
(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(4.0 * Float64(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[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 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(4.0 * Float64(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[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -4e-145)
(/ (- c) b)
(if (<= b 2e+97)
(/ (- (- b) (sqrt (- (* b b) (* 4.0 (* c a))))) (* a 2.0))
(/ (- b) a))))
double code(double a, double b, double c) {
double tmp;
if (b <= -4e-145) {
tmp = -c / b;
} else if (b <= 2e+97) {
tmp = (-b - sqrt(((b * b) - (4.0 * (c * a))))) / (a * 2.0);
} else {
tmp = -b / 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) :: tmp
if (b <= (-4d-145)) then
tmp = -c / b
else if (b <= 2d+97) then
tmp = (-b - sqrt(((b * b) - (4.0d0 * (c * a))))) / (a * 2.0d0)
else
tmp = -b / a
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -4e-145) {
tmp = -c / b;
} else if (b <= 2e+97) {
tmp = (-b - Math.sqrt(((b * b) - (4.0 * (c * a))))) / (a * 2.0);
} else {
tmp = -b / a;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -4e-145: tmp = -c / b elif b <= 2e+97: tmp = (-b - math.sqrt(((b * b) - (4.0 * (c * a))))) / (a * 2.0) else: tmp = -b / a return tmp
function code(a, b, c) tmp = 0.0 if (b <= -4e-145) tmp = Float64(Float64(-c) / b); elseif (b <= 2e+97) tmp = Float64(Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(c * a))))) / Float64(a * 2.0)); else tmp = Float64(Float64(-b) / a); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -4e-145) tmp = -c / b; elseif (b <= 2e+97) tmp = (-b - sqrt(((b * b) - (4.0 * (c * a))))) / (a * 2.0); else tmp = -b / a; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -4e-145], N[((-c) / b), $MachinePrecision], If[LessEqual[b, 2e+97], N[(N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-b) / a), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -4 \cdot 10^{-145}:\\
\;\;\;\;\frac{-c}{b}\\
\mathbf{elif}\;b \leq 2 \cdot 10^{+97}:\\
\;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(c \cdot a\right)}}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\
\end{array}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -2.65e-149)
(/ (- c) b)
(if (<= b 3.5e-68)
(* -0.5 (/ (+ b (sqrt (* (* c a) -4.0))) a))
(- (/ c b) (/ b a)))))
double code(double a, double b, double c) {
double tmp;
if (b <= -2.65e-149) {
tmp = -c / b;
} else if (b <= 3.5e-68) {
tmp = -0.5 * ((b + sqrt(((c * a) * -4.0))) / a);
} else {
tmp = (c / b) - (b / 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) :: tmp
if (b <= (-2.65d-149)) then
tmp = -c / b
else if (b <= 3.5d-68) then
tmp = (-0.5d0) * ((b + sqrt(((c * a) * (-4.0d0)))) / a)
else
tmp = (c / b) - (b / a)
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -2.65e-149) {
tmp = -c / b;
} else if (b <= 3.5e-68) {
tmp = -0.5 * ((b + Math.sqrt(((c * a) * -4.0))) / a);
} else {
tmp = (c / b) - (b / a);
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2.65e-149: tmp = -c / b elif b <= 3.5e-68: tmp = -0.5 * ((b + math.sqrt(((c * a) * -4.0))) / a) else: tmp = (c / b) - (b / a) return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2.65e-149) tmp = Float64(Float64(-c) / b); elseif (b <= 3.5e-68) tmp = Float64(-0.5 * Float64(Float64(b + sqrt(Float64(Float64(c * a) * -4.0))) / a)); else tmp = Float64(Float64(c / b) - Float64(b / a)); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2.65e-149) tmp = -c / b; elseif (b <= 3.5e-68) tmp = -0.5 * ((b + sqrt(((c * a) * -4.0))) / a); else tmp = (c / b) - (b / a); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2.65e-149], N[((-c) / b), $MachinePrecision], If[LessEqual[b, 3.5e-68], N[(-0.5 * N[(N[(b + N[Sqrt[N[(N[(c * a), $MachinePrecision] * -4.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2.65 \cdot 10^{-149}:\\
