546875 * ((math.pow(a, 3.0) * math.pow(c, 4.0)) / math.pow(b, 6.0)))))) / -b
function code(a, b, c)
	return Float64(Float64(Float64(0.375 * Float64(Float64(a * (c ^ 2.0)) / (b ^ 2.0))) + Float64(Float64(c * 0.5) + Float64(Float64(0.5625 * Float64(Float64((a ^ 2.0) * (c ^ 3.0)) / (b ^ 4.0))) + Float64(1.0546875 * Float64(Float64((a ^ 3.0) * (c ^ 4.0)) / (b ^ 6.0)))))) / Float64(-b))
end
function tmp = code(a, b, c)
	tmp = ((0.375 * ((a * (c ^ 2.0)) / (b ^ 2.0))) + ((c * 0.5) + ((0.5625 * (((a ^ 2.0) * (c ^ 3.0)) / (b ^ 4.0))) + (1.0546875 * (((a ^ 3.0) * (c ^ 4.0)) / (b ^ 6.0)))))) / -b;
end
code[a_, b_, c_] := N[(N[(N[(0.375 * N[(N[(a * N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(c * 0.5), $MachinePrecision] + N[(N[(0.5625 * N[(N[(N[Power[a, 2.0], $MachinePrecision] * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.0546875 * N[(N[(N[Power[a, 3.0], $MachinePrecision] * N[Power[c, 4.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / (-b)), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \left(c \cdot 0.5 + \left(0.5625 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + 1.0546875 \cdot \frac{{a}^{3} \cdot {c}^{4}}{{b}^{6}}\right)\right)}{-b}
\end{array}
Derivation
  1. Initial program 22.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0 96.7%

    \[\leadsto \frac{\color{blue}{a \cdot \left(-1.5 \cdot \frac{c}{b} + a \cdot \left(-1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)\right)}}{3 \cdot a} \]
  4. Step-by-step derivation
    1. +-commutative96.7%

      \[\leadsto \frac{a \cdot \color{blue}{\left(a \cdot \left(-1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right) + -1.5 \cdot \frac{c}{b}\right)}}{3 \cdot a} \]
    2. fma-define96.7%

      \[\leadsto \frac{a \cdot \color{blue}{\mathsf{fma}\left(a, -1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right), -1.5 \cdot \frac{c}{b}\right)}}{3 \cdot a} \]
  5. Simplified96.7%

    \[\leadsto \frac{\color{blue}{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(-0.5, \frac{\frac{{c}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot a\right)}{b}, \frac{-1.6875 \cdot {c}^{3}}{{b}^{5}}\right), \frac{-1.125 \cdot {c}^{2}}{{b}^{3}}\right), \frac{-1.5 \cdot c}{b}\right)}}{3 \cdot a} \]
  6. Taylor expanded in b around -inf 97.3%

    \[\leadsto \color{blue}{-1 \cdot \frac{0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \left(0.5 \cdot c + \left(0.5625 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + 1.0546875 \cdot \frac{{a}^{3} \cdot {c}^{4}}{{b}^{6}}\right)\right)}{b}} \]
  7. Final simplification97.3%

    \[\leadsto \frac{0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \left(c \cdot 0.5 + \left(0.5625 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + 1.0546875 \cdot \frac{{a}^{3} \cdot {c}^{4}}{{b}^{6}}\right)\right)}{-b} \]
  8. Add Preprocessing

