
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (-b + sqrt(((b * b) - (4.0d0 * (a * c))))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(a * c))))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (-b + sqrt(((b * b) - (4.0d0 * (a * c))))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(a * c))))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - (4.0 * (a * c))))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -7.2e+109)
(/ (- b) a)
(if (<= b 2.15e-83)
(/ (- (sqrt (- (* b b) (* 4.0 (* a c)))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -7.2e+109) {
tmp = -b / a;
} else if (b <= 2.15e-83) {
tmp = (sqrt(((b * b) - (4.0 * (a * c)))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
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 <= (-7.2d+109)) then
tmp = -b / a
else if (b <= 2.15d-83) then
tmp = (sqrt(((b * b) - (4.0d0 * (a * c)))) - b) / (a * 2.0d0)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -7.2e+109) {
tmp = -b / a;
} else if (b <= 2.15e-83) {
tmp = (Math.sqrt(((b * b) - (4.0 * (a * c)))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -7.2e+109: tmp = -b / a elif b <= 2.15e-83: tmp = (math.sqrt(((b * b) - (4.0 * (a * c)))) - b) / (a * 2.0) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -7.2e+109) tmp = Float64(Float64(-b) / a); elseif (b <= 2.15e-83) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(a * c)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -7.2e+109) tmp = -b / a; elseif (b <= 2.15e-83) tmp = (sqrt(((b * b) - (4.0 * (a * c)))) - b) / (a * 2.0); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -7.2e+109], N[((-b) / a), $MachinePrecision], If[LessEqual[b, 2.15e-83], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -7.2 \cdot 10^{+109}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{elif}\;b \leq 2.15 \cdot 10^{-83}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -7.2e109Initial program 58.3%
*-commutative58.3%
Simplified58.3%
Taylor expanded in b around -inf 96.6%
associate-*r/96.6%
mul-1-neg96.6%
Simplified96.6%
if -7.2e109 < b < 2.15000000000000017e-83Initial program 84.7%
if 2.15000000000000017e-83 < b Initial program 15.0%
*-commutative15.0%
Simplified15.0%
Taylor expanded in b around inf 85.1%
associate-*r/85.1%
neg-mul-185.1%
Simplified85.1%
Final simplification87.4%
(FPCore (a b c)
:precision binary64
(if (<= b -1.85e-63)
(- (/ c b) (/ b a))
(if (<= b 6.7e-84)
(/ (- (sqrt (* a (* c -4.0))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -1.85e-63) {
tmp = (c / b) - (b / a);
} else if (b <= 6.7e-84) {
tmp = (sqrt((a * (c * -4.0))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
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 <= (-1.85d-63)) then
tmp = (c / b) - (b / a)
else if (b <= 6.7d-84) then
tmp = (sqrt((a * (c * (-4.0d0)))) - b) / (a * 2.0d0)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -1.85e-63) {
tmp = (c / b) - (b / a);
} else if (b <= 6.7e-84) {
tmp = (Math.sqrt((a * (c * -4.0))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -1.85e-63: tmp = (c / b) - (b / a) elif b <= 6.7e-84: tmp = (math.sqrt((a * (c * -4.0))) - b) / (a * 2.0) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -1.85e-63) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 6.7e-84) tmp = Float64(Float64(sqrt(Float64(a * Float64(c * -4.0))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -1.85e-63) tmp = (c / b) - (b / a); elseif (b <= 6.7e-84) tmp = (sqrt((a * (c * -4.0))) - b) / (a * 2.0); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -1.85e-63], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 6.7e-84], N[(N[(N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.85 \cdot 10^{-63}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 6.7 \cdot 10^{-84}:\\
\;\;\;\;\frac{\sqrt{a \cdot \left(c \cdot -4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -1.85000000000000006e-63Initial program 74.8%
*-commutative74.8%
Simplified74.8%
Taylor expanded in b around -inf 88.8%
+-commutative88.8%
mul-1-neg88.8%
