The quadratic formula (r2)

Percentage Accurate: 51.7% → 85.6%
Time: 12.3s
Alternatives: 8
Speedup: 19.1×

Specification

?
\[\begin{array}{l} \\ \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \end{array} \]
(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(4.0 * Float64(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[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{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 8 alternatives:

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

Initial Program: 51.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \end{array} \]
(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(4.0 * Float64(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[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

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

Alternative 1: 85.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -2.45 \cdot 10^{-48}:\\ \;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\ \mathbf{elif}\;b \leq 4.6 \cdot 10^{+94}:\\ \;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)}}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-b}{a}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= b -2.45e-48)
   (* -0.5 (/ 1.0 (+ (* -0.5 (/ a b)) (* 0.5 (/ b c)))))
   (if (<= b 4.6e+94)
     (/ (- (- b) (sqrt (- (* b b) (* c (* a 4.0))))) (* a 2.0))
     (/ (- b) a))))
double code(double a, double b, double c) {
	double tmp;
	if (b <= -2.45e-48) {
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	} else if (b <= 4.6e+94) {
		tmp = (-b - sqrt(((b * b) - (c * (a * 4.0))))) / (a * 2.0);
	} else {
		tmp = -b / 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) :: tmp
    if (b <= (-2.45d-48)) then
        tmp = (-0.5d0) * (1.0d0 / (((-0.5d0) * (a / b)) + (0.5d0 * (b / c))))
    else if (b <= 4.6d+94) then
        tmp = (-b - sqrt(((b * b) - (c * (a * 4.0d0))))) / (a * 2.0d0)
    else
        tmp = -b / a
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double tmp;
	if (b <= -2.45e-48) {
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	} else if (b <= 4.6e+94) {
		tmp = (-b - Math.sqrt(((b * b) - (c * (a * 4.0))))) / (a * 2.0);
	} else {
		tmp = -b / a;
	}
	return tmp;
}
def code(a, b, c):
	tmp = 0
	if b <= -2.45e-48:
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))))
	elif b <= 4.6e+94:
		tmp = (-b - math.sqrt(((b * b) - (c * (a * 4.0))))) / (a * 2.0)
	else:
		tmp = -b / a
	return tmp
function code(a, b, c)
	tmp = 0.0
	if (b <= -2.45e-48)
		tmp = Float64(-0.5 * Float64(1.0 / Float64(Float64(-0.5 * Float64(a / b)) + Float64(0.5 * Float64(b / c)))));
	elseif (b <= 4.6e+94)
		tmp = Float64(Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0))))) / Float64(a * 2.0));
	else
		tmp = Float64(Float64(-b) / a);
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	tmp = 0.0;
	if (b <= -2.45e-48)
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	elseif (b <= 4.6e+94)
		tmp = (-b - sqrt(((b * b) - (c * (a * 4.0))))) / (a * 2.0);
	else
		tmp = -b / a;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := If[LessEqual[b, -2.45e-48], N[(-0.5 * N[(1.0 / N[(N[(-0.5 * N[(a / b), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 4.6e+94], N[(N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-b) / a), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -2.45 \cdot 10^{-48}:\\
\;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\

\mathbf{elif}\;b \leq 4.6 \cdot 10^{+94}:\\
\;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)}}{a \cdot 2}\\

\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -2.4500000000000001e-48

    1. Initial program 18.8%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. sub-neg18.8%

        \[\leadsto \frac{\color{blue}{\left(-b\right) + \left(-\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      2. distribute-neg-out18.8%

        \[\leadsto \frac{\color{blue}{-\left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      3. neg-mul-118.8%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      4. times-frac18.8%

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a}} \]
      5. metadata-eval18.8%

        \[\leadsto \color{blue}{-0.5} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a} \]
      6. sub-neg18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{b \cdot b + \left(-4 \cdot \left(a \cdot c\right)\right)}}}{a} \]
      7. +-commutative18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(-4 \cdot \left(a \cdot c\right)\right) + b \cdot b}}}{a} \]
      8. distribute-rgt-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{4 \cdot \left(-a \cdot c\right)} + b \cdot b}}{a} \]
      9. distribute-rgt-neg-out18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{4 \cdot \color{blue}{\left(a \cdot \left(-c\right)\right)} + b \cdot b}}{a} \]
      10. *-commutative18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(a \cdot \left(-c\right)\right) \cdot 4} + b \cdot b}}{a} \]
      11. associate-*l*18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{a \cdot \left(\left(-c\right) \cdot 4\right)} + b \cdot b}}{a} \]
      12. fma-def18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\mathsf{fma}\left(a, \left(-c\right) \cdot 4, b \cdot b\right)}}}{a} \]
      13. distribute-lft-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{-c \cdot 4}, b \cdot b\right)}}{a} \]
      14. distribute-rgt-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{c \cdot \left(-4\right)}, b \cdot b\right)}}{a} \]
      15. metadata-eval18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot \color{blue}{-4}, b \cdot b\right)}}{a} \]
    3. Simplified18.8%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}{a}} \]
    4. Step-by-step derivation
      1. clear-num18.8%

