
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (-b + sqrt(((b * b) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (-b + sqrt(((b * b) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -3e+135)
(- (/ c b) (/ b a))
(if (<= b 6.8e-7)
(/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0))
(/ 1.0 (- (/ a b) (/ b c))))))
double code(double a, double b, double c) {
double tmp;
if (b <= -3e+135) {
tmp = (c / b) - (b / a);
} else if (b <= 6.8e-7) {
tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = 1.0 / ((a / b) - (b / c));
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-3d+135)) then
tmp = (c / b) - (b / a)
else if (b <= 6.8d-7) then
tmp = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
else
tmp = 1.0d0 / ((a / b) - (b / c))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -3e+135) {
tmp = (c / b) - (b / a);
} else if (b <= 6.8e-7) {
tmp = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = 1.0 / ((a / b) - (b / c));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -3e+135: tmp = (c / b) - (b / a) elif b <= 6.8e-7: tmp = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) else: tmp = 1.0 / ((a / b) - (b / c)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= -3e+135) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 6.8e-7) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(1.0 / Float64(Float64(a / b) - Float64(b / c))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -3e+135) tmp = (c / b) - (b / a); elseif (b <= 6.8e-7) tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); else tmp = 1.0 / ((a / b) - (b / c)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -3e+135], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 6.8e-7], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[(a / b), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -3 \cdot 10^{+135}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 6.8 \cdot 10^{-7}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\frac{a}{b} - \frac{b}{c}}\\
\end{array}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -4.4e-37)
(- (/ c b) (/ b a))
(if (or (<= b 4.5e-140) (and (not (<= b 1.9e-47)) (<= b 6.8e-7)))
(/ (- (sqrt (* a (* c -4.0))) b) (* a 2.0))
(/ 1.0 (- (/ a b) (/ b c))))))
double code(double a, double b, double c) {
double tmp;
if (b <= -4.4e-37) {
tmp = (c / b) - (b / a);
} else if ((b <= 4.5e-140) || (!(b <= 1.9e-47) && (b <= 6.8e-7))) {
tmp = (sqrt((a * (c * -4.0))) - b) / (a * 2.0);
} else {
tmp = 1.0 / ((a / b) - (b / c));
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-4.4d-37)) then
tmp = (c / b) - (b / a)
else if ((b <= 4.5d-140) .or. (.not. (b <= 1.9d-47)) .and. (b <= 6.8d-7)) then
tmp = (sqrt((a * (c * (-4.0d0)))) - b) / (a * 2.0d0)
else
tmp = 1.0d0 / ((a / b) - (b / c))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -4.4e-37) {
tmp = (c / b) - (b / a);
} else if ((b <= 4.5e-140) || (!(b <= 1.9e-47) && (b <= 6.8e-7))) {
tmp = (Math.sqrt((a * (c * -4.0))) - b) / (a * 2.0);
} else {
tmp = 1.0 / ((a / b) - (b / c));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -4.4e-37: tmp = (c / b) - (b / a) elif (b <= 4.5e-140) or (not (b <= 1.9e-47) and (b <= 6.8e-7)): tmp = (math.sqrt((a * (c * -4.0))) - b) / (a * 2.0) else: tmp = 1.0 / ((a / b) - (b / c)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= -4.4e-37) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif ((b <= 4.5e-140) || (!(b <= 1.9e-47) && (b <= 6.8e-7))) tmp = Float64(Float64(sqrt(Float64(a * Float64(c * -4.0))) - b) / Float64(a * 2.0)); else tmp = Float64(1.0 / Float64(Float64(a / b) - Float64(b / c))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -4.4e-37) tmp = (c / b) - (b / a); elseif ((b <= 4.5e-140) || (~((b <= 1.9e-47)) && (b <= 6.8e-7))) tmp = (sqrt((a * (c * -4.0))) - b) / (a * 2.0); else tmp = 1.0 / ((a / b) - (b / c)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -4.4e-37], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[Or[LessEqual[b, 4.5e-140], And[N[Not[LessEqual[b, 1.9e-47]], $MachinePrecision], LessEqual[b, 6.8e-7]]], N[(N[(N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[(a / b), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -4.4 \cdot 10^{-37}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 4.5 \cdot 10^{-140} \lor \neg \left(b \leq 1.9 \cdot 10^{-47}\right) \land b \leq 6.8 \cdot 10^{-7}:\\
\;\;\;\;\frac{\sqrt{a \cdot \left(c \cdot -4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\frac{a}{b} - \frac{b}{c}}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -2.25e-291) (- (/ c b) (/ b a)) (/ 1.0 (- (/ a b) (/ b c)))))
double code(double a, double b, double c) {
double tmp;
if (b <= -2.25e-291) {
tmp = (c / b) - (b / a);
} else {
tmp = 1.0 / ((a / b) - (b / c));
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-2.25d-291)) then
tmp = (c / b) - (b / a)
else
tmp = 1.0d0 / ((a / b) - (b / c))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -2.25e-291) {
tmp = (c / b) - (b / a);
} else {
tmp = 1.0 / ((a / b) - (b / c));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2.25e-291: tmp = (c / b) - (b / a) else: tmp = 1.0 / ((a / b) - (b / c)) return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2.25e-291) tmp = Float64(Float64(c / b) - Float64(b / a)); else tmp = Float64(1.0 / Float64(Float64(a / b) - Float64(b / c))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2.25e-291) tmp = (c / b) - (b / a); else tmp = 1.0 / ((a / b) - (b / c)); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2.25e-291], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[(a / b), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2.25 \cdot 10^{-291}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\frac{a}{b} - \frac{b}{c}}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -5e-310) (- (/ c b) (/ b a)) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= -5e-310) {
