
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * 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) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * 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) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\end{array}
(FPCore (a b c) :precision binary64 (let* ((t_0 (* c (* a -3.0)))) (- (/ (/ t_0 (- (- b) (sqrt (+ t_0 (* b b))))) (* a 3.0)))))
double code(double a, double b, double c) {
double t_0 = c * (a * -3.0);
return -((t_0 / (-b - sqrt((t_0 + (b * b))))) / (a * 3.0));
}
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 * (-3.0d0))
code = -((t_0 / (-b - sqrt((t_0 + (b * b))))) / (a * 3.0d0))
end function
public static double code(double a, double b, double c) {
double t_0 = c * (a * -3.0);
return -((t_0 / (-b - Math.sqrt((t_0 + (b * b))))) / (a * 3.0));
}
def code(a, b, c): t_0 = c * (a * -3.0) return -((t_0 / (-b - math.sqrt((t_0 + (b * b))))) / (a * 3.0))
function code(a, b, c) t_0 = Float64(c * Float64(a * -3.0)) return Float64(-Float64(Float64(t_0 / Float64(Float64(-b) - sqrt(Float64(t_0 + Float64(b * b))))) / Float64(a * 3.0))) end
function tmp = code(a, b, c) t_0 = c * (a * -3.0); tmp = -((t_0 / (-b - sqrt((t_0 + (b * b))))) / (a * 3.0)); end
code[a_, b_, c_] := Block[{t$95$0 = N[(c * N[(a * -3.0), $MachinePrecision]), $MachinePrecision]}, (-N[(N[(t$95$0 / N[((-b) - N[Sqrt[N[(t$95$0 + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision])]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := c \cdot \left(a \cdot -3\right)\\
-\frac{\frac{t_0}{\left(-b\right) - \sqrt{t_0 + b \cdot b}}}{a \cdot 3}
\end{array}
\end{array}
Initial program 17.8%
Taylor expanded in a around 0 17.7%
*-commutative17.7%
*-commutative17.7%
associate-*l*17.8%
Simplified17.8%
flip-+17.8%
add-sqr-sqrt18.2%
associate-*r*18.3%
*-commutative18.3%
associate-*r*18.3%
*-commutative18.3%
Applied egg-rr18.3%
sqr-neg18.3%
sub-neg18.3%
associate--r+99.2%
+-inverses99.2%
distribute-rgt-neg-in99.2%
metadata-eval99.2%
associate-*l*99.5%
sub-neg99.5%
+-commutative99.5%
sqr-neg99.5%
distribute-rgt-neg-out99.5%
unsub-neg99.5%
distribute-rgt-neg-in99.5%
metadata-eval99.5%
associate-*l*99.5%
fma-neg99.5%
distribute-rgt-neg-out99.5%
sqr-neg99.5%
Simplified99.5%
fma-udef99.5%
Applied egg-rr99.5%
Final simplification99.5%
(FPCore (a b c) :precision binary64 (/ (/ (* -3.0 (* c (- a))) (- (- b) (sqrt (+ (* c (* a -3.0)) (* b b))))) (* a 3.0)))
double code(double a, double b, double c) {
return ((-3.0 * (c * -a)) / (-b - sqrt(((c * (a * -3.0)) + (b * b))))) / (a * 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 = (((-3.0d0) * (c * -a)) / (-b - sqrt(((c * (a * (-3.0d0))) + (b * b))))) / (a * 3.0d0)
end function
public static double code(double a, double b, double c) {
return ((-3.0 * (c * -a)) / (-b - Math.sqrt(((c * (a * -3.0)) + (b * b))))) / (a * 3.0);
}
def code(a, b, c): return ((-3.0 * (c * -a)) / (-b - math.sqrt(((c * (a * -3.0)) + (b * b))))) / (a * 3.0)
function code(a, b, c) return Float64(Float64(Float64(-3.0 * Float64(c * Float64(-a))) / Float64(Float64(-b) - sqrt(Float64(Float64(c * Float64(a * -3.0)) + Float64(b * b))))) / Float64(a * 3.0)) end
function tmp = code(a, b, c) tmp = ((-3.0 * (c * -a)) / (-b - sqrt(((c * (a * -3.0)) + (b * b))))) / (a * 3.0); end
code[a_, b_, c_] := N[(N[(N[(-3.0 * N[(c * (-a)), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(c * N[(a * -3.0), $MachinePrecision]), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{-3 \cdot \left(c \cdot \left(-a\right)\right)}{\left(-b\right) - \sqrt{c \cdot \left(a \cdot -3\right) + b \cdot b}}}{a \cdot 3}