Alternative 2: 97.7% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \frac{\frac{{a}^{3} \cdot {c}^{4}}{{b}^{6}} \cdot -1.0546875 + \left(\frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} \cdot -0.5625 + \left(c \cdot -0.5 + \frac{a \cdot {c}^{2}}{{b}^{2}} \cdot -0.375\right)\right)}{b} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/
  (+
   (* (/ (* (pow a 3.0) (pow c 4.0)) (pow b 6.0)) -1.0546875)
   (+
    (* (/ (* (pow a 2.0) (pow c 3.0)) (pow b 4.0)) -0.5625)
    (+ (* c -0.5) (* (/ (* a (pow c 2.0)) (pow b 2.0)) -0.375))))
  b))
double code(double a, double b, double c) {
	return ((((pow(a, 3.0) * pow(c, 4.0)) / pow(b, 6.0)) * -1.0546875) + ((((pow(a, 2.0) * pow(c, 3.0)) / pow(b, 4.0)) * -0.5625) + ((c * -0.5) + (((a * pow(c, 2.0)) / pow(b, 2.0)) * -0.375)))) / b;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (((((a ** 3.0d0) * (c ** 4.0d0)) / (b ** 6.0d0)) * (-1.0546875d0)) + (((((a ** 2.0d0) * (c ** 3.0d0)) / (b ** 4.0d0)) * (-0.5625d0)) + ((c * (-0.5d0)) + (((a * (c ** 2.0d0)) / (b ** 2.0d0)) * (-0.375d0))))) / b
end function
public static double code(double a, double b, double c) {
	return ((((Math.pow(a, 3.0) * Math.pow(c, 4.0)) / Math.pow(b, 6.0)) * -1.0546875) + ((((Math.pow(a, 2.0) * Math.pow(c, 3.0)) / Math.pow(b, 4.0)) * -0.5625) + ((c * -0.5) + (((a * Math.pow(c, 2.0)) / Math.pow(b, 2.0)) * -0.375)))) / b;
}
def code(a, b, c):
	return ((((math.pow(a, 3.0) * math.pow(c, 4.0)) / math.pow(b, 6.0)) * -1.0546875) + ((((math.pow(a, 2.0) * math.pow(c, 3.0)) / math.pow(b, 4.0)) * -0.5625) + ((c * -0.5) + (((a * math.pow(c, 2.0)) / math.pow(b, 2.0)) * -0.375)))) / b
function code(a, b, c)
	return Float64(Float64(Float64(Float64(Float64((a ^ 3.0) * (c ^ 4.0)) / (b ^ 6.0)) * -1.0546875) + Float64(Float64(Float64(Float64((a ^ 2.0) * (c ^ 3.0)) / (b ^ 4.0)) * -0.5625) + Float64(Float64(c * -0.5) + Float64(Float64(Float64(a * (c ^ 2.0)) / (b ^ 2.0)) * -0.375)))) / b)
end
function tmp = code(a, b, c)
	tmp = (((((a ^ 3.0) * (c ^ 4.0)) / (b ^ 6.0)) * -1.0546875) + (((((a ^ 2.0) * (c ^ 3.0)) / (b ^ 4.0)) * -0.5625) + ((c * -0.5) + (((a * (c ^ 2.0)) / (b ^ 2.0)) * -0.375)))) / b;
end
code[a_, b_, c_] := N[(N[(N[(N[(N[(N[Power[a, 3.0], $MachinePrecision] * N[Power[c, 4.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] * -1.0546875), $MachinePrecision] + N[(N[(N[(N[(N[Power[a, 2.0], $MachinePrecision] * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 4.0], $MachinePrecision]), $MachinePrecision] * -0.5625), $MachinePrecision] + N[(N[(c * -0.5), $MachinePrecision] + N[(N[(N[(a * N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision] * -0.375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{{a}^{3} \cdot {c}^{4}}{{b}^{6}} \cdot -1.0546875 + \left(\frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} \cdot -0.5625 + \left(c \cdot -0.5 + \frac{a \cdot {c}^{2}}{{b}^{2}} \cdot -0.375\right)\right)}{b}
\end{array}
Derivation
  1. Initial program 22.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0 96.7%

    \[\leadsto \frac{\color{blue}{a \cdot \left(-1.5 \cdot \frac{c}{b} + a \cdot \left(-1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)\right)}}{3 \cdot a} \]
  4. Step-by-step derivation
    1. +-commutative96.7%

      \[\leadsto \frac{a \cdot \color{blue}{\left(a \cdot \left(-1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right) + -1.5 \cdot \frac{c}{b}\right)}}{3 \cdot a} \]
    2. fma-define96.7%

      \[\leadsto \frac{a \cdot \color{blue}{\mathsf{fma}\left(a, -1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right), -1.5 \cdot \frac{c}{b}\right)}}{3 \cdot a} \]
  5. Simplified96.7%

    \[\leadsto \frac{\color{blue}{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(-0.5, \frac{\frac{{c}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot a\right)}{b}, \frac{-1.6875 \cdot {c}^{3}}{{b}^{5}}\right), \frac{-1.125 \cdot {c}^{2}}{{b}^{3}}\right), \frac{-1.5 \cdot c}{b}\right)}}{3 \cdot a} \]
  6. Taylor expanded in b around inf 97.3%

    \[\leadsto \color{blue}{\frac{-1.0546875 \cdot \frac{{a}^{3} \cdot {c}^{4}}{{b}^{6}} + \left(-0.5625 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(-0.5 \cdot c + -0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}\right)\right)}{b}} \]
  7. Final simplification97.3%

    \[\leadsto \frac{\frac{{a}^{3} \cdot {c}^{4}}{{b}^{6}} \cdot -1.0546875 + \left(\frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} \cdot -0.5625 + \left(c \cdot -0.5 + \frac{a \cdot {c}^{2}}{{b}^{2}} \cdot -0.375\right)\right)}{b} \]
  8. Add Preprocessing

