
(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 3 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 (/ (/ (* c (* a -3.0)) (+ b (sqrt (- (* b b) (* 3.0 (* c a)))))) (* a 3.0)))
double code(double a, double b, double c) {
return ((c * (a * -3.0)) / (b + sqrt(((b * b) - (3.0 * (c * a)))))) / (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 = ((c * (a * (-3.0d0))) / (b + sqrt(((b * b) - (3.0d0 * (c * a)))))) / (a * 3.0d0)
end function
public static double code(double a, double b, double c) {
return ((c * (a * -3.0)) / (b + Math.sqrt(((b * b) - (3.0 * (c * a)))))) / (a * 3.0);
}
def code(a, b, c): return ((c * (a * -3.0)) / (b + math.sqrt(((b * b) - (3.0 * (c * a)))))) / (a * 3.0)
function code(a, b, c) return Float64(Float64(Float64(c * Float64(a * -3.0)) / Float64(b + sqrt(Float64(Float64(b * b) - Float64(3.0 * Float64(c * a)))))) / Float64(a * 3.0)) end
function tmp = code(a, b, c) tmp = ((c * (a * -3.0)) / (b + sqrt(((b * b) - (3.0 * (c * a)))))) / (a * 3.0); end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * -3.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(3.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{c \cdot \left(a \cdot -3\right)}{b + \sqrt{b \cdot b - 3 \cdot \left(c \cdot a\right)}}}{a \cdot 3}
\end{array}
Initial program 15.8%
neg-sub015.8%
sqr-neg15.8%
associate-+l-15.8%
sub0-neg15.8%
Simplified15.9%
associate-*r*15.9%
*-commutative15.9%
metadata-eval15.9%
distribute-rgt-neg-in15.9%
*-commutative15.9%
fma-neg15.8%
Applied egg-rr15.8%
flip--15.8%
add-sqr-sqrt16.4%
Applied egg-rr16.4%
Taylor expanded in b around 0 99.2%
*-commutative99.2%
*-commutative99.2%
associate-*l*99.4%
Simplified99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (+ (* (* c (* c (/ a (pow b 3.0)))) -0.375) (* -0.5 (/ c b))))
double code(double a, double b, double c) {
return ((c * (c * (a / pow(b, 3.0)))) * -0.375) + (-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 = ((c * (c * (a / (b ** 3.0d0)))) * (-0.375d0)) + ((-0.5d0) * (c / b))
end function
public static double code(double a, double b, double c) {
return ((c * (c * (a / Math.pow(b, 3.0)))) * -0.375) + (-0.5 * (c / b));
}
def code(a, b, c): return ((c * (c * (a / math.pow(b, 3.0)))) * -0.375) + (-0.5 * (c / b))
function code(a, b, c) return Float64(Float64(Float64(c * Float64(c * Float64(a / (b ^ 3.0)))) * -0.375) + Float64(-0.5 * Float64(c / b))) end
function tmp = code(a, b, c) tmp = ((c * (c * (a / (b ^ 3.0)))) * -0.375) + (-0.5 * (c / b)); end
code[a_, b_, c_] := N[(N[(N[(c * N[(c * N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -0.375), $MachinePrecision] + N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(c \cdot \left(c \cdot \frac{a}{{b}^{3}}\right)\right) \cdot -0.375 + -0.5 \cdot \frac{c}{b}
\end{array}
Initial program 15.8%
neg-sub015.8%
sqr-neg15.8%
associate-+l-15.8%
sub0-neg15.8%
Simplified15.9%
associate-*r*15.9%
*-commutative15.9%
metadata-eval15.9%
distribute-rgt-neg-in15.9%
*-commutative15.9%
fma-neg15.8%
Applied egg-rr15.8%
flip--15.8%
add-sqr-sqrt16.4%
Applied egg-rr16.4%
Taylor expanded in b around inf 96.2%
+-commutative96.2%
*-commutative96.2%
fma-def96.2%
unpow296.2%
associate-*l/96.2%
*-commutative96.2%
associate-*l*96.2%
Simplified96.2%
fma-udef96.2%
Applied egg-rr96.2%
Final simplification96.2%
(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 15.8%
sqr-neg15.8%
sqr-neg15.8%
associate-*l*15.8%
Simplified15.8%
Taylor expanded in b around inf 91.9%
Final simplification91.9%
herbie shell --seed 2023293
(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)))