
(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 6 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
(/
1.0
(*
(/ a (* a c))
(-
(- b)
(sqrt
(* (fma (sqrt a) (sqrt (* c 3.0)) b) (- b (sqrt (* a (* c 3.0))))))))))
double code(double a, double b, double c) {
return 1.0 / ((a / (a * c)) * (-b - sqrt((fma(sqrt(a), sqrt((c * 3.0)), b) * (b - sqrt((a * (c * 3.0))))))));
}
function code(a, b, c) return Float64(1.0 / Float64(Float64(a / Float64(a * c)) * Float64(Float64(-b) - sqrt(Float64(fma(sqrt(a), sqrt(Float64(c * 3.0)), b) * Float64(b - sqrt(Float64(a * Float64(c * 3.0))))))))) end
code[a_, b_, c_] := N[(1.0 / N[(N[(a / N[(a * c), $MachinePrecision]), $MachinePrecision] * N[((-b) - N[Sqrt[N[(N[(N[Sqrt[a], $MachinePrecision] * N[Sqrt[N[(c * 3.0), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision] * N[(b - N[Sqrt[N[(a * N[(c * 3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{a}{a \cdot c} \cdot \left(\left(-b\right) - \sqrt{\mathsf{fma}\left(\sqrt{a}, \sqrt{c \cdot 3}, b\right) \cdot \left(b - \sqrt{a \cdot \left(c \cdot 3\right)}\right)}\right)}
\end{array}
Initial program 19.1%
add-sqr-sqrt19.1%
difference-of-squares19.2%
associate-*l*19.2%
associate-*l*19.2%
Applied egg-rr19.2%
associate-*r*19.2%
*-commutative19.2%
associate-*r*19.2%
*-commutative19.2%
Simplified19.2%
flip-+19.1%
Applied egg-rr19.4%
unpow219.4%
sqr-neg19.4%
unpow219.4%
associate-*r*19.4%
*-commutative19.4%
associate-*r*19.4%
associate-*r*19.4%
*-commutative19.4%
associate-*r*19.4%
Simplified19.4%
Taylor expanded in b around 0 98.6%
+-commutative98.6%
fma-define98.6%
unpow298.6%
rem-square-sqrt99.3%
*-commutative99.3%
distribute-lft1-in99.3%
metadata-eval99.3%
mul0-lft99.3%
mul0-lft99.3%
metadata-eval99.3%
Simplified99.3%
clear-num99.1%
inv-pow99.1%
*-commutative99.1%
+-commutative99.1%
sqrt-prod99.1%
fma-define99.1%
Applied egg-rr99.1%
unpow-199.1%
associate-/r/99.1%
*-commutative99.1%
fma-define99.1%
+-rgt-identity99.1%
associate-*r*99.1%
*-commutative99.1%
times-frac99.3%
metadata-eval99.3%
*-commutative99.3%
Simplified99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (let* ((t_0 (sqrt (* a (* c 3.0))))) (/ (/ (* 3.0 (* a c)) (- (- b) (sqrt (* (- b t_0) (+ b t_0))))) (* a 3.0))))
double code(double a, double b, double c) {
double t_0 = sqrt((a * (c * 3.0)));
return ((3.0 * (a * c)) / (-b - sqrt(((b - t_0) * (b + t_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
real(8) :: t_0
t_0 = sqrt((a * (c * 3.0d0)))
code = ((3.0d0 * (a * c)) / (-b - sqrt(((b - t_0) * (b + t_0))))) / (a * 3.0d0)
end function
public static double code(double a, double b, double c) {
double t_0 = Math.sqrt((a * (c * 3.0)));
return ((3.0 * (a * c)) / (-b - Math.sqrt(((b - t_0) * (b + t_0))))) / (a * 3.0);
}
def code(a, b, c): t_0 = math.sqrt((a * (c * 3.0))) return ((3.0 * (a * c)) / (-b - math.sqrt(((b - t_0) * (b + t_0))))) / (a * 3.0)
function code(a, b, c) t_0 = sqrt(Float64(a * Float64(c * 3.0))) return Float64(Float64(Float64(3.0 * Float64(a * c)) / Float64(Float64(-b) - sqrt(Float64(Float64(b - t_0) * Float64(b + t_0))))) / Float64(a * 3.0)) end
function tmp = code(a, b, c) t_0 = sqrt((a * (c * 3.0))); tmp = ((3.0 * (a * c)) / (-b - sqrt(((b - t_0) * (b + t_0))))) / (a * 3.0); end