        \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}}} \]
      2. inv-pow18.8%

        \[\leadsto -0.5 \cdot \color{blue}{{\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}\right)}^{-1}} \]
      3. pow218.8%

        \[\leadsto -0.5 \cdot {\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, \color{blue}{{b}^{2}}\right)}}\right)}^{-1} \]
    5. Applied egg-rr18.8%

      \[\leadsto -0.5 \cdot \color{blue}{{\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}\right)}^{-1}} \]
    6. Step-by-step derivation
      1. unpow-118.8%

        \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}}} \]
    7. Simplified18.8%

      \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}}} \]
    8. Taylor expanded in b around -inf 88.6%

      \[\leadsto -0.5 \cdot \frac{1}{\color{blue}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}} \]

    if -2.4500000000000001e-48 < b < 4.5999999999999999e94

    1. Initial program 83.4%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative83.4%

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

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

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

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*83.4%

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

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified83.4%

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

    if 4.5999999999999999e94 < b

    1. Initial program 54.2%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
      2. sqr-neg54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
      3. *-commutative54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
      4. sqr-neg54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
      6. *-commutative54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified54.2%

      \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around inf 97.1%

      \[\leadsto \color{blue}{-1 \cdot \frac{b}{a}} \]
    5. Step-by-step derivation
      1. associate-*r/97.1%

        \[\leadsto \color{blue}{\frac{-1 \cdot b}{a}} \]
      2. mul-1-neg97.1%

        \[\leadsto \frac{\color{blue}{-b}}{a} \]
    6. Simplified97.1%

      \[\leadsto \color{blue}{\frac{-b}{a}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -2.45 \cdot 10^{-48}:\\ \;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\ \mathbf{elif}\;b \leq 4.6 \cdot 10^{+94}:\\ \;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)}}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-b}{a}\\ \end{array} \]

Alternative 2: 85.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -3 \cdot 10^{-47}:\\ \;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\ \mathbf{elif}\;b \leq 5.5 \cdot 10^{+96}:\\ \;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-b}{a}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= b -3e-47)
   (* -0.5 (/ 1.0 (+ (* -0.5 (/ a b)) (* 0.5 (/ b c)))))
   (if (<= b 5.5e+96)
     (/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* a 2.0))
     (/ (- b) a))))
double code(double a, double b, double c) {
	double tmp;
	if (b <= -3e-47) {
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	} else if (b <= 5.5e+96) {
		tmp = (-b - sqrt(((b * b) - (4.0 * (a * c))))) / (a * 2.0);
	} else {
		tmp = -b / 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) :: tmp
    if (b <= (-3d-47)) then
        tmp = (-0.5d0) * (1.0d0 / (((-0.5d0) * (a / b)) + (0.5d0 * (b / c))))
    else if (b <= 5.5d+96) then
        tmp = (-b - sqrt(((b * b) - (4.0d0 * (a * c))))) / (a * 2.0d0)
    else
        tmp = -b / a
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double tmp;
	if (b <= -3e-47) {
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	} else if (b <= 5.5e+96) {
		tmp = (-b - Math.sqrt(((b * b) - (4.0 * (a * c))))) / (a * 2.0);
	} else {
		tmp = -b / a;
	}
	return tmp;
}
def code(a, b, c):
	tmp = 0
	if b <= -3e-47:
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))))
	elif b <= 5.5e+96:
		tmp = (-b - math.sqrt(((b * b) - (4.0 * (a * c))))) / (a * 2.0)
	else:
		tmp = -b / a
	return tmp
function code(a, b, c)
	tmp = 0.0
	if (b <= -3e-47)
		tmp = Float64(-0.5 * Float64(1.0 / Float64(Float64(-0.5 * Float64(a / b)) + Float64(0.5 * Float64(b / c)))));
	elseif (b <= 5.5e+96)
		tmp = Float64(Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(a * c))))) / Float64(a * 2.0));
	else
		tmp = Float64(Float64(-b) / a);
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	tmp = 0.0;
	if (b <= -3e-47)
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	elseif (b <= 5.5e+96)
		tmp = (-b - sqrt(((b * b) - (4.0 * (a * c))))) / (a * 2.0);
	else
		tmp = -b / a;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := If[LessEqual[b, -3e-47], N[(-0.5 * N[(1.0 / N[(N[(-0.5 * N[(a / b), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 5.5e+96], N[(N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-b) / a), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -3 \cdot 10^{-47}:\\
\;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\

