
(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
(let* ((t_0 (* c (* a 3.0))))
(/
(/
(- (- (pow b 2.0) (pow (- b) 2.0)) t_0)
(+ b (sqrt (- (pow b 2.0) t_0))))
(* a 3.0))))
double code(double a, double b, double c) {
double t_0 = c * (a * 3.0);
return (((pow(b, 2.0) - pow(-b, 2.0)) - t_0) / (b + sqrt((pow(b, 2.0) - 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 = c * (a * 3.0d0)
code = ((((b ** 2.0d0) - (-b ** 2.0d0)) - t_0) / (b + sqrt(((b ** 2.0d0) - t_0)))) / (a * 3.0d0)
end function
public static double code(double a, double b, double c) {
double t_0 = c * (a * 3.0);
return (((Math.pow(b, 2.0) - Math.pow(-b, 2.0)) - t_0) / (b + Math.sqrt((Math.pow(b, 2.0) - t_0)))) / (a * 3.0);
}
def code(a, b, c): t_0 = c * (a * 3.0) return (((math.pow(b, 2.0) - math.pow(-b, 2.0)) - t_0) / (b + math.sqrt((math.pow(b, 2.0) - t_0)))) / (a * 3.0)
function code(a, b, c) t_0 = Float64(c * Float64(a * 3.0)) return Float64(Float64(Float64(Float64((b ^ 2.0) - (Float64(-b) ^ 2.0)) - t_0) / Float64(b + sqrt(Float64((b ^ 2.0) - t_0)))) / Float64(a * 3.0)) end
function tmp = code(a, b, c) t_0 = c * (a * 3.0); tmp = ((((b ^ 2.0) - (-b ^ 2.0)) - t_0) / (b + sqrt(((b ^ 2.0) - t_0)))) / (a * 3.0); end
code[a_, b_, c_] := Block[{t$95$0 = N[(c * N[(a * 3.0), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(N[Power[b, 2.0], $MachinePrecision] - N[Power[(-b), 2.0], $MachinePrecision]), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(b + N[Sqrt[N[(N[Power[b, 2.0], $MachinePrecision] - t$95$0), $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{\left({b}^{2} - {\left(-b\right)}^{2}\right) - t\_0}{b + \sqrt{{b}^{2} - t\_0}}}{a \cdot 3}
\end{array}
\end{array}
Initial program 28.7%
add-cbrt-cube28.7%
pow328.7%
Applied egg-rr28.7%
flip-+28.8%
pow228.8%
add-sqr-sqrt29.6%
pow229.6%
*-commutative29.6%
*-commutative29.6%
pow229.6%
*-commutative29.6%
*-commutative29.6%
Applied egg-rr29.6%
associate--r-99.0%
Simplified99.0%
Taylor expanded in a around 0 99.4%
*-commutative99.4%
Simplified99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (/ (/ (* c (* a 3.0)) (- (- b) (sqrt (fma b b (* c (* a -3.0)))))) (* a 3.0)))
double code(double a, double b, double c) {
return ((c * (a * 3.0)) / (-b - sqrt(fma(b, b, (c * (a * -3.0)))))) / (a * 3.0);
}
function code(a, b, c) return Float64(Float64(Float64(c * Float64(a * 3.0)) / Float64(Float64(-b) - sqrt(fma(b, b, Float64(c * Float64(a * -3.0)))))) / Float64(a * 3.0)) end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * 3.0), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(b * b + N[(c * N[(a * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{a \cdot 3}
\end{array}
Initial program 28.7%
add-cbrt-cube28.7%
pow328.7%
Applied egg-rr28.7%
flip-+28.8%
pow228.8%
add-sqr-sqrt29.6%
pow229.6%
*-commutative29.6%
*-commutative29.6%
pow229.6%
*-commutative29.6%
*-commutative29.6%
Applied egg-rr29.6%
associate--r-99.0%
Simplified99.0%
Taylor expanded in a around 0 99.4%
*-commutative99.4%
Simplified99.4%
div-inv99.2%
+-commutative99.2%
*-commutative99.2%
fma-define99.2%
*-commutative99.2%
neg-mul-199.2%
unpow-prod-down99.2%
metadata-eval99.2%
*-un-lft-identity99.2%
Applied egg-rr99.2%
associate-*r/99.4%
*-rgt-identity99.4%
fma-undefine99.4%
+-inverses99.4%
+-rgt-identity99.4%
unpow299.4%
fmm-def99.4%
distribute-rgt-neg-in99.4%
*-commutative99.4%
distribute-lft-neg-in99.4%
metadata-eval99.4%
*-commutative99.4%
Simplified99.4%
(FPCore (a b c) :precision binary64 (/ (+ (* c -0.5) (* (* a -0.375) (pow (/ b c) -2.0))) b))
double code(double a, double b, double c) {
return ((c * -0.5) + ((a * -0.375) * pow((b / c), -2.0))) / 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)) + ((a * (-0.375d0)) * ((b / c) ** (-2.0d0)))) / b
end function