tmp = (c / b) - (b / a);
} else {
tmp = -c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-5d-310)) then
tmp = (c / b) - (b / a)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -5e-310) {
tmp = (c / b) - (b / a);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -5e-310: tmp = (c / b) - (b / a) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -5e-310) tmp = Float64(Float64(c / b) - Float64(b / a)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -5e-310) tmp = (c / b) - (b / a); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -5e-310], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b 2.8e+29) (/ (- b) a) (/ c b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 2.8e+29) {
tmp = -b / a;
} else {
tmp = c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= 2.8d+29) then
tmp = -b / a
else
tmp = c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 2.8e+29) {
tmp = -b / a;
} else {
tmp = c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 2.8e+29: tmp = -b / a else: tmp = c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= 2.8e+29) tmp = Float64(Float64(-b) / a); else tmp = Float64(c / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 2.8e+29) tmp = -b / a; else tmp = c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 2.8e+29], N[((-b) / a), $MachinePrecision], N[(c / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 2.8 \cdot 10^{+29}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -5e-310) (/ (- b) a) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= -5e-310) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-5d-310)) then
tmp = -b / a
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -5e-310) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -5e-310: tmp = -b / a else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -5e-310) tmp = Float64(Float64(-b) / a); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -5e-310) tmp = -b / a; else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -5e-310], N[((-b) / a), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (/ b a))
double code(double a, double b, double c) {
return b / a;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = b / a
end function
public static double code(double a, double b, double c) {
return b / a;
}
def code(a, b, c): return b / a
function code(a, b, c) return Float64(b / a) end
function tmp = code(a, b, c) tmp = b / a; end
code[a_, b_, c_] := N[(b / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{b}{a}
\end{array}
(FPCore (a b c) :precision binary64 (/ c b))
double code(double a, double b, double c) {
return c / b;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = c / b
end function
public static double code(double a, double b, double c) {
return c / b;
}
def code(a, b, c): return c / b
function code(a, b, c) return Float64(c / b) end
function tmp = code(a, b, c) tmp = c / b; end
code[a_, b_, c_] := N[(c / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{b}
\end{array}
(FPCore (a b c)
:precision binary64
(let* ((t_0 (sqrt (- (* b b) (* (* 4.0 a) c)))))
(if (< b 0.0)
(/ (+ (- b) t_0) (* 2.0 a))
(/ c (* a (/ (- (- b) t_0) (* 2.0 a)))))))
double code(double a, double b, double c) {
double t_0 = sqrt(((b * b) - ((4.0 * a) * c)));
double tmp;
if (b < 0.0) {
tmp = (-b + t_0) / (2.0 * a);
} else {
tmp = c / (a * ((-b - t_0) / (2.0 * a)));
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: t_0
real(8) :: tmp
t_0 = sqrt(((b * b) - ((4.0d0 * a) * c)))
if (b < 0.0d0) then
tmp = (-b + t_0) / (2.0d0 * a)
else
tmp = c / (a * ((-b - t_0) / (2.0d0 * a)))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double t_0 = Math.sqrt(((b * b) - ((4.0 * a) * c)));
double tmp;
if (b < 0.0) {
tmp = (-b + t_0) / (2.0 * a);
} else {
tmp = c / (a * ((-b - t_0) / (2.0 * a)));
}
return tmp;
}
def code(a, b, c): t_0 = math.sqrt(((b * b) - ((4.0 * a) * c))) tmp = 0 if b < 0.0: tmp = (-b + t_0) / (2.0 * a) else: tmp = c / (a * ((-b - t_0) / (2.0 * a))) return tmp
function code(a, b, c) t_0 = sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c))) tmp = 0.0 if (b < 0.0) tmp = Float64(Float64(Float64(-b) + t_0) / Float64(2.0 * a)); else tmp = Float64(c / Float64(a * Float64(Float64(Float64(-b) - t_0) / Float64(2.0 * a)))); end return tmp end
function tmp_2 = code(a, b, c) t_0 = sqrt(((b * b) - ((4.0 * a) * c))); tmp = 0.0; if (b < 0.0) tmp = (-b + t_0) / (2.0 * a); else tmp = c / (a * ((-b - t_0) / (2.0 * a))); end tmp_2 = tmp; end
code[a_, b_, c_] := Block[{t$95$0 = N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[Less[b, 0.0], N[(N[((-b) + t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], N[(c / N[(a * N[(N[((-b) - t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\\
\mathbf{if}\;b < 0:\\
\;\;\;\;\frac{\left(-b\right) + t_0}{2 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{a \cdot \frac{\left(-b\right) - t_0}{2 \cdot a}}\\
\end{array}
\end{array}
herbie shell --seed 2023347
(FPCore (a b c)
:name "The quadratic formula (r1)"
:precision binary64
:herbie-target
(if (< b 0.0) (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)) (/ c (* a (/ (- (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))))
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))