Cubic critical, medium range

Percentage Accurate: 31.2% → 99.4%
Time: 5.8s
Alternatives: 8
Speedup: 3.3×

Specification

?
\[\left(\left(1.1102230246251565 \cdot 10^{-16} < a \land a < 9007199254740992\right) \land \left(1.1102230246251565 \cdot 10^{-16} < b \land b < 9007199254740992\right)\right) \land \left(1.1102230246251565 \cdot 10^{-16} < c \land c < 9007199254740992\right)\]
\[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
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) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}

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: 31.2% accurate, 1.0× speedup?

\[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
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) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}

Alternative 1: 99.4% accurate, 0.9× speedup?

\[\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c}{3} \]
(FPCore (a b c)
 :precision binary64
 (* (/ -3.0 (+ (sqrt (fma (* c -3.0) a (* b b))) b)) (/ c 3.0)))
double code(double a, double b, double c) {
	return (-3.0 / (sqrt(fma((c * -3.0), a, (b * b))) + b)) * (c / 3.0);
}
function code(a, b, c)
	return Float64(Float64(-3.0 / Float64(sqrt(fma(Float64(c * -3.0), a, Float64(b * b))) + b)) * Float64(c / 3.0))
end
code[a_, b_, c_] := N[(N[(-3.0 / N[(N[Sqrt[N[(N[(c * -3.0), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision] * N[(c / 3.0), $MachinePrecision]), $MachinePrecision]
\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c}{3}
Derivation
  1. Initial program 31.2%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Step-by-step derivation
    1. lift-+.f64N/A

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

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(-b\right)}}{3 \cdot a} \]
    3. add-flipN/A

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}{3 \cdot a} \]
    4. flip--N/A

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right) \cdot \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}}{3 \cdot a} \]
    5. lower-unsound-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right) \cdot \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}}{3 \cdot a} \]
  3. Applied rewrites32.2%

    \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right) - b \cdot b}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}}{3 \cdot a} \]
  4. Step-by-step derivation
    1. lift--.f64N/A

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

      \[\leadsto \frac{\frac{\color{blue}{\left(\left(c \cdot -3\right) \cdot a + b \cdot b\right)} - b \cdot b}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    3. associate--l+N/A

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

      \[\leadsto \frac{\frac{\color{blue}{\left(c \cdot -3\right)} \cdot a + \left(b \cdot b - b \cdot b\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    5. associate-*l*N/A

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

      \[\leadsto \frac{\frac{c \cdot \color{blue}{\left(-3 \cdot a\right)} + \left(b \cdot b - b \cdot b\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    7. *-commutativeN/A

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

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b - b \cdot b\right)}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    9. +-inverses99.4

      \[\leadsto \frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, \color{blue}{0}\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
  5. Applied rewrites99.4%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
  6. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{\color{blue}{3 \cdot a}} \]
    2. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a}} \]
    3. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}}{3 \cdot a} \]
    4. lift-fma.f64N/A

      \[\leadsto \frac{\frac{\color{blue}{\left(-3 \cdot a\right) \cdot c + 0}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    5. +-rgt-identityN/A

      \[\leadsto \frac{\frac{\color{blue}{\left(-3 \cdot a\right) \cdot c}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    6. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{\left(-3 \cdot a\right) \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-3 \cdot a\right)} \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)} \]
    8. associate-*l*N/A

      \[\leadsto \frac{\color{blue}{-3 \cdot \left(a \cdot c\right)}}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)} \]
    9. times-fracN/A

      \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{a \cdot c}{3 \cdot a}} \]
    10. *-commutativeN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{\color{blue}{c \cdot a}}{3 \cdot a} \]
    11. lower-*.f64N/A

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

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

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c \cdot a}{3 \cdot a}} \]
    14. lower-*.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{\color{blue}{c \cdot a}}{3 \cdot a} \]
    15. lift-*.f6499.2

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{\color{blue}{3 \cdot a}} \]
  7. Applied rewrites99.2%

    \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{3 \cdot a}} \]
  8. Step-by-step derivation
    1. lift-*.f64N/A

