Quadratic roots, medium range

Percentage Accurate: 30.8% → 99.4%
Time: 8.0s
Alternatives: 5
Speedup: 29.0×

Specification

?
\[\left(\left(1.1102230246251565 \cdot 10^{-16} < a \land a < 9007199254740992\right) \land \left(1.1102230246251565 \cdot 10^{-16} < b \land b < 9007199254740992\right)\right) \land \left(1.1102230246251565 \cdot 10^{-16} < c \land c < 9007199254740992\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(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 5 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: 30.8% 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: 99.4% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := c \cdot \left(a \cdot -4\right)\\ \frac{\frac{t_0}{b + \sqrt{\mathsf{fma}\left(b, b, t_0\right)}}}{a \cdot 2} \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (* c (* a -4.0))))
   (/ (/ t_0 (+ b (sqrt (fma b b t_0)))) (* a 2.0))))
double code(double a, double b, double c) {
	double t_0 = c * (a * -4.0);
	return (t_0 / (b + sqrt(fma(b, b, t_0)))) / (a * 2.0);
}
function code(a, b, c)
	t_0 = Float64(c * Float64(a * -4.0))
	return Float64(Float64(t_0 / Float64(b + sqrt(fma(b, b, t_0)))) / Float64(a * 2.0))
end
code[a_, b_, c_] := Block[{t$95$0 = N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$0 / N[(b + N[Sqrt[N[(b * b + t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := c \cdot \left(a \cdot -4\right)\\
\frac{\frac{t_0}{b + \sqrt{\mathsf{fma}\left(b, b, t_0\right)}}}{a \cdot 2}
\end{array}
\end{array}
Derivation
  1. Initial program 31.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. Simplified31.4%

      \[\leadsto \color{blue}{\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{a \cdot 2}} \]
    2. Step-by-step derivation
      1. *-commutative31.4%

        \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \color{blue}{\left(-4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
      2. metadata-eval31.4%

        \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(\color{blue}{\left(-4\right)} \cdot a\right)\right)} - b}{a \cdot 2} \]
      3. distribute-lft-neg-in31.4%

        \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \color{blue}{\left(-4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
      4. distribute-rgt-neg-in31.4%

        \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{-c \cdot \left(4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
      5. *-commutative31.4%

        \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(4 \cdot a\right) \cdot c}\right)} - b}{a \cdot 2} \]
      6. fma-neg31.4%

        \[\leadsto \frac{\sqrt{\color{blue}{b \cdot b - \left(4 \cdot a\right) \cdot c}} - b}{a \cdot 2} \]
      7. associate-*l*31.4%

        \[\leadsto \frac{\sqrt{b \cdot b - \color{blue}{4 \cdot \left(a \cdot c\right)}} - b}{a \cdot 2} \]
    3. Applied egg-rr31.4%

      \[\leadsto \frac{\sqrt{\color{blue}{b \cdot b - 4 \cdot \left(a \cdot c\right)}} - b}{a \cdot 2} \]
    4. Step-by-step derivation
      1. flip--31.3%

        \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} \cdot \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} - b \cdot b}{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} + b}}}{a \cdot 2} \]
      2. add-sqr-sqrt32.3%

        \[\leadsto \frac{\frac{\color{blue}{\left(b \cdot b - 4 \cdot \left(a \cdot c\right)\right)} - b \cdot b}{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      3. cancel-sign-sub-inv32.3%

        \[\leadsto \frac{\frac{\color{blue}{\left(b \cdot b + \left(-4\right) \cdot \left(a \cdot c\right)\right)} - b \cdot b}{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      4. metadata-eval32.3%

        \[\leadsto \frac{\frac{\left(b \cdot b + \color{blue}{-4} \cdot \left(a \cdot c\right)\right) - b \cdot b}{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      5. cancel-sign-sub-inv32.3%

        \[\leadsto \frac{\frac{\left(b \cdot b + -4 \cdot \left(a \cdot c\right)\right) - b \cdot b}{\sqrt{\color{blue}{b \cdot b + \left(-4\right) \cdot \left(a \cdot c\right)}} + b}}{a \cdot 2} \]
      6. metadata-eval32.3%

        \[\leadsto \frac{\frac{\left(b \cdot b + -4 \cdot \left(a \cdot c\right)\right) - b \cdot b}{\sqrt{b \cdot b + \color{blue}{-4} \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
    5. Applied egg-rr32.3%

