The quadratic formula (r1)

Percentage Accurate: 52.4% → 85.2%
Time: 11.6s
Alternatives: 9
Speedup: 2.5×

Specification

?
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * 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) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \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: 52.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * 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) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}

Alternative 1: 85.2% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.1 \cdot 10^{+158}:\\ \;\;\;\;-\frac{b}{a}\\ \mathbf{elif}\;b \leq 3.1 \cdot 10^{-86}:\\ \;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)} - b}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{c}{b}, a \cdot \frac{c}{b}, c\right)}{-b}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= b -1.1e+158)
   (- (/ b a))
   (if (<= b 3.1e-86)
     (/ (- (sqrt (- (* b b) (* c (* 4.0 a)))) b) (* a 2.0))
     (/ (fma (/ c b) (* a (/ c b)) c) (- b)))))
double code(double a, double b, double c) {
	double tmp;
	if (b <= -1.1e+158) {
		tmp = -(b / a);
	} else if (b <= 3.1e-86) {
		tmp = (sqrt(((b * b) - (c * (4.0 * a)))) - b) / (a * 2.0);
	} else {
		tmp = fma((c / b), (a * (c / b)), c) / -b;
	}
	return tmp;
}
function code(a, b, c)
	tmp = 0.0
	if (b <= -1.1e+158)
		tmp = Float64(-Float64(b / a));
	elseif (b <= 3.1e-86)
		tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(4.0 * a)))) - b) / Float64(a * 2.0));
	else
		tmp = Float64(fma(Float64(c / b), Float64(a * Float64(c / b)), c) / Float64(-b));
	end
	return tmp
end
code[a_, b_, c_] := If[LessEqual[b, -1.1e+158], (-N[(b / a), $MachinePrecision]), If[LessEqual[b, 3.1e-86], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(4.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(N[(c / b), $MachinePrecision] * N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision] / (-b)), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.1 \cdot 10^{+158}:\\
\;\;\;\;-\frac{b}{a}\\

\mathbf{elif}\;b \leq 3.1 \cdot 10^{-86}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)} - b}{a \cdot 2}\\

\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(\frac{c}{b}, a \cdot \frac{c}{b}, c\right)}{-b}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -1.1000000000000001e158

    1. Initial program 27.2%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Add Preprocessing
    3. Taylor expanded in b around -inf

      \[\leadsto \color{blue}{-1 \cdot \frac{b}{a}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{b}{a}\right)} \]
      2. distribute-neg-frac2N/A

        \[\leadsto \color{blue}{\frac{b}{\mathsf{neg}\left(a\right)}} \]
      3. mul-1-negN/A

        \[\leadsto \frac{b}{\color{blue}{-1 \cdot a}} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{b}{-1 \cdot a}} \]
      5. mul-1-negN/A

        \[\leadsto \frac{b}{\color{blue}{\mathsf{neg}\left(a\right)}} \]
      6. lower-neg.f6497.9

        \[\leadsto \frac{b}{\color{blue}{-a}} \]
    5. Applied rewrites97.9%

      \[\leadsto \color{blue}{\frac{b}{-a}} \]

    if -1.1000000000000001e158 < b < 3.09999999999999989e-86

    1. Initial program 83.3%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Add Preprocessing

    if 3.09999999999999989e-86 < b

    1. Initial program 16.6%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Add Preprocessing
    3. Taylor expanded in b around -inf

      \[\leadsto \color{blue}{-1 \cdot \frac{b}{a}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{b}{a}\right)} \]
      2. distribute-neg-frac2N/A

        \[\leadsto \color{blue}{\frac{b}{\mathsf{neg}\left(a\right)}} \]
      3. mul-1-negN/A

        \[\leadsto \frac{b}{\color{blue}{-1 \cdot a}} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{b}{-1 \cdot a}} \]
      5. mul-1-negN/A

        \[\leadsto \frac{b}{\color{blue}{\mathsf{neg}\left(a\right)}} \]
      6. lower-neg.f642.8

        \[\leadsto \frac{b}{\color{blue}{-a}} \]
    5. Applied rewrites2.8%

      \[\leadsto \color{blue}{\frac{b}{-a}} \]
    6. Taylor expanded in b around inf

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

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

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

        \[\leadsto \frac{\color{blue}{\left(\mathsf{neg}\left(\frac{a \cdot {c}^{2}}{{b}^{2}}\right)\right)} + -1 \cdot c}{b} \]
      4. mul-1-negN/A

        \[\leadsto \frac{\left(\mathsf{neg}\left(\frac{a \cdot {c}^{2}}{{b}^{2}}\right)\right) + \color{blue}{\left(\mathsf{neg}\left(c\right)\right)}}{b} \]
      5. distribute-neg-outN/A