public static double code(double a, double b, double c) {
return ((c * -0.5) + ((a * -0.375) * Math.pow((b / c), -2.0))) / b;
}
def code(a, b, c): return ((c * -0.5) + ((a * -0.375) * math.pow((b / c), -2.0))) / b
function code(a, b, c) return Float64(Float64(Float64(c * -0.5) + Float64(Float64(a * -0.375) * (Float64(b / c) ^ -2.0))) / b) end
function tmp = code(a, b, c) tmp = ((c * -0.5) + ((a * -0.375) * ((b / c) ^ -2.0))) / b; end
code[a_, b_, c_] := N[(N[(N[(c * -0.5), $MachinePrecision] + N[(N[(a * -0.375), $MachinePrecision] * N[Power[N[(b / c), $MachinePrecision], -2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot -0.5 + \left(a \cdot -0.375\right) \cdot {\left(\frac{b}{c}\right)}^{-2}}{b}
\end{array}
Initial program 28.7%
add-cbrt-cube28.7%
pow328.7%
Applied egg-rr28.7%
Taylor expanded in b around inf 91.8%
fma-define91.8%
associate-/l*91.8%
unpow291.8%
unpow291.8%
times-frac91.8%
unpow191.8%
pow-plus91.8%
metadata-eval91.8%
Simplified91.8%
fma-undefine91.8%
associate-*r*91.8%
clear-num91.8%
inv-pow91.8%
pow-pow91.8%
metadata-eval91.8%
Applied egg-rr91.8%
Final simplification91.8%
(FPCore (a b c) :precision binary64 (/ (* c (- (* -0.375 (/ (* c a) (pow b 2.0))) 0.5)) b))
double code(double a, double b, double c) {
return (c * ((-0.375 * ((c * a) / pow(b, 2.0))) - 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 * (((-0.375d0) * ((c * a) / (b ** 2.0d0))) - 0.5d0)) / b
end function
public static double code(double a, double b, double c) {
return (c * ((-0.375 * ((c * a) / Math.pow(b, 2.0))) - 0.5)) / b;
}
def code(a, b, c): return (c * ((-0.375 * ((c * a) / math.pow(b, 2.0))) - 0.5)) / b
function code(a, b, c) return Float64(Float64(c * Float64(Float64(-0.375 * Float64(Float64(c * a) / (b ^ 2.0))) - 0.5)) / b) end
function tmp = code(a, b, c) tmp = (c * ((-0.375 * ((c * a) / (b ^ 2.0))) - 0.5)) / b; end
code[a_, b_, c_] := N[(N[(c * N[(N[(-0.375 * N[(N[(c * a), $MachinePrecision] / N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \left(-0.375 \cdot \frac{c \cdot a}{{b}^{2}} - 0.5\right)}{b}
\end{array}
Initial program 28.7%
add-cbrt-cube28.7%
pow328.7%
Applied egg-rr28.7%
Taylor expanded in b around inf 91.8%
fma-define91.8%
associate-/l*91.8%
unpow291.8%
unpow291.8%
times-frac91.8%
unpow191.8%
pow-plus91.8%
metadata-eval91.8%
Simplified91.8%
Taylor expanded in c around 0 91.8%
Final simplification91.8%
(FPCore (a b c) :precision binary64 (* c (- (* -0.375 (* a (/ c (pow b 3.0)))) (/ 0.5 b))))
double code(double a, double b, double c) {
return c * ((-0.375 * (a * (c / pow(b, 3.0)))) - (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 * (((-0.375d0) * (a * (c / (b ** 3.0d0)))) - (0.5d0 / b))
end function
public static double code(double a, double b, double c) {
return c * ((-0.375 * (a * (c / Math.pow(b, 3.0)))) - (0.5 / b));
}
def code(a, b, c): return c * ((-0.375 * (a * (c / math.pow(b, 3.0)))) - (0.5 / b))
function code(a, b, c) return Float64(c * Float64(Float64(-0.375 * Float64(a * Float64(c / (b ^ 3.0)))) - Float64(0.5 / b))) end
function tmp = code(a, b, c) tmp = c * ((-0.375 * (a * (c / (b ^ 3.0)))) - (0.5 / b)); end
code[a_, b_, c_] := N[(c * N[(N[(-0.375 * N[(a * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \left(-0.375 \cdot \left(a \cdot \frac{c}{{b}^{3}}\right) - \frac{0.5}{b}\right)
\end{array}
Initial program 28.7%
Simplified28.7%
Taylor expanded in c around 0 91.6%
associate-/l*91.6%
associate-*r/91.6%
metadata-eval91.6%
Simplified91.6%
(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 28.7%
Simplified28.7%
Taylor expanded in b around inf 83.0%
herbie shell --seed 2024180
(FPCore (a b c)
:name "Cubic critical, medium range"
:precision binary64
:pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))