      \[\leadsto \frac{\color{blue}{\frac{\left(b \cdot b + -4 \cdot \left(a \cdot c\right)\right) - b \cdot b}{\sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)} + b}}}{a \cdot 2} \]
    6. Step-by-step derivation
      1. +-commutative32.3%

        \[\leadsto \frac{\frac{\color{blue}{\left(-4 \cdot \left(a \cdot c\right) + b \cdot b\right)} - b \cdot b}{\sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      2. associate--l+99.4%

        \[\leadsto \frac{\frac{\color{blue}{-4 \cdot \left(a \cdot c\right) + \left(b \cdot b - b \cdot b\right)}}{\sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      3. *-commutative99.4%

        \[\leadsto \frac{\frac{\color{blue}{\left(a \cdot c\right) \cdot -4} + \left(b \cdot b - b \cdot b\right)}{\sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      4. *-commutative99.4%

        \[\leadsto \frac{\frac{\color{blue}{\left(c \cdot a\right)} \cdot -4 + \left(b \cdot b - b \cdot b\right)}{\sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      5. associate-*l*99.4%

        \[\leadsto \frac{\frac{\color{blue}{c \cdot \left(a \cdot -4\right)} + \left(b \cdot b - b \cdot b\right)}{\sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      6. +-inverses99.4%

        \[\leadsto \frac{\frac{c \cdot \left(a \cdot -4\right) + \color{blue}{0}}{\sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
      7. +-commutative99.4%

        \[\leadsto \frac{\frac{c \cdot \left(a \cdot -4\right) + 0}{\color{blue}{b + \sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)}}}}{a \cdot 2} \]
      8. fma-def99.4%

        \[\leadsto \frac{\frac{c \cdot \left(a \cdot -4\right) + 0}{b + \sqrt{\color{blue}{\mathsf{fma}\left(b, b, -4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
      9. *-commutative99.4%

        \[\leadsto \frac{\frac{c \cdot \left(a \cdot -4\right) + 0}{b + \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot -4}\right)}}}{a \cdot 2} \]
      10. *-commutative99.4%

        \[\leadsto \frac{\frac{c \cdot \left(a \cdot -4\right) + 0}{b + \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(c \cdot a\right)} \cdot -4\right)}}}{a \cdot 2} \]
      11. associate-*l*99.4%

        \[\leadsto \frac{\frac{c \cdot \left(a \cdot -4\right) + 0}{b + \sqrt{\mathsf{fma}\left(b, b, \color{blue}{c \cdot \left(a \cdot -4\right)}\right)}}}{a \cdot 2} \]
    7. Simplified99.4%

      \[\leadsto \frac{\color{blue}{\frac{c \cdot \left(a \cdot -4\right) + 0}{b + \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)}}}}{a \cdot 2} \]
    8. Final simplification99.4%

      \[\leadsto \frac{\frac{c \cdot \left(a \cdot -4\right)}{b + \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)}}}{a \cdot 2} \]

    Alternative 2: 91.7% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := b \cdot b + -4 \cdot \left(c \cdot a\right)\\ \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2} \leq -150000:\\ \;\;\;\;\frac{\frac{t_0 - b \cdot b}{b + \sqrt{t_0}}}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)\\ \end{array} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (let* ((t_0 (+ (* b b) (* -4.0 (* c a)))))
       (if (<= (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)) -150000.0)
         (/ (/ (- t_0 (* b b)) (+ b (sqrt t_0))) (* a 2.0))
         (- (/ (- c) b) (* (/ a (pow b 3.0)) (* c c))))))
    double code(double a, double b, double c) {
    	double t_0 = (b * b) + (-4.0 * (c * a));
    	double tmp;
    	if (((sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -150000.0) {
    		tmp = ((t_0 - (b * b)) / (b + sqrt(t_0))) / (a * 2.0);
    	} else {
    		tmp = (-c / b) - ((a / pow(b, 3.0)) * (c * c));
    	}
    	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 = (b * b) + ((-4.0d0) * (c * a))
        if (((sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)) <= (-150000.0d0)) then
            tmp = ((t_0 - (b * b)) / (b + sqrt(t_0))) / (a * 2.0d0)
        else
            tmp = (-c / b) - ((a / (b ** 3.0d0)) * (c * c))
        end if
        code = tmp
    end function
    