code[a_, b_, c_] := Block[{t$95$0 = N[Sqrt[N[(a * N[(c * 3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(3.0 * N[(a * c), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(b - t$95$0), $MachinePrecision] * N[(b + t$95$0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{a \cdot \left(c \cdot 3\right)}\\
\frac{\frac{3 \cdot \left(a \cdot c\right)}{\left(-b\right) - \sqrt{\left(b - t\_0\right) \cdot \left(b + t\_0\right)}}}{a \cdot 3}
\end{array}
\end{array}
Initial program 19.1%
add-sqr-sqrt19.1%
difference-of-squares19.2%
associate-*l*19.2%
associate-*l*19.2%
Applied egg-rr19.2%
associate-*r*19.2%
*-commutative19.2%
associate-*r*19.2%
*-commutative19.2%
Simplified19.2%
flip-+19.1%
Applied egg-rr19.4%
unpow219.4%
sqr-neg19.4%
unpow219.4%
associate-*r*19.4%
*-commutative19.4%
associate-*r*19.4%
associate-*r*19.4%
*-commutative19.4%
associate-*r*19.4%
Simplified19.4%
Taylor expanded in b around 0 98.6%
+-commutative98.6%
fma-define98.6%
unpow298.6%
rem-square-sqrt99.3%
*-commutative99.3%
distribute-lft1-in99.3%
metadata-eval99.3%
mul0-lft99.3%
mul0-lft99.3%
metadata-eval99.3%
Simplified99.3%
Taylor expanded in a around 0 99.2%
Final simplification99.2%
(FPCore (a b c) :precision binary64 (let* ((t_0 (* a (* c 3.0))) (t_1 (sqrt t_0))) (/ (/ t_0 (- (- b) (sqrt (* (- b t_1) (+ b t_1))))) (* a 3.0))))
double code(double a, double b, double c) {
double t_0 = a * (c * 3.0);
double t_1 = sqrt(t_0);
return (t_0 / (-b - sqrt(((b - t_1) * (b + t_1))))) / (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
real(8) :: t_1
t_0 = a * (c * 3.0d0)
t_1 = sqrt(t_0)
code = (t_0 / (-b - sqrt(((b - t_1) * (b + t_1))))) / (a * 3.0d0)
end function
public static double code(double a, double b, double c) {
double t_0 = a * (c * 3.0);
double t_1 = Math.sqrt(t_0);
return (t_0 / (-b - Math.sqrt(((b - t_1) * (b + t_1))))) / (a * 3.0);
}
def code(a, b, c): t_0 = a * (c * 3.0) t_1 = math.sqrt(t_0) return (t_0 / (-b - math.sqrt(((b - t_1) * (b + t_1))))) / (a * 3.0)
function code(a, b, c) t_0 = Float64(a * Float64(c * 3.0)) t_1 = sqrt(t_0) return Float64(Float64(t_0 / Float64(Float64(-b) - sqrt(Float64(Float64(b - t_1) * Float64(b + t_1))))) / Float64(a * 3.0)) end
function tmp = code(a, b, c) t_0 = a * (c * 3.0); t_1 = sqrt(t_0); tmp = (t_0 / (-b - sqrt(((b - t_1) * (b + t_1))))) / (a * 3.0); end
code[a_, b_, c_] := Block[{t$95$0 = N[(a * N[(c * 3.0), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[Sqrt[t$95$0], $MachinePrecision]}, N[(N[(t$95$0 / N[((-b) - N[Sqrt[N[(N[(b - t$95$1), $MachinePrecision] * N[(b + t$95$1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := a \cdot \left(c \cdot 3\right)\\
t_1 := \sqrt{t\_0}\\
\frac{\frac{t\_0}{\left(-b\right) - \sqrt{\left(b - t\_1\right) \cdot \left(b + t\_1\right)}}}{a \cdot 3}
\end{array}
\end{array}
Initial program 19.1%
add-sqr-sqrt19.1%
difference-of-squares19.2%
associate-*l*19.2%
associate-*l*19.2%
Applied egg-rr19.2%
associate-*r*19.2%
*-commutative19.2%
associate-*r*19.2%
*-commutative19.2%
Simplified19.2%
flip-+19.1%
Applied egg-rr19.4%
unpow219.4%
sqr-neg19.4%
unpow219.4%
associate-*r*19.4%
*-commutative19.4%
associate-*r*19.4%
associate-*r*19.4%