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

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

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

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

        \[\leadsto \frac{\mathsf{neg}\left(\mathsf{fma}\left(a, \color{blue}{\frac{{c}^{2}}{{b}^{2}}}, c\right)\right)}{b} \]
      10. unpow2N/A

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

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

        \[\leadsto \frac{\mathsf{neg}\left(\mathsf{fma}\left(a, \frac{c \cdot c}{\color{blue}{b \cdot b}}, c\right)\right)}{b} \]
      13. lower-*.f6475.2

        \[\leadsto \frac{-\mathsf{fma}\left(a, \frac{c \cdot c}{\color{blue}{b \cdot b}}, c\right)}{b} \]
    8. Applied rewrites75.2%

      \[\leadsto \color{blue}{\frac{-\mathsf{fma}\left(a, \frac{c \cdot c}{b \cdot b}, c\right)}{b}} \]
    9. Step-by-step derivation
      1. Applied rewrites90.0%

        \[\leadsto \frac{-\mathsf{fma}\left(\frac{c}{b}, \frac{c}{b} \cdot a, c\right)}{b} \]
    10. Recombined 3 regimes into one program.
    11. Final simplification88.1%

      \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.1 \cdot 10^{+158}:\\ \;\;\;\;-\frac{b}{a}\\ \mathbf{elif}\;b \leq 3.1 \cdot 10^{-86}:\\ \;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)} - b}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{c}{b}, a \cdot \frac{c}{b}, c\right)}{-b}\\ \end{array} \]
    12. Add Preprocessing

    Alternative 2: 85.1% accurate, 0.8× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.1 \cdot 10^{+158}:\\ \;\;\;\;-\frac{b}{a}\\ \mathbf{elif}\;b \leq 3.1 \cdot 10^{-86}:\\ \;\;\;\;\frac{-0.5}{a} \cdot \left(b - \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{c}{b}, a \cdot \frac{c}{b}, c\right)}{-b}\\ \end{array} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (if (<= b -1.1e+158)
       (- (/ b a))
       (if (<= b 3.1e-86)
         (* (/ -0.5 a) (- b (sqrt (fma a (* c -4.0) (* b b)))))
         (/ (fma (/ c b) (* a (/ c b)) c) (- b)))))
    double code(double a, double b, double c) {
    	double tmp;
    	if (b <= -1.1e+158) {
    		tmp = -(b / a);
    	} else if (b <= 3.1e-86) {
    		tmp = (-0.5 / a) * (b - sqrt(fma(a, (c * -4.0), (b * b))));
    	} else {
    		tmp = fma((c / b), (a * (c / b)), c) / -b;
    	}
    	return tmp;
    }
    
    function code(a, b, c)
    	tmp = 0.0
    	if (b <= -1.1e+158)
    		tmp = Float64(-Float64(b / a));
    	elseif (b <= 3.1e-86)
    		tmp = Float64(Float64(-0.5 / a) * Float64(b - sqrt(fma(a, Float64(c * -4.0), Float64(b * b)))));
    	else
    		tmp = Float64(fma(Float64(c / b), Float64(a * Float64(c / b)), c) / Float64(-b));
    	end
    	return tmp
    end
    
    code[a_, b_, c_] := If[LessEqual[b, -1.1e+158], (-N[(b / a), $MachinePrecision]), If[LessEqual[b, 3.1e-86], N[(N[(-0.5 / a), $MachinePrecision] * N[(b - N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(c / b), $MachinePrecision] * N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision] / (-b)), $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;b \leq -1.1 \cdot 10^{+158}:\\
    \;\;\;\;-\frac{b}{a}\\
    
    \mathbf{elif}\;b \leq 3.1 \cdot 10^{-86}:\\
    \;\;\;\;\frac{-0.5}{a} \cdot \left(b - \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{\mathsf{fma}\left(\frac{c}{b}, a \cdot \frac{c}{b}, c\right)}{-b}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if b < -1.1000000000000001e158

