
(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 12 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
(let* ((t_0 (sqrt (- (* b b) (* c (* a 4.0))))) (t_1 (/ (- t_0 b) (* 2.0 a))))
(if (<= b -2e+147)
(if (>= b 0.0) (/ b a) (/ b (- a)))
(if (<= b 1.5e+84)
(if (>= b 0.0) (/ (* 2.0 c) (- (- b) t_0)) t_1)
(if (>= b 0.0)
(/ (* 2.0 c) (* b (fma 2.0 (* a (/ c (* b b))) -2.0)))
t_1)))))
double code(double a, double b, double c) {
double t_0 = sqrt(((b * b) - (c * (a * 4.0))));
double t_1 = (t_0 - b) / (2.0 * a);
double tmp_1;
if (b <= -2e+147) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = b / a;
} else {
tmp_2 = b / -a;
}
tmp_1 = tmp_2;
} else if (b <= 1.5e+84) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = (2.0 * c) / (-b - t_0);
} else {
tmp_3 = t_1;
}
tmp_1 = tmp_3;
} else if (b >= 0.0) {
tmp_1 = (2.0 * c) / (b * fma(2.0, (a * (c / (b * b))), -2.0));
} else {
tmp_1 = t_1;
}
return tmp_1;
}
function code(a, b, c) t_0 = sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) t_1 = Float64(Float64(t_0 - b) / Float64(2.0 * a)) tmp_1 = 0.0 if (b <= -2e+147) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(b / a); else tmp_2 = Float64(b / Float64(-a)); end tmp_1 = tmp_2; elseif (b <= 1.5e+84) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(Float64(2.0 * c) / Float64(Float64(-b) - t_0)); else tmp_3 = t_1; end tmp_1 = tmp_3; elseif (b >= 0.0) tmp_1 = Float64(Float64(2.0 * c) / Float64(b * fma(2.0, Float64(a * Float64(c / Float64(b * b))), -2.0))); else tmp_1 = t_1; end return tmp_1 end
code[a_, b_, c_] := Block[{t$95$0 = N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(t$95$0 - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[b, -2e+147], If[GreaterEqual[b, 0.0], N[(b / a), $MachinePrecision], N[(b / (-a)), $MachinePrecision]], If[LessEqual[b, 1.5e+84], If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - t$95$0), $MachinePrecision]), $MachinePrecision], t$95$1], If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[(b * N[(2.0 * N[(a * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$1]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)}\\
t_1 := \frac{t\_0 - b}{2 \cdot a}\\
\mathbf{if}\;b \leq -2 \cdot 10^{+147}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{b}{-a}\\
\end{array}\\
\mathbf{elif}\;b \leq 1.5 \cdot 10^{+84}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - t\_0}\\
\mathbf{else}:\\
\;\;\;\;t\_1\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{b \cdot \mathsf{fma}\left(2, a \cdot \frac{c}{b \cdot b}, -2\right)}\\
\mathbf{else}:\\
\;\;\;\;t\_1\\
\end{array}
\end{array}
if b < -2e147Initial program 37.1%
Applied rewrites37.1%
Taylor expanded in b around inf
lower-/.f6437.1
Applied rewrites37.1%
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.f6497.3
Applied rewrites97.3%
if -2e147 < b < 1.49999999999999998e84Initial program 92.0%
if 1.49999999999999998e84 < b Initial program 65.0%
Taylor expanded in b around inf
lower-*.f64N/A
sub-negN/A
metadata-evalN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6492.5
Applied rewrites92.5%
Final simplification92.9%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (/ c (* b b))))
(if (<= b -2e+147)
(if (>= b 0.0) (/ b a) (/ b (- a)))
(if (<= b -5e-310)
(if (>= b 0.0)
(* b (- (/ 1.0 a) t_0))
(/ (- (sqrt (fma c (* a -4.0) (* b b))) b) (* 2.0 a)))
(if (<= b 1.5e+84)
(if (>= b 0.0)
(* c (/ -2.0 (+ b (sqrt (fma b b (* a (* c -4.0)))))))
(* b (+ t_0 (/ -1.0 a))))
(if (>= b 0.0) (/ c (- b)) (/ (- (- b) b) (* 2.0 a))))))))
double code(double a, double b, double c) {
double t_0 = c / (b * b);
double tmp_1;
if (b <= -2e+147) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = b / a;
} else {
tmp_2 = b / -a;
}
tmp_1 = tmp_2;
} else if (b <= -5e-310) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = b * ((1.0 / a) - t_0);
} else {
tmp_3 = (sqrt(fma(c, (a * -4.0), (b * b))) - b) / (2.0 * a);
}
tmp_1 = tmp_3;
} else if (b <= 1.5e+84) {
double tmp_4;
if (b >= 0.0) {
tmp_4 = c * (-2.0 / (b + sqrt(fma(b, b, (a * (c * -4.0))))));
} else {
tmp_4 = b * (t_0 + (-1.0 / a));
}
tmp_1 = tmp_4;
} else if (b >= 0.0) {
tmp_1 = c / -b;