Alternative 3: 97.7% accurate, 0.2× speedup?

\[\begin{array}{l} \\ -0.5 \cdot \frac{c}{b} + a \cdot \left(-0.375 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-0.5625 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{{c}^{4} \cdot \left(a \cdot -1.0546875\right)}{{b}^{7}}\right)\right) \end{array} \]
(FPCore (a b c)
 :precision binary64
 (+
  (* -0.5 (/ c b))
  (*
   a
   (+
    (* -0.375 (/ (pow c 2.0) (pow b 3.0)))
    (*
     a
     (+
      (* -0.5625 (/ (pow c 3.0) (pow b 5.0)))
      (/ (* (pow c 4.0) (* a -1.0546875)) (pow b 7.0))))))))
double code(double a, double b, double c) {
	return (-0.5 * (c / b)) + (a * ((-0.375 * (pow(c, 2.0) / pow(b, 3.0))) + (a * ((-0.5625 * (pow(c, 3.0) / pow(b, 5.0))) + ((pow(c, 4.0) * (a * -1.0546875)) / pow(b, 7.0))))));
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = ((-0.5d0) * (c / b)) + (a * (((-0.375d0) * ((c ** 2.0d0) / (b ** 3.0d0))) + (a * (((-0.5625d0) * ((c ** 3.0d0) / (b ** 5.0d0))) + (((c ** 4.0d0) * (a * (-1.0546875d0))) / (b ** 7.0d0))))))
end function
public static double code(double a, double b, double c) {
	return (-0.5 * (c / b)) + (a * ((-0.375 * (Math.pow(c, 2.0) / Math.pow(b, 3.0))) + (a * ((-0.5625 * (Math.pow(c, 3.0) / Math.pow(b, 5.0))) + ((Math.pow(c, 4.0) * (a * -1.0546875)) / Math.pow(b, 7.0))))));
}
def code(a, b, c):
	return (-0.5 * (c / b)) + (a * ((-0.375 * (math.pow(c, 2.0) / math.pow(b, 3.0))) + (a * ((-0.5625 * (math.pow(c, 3.0) / math.pow(b, 5.0))) + ((math.pow(c, 4.0) * (a * -1.0546875)) / math.pow(b, 7.0))))))
function code(a, b, c)
	return Float64(Float64(-0.5 * Float64(c / b)) + Float64(a * Float64(Float64(-0.375 * Float64((c ^ 2.0) / (b ^ 3.0))) + Float64(a * Float64(Float64(-0.5625 * Float64((c ^ 3.0) / (b ^ 5.0))) + Float64(Float64((c ^ 4.0) * Float64(a * -1.0546875)) / (b ^ 7.0)))))))
end
function tmp = code(a, b, c)
	tmp = (-0.5 * (c / b)) + (a * ((-0.375 * ((c ^ 2.0) / (b ^ 3.0))) + (a * ((-0.5625 * ((c ^ 3.0) / (b ^ 5.0))) + (((c ^ 4.0) * (a * -1.0546875)) / (b ^ 7.0))))));
end
code[a_, b_, c_] := N[(N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision] + N[(a * N[(N[(-0.375 * N[(N[Power[c, 2.0], $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(a * N[(N[(-0.5625 * N[(N[Power[c, 3.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[Power[c, 4.0], $MachinePrecision] * N[(a * -1.0546875), $MachinePrecision]), $MachinePrecision] / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
-0.5 \cdot \frac{c}{b} + a \cdot \left(-0.375 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-0.5625 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{{c}^{4} \cdot \left(a \cdot -1.0546875\right)}{{b}^{7}}\right)\right)
\end{array}
Derivation
  1. Initial program 22.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0 97.2%

