
(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 8 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 (/ (/ (* a (* c -3.0)) (* a -3.0)) (- (- b) (sqrt (fma (* -3.0 c) a (* b b))))))
double code(double a, double b, double c) {
return ((a * (c * -3.0)) / (a * -3.0)) / (-b - sqrt(fma((-3.0 * c), a, (b * b))));
}
function code(a, b, c) return Float64(Float64(Float64(a * Float64(c * -3.0)) / Float64(a * -3.0)) / Float64(Float64(-b) - sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))))) end
code[a_, b_, c_] := N[(N[(N[(a * N[(c * -3.0), $MachinePrecision]), $MachinePrecision] / N[(a * -3.0), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{a \cdot \left(c \cdot -3\right)}{a \cdot -3}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)}}
\end{array}
Initial program 30.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites30.5%
Applied rewrites31.4%
lift--.f64N/A
lift-fma.f64N/A
+-commutativeN/A
associate--r+N/A
lower--.f64N/A
lower--.f64N/A
lower-*.f6499.3
Applied rewrites99.3%
lift-*.f64N/A
lift-/.f64N/A
metadata-evalN/A
associate-/r*N/A
lift-*.f64N/A
un-div-invN/A
frac-2negN/A
Applied rewrites99.3%
(FPCore (a b c) :precision binary64 (/ (* (* (* 3.0 c) a) (/ 0.3333333333333333 a)) (- (- b) (sqrt (fma (* -3.0 c) a (* b b))))))
double code(double a, double b, double c) {
return (((3.0 * c) * a) * (0.3333333333333333 / a)) / (-b - sqrt(fma((-3.0 * c), a, (b * b))));
}
function code(a, b, c) return Float64(Float64(Float64(Float64(3.0 * c) * a) * Float64(0.3333333333333333 / a)) / Float64(Float64(-b) - sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))))) end
code[a_, b_, c_] := N[(N[(N[(N[(3.0 * c), $MachinePrecision] * a), $MachinePrecision] * N[(0.3333333333333333 / a), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(\left(3 \cdot c\right) \cdot a\right) \cdot \frac{0.3333333333333333}{a}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)}}
\end{array}
Initial program 30.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites30.5%
Applied rewrites31.4%
lift--.f64N/A
lift-fma.f64N/A
+-commutativeN/A
associate--r+N/A
lower--.f64N/A
lower--.f64N/A
lower-*.f6499.3
Applied rewrites99.3%
lift--.f64N/A
lift-*.f64N/A
cancel-sign-sub-invN/A
lift--.f64N/A
+-inversesN/A
+-lft-identityN/A
lower-*.f64N/A
lift-*.f64N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f6499.3
Applied rewrites99.3%
(FPCore (a b c) :precision binary64 (/ (* (* (* 3.0 a) c) (/ 0.3333333333333333 a)) (- (- b) (sqrt (fma (* -3.0 c) a (* b b))))))
double code(double a, double b, double c) {
return (((3.0 * a) * c) * (0.3333333333333333 / a)) / (-b - sqrt(fma((-3.0 * c), a, (b * b))));
}
function code(a, b, c) return Float64(Float64(Float64(Float64(3.0 * a) * c) * Float64(0.3333333333333333 / a)) / Float64(Float64(-b) - sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))))) end
code[a_, b_, c_] := N[(N[(N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision] * N[(0.3333333333333333 / a), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(\left(3 \cdot a\right) \cdot c\right) \cdot \frac{0.3333333333333333}{a}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)}}
\end{array}
Initial program 30.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites30.5%
Applied rewrites31.4%
Taylor expanded in a around 0
associate-*r*N/A
lower-*.f64N/A
lower-*.f6499.2
Applied rewrites99.2%
(FPCore (a b c) :precision binary64 (/ (* (* a c) 3.0) (* (* 3.0 a) (- (- b) (sqrt (fma a (* c -3.0) (* b b)))))))
double code(double a, double b, double c) {
return ((a * c) * 3.0) / ((3.0 * a) * (-b - sqrt(fma(a, (c * -3.0), (b * b)))));
}
function code(a, b, c) return Float64(Float64(Float64(a * c) * 3.0) / Float64(Float64(3.0 * a) * Float64(Float64(-b) - sqrt(fma(a, Float64(c * -3.0), Float64(b * b)))))) end