      1. Initial program 39.1%

        \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      2. Add Preprocessing
      3. Taylor expanded in b around -inf

        \[\leadsto \color{blue}{-1 \cdot \frac{b}{a}} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{b}{a}\right)} \]
        2. distribute-neg-frac2N/A

          \[\leadsto \color{blue}{\frac{b}{\mathsf{neg}\left(a\right)}} \]
        3. mul-1-negN/A

          \[\leadsto \frac{b}{\color{blue}{-1 \cdot a}} \]
        4. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{b}{-1 \cdot a}} \]
        5. mul-1-negN/A

          \[\leadsto \frac{b}{\color{blue}{\mathsf{neg}\left(a\right)}} \]
        6. lower-neg.f6498.0

          \[\leadsto \frac{b}{\color{blue}{-a}} \]
      5. Applied rewrites98.0%

        \[\leadsto \color{blue}{\frac{b}{-a}} \]

      if -1.1000000000000001e158 < b < 3.09999999999999989e-86

      1. Initial program 81.5%

        \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      2. Add Preprocessing
      3. Applied rewrites81.3%

        \[\leadsto \color{blue}{\frac{-0.5}{a} \cdot \left(b - \sqrt{\mathsf{fma}\left(a, -4 \cdot c, b \cdot b\right)}\right)} \]

      if 3.09999999999999989e-86 < b

      1. Initial program 18.7%

        \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      2. Add Preprocessing
      3. Taylor expanded in b around -inf

        \[\leadsto \color{blue}{-1 \cdot \frac{b}{a}} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{b}{a}\right)} \]
        2. distribute-neg-frac2N/A

          \[\leadsto \color{blue}{\frac{b}{\mathsf{neg}\left(a\right)}} \]
        3. mul-1-negN/A

          \[\leadsto \frac{b}{\color{blue}{-1 \cdot a}} \]
        4. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{b}{-1 \cdot a}} \]
        5. mul-1-negN/A

          \[\leadsto \frac{b}{\color{blue}{\mathsf{neg}\left(a\right)}} \]
        6. lower-neg.f642.6

          \[\leadsto \frac{b}{\color{blue}{-a}} \]
      5. Applied rewrites2.6%

        \[\leadsto \color{blue}{\frac{b}{-a}} \]
      6. Taylor expanded in b around inf

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

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

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

          \[\leadsto \frac{\color{blue}{\left(\mathsf{neg}\left(\frac{a \cdot {c}^{2}}{{b}^{2}}\right)\right)} + -1 \cdot c}{b} \]
        4. mul-1-negN/A

          \[\leadsto \frac{\left(\mathsf{neg}\left(\frac{a \cdot {c}^{2}}{{b}^{2}}\right)\right) + \color{blue}{\left(\mathsf{neg}\left(c\right)\right)}}{b} \]
        5. distribute-neg-outN/A

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

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

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

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

          \[\leadsto \frac{\mathsf{neg}\left(\mathsf{fma}\left(a, \color{blue}{\frac{{c}^{2}}{{b}^{2}}}, c\right)\right)}{b} \]
        10. unpow2N/A

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

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

          \[\leadsto \frac{\mathsf{neg}\left(\mathsf{fma}\left(a, \frac{c \cdot c}{\color{blue}{b \cdot b}}, c\right)\right)}{b} \]
        13. lower-*.f6470.7

          \[\leadsto \frac{-\mathsf{fma}\left(a, \frac{c \cdot c}{\color{blue}{b \cdot b}}, c\right)}{b} \]
      8. Applied rewrites70.7%

        \[\leadsto \color{blue}{\frac{-\mathsf{fma}\left(a, \frac{c \cdot c}{b \cdot b}, c\right)}{b}} \]
      9. Step-by-step derivation
        1. Applied rewrites84.6%

          \[\leadsto \frac{-\mathsf{fma}\left(\frac{c}{b}, \frac{c}{b} \cdot a, c\right)}{b} \]
      10. Recombined 3 regimes into one program.
      11. Final simplification85.1%

        \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.1 \cdot 10^{+158}:\\ \;\;\;\;-\frac{b}{a}\\ \mathbf{elif}\;b \leq 3.1 \cdot 10^{-86}:\\ \;\;\;\;\frac{-0.5}{a} \cdot \left(b - \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{c}{b}, a \cdot \frac{c}{b}, c\right)}{-b}\\ \end{array} \]
      12. Add Preprocessing

