
(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
(let* ((t_0 (* b (* b b))) (t_1 (* b t_0)))
(fma
a
(fma
a
(fma
(/ (/ (* (* c (* c (* c c))) (* a 6.328125)) (* (* b b) t_1)) b)
-0.16666666666666666
(/ (* (* c c) (* c -0.5625)) (* b t_1)))
(/ (* (* c c) -0.375) t_0))
(/ (* c -0.5) b))))
double code(double a, double b, double c) {
double t_0 = b * (b * b);
double t_1 = b * t_0;
return fma(a, fma(a, fma(((((c * (c * (c * c))) * (a * 6.328125)) / ((b * b) * t_1)) / b), -0.16666666666666666, (((c * c) * (c * -0.5625)) / (b * t_1))), (((c * c) * -0.375) / t_0)), ((c * -0.5) / b));
}
function code(a, b, c) t_0 = Float64(b * Float64(b * b)) t_1 = Float64(b * t_0) return fma(a, fma(a, fma(Float64(Float64(Float64(Float64(c * Float64(c * Float64(c * c))) * Float64(a * 6.328125)) / Float64(Float64(b * b) * t_1)) / b), -0.16666666666666666, Float64(Float64(Float64(c * c) * Float64(c * -0.5625)) / Float64(b * t_1))), Float64(Float64(Float64(c * c) * -0.375) / t_0)), Float64(Float64(c * -0.5) / b)) end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(b * t$95$0), $MachinePrecision]}, N[(a * N[(a * N[(N[(N[(N[(N[(c * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(a * 6.328125), $MachinePrecision]), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision] * -0.16666666666666666 + N[(N[(N[(c * c), $MachinePrecision] * N[(c * -0.5625), $MachinePrecision]), $MachinePrecision] / N[(b * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] + N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot b\right)\\
t_1 := b \cdot t\_0\\
\mathsf{fma}\left(a, \mathsf{fma}\left(a, \mathsf{fma}\left(\frac{\frac{\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \left(a \cdot 6.328125\right)}{\left(b \cdot b\right) \cdot t\_1}}{b}, -0.16666666666666666, \frac{\left(c \cdot c\right) \cdot \left(c \cdot -0.5625\right)}{b \cdot t\_1}\right), \frac{\left(c \cdot c\right) \cdot -0.375}{t\_0}\right), \frac{c \cdot -0.5}{b}\right)
\end{array}
\end{array}
Initial program 20.0%
Taylor expanded in a around 0
Simplified97.9%
lift-pow.f64N/A
lift-pow.f64N/A
lift-*.f64N/A
associate-*l/N/A
lower-/.f64N/A
lower-*.f6497.9
lift-pow.f64N/A
metadata-evalN/A
pow-prod-upN/A
pow2N/A
pow2N/A
lift-*.f64N/A
associate-*l*N/A
lift-*.f64N/A
lower-*.f6497.9
lift-pow.f64N/A
metadata-evalN/A
pow-powN/A
pow2N/A
lift-*.f64N/A
cube-multN/A
lift-*.f64N/A
associate-*r*N/A
lift-*.f64N/A
lift-*.f64N/A
lower-*.f6497.9
Applied egg-rr97.9%
lift-*.f64N/A
lift-*.f64N/A
lift-*.f64N/A
metadata-evalN/A
pow-prod-upN/A
pow2N/A
cube-unmultN/A
lift-*.f64N/A
lift-*.f64N/A
associate-*r*N/A
lift-*.f64N/A
lower-/.f64N/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-*l*N/A
lower-*.f64N/A
lower-*.f64N/A
lower-*.f6497.9
Applied egg-rr97.9%
Final simplification97.9%
(FPCore (a b c)
:precision binary64
(/
1.0
(/
(fma
c
(fma (* c 3.0) (* (/ (* a a) (* b (* b b))) 0.375) (/ (* a 1.5) b))
(* b -2.0))
c)))
double code(double a, double b, double c) {
return 1.0 / (fma(c, fma((c * 3.0), (((a * a) / (b * (b * b))) * 0.375), ((a * 1.5) / b)), (b * -2.0)) / c);
}
function code(a, b, c) return Float64(1.0 / Float64(fma(c, fma(Float64(c * 3.0), Float64(Float64(Float64(a * a) / Float64(b * Float64(b * b))) * 0.375), Float64(Float64(a * 1.5) / b)), Float64(b * -2.0)) / c)) end
code[a_, b_, c_] := N[(1.0 / N[(N[(c * N[(N[(c * 3.0), $MachinePrecision] * N[(N[(N[(a * a), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.375), $MachinePrecision] + N[(N[(a * 1.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision] + N[(b * -2.0), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{\mathsf{fma}\left(c, \mathsf{fma}\left(c \cdot 3, \frac{a \cdot a}{b \cdot \left(b \cdot b\right)} \cdot 0.375, \frac{a \cdot 1.5}{b}\right), b \cdot -2\right)}{c}}
\end{array}
Initial program 20.0%
Applied egg-rr20.0%
lift-*.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
lift-sqrt.f64N/A
lift--.f64N/A
lift-/.f64N/A
lift-*.f64N/A
clear-numN/A
lower-/.f64N/A
lift-*.f64N/A
lift-/.f64N/A
un-div-invN/A
associate-/r/N/A
Applied egg-rr20.0%
Taylor expanded in c around 0
lower-/.f64N/A
Simplified96.8%
Final simplification96.8%
(FPCore (a b c) :precision binary64 (/ 1.0 (fma a (fma (* a 3.0) (* 0.375 (/ c (* b (* b b)))) (/ 1.5 b)) (/ (* b -2.0) c))))
double code(double a, double b, double c) {
