
(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)) (/ (* 2.0 c) (+ (- b) t_0)))))
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 = (2.0 * c) / (-b + t_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) :: 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 = (2.0d0 * c) / (-b + t_0)
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 = (2.0 * c) / (-b + t_0);
}
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 = (2.0 * c) / (-b + t_0) 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(Float64(2.0 * c) / Float64(Float64(-b) + t_0)); 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 = (2.0 * c) / (-b + t_0); 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[((-b) - t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) + t$95$0), $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{\left(-b\right) - t\_0}{2 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) + t\_0}\\
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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)) (/ (* 2.0 c) (+ (- b) t_0)))))
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 = (2.0 * c) / (-b + t_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) :: 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 = (2.0d0 * c) / (-b + t_0)
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 = (2.0 * c) / (-b + t_0);
}
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 = (2.0 * c) / (-b + t_0) 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(Float64(2.0 * c) / Float64(Float64(-b) + t_0)); 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 = (2.0 * c) / (-b + t_0); 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[((-b) - t$95$0), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) + t$95$0), $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{\left(-b\right) - t\_0}{2 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) + t\_0}\\
\end{array}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -1.15e+154)
(if (>= b 0.0) (/ (- b) a) (/ c (- b)))
(if (<= b 3e+129)
(if (>= b 0.0)
(/ (+ b (sqrt (fma -4.0 (* a c) (* b b)))) (* a -2.0))
(/ (* c 2.0) (- (sqrt (fma c (* a -4.0) (* b b))) b)))
(if (>= b 0.0) (- (/ c b) (/ b a)) (/ (* c 2.0) (- (- b) b))))))
double code(double a, double b, double c) {
double tmp_1;
if (b <= -1.15e+154) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = -b / a;
} else {
tmp_2 = c / -b;
}
tmp_1 = tmp_2;
} else if (b <= 3e+129) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = (b + sqrt(fma(-4.0, (a * c), (b * b)))) / (a * -2.0);
} else {
tmp_3 = (c * 2.0) / (sqrt(fma(c, (a * -4.0), (b * b))) - b);
}
tmp_1 = tmp_3;
} else if (b >= 0.0) {
tmp_1 = (c / b) - (b / a);
} else {
tmp_1 = (c * 2.0) / (-b - b);
}
return tmp_1;
}
function code(a, b, c) tmp_1 = 0.0 if (b <= -1.15e+154) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(Float64(-b) / a); else tmp_2 = Float64(c / Float64(-b)); end tmp_1 = tmp_2; elseif (b <= 3e+129) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(Float64(b + sqrt(fma(-4.0, Float64(a * c), Float64(b * b)))) / Float64(a * -2.0)); else tmp_3 = Float64(Float64(c * 2.0) / Float64(sqrt(fma(c, Float64(a * -4.0), Float64(b * b))) - b)); end tmp_1 = tmp_3; elseif (b >= 0.0) tmp_1 = Float64(Float64(c / b) - Float64(b / a)); else tmp_1 = Float64(Float64(c * 2.0) / Float64(Float64(-b) - b)); end return tmp_1 end
code[a_, b_, c_] := If[LessEqual[b, -1.15e+154], If[GreaterEqual[b, 0.0], N[((-b) / a), $MachinePrecision], N[(c / (-b)), $MachinePrecision]], If[LessEqual[b, 3e+129], If[GreaterEqual[b, 0.0], N[(N[(b + N[Sqrt[N[(-4.0 * N[(a * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * -2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c * 2.0), $MachinePrecision] / N[(N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision]], If[GreaterEqual[b, 0.0], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], N[(N[(c * 2.0), $MachinePrecision] / N[((-b) - b), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.15 \cdot 10^{+154}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{-b}\\
\end{array}\\
\mathbf{elif}\;b \leq 3 \cdot 10^{+129}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{b + \sqrt{\mathsf{fma}\left(-4, a \cdot c, b \cdot b\right)}}{a \cdot -2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot 2}{\sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)} - b}\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot 2}{\left(-b\right) - b}\\
\end{array}
\end{array}
if b < -1.15e154Initial program 22.9%
Taylor expanded in b around inf
*-commutativeN/A
lower-*.f6422.9
