quad2m (problem 3.2.1, negative)

Percentage Accurate: 52.5% → 84.7%
Time: 18.7s
Alternatives: 6
Speedup: 1.2×

Specification

?
\[\begin{array}{l} \\ \frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \end{array} \]
(FPCore (a b_2 c)
 :precision binary64
 (/ (- (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))
double code(double a, double b_2, double c) {
	return (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / 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_2, c)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b_2
    real(8), intent (in) :: c
    code = (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / a
end function
public static double code(double a, double b_2, double c) {
	return (-b_2 - Math.sqrt(((b_2 * b_2) - (a * c)))) / a;
}
def code(a, b_2, c):
	return (-b_2 - math.sqrt(((b_2 * b_2) - (a * c)))) / a
function code(a, b_2, c)
	return Float64(Float64(Float64(-b_2) - sqrt(Float64(Float64(b_2 * b_2) - Float64(a * c)))) / a)
end
function tmp = code(a, b_2, c)
	tmp = (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / a;
end
code[a_, b$95$2_, c_] := N[(N[((-b$95$2) - N[Sqrt[N[(N[(b$95$2 * b$95$2), $MachinePrecision] - N[(a * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{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: 52.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \end{array} \]
(FPCore (a b_2 c)
 :precision binary64
 (/ (- (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))
double code(double a, double b_2, double c) {
	return (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / 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_2, c)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b_2
    real(8), intent (in) :: c
    code = (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / a
end function
public static double code(double a, double b_2, double c) {
	return (-b_2 - Math.sqrt(((b_2 * b_2) - (a * c)))) / a;
}
def code(a, b_2, c):
	return (-b_2 - math.sqrt(((b_2 * b_2) - (a * c)))) / a
function code(a, b_2, c)
	return Float64(Float64(Float64(-b_2) - sqrt(Float64(Float64(b_2 * b_2) - Float64(a * c)))) / a)
end
function tmp = code(a, b_2, c)
	tmp = (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / a;
end
code[a_, b$95$2_, c_] := N[(N[((-b$95$2) - N[Sqrt[N[(N[(b$95$2 * b$95$2), $MachinePrecision] - N[(a * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a}
\end{array}

Alternative 1: 84.7% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b\_2 \leq -2 \cdot 10^{-112}:\\ \;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\ \mathbf{elif}\;b\_2 \leq 10^{+103}:\\ \;\;\;\;\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a}\\ \mathbf{else}:\\ \;\;\;\;\frac{-2 \cdot b\_2}{a}\\ \end{array} \end{array} \]
(FPCore (a b_2 c)
 :precision binary64
 (if (<= b_2 -2e-112)
   (* -0.5 (/ c b_2))
   (if (<= b_2 1e+103)
     (/ (- (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a)
     (/ (* -2.0 b_2) a))))
double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -2e-112) {
		tmp = -0.5 * (c / b_2);
	} else if (b_2 <= 1e+103) {
		tmp = (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / a;
	} else {
		tmp = (-2.0 * b_2) / a;
	}
	return tmp;
}
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_2, c)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b_2
    real(8), intent (in) :: c
    real(8) :: tmp
    if (b_2 <= (-2d-112)) then
        tmp = (-0.5d0) * (c / b_2)
    else if (b_2 <= 1d+103) then
        tmp = (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / a
    else
        tmp = ((-2.0d0) * b_2) / a
    end if
    code = tmp
end function
public static double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -2e-112) {
		tmp = -0.5 * (c / b_2);
	} else if (b_2 <= 1e+103) {
		tmp = (-b_2 - Math.sqrt(((b_2 * b_2) - (a * c)))) / a;
	} else {
		tmp = (-2.0 * b_2) / a;
	}
	return tmp;
}
def code(a, b_2, c):
	tmp = 0
	if b_2 <= -2e-112:
		tmp = -0.5 * (c / b_2)
	elif b_2 <= 1e+103:
		tmp = (-b_2 - math.sqrt(((b_2 * b_2) - (a * c)))) / a
	else:
		tmp = (-2.0 * b_2) / a
	return tmp
function code(a, b_2, c)
	tmp = 0.0
	if (b_2 <= -2e-112)
		tmp = Float64(-0.5 * Float64(c / b_2));
	elseif (b_2 <= 1e+103)
		tmp = Float64(Float64(Float64(-b_2) - sqrt(Float64(Float64(b_2 * b_2) - Float64(a * c)))) / a);
	else
		tmp = Float64(Float64(-2.0 * b_2) / a);
	end
	return tmp
end
function tmp_2 = code(a, b_2, c)
	tmp = 0.0;
	if (b_2 <= -2e-112)
		tmp = -0.5 * (c / b_2);
	elseif (b_2 <= 1e+103)
		tmp = (-b_2 - sqrt(((b_2 * b_2) - (a * c)))) / a;
	else
		tmp = (-2.0 * b_2) / a;
	end
	tmp_2 = tmp;
end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -2e-112], N[(-0.5 * N[(c / b$95$2), $MachinePrecision]), $MachinePrecision], If[LessEqual[b$95$2, 1e+103], N[(N[((-b$95$2) - N[Sqrt[N[(N[(b$95$2 * b$95$2), $MachinePrecision] - N[(a * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision], N[(N[(-2.0 * b$95$2), $MachinePrecision] / a), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -2 \cdot 10^{-112}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\