    \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b} + a \cdot \left(-0.375 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-0.5625 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.16666666666666666 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)} \]
  4. Taylor expanded in c around 0 97.2%

    \[\leadsto -0.5 \cdot \frac{c}{b} + a \cdot \left(-0.375 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-0.5625 \cdot \frac{{c}^{3}}{{b}^{5}} + \color{blue}{-1.0546875 \cdot \frac{a \cdot {c}^{4}}{{b}^{7}}}\right)\right) \]
  5. Step-by-step derivation
    1. associate-*r/97.2%

      \[\leadsto -0.5 \cdot \frac{c}{b} + a \cdot \left(-0.375 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-0.5625 \cdot \frac{{c}^{3}}{{b}^{5}} + \color{blue}{\frac{-1.0546875 \cdot \left(a \cdot {c}^{4}\right)}{{b}^{7}}}\right)\right) \]
    2. associate-*r*97.2%

      \[\leadsto -0.5 \cdot \frac{c}{b} + a \cdot \left(-0.375 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-0.5625 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{\color{blue}{\left(-1.0546875 \cdot a\right) \cdot {c}^{4}}}{{b}^{7}}\right)\right) \]
  6. Simplified97.2%

    \[\leadsto -0.5 \cdot \frac{c}{b} + a \cdot \left(-0.375 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-0.5625 \cdot \frac{{c}^{3}}{{b}^{5}} + \color{blue}{\frac{\left(-1.0546875 \cdot a\right) \cdot {c}^{4}}{{b}^{7}}}\right)\right) \]
  7. Final simplification97.2%

    \[\leadsto -0.5 \cdot \frac{c}{b} + a \cdot \left(-0.375 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-0.5625 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{{c}^{4} \cdot \left(a \cdot -1.0546875\right)}{{b}^{7}}\right)\right) \]
  8. Add Preprocessing

Alternative 4: 97.4% accurate, 0.2× speedup?

\[\begin{array}{l} \\ c \cdot \left(c \cdot \left(-0.375 \cdot \frac{a}{{b}^{3}} + c \cdot \left(-1.0546875 \cdot \frac{c \cdot {a}^{3}}{{b}^{7}} + -0.5625 \cdot \frac{{a}^{2}}{{b}^{5}}\right)\right) + 0.5 \cdot \frac{-1}{b}\right) \end{array} \]
(FPCore (a b c)
 :precision binary64
 (*
  c
  (+
   (*
    c
    (+
     (* -0.375 (/ a (pow b 3.0)))
     (*
      c
      (+
       (* -1.0546875 (/ (* c (pow a 3.0)) (pow b 7.0)))
       (* -0.5625 (/ (pow a 2.0) (pow b 5.0)))))))
   (* 0.5 (/ -1.0 b)))))
double code(double a, double b, double c) {
	return c * ((c * ((-0.375 * (a / pow(b, 3.0))) + (c * ((-1.0546875 * ((c * pow(a, 3.0)) / pow(b, 7.0))) + (-0.5625 * (pow(a, 2.0) / pow(b, 5.0))))))) + (0.5 * (-1.0 / b)));
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = c * ((c * (((-0.375d0) * (a / (b ** 3.0d0))) + (c * (((-1.0546875d0) * ((c * (a ** 3.0d0)) / (b ** 7.0d0))) + ((-0.5625d0) * ((a ** 2.0d0) / (b ** 5.0d0))))))) + (0.5d0 * ((-1.0d0) / b)))
end function
public static double code(double a, double b, double c) {
	return c * ((c * ((-0.375 * (a / Math.pow(b, 3.0))) + (c * ((-1.0546875 * ((c * Math.pow(a, 3.0)) / Math.pow(b, 7.0))) + (-0.5625 * (Math.pow(a, 2.0) / Math.pow(b, 5.0))))))) + (0.5 * (-1.0 / b)));
}
def code(a, b, c):
	return c * ((c * ((-0.375 * (a / math.pow(b, 3.0))) + (c * ((-1.0546875 * ((c * math.pow(a, 3.0)) / math.pow(b, 7.0))) + (-0.5625 * (math.pow(a, 2.0) / math.pow(b, 5.0))))))) + (0.5 * (-1.0 / b)))
function code(a, b, c)
	return Float64(c * Float64(Float64(c * Float64(Float64(-0.375 * Float64(a / (b ^ 3.0))) + Float64(c * Float64(Float64(-1.0546875 * Float64(Float64(c * (a ^ 3.0)) / (b ^ 7.0))) + Float64(-0.5625 * Float64((a ^ 2.0) / (b ^ 5.0))))))) + Float64(0.5 * Float64(-1.0 / b))))
end
function tmp = code(a, b, c)
	tmp = c * ((c * ((-0.375 * (a / (b ^ 3.0))) + (c * ((-1.0546875 * ((c * (a ^ 3.0)) / (b ^ 7.0))) + (-0.5625 * ((a ^ 2.0) / (b ^ 5.0))))))) + (0.5 * (-1.0 / b)));
end
code[a_, b_, c_] := N[(c * N[(N[(c * N[(N[(-0.375 * N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c * N[(N[(-1.0546875 * N[(N[(c * N[Power[a, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5625 * N[(N[Power[a, 2.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(-1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
c \cdot \left(c \cdot \left(-0.375 \cdot \frac{a}{{b}^{3}} + c \cdot \left(-1.0546875 \cdot \frac{c \cdot {a}^{3}}{{b}^{7}} + -0.5625 \cdot \frac{{a}^{2}}{{b}^{5}}\right)\right) + 0.5 \cdot \frac{-1}{b}\right)
\end{array}
Derivation
  1. Initial program 22.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0 96.7%