code[a_, b_, c_] := N[(N[(N[(a * c), $MachinePrecision] * 3.0), $MachinePrecision] / N[(N[(3.0 * a), $MachinePrecision] * N[((-b) - N[Sqrt[N[(a * N[(c * -3.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(a \cdot c\right) \cdot 3}{\left(3 \cdot a\right) \cdot \left(\left(-b\right) - \sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)}\right)}
\end{array}
Initial program 30.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites30.5%
Applied rewrites31.4%
lift--.f64N/A
lift-fma.f64N/A
+-commutativeN/A
associate--r+N/A
lower--.f64N/A
lower--.f64N/A
lower-*.f6499.3
Applied rewrites99.3%
Applied rewrites99.1%
(FPCore (a b c) :precision binary64 (/ (* (* (* a c) 3.0) 0.3333333333333333) (* (- (- b) (sqrt (fma a (* c -3.0) (* b b)))) a)))
double code(double a, double b, double c) {
return (((a * c) * 3.0) * 0.3333333333333333) / ((-b - sqrt(fma(a, (c * -3.0), (b * b)))) * a);
}
function code(a, b, c) return Float64(Float64(Float64(Float64(a * c) * 3.0) * 0.3333333333333333) / Float64(Float64(Float64(-b) - sqrt(fma(a, Float64(c * -3.0), Float64(b * b)))) * a)) end
code[a_, b_, c_] := N[(N[(N[(N[(a * c), $MachinePrecision] * 3.0), $MachinePrecision] * 0.3333333333333333), $MachinePrecision] / N[(N[((-b) - N[Sqrt[N[(a * N[(c * -3.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(\left(a \cdot c\right) \cdot 3\right) \cdot 0.3333333333333333}{\left(\left(-b\right) - \sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)}\right) \cdot a}
\end{array}
Initial program 30.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites30.5%
Applied rewrites31.4%
Taylor expanded in a around 0
associate-*r*N/A
lower-*.f64N/A
lower-*.f6499.2
Applied rewrites99.2%
lift-/.f64N/A
lift-*.f64N/A
lift-/.f64N/A
associate-*r/N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites99.0%
(FPCore (a b c) :precision binary64 (/ (* a (* c -3.0)) (* (* 3.0 a) (+ b (sqrt (fma a (* c -3.0) (* b b)))))))
double code(double a, double b, double c) {
return (a * (c * -3.0)) / ((3.0 * a) * (b + sqrt(fma(a, (c * -3.0), (b * b)))));
}
function code(a, b, c) return Float64(Float64(a * Float64(c * -3.0)) / Float64(Float64(3.0 * a) * Float64(b + sqrt(fma(a, Float64(c * -3.0), Float64(b * b)))))) end
code[a_, b_, c_] := N[(N[(a * N[(c * -3.0), $MachinePrecision]), $MachinePrecision] / N[(N[(3.0 * a), $MachinePrecision] * N[(b + N[Sqrt[N[(a * N[(c * -3.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{a \cdot \left(c \cdot -3\right)}{\left(3 \cdot a\right) \cdot \left(b + \sqrt{\mathsf{fma}\left(a, c \cdot -3, b \cdot b\right)}\right)}
\end{array}
Initial program 30.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites30.5%
Applied rewrites31.4%
lift--.f64N/A
lift-fma.f64N/A
+-commutativeN/A
associate--r+N/A
lower--.f64N/A
lower--.f64N/A
lower-*.f6499.3
Applied rewrites99.3%
Applied rewrites99.2%
Final simplification99.2%
(FPCore (a b c) :precision binary64 (/ 0.3333333333333333 (fma -0.6666666666666666 (/ b c) (* 0.5 (/ a b)))))
double code(double a, double b, double c) {
return 0.3333333333333333 / fma(-0.6666666666666666, (b / c), (0.5 * (a / b)));
}
function code(a, b, c) return Float64(0.3333333333333333 / fma(-0.6666666666666666, Float64(b / c), Float64(0.5 * Float64(a / b)))) end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(-0.6666666666666666 * N[(b / c), $MachinePrecision] + N[(0.5 * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.3333333333333333}{\mathsf{fma}\left(-0.6666666666666666, \frac{b}{c}, 0.5 \cdot \frac{a}{b}\right)}
\end{array}
Initial program 30.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6430.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6430.5
Applied rewrites30.5%
Taylor expanded in a around 0
lower-fma.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-/.f6490.4
Applied rewrites90.4%
(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 30.5%
Taylor expanded in a around 0
lower-*.f64N/A
lower-/.f6481.5
Applied rewrites81.5%
herbie shell --seed 2024314
(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)))