      Developer Target 1: 70.4% accurate, 0.7× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\\ \mathbf{if}\;b < 0:\\ \;\;\;\;\frac{\left(-b\right) + t\_0}{2 \cdot a}\\ \mathbf{else}:\\ \;\;\;\;\frac{c}{a \cdot \frac{\left(-b\right) - t\_0}{2 \cdot a}}\\ \end{array} \end{array} \]
      (FPCore (a b c)
       :precision binary64
       (let* ((t_0 (sqrt (- (* b b) (* (* 4.0 a) c)))))
         (if (< b 0.0)
           (/ (+ (- b) t_0) (* 2.0 a))
           (/ c (* a (/ (- (- b) t_0) (* 2.0 a)))))))
      double code(double a, double b, double c) {
      	double t_0 = sqrt(((b * b) - ((4.0 * a) * c)));
      	double tmp;
      	if (b < 0.0) {
      		tmp = (-b + t_0) / (2.0 * a);
      	} else {
      		tmp = c / (a * ((-b - t_0) / (2.0 * a)));
      	}
      	return tmp;
      }
      
      real(8) function code(a, b, c)
          real(8), intent (in) :: a
          real(8), intent (in) :: b
          real(8), intent (in) :: c
          real(8) :: t_0
          real(8) :: tmp
          t_0 = sqrt(((b * b) - ((4.0d0 * a) * c)))
          if (b < 0.0d0) then
              tmp = (-b + t_0) / (2.0d0 * a)
          else
              tmp = c / (a * ((-b - t_0) / (2.0d0 * a)))
          end if
          code = tmp
      end function
      
      public static double code(double a, double b, double c) {
      	double t_0 = Math.sqrt(((b * b) - ((4.0 * a) * c)));
      	double tmp;
      	if (b < 0.0) {
      		tmp = (-b + t_0) / (2.0 * a);
      	} else {
      		tmp = c / (a * ((-b - t_0) / (2.0 * a)));
      	}
      	return tmp;
      }
      
      def code(a, b, c):
      	t_0 = math.sqrt(((b * b) - ((4.0 * a) * c)))
      	tmp = 0
      	if b < 0.0:
      		tmp = (-b + t_0) / (2.0 * a)
      	else:
      		tmp = c / (a * ((-b - t_0) / (2.0 * a)))
      	return tmp
      
      function code(a, b, c)
      	t_0 = sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))
      	tmp = 0.0
      	if (b < 0.0)
      		tmp = Float64(Float64(Float64(-b) + t_0) / Float64(2.0 * a));
      	else
      		tmp = Float64(c / Float64(a * Float64(Float64(Float64(-b) - t_0) / Float64(2.0 * a))));
      	end
      	return tmp
      end
      
      function tmp_2 = code(a, b, c)
      	t_0 = sqrt(((b * b) - ((4.0 * a) * c)));
      	tmp = 0.0;
      	if (b < 0.0)
      		tmp = (-b + t_0) / (2.0 * a);
      	else
      		tmp = c / (a * ((-b - t_0) / (2.0 * a)));
      	end
      	tmp_2 = tmp;
      end
      
      code[a_, b_, c_] := Block[{t$95$0 = N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[Less[b, 0.0], N[(N[((-b) + t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], N[(c / N[(a * N[(N[((-b) - t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\\
      \mathbf{if}\;b < 0:\\
      \;\;\;\;\frac{\left(-b\right) + t\_0}{2 \cdot a}\\
      
      \mathbf{else}:\\
      \;\;\;\;\frac{c}{a \cdot \frac{\left(-b\right) - t\_0}{2 \cdot a}}\\
      
      
      \end{array}
      \end{array}
      

      Reproduce

      ?
      herbie shell --seed 2024225 
      (FPCore (a b c)
        :name "The quadratic formula (r1)"
        :precision binary64
      
        :alt
        (! :herbie-platform default (let ((d (- (* b b) (* (* 4 a) c)))) (let ((r1 (/ (+ (- b) (sqrt d)) (* 2 a)))) (let ((r2 (/ (- (- b) (sqrt d)) (* 2 a)))) (if (< b 0) r1 (/ c (* a r2)))))))
      
        (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))