    \[\leadsto \frac{\color{blue}{a \cdot \left(-1.5 \cdot \frac{c}{b} + a \cdot \left(-1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)\right)}}{3 \cdot a} \]
  4. Step-by-step derivation
    1. +-commutative96.7%

      \[\leadsto \frac{a \cdot \color{blue}{\left(a \cdot \left(-1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right) + -1.5 \cdot \frac{c}{b}\right)}}{3 \cdot a} \]
    2. fma-define96.7%

      \[\leadsto \frac{a \cdot \color{blue}{\mathsf{fma}\left(a, -1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right), -1.5 \cdot \frac{c}{b}\right)}}{3 \cdot a} \]
  5. Simplified96.7%

    \[\leadsto \frac{\color{blue}{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(-0.5, \frac{\frac{{c}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot a\right)}{b}, \frac{-1.6875 \cdot {c}^{3}}{{b}^{5}}\right), \frac{-1.125 \cdot {c}^{2}}{{b}^{3}}\right), \frac{-1.5 \cdot c}{b}\right)}}{3 \cdot a} \]
  6. Taylor expanded in c around 0 97.0%

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(-0.375 \cdot \frac{a}{{b}^{3}} + c \cdot \left(-1.0546875 \cdot \frac{{a}^{3} \cdot c}{{b}^{7}} + -0.5625 \cdot \frac{{a}^{2}}{{b}^{5}}\right)\right) - 0.5 \cdot \frac{1}{b}\right)} \]
  7. Final simplification97.0%

    \[\leadsto c \cdot \left(c \cdot \left(-0.375 \cdot \frac{a}{{b}^{3}} + c \cdot \left(-1.0546875 \cdot \frac{c \cdot {a}^{3}}{{b}^{7}} + -0.5625 \cdot \frac{{a}^{2}}{{b}^{5}}\right)\right) + 0.5 \cdot \frac{-1}{b}\right) \]
  8. Add Preprocessing

Alternative 5: 96.6% accurate, 0.4× speedup?

\[\begin{array}{l} \\ c \cdot \left(\frac{\mathsf{fma}\left(a \cdot c, -0.375, -0.5625 \cdot {\left(c \cdot \frac{a}{b}\right)}^{2}\right)}{{b}^{3}} + 0.5 \cdot \frac{-1}{b}\right) \end{array} \]
(FPCore (a b c)
 :precision binary64
 (*
  c
  (+
   (/ (fma (* a c) -0.375 (* -0.5625 (pow (* c (/ a b)) 2.0))) (pow b 3.0))
   (* 0.5 (/ -1.0 b)))))
double code(double a, double b, double c) {
	return c * ((fma((a * c), -0.375, (-0.5625 * pow((c * (a / b)), 2.0))) / pow(b, 3.0)) + (0.5 * (-1.0 / b)));
}
function code(a, b, c)
	return Float64(c * Float64(Float64(fma(Float64(a * c), -0.375, Float64(-0.5625 * (Float64(c * Float64(a / b)) ^ 2.0))) / (b ^ 3.0)) + Float64(0.5 * Float64(-1.0 / b))))
end
code[a_, b_, c_] := N[(c * N[(N[(N[(N[(a * c), $MachinePrecision] * -0.375 + N[(-0.5625 * N[Power[N[(c * N[(a / b), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(-1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
c \cdot \left(\frac{\mathsf{fma}\left(a \cdot c, -0.375, -0.5625 \cdot {\left(c \cdot \frac{a}{b}\right)}^{2}\right)}{{b}^{3}} + 0.5 \cdot \frac{-1}{b}\right)
\end{array}
Derivation
  1. Initial program 22.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0 96.7%

    \[\leadsto \frac{\color{blue}{a \cdot \left(-1.5 \cdot \frac{c}{b} + a \cdot \left(-1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)\right)}}{3 \cdot a} \]
  4. Step-by-step derivation
    1. +-commutative96.7%

      \[\leadsto \frac{a \cdot \color{blue}{\left(a \cdot \left(-1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right) + -1.5 \cdot \frac{c}{b}\right)}}{3 \cdot a} \]
    2. fma-define96.7%