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

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c \cdot a}{3 \cdot a}} \]
    3. mult-flipN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\left(\left(c \cdot a\right) \cdot \frac{1}{3 \cdot a}\right)} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(\color{blue}{\left(c \cdot a\right)} \cdot \frac{1}{3 \cdot a}\right) \]
    5. associate-*l*N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\left(c \cdot \left(a \cdot \frac{1}{3 \cdot a}\right)\right)} \]
    6. mult-flipN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \color{blue}{\frac{a}{3 \cdot a}}\right) \]
    7. *-commutativeN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \frac{a}{\color{blue}{a \cdot 3}}\right) \]
    8. associate-/r*N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \color{blue}{\frac{\frac{a}{a}}{3}}\right) \]
    9. *-inversesN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \frac{\color{blue}{1}}{3}\right) \]
    10. mult-flipN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c}{3}} \]
    11. lower-/.f6499.4

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c}{3}} \]
  9. Applied rewrites99.4%

    \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c}{3}} \]
  10. Add Preprocessing

Alternative 2: 99.4% accurate, 0.9× speedup?

\[\frac{\left(0.3333333333333333 \cdot c\right) \cdot -3}{\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b} \]
(FPCore (a b c)
 :precision binary64
 (/ (* (* 0.3333333333333333 c) -3.0) (+ (sqrt (fma a (* c -3.0) (* b b))) b)))
double code(double a, double b, double c) {
	return ((0.3333333333333333 * c) * -3.0) / (sqrt(fma(a, (c * -3.0), (b * b))) + b);
}
function code(a, b, c)
	return Float64(Float64(Float64(0.3333333333333333 * c) * -3.0) / Float64(sqrt(fma(a, Float64(c * -3.0), Float64(b * b))) + b))
end
code[a_, b_, c_] := N[(N[(N[(0.3333333333333333 * c), $MachinePrecision] * -3.0), $MachinePrecision] / N[(N[Sqrt[N[(a * N[(c * -3.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]
\frac{\left(0.3333333333333333 \cdot c\right) \cdot -3}{\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b}
Derivation
  1. Initial program 31.2%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Step-by-step derivation
    1. lift-+.f64N/A

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

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(-b\right)}}{3 \cdot a} \]
    3. add-flipN/A

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}{3 \cdot a} \]
    4. flip--N/A

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right) \cdot \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}}{3 \cdot a} \]
    5. lower-unsound-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right) \cdot \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}}{3 \cdot a} \]
  3. Applied rewrites32.2%

    \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right) - b \cdot b}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}}{3 \cdot a} \]
  4. Step-by-step derivation
    1. lift--.f64N/A

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

      \[\leadsto \frac{\frac{\color{blue}{\left(\left(c \cdot -3\right) \cdot a + b \cdot b\right)} - b \cdot b}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    3. associate--l+N/A

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

      \[\leadsto \frac{\frac{\color{blue}{\left(c \cdot -3\right)} \cdot a + \left(b \cdot b - b \cdot b\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    5. associate-*l*N/A

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

      \[\leadsto \frac{\frac{c \cdot \color{blue}{\left(-3 \cdot a\right)} + \left(b \cdot b - b \cdot b\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    7. *-commutativeN/A

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

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b - b \cdot b\right)}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    9. +-inverses99.4

      \[\leadsto \frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, \color{blue}{0}\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
  5. Applied rewrites99.4%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
  6. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{\color{blue}{3 \cdot a}} \]
    2. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a}} \]
    3. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}}{3 \cdot a} \]
    4. lift-fma.f64N/A

      \[\leadsto \frac{\frac{\color{blue}{\left(-3 \cdot a\right) \cdot c + 0}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    5. +-rgt-identityN/A

      \[\leadsto \frac{\frac{\color{blue}{\left(-3 \cdot a\right) \cdot c}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    6. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{\left(-3 \cdot a\right) \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-3 \cdot a\right)} \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)} \]
    8. associate-*l*N/A

      \[\leadsto \frac{\color{blue}{-3 \cdot \left(a \cdot c\right)}}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)} \]
    9. times-fracN/A

      \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{a \cdot c}{3 \cdot a}} \]
    10. *-commutativeN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{\color{blue}{c \cdot a}}{3 \cdot a} \]
    11. lower-*.f64N/A

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

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

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c \cdot a}{3 \cdot a}} \]
    14. lower-*.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{\color{blue}{c \cdot a}}{3 \cdot a} \]
    15. lift-*.f6499.2

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{\color{blue}{3 \cdot a}} \]
  7. Applied rewrites99.2%