\mathbf{elif}\;b\_2 \leq 10^{+103}:\\
\;\;\;\;\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a}\\

\mathbf{else}:\\
\;\;\;\;\frac{-2 \cdot b\_2}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b_2 < -1.9999999999999999e-112

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around -inf

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b\_2}} \]
    3. Applied rewrites34.6%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b\_2}} \]

    if -1.9999999999999999e-112 < b_2 < 1e103

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]

    if 1e103 < b_2

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around inf

      \[\leadsto \frac{\color{blue}{-2 \cdot b\_2}}{a} \]
    3. Applied rewrites35.7%

      \[\leadsto \frac{\color{blue}{-2 \cdot b\_2}}{a} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 2: 79.7% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b\_2 \leq -2 \cdot 10^{-112}:\\ \;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\ \mathbf{elif}\;b\_2 \leq 1.95 \cdot 10^{-74}:\\ \;\;\;\;c \cdot \sqrt{\frac{\frac{-1}{a}}{c}}\\ \mathbf{else}:\\ \;\;\;\;\frac{-2 \cdot b\_2}{a}\\ \end{array} \end{array} \]
(FPCore (a b_2 c)
 :precision binary64
 (if (<= b_2 -2e-112)
   (* -0.5 (/ c b_2))
   (if (<= b_2 1.95e-74) (* c (sqrt (/ (/ -1.0 a) c))) (/ (* -2.0 b_2) a))))
double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -2e-112) {
		tmp = -0.5 * (c / b_2);
	} else if (b_2 <= 1.95e-74) {
		tmp = c * sqrt(((-1.0 / a) / c));
	} else {
		tmp = (-2.0 * b_2) / a;
	}
	return tmp;
}
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_2, c)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b_2
    real(8), intent (in) :: c
    real(8) :: tmp
    if (b_2 <= (-2d-112)) then
        tmp = (-0.5d0) * (c / b_2)
    else if (b_2 <= 1.95d-74) then
        tmp = c * sqrt((((-1.0d0) / a) / c))
    else
        tmp = ((-2.0d0) * b_2) / a
    end if
    code = tmp
end function
public static double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -2e-112) {
		tmp = -0.5 * (c / b_2);
	} else if (b_2 <= 1.95e-74) {
		tmp = c * Math.sqrt(((-1.0 / a) / c));
	} else {
		tmp = (-2.0 * b_2) / a;
	}
	return tmp;
}
def code(a, b_2, c):
	tmp = 0
	if b_2 <= -2e-112:
		tmp = -0.5 * (c / b_2)
	elif b_2 <= 1.95e-74:
		tmp = c * math.sqrt(((-1.0 / a) / c))
	else:
		tmp = (-2.0 * b_2) / a
	return tmp
function code(a, b_2, c)
	tmp = 0.0
	if (b_2 <= -2e-112)
		tmp = Float64(-0.5 * Float64(c / b_2));
	elseif (b_2 <= 1.95e-74)
		tmp = Float64(c * sqrt(Float64(Float64(-1.0 / a) / c)));
	else
		tmp = Float64(Float64(-2.0 * b_2) / a);
	end
	return tmp
end
function tmp_2 = code(a, b_2, c)
	tmp = 0.0;
	if (b_2 <= -2e-112)
		tmp = -0.5 * (c / b_2);
	elseif (b_2 <= 1.95e-74)
		tmp = c * sqrt(((-1.0 / a) / c));
	else
		tmp = (-2.0 * b_2) / a;
	end
	tmp_2 = tmp;
end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -2e-112], N[(-0.5 * N[(c / b$95$2), $MachinePrecision]), $MachinePrecision], If[LessEqual[b$95$2, 1.95e-74], N[(c * N[Sqrt[N[(N[(-1.0 / a), $MachinePrecision] / c), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(N[(-2.0 * b$95$2), $MachinePrecision] / a), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -2 \cdot 10^{-112}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\