      \[\leadsto \frac{a \cdot \color{blue}{\mathsf{fma}\left(a, -1.125 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-1.6875 \cdot \frac{{c}^{3}}{{b}^{5}} + -0.5 \cdot \frac{a \cdot \left(1.265625 \cdot \frac{{c}^{4}}{{b}^{6}} + 5.0625 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right), -1.5 \cdot \frac{c}{b}\right)}}{3 \cdot a} \]
  5. Simplified96.7%

    \[\leadsto \frac{\color{blue}{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(-0.5, \frac{\frac{{c}^{4}}{{b}^{6}} \cdot \left(6.328125 \cdot a\right)}{b}, \frac{-1.6875 \cdot {c}^{3}}{{b}^{5}}\right), \frac{-1.125 \cdot {c}^{2}}{{b}^{3}}\right), \frac{-1.5 \cdot c}{b}\right)}}{3 \cdot a} \]
  6. Taylor expanded in c around 0 97.0%

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(-0.375 \cdot \frac{a}{{b}^{3}} + c \cdot \left(-1.0546875 \cdot \frac{{a}^{3} \cdot c}{{b}^{7}} + -0.5625 \cdot \frac{{a}^{2}}{{b}^{5}}\right)\right) - 0.5 \cdot \frac{1}{b}\right)} \]
  7. Taylor expanded in b around inf 96.0%

    \[\leadsto c \cdot \left(\color{blue}{\frac{-0.5625 \cdot \frac{{a}^{2} \cdot {c}^{2}}{{b}^{2}} + -0.375 \cdot \left(a \cdot c\right)}{{b}^{3}}} - 0.5 \cdot \frac{1}{b}\right) \]
  8. Step-by-step derivation
    1. +-commutative96.0%

      \[\leadsto c \cdot \left(\frac{\color{blue}{-0.375 \cdot \left(a \cdot c\right) + -0.5625 \cdot \frac{{a}^{2} \cdot {c}^{2}}{{b}^{2}}}}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    2. *-commutative96.0%

      \[\leadsto c \cdot \left(\frac{\color{blue}{\left(a \cdot c\right) \cdot -0.375} + -0.5625 \cdot \frac{{a}^{2} \cdot {c}^{2}}{{b}^{2}}}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    3. fma-define96.0%

      \[\leadsto c \cdot \left(\frac{\color{blue}{\mathsf{fma}\left(a \cdot c, -0.375, -0.5625 \cdot \frac{{a}^{2} \cdot {c}^{2}}{{b}^{2}}\right)}}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    4. *-commutative96.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(\color{blue}{c \cdot a}, -0.375, -0.5625 \cdot \frac{{a}^{2} \cdot {c}^{2}}{{b}^{2}}\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    5. associate-/l*96.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot \color{blue}{\left({a}^{2} \cdot \frac{{c}^{2}}{{b}^{2}}\right)}\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    6. unpow296.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot \frac{{c}^{2}}{{b}^{2}}\right)\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    7. unpow296.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot \left(\left(a \cdot a\right) \cdot \frac{\color{blue}{c \cdot c}}{{b}^{2}}\right)\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    8. unpow296.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot \left(\left(a \cdot a\right) \cdot \frac{c \cdot c}{\color{blue}{b \cdot b}}\right)\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    9. times-frac96.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(\frac{c}{b} \cdot \frac{c}{b}\right)}\right)\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    10. swap-sqr96.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot \color{blue}{\left(\left(a \cdot \frac{c}{b}\right) \cdot \left(a \cdot \frac{c}{b}\right)\right)}\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    11. unpow296.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot \color{blue}{{\left(a \cdot \frac{c}{b}\right)}^{2}}\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    12. associate-*r/96.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot {\color{blue}{\left(\frac{a \cdot c}{b}\right)}}^{2}\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    13. *-commutative96.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot {\left(\frac{\color{blue}{c \cdot a}}{b}\right)}^{2}\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
    14. associate-/l*96.0%

      \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot {\color{blue}{\left(c \cdot \frac{a}{b}\right)}}^{2}\right)}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right) \]
  9. Simplified96.0%

    \[\leadsto c \cdot \left(\color{blue}{\frac{\mathsf{fma}\left(c \cdot a, -0.375, -0.5625 \cdot {\left(c \cdot \frac{a}{b}\right)}^{2}\right)}{{b}^{3}}} - 0.5 \cdot \frac{1}{b}\right) \]
  10. Final simplification96.0%

    \[\leadsto c \cdot \left(\frac{\mathsf{fma}\left(a \cdot c, -0.375, -0.5625 \cdot {\left(c \cdot \frac{a}{b}\right)}^{2}\right)}{{b}^{3}} + 0.5 \cdot \frac{-1}{b}\right) \]
  11. Add Preprocessing

