
(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 (sqrt (- (* b b) (* c (* a 4.0))))))
(if (or (<= b -4e+84) (not (<= b 4.7e+58)))
(if (>= b 0.0) (/ (* 2.0 c) (* b -2.0)) (- (/ c b) (/ b a)))
(if (>= b 0.0) (/ (* 2.0 c) (- (- b) t_0)) (/ (- t_0 b) (* 2.0 a))))))
double code(double a, double b, double c) {
double t_0 = sqrt(((b * b) - (c * (a * 4.0))));
double tmp_1;
if ((b <= -4e+84) || !(b <= 4.7e+58)) {
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 >= 0.0) {
tmp_1 = (2.0 * c) / (-b - t_0);
} else {
tmp_1 = (t_0 - b) / (2.0 * 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) :: tmp
real(8) :: tmp_1
real(8) :: tmp_2
t_0 = sqrt(((b * b) - (c * (a * 4.0d0))))
if ((b <= (-4d+84)) .or. (.not. (b <= 4.7d+58))) then
if (b >= 0.0d0) then
tmp_2 = (2.0d0 * c) / (b * (-2.0d0))
else
tmp_2 = (c / b) - (b / a)
end if
tmp_1 = tmp_2
else if (b >= 0.0d0) then
tmp_1 = (2.0d0 * c) / (-b - t_0)
else
tmp_1 = (t_0 - b) / (2.0d0 * a)
end if
code = tmp_1
end function
public static double code(double a, double b, double c) {
double t_0 = Math.sqrt(((b * b) - (c * (a * 4.0))));
double tmp_1;
if ((b <= -4e+84) || !(b <= 4.7e+58)) {
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 >= 0.0) {
tmp_1 = (2.0 * c) / (-b - t_0);
} else {
tmp_1 = (t_0 - b) / (2.0 * a);
}
return tmp_1;
}
def code(a, b, c): t_0 = math.sqrt(((b * b) - (c * (a * 4.0)))) tmp_1 = 0 if (b <= -4e+84) or not (b <= 4.7e+58): tmp_2 = 0 if b >= 0.0: tmp_2 = (2.0 * c) / (b * -2.0) else: tmp_2 = (c / b) - (b / a) tmp_1 = tmp_2 elif b >= 0.0: tmp_1 = (2.0 * c) / (-b - t_0) else: tmp_1 = (t_0 - b) / (2.0 * a) return tmp_1
function code(a, b, c) t_0 = sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) tmp_1 = 0.0 if ((b <= -4e+84) || !(b <= 4.7e+58)) 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 >= 0.0) tmp_1 = Float64(Float64(2.0 * c) / Float64(Float64(-b) - t_0)); else tmp_1 = Float64(Float64(t_0 - b) / Float64(2.0 * a)); end return tmp_1 end
function tmp_4 = code(a, b, c) t_0 = sqrt(((b * b) - (c * (a * 4.0)))); tmp_2 = 0.0; if ((b <= -4e+84) || ~((b <= 4.7e+58))) tmp_3 = 0.0; if (b >= 0.0) tmp_3 = (2.0 * c) / (b * -2.0); else tmp_3 = (c / b) - (b / a); end tmp_2 = tmp_3; elseif (b >= 0.0) tmp_2 = (2.0 * c) / (-b - t_0); else tmp_2 = (t_0 - b) / (2.0 * a); end tmp_4 = tmp_2; 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]}, If[Or[LessEqual[b, -4e+84], N[Not[LessEqual[b, 4.7e+58]], $MachinePrecision]], 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[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[((-b) - t$95$0), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$0 - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)}\\
\mathbf{if}\;b \leq -4 \cdot 10^{+84} \lor \neg \left(b \leq 4.7 \cdot 10^{+58}\right):\\
\;\;\;\;\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 \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\left(-b\right) - t_0}\\
\mathbf{else}:\\
\;\;\;\;\frac{t_0 - b}{2 \cdot a}\\
\end{array}
\end{array}
if b < -4.00000000000000023e84 or 4.69999999999999972e58 < b Initial program 66.1%
add-sqr-sqrt66.1%
pow266.1%
pow1/266.1%
sqrt-pow166.1%
*-commutative66.1%
*-commutative66.1%
metadata-eval66.1%
Applied egg-rr66.1%
Taylor expanded in b around inf 83.1%
associate-*r*83.1%
metadata-eval83.1%
*-commutative83.1%
Simplified83.1%
Taylor expanded in b around -inf 98.4%
mul-1-neg98.4%
unsub-neg98.4%
Simplified98.4%
if -4.00000000000000023e84 < b < 4.69999999999999972e58Initial program 84.6%
Final simplification91.0%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (sqrt (- (* b b) (* c (* a 4.0))))))
(if (<= b -5.4e+84)
(if (>= b 0.0) (/ (* 2.0 c) (* b -2.0)) (- (/ c b) (/ b a)))
(if (<= b 1.15e-89)
(if (>= b 0.0) (* c (/ 2.0 (- b t_0))) (/ (- t_0 b) (* 2.0 a)))
(if (>= b 0.0)
(/ (* 2.0 c) (fma 2.0 (/ c (/ b a)) (* b -2.0)))
(pow (/ (* 2.0 a) (* b -2.0)) -1.0))))))
double code(double a, double b, double c) {
double t_0 = sqrt(((b * b) - (c * (a * 4.0))));
double tmp_1;
if (b <= -5.4e+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 <= 1.15e-89) {
double tmp_3;
if (b >= 0.0) {
tmp_3 = c * (2.0 / (b - t_0));
} else {
tmp_3 = (t_0 - b) / (2.0 * a);
}
tmp_1 = tmp_3;
} else if (b >= 0.0) {
tmp_1 = (2.0 * c) / fma(2.0, (c / (b / a)), (b * -2.0));
} else {