} else {
tmp_1 = (-b - b) / (2.0 * a);
}
return tmp_1;
}
function code(a, b, c) t_0 = Float64(c / Float64(b * b)) tmp_1 = 0.0 if (b <= -2e+147) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(b / a); else tmp_2 = Float64(b / Float64(-a)); end tmp_1 = tmp_2; elseif (b <= -5e-310) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(b * Float64(Float64(1.0 / a) - t_0)); else tmp_3 = Float64(Float64(sqrt(fma(c, Float64(a * -4.0), Float64(b * b))) - b) / Float64(2.0 * a)); end tmp_1 = tmp_3; elseif (b <= 1.5e+84) tmp_4 = 0.0 if (b >= 0.0) tmp_4 = Float64(c * Float64(-2.0 / Float64(b + sqrt(fma(b, b, Float64(a * Float64(c * -4.0))))))); else tmp_4 = Float64(b * Float64(t_0 + Float64(-1.0 / a))); end tmp_1 = tmp_4; elseif (b >= 0.0) tmp_1 = Float64(c / Float64(-b)); else tmp_1 = Float64(Float64(Float64(-b) - b) / Float64(2.0 * a)); end return tmp_1 end
code[a_, b_, c_] := Block[{t$95$0 = N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[b, -2e+147], If[GreaterEqual[b, 0.0], N[(b / a), $MachinePrecision], N[(b / (-a)), $MachinePrecision]], If[LessEqual[b, -5e-310], If[GreaterEqual[b, 0.0], N[(b * N[(N[(1.0 / a), $MachinePrecision] - t$95$0), $MachinePrecision]), $MachinePrecision], N[(N[(N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]], If[LessEqual[b, 1.5e+84], If[GreaterEqual[b, 0.0], N[(c * N[(-2.0 / N[(b + N[Sqrt[N[(b * b + N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(b * N[(t$95$0 + N[(-1.0 / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], If[GreaterEqual[b, 0.0], N[(c / (-b)), $MachinePrecision], N[(N[((-b) - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{c}{b \cdot b}\\
\mathbf{if}\;b \leq -2 \cdot 10^{+147}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{b}{-a}\\
\end{array}\\
\mathbf{elif}\;b \leq -5 \cdot 10^{-310}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;b \cdot \left(\frac{1}{a} - t\_0\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(c, a \cdot -4, b \cdot b\right)} - b}{2 \cdot a}\\
\end{array}\\
\mathbf{elif}\;b \leq 1.5 \cdot 10^{+84}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;c \cdot \frac{-2}{b + \sqrt{\mathsf{fma}\left(b, b, a \cdot \left(c \cdot -4\right)\right)}}\\
\mathbf{else}:\\
\;\;\;\;b \cdot \left(t\_0 + \frac{-1}{a}\right)\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{c}{-b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(-b\right) - b}{2 \cdot a}\\
\end{array}
\end{array}
if b < -2e147Initial program 43.7%
Applied rewrites43.7%
Taylor expanded in b around inf
lower-/.f6443.7
Applied rewrites43.7%
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.f6498.3
Applied rewrites98.3%
if -2e147 < b < -4.999999999999985e-310Initial program 88.4%
Applied rewrites88.4%
Taylor expanded in b around inf
lower-*.f64N/A
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6488.4
Applied rewrites88.4%
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6488.4
lift--.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
lift-*.f64N/A
cancel-sign-sub-invN/A
metadata-evalN/A
*-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f64N/A
+-commutativeN/A
lift-fma.f6488.4
Applied rewrites88.4%
if -4.999999999999985e-310 < b < 1.49999999999999998e84Initial program 86.4%
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-*.f6486.4
Applied rewrites86.4%
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/l*N/A
metadata-evalN/A
metadata-evalN/A
lift--.f64N/A
sub-negN/A
lift-neg.f64N/A
distribute-neg-outN/A
lift--.f64N/A
sub-negN/A
lift-*.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
lift-*.f64N/A
distribute-lft-neg-inN/A
metadata-evalN/A
*-commutativeN/A
lift-*.f64N/A
Applied rewrites86.2%
if 1.49999999999999998e84 < b Initial program 57.4%
Applied rewrites30.9%
Taylor expanded in b around inf
lower-*.f64N/A
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f642.8
Applied rewrites2.8%
Taylor expanded in b around -inf
mul-1-negN/A
lower-neg.f642.8
Applied rewrites2.8%
Taylor expanded in b around 0
Applied rewrites95.5%
Final simplification91.1%
herbie shell --seed 2024228
(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))))