\;\;\;\;\frac{-c}{b}\\
\mathbf{elif}\;b \leq 3.5 \cdot 10^{-68}:\\
\;\;\;\;-0.5 \cdot \frac{b + \sqrt{\left(c \cdot a\right) \cdot -4}}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -1e-310) (/ (- c) b) (- (/ c b) (/ b a))))
double code(double a, double b, double c) {
double tmp;
if (b <= -1e-310) {
tmp = -c / b;
} else {
tmp = (c / b) - (b / 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) :: tmp
if (b <= (-1d-310)) then
tmp = -c / b
else
tmp = (c / b) - (b / a)
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -1e-310) {
tmp = -c / b;
} else {
tmp = (c / b) - (b / a);
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -1e-310: tmp = -c / b else: tmp = (c / b) - (b / a) return tmp
function code(a, b, c) tmp = 0.0 if (b <= -1e-310) tmp = Float64(Float64(-c) / b); else tmp = Float64(Float64(c / b) - Float64(b / a)); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -1e-310) tmp = -c / b; else tmp = (c / b) - (b / a); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -1e-310], N[((-c) / b), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -1 \cdot 10^{-310}:\\
\;\;\;\;\frac{-c}{b}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -2.45e+45) (/ c b) (/ (- b) a)))
double code(double a, double b, double c) {
double tmp;
if (b <= -2.45e+45) {
tmp = c / b;
} else {
tmp = -b / 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) :: tmp
if (b <= (-2.45d+45)) then
tmp = c / b
else
tmp = -b / a
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -2.45e+45) {
tmp = c / b;
} else {
tmp = -b / a;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2.45e+45: tmp = c / b else: tmp = -b / a return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2.45e+45) tmp = Float64(c / b); else tmp = Float64(Float64(-b) / a); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2.45e+45) tmp = c / b; else tmp = -b / a; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2.45e+45], N[(c / b), $MachinePrecision], N[((-b) / a), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2.45 \cdot 10^{+45}:\\
\;\;\;\;\frac{c}{b}\\
\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\
\end{array}
\end{array}
(FPCore (a b c) :precision binary64 (if (<= b -1.6e-308) (/ (- c) b) (/ (- b) a)))
double code(double a, double b, double c) {
double tmp;
if (b <= -1.6e-308) {
tmp = -c / b;
} else {
tmp = -b / 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) :: tmp
if (b <= (-1.6d-308)) then
tmp = -c / b
else
tmp = -b / a
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -1.6e-308) {
tmp = -c / b;
} else {
tmp = -b / a;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -1.6e-308: tmp = -c / b else: tmp = -b / a return tmp
function code(a, b, c) tmp = 0.0 if (b <= -1.6e-308) tmp = Float64(Float64(-c) / b); else tmp = Float64(Float64(-b) / a); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -1.6e-308) tmp = -c / b; else tmp = -b / a; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -1.6e-308], N[((-c) / b), $MachinePrecision], N[((-b) / a), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.6 \cdot 10^{-308}:\\
\;\;\;\;\frac{-c}{b}\\
\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\
\end{array}
\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 (fabs (/ b 2.0)))
(t_1 (* (sqrt (fabs a)) (sqrt (fabs c))))
(t_2
(if (== (copysign a c) a)
(* (sqrt (- t_0 t_1)) (sqrt (+ t_0 t_1)))
(hypot (/ b 2.0) t_1))))
(if (< b 0.0) (/ c (- t_2 (/ b 2.0))) (/ (+ (/ b 2.0) t_2) (- a)))))
double code(double a, double b, double c) {
double t_0 = fabs((b / 2.0));
double t_1 = sqrt(fabs(a)) * sqrt(fabs(c));
double tmp;
if (copysign(a, c) == a) {
