
(FPCore (a b c) :precision binary64 (let* ((t_0 (sqrt (- (* b b) (* (* 4.0 a) c))))) (if (>= b 0.0) (/ (* 2.0 c) (- (- b) t_0)) (/ (+ (- 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 = (2.0 * c) / (-b - t_0);
} else {
tmp = (-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 = (2.0d0 * c) / (-b - t_0)
else
tmp = (-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 = (2.0 * c) / (-b - t_0);
} else {
tmp = (-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 = (2.0 * c) / (-b - t_0) else: tmp = (-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(2.0 * c) / Float64(Float64(-b) - t_0)); else tmp = 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 = (2.0 * c) / (-b - t_0); else tmp = (-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[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - t$95$0), $MachinePrecision]), $MachinePrecision], N[(N[((-b) + t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\\
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - t\_0}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + t\_0}{2 \cdot a}\\
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b c) :precision binary64 (let* ((t_0 (sqrt (- (* b b) (* (* 4.0 a) c))))) (if (>= b 0.0) (/ (* 2.0 c) (- (- b) t_0)) (/ (+ (- 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 = (2.0 * c) / (-b - t_0);
} else {
tmp = (-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 = (2.0d0 * c) / (-b - t_0)
else
tmp = (-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 = (2.0 * c) / (-b - t_0);
} else {
tmp = (-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 = (2.0 * c) / (-b - t_0) else: tmp = (-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(2.0 * c) / Float64(Float64(-b) - t_0)); else tmp = 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 = (2.0 * c) / (-b - t_0); else tmp = (-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[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - t$95$0), $MachinePrecision]), $MachinePrecision], N[(N[((-b) + t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\\
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - t\_0}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) + t\_0}{2 \cdot a}\\
\end{array}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -2e+149)
(if (>= b 0.0) (/ (* 2.0 c) (* b -2.0)) (- (/ c b) (/ b a)))
(if (<= b 2.9e+66)
(if (>= b 0.0)
(/ (* c -2.0) (+ b (sqrt (fma c (* a -4.0) (* b b)))))
(/ (- (sqrt (- (* b b) (* c (* 4.0 a)))) b) (* 2.0 a)))
(if (>= b 0.0)
(/ (* 2.0 c) (- (- b) (fma -2.0 (* a (/ c b)) b)))
(* b (+ (/ c (* b b)) (/ -1.0 a)))))))
double code(double a, double b, double c) {
double tmp_1;
if (b <= -2e+149) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = (2.0 * c) / (b * -2.0);
} else {
tmp_2 = (c / b) - (b / a);
}
tmp_1 = tmp_2;
} else if (b <= 2.9e+66) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = (c * -2.0) / (b + sqrt(fma(c, (a * -4.0), (b * b))));
} else {
tmp_3 = (sqrt(((b * b) - (c * (4.0 * a)))) - b) / (2.0 * a);
}
tmp_1 = tmp_3;
} else if (b >= 0.0) {
tmp_1 = (2.0 * c) / (-b - fma(-2.0, (a * (c / b)), b));
} else {
tmp_1 = b * ((c / (b * b)) + (-1.0 / a));
}
return tmp_1;
}
function code(a, b, c) tmp_1 = 0.0 if (b <= -2e+149) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(Float64(2.0 * c) / Float64(b * -2.0)); else tmp_2 = Float64(Float64(c / b) - Float64(b / a)); end tmp_1 = tmp_2; elseif (b <= 2.9e+66) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(Float64(c * -2.0) / Float64(b + sqrt(fma(c, Float64(a * -4.0), Float64(b * b))))); else tmp_3 = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(4.0 * a)))) - b) / Float64(2.0 * a)); end tmp_1 = tmp_3; elseif (b >= 0.0) tmp_1 = Float64(Float64(2.0 * c) / Float64(Float64(-b) - fma(-2.0, Float64(a * Float64(c / b)), b))); else tmp_1 = Float64(b * Float64(Float64(c / Float64(b * b)) + Float64(-1.0 / a))); end return tmp_1 end