\mathbf{elif}\;b \leq 5.5 \cdot 10^{+96}:\\
\;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a \cdot 2}\\

\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -3.00000000000000017e-47

    1. Initial program 18.8%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. sub-neg18.8%

        \[\leadsto \frac{\color{blue}{\left(-b\right) + \left(-\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      2. distribute-neg-out18.8%

        \[\leadsto \frac{\color{blue}{-\left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      3. neg-mul-118.8%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      4. times-frac18.8%

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a}} \]
      5. metadata-eval18.8%

        \[\leadsto \color{blue}{-0.5} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a} \]
      6. sub-neg18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{b \cdot b + \left(-4 \cdot \left(a \cdot c\right)\right)}}}{a} \]
      7. +-commutative18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(-4 \cdot \left(a \cdot c\right)\right) + b \cdot b}}}{a} \]
      8. distribute-rgt-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{4 \cdot \left(-a \cdot c\right)} + b \cdot b}}{a} \]
      9. distribute-rgt-neg-out18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{4 \cdot \color{blue}{\left(a \cdot \left(-c\right)\right)} + b \cdot b}}{a} \]
      10. *-commutative18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(a \cdot \left(-c\right)\right) \cdot 4} + b \cdot b}}{a} \]
      11. associate-*l*18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{a \cdot \left(\left(-c\right) \cdot 4\right)} + b \cdot b}}{a} \]
      12. fma-def18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\mathsf{fma}\left(a, \left(-c\right) \cdot 4, b \cdot b\right)}}}{a} \]
      13. distribute-lft-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{-c \cdot 4}, b \cdot b\right)}}{a} \]
      14. distribute-rgt-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{c \cdot \left(-4\right)}, b \cdot b\right)}}{a} \]
      15. metadata-eval18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot \color{blue}{-4}, b \cdot b\right)}}{a} \]
    3. Simplified18.8%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}{a}} \]
    4. Step-by-step derivation
      1. clear-num18.8%

        \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}}} \]
      2. inv-pow18.8%

        \[\leadsto -0.5 \cdot \color{blue}{{\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}\right)}^{-1}} \]
      3. pow218.8%

        \[\leadsto -0.5 \cdot {\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, \color{blue}{{b}^{2}}\right)}}\right)}^{-1} \]
    5. Applied egg-rr18.8%

      \[\leadsto -0.5 \cdot \color{blue}{{\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}\right)}^{-1}} \]
    6. Step-by-step derivation
      1. unpow-118.8%

        \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}}} \]
    7. Simplified18.8%

      \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}}} \]
    8. Taylor expanded in b around -inf 88.6%

      \[\leadsto -0.5 \cdot \frac{1}{\color{blue}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}} \]

    if -3.00000000000000017e-47 < b < 5.5000000000000002e96

    1. Initial program 83.4%

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

    if 5.5000000000000002e96 < b

    1. Initial program 54.2%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
      2. sqr-neg54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
      3. *-commutative54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
      4. sqr-neg54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
      6. *-commutative54.2%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified54.2%

      \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around inf 97.1%

      \[\leadsto \color{blue}{-1 \cdot \frac{b}{a}} \]
    5. Step-by-step derivation
      1. associate-*r/97.1%

        \[\leadsto \color{blue}{\frac{-1 \cdot b}{a}} \]
      2. mul-1-neg97.1%

        \[\leadsto \frac{\color{blue}{-b}}{a} \]
    6. Simplified97.1%

      \[\leadsto \color{blue}{\frac{-b}{a}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -3 \cdot 10^{-47}:\\ \;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\ \mathbf{elif}\;b \leq 5.5 \cdot 10^{+96}:\\ \;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-b}{a}\\ \end{array} \]