tmp = sqrt((t_0 - t_1)) * sqrt((t_0 + t_1));
} else {
tmp = hypot((b / 2.0), t_1);
}
double t_2 = tmp;
double tmp_1;
if (b < 0.0) {
tmp_1 = c / (t_2 - (b / 2.0));
} else {
tmp_1 = ((b / 2.0) + t_2) / -a;
}
return tmp_1;
}
public static double code(double a, double b, double c) {
double t_0 = Math.abs((b / 2.0));
double t_1 = Math.sqrt(Math.abs(a)) * Math.sqrt(Math.abs(c));
double tmp;
if (Math.copySign(a, c) == a) {
tmp = Math.sqrt((t_0 - t_1)) * Math.sqrt((t_0 + t_1));
} else {
tmp = Math.hypot((b / 2.0), t_1);
}
double t_2 = tmp;
double tmp_1;
if (b < 0.0) {
tmp_1 = c / (t_2 - (b / 2.0));
} else {
tmp_1 = ((b / 2.0) + t_2) / -a;
}
return tmp_1;
}
def code(a, b, c): t_0 = math.fabs((b / 2.0)) t_1 = math.sqrt(math.fabs(a)) * math.sqrt(math.fabs(c)) tmp = 0 if math.copysign(a, c) == a: tmp = math.sqrt((t_0 - t_1)) * math.sqrt((t_0 + t_1)) else: tmp = math.hypot((b / 2.0), t_1) t_2 = tmp tmp_1 = 0 if b < 0.0: tmp_1 = c / (t_2 - (b / 2.0)) else: tmp_1 = ((b / 2.0) + t_2) / -a return tmp_1
function code(a, b, c) t_0 = abs(Float64(b / 2.0)) t_1 = Float64(sqrt(abs(a)) * sqrt(abs(c))) tmp = 0.0 if (copysign(a, c) == a) tmp = Float64(sqrt(Float64(t_0 - t_1)) * sqrt(Float64(t_0 + t_1))); else tmp = hypot(Float64(b / 2.0), t_1); end t_2 = tmp tmp_1 = 0.0 if (b < 0.0) tmp_1 = Float64(c / Float64(t_2 - Float64(b / 2.0))); else tmp_1 = Float64(Float64(Float64(b / 2.0) + t_2) / Float64(-a)); end return tmp_1 end
function tmp_3 = code(a, b, c) t_0 = abs((b / 2.0)); t_1 = sqrt(abs(a)) * sqrt(abs(c)); tmp = 0.0; if ((sign(c) * abs(a)) == a) tmp = sqrt((t_0 - t_1)) * sqrt((t_0 + t_1)); else tmp = hypot((b / 2.0), t_1); end t_2 = tmp; tmp_2 = 0.0; if (b < 0.0) tmp_2 = c / (t_2 - (b / 2.0)); else tmp_2 = ((b / 2.0) + t_2) / -a; end tmp_3 = tmp_2; end
code[a_, b_, c_] := Block[{t$95$0 = N[Abs[N[(b / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[Sqrt[N[Abs[a], $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[Abs[c], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = If[Equal[N[With[{TMP1 = Abs[a], TMP2 = Sign[c]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], a], N[(N[Sqrt[N[(t$95$0 - t$95$1), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(t$95$0 + t$95$1), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Sqrt[N[(b / 2.0), $MachinePrecision] ^ 2 + t$95$1 ^ 2], $MachinePrecision]]}, If[Less[b, 0.0], N[(c / N[(t$95$2 - N[(b / 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(b / 2.0), $MachinePrecision] + t$95$2), $MachinePrecision] / (-a)), $MachinePrecision]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left|\frac{b}{2}\right|\\
t_1 := \sqrt{\left|a\right|} \cdot \sqrt{\left|c\right|}\\
t_2 := \begin{array}{l}
\mathbf{if}\;\mathsf{copysign}\left(a, c\right) = a:\\
\;\;\;\;\sqrt{t_0 - t_1} \cdot \sqrt{t_0 + t_1}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(\frac{b}{2}, t_1\right)\\
\end{array}\\
\mathbf{if}\;b < 0:\\
\;\;\;\;\frac{c}{t_2 - \frac{b}{2}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{b}{2} + t_2}{-a}\\
\end{array}
\end{array}
herbie shell --seed 2024008
(FPCore (a b c)
:name "quadm (p42, negative)"
:precision binary64
:herbie-expected 10
:herbie-target
(if (< b 0.0) (/ c (- (if (== (copysign a c) a) (* (sqrt (- (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c))))) (sqrt (+ (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (hypot (/ b 2.0) (* (sqrt (fabs a)) (sqrt (fabs c))))) (/ b 2.0))) (/ (+ (/ b 2.0) (if (== (copysign a c) a) (* (sqrt (- (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c))))) (sqrt (+ (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (hypot (/ b 2.0) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (- a)))
(/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))