\mathbf{elif}\;b\_2 \leq 1.95 \cdot 10^{-74}:\\
\;\;\;\;c \cdot \sqrt{\frac{\frac{-1}{a}}{c}}\\

\mathbf{else}:\\
\;\;\;\;\frac{-2 \cdot b\_2}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b_2 < -1.9999999999999999e-112

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around -inf

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b\_2}} \]
    3. Applied rewrites34.6%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b\_2}} \]

    if -1.9999999999999999e-112 < b_2 < 1.9500000000000001e-74

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in a around -inf

      \[\leadsto \color{blue}{\sqrt{-1 \cdot \frac{c}{a}}} \]
    3. Applied rewrites17.1%

      \[\leadsto \color{blue}{\sqrt{-1 \cdot \frac{c}{a}}} \]
    4. Applied rewrites17.1%

      \[\leadsto \color{blue}{\sqrt{-\frac{c}{a}}} \]
    5. Taylor expanded in c around inf

      \[\leadsto c \cdot \color{blue}{\sqrt{\frac{-1}{a \cdot c}}} \]
    6. Applied rewrites27.3%

      \[\leadsto c \cdot \color{blue}{\sqrt{\frac{-1}{a \cdot c}}} \]
    7. Applied rewrites27.7%

      \[\leadsto c \cdot \sqrt{\frac{\frac{-1}{a}}{c}} \]

    if 1.9500000000000001e-74 < b_2

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around inf

      \[\leadsto \frac{\color{blue}{-2 \cdot b\_2}}{a} \]
    3. Applied rewrites35.7%

      \[\leadsto \frac{\color{blue}{-2 \cdot b\_2}}{a} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 3: 79.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b\_2 \leq -2 \cdot 10^{-112}:\\ \;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\ \mathbf{elif}\;b\_2 \leq 1.95 \cdot 10^{-74}:\\ \;\;\;\;\frac{-\sqrt{-a \cdot c}}{a}\\ \mathbf{else}:\\ \;\;\;\;\frac{-2 \cdot b\_2}{a}\\ \end{array} \end{array} \]
(FPCore (a b_2 c)
 :precision binary64
 (if (<= b_2 -2e-112)
   (* -0.5 (/ c b_2))
   (if (<= b_2 1.95e-74) (/ (- (sqrt (- (* a c)))) a) (/ (* -2.0 b_2) a))))
double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -2e-112) {
		tmp = -0.5 * (c / b_2);
	} else if (b_2 <= 1.95e-74) {
		tmp = -sqrt(-(a * c)) / a;
	} else {
		tmp = (-2.0 * b_2) / a;
	}
	return tmp;
}
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_2, c)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b_2
    real(8), intent (in) :: c
    real(8) :: tmp
    if (b_2 <= (-2d-112)) then
        tmp = (-0.5d0) * (c / b_2)
    else if (b_2 <= 1.95d-74) then
        tmp = -sqrt(-(a * c)) / a
    else
        tmp = ((-2.0d0) * b_2) / a
    end if
    code = tmp
end function
public static double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -2e-112) {
		tmp = -0.5 * (c / b_2);
	} else if (b_2 <= 1.95e-74) {
		tmp = -Math.sqrt(-(a * c)) / a;
	} else {
		tmp = (-2.0 * b_2) / a;
	}
	return tmp;
}
def code(a, b_2, c):
	tmp = 0
	if b_2 <= -2e-112:
		tmp = -0.5 * (c / b_2)
	elif b_2 <= 1.95e-74:
		tmp = -math.sqrt(-(a * c)) / a
	else:
		tmp = (-2.0 * b_2) / a
	return tmp
function code(a, b_2, c)
	tmp = 0.0
	if (b_2 <= -2e-112)
		tmp = Float64(-0.5 * Float64(c / b_2));
	elseif (b_2 <= 1.95e-74)
		tmp = Float64(Float64(-sqrt(Float64(-Float64(a * c)))) / a);
	else
		tmp = Float64(Float64(-2.0 * b_2) / a);
	end
	return tmp
end
function tmp_2 = code(a, b_2, c)
	tmp = 0.0;
	if (b_2 <= -2e-112)
		tmp = -0.5 * (c / b_2);
	elseif (b_2 <= 1.95e-74)
		tmp = -sqrt(-(a * c)) / a;
	else
		tmp = (-2.0 * b_2) / a;
	end
	tmp_2 = tmp;
end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -2e-112], N[(-0.5 * N[(c / b$95$2), $MachinePrecision]), $MachinePrecision], If[LessEqual[b$95$2, 1.95e-74], N[((-N[Sqrt[(-N[(a * c), $MachinePrecision])], $MachinePrecision]) / a), $MachinePrecision], N[(N[(-2.0 * b$95$2), $MachinePrecision] / a), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -2 \cdot 10^{-112}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\