    public static double code(double a, double b, double c) {
    	double t_0 = (b * b) + (-4.0 * (c * a));
    	double tmp;
    	if (((Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -150000.0) {
    		tmp = ((t_0 - (b * b)) / (b + Math.sqrt(t_0))) / (a * 2.0);
    	} else {
    		tmp = (-c / b) - ((a / Math.pow(b, 3.0)) * (c * c));
    	}
    	return tmp;
    }
    
    def code(a, b, c):
    	t_0 = (b * b) + (-4.0 * (c * a))
    	tmp = 0
    	if ((math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -150000.0:
    		tmp = ((t_0 - (b * b)) / (b + math.sqrt(t_0))) / (a * 2.0)
    	else:
    		tmp = (-c / b) - ((a / math.pow(b, 3.0)) * (c * c))
    	return tmp
    
    function code(a, b, c)
    	t_0 = Float64(Float64(b * b) + Float64(-4.0 * Float64(c * a)))
    	tmp = 0.0
    	if (Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)) <= -150000.0)
    		tmp = Float64(Float64(Float64(t_0 - Float64(b * b)) / Float64(b + sqrt(t_0))) / Float64(a * 2.0));
    	else
    		tmp = Float64(Float64(Float64(-c) / b) - Float64(Float64(a / (b ^ 3.0)) * Float64(c * c)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(a, b, c)
    	t_0 = (b * b) + (-4.0 * (c * a));
    	tmp = 0.0;
    	if (((sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -150000.0)
    		tmp = ((t_0 - (b * b)) / (b + sqrt(t_0))) / (a * 2.0);
    	else
    		tmp = (-c / b) - ((a / (b ^ 3.0)) * (c * c));
    	end
    	tmp_2 = tmp;
    end
    
    code[a_, b_, c_] := Block[{t$95$0 = N[(N[(b * b), $MachinePrecision] + N[(-4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], -150000.0], N[(N[(N[(t$95$0 - N[(b * b), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[t$95$0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[((-c) / b), $MachinePrecision] - N[(N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := b \cdot b + -4 \cdot \left(c \cdot a\right)\\
    \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2} \leq -150000:\\
    \;\;\;\;\frac{\frac{t_0 - b \cdot b}{b + \sqrt{t_0}}}{a \cdot 2}\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a)) < -1.5e5

      1. Initial program 83.2%

        \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      2. Step-by-step derivation
        1. Simplified83.3%

          \[\leadsto \color{blue}{\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{a \cdot 2}} \]
        2. Step-by-step derivation
          1. *-commutative83.3%

            \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \color{blue}{\left(-4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
          2. metadata-eval83.3%

            \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(\color{blue}{\left(-4\right)} \cdot a\right)\right)} - b}{a \cdot 2} \]
          3. distribute-lft-neg-in83.3%

            \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \color{blue}{\left(-4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
          4. distribute-rgt-neg-in83.3%

            \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{-c \cdot \left(4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
          5. *-commutative83.3%

            \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(4 \cdot a\right) \cdot c}\right)} - b}{a \cdot 2} \]
          6. fma-neg83.2%

            \[\leadsto \frac{\sqrt{\color{blue}{b \cdot b - \left(4 \cdot a\right) \cdot c}} - b}{a \cdot 2} \]
          7. associate-*l*83.2%

            \[\leadsto \frac{\sqrt{b \cdot b - \color{blue}{4 \cdot \left(a \cdot c\right)}} - b}{a \cdot 2} \]
        3. Applied egg-rr83.2%

          \[\leadsto \frac{\sqrt{\color{blue}{b \cdot b - 4 \cdot \left(a \cdot c\right)}} - b}{a \cdot 2} \]
        4. Step-by-step derivation
          1. flip--82.8%