Alternative 3: 81.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.06 \cdot 10^{-48}:\\ \;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\ \mathbf{elif}\;b \leq 2.05 \cdot 10^{-38}:\\ \;\;\;\;-0.5 \cdot \frac{b + \sqrt{\left(a \cdot c\right) \cdot -4}}{a}\\ \mathbf{else}:\\ \;\;\;\;\frac{c}{b} - \frac{b}{a}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= b -1.06e-48)
   (* -0.5 (/ 1.0 (+ (* -0.5 (/ a b)) (* 0.5 (/ b c)))))
   (if (<= b 2.05e-38)
     (* -0.5 (/ (+ b (sqrt (* (* a c) -4.0))) a))
     (- (/ c b) (/ b a)))))
double code(double a, double b, double c) {
	double tmp;
	if (b <= -1.06e-48) {
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	} else if (b <= 2.05e-38) {
		tmp = -0.5 * ((b + sqrt(((a * c) * -4.0))) / a);
	} else {
		tmp = (c / b) - (b / 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) :: tmp
    if (b <= (-1.06d-48)) then
        tmp = (-0.5d0) * (1.0d0 / (((-0.5d0) * (a / b)) + (0.5d0 * (b / c))))
    else if (b <= 2.05d-38) then
        tmp = (-0.5d0) * ((b + sqrt(((a * c) * (-4.0d0)))) / a)
    else
        tmp = (c / b) - (b / a)
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double tmp;
	if (b <= -1.06e-48) {
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	} else if (b <= 2.05e-38) {
		tmp = -0.5 * ((b + Math.sqrt(((a * c) * -4.0))) / a);
	} else {
		tmp = (c / b) - (b / a);
	}
	return tmp;
}
def code(a, b, c):
	tmp = 0
	if b <= -1.06e-48:
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))))
	elif b <= 2.05e-38:
		tmp = -0.5 * ((b + math.sqrt(((a * c) * -4.0))) / a)
	else:
		tmp = (c / b) - (b / a)
	return tmp
function code(a, b, c)
	tmp = 0.0
	if (b <= -1.06e-48)
		tmp = Float64(-0.5 * Float64(1.0 / Float64(Float64(-0.5 * Float64(a / b)) + Float64(0.5 * Float64(b / c)))));
	elseif (b <= 2.05e-38)
		tmp = Float64(-0.5 * Float64(Float64(b + sqrt(Float64(Float64(a * c) * -4.0))) / a));
	else
		tmp = Float64(Float64(c / b) - Float64(b / a));
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	tmp = 0.0;
	if (b <= -1.06e-48)
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	elseif (b <= 2.05e-38)
		tmp = -0.5 * ((b + sqrt(((a * c) * -4.0))) / a);
	else
		tmp = (c / b) - (b / a);
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := If[LessEqual[b, -1.06e-48], N[(-0.5 * N[(1.0 / N[(N[(-0.5 * N[(a / b), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2.05e-38], N[(-0.5 * N[(N[(b + N[Sqrt[N[(N[(a * c), $MachinePrecision] * -4.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.06 \cdot 10^{-48}:\\
\;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\

\mathbf{elif}\;b \leq 2.05 \cdot 10^{-38}:\\
\;\;\;\;-0.5 \cdot \frac{b + \sqrt{\left(a \cdot c\right) \cdot -4}}{a}\\

\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b < -1.0600000000000001e-48

    1. Initial program 18.8%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. sub-neg18.8%

        \[\leadsto \frac{\color{blue}{\left(-b\right) + \left(-\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      2. distribute-neg-out18.8%

        \[\leadsto \frac{\color{blue}{-\left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      3. neg-mul-118.8%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      4. times-frac18.8%

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a}} \]
      5. metadata-eval18.8%

        \[\leadsto \color{blue}{-0.5} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a} \]
      6. sub-neg18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{b \cdot b + \left(-4 \cdot \left(a \cdot c\right)\right)}}}{a} \]
      7. +-commutative18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(-4 \cdot \left(a \cdot c\right)\right) + b \cdot b}}}{a} \]
      8. distribute-rgt-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{4 \cdot \left(-a \cdot c\right)} + b \cdot b}}{a} \]
      9. distribute-rgt-neg-out18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{4 \cdot \color{blue}{\left(a \cdot \left(-c\right)\right)} + b \cdot b}}{a} \]
      10. *-commutative18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(a \cdot \left(-c\right)\right) \cdot 4} + b \cdot b}}{a} \]
      11. associate-*l*18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{a \cdot \left(\left(-c\right) \cdot 4\right)} + b \cdot b}}{a} \]
      12. fma-def18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\mathsf{fma}\left(a, \left(-c\right) \cdot 4, b \cdot b\right)}}}{a} \]
      13. distribute-lft-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{-c \cdot 4}, b \cdot b\right)}}{a} \]
      14. distribute-rgt-neg-in18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{c \cdot \left(-4\right)}, b \cdot b\right)}}{a} \]
      15. metadata-eval18.8%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot \color{blue}{-4}, b \cdot b\right)}}{a} \]
    3. Simplified18.8%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}{a}} \]
    4. Step-by-step derivation
      1. clear-num18.8%

        \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}}} \]
      2. inv-pow18.8%

        \[\leadsto -0.5 \cdot \color{blue}{{\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}\right)}^{-1}} \]
      3. pow218.8%

        \[\leadsto -0.5 \cdot {\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, \color{blue}{{b}^{2}}\right)}}\right)}^{-1} \]
    5. Applied egg-rr18.8%

      \[\leadsto -0.5 \cdot \color{blue}{{\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}\right)}^{-1}} \]
    6. Step-by-step derivation
      1. unpow-118.8%

