Quadratic roots, narrow range

Percentage Accurate: 56.0% → 90.9%
Time: 4.5s
Alternatives: 6
Speedup: 4.6×

Specification

?
\[\left(\left(1.0536712127723509 \cdot 10^{-8} < a \land a < 94906265.62425156\right) \land \left(1.0536712127723509 \cdot 10^{-8} < b \land b < 94906265.62425156\right)\right) \land \left(1.0536712127723509 \cdot 10^{-8} < c \land c < 94906265.62425156\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(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);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(a, b, c)
use fmin_fmax_functions
    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}

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 6 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: 56.0% 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);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(a, b, c)
use fmin_fmax_functions
    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: 90.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{b \cdot b}, -5, -2 \cdot a\right)}{b \cdot b} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \end{array} \]
(FPCore (a b c)
 :precision binary64
 (fma
  a
  (/
   (*
    (- (* (/ (fma (* (* a a) (/ c (* b b))) -5.0 (* -2.0 a)) (* b b)) c) 1.0)
    (* c c))
   (* (* b b) b))
  (/ (- c) b)))
double code(double a, double b, double c) {
	return fma(a, (((((fma(((a * a) * (c / (b * b))), -5.0, (-2.0 * a)) / (b * b)) * c) - 1.0) * (c * c)) / ((b * b) * b)), (-c / b));
}
function code(a, b, c)
	return fma(a, Float64(Float64(Float64(Float64(Float64(fma(Float64(Float64(a * a) * Float64(c / Float64(b * b))), -5.0, Float64(-2.0 * a)) / Float64(b * b)) * c) - 1.0) * Float64(c * c)) / Float64(Float64(b * b) * b)), Float64(Float64(-c) / b))
end
code[a_, b_, c_] := N[(a * N[(N[(N[(N[(N[(N[(N[(N[(a * a), $MachinePrecision] * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -5.0 + N[(-2.0 * a), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision] - 1.0), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * b), $MachinePrecision]), $MachinePrecision] + N[((-c) / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{b \cdot b}, -5, -2 \cdot a\right)}{b \cdot b} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right)
\end{array}
Derivation
  1. Initial program 56.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Taylor expanded in a around 0

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + a \cdot \left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)} \]
  3. Applied rewrites90.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(\frac{\left(\frac{\left(c \cdot c\right) \cdot \left(c \cdot c\right)}{\left(\left(b \cdot b\right) \cdot b\right) \cdot \left(\left(b \cdot b\right) \cdot b\right)} \cdot 20\right) \cdot a}{b}, -0.25, \frac{\left(c \cdot c\right) \cdot c}{{b}^{5}} \cdot -2\right), -\frac{c \cdot c}{\left(b \cdot b\right) \cdot b}\right), \frac{-c}{b}\right)} \]
  4. Taylor expanded in b around inf

    \[\leadsto \mathsf{fma}\left(a, \frac{\left(-5 \cdot \frac{{a}^{2} \cdot {c}^{4}}{{b}^{4}} + -2 \cdot \frac{a \cdot {c}^{3}}{{b}^{2}}\right) - {c}^{2}}{\color{blue}{{b}^{3}}}, \frac{-c}{b}\right) \]
  5. Applied rewrites90.9%

    \[\leadsto \mathsf{fma}\left(a, \frac{\mathsf{fma}\left(\frac{\left(a \cdot a\right) \cdot \left(\left(\left(c \cdot c\right) \cdot c\right) \cdot c\right)}{\left(b \cdot b\right) \cdot \left(b \cdot b\right)}, -5, \frac{\left(\left(c \cdot c\right) \cdot c\right) \cdot a}{b \cdot b} \cdot -2 - c \cdot c\right)}{\color{blue}{\left(b \cdot b\right) \cdot b}}, \frac{-c}{b}\right) \]
  6. Taylor expanded in c around 0

    \[\leadsto \mathsf{fma}\left(a, \frac{{c}^{2} \cdot \left(c \cdot \left(-5 \cdot \frac{{a}^{2} \cdot c}{{b}^{4}} + -2 \cdot \frac{a}{{b}^{2}}\right) - 1\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
  7. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(c \cdot \left(-5 \cdot \frac{{a}^{2} \cdot c}{{b}^{4}} + -2 \cdot \frac{a}{{b}^{2}}\right) - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    2. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(c \cdot \left(-5 \cdot \frac{{a}^{2} \cdot c}{{b}^{4}} + -2 \cdot \frac{a}{{b}^{2}}\right) - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
  8. Applied rewrites90.9%

    \[\leadsto \mathsf{fma}\left(a, \frac{\left(\mathsf{fma}\left(\frac{\left(a \cdot a\right) \cdot c}{\left(b \cdot b\right) \cdot \left(b \cdot b\right)}, -5, \frac{a}{b \cdot b} \cdot -2\right) \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
  9. Taylor expanded in b around inf