    \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{3 \cdot a}} \]
  8. Step-by-step derivation
    1. lift-*.f64N/A

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

      \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}} \cdot \frac{c \cdot a}{3 \cdot a} \]
    3. associate-*l/N/A

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

      \[\leadsto \color{blue}{\frac{-3 \cdot \frac{c \cdot a}{3 \cdot a}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}} \]
    5. *-commutativeN/A

      \[\leadsto \frac{\color{blue}{\frac{c \cdot a}{3 \cdot a} \cdot -3}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    6. lower-*.f6499.3

      \[\leadsto \frac{\color{blue}{\frac{c \cdot a}{3 \cdot a} \cdot -3}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\frac{c \cdot a}{\color{blue}{3 \cdot a}} \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    8. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{c \cdot a}{3 \cdot a}} \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    9. mult-flipN/A

      \[\leadsto \frac{\color{blue}{\left(\left(c \cdot a\right) \cdot \frac{1}{3 \cdot a}\right)} \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    10. lift-*.f64N/A

      \[\leadsto \frac{\left(\color{blue}{\left(c \cdot a\right)} \cdot \frac{1}{3 \cdot a}\right) \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    11. associate-*l*N/A

      \[\leadsto \frac{\color{blue}{\left(c \cdot \left(a \cdot \frac{1}{3 \cdot a}\right)\right)} \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    12. mult-flipN/A

      \[\leadsto \frac{\left(c \cdot \color{blue}{\frac{a}{3 \cdot a}}\right) \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    13. *-commutativeN/A

      \[\leadsto \frac{\left(c \cdot \frac{a}{\color{blue}{a \cdot 3}}\right) \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    14. associate-/r*N/A

      \[\leadsto \frac{\left(c \cdot \color{blue}{\frac{\frac{a}{a}}{3}}\right) \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    15. *-inversesN/A

      \[\leadsto \frac{\left(c \cdot \frac{\color{blue}{1}}{3}\right) \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    16. metadata-evalN/A

      \[\leadsto \frac{\left(c \cdot \color{blue}{\frac{1}{3}}\right) \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    17. *-commutativeN/A

      \[\leadsto \frac{\color{blue}{\left(\frac{1}{3} \cdot c\right)} \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
    18. lower-*.f6499.4

      \[\leadsto \frac{\color{blue}{\left(0.3333333333333333 \cdot c\right)} \cdot -3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \]
  9. Applied rewrites99.4%

    \[\leadsto \color{blue}{\frac{\left(0.3333333333333333 \cdot c\right) \cdot -3}{\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b}} \]
  10. Add Preprocessing

Alternative 3: 99.3% accurate, 0.9× speedup?

\[\frac{c \cdot -3}{\left(\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b\right) \cdot 3} \]
(FPCore (a b c)
 :precision binary64
 (/ (* c -3.0) (* (+ (sqrt (fma a (* c -3.0) (* b b))) b) 3.0)))
double code(double a, double b, double c) {
	return (c * -3.0) / ((sqrt(fma(a, (c * -3.0), (b * b))) + b) * 3.0);
}
function code(a, b, c)
	return Float64(Float64(c * -3.0) / Float64(Float64(sqrt(fma(a, Float64(c * -3.0), Float64(b * b))) + b) * 3.0))
end
code[a_, b_, c_] := N[(N[(c * -3.0), $MachinePrecision] / N[(N[(N[Sqrt[N[(a * N[(c * -3.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision] * 3.0), $MachinePrecision]), $MachinePrecision]
\frac{c \cdot -3}{\left(\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b\right) \cdot 3}
Derivation
  1. Initial program 31.2%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Step-by-step derivation
    1. lift-+.f64N/A

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

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(-b\right)}}{3 \cdot a} \]
    3. add-flipN/A

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}{3 \cdot a} \]
    4. flip--N/A

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right) \cdot \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}}{3 \cdot a} \]
    5. lower-unsound-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right) \cdot \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}}{3 \cdot a} \]
  3. Applied rewrites32.2%

    \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right) - b \cdot b}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}}{3 \cdot a} \]
  4. Step-by-step derivation
    1. lift--.f64N/A

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

      \[\leadsto \frac{\frac{\color{blue}{\left(\left(c \cdot -3\right) \cdot a + b \cdot b\right)} - b \cdot b}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    3. associate--l+N/A

