
(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 7 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 (/ (/ (+ (- (pow b 2.0) (pow b 2.0)) (* (* a 3.0) c)) (- (- b) (sqrt (- (pow b 2.0) (* 3.0 (* a c)))))) (* 3.0 a)))
double code(double a, double b, double c) {
return (((pow(b, 2.0) - pow(b, 2.0)) + ((a * 3.0) * c)) / (-b - sqrt((pow(b, 2.0) - (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 ** 2.0d0) - (b ** 2.0d0)) + ((a * 3.0d0) * c)) / (-b - sqrt(((b ** 2.0d0) - (3.0d0 * (a * c)))))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (((Math.pow(b, 2.0) - Math.pow(b, 2.0)) + ((a * 3.0) * c)) / (-b - Math.sqrt((Math.pow(b, 2.0) - (3.0 * (a * c)))))) / (3.0 * a);
}
def code(a, b, c): return (((math.pow(b, 2.0) - math.pow(b, 2.0)) + ((a * 3.0) * c)) / (-b - math.sqrt((math.pow(b, 2.0) - (3.0 * (a * c)))))) / (3.0 * a)
function code(a, b, c) return Float64(Float64(Float64(Float64((b ^ 2.0) - (b ^ 2.0)) + Float64(Float64(a * 3.0) * c)) / Float64(Float64(-b) - sqrt(Float64((b ^ 2.0) - Float64(3.0 * Float64(a * c)))))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) tmp = ((((b ^ 2.0) - (b ^ 2.0)) + ((a * 3.0) * c)) / (-b - sqrt(((b ^ 2.0) - (3.0 * (a * c)))))) / (3.0 * a); end
code[a_, b_, c_] := N[(N[(N[(N[(N[Power[b, 2.0], $MachinePrecision] - N[Power[b, 2.0], $MachinePrecision]), $MachinePrecision] + N[(N[(a * 3.0), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[Power[b, 2.0], $MachinePrecision] - N[(3.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\left({b}^{2} - {b}^{2}\right) + \left(a \cdot 3\right) \cdot c}{\left(-b\right) - \sqrt{{b}^{2} - 3 \cdot \left(a \cdot c\right)}}}{3 \cdot a}
\end{array}
Initial program 55.9%
add-sqr-sqrt55.8%
pow255.8%
associate-*l*55.8%
Applied egg-rr55.8%
flip-+55.7%
pow255.8%
add-sqr-sqrt57.2%
pow257.2%
unpow257.2%
add-sqr-sqrt57.2%
pow257.2%
unpow257.2%
add-sqr-sqrt57.2%
Applied egg-rr57.2%
associate--r-99.1%
neg-mul-199.1%
unpow-prod-down99.1%
metadata-eval99.1%
*-un-lft-identity99.1%
associate-*r*99.3%
*-commutative99.3%
Applied egg-rr99.3%
(FPCore (a b c) :precision binary64 (let* ((t_0 (* 3.0 (* a c)))) (/ (/ t_0 (- (- b) (sqrt (- (pow b 2.0) t_0)))) (* 3.0 a))))
double code(double a, double b, double c) {
double t_0 = 3.0 * (a * c);
return (t_0 / (-b - sqrt((pow(b, 2.0) - t_0)))) / (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
real(8) :: t_0
t_0 = 3.0d0 * (a * c)
code = (t_0 / (-b - sqrt(((b ** 2.0d0) - t_0)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
double t_0 = 3.0 * (a * c);
return (t_0 / (-b - Math.sqrt((Math.pow(b, 2.0) - t_0)))) / (3.0 * a);
}
def code(a, b, c): t_0 = 3.0 * (a * c) return (t_0 / (-b - math.sqrt((math.pow(b, 2.0) - t_0)))) / (3.0 * a)
function code(a, b, c) t_0 = Float64(3.0 * Float64(a * c)) return Float64(Float64(t_0 / Float64(Float64(-b) - sqrt(Float64((b ^ 2.0) - t_0)))) / Float64(3.0 * a)) end
function tmp = code(a, b, c) t_0 = 3.0 * (a * c); tmp = (t_0 / (-b - sqrt(((b ^ 2.0) - t_0)))) / (3.0 * a); end
code[a_, b_, c_] := Block[{t$95$0 = N[(3.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$0 / N[((-b) - N[Sqrt[N[(N[Power[b, 2.0], $MachinePrecision] - t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 3 \cdot \left(a \cdot c\right)\\
\frac{\frac{t\_0}{\left(-b\right) - \sqrt{{b}^{2} - t\_0}}}{3 \cdot a}