*-commutative19.4%
associate-*r*19.4%
Simplified19.4%
Taylor expanded in b around 0 98.6%
+-commutative98.6%
fma-define98.6%
unpow298.6%
rem-square-sqrt99.3%
*-commutative99.3%
distribute-lft1-in99.3%
metadata-eval99.3%
mul0-lft99.3%
mul0-lft99.3%
metadata-eval99.3%
Simplified99.3%
Taylor expanded in a around 0 99.2%
*-commutative99.2%
associate-*r*99.3%
Simplified99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (+ (* -0.5 (/ c b)) (* -0.375 (/ (* a (pow c 2.0)) (pow b 3.0)))))
double code(double a, double b, double c) {
return (-0.5 * (c / b)) + (-0.375 * ((a * pow(c, 2.0)) / 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 = ((-0.5d0) * (c / b)) + ((-0.375d0) * ((a * (c ** 2.0d0)) / (b ** 3.0d0)))
end function
public static double code(double a, double b, double c) {
return (-0.5 * (c / b)) + (-0.375 * ((a * Math.pow(c, 2.0)) / Math.pow(b, 3.0)));
}
def code(a, b, c): return (-0.5 * (c / b)) + (-0.375 * ((a * math.pow(c, 2.0)) / math.pow(b, 3.0)))
function code(a, b, c) return Float64(Float64(-0.5 * Float64(c / b)) + Float64(-0.375 * Float64(Float64(a * (c ^ 2.0)) / (b ^ 3.0)))) end
function tmp = code(a, b, c) tmp = (-0.5 * (c / b)) + (-0.375 * ((a * (c ^ 2.0)) / (b ^ 3.0))); end
code[a_, b_, c_] := N[(N[(-0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision] + N[(-0.375 * N[(N[(a * N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-0.5 \cdot \frac{c}{b} + -0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}
\end{array}
Initial program 19.1%
Taylor expanded in b around inf 95.8%
Final simplification95.8%
(FPCore (a b c) :precision binary64 (/ (* c -0.5) b))
double code(double a, double b, double c) {
return (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 = (c * (-0.5d0)) / b
end function
public static double code(double a, double b, double c) {
return (c * -0.5) / b;
}
def code(a, b, c): return (c * -0.5) / b
function code(a, b, c) return Float64(Float64(c * -0.5) / b) end
function tmp = code(a, b, c) tmp = (c * -0.5) / b; end
code[a_, b_, c_] := N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot -0.5}{b}
\end{array}
Initial program 19.1%
Taylor expanded in b around inf 89.7%
*-commutative89.7%
associate-*l/89.7%
Simplified89.7%
Final simplification89.7%
(FPCore (a b c) :precision binary64 (/ 0.0 a))
double code(double a, double b, double c) {
return 0.0 / a;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = 0.0d0 / a
end function
public static double code(double a, double b, double c) {
return 0.0 / a;
}
def code(a, b, c): return 0.0 / a
function code(a, b, c) return Float64(0.0 / a) end
function tmp = code(a, b, c) tmp = 0.0 / a; end
code[a_, b_, c_] := N[(0.0 / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{0}{a}
\end{array}
Initial program 19.1%
add-sqr-sqrt19.1%
difference-of-squares19.2%
associate-*l*19.2%
associate-*l*19.2%
Applied egg-rr19.2%
associate-*r*19.2%
*-commutative19.2%
associate-*r*19.2%
*-commutative19.2%
Simplified19.2%
Taylor expanded in b around inf 3.3%
associate-*r/3.3%
distribute-lft1-in3.3%
metadata-eval3.3%
mul0-lft3.3%
metadata-eval3.3%
Simplified3.3%
Final simplification3.3%
herbie shell --seed 2024041
(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)))