code[a_, b_, c_] := If[LessEqual[b, -2e+149], If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[(b * -2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]], If[LessEqual[b, 2.9e+66], If[GreaterEqual[b, 0.0], N[(N[(c * -2.0), $MachinePrecision] / N[(b + N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(4.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]], If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - N[(-2.0 * N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(b * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2 \cdot 10^{+149}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{b \cdot -2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}\\
\mathbf{elif}\;b \leq 2.9 \cdot 10^{+66}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{c \cdot -2}{b + \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)} - b}{2 \cdot a}\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - \mathsf{fma}\left(-2, a \cdot \frac{c}{b}, b\right)}\\
\mathbf{else}:\\
\;\;\;\;b \cdot \left(\frac{c}{b \cdot b} + \frac{-1}{a}\right)\\
\end{array}
\end{array}
if b < -2.0000000000000001e149Initial program 33.5%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f64N/A
lower-*.f64N/A
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6497.5
Applied rewrites97.5%
Taylor expanded in b around inf
*-commutativeN/A
lower-*.f6497.5
Applied rewrites97.5%
Taylor expanded in c around 0
Applied rewrites98.3%
if -2.0000000000000001e149 < b < 2.89999999999999986e66Initial program 90.8%
Applied rewrites90.9%
if 2.89999999999999986e66 < b Initial program 51.8%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f64N/A
lower-*.f64N/A
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6451.8
Applied rewrites51.8%
Taylor expanded in a around 0
+-commutativeN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f6493.7
Applied rewrites93.7%
Final simplification92.7%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (sqrt (fma c (* a -4.0) (* b b)))))
(if (<= b -7.3e+84)
(if (>= b 0.0) (/ (* 2.0 c) (* b -2.0)) (- (/ c b) (/ b a)))
(if (<= b 1.9e-300)
(if (>= b 0.0) (/ (fma a (/ c (- b)) b) a) (* (/ 0.5 a) (- t_0 b)))
(if (<= b 2.9e+66)
(if (>= b 0.0) (/ (* c -2.0) (+ b t_0)) (/ (- (- b) b) (* 2.0 a)))
(if (>= b 0.0)
(/ (* 2.0 c) (- (- b) (fma -2.0 (* a (/ c b)) b)))
(* b (+ (/ c (* b b)) (/ -1.0 a)))))))))
double code(double a, double b, double c) {
double t_0 = sqrt(fma(c, (a * -4.0), (b * b)));
double tmp_1;
if (b <= -7.3e+84) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = (2.0 * c) / (b * -2.0);
} else {
tmp_2 = (c / b) - (b / a);
}
tmp_1 = tmp_2;
} else if (b <= 1.9e-300) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = fma(a, (c / -b), b) / a;
} else {
tmp_3 = (0.5 / a) * (t_0 - b);
}
tmp_1 = tmp_3;
} else if (b <= 2.9e+66) {
double tmp_4;
if (b >= 0.0) {
tmp_4 = (c * -2.0) / (b + t_0);
} else {
tmp_4 = (-b - b) / (2.0 * a);
}
tmp_1 = tmp_4;
} else if (b >= 0.0) {
tmp_1 = (2.0 * c) / (-b - fma(-2.0, (a * (c / b)), b));
} else {
tmp_1 = b * ((c / (b * b)) + (-1.0 / a));
}
return tmp_1;
}
function code(a, b, c) t_0 = sqrt(fma(c, Float64(a * -4.0), Float64(b * b))) tmp_1 = 0.0 if (b <= -7.3e+84) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(Float64(2.0 * c) / Float64(b * -2.0)); else tmp_2 = Float64(Float64(c / b) - Float64(b / a)); end tmp_1 = tmp_2; elseif (b <= 1.9e-300) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(fma(a, Float64(c / Float64(-b)), b) / a); else tmp_3 = Float64(Float64(0.5 / a) * Float64(t_0 - b)); end tmp_1 = tmp_3; elseif (b <= 2.9e+66) tmp_4 = 0.0 if (b >= 0.0) tmp_4 = Float64(Float64(c * -2.0) / Float64(b + t_0)); else tmp_4 = Float64(Float64(Float64(-b) - b) / Float64(2.0 * a)); end tmp_1 = tmp_4; elseif (b >= 0.0) tmp_1 = Float64(Float64(2.0 * c) / Float64(Float64(-b) - fma(-2.0, Float64(a * Float64(c / b)), b))); else tmp_1 = Float64(b * Float64(Float64(c / Float64(b * b)) + Float64(-1.0 / a))); end return tmp_1 end