\end{array}
\end{array}
Initial program 55.9%
add-sqr-sqrt55.8%
pow255.8%
associate-*l*55.8%
Applied egg-rr55.8%
flip-+55.7%
pow255.8%
add-sqr-sqrt57.2%
pow257.2%
unpow257.2%
add-sqr-sqrt57.2%
pow257.2%
unpow257.2%
add-sqr-sqrt57.2%
Applied egg-rr57.2%
Taylor expanded in b around 0 99.1%
(FPCore (a b c) :precision binary64 (if (<= b 2.55) (/ (- (sqrt (fma b b (* -3.0 (* a c)))) b) (* 3.0 a)) (+ (* -0.5 (/ c b)) (* -0.375 (/ (* a (pow c 2.0)) (pow b 3.0))))))
double code(double a, double b, double c) {
double tmp;
if (b <= 2.55) {
tmp = (sqrt(fma(b, b, (-3.0 * (a * c)))) - b) / (3.0 * a);
} else {
tmp = (-0.5 * (c / b)) + (-0.375 * ((a * pow(c, 2.0)) / pow(b, 3.0)));
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 2.55) tmp = Float64(Float64(sqrt(fma(b, b, Float64(-3.0 * Float64(a * c)))) - b) / Float64(3.0 * a)); else tmp = Float64(Float64(-0.5 * Float64(c / b)) + Float64(-0.375 * Float64(Float64(a * (c ^ 2.0)) / (b ^ 3.0)))); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 2.55], N[(N[(N[Sqrt[N[(b * b + N[(-3.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision], 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}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 2.55:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, -3 \cdot \left(a \cdot c\right)\right)} - b}{3 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;-0.5 \cdot \frac{c}{b} + -0.375 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}\\
\end{array}
\end{array}
if b < 2.5499999999999998Initial program 82.7%
/-rgt-identity82.7%
metadata-eval82.7%
Simplified82.8%
Taylor expanded in a around 0 82.8%
if 2.5499999999999998 < b Initial program 49.3%
Taylor expanded in a around 0 88.5%
(FPCore (a b c) :precision binary64 (if (<= b 2.5) (/ (- (sqrt (fma b b (* -3.0 (* a c)))) b) (* 3.0 a)) (* c (- (* -0.375 (/ (* a c) (pow b 3.0))) (* 0.5 (/ 1.0 b))))))
double code(double a, double b, double c) {
double tmp;
if (b <= 2.5) {
tmp = (sqrt(fma(b, b, (-3.0 * (a * c)))) - b) / (3.0 * a);
} else {
tmp = c * ((-0.375 * ((a * c) / pow(b, 3.0))) - (0.5 * (1.0 / b)));
}
return tmp;
}
function code(a, b, c) tmp = 0.0 if (b <= 2.5) tmp = Float64(Float64(sqrt(fma(b, b, Float64(-3.0 * Float64(a * c)))) - b) / Float64(3.0 * a)); else tmp = Float64(c * Float64(Float64(-0.375 * Float64(Float64(a * c) / (b ^ 3.0))) - Float64(0.5 * Float64(1.0 / b)))); end return tmp end
code[a_, b_, c_] := If[LessEqual[b, 2.5], N[(N[(N[Sqrt[N[(b * b + N[(-3.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision], N[(c * N[(N[(-0.375 * N[(N[(a * c), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 * N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 2.5:\\
\;\;\;\;\frac{\sqrt{\mathsf{fma}\left(b, b, -3 \cdot \left(a \cdot c\right)\right)} - b}{3 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right)\\
\end{array}
\end{array}
if b < 2.5Initial program 82.7%
/-rgt-identity82.7%
metadata-eval82.7%
Simplified82.8%
Taylor expanded in a around 0 82.8%
if 2.5 < b Initial program 49.3%
Taylor expanded in c around 0 88.3%
(FPCore (a b c) :precision binary64 (if (<= b 2.5) (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)) (* c (- (* -0.375 (/ (* a c) (pow b 3.0))) (* 0.5 (/ 1.0 b))))))
double code(double a, double b, double c) {
