
(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 9 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 -2e+151)
(- (/ c b) (/ b a))
(if (<= b 6.5e-144)
(/ (- (sqrt (fma a (* c -4.0) (* b b))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -2e+151) {
tmp = (c / b) - (b / a);
} else if (b <= 6.5e-144) {
tmp = (sqrt(fma(a, (c * -4.0), (b * b))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= -2e+151) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 6.5e-144) tmp = Float64(Float64(sqrt(fma(a, Float64(c * -4.0), Float64(b * b))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, -2e+151], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 6.5e-144], N[(N[(N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2 \cdot 10^{+151}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 6.5 \cdot 10^{-144}:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -2e+151)
(- (/ c b) (/ b a))
(if (<= b 6.5e-144)
(/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -2e+151) {
tmp = (c / b) - (b / a);
} else if (b <= 6.5e-144) {
tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} 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 <= (-2d+151)) then
tmp = (c / b) - (b / a)
else if (b <= 6.5d-144) then
tmp = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -2e+151) {
tmp = (c / b) - (b / a);
} else if (b <= 6.5e-144) {
tmp = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2e+151: tmp = (c / b) - (b / a) elif b <= 6.5e-144: tmp = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2e+151) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 6.5e-144) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2e+151) tmp = (c / b) - (b / a); elseif (b <= 6.5e-144) tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2e+151], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 6.5e-144], 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[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2 \cdot 10^{+151}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 6.5 \cdot 10^{-144}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -1.22e-29)
(- (/ c b) (/ b a))
(if (<= b 6.5e-144)
(/ (- (sqrt (* a (* c -4.0))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -1.22e-29) {
tmp = (c / b) - (b / a);
} else if (b <= 6.5e-144) {
tmp = (sqrt((a * (c * -4.0))) - b) / (a * 2.0);
} 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 <= (-1.22d-29)) then
tmp = (c / b) - (b / a)
else if (b <= 6.5d-144) then
tmp = (sqrt((a * (c * (-4.0d0)))) - b) / (a * 2.0d0)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -1.22e-29) {
tmp = (c / b) - (b / a);
} else if (b <= 6.5e-144) {
tmp = (Math.sqrt((a * (c * -4.0))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -1.22e-29: tmp = (c / b) - (b / a) elif b <= 6.5e-144: tmp = (math.sqrt((a * (c * -4.0))) - b) / (a * 2.0) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -1.22e-29) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 6.5e-144) tmp = Float64(Float64(sqrt(Float64(a * Float64(c * -4.0))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -1.22e-29) tmp = (c / b) - (b / a); elseif (b <= 6.5e-144) tmp = (sqrt((a * (c * -4.0))) - b) / (a * 2.0); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -1.22e-29], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 6.5e-144], N[(N[(N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.22 \cdot 10^{-29}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 6.5 \cdot 10^{-144}:\\
\;\;\;\;\frac{\sqrt{a \cdot \left(c \cdot -4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -7.2e-169) (- (/ c b) (/ b a)) (if (<= b 3.4e-156) (* 0.5 (sqrt (* (* c -4.0) (/ 1.0 a)))) (/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -7.2e-169) {
tmp = (c / b) - (b / a);
} else if (b <= 3.4e-156) {
tmp = 0.5 * sqrt(((c * -4.0) * (1.0 / 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 <= (-7.2d-169)) then
tmp = (c / b) - (b / a)
else if (b <= 3.4d-156) then
tmp = 0.5d0 * sqrt(((c * (-4.0d0)) * (1.0d0 / 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 <= -7.2e-169) {
tmp = (c / b) - (b / a);
} else if (b <= 3.4e-156) {
tmp = 0.5 * Math.sqrt(((c * -4.0) * (1.0 / a)));
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -7.2e-169: tmp = (c / b) - (b / a) elif b <= 3.4e-156: tmp = 0.5 * math.sqrt(((c * -4.0) * (1.0 / a))) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -7.2e-169) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 3.4e-156) tmp = Float64(0.5 * sqrt(Float64(Float64(c * -4.0) * Float64(1.0 / a)))); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -7.2e-169) tmp = (c / b) - (b / a); elseif (b <= 3.4e-156) tmp = 0.5 * sqrt(((c * -4.0) * (1.0 / a))); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -7.2e-169], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 3.4e-156], N[(0.5 * N[Sqrt[N[(N[(c * -4.0), $MachinePrecision] * N[(1.0 / a), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -7.2 \cdot 10^{-169}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 3.4 \cdot 10^{-156}:\\
\;\;\;\;0.5 \cdot \sqrt{\left(c \cdot -4\right) \cdot \frac{1}{a}}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -2.15e-78) (- (/ c b) (/ b a)) (if (<= b 6.5e-144) (* 0.5 (/ (sqrt (* a (* c -4.0))) a)) (/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -2.15e-78) {
tmp = (c / b) - (b / a);
} else if (b <= 6.5e-144) {
tmp = 0.5 * (sqrt((a * (c * -4.0))) / 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 <= (-2.15d-78)) then
tmp = (c / b) - (b / a)
else if (b <= 6.5d-144) then
tmp = 0.5d0 * (sqrt((a * (c * (-4.0d0)))) / 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 <= -2.15e-78) {
tmp = (c / b) - (b / a);
} else if (b <= 6.5e-144) {
tmp = 0.5 * (Math.sqrt((a * (c * -4.0))) / a);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2.15e-78: tmp = (c / b) - (b / a) elif b <= 6.5e-144: tmp = 0.5 * (math.sqrt((a * (c * -4.0))) / a) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2.15e-78) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 6.5e-144) tmp = Float64(0.5 * Float64(sqrt(Float64(a * Float64(c * -4.0))) / a)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2.15e-78) tmp = (c / b) - (b / a); elseif (b <= 6.5e-144) tmp = 0.5 * (sqrt((a * (c * -4.0))) / a); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2.15e-78], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 6.5e-144], N[(0.5 * N[(N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2.15 \cdot 10^{-78}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 6.5 \cdot 10^{-144}:\\
\;\;\;\;0.5 \cdot \frac{\sqrt{a \cdot \left(c \cdot -4\right)}}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -2e-310) (- (/ c b) (/ b a)) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= -2e-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 <= (-2d-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 <= -2e-310) {
tmp = (c / b) - (b / a);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2e-310: tmp = (c / b) - (b / a) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2e-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 <= -2e-310) tmp = (c / b) - (b / a); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2e-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 -2 \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 3e-309) (/ (- b) a) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 3e-309) {
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 <= 3d-309) 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 <= 3e-309) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 3e-309: tmp = -b / a else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= 3e-309) 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 <= 3e-309) tmp = -b / a; else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 3e-309], N[((-b) / a), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 3 \cdot 10^{-309}:\\
\;\;\;\;\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(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 (/ 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}
herbie shell --seed 2023350
(FPCore (a b c)
:name "Quadratic roots, full range"
:precision binary64
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))