unsub-neg88.8%
Simplified88.8%
if -1.85000000000000006e-63 < b < 6.7e-84Initial program 78.4%
*-commutative78.4%
Simplified78.4%
add-sqr-sqrt78.1%
pow278.1%
pow1/278.1%
sqrt-pow178.2%
fma-neg78.2%
distribute-lft-neg-in78.2%
*-commutative78.2%
associate-*r*78.2%
metadata-eval78.2%
metadata-eval78.2%
Applied egg-rr78.2%
Taylor expanded in c around inf 30.4%
Simplified74.3%
if 6.7e-84 < b Initial program 15.0%
*-commutative15.0%
Simplified15.0%
Taylor expanded in b around inf 85.1%
associate-*r/85.1%
neg-mul-185.1%
Simplified85.1%
Final simplification83.3%
(FPCore (a b c) :precision binary64 (if (<= b 1.95e+28) (/ (- b) a) (/ c b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 1.95e+28) {
tmp = -b / a;
} else {
tmp = c / b;
}
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 <= 1.95d+28) then
tmp = -b / a
else
tmp = c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 1.95e+28) {
tmp = -b / a;
} else {
tmp = c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 1.95e+28: tmp = -b / a else: tmp = c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= 1.95e+28) tmp = Float64(Float64(-b) / a); else tmp = Float64(c / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 1.95e+28) tmp = -b / a; else tmp = c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 1.95e+28], N[((-b) / a), $MachinePrecision], N[(c / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 1.95 \cdot 10^{+28}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b}\\
\end{array}
\end{array}
if b < 1.9499999999999999e28Initial program 71.2%
*-commutative71.2%
Simplified71.2%
Taylor expanded in b around -inf 48.5%
associate-*r/48.5%
mul-1-neg48.5%
Simplified48.5%
if 1.9499999999999999e28 < b Initial program 9.4%
*-commutative9.4%
Simplified9.4%
Taylor expanded in b around -inf 2.1%
+-commutative2.1%
mul-1-neg2.1%
unsub-neg2.1%
associate-/l*2.4%
associate-*r/2.4%
*-commutative2.4%
Simplified2.4%
Taylor expanded in b around 0 30.9%
Final simplification44.4%
(FPCore (a b c) :precision binary64 (if (<= b 1.1e-266) (/ (- b) a) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 1.1e-266) {
tmp = -b / a;
} else {
tmp = -c / b;
}
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 <= 1.1d-266) then
tmp = -b / a
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 1.1e-266) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 1.1e-266: tmp = -b / a else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= 1.1e-266) tmp = Float64(Float64(-b) / a); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 1.1e-266) tmp = -b / a; else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 1.1e-266], N[((-b) / a), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 1.1 \cdot 10^{-266}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < 1.1e-266Initial program 77.0%
*-commutative77.0%
Simplified77.0%
Taylor expanded in b around -inf 62.7%
associate-*r/62.7%
mul-1-neg62.7%
Simplified62.7%
if 1.1e-266 < b Initial program 28.6%
*-commutative28.6%
Simplified28.6%
Taylor expanded in b around inf 69.9%
associate-*r/69.9%
neg-mul-169.9%
Simplified69.9%
Final simplification65.7%
(FPCore (a b c) :precision binary64 (/ c b))
double code(double a, double b, double c) {
return c / b;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = c / b
end function
public static double code(double a, double b, double c) {
return c / b;
}
def code(a, b, c): return c / b
function code(a, b, c) return Float64(c / b) end
function tmp = code(a, b, c) tmp = c / b; end
code[a_, b_, c_] := N[(c / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{b}
\end{array}
Initial program 56.9%
*-commutative56.9%
Simplified56.9%
Taylor expanded in b around -inf 36.8%
+-commutative36.8%
mul-1-neg36.8%
unsub-neg36.8%
associate-/l*37.6%
associate-*r/37.6%
*-commutative37.6%
Simplified37.6%
Taylor expanded in b around 0 9.7%
Final simplification9.7%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (fabs (/ b 2.0)))
(t_1 (* (sqrt (fabs a)) (sqrt (fabs c))))
(t_2
(if (== (copysign a c) a)