            \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} \cdot \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} - b \cdot b}{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} + b}}}{a \cdot 2} \]
          2. add-sqr-sqrt84.4%

            \[\leadsto \frac{\frac{\color{blue}{\left(b \cdot b - 4 \cdot \left(a \cdot c\right)\right)} - b \cdot b}{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
          3. cancel-sign-sub-inv84.4%

            \[\leadsto \frac{\frac{\color{blue}{\left(b \cdot b + \left(-4\right) \cdot \left(a \cdot c\right)\right)} - b \cdot b}{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
          4. metadata-eval84.4%

            \[\leadsto \frac{\frac{\left(b \cdot b + \color{blue}{-4} \cdot \left(a \cdot c\right)\right) - b \cdot b}{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
          5. cancel-sign-sub-inv84.4%

            \[\leadsto \frac{\frac{\left(b \cdot b + -4 \cdot \left(a \cdot c\right)\right) - b \cdot b}{\sqrt{\color{blue}{b \cdot b + \left(-4\right) \cdot \left(a \cdot c\right)}} + b}}{a \cdot 2} \]
          6. metadata-eval84.4%

            \[\leadsto \frac{\frac{\left(b \cdot b + -4 \cdot \left(a \cdot c\right)\right) - b \cdot b}{\sqrt{b \cdot b + \color{blue}{-4} \cdot \left(a \cdot c\right)} + b}}{a \cdot 2} \]
        5. Applied egg-rr84.4%

          \[\leadsto \frac{\color{blue}{\frac{\left(b \cdot b + -4 \cdot \left(a \cdot c\right)\right) - b \cdot b}{\sqrt{b \cdot b + -4 \cdot \left(a \cdot c\right)} + b}}}{a \cdot 2} \]

        if -1.5e5 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a))

        1. Initial program 27.3%

          \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
        2. Taylor expanded in b around inf 92.3%

          \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
        3. Step-by-step derivation
          1. mul-1-neg92.3%

            \[\leadsto -1 \cdot \frac{c}{b} + \color{blue}{\left(-\frac{a \cdot {c}^{2}}{{b}^{3}}\right)} \]
          2. unsub-neg92.3%

            \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
          3. mul-1-neg92.3%

            \[\leadsto \color{blue}{\left(-\frac{c}{b}\right)} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
          4. distribute-neg-frac92.3%

            \[\leadsto \color{blue}{\frac{-c}{b}} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
          5. associate-/l*92.3%

            \[\leadsto \frac{-c}{b} - \color{blue}{\frac{a}{\frac{{b}^{3}}{{c}^{2}}}} \]
          6. associate-/r/92.3%

            \[\leadsto \frac{-c}{b} - \color{blue}{\frac{a}{{b}^{3}} \cdot {c}^{2}} \]
          7. unpow292.3%

            \[\leadsto \frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \color{blue}{\left(c \cdot c\right)} \]
        4. Simplified92.3%

          \[\leadsto \color{blue}{\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)} \]
      3. Recombined 2 regimes into one program.
      4. Final simplification91.7%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2} \leq -150000:\\ \;\;\;\;\frac{\frac{\left(b \cdot b + -4 \cdot \left(c \cdot a\right)\right) - b \cdot b}{b + \sqrt{b \cdot b + -4 \cdot \left(c \cdot a\right)}}}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)\\ \end{array} \]

      Alternative 3: 91.6% accurate, 0.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2} \leq -150000:\\ \;\;\;\;\frac{\sqrt{b \cdot b - 4 \cdot \left(c \cdot a\right)} - b}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)\\ \end{array} \end{array} \]
      (FPCore (a b c)
       :precision binary64
       (if (<= (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)) -150000.0)
         (/ (- (sqrt (- (* b b) (* 4.0 (* c a)))) b) (* a 2.0))
         (- (/ (- c) b) (* (/ a (pow b 3.0)) (* c c)))))
      double code(double a, double b, double c) {
      	double tmp;
      	if (((sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -150000.0) {
      		tmp = (sqrt(((b * b) - (4.0 * (c * a)))) - b) / (a * 2.0);
      	} else {
      		tmp = (-c / b) - ((a / pow(b, 3.0)) * (c * c));
      	}
      	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) :: tmp
          if (((sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)) <= (-150000.0d0)) then
              tmp = (sqrt(((b * b) - (4.0d0 * (c * a)))) - b) / (a * 2.0d0)
          else
              tmp = (-c / b) - ((a / (b ** 3.0d0)) * (c * c))
          end if
          code = tmp
      end function
      
      public static double code(double a, double b, double c) {
      	double tmp;
      	if (((Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -150000.0) {
      		tmp = (Math.sqrt(((b * b) - (4.0 * (c * a)))) - b) / (a * 2.0);
      	} else {
      		tmp = (-c / b) - ((a / Math.pow(b, 3.0)) * (c * c));
      	}
      	return tmp;
      }
      