        \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}}} \]
    7. Simplified18.8%

      \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}}} \]
    8. Taylor expanded in b around -inf 88.6%

      \[\leadsto -0.5 \cdot \frac{1}{\color{blue}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}} \]

    if -1.0600000000000001e-48 < b < 2.0499999999999999e-38

    1. Initial program 80.9%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. sub-neg80.9%

        \[\leadsto \frac{\color{blue}{\left(-b\right) + \left(-\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      2. distribute-neg-out80.9%

        \[\leadsto \frac{\color{blue}{-\left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      3. neg-mul-180.9%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      4. times-frac80.9%

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a}} \]
      5. metadata-eval80.9%

        \[\leadsto \color{blue}{-0.5} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a} \]
      6. sub-neg80.9%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{b \cdot b + \left(-4 \cdot \left(a \cdot c\right)\right)}}}{a} \]
      7. +-commutative80.9%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(-4 \cdot \left(a \cdot c\right)\right) + b \cdot b}}}{a} \]
      8. distribute-rgt-neg-in80.9%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{4 \cdot \left(-a \cdot c\right)} + b \cdot b}}{a} \]
      9. distribute-rgt-neg-out80.9%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{4 \cdot \color{blue}{\left(a \cdot \left(-c\right)\right)} + b \cdot b}}{a} \]
      10. *-commutative80.9%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(a \cdot \left(-c\right)\right) \cdot 4} + b \cdot b}}{a} \]
      11. associate-*l*79.6%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{a \cdot \left(\left(-c\right) \cdot 4\right)} + b \cdot b}}{a} \]
      12. fma-def79.6%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\mathsf{fma}\left(a, \left(-c\right) \cdot 4, b \cdot b\right)}}}{a} \]
      13. distribute-lft-neg-in79.6%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{-c \cdot 4}, b \cdot b\right)}}{a} \]
      14. distribute-rgt-neg-in79.6%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{c \cdot \left(-4\right)}, b \cdot b\right)}}{a} \]
      15. metadata-eval79.6%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot \color{blue}{-4}, b \cdot b\right)}}{a} \]
    3. Simplified79.6%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}{a}} \]
    4. Taylor expanded in a around inf 73.4%

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

    if 2.0499999999999999e-38 < b

    1. Initial program 64.8%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative64.8%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
      2. sqr-neg64.8%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
      3. *-commutative64.8%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
      4. sqr-neg64.8%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*64.8%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
      6. *-commutative64.8%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified64.8%

      \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around inf 89.1%

      \[\leadsto \color{blue}{-1 \cdot \frac{b}{a} + \frac{c}{b}} \]
    5. Step-by-step derivation
      1. +-commutative89.1%

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

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

        \[\leadsto \color{blue}{\frac{c}{b} - \frac{b}{a}} \]
    6. Simplified89.1%

      \[\leadsto \color{blue}{\frac{c}{b} - \frac{b}{a}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification84.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.06 \cdot 10^{-48}:\\ \;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\ \mathbf{elif}\;b \leq 2.05 \cdot 10^{-38}:\\ \;\;\;\;-0.5 \cdot \frac{b + \sqrt{\left(a \cdot c\right) \cdot -4}}{a}\\ \mathbf{else}:\\ \;\;\;\;\frac{c}{b} - \frac{b}{a}\\ \end{array} \]

Alternative 4: 68.0% accurate, 6.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\ \;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\ \mathbf{else}:\\ \;\;\;\;\frac{c}{b} - \frac{b}{a}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= b -5e-310)
   (* -0.5 (/ 1.0 (+ (* -0.5 (/ a b)) (* 0.5 (/ b c)))))
   (- (/ c b) (/ b a))))
double code(double a, double b, double c) {
	double tmp;
	if (b <= -5e-310) {
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	} else {
		tmp = (c / b) - (b / 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) :: tmp
    if (b <= (-5d-310)) then
        tmp = (-0.5d0) * (1.0d0 / (((-0.5d0) * (a / b)) + (0.5d0 * (b / c))))
    else
        tmp = (c / b) - (b / a)
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double tmp;
	if (b <= -5e-310) {
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	} else {
		tmp = (c / b) - (b / a);
	}
	return tmp;
}
def code(a, b, c):
	tmp = 0
	if b <= -5e-310:
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))))
	else:
		tmp = (c / b) - (b / a)
	return tmp
function code(a, b, c)
	tmp = 0.0
	if (b <= -5e-310)
		tmp = Float64(-0.5 * Float64(1.0 / Float64(Float64(-0.5 * Float64(a / b)) + Float64(0.5 * Float64(b / c)))));
	else
		tmp = Float64(Float64(c / b) - Float64(b / a));
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	tmp = 0.0;
	if (b <= -5e-310)
		tmp = -0.5 * (1.0 / ((-0.5 * (a / b)) + (0.5 * (b / c))));
	else
		tmp = (c / b) - (b / a);
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := If[LessEqual[b, -5e-310], N[(-0.5 * N[(1.0 / N[(N[(-0.5 * N[(a / b), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\
\;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\

