
(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 3 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 (* -2.0 (* 0.5 (/ c b))))
(t_1 (sqrt (- (* b b) (* c (* a 4.0))))))
(if (<= b -6e+151)
(if (>= b 0.0) t_0 (/ (- b) a))
(if (<= b 1.45e+102)
(if (>= b 0.0) (/ (* c 2.0) (- (- b) t_1)) (/ (- t_1 b) (* a 2.0)))
(if (>= b 0.0) t_0 (- (/ c b) (/ b a)))))))
double code(double a, double b, double c) {
double t_0 = -2.0 * (0.5 * (c / b));
double t_1 = sqrt(((b * b) - (c * (a * 4.0))));
double tmp_1;
if (b <= -6e+151) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = t_0;
} else {
tmp_2 = -b / a;
}
tmp_1 = tmp_2;
} else if (b <= 1.45e+102) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = (c * 2.0) / (-b - t_1);
} else {
tmp_3 = (t_1 - b) / (a * 2.0);
}
tmp_1 = tmp_3;
} else if (b >= 0.0) {
tmp_1 = t_0;
} else {
tmp_1 = (c / b) - (b / a);
}
return tmp_1;
}
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) :: t_1
real(8) :: tmp
real(8) :: tmp_1
real(8) :: tmp_2
real(8) :: tmp_3
t_0 = (-2.0d0) * (0.5d0 * (c / b))
t_1 = sqrt(((b * b) - (c * (a * 4.0d0))))
if (b <= (-6d+151)) then
if (b >= 0.0d0) then
tmp_2 = t_0
else
tmp_2 = -b / a
end if
tmp_1 = tmp_2
else if (b <= 1.45d+102) then
if (b >= 0.0d0) then
tmp_3 = (c * 2.0d0) / (-b - t_1)
else
tmp_3 = (t_1 - b) / (a * 2.0d0)
end if
tmp_1 = tmp_3
else if (b >= 0.0d0) then
tmp_1 = t_0
else
tmp_1 = (c / b) - (b / a)
end if
code = tmp_1
end function
public static double code(double a, double b, double c) {
double t_0 = -2.0 * (0.5 * (c / b));
double t_1 = Math.sqrt(((b * b) - (c * (a * 4.0))));
double tmp_1;
if (b <= -6e+151) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = t_0;
} else {
tmp_2 = -b / a;
}
tmp_1 = tmp_2;
} else if (b <= 1.45e+102) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = (c * 2.0) / (-b - t_1);
} else {
tmp_3 = (t_1 - b) / (a * 2.0);
}
tmp_1 = tmp_3;
} else if (b >= 0.0) {
tmp_1 = t_0;
} else {
tmp_1 = (c / b) - (b / a);
}
return tmp_1;
}
def code(a, b, c): t_0 = -2.0 * (0.5 * (c / b)) t_1 = math.sqrt(((b * b) - (c * (a * 4.0)))) tmp_1 = 0 if b <= -6e+151: tmp_2 = 0 if b >= 0.0: tmp_2 = t_0 else: tmp_2 = -b / a tmp_1 = tmp_2 elif b <= 1.45e+102: tmp_3 = 0 if b >= 0.0: tmp_3 = (c * 2.0) / (-b - t_1) else: tmp_3 = (t_1 - b) / (a * 2.0) tmp_1 = tmp_3 elif b >= 0.0: tmp_1 = t_0 else: tmp_1 = (c / b) - (b / a) return tmp_1
function code(a, b, c) t_0 = Float64(-2.0 * Float64(0.5 * Float64(c / b))) t_1 = sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) tmp_1 = 0.0 if (b <= -6e+151) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = t_0; else tmp_2 = Float64(Float64(-b) / a); end tmp_1 = tmp_2; elseif (b <= 1.45e+102) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(Float64(c * 2.0) / Float64(Float64(-b) - t_1)); else tmp_3 = Float64(Float64(t_1 - b) / Float64(a * 2.0)); end tmp_1 = tmp_3; elseif (b >= 0.0) tmp_1 = t_0; else tmp_1 = Float64(Float64(c / b) - Float64(b / a)); end return tmp_1 end
function tmp_5 = code(a, b, c) t_0 = -2.0 * (0.5 * (c / b)); t_1 = sqrt(((b * b) - (c * (a * 4.0)))); tmp_2 = 0.0; if (b <= -6e+151) tmp_3 = 0.0; if (b >= 0.0) tmp_3 = t_0; else tmp_3 = -b / a; end tmp_2 = tmp_3; elseif (b <= 1.45e+102) tmp_4 = 0.0; if (b >= 0.0) tmp_4 = (c * 2.0) / (-b - t_1); else tmp_4 = (t_1 - b) / (a * 2.0); end tmp_2 = tmp_4; elseif (b >= 0.0) tmp_2 = t_0; else tmp_2 = (c / b) - (b / a); end tmp_5 = tmp_2; end
code[a_, b_, c_] := Block[{t$95$0 = N[(-2.0 * N[(0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[b, -6e+151], If[GreaterEqual[b, 0.0], t$95$0, N[((-b) / a), $MachinePrecision]], If[LessEqual[b, 1.45e+102], If[GreaterEqual[b, 0.0], N[(N[(c * 2.0), $MachinePrecision] / N[((-b) - t$95$1), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$1 - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]], If[GreaterEqual[b, 0.0], t$95$0, N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := -2 \cdot \left(0.5 \cdot \frac{c}{b}\right)\\
t_1 := \sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)}\\
\mathbf{if}\;b \leq -6 \cdot 10^{+151}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;t_0\\
\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\
\end{array}\\
\mathbf{elif}\;b \leq 1.45 \cdot 10^{+102}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;\frac{c \cdot 2}{\left(-b\right) - t_1}\\
\mathbf{else}:\\