    \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{-5 \cdot \frac{{a}^{2} \cdot c}{{b}^{2}} + -2 \cdot a}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
  10. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{-5 \cdot \frac{{a}^{2} \cdot c}{{b}^{2}} + -2 \cdot a}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\frac{{a}^{2} \cdot c}{{b}^{2}} \cdot -5 + -2 \cdot a}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    3. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\frac{{a}^{2} \cdot c}{{b}^{2}}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    4. associate-/l*N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left({a}^{2} \cdot \frac{c}{{b}^{2}}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    5. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left({a}^{2} \cdot \frac{c}{{b}^{2}}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    6. pow2N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{{b}^{2}}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    7. lift-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{{b}^{2}}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    8. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{{b}^{2}}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    9. pow2N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{b \cdot b}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    10. lift-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{b \cdot b}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    11. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{b \cdot b}, -5, -2 \cdot a\right)}{{b}^{2}} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    12. pow2N/A

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{b \cdot b}, -5, -2 \cdot a\right)}{b \cdot b} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    13. lift-*.f6490.9

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{b \cdot b}, -5, -2 \cdot a\right)}{b \cdot b} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
  11. Applied rewrites90.9%

    \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot \frac{c}{b \cdot b}, -5, -2 \cdot a\right)}{b \cdot b} \cdot c - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
  12. Add Preprocessing

Alternative 2: 89.6% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \leq -5:\\ \;\;\;\;\frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \left(c \cdot a\right)\right)}}{a + a}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{b \cdot b}\right) \cdot -2 - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right)\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)) -5.0)
   (/ (+ (- b) (sqrt (fma b b (* -4.0 (* c a))))) (+ a a))
   (fma
    a
    (/ (* (- (* (* a (/ c (* b b))) -2.0) 1.0) (* c c)) (* (* b b) b))
    (/ (- c) b))))
double code(double a, double b, double c) {
	double tmp;
	if (((-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)) <= -5.0) {
		tmp = (-b + sqrt(fma(b, b, (-4.0 * (c * a))))) / (a + a);
	} else {
		tmp = fma(a, (((((a * (c / (b * b))) * -2.0) - 1.0) * (c * c)) / ((b * b) * b)), (-c / b));
	}
	return tmp;
}
function code(a, b, c)
	tmp = 0.0
	if (Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) <= -5.0)
		tmp = Float64(Float64(Float64(-b) + sqrt(fma(b, b, Float64(-4.0 * Float64(c * a))))) / Float64(a + a));
	else
		tmp = fma(a, Float64(Float64(Float64(Float64(Float64(a * Float64(c / Float64(b * b))) * -2.0) - 1.0) * Float64(c * c)) / Float64(Float64(b * b) * b)), Float64(Float64(-c) / b));
	end
	return tmp
end
code[a_, b_, c_] := If[LessEqual[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], -5.0], N[(N[((-b) + N[Sqrt[N[(b * b + N[(-4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a + a), $MachinePrecision]), $MachinePrecision], N[(a * N[(N[(N[(N[(N[(a * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision] - 1.0), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * b), $MachinePrecision]), $MachinePrecision] + N[((-c) / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \leq -5:\\
\;\;\;\;\frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \left(c \cdot a\right)\right)}}{a + a}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{b \cdot b}\right) \cdot -2 - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\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 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a)) < -5

    1. Initial program 83.4%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{b \cdot b} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      2. pow2N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      3. pow-to-expN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      4. lower-exp.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      6. lower-log.f6480.1

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b} \cdot 2} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    3. Applied rewrites80.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    4. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{2 \cdot a}} \]
      2. count-2-revN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
      3. lower-+.f6480.1

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
    5. Applied rewrites80.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
    6. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}}{a + a} \]
      2. lift-exp.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      4. lift-log.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b} \cdot 2} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      5. pow-to-expN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      6. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{a + a} \]
      7. lift-*.f64N/A