\mathbf{elif}\;b\_2 \leq 1.95 \cdot 10^{-74}:\\
\;\;\;\;\frac{-\sqrt{-a \cdot c}}{a}\\

\mathbf{else}:\\
\;\;\;\;\frac{-2 \cdot b\_2}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b_2 < -1.9999999999999999e-112

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around -inf

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b\_2}} \]
    3. Applied rewrites34.6%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b\_2}} \]

    if -1.9999999999999999e-112 < b_2 < 1.9500000000000001e-74

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around 0

      \[\leadsto \frac{\color{blue}{-1 \cdot \sqrt{\mathsf{neg}\left(a \cdot c\right)}}}{a} \]
    3. Applied rewrites28.7%

      \[\leadsto \frac{\color{blue}{-1 \cdot \sqrt{-a \cdot c}}}{a} \]
    4. Applied rewrites28.7%

      \[\leadsto \frac{\color{blue}{-\sqrt{-a \cdot c}}}{a} \]

    if 1.9500000000000001e-74 < b_2

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around inf

      \[\leadsto \frac{\color{blue}{-2 \cdot b\_2}}{a} \]
    3. Applied rewrites35.7%

      \[\leadsto \frac{\color{blue}{-2 \cdot b\_2}}{a} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 4: 70.8% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b\_2 \leq -5.6 \cdot 10^{-257}:\\ \;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\ \mathbf{elif}\;b\_2 \leq 9 \cdot 10^{-131}:\\ \;\;\;\;\sqrt{-\frac{c}{a}}\\ \mathbf{else}:\\ \;\;\;\;\frac{-2 \cdot b\_2}{a}\\ \end{array} \end{array} \]
(FPCore (a b_2 c)
 :precision binary64
 (if (<= b_2 -5.6e-257)
   (* -0.5 (/ c b_2))
   (if (<= b_2 9e-131) (sqrt (- (/ c a))) (/ (* -2.0 b_2) a))))
double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -5.6e-257) {
		tmp = -0.5 * (c / b_2);
	} else if (b_2 <= 9e-131) {
		tmp = sqrt(-(c / a));
	} else {
		tmp = (-2.0 * b_2) / a;
	}
	return tmp;
}
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_2, c)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b_2
    real(8), intent (in) :: c
    real(8) :: tmp
    if (b_2 <= (-5.6d-257)) then
        tmp = (-0.5d0) * (c / b_2)
    else if (b_2 <= 9d-131) then
        tmp = sqrt(-(c / a))
    else
        tmp = ((-2.0d0) * b_2) / a
    end if
    code = tmp
end function
public static double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -5.6e-257) {
		tmp = -0.5 * (c / b_2);
	} else if (b_2 <= 9e-131) {
		tmp = Math.sqrt(-(c / a));
	} else {
		tmp = (-2.0 * b_2) / a;
	}
	return tmp;
}
def code(a, b_2, c):
	tmp = 0
	if b_2 <= -5.6e-257:
		tmp = -0.5 * (c / b_2)
	elif b_2 <= 9e-131:
		tmp = math.sqrt(-(c / a))
	else:
		tmp = (-2.0 * b_2) / a
	return tmp
function code(a, b_2, c)
	tmp = 0.0
	if (b_2 <= -5.6e-257)
		tmp = Float64(-0.5 * Float64(c / b_2));
	elseif (b_2 <= 9e-131)
		tmp = sqrt(Float64(-Float64(c / a)));
	else
		tmp = Float64(Float64(-2.0 * b_2) / a);
	end
	return tmp
end
function tmp_2 = code(a, b_2, c)
	tmp = 0.0;
	if (b_2 <= -5.6e-257)
		tmp = -0.5 * (c / b_2);
	elseif (b_2 <= 9e-131)
		tmp = sqrt(-(c / a));
	else
		tmp = (-2.0 * b_2) / a;
	end
	tmp_2 = tmp;
end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -5.6e-257], N[(-0.5 * N[(c / b$95$2), $MachinePrecision]), $MachinePrecision], If[LessEqual[b$95$2, 9e-131], N[Sqrt[(-N[(c / a), $MachinePrecision])], $MachinePrecision], N[(N[(-2.0 * b$95$2), $MachinePrecision] / a), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -5.6 \cdot 10^{-257}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\