\end{array}
Initial program 17.8%
Taylor expanded in a around 0 17.7%
*-commutative17.7%
*-commutative17.7%
associate-*l*17.8%
Simplified17.8%
flip-+17.8%
add-sqr-sqrt18.2%
associate-*r*18.3%
*-commutative18.3%
associate-*r*18.3%
*-commutative18.3%
Applied egg-rr18.3%
sqr-neg18.3%
sub-neg18.3%
associate--r+99.2%
+-inverses99.2%
distribute-rgt-neg-in99.2%
metadata-eval99.2%
associate-*l*99.5%
sub-neg99.5%
+-commutative99.5%
sqr-neg99.5%
distribute-rgt-neg-out99.5%
unsub-neg99.5%
distribute-rgt-neg-in99.5%
metadata-eval99.5%
associate-*l*99.5%
fma-neg99.5%
distribute-rgt-neg-out99.5%
sqr-neg99.5%
Simplified99.5%
fma-udef99.5%
Applied egg-rr99.5%
Taylor expanded in c around 0 99.2%
Final simplification99.2%
(FPCore (a b c) :precision binary64 (+ (* -0.375 (* a (/ (* c c) (pow b 3.0)))) (* -0.5 (/ c b))))
double code(double a, double b, double c) {
return (-0.375 * (a * ((c * c) / pow(b, 3.0)))) + (-0.5 * (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 = ((-0.375d0) * (a * ((c * c) / (b ** 3.0d0)))) + ((-0.5d0) * (c / b))
end function
public static double code(double a, double b, double c) {
return (-0.375 * (a * ((c * c) / Math.pow(b, 3.0)))) + (-0.5 * (c / b));
}
def code(a, b, c): return (-0.375 * (a * ((c * c) / math.pow(b, 3.0)))) + (-0.5 * (c / b))
function code(a, b, c) return Float64(Float64(-0.375 * Float64(a * Float64(Float64(c * c) / (b ^ 3.0)))) + Float64(-0.5 * Float64(c / b))) end
function tmp = code(a, b, c) tmp = (-0.375 * (a * ((c * c) / (b ^ 3.0)))) + (-0.5 * (c / b)); end
code[a_, b_, c_] := N[(N[(-0.375 * N[(a * N[(N[(c * c), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.375 \cdot \left(a \cdot \frac{c \cdot c}{{b}^{3}}\right) + -0.5 \cdot \frac{c}{b}
\end{array}
Initial program 17.8%
/-rgt-identity17.8%
metadata-eval17.8%
associate-/l*17.8%
associate-*r/17.8%
*-commutative17.8%
associate-*l/17.8%
associate-*r/17.8%
metadata-eval17.8%
metadata-eval17.8%
times-frac17.8%
neg-mul-117.8%
distribute-rgt-neg-in17.8%
times-frac17.8%
metadata-eval17.8%
neg-mul-117.8%
Simplified17.8%
Taylor expanded in b around inf 95.4%
+-commutative95.4%
fma-def95.4%
associate-/l*95.4%
unpow295.4%
Simplified95.4%
fma-udef95.4%
associate-/r/95.4%
Applied egg-rr95.4%
Final simplification95.4%
(FPCore (a b c) :precision binary64 (* -0.5 (/ c b)))
double code(double a, double b, double c) {
return -0.5 * (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 = (-0.5d0) * (c / b)
end function
public static double code(double a, double b, double c) {
return -0.5 * (c / b);
}
def code(a, b, c): return -0.5 * (c / b)
function code(a, b, c) return Float64(-0.5 * Float64(c / b)) end
function tmp = code(a, b, c) tmp = -0.5 * (c / b); end
code[a_, b_, c_] := N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.5 \cdot \frac{c}{b}
\end{array}
Initial program 17.8%
/-rgt-identity17.8%
metadata-eval17.8%
associate-/l*17.8%
associate-*r/17.8%
*-commutative17.8%
associate-*l/17.8%
associate-*r/17.8%
metadata-eval17.8%
metadata-eval17.8%
times-frac17.8%
neg-mul-117.8%
distribute-rgt-neg-in17.8%
times-frac17.8%
metadata-eval17.8%
neg-mul-117.8%
Simplified17.8%
Taylor expanded in b around inf 90.4%
Final simplification90.4%
herbie shell --seed 2023229
(FPCore (a b c)
:name "Cubic critical, 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) (* (* 3.0 a) c)))) (* 3.0 a)))