\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -4.999999999999985e-310

    1. Initial program 35.1%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. sub-neg35.1%

        \[\leadsto \frac{\color{blue}{\left(-b\right) + \left(-\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      2. distribute-neg-out35.1%

        \[\leadsto \frac{\color{blue}{-\left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      3. neg-mul-135.1%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\right)}}{2 \cdot a} \]
      4. times-frac35.1%

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a}} \]
      5. metadata-eval35.1%

        \[\leadsto \color{blue}{-0.5} \cdot \frac{b + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{a} \]
      6. sub-neg35.1%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{b \cdot b + \left(-4 \cdot \left(a \cdot c\right)\right)}}}{a} \]
      7. +-commutative35.1%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(-4 \cdot \left(a \cdot c\right)\right) + b \cdot b}}}{a} \]
      8. distribute-rgt-neg-in35.1%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{4 \cdot \left(-a \cdot c\right)} + b \cdot b}}{a} \]
      9. distribute-rgt-neg-out35.1%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{4 \cdot \color{blue}{\left(a \cdot \left(-c\right)\right)} + b \cdot b}}{a} \]
      10. *-commutative35.1%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\left(a \cdot \left(-c\right)\right) \cdot 4} + b \cdot b}}{a} \]
      11. associate-*l*35.1%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{a \cdot \left(\left(-c\right) \cdot 4\right)} + b \cdot b}}{a} \]
      12. fma-def35.2%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\color{blue}{\mathsf{fma}\left(a, \left(-c\right) \cdot 4, b \cdot b\right)}}}{a} \]
      13. distribute-lft-neg-in35.2%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{-c \cdot 4}, b \cdot b\right)}}{a} \]
      14. distribute-rgt-neg-in35.2%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, \color{blue}{c \cdot \left(-4\right)}, b \cdot b\right)}}{a} \]
      15. metadata-eval35.2%

        \[\leadsto -0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot \color{blue}{-4}, b \cdot b\right)}}{a} \]
    3. Simplified35.2%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}{a}} \]
    4. Step-by-step derivation
      1. clear-num35.2%

        \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}}} \]
      2. inv-pow35.2%

        \[\leadsto -0.5 \cdot \color{blue}{{\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}\right)}^{-1}} \]
      3. pow235.2%

        \[\leadsto -0.5 \cdot {\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, \color{blue}{{b}^{2}}\right)}}\right)}^{-1} \]
    5. Applied egg-rr35.2%

      \[\leadsto -0.5 \cdot \color{blue}{{\left(\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}\right)}^{-1}} \]
    6. Step-by-step derivation
      1. unpow-135.2%

        \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}}} \]
    7. Simplified35.2%

      \[\leadsto -0.5 \cdot \color{blue}{\frac{1}{\frac{a}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, {b}^{2}\right)}}}} \]
    8. Taylor expanded in b around -inf 69.5%

      \[\leadsto -0.5 \cdot \frac{1}{\color{blue}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}} \]

    if -4.999999999999985e-310 < b

    1. Initial program 68.4%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
      2. sqr-neg68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
      3. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
      4. sqr-neg68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
      6. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified68.4%

      \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around inf 71.0%

      \[\leadsto \color{blue}{-1 \cdot \frac{b}{a} + \frac{c}{b}} \]
    5. Step-by-step derivation
      1. +-commutative71.0%

        \[\leadsto \color{blue}{\frac{c}{b} + -1 \cdot \frac{b}{a}} \]
      2. mul-1-neg71.0%

        \[\leadsto \frac{c}{b} + \color{blue}{\left(-\frac{b}{a}\right)} \]
      3. unsub-neg71.0%

        \[\leadsto \color{blue}{\frac{c}{b} - \frac{b}{a}} \]
    6. Simplified71.0%

      \[\leadsto \color{blue}{\frac{c}{b} - \frac{b}{a}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification70.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\ \;\;\;\;-0.5 \cdot \frac{1}{-0.5 \cdot \frac{a}{b} + 0.5 \cdot \frac{b}{c}}\\ \mathbf{else}:\\ \;\;\;\;\frac{c}{b} - \frac{b}{a}\\ \end{array} \]