\mathbf{elif}\;b\_2 \leq 9 \cdot 10^{-131}:\\
\;\;\;\;\sqrt{-\frac{c}{a}}\\

\mathbf{else}:\\
\;\;\;\;\frac{-2 \cdot b\_2}{a}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b_2 < -5.60000000000000002e-257

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around -inf

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b\_2}} \]
    3. Applied rewrites34.6%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b\_2}} \]

    if -5.60000000000000002e-257 < b_2 < 9.0000000000000004e-131

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in a around -inf

      \[\leadsto \color{blue}{\sqrt{-1 \cdot \frac{c}{a}}} \]
    3. Applied rewrites17.1%

      \[\leadsto \color{blue}{\sqrt{-1 \cdot \frac{c}{a}}} \]
    4. Applied rewrites17.1%

      \[\leadsto \color{blue}{\sqrt{-\frac{c}{a}}} \]

    if 9.0000000000000004e-131 < b_2

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around inf

      \[\leadsto \frac{\color{blue}{-2 \cdot b\_2}}{a} \]
    3. Applied rewrites35.7%

      \[\leadsto \frac{\color{blue}{-2 \cdot b\_2}}{a} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 5: 42.1% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b\_2 \leq -5.6 \cdot 10^{-257}:\\ \;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{-\frac{c}{a}}\\ \end{array} \end{array} \]
(FPCore (a b_2 c)
 :precision binary64
 (if (<= b_2 -5.6e-257) (* -0.5 (/ c b_2)) (sqrt (- (/ c a)))))
double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -5.6e-257) {
		tmp = -0.5 * (c / b_2);
	} else {
		tmp = sqrt(-(c / a));
	}
	return tmp;
}
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_2, c)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b_2
    real(8), intent (in) :: c
    real(8) :: tmp
    if (b_2 <= (-5.6d-257)) then
        tmp = (-0.5d0) * (c / b_2)
    else
        tmp = sqrt(-(c / a))
    end if
    code = tmp
end function
public static double code(double a, double b_2, double c) {
	double tmp;
	if (b_2 <= -5.6e-257) {
		tmp = -0.5 * (c / b_2);
	} else {
		tmp = Math.sqrt(-(c / a));
	}
	return tmp;
}
def code(a, b_2, c):
	tmp = 0
	if b_2 <= -5.6e-257:
		tmp = -0.5 * (c / b_2)
	else:
		tmp = math.sqrt(-(c / a))
	return tmp
function code(a, b_2, c)
	tmp = 0.0
	if (b_2 <= -5.6e-257)
		tmp = Float64(-0.5 * Float64(c / b_2));
	else
		tmp = sqrt(Float64(-Float64(c / a)));
	end
	return tmp
end
function tmp_2 = code(a, b_2, c)
	tmp = 0.0;
	if (b_2 <= -5.6e-257)
		tmp = -0.5 * (c / b_2);
	else
		tmp = sqrt(-(c / a));
	end
	tmp_2 = tmp;
end
code[a_, b$95$2_, c_] := If[LessEqual[b$95$2, -5.6e-257], N[(-0.5 * N[(c / b$95$2), $MachinePrecision]), $MachinePrecision], N[Sqrt[(-N[(c / a), $MachinePrecision])], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b\_2 \leq -5.6 \cdot 10^{-257}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b\_2}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b_2 < -5.60000000000000002e-257

