
(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 (/ (/ (* c (* a -3.0)) (* a 3.0)) (+ b (sqrt (- (* b b) (* c (* a 3.0)))))))
double code(double a, double b, double c) {
return ((c * (a * -3.0)) / (a * 3.0)) / (b + sqrt(((b * b) - (c * (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))) / (a * 3.0d0)) / (b + sqrt(((b * b) - (c * (a * 3.0d0)))))
end function
public static double code(double a, double b, double c) {
return ((c * (a * -3.0)) / (a * 3.0)) / (b + Math.sqrt(((b * b) - (c * (a * 3.0)))));
}
def code(a, b, c): return ((c * (a * -3.0)) / (a * 3.0)) / (b + math.sqrt(((b * b) - (c * (a * 3.0)))))
function code(a, b, c) return Float64(Float64(Float64(c * Float64(a * -3.0)) / Float64(a * 3.0)) / Float64(b + sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 3.0)))))) end
function tmp = code(a, b, c) tmp = ((c * (a * -3.0)) / (a * 3.0)) / (b + sqrt(((b * b) - (c * (a * 3.0))))); end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * -3.0), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{c \cdot \left(a \cdot -3\right)}{a \cdot 3}}{b + \sqrt{b \cdot b - c \cdot \left(a \cdot 3\right)}}
\end{array}
Initial program 17.5%
+-commutative17.5%
unsub-neg17.5%
*-commutative17.5%
*-commutative17.5%
Applied egg-rr17.5%
flip--17.5%
add-sqr-sqrt18.1%
associate-*r*18.1%
associate-*r*18.1%
Applied egg-rr18.1%
Taylor expanded in b around 0 99.2%
*-commutative99.2%
associate-*r*99.5%
Simplified99.5%
expm1-log1p-u83.2%
expm1-udef22.3%
associate-/l/22.3%
*-commutative22.3%
+-commutative22.3%
associate-*l*22.3%
Applied egg-rr22.3%
expm1-def83.1%
expm1-log1p99.4%
associate-/r*99.7%
Simplified99.7%
Final simplification99.7%
(FPCore (a b c) :precision binary64 (/ (/ c (/ (+ b (sqrt (- (* b b) (* c (* a 3.0))))) (* a -3.0))) (* a 3.0)))
double code(double a, double b, double c) {
return (c / ((b + sqrt(((b * b) - (c * (a * 3.0))))) / (a * -3.0))) / (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 / ((b + sqrt(((b * b) - (c * (a * 3.0d0))))) / (a * (-3.0d0)))) / (a * 3.0d0)
end function
public static double code(double a, double b, double c) {
return (c / ((b + Math.sqrt(((b * b) - (c * (a * 3.0))))) / (a * -3.0))) / (a * 3.0);
}
def code(a, b, c): return (c / ((b + math.sqrt(((b * b) - (c * (a * 3.0))))) / (a * -3.0))) / (a * 3.0)
function code(a, b, c) return Float64(Float64(c / Float64(Float64(b + sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 3.0))))) / Float64(a * -3.0))) / Float64(a * 3.0)) end
function tmp = code(a, b, c) tmp = (c / ((b + sqrt(((b * b) - (c * (a * 3.0))))) / (a * -3.0))) / (a * 3.0); end
code[a_, b_, c_] := N[(N[(c / N[(N[(b + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{c}{\frac{b + \sqrt{b \cdot b - c \cdot \left(a \cdot 3\right)}}{a \cdot -3}}}{a \cdot 3}
\end{array}
Initial program 17.5%
+-commutative17.5%
unsub-neg17.5%
*-commutative17.5%
*-commutative17.5%
Applied egg-rr17.5%
flip--17.5%
add-sqr-sqrt18.1%
associate-*r*18.1%
associate-*r*18.1%
Applied egg-rr18.1%
Taylor expanded in b around 0 99.2%
*-commutative99.2%
associate-*r*99.5%
Simplified99.5%
expm1-log1p-u88.6%
expm1-udef18.7%
+-commutative18.7%
associate-*l*18.7%
Applied egg-rr18.7%
expm1-def88.6%
expm1-log1p99.5%
associate-/l*99.4%
Simplified99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (+ (* -0.375 (* a (/ (* c c) (pow b 3.0)))) (/ (* c -0.5) b)))
double code(double a, double b, double c) {
return (-0.375 * (a * ((c * c) / pow(b, 3.0)))) + ((c * -0.5) / 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)))) + ((c * (-0.5d0)) / b)
end function
public static double code(double a, double b, double c) {
return (-0.375 * (a * ((c * c) / Math.pow(b, 3.0)))) + ((c * -0.5) / b);
}
def code(a, b, c): return (-0.375 * (a * ((c * c) / math.pow(b, 3.0)))) + ((c * -0.5) / b)
function code(a, b, c) return Float64(Float64(-0.375 * Float64(a * Float64(Float64(c * c) / (b ^ 3.0)))) + Float64(Float64(c * -0.5) / b)) end
function tmp = code(a, b, c) tmp = (-0.375 * (a * ((c * c) / (b ^ 3.0)))) + ((c * -0.5) / 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[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.375 \cdot \left(a \cdot \frac{c \cdot c}{{b}^{3}}\right) + \frac{c \cdot -0.5}{b}
\end{array}
Initial program 17.5%
/-rgt-identity17.5%
metadata-eval17.5%
associate-/l*17.5%
associate-*r/17.5%
*-commutative17.5%
associate-*l/17.5%
associate-*r/17.5%
metadata-eval17.5%
metadata-eval17.5%
times-frac17.5%
neg-mul-117.5%
distribute-rgt-neg-in17.5%
times-frac17.5%
metadata-eval17.5%
neg-mul-117.5%
Simplified17.5%
Taylor expanded in b around inf 95.7%
+-commutative95.7%
fma-def95.7%
associate-/l*95.7%
unpow295.7%
Simplified95.7%
fma-udef95.7%
associate-/r/95.7%
associate-*r/95.7%
Applied egg-rr95.7%
Final simplification95.7%
(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 17.5%
/-rgt-identity17.5%
metadata-eval17.5%
associate-/l*17.5%
associate-*r/17.5%
*-commutative17.5%
associate-*l/17.5%
associate-*r/17.5%
metadata-eval17.5%
metadata-eval17.5%
times-frac17.5%
neg-mul-117.5%
distribute-rgt-neg-in17.5%
times-frac17.5%
metadata-eval17.5%
neg-mul-117.5%
Simplified17.5%
Taylor expanded in b around inf 90.7%
Final simplification90.7%
herbie shell --seed 2023215
(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)))