Applied rewrites22.9%
Taylor expanded in c around 0
mul-1-negN/A
distribute-neg-frac2N/A
neg-mul-1N/A
lower-/.f64N/A
neg-mul-1N/A
lower-neg.f642.4
Applied rewrites2.4%
Taylor expanded in b around inf
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f642.4
Applied rewrites2.4%
Taylor expanded in b around -inf
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6497.2
Applied rewrites97.2%
if -1.15e154 < b < 3.0000000000000003e129Initial program 87.0%
Applied rewrites86.9%
Applied rewrites87.0%
lift-fma.f64N/A
lift-*.f64N/A
associate-*r*N/A
*-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f6487.0
lift-*.f64N/A
*-commutativeN/A
lower-*.f6487.0
Applied rewrites87.0%
if 3.0000000000000003e129 < b Initial program 54.7%
Taylor expanded in c around 0
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f6496.6
Applied rewrites96.6%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f6496.6
Applied rewrites96.6%
Final simplification90.2%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (sqrt (fma -4.0 (* a c) (* b b)))))
(if (<= b -1.15e+154)
(if (>= b 0.0) (/ (- b) a) (/ c (- b)))
(if (<= b 3e+129)
(if (>= b 0.0) (/ (+ b t_0) (* a -2.0)) (/ (* c 2.0) (- t_0 b)))
(if (>= b 0.0) (- (/ c b) (/ b a)) (/ (* c 2.0) (- (- b) b)))))))
double code(double a, double b, double c) {
double t_0 = sqrt(fma(-4.0, (a * c), (b * b)));
double tmp_1;
if (b <= -1.15e+154) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = -b / a;
} else {
tmp_2 = c / -b;
}
tmp_1 = tmp_2;
} else if (b <= 3e+129) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = (b + t_0) / (a * -2.0);
} else {
tmp_3 = (c * 2.0) / (t_0 - b);
}
tmp_1 = tmp_3;
} else if (b >= 0.0) {
tmp_1 = (c / b) - (b / a);
} else {
tmp_1 = (c * 2.0) / (-b - b);
}
return tmp_1;
}
function code(a, b, c) t_0 = sqrt(fma(-4.0, Float64(a * c), Float64(b * b))) tmp_1 = 0.0 if (b <= -1.15e+154) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(Float64(-b) / a); else tmp_2 = Float64(c / Float64(-b)); end tmp_1 = tmp_2; elseif (b <= 3e+129) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(Float64(b + t_0) / Float64(a * -2.0)); else tmp_3 = Float64(Float64(c * 2.0) / Float64(t_0 - b)); end tmp_1 = tmp_3; elseif (b >= 0.0) tmp_1 = Float64(Float64(c / b) - Float64(b / a)); else tmp_1 = Float64(Float64(c * 2.0) / Float64(Float64(-b) - b)); end return tmp_1 end
code[a_, b_, c_] := Block[{t$95$0 = N[Sqrt[N[(-4.0 * N[(a * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[b, -1.15e+154], If[GreaterEqual[b, 0.0], N[((-b) / a), $MachinePrecision], N[(c / (-b)), $MachinePrecision]], If[LessEqual[b, 3e+129], If[GreaterEqual[b, 0.0], N[(N[(b + t$95$0), $MachinePrecision] / N[(a * -2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c * 2.0), $MachinePrecision] / N[(t$95$0 - b), $MachinePrecision]), $MachinePrecision]], If[GreaterEqual[b, 0.0], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], N[(N[(c * 2.0), $MachinePrecision] / N[((-b) - b), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\mathsf{fma}\left(-4, a \cdot c, b \cdot b\right)}\\
\mathbf{if}\;b \leq -1.15 \cdot 10^{+154}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{-b}\\
\end{array}\\
\mathbf{elif}\;b \leq 3 \cdot 10^{+129}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{b + t\_0}{a \cdot -2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot 2}{t\_0 - b}\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot 2}{\left(-b\right) - b}\\
\end{array}
\end{array}
if b < -1.15e154Initial program 42.6%
Taylor expanded in b around inf
*-commutativeN/A
lower-*.f6442.6
Applied rewrites42.6%
Taylor expanded in c around 0
mul-1-negN/A
distribute-neg-frac2N/A
neg-mul-1N/A
lower-/.f64N/A
neg-mul-1N/A
lower-neg.f642.3
Applied rewrites2.3%
Taylor expanded in b around inf
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f642.3
Applied rewrites2.3%
Taylor expanded in b around -inf
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6497.6
Applied rewrites97.6%
if -1.15e154 < b < 3.0000000000000003e129Initial program 87.8%
Applied rewrites87.7%
Applied rewrites87.8%
if 3.0000000000000003e129 < b Initial program 46.2%
Taylor expanded in c around 0
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f6497.2
Applied rewrites97.2%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f6497.2
Applied rewrites97.2%
Final simplification91.3%
herbie shell --seed 2024219
(FPCore (a b c)
:name "jeff quadratic root 1"
:precision binary64
(if (>= b 0.0) (/ (- (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)) (/ (* 2.0 c) (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))))))