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

        \[\leadsto \frac{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}{a + a} \]
      9. fp-cancel-sub-sign-invN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2} + \left(\mathsf{neg}\left(4\right)\right) \cdot \left(a \cdot c\right)}}}{a + a} \]
      10. pow2N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{b \cdot b} + \left(\mathsf{neg}\left(4\right)\right) \cdot \left(a \cdot c\right)}}{a + a} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b + \color{blue}{-4} \cdot \left(a \cdot c\right)}}{a + a} \]
      12. lower-fma.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(b, b, -4 \cdot \left(a \cdot c\right)\right)}}}{a + a} \]
      13. lower-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, \color{blue}{-4 \cdot \left(a \cdot c\right)}\right)}}{a + a} \]
      14. *-commutativeN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \color{blue}{\left(c \cdot a\right)}\right)}}{a + a} \]
      15. lower-*.f6483.6

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \color{blue}{\left(c \cdot a\right)}\right)}}{a + a} \]
    7. Applied rewrites83.6%

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

    if -5 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a))

    1. Initial program 52.2%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Taylor expanded in a around 0

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + a \cdot \left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)} \]
    3. Applied rewrites93.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(\frac{\left(\frac{\left(c \cdot c\right) \cdot \left(c \cdot c\right)}{\left(\left(b \cdot b\right) \cdot b\right) \cdot \left(\left(b \cdot b\right) \cdot b\right)} \cdot 20\right) \cdot a}{b}, -0.25, \frac{\left(c \cdot c\right) \cdot c}{{b}^{5}} \cdot -2\right), -\frac{c \cdot c}{\left(b \cdot b\right) \cdot b}\right), \frac{-c}{b}\right)} \]
    4. Taylor expanded in b around inf

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(-5 \cdot \frac{{a}^{2} \cdot {c}^{4}}{{b}^{4}} + -2 \cdot \frac{a \cdot {c}^{3}}{{b}^{2}}\right) - {c}^{2}}{\color{blue}{{b}^{3}}}, \frac{-c}{b}\right) \]
    5. Applied rewrites93.1%

      \[\leadsto \mathsf{fma}\left(a, \frac{\mathsf{fma}\left(\frac{\left(a \cdot a\right) \cdot \left(\left(\left(c \cdot c\right) \cdot c\right) \cdot c\right)}{\left(b \cdot b\right) \cdot \left(b \cdot b\right)}, -5, \frac{\left(\left(c \cdot c\right) \cdot c\right) \cdot a}{b \cdot b} \cdot -2 - c \cdot c\right)}{\color{blue}{\left(b \cdot b\right) \cdot b}}, \frac{-c}{b}\right) \]
    6. Taylor expanded in c around 0

      \[\leadsto \mathsf{fma}\left(a, \frac{{c}^{2} \cdot \left(-2 \cdot \frac{a \cdot c}{{b}^{2}} - 1\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(-2 \cdot \frac{a \cdot c}{{b}^{2}} - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      2. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(-2 \cdot \frac{a \cdot c}{{b}^{2}} - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      3. lower--.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(-2 \cdot \frac{a \cdot c}{{b}^{2}} - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      4. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{a \cdot c}{{b}^{2}} \cdot -2 - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      5. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\frac{a \cdot c}{{b}^{2}} \cdot -2 - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      6. associate-/l*N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{{b}^{2}}\right) \cdot -2 - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      7. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{{b}^{2}}\right) \cdot -2 - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      8. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{{b}^{2}}\right) \cdot -2 - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      9. pow2N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{b \cdot b}\right) \cdot -2 - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      10. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{b \cdot b}\right) \cdot -2 - 1\right) \cdot {c}^{2}}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      11. pow2N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{b \cdot b}\right) \cdot -2 - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      12. lift-*.f6490.5

        \[\leadsto \mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{b \cdot b}\right) \cdot -2 - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    8. Applied rewrites90.5%

