
(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(Float64(4.0 * 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[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{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(Float64(4.0 * 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[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(let* ((t_0 (* c (* a 4.0))))
(/
(+ (- (pow (- b) 2.0) (* b b)) t_0)
(* (* 2.0 a) (- (- b) (sqrt (- (* b b) t_0)))))))
double code(double a, double b, double c) {
double t_0 = c * (a * 4.0);
return ((pow(-b, 2.0) - (b * b)) + t_0) / ((2.0 * a) * (-b - sqrt(((b * b) - t_0))));
}
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
t_0 = c * (a * 4.0d0)
code = (((-b ** 2.0d0) - (b * b)) + t_0) / ((2.0d0 * a) * (-b - sqrt(((b * b) - t_0))))
end function
public static double code(double a, double b, double c) {
double t_0 = c * (a * 4.0);
return ((Math.pow(-b, 2.0) - (b * b)) + t_0) / ((2.0 * a) * (-b - Math.sqrt(((b * b) - t_0))));
}
def code(a, b, c): t_0 = c * (a * 4.0) return ((math.pow(-b, 2.0) - (b * b)) + t_0) / ((2.0 * a) * (-b - math.sqrt(((b * b) - t_0))))
function code(a, b, c) t_0 = Float64(c * Float64(a * 4.0)) return Float64(Float64(Float64((Float64(-b) ^ 2.0) - Float64(b * b)) + t_0) / Float64(Float64(2.0 * a) * Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - t_0))))) end
function tmp = code(a, b, c) t_0 = c * (a * 4.0); tmp = (((-b ^ 2.0) - (b * b)) + t_0) / ((2.0 * a) * (-b - sqrt(((b * b) - t_0)))); end
code[a_, b_, c_] := Block[{t$95$0 = N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[Power[(-b), 2.0], $MachinePrecision] - N[(b * b), $MachinePrecision]), $MachinePrecision] + t$95$0), $MachinePrecision] / N[(N[(2.0 * a), $MachinePrecision] * N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := c \cdot \left(a \cdot 4\right)\\
\frac{\left({\left(-b\right)}^{2} - b \cdot b\right) + t_0}{\left(2 \cdot a\right) \cdot \left(\left(-b\right) - \sqrt{b \cdot b - t_0}\right)}
\end{array}
\end{array}
Initial program 17.2%
flip-+17.2%
pow217.2%
add-sqr-sqrt17.7%
*-commutative17.7%
*-commutative17.7%
*-commutative17.7%
*-commutative17.7%
Applied egg-rr17.7%
*-un-lft-identity17.7%
associate-/l/17.7%
associate--r-99.4%
*-commutative99.4%
Applied egg-rr99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (/ (/ (* 4.0 (* c a)) (- (- b) (sqrt (- (* b b) (* c (* a 4.0)))))) (* 2.0 a)))
double code(double a, double b, double c) {
return ((4.0 * (c * a)) / (-b - sqrt(((b * b) - (c * (a * 4.0)))))) / (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 = ((4.0d0 * (c * a)) / (-b - sqrt(((b * b) - (c * (a * 4.0d0)))))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return ((4.0 * (c * a)) / (-b - Math.sqrt(((b * b) - (c * (a * 4.0)))))) / (2.0 * a);
}
def code(a, b, c): return ((4.0 * (c * a)) / (-b - math.sqrt(((b * b) - (c * (a * 4.0)))))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(4.0 * Float64(c * a)) / Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = ((4.0 * (c * a)) / (-b - sqrt(((b * b) - (c * (a * 4.0)))))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[(N[(4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{4 \cdot \left(c \cdot a\right)}{\left(-b\right) - \sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)}}}{2 \cdot a}
\end{array}
Initial program 17.2%
flip-+17.2%
pow217.2%
add-sqr-sqrt17.7%
*-commutative17.7%
*-commutative17.7%
*-commutative17.7%
*-commutative17.7%
Applied egg-rr17.7%
Taylor expanded in b around 0 99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (/ (* c (* c a)) (pow b 3.0))))
double code(double a, double b, double c) {
return (-c / b) - ((c * (c * a)) / pow(b, 3.0));
}
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) - ((c * (c * a)) / (b ** 3.0d0))