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

      \[\leadsto \frac{\frac{\color{blue}{\left(c \cdot -3\right)} \cdot a + \left(b \cdot b - b \cdot b\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    5. associate-*l*N/A

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

      \[\leadsto \frac{\frac{c \cdot \color{blue}{\left(-3 \cdot a\right)} + \left(b \cdot b - b \cdot b\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    7. *-commutativeN/A

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

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b - b \cdot b\right)}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    9. +-inverses99.4

      \[\leadsto \frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, \color{blue}{0}\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
  5. Applied rewrites99.4%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
  6. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{\color{blue}{3 \cdot a}} \]
    2. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a}} \]
    3. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}}{3 \cdot a} \]
    4. lift-fma.f64N/A

      \[\leadsto \frac{\frac{\color{blue}{\left(-3 \cdot a\right) \cdot c + 0}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    5. +-rgt-identityN/A

      \[\leadsto \frac{\frac{\color{blue}{\left(-3 \cdot a\right) \cdot c}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    6. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{\left(-3 \cdot a\right) \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-3 \cdot a\right)} \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)} \]
    8. associate-*l*N/A

      \[\leadsto \frac{\color{blue}{-3 \cdot \left(a \cdot c\right)}}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)} \]
    9. times-fracN/A

      \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{a \cdot c}{3 \cdot a}} \]
    10. *-commutativeN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{\color{blue}{c \cdot a}}{3 \cdot a} \]
    11. lower-*.f64N/A

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

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

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c \cdot a}{3 \cdot a}} \]
    14. lower-*.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{\color{blue}{c \cdot a}}{3 \cdot a} \]
    15. lift-*.f6499.2

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{\color{blue}{3 \cdot a}} \]
  7. Applied rewrites99.2%

    \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{3 \cdot a}} \]
  8. Step-by-step derivation
    1. lift-*.f64N/A

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

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

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{\color{blue}{3 \cdot a}} \]
    4. lift-/.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c \cdot a}{3 \cdot a}} \]
    5. mult-flipN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\left(\left(c \cdot a\right) \cdot \frac{1}{3 \cdot a}\right)} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(\color{blue}{\left(c \cdot a\right)} \cdot \frac{1}{3 \cdot a}\right) \]
    7. associate-*l*N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\left(c \cdot \left(a \cdot \frac{1}{3 \cdot a}\right)\right)} \]
    8. mult-flipN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \color{blue}{\frac{a}{3 \cdot a}}\right) \]
    9. *-commutativeN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \frac{a}{\color{blue}{a \cdot 3}}\right) \]
    10. associate-/r*N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \color{blue}{\frac{\frac{a}{a}}{3}}\right) \]
    11. *-inversesN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \frac{\color{blue}{1}}{3}\right) \]
    12. mult-flipN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c}{3}} \]
    13. frac-timesN/A

      \[\leadsto \color{blue}{\frac{-3 \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot 3}} \]
    14. *-commutativeN/A

      \[\leadsto \frac{\color{blue}{c \cdot -3}}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot 3} \]
    15. lift-*.f64N/A

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

      \[\leadsto \color{blue}{\frac{c \cdot -3}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot 3}} \]
    17. lower-*.f6499.3

      \[\leadsto \frac{c \cdot -3}{\color{blue}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot 3}} \]
  9. Applied rewrites99.3%

    \[\leadsto \color{blue}{\frac{c \cdot -3}{\left(\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b\right) \cdot 3}} \]
  10. Add Preprocessing

Alternative 4: 99.2% accurate, 0.9× speedup?

\[\left(\frac{-3}{\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b} \cdot c\right) \cdot 0.3333333333333333 \]
(FPCore (a b c)
 :precision binary64
 (* (* (/ -3.0 (+ (sqrt (fma a (* c -3.0) (* b b))) b)) c) 0.3333333333333333))
double code(double a, double b, double c) {
	return ((-3.0 / (sqrt(fma(a, (c * -3.0), (b * b))) + b)) * c) * 0.3333333333333333;
}
function code(a, b, c)
	return Float64(Float64(Float64(-3.0 / Float64(sqrt(fma(a, Float64(c * -3.0), Float64(b * b))) + b)) * c) * 0.3333333333333333)
end
code[a_, b_, c_] := N[(N[(N[(-3.0 / N[(N[Sqrt[N[(a * N[(c * -3.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]
\left(\frac{-3}{\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b} \cdot c\right) \cdot 0.3333333333333333
Derivation
  1. Initial program 31.2%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Step-by-step derivation
    1. lift-+.f64N/A