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in b_2 around -inf

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b\_2}} \]
    3. Applied rewrites34.6%

      \[\leadsto \color{blue}{-0.5 \cdot \frac{c}{b\_2}} \]

    if -5.60000000000000002e-257 < b_2

    1. Initial program 52.5%

      \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
    2. Taylor expanded in a around -inf

      \[\leadsto \color{blue}{\sqrt{-1 \cdot \frac{c}{a}}} \]
    3. Applied rewrites17.1%

      \[\leadsto \color{blue}{\sqrt{-1 \cdot \frac{c}{a}}} \]
    4. Applied rewrites17.1%

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

Alternative 6: 17.1% accurate, 2.6× speedup?

\[\begin{array}{l} \\ \sqrt{-\frac{c}{a}} \end{array} \]
(FPCore (a b_2 c) :precision binary64 (sqrt (- (/ c a))))
double code(double a, double b_2, double c) {
	return sqrt(-(c / 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_2, c)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b_2
    real(8), intent (in) :: c
    code = sqrt(-(c / a))
end function
public static double code(double a, double b_2, double c) {
	return Math.sqrt(-(c / a));
}
def code(a, b_2, c):
	return math.sqrt(-(c / a))
function code(a, b_2, c)
	return sqrt(Float64(-Float64(c / a)))
end
function tmp = code(a, b_2, c)
	tmp = sqrt(-(c / a));
end
code[a_, b$95$2_, c_] := N[Sqrt[(-N[(c / a), $MachinePrecision])], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{-\frac{c}{a}}
\end{array}
Derivation
  1. Initial program 52.5%

    \[\frac{\left(-b\_2\right) - \sqrt{b\_2 \cdot b\_2 - a \cdot c}}{a} \]
  2. Taylor expanded in a around -inf

    \[\leadsto \color{blue}{\sqrt{-1 \cdot \frac{c}{a}}} \]
  3. Applied rewrites17.1%

    \[\leadsto \color{blue}{\sqrt{-1 \cdot \frac{c}{a}}} \]
  4. Applied rewrites17.1%