      def code(a, b, c):
      	tmp = 0
      	if ((math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -150000.0:
      		tmp = (math.sqrt(((b * b) - (4.0 * (c * a)))) - b) / (a * 2.0)
      	else:
      		tmp = (-c / b) - ((a / math.pow(b, 3.0)) * (c * c))
      	return tmp
      
      function code(a, b, c)
      	tmp = 0.0
      	if (Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)) <= -150000.0)
      		tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(c * a)))) - b) / Float64(a * 2.0));
      	else
      		tmp = Float64(Float64(Float64(-c) / b) - Float64(Float64(a / (b ^ 3.0)) * Float64(c * c)));
      	end
      	return tmp
      end
      
      function tmp_2 = code(a, b, c)
      	tmp = 0.0;
      	if (((sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)) <= -150000.0)
      		tmp = (sqrt(((b * b) - (4.0 * (c * a)))) - b) / (a * 2.0);
      	else
      		tmp = (-c / b) - ((a / (b ^ 3.0)) * (c * c));
      	end
      	tmp_2 = tmp;
      end
      
      code[a_, b_, c_] := If[LessEqual[N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], -150000.0], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[((-c) / b), $MachinePrecision] - N[(N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2} \leq -150000:\\
      \;\;\;\;\frac{\sqrt{b \cdot b - 4 \cdot \left(c \cdot a\right)} - b}{a \cdot 2}\\
      
      \mathbf{else}:\\
      \;\;\;\;\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a)) < -1.5e5

        1. Initial program 83.2%

          \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
        2. Step-by-step derivation
          1. Simplified83.3%

            \[\leadsto \color{blue}{\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{a \cdot 2}} \]
          2. Step-by-step derivation
            1. *-commutative83.3%

              \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \color{blue}{\left(-4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
            2. metadata-eval83.3%

              \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(\color{blue}{\left(-4\right)} \cdot a\right)\right)} - b}{a \cdot 2} \]
            3. distribute-lft-neg-in83.3%

              \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \color{blue}{\left(-4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
            4. distribute-rgt-neg-in83.3%

              \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{-c \cdot \left(4 \cdot a\right)}\right)} - b}{a \cdot 2} \]
            5. *-commutative83.3%

              \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(4 \cdot a\right) \cdot c}\right)} - b}{a \cdot 2} \]
            6. fma-neg83.2%

              \[\leadsto \frac{\sqrt{\color{blue}{b \cdot b - \left(4 \cdot a\right) \cdot c}} - b}{a \cdot 2} \]
            7. associate-*l*83.2%

              \[\leadsto \frac{\sqrt{b \cdot b - \color{blue}{4 \cdot \left(a \cdot c\right)}} - b}{a \cdot 2} \]
          3. Applied egg-rr83.2%

            \[\leadsto \frac{\sqrt{\color{blue}{b \cdot b - 4 \cdot \left(a \cdot c\right)}} - b}{a \cdot 2} \]

          if -1.5e5 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a))

          1. Initial program 27.3%

            \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
          2. Taylor expanded in b around inf 92.3%

            \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
          3. Step-by-step derivation
            1. mul-1-neg92.3%

              \[\leadsto -1 \cdot \frac{c}{b} + \color{blue}{\left(-\frac{a \cdot {c}^{2}}{{b}^{3}}\right)} \]
            2. unsub-neg92.3%

              \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
            3. mul-1-neg92.3%

              \[\leadsto \color{blue}{\left(-\frac{c}{b}\right)} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
            4. distribute-neg-frac92.3%

              \[\leadsto \color{blue}{\frac{-c}{b}} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
            5. associate-/l*92.3%

              \[\leadsto \frac{-c}{b} - \color{blue}{\frac{a}{\frac{{b}^{3}}{{c}^{2}}}} \]
            6. associate-/r/92.3%

              \[\leadsto \frac{-c}{b} - \color{blue}{\frac{a}{{b}^{3}} \cdot {c}^{2}} \]
            7. unpow292.3%

              \[\leadsto \frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \color{blue}{\left(c \cdot c\right)} \]
          4. Simplified92.3%

            \[\leadsto \color{blue}{\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)} \]
        3. Recombined 2 regimes into one program.
        4. Final simplification91.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2} \leq -150000:\\ \;\;\;\;\frac{\sqrt{b \cdot b - 4 \cdot \left(c \cdot a\right)} - b}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)\\ \end{array} \]