Alternative 6: 95.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \frac{\mathsf{fma}\left(c, -0.5, a \cdot \left(-0.375 \cdot {\left(\frac{c}{b}\right)}^{2}\right)\right)}{b} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (fma c -0.5 (* a (* -0.375 (pow (/ c b) 2.0)))) b))
double code(double a, double b, double c) {
	return fma(c, -0.5, (a * (-0.375 * pow((c / b), 2.0)))) / b;
}
function code(a, b, c)
	return Float64(fma(c, -0.5, Float64(a * Float64(-0.375 * (Float64(c / b) ^ 2.0)))) / b)
end
code[a_, b_, c_] := N[(N[(c * -0.5 + N[(a * N[(-0.375 * N[Power[N[(c / b), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}

\\
\frac{\mathsf{fma}\left(c, -0.5, a \cdot \left(-0.375 \cdot {\left(\frac{c}{b}\right)}^{2}\right)\right)}{b}
\end{array}
Derivation
  1. Initial program 22.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in c around 0 93.7%

    \[\leadsto \frac{\color{blue}{c \cdot \left(-1.5 \cdot \frac{a}{b} + -1.125 \cdot \frac{{a}^{2} \cdot c}{{b}^{3}}\right)}}{3 \cdot a} \]
  4. Taylor expanded in a around inf 94.0%

    \[\leadsto \color{blue}{a \cdot \left(-0.5 \cdot \frac{c}{a \cdot b} + -0.375 \cdot \frac{{c}^{2}}{{b}^{3}}\right)} \]
  5. Taylor expanded in b around inf 94.5%

    \[\leadsto \color{blue}{\frac{-0.5 \cdot c + -0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
  6. Step-by-step derivation
    1. Simplified94.5%

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

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

    Alternative 7: 94.9% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - \frac{0.5}{b}\right) \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (* c (- (* -0.375 (/ (* a c) (pow b 3.0))) (/ 0.5 b))))
    double code(double a, double b, double c) {
    	return c * ((-0.375 * ((a * c) / pow(b, 3.0))) - (0.5 / b));
    }
    
    real(8) function code(a, b, c)
        real(8), intent (in) :: a
        real(8), intent (in) :: b
        real(8), intent (in) :: c
        code = c * (((-0.375d0) * ((a * c) / (b ** 3.0d0))) - (0.5d0 / b))
    end function
    
    public static double code(double a, double b, double c) {
    	return c * ((-0.375 * ((a * c) / Math.pow(b, 3.0))) - (0.5 / b));
    }
    
    def code(a, b, c):
    	return c * ((-0.375 * ((a * c) / math.pow(b, 3.0))) - (0.5 / b))
    
    function code(a, b, c)
    	return Float64(c * Float64(Float64(-0.375 * Float64(Float64(a * c) / (b ^ 3.0))) - Float64(0.5 / b)))
    end
    
    function tmp = code(a, b, c)
    	tmp = c * ((-0.375 * ((a * c) / (b ^ 3.0))) - (0.5 / b));
    end
    
    code[a_, b_, c_] := N[(c * N[(N[(-0.375 * N[(N[(a * c), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - \frac{0.5}{b}\right)
    \end{array}
    
    Derivation
    1. Initial program 22.1%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Taylor expanded in c around 0 93.7%

      \[\leadsto \frac{\color{blue}{c \cdot \left(-1.5 \cdot \frac{a}{b} + -1.125 \cdot \frac{{a}^{2} \cdot c}{{b}^{3}}\right)}}{3 \cdot a} \]
    4. Taylor expanded in c around 0 94.2%

      \[\leadsto \color{blue}{c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right)} \]
    5. Step-by-step derivation
      1. associate-*r/94.2%

        \[\leadsto c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - \color{blue}{\frac{0.5 \cdot 1}{b}}\right) \]
      2. metadata-eval94.2%

        \[\leadsto c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - \frac{\color{blue}{0.5}}{b}\right) \]
    6. Simplified94.2%

      \[\leadsto \color{blue}{c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - \frac{0.5}{b}\right)} \]
    7. Final simplification94.2%

      \[\leadsto c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - \frac{0.5}{b}\right) \]
    8. Add Preprocessing

    Alternative 8: 89.9% accurate, 23.2× speedup?