      \[\leadsto \mathsf{fma}\left(a, \frac{\left(\left(a \cdot \frac{c}{b \cdot b}\right) \cdot -2 - 1\right) \cdot \left(c \cdot c\right)}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 85.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \leq -0.003:\\ \;\;\;\;\frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \left(c \cdot a\right)\right)}}{a + a}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a, \frac{-c \cdot c}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right)\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)) -0.003)
   (/ (+ (- b) (sqrt (fma b b (* -4.0 (* c a))))) (+ a a))
   (fma a (/ (- (* c c)) (* (* b b) b)) (/ (- c) b))))
double code(double a, double b, double c) {
	double tmp;
	if (((-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)) <= -0.003) {
		tmp = (-b + sqrt(fma(b, b, (-4.0 * (c * a))))) / (a + a);
	} else {
		tmp = fma(a, (-(c * c) / ((b * b) * b)), (-c / b));
	}
	return tmp;
}
function code(a, b, c)
	tmp = 0.0
	if (Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) <= -0.003)
		tmp = Float64(Float64(Float64(-b) + sqrt(fma(b, b, Float64(-4.0 * Float64(c * a))))) / Float64(a + a));
	else
		tmp = fma(a, Float64(Float64(-Float64(c * c)) / Float64(Float64(b * b) * b)), Float64(Float64(-c) / b));
	end
	return tmp
end
code[a_, b_, c_] := If[LessEqual[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], -0.003], N[(N[((-b) + N[Sqrt[N[(b * b + N[(-4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a + a), $MachinePrecision]), $MachinePrecision], N[(a * N[((-N[(c * c), $MachinePrecision]) / N[(N[(b * b), $MachinePrecision] * b), $MachinePrecision]), $MachinePrecision] + N[((-c) / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \leq -0.003:\\
\;\;\;\;\frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \left(c \cdot a\right)\right)}}{a + a}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(a, \frac{-c \cdot c}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\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 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a)) < -0.0030000000000000001

    1. Initial program 77.1%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{b \cdot b} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      2. pow2N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      3. pow-to-expN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      4. lower-exp.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      6. lower-log.f6473.1

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b} \cdot 2} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    3. Applied rewrites73.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    4. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{2 \cdot a}} \]
      2. count-2-revN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
      3. lower-+.f6473.1

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
    5. Applied rewrites73.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
    6. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}}{a + a} \]
      2. lift-exp.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      4. lift-log.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b} \cdot 2} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      5. pow-to-expN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      6. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{a + a} \]
      7. lift-*.f64N/A

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

        \[\leadsto \frac{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}{a + a} \]
      9. fp-cancel-sub-sign-invN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2} + \left(\mathsf{neg}\left(4\right)\right) \cdot \left(a \cdot c\right)}}}{a + a} \]
      10. pow2N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{b \cdot b} + \left(\mathsf{neg}\left(4\right)\right) \cdot \left(a \cdot c\right)}}{a + a} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b + \color{blue}{-4} \cdot \left(a \cdot c\right)}}{a + a} \]
      12. lower-fma.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(b, b, -4 \cdot \left(a \cdot c\right)\right)}}}{a + a} \]
      13. lower-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, \color{blue}{-4 \cdot \left(a \cdot c\right)}\right)}}{a + a} \]
      14. *-commutativeN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \color{blue}{\left(c \cdot a\right)}\right)}}{a + a} \]
      15. lower-*.f6477.2

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \color{blue}{\left(c \cdot a\right)}\right)}}{a + a} \]
    7. Applied rewrites77.2%

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

    if -0.0030000000000000001 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a))

    1. Initial program 45.4%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Taylor expanded in a around 0

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + a \cdot \left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)} \]
    3. Applied rewrites95.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(\frac{\left(\frac{\left(c \cdot c\right) \cdot \left(c \cdot c\right)}{\left(\left(b \cdot b\right) \cdot b\right) \cdot \left(\left(b \cdot b\right) \cdot b\right)} \cdot 20\right) \cdot a}{b}, -0.25, \frac{\left(c \cdot c\right) \cdot c}{{b}^{5}} \cdot -2\right), -\frac{c \cdot c}{\left(b \cdot b\right) \cdot b}\right), \frac{-c}{b}\right)} \]
    4. Taylor expanded in a around 0

      \[\leadsto \mathsf{fma}\left(a, -1 \cdot \color{blue}{\frac{{c}^{2}}{{b}^{3}}}, \frac{-c}{b}\right) \]
    5. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \mathsf{fma}\left(a, \frac{-1 \cdot {c}^{2}}{{b}^{\color{blue}{3}}}, \frac{-c}{b}\right) \]
      3. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(a, \frac{\mathsf{neg}\left({c}^{2}\right)}{{b}^{3}}, \frac{-c}{b}\right) \]
      4. lower-neg.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{-{c}^{2}}{{b}^{3}}, \frac{-c}{b}\right) \]
      5. pow2N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{-c \cdot c}{{b}^{3}}, \frac{-c}{b}\right) \]
      6. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{-c \cdot c}{{b}^{3}}, \frac{-c}{b}\right) \]
      7. pow3N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{-c \cdot c}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      8. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(a, \frac{-c \cdot c}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
      9. lift-*.f6489.2