        Alternative 4: 91.2% accurate, 1.0× speedup?

        \[\begin{array}{l} \\ \frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right) \end{array} \]
        (FPCore (a b c)
         :precision binary64
         (- (/ (- c) b) (* (/ a (pow b 3.0)) (* c c))))
        double code(double a, double b, double c) {
        	return (-c / b) - ((a / pow(b, 3.0)) * (c * c));
        }
        
        real(8) function code(a, b, c)
            real(8), intent (in) :: a
            real(8), intent (in) :: b
            real(8), intent (in) :: c
            code = (-c / b) - ((a / (b ** 3.0d0)) * (c * c))
        end function
        
        public static double code(double a, double b, double c) {
        	return (-c / b) - ((a / Math.pow(b, 3.0)) * (c * c));
        }
        
        def code(a, b, c):
        	return (-c / b) - ((a / math.pow(b, 3.0)) * (c * c))
        
        function code(a, b, c)
        	return Float64(Float64(Float64(-c) / b) - Float64(Float64(a / (b ^ 3.0)) * Float64(c * c)))
        end
        
        function tmp = code(a, b, c)
        	tmp = (-c / b) - ((a / (b ^ 3.0)) * (c * c));
        end
        
        code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)
        \end{array}
        
        Derivation
        1. Initial program 31.4%

          \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
        2. Taylor expanded in b around inf 89.7%

          \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
        3. Step-by-step derivation
          1. mul-1-neg89.7%

            \[\leadsto -1 \cdot \frac{c}{b} + \color{blue}{\left(-\frac{a \cdot {c}^{2}}{{b}^{3}}\right)} \]
          2. unsub-neg89.7%

            \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
          3. mul-1-neg89.7%

            \[\leadsto \color{blue}{\left(-\frac{c}{b}\right)} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
          4. distribute-neg-frac89.7%

            \[\leadsto \color{blue}{\frac{-c}{b}} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
          5. associate-/l*89.7%

            \[\leadsto \frac{-c}{b} - \color{blue}{\frac{a}{\frac{{b}^{3}}{{c}^{2}}}} \]
          6. associate-/r/89.7%

            \[\leadsto \frac{-c}{b} - \color{blue}{\frac{a}{{b}^{3}} \cdot {c}^{2}} \]
          7. unpow289.7%

            \[\leadsto \frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \color{blue}{\left(c \cdot c\right)} \]
        4. Simplified89.7%

          \[\leadsto \color{blue}{\frac{-c}{b} - \frac{a}{{b}^{3}} \cdot \left(c \cdot c\right)} \]
        5. Final simplification89.7%

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

        Alternative 5: 81.8% accurate, 29.0× speedup?

        \[\begin{array}{l} \\ \frac{-c}{b} \end{array} \]
        (FPCore (a b c) :precision binary64 (/ (- c) b))
        double code(double a, double b, double c) {
        	return -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 = -c / b
        end function
        
        public static double code(double a, double b, double c) {
        	return -c / b;
        }
        
        def code(a, b, c):
        	return -c / b
        
        function code(a, b, c)
        	return Float64(Float64(-c) / b)
        end
        
        function tmp = code(a, b, c)
        	tmp = -c / b;
        end
        
        code[a_, b_, c_] := N[((-c) / b), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \frac{-c}{b}
        \end{array}
        
        Derivation
        1. Initial program 31.4%

          \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
        2. Taylor expanded in b around inf 80.7%

          \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
        3. Step-by-step derivation
          1. mul-1-neg80.7%

            \[\leadsto \color{blue}{-\frac{c}{b}} \]
          2. distribute-neg-frac80.7%

            \[\leadsto \color{blue}{\frac{-c}{b}} \]
        4. Simplified80.7%

          \[\leadsto \color{blue}{\frac{-c}{b}} \]
        5. Final simplification80.7%

          \[\leadsto \frac{-c}{b} \]

        Reproduce

        ?
        herbie shell --seed 2023293 
        (FPCore (a b c)
          :name "Quadratic roots, medium range"
          :precision binary64
          :pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
          (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))