
(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 -4.1e+160)
(- (/ c b) (/ b a))
(if (<= b 1.15e-72)
(/ (- (sqrt (fma b b (* c (* a -4.0)))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -4.1e+160) {
tmp = (c / b) - (b / a);
} else if (b <= 1.15e-72) {
tmp = (sqrt(fma(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 <= -4.1e+160) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 1.15e-72) tmp = Float64(Float64(sqrt(fma(b, b, Float64(c * Float64(a * -4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, -4.1e+160], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 1.15e-72], N[(N[(N[Sqrt[N[(b * b + 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 -4.1 \cdot 10^{+160}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 1.15 \cdot 10^{-72}:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -4.1e+160)
(- (/ c b) (/ b a))
(if (<= b 2.3e-71)
(/ (- (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 <= -4.1e+160) {
tmp = (c / b) - (b / a);
} else if (b <= 2.3e-71) {
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 <= -4.1e+160) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 2.3e-71) 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, -4.1e+160], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2.3e-71], 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 -4.1 \cdot 10^{+160}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 2.3 \cdot 10^{-71}:\\
\;\;\;\;\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 -4.1e+160)
(- (/ c b) (/ b a))
(if (<= b 1.05e-69)
(/ (- (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 <= -4.1e+160) {
tmp = (c / b) - (b / a);
} else if (b <= 1.05e-69) {
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 <= (-4.1d+160)) then
tmp = (c / b) - (b / a)
else if (b <= 1.05d-69) 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 <= -4.1e+160) {
tmp = (c / b) - (b / a);
} else if (b <= 1.05e-69) {
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 <= -4.1e+160: tmp = (c / b) - (b / a) elif b <= 1.05e-69: 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 <= -4.1e+160) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 1.05e-69) 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 <= -4.1e+160) tmp = (c / b) - (b / a); elseif (b <= 1.05e-69) 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, -4.1e+160], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 1.05e-69], 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 -4.1 \cdot 10^{+160}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 1.05 \cdot 10^{-69}:\\
\;\;\;\;\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 -1.15e-118) (- (/ c b) (/ b a)) (if (<= b 2e-72) (* (/ 0.5 a) (+ b (sqrt (* c (* a -4.0))))) (/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -1.15e-118) {
tmp = (c / b) - (b / a);
} else if (b <= 2e-72) {
tmp = (0.5 / a) * (b + sqrt((c * (a * -4.0))));
} 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 <= (-1.15d-118)) then
tmp = (c / b) - (b / a)
else if (b <= 2d-72) then
tmp = (0.5d0 / a) * (b + sqrt((c * (a * (-4.0d0)))))
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -1.15e-118) {
tmp = (c / b) - (b / a);
} else if (b <= 2e-72) {
tmp = (0.5 / a) * (b + Math.sqrt((c * (a * -4.0))));
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -1.15e-118: tmp = (c / b) - (b / a) elif b <= 2e-72: tmp = (0.5 / a) * (b + math.sqrt((c * (a * -4.0)))) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -1.15e-118) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 2e-72) tmp = Float64(Float64(0.5 / a) * Float64(b + sqrt(Float64(c * Float64(a * -4.0))))); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -1.15e-118) tmp = (c / b) - (b / a); elseif (b <= 2e-72) tmp = (0.5 / a) * (b + sqrt((c * (a * -4.0)))); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -1.15e-118], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 2e-72], N[(N[(0.5 / a), $MachinePrecision] * N[(b + N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.15 \cdot 10^{-118}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 2 \cdot 10^{-72}:\\
\;\;\;\;\frac{0.5}{a} \cdot \left(b + \sqrt{c \cdot \left(a \cdot -4\right)}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -1.15e-118)
(- (/ c b) (/ b a))
(if (<= b 4.1e-73)
(/ (- (sqrt (* c (* a -4.0))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -1.15e-118) {
tmp = (c / b) - (b / a);
} else if (b <= 4.1e-73) {
tmp = (sqrt((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 <= (-1.15d-118)) then
tmp = (c / b) - (b / a)
else if (b <= 4.1d-73) then
tmp = (sqrt((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 <= -1.15e-118) {
tmp = (c / b) - (b / a);
} else if (b <= 4.1e-73) {
tmp = (Math.sqrt((c * (a * -4.0))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -1.15e-118: tmp = (c / b) - (b / a) elif b <= 4.1e-73: tmp = (math.sqrt((c * (a * -4.0))) - b) / (a * 2.0) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -1.15e-118) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 4.1e-73) tmp = Float64(Float64(sqrt(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 <= -1.15e-118) tmp = (c / b) - (b / a); elseif (b <= 4.1e-73) tmp = (sqrt((c * (a * -4.0))) - b) / (a * 2.0); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -1.15e-118], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 4.1e-73], N[(N[(N[Sqrt[N[(c * N[(a * -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 -1.15 \cdot 10^{-118}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 4.1 \cdot 10^{-73}:\\
\;\;\;\;\frac{\sqrt{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 -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 -2e-310) (/ (- b) a) 0.0))
double code(double a, double b, double c) {
double tmp;
if (b <= -2e-310) {
tmp = -b / a;
} else {
tmp = 0.0;
}
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 = -b / a
else
tmp = 0.0d0
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -2e-310) {
tmp = -b / a;
} else {
tmp = 0.0;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2e-310: tmp = -b / a else: tmp = 0.0 return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2e-310) tmp = Float64(Float64(-b) / a); else tmp = 0.0; end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2e-310) tmp = -b / a; else tmp = 0.0; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2e-310], N[((-b) / a), $MachinePrecision], 0.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2 \cdot 10^{-310}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;0\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b 1.15e-285) (/ (- b) a) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 1.15e-285) {
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 <= 1.15d-285) 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 <= 1.15e-285) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 1.15e-285: tmp = -b / a else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= 1.15e-285) 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 <= 1.15e-285) tmp = -b / a; else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 1.15e-285], N[((-b) / a), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 1.15 \cdot 10^{-285}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 0.0)
double code(double a, double b, double c) {
return 0.0;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = 0.0d0
end function
public static double code(double a, double b, double c) {
return 0.0;
}
def code(a, b, c): return 0.0
function code(a, b, c) return 0.0 end
function tmp = code(a, b, c) tmp = 0.0; end
code[a_, b_, c_] := 0.0
\begin{array}{l}
\\
0
\end{array}
herbie shell --seed 2024006
(FPCore (a b c)
:name "Quadratic roots, full range"
:precision binary64
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))