code[a_, b_, c_] := Block[{t$95$0 = N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[b, -7.3e+84], If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[(b * -2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]], If[LessEqual[b, 1.9e-300], If[GreaterEqual[b, 0.0], N[(N[(a * N[(c / (-b)), $MachinePrecision] + b), $MachinePrecision] / a), $MachinePrecision], N[(N[(0.5 / a), $MachinePrecision] * N[(t$95$0 - b), $MachinePrecision]), $MachinePrecision]], If[LessEqual[b, 2.9e+66], If[GreaterEqual[b, 0.0], N[(N[(c * -2.0), $MachinePrecision] / N[(b + t$95$0), $MachinePrecision]), $MachinePrecision], N[(N[((-b) - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]], If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - N[(-2.0 * N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(b * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)}\\
\mathbf{if}\;b \leq -7.3 \cdot 10^{+84}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{b \cdot -2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}\\
\mathbf{elif}\;b \leq 1.9 \cdot 10^{-300}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{\mathsf{fma}\left(a, \frac{c}{-b}, b\right)}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{0.5}{a} \cdot \left(t\_0 - b\right)\\
\end{array}\\
\mathbf{elif}\;b \leq 2.9 \cdot 10^{+66}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{c \cdot -2}{b + t\_0}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) - b}{2 \cdot a}\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - \mathsf{fma}\left(-2, a \cdot \frac{c}{b}, b\right)}\\
\mathbf{else}:\\
\;\;\;\;b \cdot \left(\frac{c}{b \cdot b} + \frac{-1}{a}\right)\\
\end{array}
\end{array}
if b < -7.3e84Initial program 55.2%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f64N/A
lower-*.f64N/A
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6495.1
Applied rewrites95.1%
Taylor expanded in b around inf
*-commutativeN/A
lower-*.f6495.1
Applied rewrites95.1%
Taylor expanded in c around 0
Applied rewrites95.5%
if -7.3e84 < b < 1.90000000000000006e-300Initial program 86.5%
Applied rewrites86.5%
Taylor expanded in a around 0
lower-/.f64N/A
+-commutativeN/A
mul-1-negN/A
associate-/l*N/A
distribute-rgt-neg-inN/A
mul-1-negN/A
lower-fma.f64N/A
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6485.6
Applied rewrites85.6%
lift-/.f64N/A
clear-numN/A
associate-/r/N/A
lower-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f6485.4
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
Applied rewrites85.4%
if 1.90000000000000006e-300 < b < 2.89999999999999986e66Initial program 86.3%
Applied rewrites86.3%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f6486.3
Applied rewrites86.3%
if 2.89999999999999986e66 < b Initial program 58.7%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f64N/A
lower-*.f64N/A
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6458.7
Applied rewrites58.7%
Taylor expanded in a around 0
+-commutativeN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f6494.6
Applied rewrites94.6%
Final simplification90.3%
herbie shell --seed 2024227
(FPCore (a b c)
:name "jeff quadratic root 2"
:precision binary64
(if (>= b 0.0) (/ (* 2.0 c) (- (- b) (sqrt (- (* b b) (* (* 4.0 a) c))))) (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a))))