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

Developer Target 1: 99.7% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{\left|a\right|} \cdot \sqrt{\left|c\right|}\\ t_1 := \begin{array}{l} \mathbf{if}\;\mathsf{copysign}\left(a, c\right) = a:\\ \;\;\;\;\sqrt{\left|b\_2\right| - t\_0} \cdot \sqrt{\left|b\_2\right| + t\_0}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{hypot}\left(b\_2, t\_0\right)\\ \end{array}\\ \mathbf{if}\;b\_2 < 0:\\ \;\;\;\;\frac{c}{t\_1 - b\_2}\\ \mathbf{else}:\\ \;\;\;\;\frac{b\_2 + t\_1}{-a}\\ \end{array} \end{array} \]
(FPCore (a b_2 c)
 :precision binary64
 (let* ((t_0 (* (sqrt (fabs a)) (sqrt (fabs c))))
        (t_1
         (if (== (copysign a c) a)
           (* (sqrt (- (fabs b_2) t_0)) (sqrt (+ (fabs b_2) t_0)))
           (hypot b_2 t_0))))
   (if (< b_2 0.0) (/ c (- t_1 b_2)) (/ (+ b_2 t_1) (- a)))))
double code(double a, double b_2, double c) {
	double t_0 = sqrt(fabs(a)) * sqrt(fabs(c));
	double tmp;
	if (copysign(a, c) == a) {
		tmp = sqrt((fabs(b_2) - t_0)) * sqrt((fabs(b_2) + t_0));
	} else {
		tmp = hypot(b_2, t_0);
	}
	double t_1 = tmp;
	double tmp_1;
	if (b_2 < 0.0) {
		tmp_1 = c / (t_1 - b_2);
	} else {
		tmp_1 = (b_2 + t_1) / -a;
	}
	return tmp_1;
}
public static double code(double a, double b_2, double c) {
	double t_0 = Math.sqrt(Math.abs(a)) * Math.sqrt(Math.abs(c));
	double tmp;
	if (Math.copySign(a, c) == a) {
		tmp = Math.sqrt((Math.abs(b_2) - t_0)) * Math.sqrt((Math.abs(b_2) + t_0));
	} else {
		tmp = Math.hypot(b_2, t_0);
	}
	double t_1 = tmp;
	double tmp_1;
	if (b_2 < 0.0) {
		tmp_1 = c / (t_1 - b_2);
	} else {
		tmp_1 = (b_2 + t_1) / -a;
	}
	return tmp_1;
}
def code(a, b_2, c):
	t_0 = math.sqrt(math.fabs(a)) * math.sqrt(math.fabs(c))
	tmp = 0
	if math.copysign(a, c) == a:
		tmp = math.sqrt((math.fabs(b_2) - t_0)) * math.sqrt((math.fabs(b_2) + t_0))
	else:
		tmp = math.hypot(b_2, t_0)
	t_1 = tmp
	tmp_1 = 0
	if b_2 < 0.0:
		tmp_1 = c / (t_1 - b_2)
	else:
		tmp_1 = (b_2 + t_1) / -a
	return tmp_1
function code(a, b_2, c)
	t_0 = Float64(sqrt(abs(a)) * sqrt(abs(c)))
	tmp = 0.0
	if (copysign(a, c) == a)
		tmp = Float64(sqrt(Float64(abs(b_2) - t_0)) * sqrt(Float64(abs(b_2) + t_0)));
	else
		tmp = hypot(b_2, t_0);
	end
	t_1 = tmp
	tmp_1 = 0.0
	if (b_2 < 0.0)
		tmp_1 = Float64(c / Float64(t_1 - b_2));
	else
		tmp_1 = Float64(Float64(b_2 + t_1) / Float64(-a));
	end
	return tmp_1
end
function tmp_3 = code(a, b_2, c)
	t_0 = sqrt(abs(a)) * sqrt(abs(c));
	tmp = 0.0;
	if ((sign(c) * abs(a)) == a)
		tmp = sqrt((abs(b_2) - t_0)) * sqrt((abs(b_2) + t_0));
	else
		tmp = hypot(b_2, t_0);
	end
	t_1 = tmp;
	tmp_2 = 0.0;
	if (b_2 < 0.0)
		tmp_2 = c / (t_1 - b_2);
	else
		tmp_2 = (b_2 + t_1) / -a;
	end
	tmp_3 = tmp_2;
end
code[a_, b$95$2_, c_] := Block[{t$95$0 = N[(N[Sqrt[N[Abs[a], $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[Abs[c], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = If[Equal[N[With[{TMP1 = Abs[a], TMP2 = Sign[c]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], a], N[(N[Sqrt[N[(N[Abs[b$95$2], $MachinePrecision] - t$95$0), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(N[Abs[b$95$2], $MachinePrecision] + t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Sqrt[b$95$2 ^ 2 + t$95$0 ^ 2], $MachinePrecision]]}, If[Less[b$95$2, 0.0], N[(c / N[(t$95$1 - b$95$2), $MachinePrecision]), $MachinePrecision], N[(N[(b$95$2 + t$95$1), $MachinePrecision] / (-a)), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt{\left|a\right|} \cdot \sqrt{\left|c\right|}\\
t_1 := \begin{array}{l}
\mathbf{if}\;\mathsf{copysign}\left(a, c\right) = a:\\
\;\;\;\;\sqrt{\left|b\_2\right| - t\_0} \cdot \sqrt{\left|b\_2\right| + t\_0}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(b\_2, t\_0\right)\\


\end{array}\\
\mathbf{if}\;b\_2 < 0:\\
\;\;\;\;\frac{c}{t\_1 - b\_2}\\

\mathbf{else}:\\
\;\;\;\;\frac{b\_2 + t\_1}{-a}\\


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2025153 
(FPCore (a b_2 c)
  :name "quad2m (problem 3.2.1, negative)"
  :precision binary64
  :herbie-expected 10

  :alt
  (! :herbie-platform c (let ((sqtD (let ((x (* (sqrt (fabs a)) (sqrt (fabs c))))) (if (== (copysign a c) a) (* (sqrt (- (fabs b_2) x)) (sqrt (+ (fabs b_2) x))) (hypot b_2 x))))) (if (< b_2 0) (/ c (- sqtD b_2)) (/ (+ b_2 sqtD) (- a)))))

  (/ (- (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))