\;\;\;\;\frac{t_1 - b}{a \cdot 2}\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;t_0\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}
\end{array}
if b < -5.9999999999999998e151Initial program 30.6%
Simplified30.6%
Taylor expanded in b around inf 30.6%
Taylor expanded in b around -inf 97.9%
mul-1-neg97.9%
unsub-neg97.9%
Simplified97.9%
Taylor expanded in c around 0 97.9%
Taylor expanded in c around 0 97.9%
neg-mul-197.9%
distribute-neg-frac97.9%
Simplified97.9%
if -5.9999999999999998e151 < b < 1.4500000000000001e102Initial program 91.3%
if 1.4500000000000001e102 < b Initial program 55.6%
Simplified55.6%
Taylor expanded in b around inf 96.3%
Taylor expanded in b around -inf 96.3%
mul-1-neg96.3%
unsub-neg96.3%
Simplified96.3%
Taylor expanded in c around 0 98.1%
Final simplification93.7%
(FPCore (a b c)
:precision binary64
(if (<= b -4.4e+150)
(if (>= b 0.0) (* -2.0 (* 0.5 (/ c b))) (/ (- b) a))
(if (>= b 0.0)
(/ 2.0 (/ (fma 2.0 (* (/ c b) a) (* b -2.0)) c))
(/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0)))))
double code(double a, double b, double c) {
double tmp_1;
if (b <= -4.4e+150) {
double tmp_2;
if (b >= 0.0) {
tmp_2 = -2.0 * (0.5 * (c / b));
} else {
tmp_2 = -b / a;
}
tmp_1 = tmp_2;
} else if (b >= 0.0) {
tmp_1 = 2.0 / (fma(2.0, ((c / b) * a), (b * -2.0)) / c);
} else {
tmp_1 = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
}
return tmp_1;
}
function code(a, b, c) tmp_1 = 0.0 if (b <= -4.4e+150) tmp_2 = 0.0 if (b >= 0.0) tmp_2 = Float64(-2.0 * Float64(0.5 * Float64(c / b))); else tmp_2 = Float64(Float64(-b) / a); end tmp_1 = tmp_2; elseif (b >= 0.0) tmp_1 = Float64(2.0 / Float64(fma(2.0, Float64(Float64(c / b) * a), Float64(b * -2.0)) / c)); else tmp_1 = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); end return tmp_1 end
code[a_, b_, c_] := If[LessEqual[b, -4.4e+150], If[GreaterEqual[b, 0.0], N[(-2.0 * N[(0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[((-b) / a), $MachinePrecision]], If[GreaterEqual[b, 0.0], N[(2.0 / N[(N[(2.0 * N[(N[(c / b), $MachinePrecision] * a), $MachinePrecision] + N[(b * -2.0), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -4.4 \cdot 10^{+150}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;-2 \cdot \left(0.5 \cdot \frac{c}{b}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{2}{\frac{\mathsf{fma}\left(2, \frac{c}{b} \cdot a, b \cdot -2\right)}{c}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\end{array}
\end{array}
if b < -4.39999999999999999e150Initial program 30.6%
Simplified30.6%
Taylor expanded in b around inf 30.6%
Taylor expanded in b around -inf 97.9%
mul-1-neg97.9%
unsub-neg97.9%
Simplified97.9%
Taylor expanded in c around 0 97.9%
Taylor expanded in c around 0 97.9%
neg-mul-197.9%
distribute-neg-frac97.9%
Simplified97.9%
if -4.39999999999999999e150 < b Initial program 82.9%
add-sqr-sqrt82.8%
pow282.8%
*-commutative82.8%
*-commutative82.8%
Applied egg-rr82.8%
Taylor expanded in b around inf 75.8%
fma-def75.8%
associate-/l*77.6%
associate-*r*77.6%
metadata-eval77.6%
*-commutative77.6%
Simplified77.6%
*-un-lft-identity77.6%
associate-/l*76.9%
associate-/r/76.8%
Applied egg-rr76.8%
Final simplification80.4%
(FPCore (a b c) :precision binary64 (if (>= b 0.0) (* -2.0 (* 0.5 (/ c b))) (- (/ c b) (/ b a))))
double code(double a, double b, double c) {
double tmp;
if (b >= 0.0) {
tmp = -2.0 * (0.5 * (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 >= 0.0d0) then
tmp = (-2.0d0) * (0.5d0 * (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 >= 0.0) {
tmp = -2.0 * (0.5 * (c / b));
} else {
tmp = (c / b) - (b / a);
}
return tmp;
}
def code(a, b, c): tmp = 0 if b >= 0.0: tmp = -2.0 * (0.5 * (c / b)) else: tmp = (c / b) - (b / a) return tmp
function code(a, b, c) tmp = 0.0 if (b >= 0.0) tmp = Float64(-2.0 * Float64(0.5 * 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 >= 0.0) tmp = -2.0 * (0.5 * (c / b)); else tmp = (c / b) - (b / a); end tmp_2 = tmp; end
code[a_, b_, c_] := If[GreaterEqual[b, 0.0], N[(-2.0 * N[(0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;-2 \cdot \left(0.5 \cdot \frac{c}{b}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}
\end{array}
Initial program 74.1%
Simplified74.1%
Taylor expanded in b around inf 69.5%
Taylor expanded in b around -inf 66.8%
mul-1-neg66.8%
unsub-neg66.8%
Simplified66.8%
Taylor expanded in c around 0 67.2%
Final simplification67.2%
herbie shell --seed 2023238
(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))))