
(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
(/
0.3333333333333333
(/
a
(/
(/ (* (- a) (* c (sqrt 27.0))) (sqrt 3.0))
(+ (sqrt (fma (* -3.0 c) a (* b b))) b)))))
double code(double a, double b, double c) {
return 0.3333333333333333 / (a / (((-a * (c * sqrt(27.0))) / sqrt(3.0)) / (sqrt(fma((-3.0 * c), a, (b * b))) + b)));
}
function code(a, b, c) return Float64(0.3333333333333333 / Float64(a / Float64(Float64(Float64(Float64(-a) * Float64(c * sqrt(27.0))) / sqrt(3.0)) / Float64(sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))) + b)))) end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(a / N[(N[(N[((-a) * N[(c * N[Sqrt[27.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Sqrt[3.0], $MachinePrecision]), $MachinePrecision] / N[(N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.3333333333333333}{\frac{a}{\frac{\frac{\left(-a\right) \cdot \left(c \cdot \sqrt{27}\right)}{\sqrt{3}}}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b}}}
\end{array}
Initial program 29.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6429.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6429.5
Applied rewrites29.5%
Applied rewrites29.8%
Applied rewrites29.6%
Taylor expanded in a around -inf
mul-1-negN/A
lower-neg.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-*.f64N/A
lower-sqrt.f64N/A
lower-sqrt.f6499.1
Applied rewrites99.1%
Final simplification99.1%
(FPCore (a b c)
:precision binary64
(pow
(/
a
(*
(/ (fma (* -3.0 a) c 0.0) (+ (sqrt (fma (* -3.0 c) a (* b b))) b))
0.3333333333333333))
-1.0))
double code(double a, double b, double c) {
return pow((a / ((fma((-3.0 * a), c, 0.0) / (sqrt(fma((-3.0 * c), a, (b * b))) + b)) * 0.3333333333333333)), -1.0);
}
function code(a, b, c) return Float64(a / Float64(Float64(fma(Float64(-3.0 * a), c, 0.0) / Float64(sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))) + b)) * 0.3333333333333333)) ^ -1.0 end
code[a_, b_, c_] := N[Power[N[(a / N[(N[(N[(N[(-3.0 * a), $MachinePrecision] * c + 0.0), $MachinePrecision] / N[(N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{a}{\frac{\mathsf{fma}\left(-3 \cdot a, c, 0\right)}{\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b} \cdot 0.3333333333333333}\right)}^{-1}
\end{array}
Initial program 29.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6429.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6429.5
Applied rewrites29.5%
Applied rewrites29.8%
Applied rewrites29.5%
lift--.f64N/A
flip--N/A
lift-+.f64N/A
lower-/.f64N/A
Applied rewrites99.0%
Final simplification99.0%
(FPCore (a b c) :precision binary64 (pow (/ (fma -2.0 b (* 1.5 (/ (* a c) b))) c) -1.0))
double code(double a, double b, double c) {
return pow((fma(-2.0, b, (1.5 * ((a * c) / b))) / c), -1.0);
}
function code(a, b, c) return Float64(fma(-2.0, b, Float64(1.5 * Float64(Float64(a * c) / b))) / c) ^ -1.0 end
code[a_, b_, c_] := N[Power[N[(N[(-2.0 * b + N[(1.5 * N[(N[(a * c), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{\mathsf{fma}\left(-2, b, 1.5 \cdot \frac{a \cdot c}{b}\right)}{c}\right)}^{-1}
\end{array}
Initial program 29.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6429.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6429.5
Applied rewrites29.5%
Applied rewrites29.8%
Applied rewrites29.5%
Taylor expanded in c around 0
lower-/.f64N/A
lower-fma.f64N/A
lower-*.f64N/A
lower-/.f64N/A
lower-*.f6490.8
Applied rewrites90.8%
Final simplification90.8%
(FPCore (a b c) :precision binary64 (pow (fma -2.0 (/ b c) (* 1.5 (/ a b))) -1.0))
double code(double a, double b, double c) {
return pow(fma(-2.0, (b / c), (1.5 * (a / b))), -1.0);
}
function code(a, b, c) return fma(-2.0, Float64(b / c), Float64(1.5 * Float64(a / b))) ^ -1.0 end
code[a_, b_, c_] := N[Power[N[(-2.0 * N[(b / c), $MachinePrecision] + N[(1.5 * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\mathsf{fma}\left(-2, \frac{b}{c}, 1.5 \cdot \frac{a}{b}\right)\right)}^{-1}
\end{array}
Initial program 29.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6429.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6429.5
Applied rewrites29.5%
Applied rewrites29.8%
Applied rewrites29.5%
Taylor expanded in a around 0
lower-fma.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-/.f6490.8
Applied rewrites90.8%
Final simplification90.8%
(FPCore (a b c) :precision binary64 (/ 0.3333333333333333 (* (/ a (fma (* -3.0 a) c 0.0)) (+ (sqrt (fma (* -3.0 c) a (* b b))) b))))
double code(double a, double b, double c) {
return 0.3333333333333333 / ((a / fma((-3.0 * a), c, 0.0)) * (sqrt(fma((-3.0 * c), a, (b * b))) + b));
}
function code(a, b, c) return Float64(0.3333333333333333 / Float64(Float64(a / fma(Float64(-3.0 * a), c, 0.0)) * Float64(sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))) + b))) end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(N[(a / N[(N[(-3.0 * a), $MachinePrecision] * c + 0.0), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.3333333333333333}{\frac{a}{\mathsf{fma}\left(-3 \cdot a, c, 0\right)} \cdot \left(\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b\right)}
\end{array}
Initial program 29.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6429.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6429.5
Applied rewrites29.5%
Applied rewrites30.1%
Applied rewrites99.0%
(FPCore (a b c) :precision binary64 (/ (* c (fma -0.375 (/ (* a c) (* b b)) -0.5)) b))
double code(double a, double b, double c) {
return (c * fma(-0.375, ((a * c) / (b * b)), -0.5)) / b;
}
function code(a, b, c) return Float64(Float64(c * fma(-0.375, Float64(Float64(a * c) / Float64(b * b)), -0.5)) / b) end
code[a_, b_, c_] := N[(N[(c * N[(-0.375 * N[(N[(a * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{b}
\end{array}
Initial program 29.5%
Taylor expanded in b around inf
Applied rewrites95.8%
Applied rewrites95.8%
Taylor expanded in a around 0
Applied rewrites95.8%
Taylor expanded in c around 0
Applied rewrites90.6%
(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 29.5%
Taylor expanded in a around 0
lower-*.f64N/A
lower-/.f6482.3
Applied rewrites82.3%
herbie shell --seed 2024298
(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)))