return 1.0 / fma(a, fma((a * 3.0), (0.375 * (c / (b * (b * b)))), (1.5 / b)), ((b * -2.0) / c));
}
function code(a, b, c) return Float64(1.0 / fma(a, fma(Float64(a * 3.0), Float64(0.375 * Float64(c / Float64(b * Float64(b * b)))), Float64(1.5 / b)), Float64(Float64(b * -2.0) / c))) end
code[a_, b_, c_] := N[(1.0 / N[(a * N[(N[(a * 3.0), $MachinePrecision] * N[(0.375 * N[(c / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.5 / b), $MachinePrecision]), $MachinePrecision] + N[(N[(b * -2.0), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(a, \mathsf{fma}\left(a \cdot 3, 0.375 \cdot \frac{c}{b \cdot \left(b \cdot b\right)}, \frac{1.5}{b}\right), \frac{b \cdot -2}{c}\right)}
\end{array}
Initial program 20.0%
Applied egg-rr20.0%
lift-*.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
lift-sqrt.f64N/A
lift--.f64N/A
lift-/.f64N/A
lift-*.f64N/A
clear-numN/A
lower-/.f64N/A
lift-*.f64N/A
lift-/.f64N/A
un-div-invN/A
associate-/r/N/A
Applied egg-rr20.0%
Taylor expanded in a around 0
+-commutativeN/A
lower-fma.f64N/A
Simplified96.8%
Final simplification96.8%
(FPCore (a b c) :precision binary64 (fma a (/ (* (* c c) -0.375) (* b (* b b))) (/ (* c -0.5) b)))
double code(double a, double b, double c) {
return fma(a, (((c * c) * -0.375) / (b * (b * b))), ((c * -0.5) / b));
}
function code(a, b, c) return fma(a, Float64(Float64(Float64(c * c) * -0.375) / Float64(b * Float64(b * b))), Float64(Float64(c * -0.5) / b)) end
code[a_, b_, c_] := N[(a * N[(N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(a, \frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot \left(b \cdot b\right)}, \frac{c \cdot -0.5}{b}\right)
\end{array}
Initial program 20.0%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
associate-/l*N/A
associate-*r*N/A
*-commutativeN/A
lower-fma.f64N/A
associate-*r/N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
cube-multN/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
associate-*r/N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f6494.8
Simplified94.8%
(FPCore (a b c) :precision binary64 (/ (fma a (* -0.375 (* c (/ c (* b b)))) (* c -0.5)) b))
double code(double a, double b, double c) {
return fma(a, (-0.375 * (c * (c / (b * b)))), (c * -0.5)) / b;
}
function code(a, b, c) return Float64(fma(a, Float64(-0.375 * Float64(c * Float64(c / Float64(b * b)))), Float64(c * -0.5)) / b) end
code[a_, b_, c_] := N[(N[(a * N[(-0.375 * N[(c * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c * -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(a, -0.375 \cdot \left(c \cdot \frac{c}{b \cdot b}\right), c \cdot -0.5\right)}{b}
\end{array}
Initial program 20.0%
Taylor expanded in b around inf
lower-/.f64N/A
Simplified94.8%
(FPCore (a b c) :precision binary64 (/ 1.0 (fma -2.0 (/ b c) (/ (* a 1.5) b))))
double code(double a, double b, double c) {
return 1.0 / fma(-2.0, (b / c), ((a * 1.5) / b));
}
function code(a, b, c) return Float64(1.0 / fma(-2.0, Float64(b / c), Float64(Float64(a * 1.5) / b))) end
code[a_, b_, c_] := N[(1.0 / N[(-2.0 * N[(b / c), $MachinePrecision] + N[(N[(a * 1.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(-2, \frac{b}{c}, \frac{a \cdot 1.5}{b}\right)}
\end{array}
Initial program 20.0%
Applied egg-rr20.0%
lift-*.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
lift-sqrt.f64N/A
lift--.f64N/A
lift-/.f64N/A
lift-*.f64N/A
clear-numN/A
lower-/.f64N/A
lift-*.f64N/A
lift-/.f64N/A
un-div-invN/A
associate-/r/N/A
Applied egg-rr20.0%
Taylor expanded in a around 0
lower-fma.f64N/A
lower-/.f64N/A
associate-*r/N/A
lower-/.f64N/A
lower-*.f6494.7
Simplified94.7%
Final simplification94.7%
(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 20.0%
Taylor expanded in b around inf
associate-*r/N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f6488.7
Simplified88.7%
(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(c * Float64(-0.5 / b)) end
function tmp = code(a, b, c) tmp = c * (-0.5 / b); end
code[a_, b_, c_] := N[(c * N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \frac{-0.5}{b}
\end{array}
Initial program 20.0%
Taylor expanded in b around inf
associate-*r/N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f6488.7
Simplified88.7%
*-commutativeN/A
associate-*l/N/A
lift-/.f64N/A
lower-*.f6488.3
Applied egg-rr88.3%
Final simplification88.3%
herbie shell --seed 2024215
(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)))