    \[\begin{array}{l} \\ c \cdot \frac{-0.5}{b} \end{array} \]
    (FPCore (a b c) :precision binary64 (* c (/ -0.5 b)))
    double code(double a, double b, double c) {
    	return c * (-0.5 / b);
    }
    
    real(8) function code(a, b, c)
        real(8), intent (in) :: a
        real(8), intent (in) :: b
        real(8), intent (in) :: c
        code = c * ((-0.5d0) / b)
    end function
    
    public static double code(double a, double b, double c) {
    	return c * (-0.5 / b);
    }
    
    def code(a, b, c):
    	return c * (-0.5 / b)
    
    function code(a, b, c)
    	return Float64(c * Float64(-0.5 / b))
    end
    
    function tmp = code(a, b, c)
    	tmp = c * (-0.5 / b);
    end
    
    code[a_, b_, c_] := N[(c * N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    c \cdot \frac{-0.5}{b}
    \end{array}
    
    Derivation
    1. Initial program 22.1%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Taylor expanded in a around 0 16.2%

      \[\leadsto \frac{\left(-b\right) + \color{blue}{\left(b + -1.5 \cdot \frac{a \cdot c}{b}\right)}}{3 \cdot a} \]
    4. Taylor expanded in b around 0 87.3%

      \[\leadsto \frac{\color{blue}{-1.5 \cdot \frac{a \cdot c}{b}}}{3 \cdot a} \]
    5. Step-by-step derivation
      1. associate-*r/87.2%

        \[\leadsto \frac{\color{blue}{\frac{-1.5 \cdot \left(a \cdot c\right)}{b}}}{3 \cdot a} \]
      2. *-commutative87.2%

        \[\leadsto \frac{\frac{-1.5 \cdot \color{blue}{\left(c \cdot a\right)}}{b}}{3 \cdot a} \]
      3. *-commutative87.2%

        \[\leadsto \frac{\frac{\color{blue}{\left(c \cdot a\right) \cdot -1.5}}{b}}{3 \cdot a} \]
      4. associate-*l*87.4%

        \[\leadsto \frac{\frac{\color{blue}{c \cdot \left(a \cdot -1.5\right)}}{b}}{3 \cdot a} \]
    6. Simplified87.4%

      \[\leadsto \frac{\color{blue}{\frac{c \cdot \left(a \cdot -1.5\right)}{b}}}{3 \cdot a} \]
    7. Taylor expanded in c around 0 87.8%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
    8. Step-by-step derivation
      1. *-commutative87.8%

        \[\leadsto \color{blue}{\frac{c}{b} \cdot -0.5} \]
      2. associate-*l/87.8%

        \[\leadsto \color{blue}{\frac{c \cdot -0.5}{b}} \]
      3. associate-/l*87.6%

        \[\leadsto \color{blue}{c \cdot \frac{-0.5}{b}} \]
    9. Simplified87.6%

      \[\leadsto \color{blue}{c \cdot \frac{-0.5}{b}} \]
    10. Final simplification87.6%

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

    Alternative 9: 90.2% accurate, 23.2× speedup?

    \[\begin{array}{l} \\ \frac{c \cdot -0.5}{b} \end{array} \]
    (FPCore (a b c) :precision binary64 (/ (* c -0.5) b))
    double code(double a, double b, double c) {
    	return (c * -0.5) / b;
    }
    
    real(8) function code(a, b, c)
        real(8), intent (in) :: a
        real(8), intent (in) :: b
        real(8), intent (in) :: c
        code = (c * (-0.5d0)) / b
    end function
    
    public static double code(double a, double b, double c) {
    	return (c * -0.5) / b;
    }
    
    def code(a, b, c):
    	return (c * -0.5) / b
    
    function code(a, b, c)
    	return Float64(Float64(c * -0.5) / b)
    end
    
    function tmp = code(a, b, c)
    	tmp = (c * -0.5) / b;
    end
    
    code[a_, b_, c_] := N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{c \cdot -0.5}{b}
    \end{array}
    
    Derivation
    1. Initial program 22.1%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Taylor expanded in b around inf 87.8%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
    4. Step-by-step derivation
      1. associate-*r/87.8%

        \[\leadsto \color{blue}{\frac{-0.5 \cdot c}{b}} \]
      2. *-commutative87.8%

        \[\leadsto \frac{\color{blue}{c \cdot -0.5}}{b} \]
    5. Simplified87.8%

      \[\leadsto \color{blue}{\frac{c \cdot -0.5}{b}} \]
    6. Final simplification87.8%

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

    Reproduce

    ?
    herbie shell --seed 2024069 
    (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)))