tmp_1 = pow(((2.0 * a) / (b * -2.0)), -1.0);
}
return tmp_1;
}
function code(a, b, c) t_0 = sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) tmp_1 = 0.0 if (b <= -5.4e+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 <= 1.15e-89) tmp_3 = 0.0 if (b >= 0.0) tmp_3 = Float64(c * Float64(2.0 / Float64(b - t_0))); else tmp_3 = Float64(Float64(t_0 - b) / Float64(2.0 * a)); end tmp_1 = tmp_3; elseif (b >= 0.0) tmp_1 = Float64(Float64(2.0 * c) / fma(2.0, Float64(c / Float64(b / a)), Float64(b * -2.0))); else tmp_1 = Float64(Float64(2.0 * a) / Float64(b * -2.0)) ^ -1.0; 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]}, If[LessEqual[b, -5.4e+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, 1.15e-89], If[GreaterEqual[b, 0.0], N[(c * N[(2.0 / N[(b - t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$0 - b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]], If[GreaterEqual[b, 0.0], N[(N[(2.0 * c), $MachinePrecision] / N[(2.0 * N[(c / N[(b / a), $MachinePrecision]), $MachinePrecision] + N[(b * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(2.0 * a), $MachinePrecision] / N[(b * -2.0), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)}\\
\mathbf{if}\;b \leq -5.4 \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 1.15 \cdot 10^{-89}:\\
\;\;\;\;\begin{array}{l}
\mathbf{if}\;b \geq 0:\\
\;\;\;\;c \cdot \frac{2}{b - t_0}\\
\mathbf{else}:\\
\;\;\;\;\frac{t_0 - b}{2 \cdot a}\\
\end{array}\\
\mathbf{elif}\;b \geq 0:\\
\;\;\;\;\frac{2 \cdot c}{\mathsf{fma}\left(2, \frac{c}{\frac{b}{a}}, b \cdot -2\right)}\\
\mathbf{else}:\\
\;\;\;\;{\left(\frac{2 \cdot a}{b \cdot -2}\right)}^{-1}\\
\end{array}
\end{array}
if b < -5.4e84Initial program 67.4%
add-sqr-sqrt67.4%
pow267.4%
pow1/267.4%
sqrt-pow167.4%
*-commutative67.4%
*-commutative67.4%
metadata-eval67.4%
Applied egg-rr67.4%
Taylor expanded in b around inf 67.4%
associate-*r*67.4%
metadata-eval67.4%
*-commutative67.4%
Simplified67.4%
Taylor expanded in b around -inf 96.9%
mul-1-neg96.9%
unsub-neg96.9%
Simplified96.9%
if -5.4e84 < b < 1.15e-89Initial program 81.3%
expm1-log1p-u76.3%
expm1-udef67.4%
*-commutative67.4%
add-sqr-sqrt64.1%
sqrt-unprod67.2%
sqr-neg67.2%
sqrt-prod67.2%
add-sqr-sqrt67.2%
*-commutative67.2%
*-commutative67.2%
Applied egg-rr67.2%
expm1-def76.0%
expm1-log1p80.9%
associate-*r/80.9%
Simplified80.9%
if 1.15e-89 < b Initial program 75.7%
add-sqr-sqrt75.6%
pow275.6%
pow1/275.6%
sqrt-pow175.6%
*-commutative75.6%
*-commutative75.6%
metadata-eval75.6%
Applied egg-rr75.6%
Taylor expanded in b around inf 89.2%
fma-def89.2%
associate-/l*91.5%
associate-*r*91.5%
metadata-eval91.5%
*-commutative91.5%
Simplified91.5%
clear-num91.5%
inv-pow91.5%
*-commutative91.5%
neg-mul-191.5%
fma-def91.5%
cancel-sign-sub-inv91.5%
fma-def91.5%
*-commutative91.5%
Applied egg-rr91.5%
Taylor expanded in b around -inf 91.5%
*-commutative91.5%
Simplified91.5%
Final simplification88.3%
(FPCore (a b c) :precision binary64 (if (>= b 0.0) (/ (* 2.0 c) (* b -2.0)) (- (/ c b) (/ b a))))
double code(double a, double b, double c) {
double tmp;
if (b >= 0.0) {
tmp = (2.0 * c) / (b * -2.0);
} 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 * c) / (b * (-2.0d0))
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 * c) / (b * -2.0);
} else {
tmp = (c / b) - (b / a);
}
return tmp;
}
def code(a, b, c): tmp = 0 if b >= 0.0: tmp = (2.0 * c) / (b * -2.0) else: tmp = (c / b) - (b / a) return tmp
function code(a, b, c) tmp = 0.0 if (b >= 0.0) tmp = Float64(Float64(2.0 * c) / Float64(b * -2.0)); 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 * c) / (b * -2.0); else tmp = (c / b) - (b / a); end tmp_2 = tmp; end
code[a_, b_, c_] := 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]]
\begin{array}{l}
\\
\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}
\end{array}
Initial program 76.1%
add-sqr-sqrt76.0%
pow276.0%
pow1/276.0%
sqrt-pow176.0%
*-commutative76.0%
*-commutative76.0%
metadata-eval76.0%
Applied egg-rr76.0%
Taylor expanded in b around inf 75.2%
associate-*r*75.2%
metadata-eval75.2%
*-commutative75.2%
Simplified75.2%
Taylor expanded in b around -inf 69.4%
mul-1-neg69.4%
unsub-neg69.4%
Simplified69.4%
Final simplification69.4%
herbie shell --seed 2023258
(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))))