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

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(-b\right)}}{3 \cdot a} \]
    3. add-flipN/A

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}{3 \cdot a} \]
    4. flip--N/A

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right) \cdot \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}}{3 \cdot a} \]
    5. lower-unsound-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} - \left(\mathsf{neg}\left(\left(-b\right)\right)\right) \cdot \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}{\sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} + \left(\mathsf{neg}\left(\left(-b\right)\right)\right)}}}{3 \cdot a} \]
  3. Applied rewrites32.2%

    \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right) - b \cdot b}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}}{3 \cdot a} \]
  4. Step-by-step derivation
    1. lift--.f64N/A

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

      \[\leadsto \frac{\frac{\color{blue}{\left(\left(c \cdot -3\right) \cdot a + b \cdot b\right)} - b \cdot b}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    3. associate--l+N/A

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

      \[\leadsto \frac{\frac{\color{blue}{\left(c \cdot -3\right)} \cdot a + \left(b \cdot b - b \cdot b\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    5. associate-*l*N/A

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

      \[\leadsto \frac{\frac{c \cdot \color{blue}{\left(-3 \cdot a\right)} + \left(b \cdot b - b \cdot b\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    7. *-commutativeN/A

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

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-3 \cdot a, c, b \cdot b - b \cdot b\right)}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    9. +-inverses99.4

      \[\leadsto \frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, \color{blue}{0}\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
  5. Applied rewrites99.4%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
  6. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{\color{blue}{3 \cdot a}} \]
    2. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a}} \]
    3. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}}{3 \cdot a} \]
    4. lift-fma.f64N/A

      \[\leadsto \frac{\frac{\color{blue}{\left(-3 \cdot a\right) \cdot c + 0}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    5. +-rgt-identityN/A

      \[\leadsto \frac{\frac{\color{blue}{\left(-3 \cdot a\right) \cdot c}}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b}}{3 \cdot a} \]
    6. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{\left(-3 \cdot a\right) \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-3 \cdot a\right)} \cdot c}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)} \]
    8. associate-*l*N/A

      \[\leadsto \frac{\color{blue}{-3 \cdot \left(a \cdot c\right)}}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b\right) \cdot \left(3 \cdot a\right)} \]
    9. times-fracN/A

      \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{a \cdot c}{3 \cdot a}} \]
    10. *-commutativeN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{\color{blue}{c \cdot a}}{3 \cdot a} \]
    11. lower-*.f64N/A

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

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

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c \cdot a}{3 \cdot a}} \]
    14. lower-*.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{\color{blue}{c \cdot a}}{3 \cdot a} \]
    15. lift-*.f6499.2

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{\color{blue}{3 \cdot a}} \]
  7. Applied rewrites99.2%

    \[\leadsto \color{blue}{\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{3 \cdot a}} \]
  8. Step-by-step derivation
    1. lift-*.f64N/A

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

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \frac{c \cdot a}{\color{blue}{3 \cdot a}} \]
    3. lift-/.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\frac{c \cdot a}{3 \cdot a}} \]
    4. mult-flipN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\left(\left(c \cdot a\right) \cdot \frac{1}{3 \cdot a}\right)} \]
    5. lift-*.f64N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(\color{blue}{\left(c \cdot a\right)} \cdot \frac{1}{3 \cdot a}\right) \]
    6. associate-*l*N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \color{blue}{\left(c \cdot \left(a \cdot \frac{1}{3 \cdot a}\right)\right)} \]
    7. mult-flipN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \color{blue}{\frac{a}{3 \cdot a}}\right) \]
    8. *-commutativeN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \frac{a}{\color{blue}{a \cdot 3}}\right) \]
    9. associate-/r*N/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \color{blue}{\frac{\frac{a}{a}}{3}}\right) \]
    10. *-inversesN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \frac{\color{blue}{1}}{3}\right) \]
    11. metadata-evalN/A

      \[\leadsto \frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot \left(c \cdot \color{blue}{\frac{1}{3}}\right) \]
    12. associate-*r*N/A