(* (sqrt (- t_0 t_1)) (sqrt (+ t_0 t_1)))
(hypot (/ b 2.0) t_1))))
(if (< b 0.0) (/ (- t_2 (/ b 2.0)) a) (/ (- c) (+ (/ b 2.0) t_2)))))
double code(double a, double b, double c) {
double t_0 = fabs((b / 2.0));
double t_1 = sqrt(fabs(a)) * sqrt(fabs(c));
double tmp;
if (copysign(a, c) == a) {
tmp = sqrt((t_0 - t_1)) * sqrt((t_0 + t_1));
} else {
tmp = hypot((b / 2.0), t_1);
}
double t_2 = tmp;
double tmp_1;
if (b < 0.0) {
tmp_1 = (t_2 - (b / 2.0)) / a;
} else {
tmp_1 = -c / ((b / 2.0) + t_2);
}
return tmp_1;
}
public static double code(double a, double b, double c) {
double t_0 = Math.abs((b / 2.0));
double t_1 = Math.sqrt(Math.abs(a)) * Math.sqrt(Math.abs(c));
double tmp;
if (Math.copySign(a, c) == a) {
tmp = Math.sqrt((t_0 - t_1)) * Math.sqrt((t_0 + t_1));
} else {
tmp = Math.hypot((b / 2.0), t_1);
}
double t_2 = tmp;
double tmp_1;
if (b < 0.0) {
tmp_1 = (t_2 - (b / 2.0)) / a;
} else {
tmp_1 = -c / ((b / 2.0) + t_2);
}
return tmp_1;
}
def code(a, b, c): t_0 = math.fabs((b / 2.0)) t_1 = math.sqrt(math.fabs(a)) * math.sqrt(math.fabs(c)) tmp = 0 if math.copysign(a, c) == a: tmp = math.sqrt((t_0 - t_1)) * math.sqrt((t_0 + t_1)) else: tmp = math.hypot((b / 2.0), t_1) t_2 = tmp tmp_1 = 0 if b < 0.0: tmp_1 = (t_2 - (b / 2.0)) / a else: tmp_1 = -c / ((b / 2.0) + t_2) return tmp_1
function code(a, b, c) t_0 = abs(Float64(b / 2.0)) t_1 = Float64(sqrt(abs(a)) * sqrt(abs(c))) tmp = 0.0 if (copysign(a, c) == a) tmp = Float64(sqrt(Float64(t_0 - t_1)) * sqrt(Float64(t_0 + t_1))); else tmp = hypot(Float64(b / 2.0), t_1); end t_2 = tmp tmp_1 = 0.0 if (b < 0.0) tmp_1 = Float64(Float64(t_2 - Float64(b / 2.0)) / a); else tmp_1 = Float64(Float64(-c) / Float64(Float64(b / 2.0) + t_2)); end return tmp_1 end
function tmp_3 = code(a, b, c) t_0 = abs((b / 2.0)); t_1 = sqrt(abs(a)) * sqrt(abs(c)); tmp = 0.0; if ((sign(c) * abs(a)) == a) tmp = sqrt((t_0 - t_1)) * sqrt((t_0 + t_1)); else tmp = hypot((b / 2.0), t_1); end t_2 = tmp; tmp_2 = 0.0; if (b < 0.0) tmp_2 = (t_2 - (b / 2.0)) / a; else tmp_2 = -c / ((b / 2.0) + t_2); end tmp_3 = tmp_2; end
code[a_, b_, c_] := Block[{t$95$0 = N[Abs[N[(b / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[Sqrt[N[Abs[a], $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[Abs[c], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = If[Equal[N[With[{TMP1 = Abs[a], TMP2 = Sign[c]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], a], N[(N[Sqrt[N[(t$95$0 - t$95$1), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(t$95$0 + t$95$1), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Sqrt[N[(b / 2.0), $MachinePrecision] ^ 2 + t$95$1 ^ 2], $MachinePrecision]]}, If[Less[b, 0.0], N[(N[(t$95$2 - N[(b / 2.0), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision], N[((-c) / N[(N[(b / 2.0), $MachinePrecision] + t$95$2), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left|\frac{b}{2}\right|\\
t_1 := \sqrt{\left|a\right|} \cdot \sqrt{\left|c\right|}\\
t_2 := \begin{array}{l}
\mathbf{if}\;\mathsf{copysign}\left(a, c\right) = a:\\
\;\;\;\;\sqrt{t\_0 - t\_1} \cdot \sqrt{t\_0 + t\_1}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(\frac{b}{2}, t\_1\right)\\
\end{array}\\
\mathbf{if}\;b < 0:\\
\;\;\;\;\frac{t\_2 - \frac{b}{2}}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{\frac{b}{2} + t\_2}\\
\end{array}
\end{array}
herbie shell --seed 2024029
(FPCore (a b c)
:name "quadp (p42, positive)"
:precision binary64
:herbie-expected 10
:herbie-target
(if (< b 0.0) (/ (- (if (== (copysign a c) a) (* (sqrt (- (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c))))) (sqrt (+ (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (hypot (/ b 2.0) (* (sqrt (fabs a)) (sqrt (fabs c))))) (/ b 2.0)) a) (/ (- c) (+ (/ b 2.0) (if (== (copysign a c) a) (* (sqrt (- (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c))))) (sqrt (+ (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (hypot (/ b 2.0) (* (sqrt (fabs a)) (sqrt (fabs c))))))))
(/ (+ (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))