end function
public static double code(double a, double b, double c) {
return (-c / b) - ((c * (c * a)) / Math.pow(b, 3.0));
}
def code(a, b, c): return (-c / b) - ((c * (c * a)) / math.pow(b, 3.0))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(Float64(c * Float64(c * a)) / (b ^ 3.0))) end
function tmp = code(a, b, c) tmp = (-c / b) - ((c * (c * a)) / (b ^ 3.0)); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(N[(c * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - \frac{c \cdot \left(c \cdot a\right)}{{b}^{3}}
\end{array}
Initial program 17.2%
neg-sub017.2%
associate-+l-17.2%
sub0-neg17.2%
neg-mul-117.2%
associate-*l/17.1%
*-commutative17.1%
associate-/r*17.1%
/-rgt-identity17.1%
metadata-eval17.1%
Simplified17.2%
Taylor expanded in b around inf 95.2%
+-commutative95.2%
mul-1-neg95.2%
unsub-neg95.2%
associate-*r/95.2%
neg-mul-195.2%
unpow295.2%
associate-*l*95.2%
Simplified95.2%
Final simplification95.2%
(FPCore (a b c) :precision binary64 (* (/ (* c (* a 4.0)) (+ b (+ b (/ (* a (* c -2.0)) b)))) (/ -0.5 a)))
double code(double a, double b, double c) {
return ((c * (a * 4.0)) / (b + (b + ((a * (c * -2.0)) / b)))) * (-0.5 / a);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((c * (a * 4.0d0)) / (b + (b + ((a * (c * (-2.0d0))) / b)))) * ((-0.5d0) / a)
end function
public static double code(double a, double b, double c) {
return ((c * (a * 4.0)) / (b + (b + ((a * (c * -2.0)) / b)))) * (-0.5 / a);
}
def code(a, b, c): return ((c * (a * 4.0)) / (b + (b + ((a * (c * -2.0)) / b)))) * (-0.5 / a)
function code(a, b, c) return Float64(Float64(Float64(c * Float64(a * 4.0)) / Float64(b + Float64(b + Float64(Float64(a * Float64(c * -2.0)) / b)))) * Float64(-0.5 / a)) end
function tmp = code(a, b, c) tmp = ((c * (a * 4.0)) / (b + (b + ((a * (c * -2.0)) / b)))) * (-0.5 / a); end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[(b + N[(N[(a * N[(c * -2.0), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-0.5 / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \left(a \cdot 4\right)}{b + \left(b + \frac{a \cdot \left(c \cdot -2\right)}{b}\right)} \cdot \frac{-0.5}{a}
\end{array}
Initial program 17.2%
neg-sub017.2%
associate-+l-17.2%
sub0-neg17.2%
neg-mul-117.2%
associate-*l/17.1%
*-commutative17.1%
associate-/r*17.1%
/-rgt-identity17.1%
metadata-eval17.1%
Simplified17.2%
Taylor expanded in a around 0 11.9%
*-commutative11.9%
associate-/l*11.9%
Simplified11.9%
flip--11.8%
*-commutative11.8%
associate-/r/11.8%
*-commutative11.8%
associate-/r/11.8%
*-commutative11.8%
associate-/r/11.8%
Applied egg-rr11.8%
difference-of-squares11.9%
associate-*l/11.9%
associate-*r/11.9%
associate-*r*11.9%
associate--r+90.3%
+-inverses90.3%
associate-*l/90.1%
neg-sub090.1%
associate-*l/90.3%
distribute-lft-neg-in90.3%
metadata-eval90.3%
*-commutative90.3%
associate-*l/90.3%
Simplified90.3%
Taylor expanded in b around inf 94.8%
*-commutative94.8%
associate-*r*94.8%
Simplified94.8%
Final simplification94.8%
(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(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 17.2%
neg-sub017.2%
associate-+l-17.2%
sub0-neg17.2%
neg-mul-117.2%
associate-*l/17.1%
*-commutative17.1%
associate-/r*17.1%
/-rgt-identity17.1%
metadata-eval17.1%
Simplified17.2%
Taylor expanded in b around inf 90.6%
associate-*r/90.6%
neg-mul-190.6%
Simplified90.6%
Final simplification90.6%
herbie shell --seed 2023178
(FPCore (a b c)
:name "Quadratic roots, wide range"
:precision binary64
:pre (and (and (and (< 4.930380657631324e-32 a) (< a 2.028240960365167e+31)) (and (< 4.930380657631324e-32 b) (< b 2.028240960365167e+31))) (and (< 4.930380657631324e-32 c) (< c 2.028240960365167e+31)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))