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

      \[\leadsto \color{blue}{\left(\frac{-3}{\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} + b} \cdot c\right) \cdot \frac{1}{3}} \]
  9. Applied rewrites99.2%

    \[\leadsto \color{blue}{\left(\frac{-3}{\sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)} + b} \cdot c\right) \cdot 0.3333333333333333} \]
  10. Add Preprocessing

Alternative 5: 84.5% accurate, 0.5× speedup?

\[\begin{array}{l} \mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \leq -1 \cdot 10^{-5}:\\ \;\;\;\;\left(\left(b - \sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)}\right) \cdot 0.3333333333333333\right) \cdot \frac{-1}{a}\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot \frac{c}{b}\\ \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)) -1e-5)
   (*
    (* (- b (sqrt (fma (* c -3.0) a (* b b)))) 0.3333333333333333)
    (/ -1.0 a))
   (* -0.5 (/ c b))))
double code(double a, double b, double c) {
	double tmp;
	if (((-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)) <= -1e-5) {
		tmp = ((b - sqrt(fma((c * -3.0), a, (b * b)))) * 0.3333333333333333) * (-1.0 / a);
	} else {
		tmp = -0.5 * (c / b);
	}
	return tmp;
}
function code(a, b, c)
	tmp = 0.0
	if (Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) <= -1e-5)
		tmp = Float64(Float64(Float64(b - sqrt(fma(Float64(c * -3.0), a, Float64(b * b)))) * 0.3333333333333333) * Float64(-1.0 / a));
	else
		tmp = Float64(-0.5 * 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[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision], -1e-5], N[(N[(N[(b - N[Sqrt[N[(N[(c * -3.0), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision] * N[(-1.0 / a), $MachinePrecision]), $MachinePrecision], N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \leq -1 \cdot 10^{-5}:\\
\;\;\;\;\left(\left(b - \sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)}\right) \cdot 0.3333333333333333\right) \cdot \frac{-1}{a}\\

\mathbf{else}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b}\\


\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 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a)) < -1.00000000000000008e-5

    1. Initial program 31.2%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\color{blue}{3 \cdot a}} \]
      3. associate-/r*N/A

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

        \[\leadsto \color{blue}{\frac{\mathsf{neg}\left(\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3}\right)}{\mathsf{neg}\left(a\right)}} \]
      5. mult-flipN/A

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

        \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3}\right)\right) \cdot \frac{1}{\mathsf{neg}\left(a\right)}} \]
    3. Applied rewrites31.2%

      \[\leadsto \color{blue}{\left(\left(b - \sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)}\right) \cdot 0.3333333333333333\right) \cdot \frac{-1}{a}} \]

    if -1.00000000000000008e-5 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a))

    1. Initial program 31.2%

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

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

        \[\leadsto \frac{-1}{2} \cdot \color{blue}{\frac{c}{b}} \]
      2. lower-/.f6481.3

        \[\leadsto -0.5 \cdot \frac{c}{\color{blue}{b}} \]
    4. Applied rewrites81.3%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 6: 84.5% accurate, 0.5× speedup?

\[\begin{array}{l} \mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \leq -1 \cdot 10^{-5}:\\ \;\;\;\;\frac{\left(b - \sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)}\right) \cdot -0.3333333333333333}{a}\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot \frac{c}{b}\\ \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)) -1e-5)
   (/ (* (- b (sqrt (fma (* c -3.0) a (* b b)))) -0.3333333333333333) a)
   (* -0.5 (/ c b))))
double code(double a, double b, double c) {
	double tmp;
	if (((-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)) <= -1e-5) {
		tmp = ((b - sqrt(fma((c * -3.0), a, (b * b)))) * -0.3333333333333333) / a;
	} else {
		tmp = -0.5 * (c / b);
	}
	return tmp;
}
function code(a, b, c)
	tmp = 0.0
	if (Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) <= -1e-5)
		tmp = Float64(Float64(Float64(b - sqrt(fma(Float64(c * -3.0), a, Float64(b * b)))) * -0.3333333333333333) / a);
	else
		tmp = Float64(-0.5 * 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[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision], -1e-5], N[(N[(N[(b - N[Sqrt[N[(N[(c * -3.0), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -0.3333333333333333), $MachinePrecision] / a), $MachinePrecision], N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \leq -1 \cdot 10^{-5}:\\
\;\;\;\;\frac{\left(b - \sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)}\right) \cdot -0.3333333333333333}{a}\\

\mathbf{else}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b}\\


\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 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a)) < -1.00000000000000008e-5

