
(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
(let* ((t_0 (sqrt (fma (* a c) -4.0 (* b b)))) (t_1 (/ (- b) a)))
(if (<= b -1e+142)
(if (>= b 0.0)
(/ (- (- b) (sqrt (* b b))) (* a 2.0))
(/ (* c 2.0) (* 2.0 (fma a (/ c b) (- b)))))
(if (<= b 8.5e+122)
(if (>= b 0.0) (/ (* -0.5 (+ b t_0)) a) (/ (* c 2.0) (- t_0 b)))
(if (>= b 0.0) t_1 t_1)))))
double code(double a, double b, double c) {
double t_0 = sqrt(fma((a * c), -4.0, (b * b)));
double t_1 = -b / a;
double tmp_1;
if (b <= -1e+142) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = (-b - sqrt((b * b))) / (a * 2.0);
} else {
tmp_2 = (c * 2.0) / (2.0 * fma(a, (c / b), -b));
}
tmp_1 = tmp_2;
} else if (b <= 8.5e+122) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = (-0.5 * (b + t_0)) / a;
} else {
tmp_3 = (c * 2.0) / (t_0 - b);
}
tmp_1 = tmp_3;
} else if (b >= 0.0) {
tmp_1 = t_1;
} else {
tmp_1 = t_1;
}
return tmp_1;
}
function code(a, b, c) t_0 = sqrt(fma(Float64(a * c), -4.0, Float64(b * b))) t_1 = Float64(Float64(-b) / a) tmp_1 = 0.0 if (b <= -1e+142) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(Float64(Float64(-b) - sqrt(Float64(b * b))) / Float64(a * 2.0)); else tmp_2 = Float64(Float64(c * 2.0) / Float64(2.0 * fma(a, Float64(c / b), Float64(-b)))); end tmp_1 = tmp_2; elseif (b <= 8.5e+122) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(Float64(-0.5 * Float64(b + t_0)) / a); else tmp_3 = Float64(Float64(c * 2.0) / Float64(t_0 - b)); end tmp_1 = tmp_3; elseif (b >= 0.0) tmp_1 = t_1; else tmp_1 = t_1; end return tmp_1 end
code[a_, b_, c_] := Block[{t$95$0 = N[Sqrt[N[(N[(a * c), $MachinePrecision] * -4.0 + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[((-b) / a), $MachinePrecision]}, If[LessEqual[b, -1e+142], If[GreaterEqual[b, 0.0], N[(N[((-b) - N[Sqrt[N[(b * b), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c * 2.0), $MachinePrecision] / N[(2.0 * N[(a * N[(c / b), $MachinePrecision] + (-b)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], If[LessEqual[b, 8.5e+122], If[GreaterEqual[b, 0.0], N[(N[(-0.5 * N[(b + t$95$0), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision], N[(N[(c * 2.0), $MachinePrecision] / N[(t$95$0 - b), $MachinePrecision]), $MachinePrecision]], If[GreaterEqual[b, 0.0], t$95$1, t$95$1]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\mathsf{fma}\left(a \cdot c, -4, b \cdot b\right)}\\
t_1 := \frac{-b}{a}\\
\mathbf{if}\;b \leq -1 \cdot 10^{+142}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b}}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot 2}{2 \cdot \mathsf{fma}\left(a, \frac{c}{b}, -b\right)}\\
\end{array}\\
\mathbf{elif}\;b \leq 8.5 \cdot 10^{+122}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{-0.5 \cdot \left(b + t\_0\right)}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot 2}{t\_0 - b}\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;t\_1\\
\mathbf{else}:\\
\;\;\;\;t\_1\\
\end{array}
\end{array}
if b < -1.00000000000000005e142Initial program 34.1%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f64N/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6496.1
Applied rewrites96.1%
Taylor expanded in a around 0
Applied rewrites96.1%
Taylor expanded in b around inf
unpow2N/A
lower-*.f6496.1
Applied rewrites96.1%
if -1.00000000000000005e142 < b < 8.50000000000000003e122Initial program 86.1%
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.f6465.4
Applied rewrites65.4%
Taylor expanded in b around 0
Applied rewrites86.1%
if 8.50000000000000003e122 < b Initial program 51.8%
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.f6498.7
Applied rewrites98.7%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6498.7
Applied rewrites98.7%
Final simplification91.2%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (/ (* c 2.0) (* 2.0 (fma a (/ c b) (- b)))))
(t_1 (sqrt (* (* a c) -4.0))))
(if (<= b -1.82e-103)
(if (>= b 0.0) (/ (- (- b) (sqrt (* b b))) (* a 2.0)) t_0)
(if (<= b 1.8e-306)
(if (>= b 0.0)
(/ (- (- b) (fma a (/ (* c -2.0) b) b)) (* a 2.0))
(/ (* c 2.0) (- t_1 b)))
(if (<= b 6e-147)
(if (>= b 0.0) (/ (- (- b) t_1) (* a 2.0)) t_0)
(if (>= b 0.0) (- (/ c b) (/ b a)) (/ (- b) a)))))))
double code(double a, double b, double c) {
double t_0 = (c * 2.0) / (2.0 * fma(a, (c / b), -b));
double t_1 = sqrt(((a * c) * -4.0));
double tmp_1;
if (b <= -1.82e-103) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = (-b - sqrt((b * b))) / (a * 2.0);
} else {
tmp_2 = t_0;
}
tmp_1 = tmp_2;