        \[\leadsto \mathsf{fma}\left(a, \frac{-c \cdot c}{\left(b \cdot b\right) \cdot b}, \frac{-c}{b}\right) \]
    6. Applied rewrites89.2%

      \[\leadsto \mathsf{fma}\left(a, \frac{-c \cdot c}{\color{blue}{\left(b \cdot b\right) \cdot b}}, \frac{-c}{b}\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 85.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \leq -0.003:\\ \;\;\;\;\frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \left(c \cdot a\right)\right)}}{a + a}\\ \mathbf{else}:\\ \;\;\;\;-\frac{\mathsf{fma}\left(a, \frac{c \cdot c}{b \cdot b}, c\right)}{b}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)) -0.003)
   (/ (+ (- b) (sqrt (fma b b (* -4.0 (* c a))))) (+ a a))
   (- (/ (fma a (/ (* c c) (* b b)) c) b))))
double code(double a, double b, double c) {
	double tmp;
	if (((-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)) <= -0.003) {
		tmp = (-b + sqrt(fma(b, b, (-4.0 * (c * a))))) / (a + a);
	} else {
		tmp = -(fma(a, ((c * c) / (b * b)), c) / b);
	}
	return tmp;
}
function code(a, b, c)
	tmp = 0.0
	if (Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) <= -0.003)
		tmp = Float64(Float64(Float64(-b) + sqrt(fma(b, b, Float64(-4.0 * Float64(c * a))))) / Float64(a + a));
	else
		tmp = Float64(-Float64(fma(a, Float64(Float64(c * c) / Float64(b * b)), c) / b));
	end
	return tmp
end
code[a_, b_, c_] := If[LessEqual[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], -0.003], N[(N[((-b) + N[Sqrt[N[(b * b + N[(-4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a + a), $MachinePrecision]), $MachinePrecision], (-N[(N[(a * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision] / b), $MachinePrecision])]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \leq -0.003:\\
\;\;\;\;\frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \left(c \cdot a\right)\right)}}{a + a}\\

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


\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 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a)) < -0.0030000000000000001

    1. Initial program 77.1%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{b \cdot b} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      2. pow2N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      3. pow-to-expN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      4. lower-exp.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      6. lower-log.f6473.1

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b} \cdot 2} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    3. Applied rewrites73.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    4. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{2 \cdot a}} \]
      2. count-2-revN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
      3. lower-+.f6473.1

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
    5. Applied rewrites73.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a + a}} \]
    6. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2} - \left(4 \cdot a\right) \cdot c}}}{a + a} \]
      2. lift-exp.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{e^{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b \cdot 2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      4. lift-log.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{e^{\color{blue}{\log b} \cdot 2} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      5. pow-to-expN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(4 \cdot a\right) \cdot c}}{a + a} \]
      6. lift-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}}}{a + a} \]
      7. lift-*.f64N/A

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

        \[\leadsto \frac{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}{a + a} \]
      9. fp-cancel-sub-sign-invN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{{b}^{2} + \left(\mathsf{neg}\left(4\right)\right) \cdot \left(a \cdot c\right)}}}{a + a} \]
      10. pow2N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{b \cdot b} + \left(\mathsf{neg}\left(4\right)\right) \cdot \left(a \cdot c\right)}}{a + a} \]
      11. metadata-evalN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b + \color{blue}{-4} \cdot \left(a \cdot c\right)}}{a + a} \]
      12. lower-fma.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(b, b, -4 \cdot \left(a \cdot c\right)\right)}}}{a + a} \]
      13. lower-*.f64N/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, \color{blue}{-4 \cdot \left(a \cdot c\right)}\right)}}{a + a} \]
      14. *-commutativeN/A

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \color{blue}{\left(c \cdot a\right)}\right)}}{a + a} \]
      15. lower-*.f6477.2

        \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(b, b, -4 \cdot \color{blue}{\left(c \cdot a\right)}\right)}}{a + a} \]
    7. Applied rewrites77.2%

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

    if -0.0030000000000000001 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 4 binary64) a) c)))) (*.f64 #s(literal 2 binary64) a))

    1. Initial program 45.4%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Taylor expanded in a around 0

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

        \[\leadsto -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + \color{blue}{-1 \cdot \frac{c}{b}} \]
      2. lower-+.f64N/A

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

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

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

        \[\leadsto \left(-\frac{a \cdot {c}^{2}}{{b}^{3}}\right) + -1 \cdot \frac{c}{b} \]
      6. *-commutativeN/A