Alternative 5: 68.3% accurate, 12.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\ \;\;\;\;-\frac{c}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{c}{b} - \frac{b}{a}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= b -5e-310) (- (/ c b)) (- (/ c b) (/ b a))))
double code(double a, double b, double c) {
	double tmp;
	if (b <= -5e-310) {
		tmp = -(c / b);
	} else {
		tmp = (c / b) - (b / 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) :: tmp
    if (b <= (-5d-310)) then
        tmp = -(c / b)
    else
        tmp = (c / b) - (b / a)
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double tmp;
	if (b <= -5e-310) {
		tmp = -(c / b);
	} else {
		tmp = (c / b) - (b / a);
	}
	return tmp;
}
def code(a, b, c):
	tmp = 0
	if b <= -5e-310:
		tmp = -(c / b)
	else:
		tmp = (c / b) - (b / a)
	return tmp
function code(a, b, c)
	tmp = 0.0
	if (b <= -5e-310)
		tmp = Float64(-Float64(c / b));
	else
		tmp = Float64(Float64(c / b) - Float64(b / a));
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	tmp = 0.0;
	if (b <= -5e-310)
		tmp = -(c / b);
	else
		tmp = (c / b) - (b / a);
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := If[LessEqual[b, -5e-310], (-N[(c / b), $MachinePrecision]), N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\
\;\;\;\;-\frac{c}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -4.999999999999985e-310

    1. Initial program 35.1%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
      2. sqr-neg35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
      3. *-commutative35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
      4. sqr-neg35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
      6. *-commutative35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified35.1%

      \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around -inf 69.5%

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
    5. Step-by-step derivation
      1. mul-1-neg69.5%

        \[\leadsto \color{blue}{-\frac{c}{b}} \]
    6. Simplified69.5%

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

    if -4.999999999999985e-310 < b

    1. Initial program 68.4%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
      2. sqr-neg68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
      3. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
      4. sqr-neg68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
      6. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified68.4%

      \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around inf 71.0%

      \[\leadsto \color{blue}{-1 \cdot \frac{b}{a} + \frac{c}{b}} \]
    5. Step-by-step derivation
      1. +-commutative71.0%

        \[\leadsto \color{blue}{\frac{c}{b} + -1 \cdot \frac{b}{a}} \]
      2. mul-1-neg71.0%

        \[\leadsto \frac{c}{b} + \color{blue}{\left(-\frac{b}{a}\right)} \]
      3. unsub-neg71.0%

        \[\leadsto \color{blue}{\frac{c}{b} - \frac{b}{a}} \]
    6. Simplified71.0%

      \[\leadsto \color{blue}{\frac{c}{b} - \frac{b}{a}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification70.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\ \;\;\;\;-\frac{c}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{c}{b} - \frac{b}{a}\\ \end{array} \]

Alternative 6: 68.1% accurate, 19.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\ \;\;\;\;-\frac{c}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{-b}{a}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= b -5e-310) (- (/ c b)) (/ (- b) a)))
double code(double a, double b, double c) {
	double tmp;
	if (b <= -5e-310) {
		tmp = -(c / b);
	} else {
		tmp = -b / 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) :: tmp
    if (b <= (-5d-310)) then
        tmp = -(c / b)
    else
        tmp = -b / a
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double tmp;
	if (b <= -5e-310) {
		tmp = -(c / b);
	} else {
		tmp = -b / a;
	}
	return tmp;
}
def code(a, b, c):
	tmp = 0
	if b <= -5e-310:
		tmp = -(c / b)
	else:
		tmp = -b / a
	return tmp
function code(a, b, c)
	tmp = 0.0
	if (b <= -5e-310)
		tmp = Float64(-Float64(c / b));
	else
		tmp = Float64(Float64(-b) / a);
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	tmp = 0.0;
	if (b <= -5e-310)
		tmp = -(c / b);
	else
		tmp = -b / a;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := If[LessEqual[b, -5e-310], (-N[(c / b), $MachinePrecision]), N[((-b) / a), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\
\;\;\;\;-\frac{c}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -4.999999999999985e-310

    1. Initial program 35.1%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
      2. sqr-neg35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
      3. *-commutative35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
      4. sqr-neg35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
      6. *-commutative35.1%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified35.1%

      \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around -inf 69.5%

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
    5. Step-by-step derivation
      1. mul-1-neg69.5%

        \[\leadsto \color{blue}{-\frac{c}{b}} \]
    6. Simplified69.5%

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

    if -4.999999999999985e-310 < b

    1. Initial program 68.4%

      \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
      2. sqr-neg68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
      3. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
      4. sqr-neg68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
      5. associate-*r*68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
      6. *-commutative68.4%