double tmp;
if (b <= 2.5) {
tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
} else {
tmp = c * ((-0.375 * ((a * c) / pow(b, 3.0))) - (0.5 * (1.0 / b)));
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= 2.5d0) then
tmp = (-b + sqrt(((b * b) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
else
tmp = c * (((-0.375d0) * ((a * c) / (b ** 3.0d0))) - (0.5d0 * (1.0d0 / b)))
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 2.5) {
tmp = (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
} else {
tmp = c * ((-0.375 * ((a * c) / Math.pow(b, 3.0))) - (0.5 * (1.0 / b)));
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 2.5: tmp = (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a) else: tmp = c * ((-0.375 * ((a * c) / math.pow(b, 3.0))) - (0.5 * (1.0 / b))) return tmp
function code(a, b, c) tmp = 0.0 if (b <= 2.5) tmp = Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a)); else tmp = Float64(c * Float64(Float64(-0.375 * Float64(Float64(a * c) / (b ^ 3.0))) - Float64(0.5 * Float64(1.0 / b)))); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 2.5) tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a); else tmp = c * ((-0.375 * ((a * c) / (b ^ 3.0))) - (0.5 * (1.0 / b))); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 2.5], 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], N[(c * N[(N[(-0.375 * N[(N[(a * c), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 * N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 2.5:\\
\;\;\;\;\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}\\
\mathbf{else}:\\
\;\;\;\;c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right)\\
\end{array}
\end{array}
if b < 2.5Initial program 82.7%
if 2.5 < b Initial program 49.3%
Taylor expanded in c around 0 88.3%
(FPCore (a b c) :precision binary64 (* c (- (* -0.375 (/ (* a c) (pow b 3.0))) (* 0.5 (/ 1.0 b)))))
double code(double a, double b, double c) {
return c * ((-0.375 * ((a * c) / pow(b, 3.0))) - (0.5 * (1.0 / 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 * (((-0.375d0) * ((a * c) / (b ** 3.0d0))) - (0.5d0 * (1.0d0 / 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 * (1.0 / b)));
}
def code(a, b, c): return c * ((-0.375 * ((a * c) / math.pow(b, 3.0))) - (0.5 * (1.0 / b)))
function code(a, b, c) return Float64(c * Float64(Float64(-0.375 * Float64(Float64(a * c) / (b ^ 3.0))) - Float64(0.5 * Float64(1.0 / b)))) end
function tmp = code(a, b, c) tmp = c * ((-0.375 * ((a * c) / (b ^ 3.0))) - (0.5 * (1.0 / b))); end
code[a_, b_, c_] := N[(c * N[(N[(-0.375 * N[(N[(a * c), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 * N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \left(-0.375 \cdot \frac{a \cdot c}{{b}^{3}} - 0.5 \cdot \frac{1}{b}\right)
\end{array}
Initial program 55.9%
Taylor expanded in c around 0 82.5%
(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 55.9%
Taylor expanded in b around inf 64.2%
herbie shell --seed 2024076 -o generate:simplify
(FPCore (a b c)
:name "Cubic critical, narrow range"
:precision binary64
:pre (and (and (and (< 1.0536712127723509e-8 a) (< a 94906265.62425156)) (and (< 1.0536712127723509e-8 b) (< b 94906265.62425156))) (and (< 1.0536712127723509e-8 c) (< c 94906265.62425156)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))