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

        \[\leadsto \left(-\frac{{c}^{2} \cdot a}{{b}^{3}}\right) + -1 \cdot \frac{c}{b} \]
      8. unpow2N/A

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{{b}^{3}}\right) + -1 \cdot \frac{c}{b} \]
      9. lower-*.f64N/A

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{{b}^{3}}\right) + -1 \cdot \frac{c}{b} \]
      10. unpow3N/A

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + -1 \cdot \frac{c}{b} \]
      11. pow2N/A

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{{b}^{2} \cdot b}\right) + -1 \cdot \frac{c}{b} \]
      12. lower-*.f64N/A

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{{b}^{2} \cdot b}\right) + -1 \cdot \frac{c}{b} \]
      13. pow2N/A

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + -1 \cdot \frac{c}{b} \]
      14. lift-*.f64N/A

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + -1 \cdot \frac{c}{b} \]
      15. associate-*r/N/A

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

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

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + \frac{\mathsf{neg}\left(c\right)}{\color{blue}{b}} \]
      18. lower-neg.f6489.2

        \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + \frac{-c}{b} \]
    4. Applied rewrites89.2%

      \[\leadsto \color{blue}{\left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + \frac{-c}{b}} \]
    5. Applied rewrites89.2%

      \[\leadsto -\frac{\mathsf{fma}\left(a, \frac{c \cdot c}{b \cdot b}, c\right)}{b} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 81.3% accurate, 1.2× speedup?

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

\\
-\frac{\mathsf{fma}\left(a, \frac{c \cdot c}{b \cdot b}, c\right)}{b}
\end{array}
Derivation
  1. Initial program 56.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Taylor expanded in a around 0

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

      \[\leadsto -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + \color{blue}{-1 \cdot \frac{c}{b}} \]
    2. lower-+.f64N/A

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

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

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

      \[\leadsto \left(-\frac{a \cdot {c}^{2}}{{b}^{3}}\right) + -1 \cdot \frac{c}{b} \]
    6. *-commutativeN/A

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

      \[\leadsto \left(-\frac{{c}^{2} \cdot a}{{b}^{3}}\right) + -1 \cdot \frac{c}{b} \]
    8. unpow2N/A

      \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{{b}^{3}}\right) + -1 \cdot \frac{c}{b} \]
    9. lower-*.f64N/A

      \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{{b}^{3}}\right) + -1 \cdot \frac{c}{b} \]
    10. unpow3N/A

      \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + -1 \cdot \frac{c}{b} \]
    11. pow2N/A

      \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{{b}^{2} \cdot b}\right) + -1 \cdot \frac{c}{b} \]
    12. lower-*.f64N/A

      \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{{b}^{2} \cdot b}\right) + -1 \cdot \frac{c}{b} \]
    13. pow2N/A

      \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + -1 \cdot \frac{c}{b} \]
    14. lift-*.f64N/A

      \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + -1 \cdot \frac{c}{b} \]
    15. associate-*r/N/A

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

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

      \[\leadsto \left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + \frac{\mathsf{neg}\left(c\right)}{\color{blue}{b}} \]
    18. lower-neg.f6481.3

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

    \[\leadsto \color{blue}{\left(-\frac{\left(c \cdot c\right) \cdot a}{\left(b \cdot b\right) \cdot b}\right) + \frac{-c}{b}} \]
  5. Applied rewrites81.3%

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

Alternative 6: 63.9% accurate, 4.6× 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;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(a, b, c)
use fmin_fmax_functions
    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 56.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Taylor expanded in a around 0

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

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

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{b} \]
    3. lower-/.f64N/A

      \[\leadsto \frac{\mathsf{neg}\left(c\right)}{\color{blue}{b}} \]
    4. lower-neg.f6463.9

      \[\leadsto \frac{-c}{b} \]
  4. Applied rewrites63.9%

    \[\leadsto \color{blue}{\frac{-c}{b}} \]
  5. Add Preprocessing

Reproduce

?
herbie shell --seed 2025122 
(FPCore (a b c)
  :name "Quadratic roots, narrow range"
  :precision binary64
  :pre (and (and (and (< 1.0536712127723509e-8 a) (< a 94906265.62425156)) (and (< 1.0536712127723509e-8 b) (< b 94906265.62425156))) (and (< 1.0536712127723509e-8 c) (< c 94906265.62425156)))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))