    1. Initial program 31.2%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\color{blue}{3 \cdot a}} \]
      3. associate-/r*N/A

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

        \[\leadsto \color{blue}{\frac{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3}}{a}} \]
    3. Applied rewrites31.2%

      \[\leadsto \color{blue}{\frac{\left(b - \sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)}\right) \cdot -0.3333333333333333}{a}} \]

    if -1.00000000000000008e-5 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a))

    1. Initial program 31.2%

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

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

        \[\leadsto \frac{-1}{2} \cdot \color{blue}{\frac{c}{b}} \]
      2. lower-/.f6481.3

        \[\leadsto -0.5 \cdot \frac{c}{\color{blue}{b}} \]
    4. Applied rewrites81.3%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 7: 84.5% accurate, 0.5× speedup?

\[\begin{array}{l} \mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \leq -1 \cdot 10^{-5}:\\ \;\;\;\;\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} - b\right) \cdot \frac{0.3333333333333333}{a}\\ \mathbf{else}:\\ \;\;\;\;-0.5 \cdot \frac{c}{b}\\ \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)) -1e-5)
   (* (- (sqrt (fma (* c -3.0) a (* b b))) b) (/ 0.3333333333333333 a))
   (* -0.5 (/ c b))))
double code(double a, double b, double c) {
	double tmp;
	if (((-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)) <= -1e-5) {
		tmp = (sqrt(fma((c * -3.0), a, (b * b))) - b) * (0.3333333333333333 / a);
	} else {
		tmp = -0.5 * (c / b);
	}
	return tmp;
}
function code(a, b, c)
	tmp = 0.0
	if (Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) <= -1e-5)
		tmp = Float64(Float64(sqrt(fma(Float64(c * -3.0), a, Float64(b * b))) - b) * Float64(0.3333333333333333 / a));
	else
		tmp = Float64(-0.5 * 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[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision], -1e-5], N[(N[(N[Sqrt[N[(N[(c * -3.0), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] * N[(0.3333333333333333 / a), $MachinePrecision]), $MachinePrecision], N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\mathbf{if}\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \leq -1 \cdot 10^{-5}:\\
\;\;\;\;\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} - b\right) \cdot \frac{0.3333333333333333}{a}\\

\mathbf{else}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b}\\


\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 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a)) < -1.00000000000000008e-5

    1. Initial program 31.2%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}} \]
      2. mult-flipN/A

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

        \[\leadsto \color{blue}{\left(\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}\right) \cdot \frac{1}{3 \cdot a}} \]
    3. Applied rewrites31.2%

      \[\leadsto \color{blue}{\left(\sqrt{\mathsf{fma}\left(c \cdot -3, a, b \cdot b\right)} - b\right) \cdot \frac{0.3333333333333333}{a}} \]

    if -1.00000000000000008e-5 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a))

    1. Initial program 31.2%

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

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

        \[\leadsto \frac{-1}{2} \cdot \color{blue}{\frac{c}{b}} \]
      2. lower-/.f6481.3

        \[\leadsto -0.5 \cdot \frac{c}{\color{blue}{b}} \]
    4. Applied rewrites81.3%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 8: 81.3% accurate, 3.3× speedup?

\[-0.5 \cdot \frac{c}{b} \]
(FPCore (a b c) :precision binary64 (* -0.5 (/ c b)))
double code(double a, double b, double c) {
	return -0.5 * (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 = (-0.5d0) * (c / b)
end function
public static double code(double a, double b, double c) {
	return -0.5 * (c / b);
}
def code(a, b, c):
	return -0.5 * (c / b)
function code(a, b, c)
	return Float64(-0.5 * Float64(c / b))
end
function tmp = code(a, b, c)
	tmp = -0.5 * (c / b);
end
code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]
-0.5 \cdot \frac{c}{b}
Derivation
  1. Initial program 31.2%

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

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

      \[\leadsto \frac{-1}{2} \cdot \color{blue}{\frac{c}{b}} \]
    2. lower-/.f6481.3

      \[\leadsto -0.5 \cdot \frac{c}{\color{blue}{b}} \]
  4. Applied rewrites81.3%

    \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b}} \]
  5. Add Preprocessing

Reproduce

?
herbie shell --seed 2025167 
(FPCore (a b c)
  :name "Cubic critical, medium range"
  :precision binary64
  :pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))