        \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified68.4%

      \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around inf 70.5%

      \[\leadsto \color{blue}{-1 \cdot \frac{b}{a}} \]
    5. Step-by-step derivation
      1. associate-*r/70.5%

        \[\leadsto \color{blue}{\frac{-1 \cdot b}{a}} \]
      2. mul-1-neg70.5%

        \[\leadsto \frac{\color{blue}{-b}}{a} \]
    6. Simplified70.5%

      \[\leadsto \color{blue}{\frac{-b}{a}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification70.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\ \;\;\;\;-\frac{c}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{-b}{a}\\ \end{array} \]

Alternative 7: 35.5% 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 52.0%

    \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
    2. sqr-neg52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
    3. *-commutative52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
    4. sqr-neg52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    5. associate-*r*52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
    6. *-commutative52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified52.0%

    \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Taylor expanded in b around -inf 35.5%

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
  5. Step-by-step derivation
    1. mul-1-neg35.5%

      \[\leadsto \color{blue}{-\frac{c}{b}} \]
  6. Simplified35.5%

    \[\leadsto \color{blue}{-\frac{c}{b}} \]
  7. Final simplification35.5%

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

Alternative 8: 11.1% accurate, 38.7× 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(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 52.0%

    \[\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \color{blue}{\left(c \cdot a\right)}}}{2 \cdot a} \]
    2. sqr-neg52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{\left(-b\right) \cdot \left(-b\right)} - 4 \cdot \left(c \cdot a\right)}}{2 \cdot a} \]
    3. *-commutative52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{\left(-b\right) \cdot \left(-b\right) - 4 \cdot \color{blue}{\left(a \cdot c\right)}}}{2 \cdot a} \]
    4. sqr-neg52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a} \]
    5. associate-*r*52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{2 \cdot a} \]
    6. *-commutative52.0%

      \[\leadsto \frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified52.0%

    \[\leadsto \color{blue}{\frac{\left(-b\right) - \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Taylor expanded in b around inf 37.2%

    \[\leadsto \color{blue}{-1 \cdot \frac{b}{a} + \frac{c}{b}} \]
  5. Step-by-step derivation
    1. +-commutative37.2%

      \[\leadsto \color{blue}{\frac{c}{b} + -1 \cdot \frac{b}{a}} \]
    2. mul-1-neg37.2%

      \[\leadsto \frac{c}{b} + \color{blue}{\left(-\frac{b}{a}\right)} \]
    3. unsub-neg37.2%

      \[\leadsto \color{blue}{\frac{c}{b} - \frac{b}{a}} \]
  6. Simplified37.2%

    \[\leadsto \color{blue}{\frac{c}{b} - \frac{b}{a}} \]
  7. Taylor expanded in c around inf 10.2%

    \[\leadsto \color{blue}{\frac{c}{b}} \]
  8. Final simplification10.2%

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

Developer target: 70.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\\ \mathbf{if}\;b < 0:\\ \;\;\;\;\frac{c}{a \cdot \frac{\left(-b\right) + t_0}{2 \cdot a}}\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(-b\right) - t_0}{2 \cdot a}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (sqrt (- (* b b) (* 4.0 (* a c))))))
   (if (< b 0.0)
     (/ c (* a (/ (+ (- b) t_0) (* 2.0 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 = c / (a * ((-b + t_0) / (2.0 * a)));
	} else {
		tmp = (-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 = c / (a * ((-b + t_0) / (2.0d0 * a)))
    else
        tmp = (-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 = c / (a * ((-b + t_0) / (2.0 * a)));
	} else {
		tmp = (-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 = c / (a * ((-b + t_0) / (2.0 * a)))
	else:
		tmp = (-b - t_0) / (2.0 * a)
	return tmp
function code(a, b, c)
	t_0 = sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(a * c))))
	tmp = 0.0
	if (b < 0.0)
		tmp = Float64(c / Float64(a * Float64(Float64(Float64(-b) + t_0) / Float64(2.0 * a))));
	else
		tmp = 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 = c / (a * ((-b + t_0) / (2.0 * a)));
	else
		tmp = (-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[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[Less[b, 0.0], N[(c / N[(a * N[(N[((-b) + t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[((-b) - t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}\\
\mathbf{if}\;b < 0:\\
\;\;\;\;\frac{c}{a \cdot \frac{\left(-b\right) + t_0}{2 \cdot a}}\\

\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) - t_0}{2 \cdot a}\\


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2023322 
(FPCore (a b c)
  :name "The quadratic formula (r2)"
  :precision binary64

  :herbie-target
  (if (< b 0.0) (/ c (* a (/ (+ (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))) (/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))

  (/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))