} else if (b <= 1.8e-306) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = (-b - fma(a, ((c * -2.0) / b), b)) / (a * 2.0);
} else {
tmp_3 = (c * 2.0) / (t_1 - b);
}
tmp_1 = tmp_3;
} else if (b <= 6e-147) {
double tmp_4;
if (b >= 0.0) {
tmp_4 = (-b - t_1) / (a * 2.0);
} else {
tmp_4 = t_0;
}
tmp_1 = tmp_4;
} else if (b >= 0.0) {
tmp_1 = (c / b) - (b / a);
} else {
tmp_1 = -b / a;
}
return tmp_1;
}
function code(a, b, c) t_0 = Float64(Float64(c * 2.0) / Float64(2.0 * fma(a, Float64(c / b), Float64(-b)))) t_1 = sqrt(Float64(Float64(a * c) * -4.0)) tmp_1 = 0.0 if (b <= -1.82e-103) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(Float64(Float64(-b) - sqrt(Float64(b * b))) / Float64(a * 2.0)); else tmp_2 = t_0; end tmp_1 = tmp_2; elseif (b <= 1.8e-306) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(Float64(Float64(-b) - fma(a, Float64(Float64(c * -2.0) / b), b)) / Float64(a * 2.0)); else tmp_3 = Float64(Float64(c * 2.0) / Float64(t_1 - b)); end tmp_1 = tmp_3; elseif (b <= 6e-147) tmp_4 = 0.0 if (b >= 0.0) tmp_4 = Float64(Float64(Float64(-b) - t_1) / Float64(a * 2.0)); else tmp_4 = t_0; end tmp_1 = tmp_4; elseif (b >= 0.0) tmp_1 = Float64(Float64(c / b) - Float64(b / a)); else tmp_1 = Float64(Float64(-b) / a); end return tmp_1 end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(c * 2.0), $MachinePrecision] / N[(2.0 * N[(a * N[(c / b), $MachinePrecision] + (-b)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[Sqrt[N[(N[(a * c), $MachinePrecision] * -4.0), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[b, -1.82e-103], If[GreaterEqual[b, 0.0], N[(N[((-b) - N[Sqrt[N[(b * b), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], t$95$0], If[LessEqual[b, 1.8e-306], If[GreaterEqual[b, 0.0], N[(N[((-b) - N[(a * N[(N[(c * -2.0), $MachinePrecision] / b), $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c * 2.0), $MachinePrecision] / N[(t$95$1 - b), $MachinePrecision]), $MachinePrecision]], If[LessEqual[b, 6e-147], If[GreaterEqual[b, 0.0], N[(N[((-b) - t$95$1), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], t$95$0], If[GreaterEqual[b, 0.0], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], N[((-b) / a), $MachinePrecision]]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{c \cdot 2}{2 \cdot \mathsf{fma}\left(a, \frac{c}{b}, -b\right)}\\
t_1 := \sqrt{\left(a \cdot c\right) \cdot -4}\\
\mathbf{if}\;b \leq -1.82 \cdot 10^{-103}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b}}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}\\
\mathbf{elif}\;b \leq 1.8 \cdot 10^{-306}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{\left(-b\right) - \mathsf{fma}\left(a, \frac{c \cdot -2}{b}, b\right)}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c \cdot 2}{t\_1 - b}\\
\end{array}\\
\mathbf{elif}\;b \leq 6 \cdot 10^{-147}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{\left(-b\right) - t\_1}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\
\end{array}
\end{array}
if b < -1.8199999999999999e-103Initial program 69.0%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f64N/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6483.3
Applied rewrites83.3%
Taylor expanded in a around 0
Applied rewrites83.3%
Taylor expanded in b around inf
unpow2N/A
lower-*.f6483.3
Applied rewrites83.3%
if -1.8199999999999999e-103 < b < 1.79999999999999996e-306Initial program 78.3%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
associate-/l*N/A
associate-*r*N/A
*-commutativeN/A
lower-fma.f64N/A
associate-*r/N/A
lower-/.f64N/A
lower-*.f6477.7
Applied rewrites77.7%
Taylor expanded in b around 0
*-commutativeN/A
lower-*.f64N/A
lower-*.f6470.1
Applied rewrites70.1%
if 1.79999999999999996e-306 < b < 6.0000000000000004e-147Initial program 79.0%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f64N/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6479.0
Applied rewrites79.0%
Taylor expanded in a around 0
Applied rewrites79.0%
Taylor expanded in b around 0
lower-*.f64N/A
*-commutativeN/A
lower-*.f6477.8
Applied rewrites77.8%
if 6.0000000000000004e-147 < b Initial program 72.3%
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.f6480.0
Applied rewrites80.0%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6480.0
Applied rewrites80.0%
Taylor expanded in c around 0
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f6480.4
Applied rewrites80.4%
Final simplification80.0%
herbie shell --seed 2024229
(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)))))))