
(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 9 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))))
(/
(fma
c
-0.5
(+
(fma
a
(/ (* (* c c) -0.375) (* b b))
(/
(*
-0.16666666666666666
(* (* a (* a (* a a))) (* (* c c) (* (* c c) 6.328125))))
(* t_0 (* a t_0))))
(* (* a a) (/ (* c (* (* c c) -0.5625)) (* b t_0)))))
b)))
double code(double a, double b, double c) {
double t_0 = b * (b * b);
return fma(c, -0.5, (fma(a, (((c * c) * -0.375) / (b * b)), ((-0.16666666666666666 * ((a * (a * (a * a))) * ((c * c) * ((c * c) * 6.328125)))) / (t_0 * (a * t_0)))) + ((a * a) * ((c * ((c * c) * -0.5625)) / (b * t_0))))) / b;
}
function code(a, b, c) t_0 = Float64(b * Float64(b * b)) return Float64(fma(c, -0.5, Float64(fma(a, Float64(Float64(Float64(c * c) * -0.375) / Float64(b * b)), Float64(Float64(-0.16666666666666666 * Float64(Float64(a * Float64(a * Float64(a * a))) * Float64(Float64(c * c) * Float64(Float64(c * c) * 6.328125)))) / Float64(t_0 * Float64(a * t_0)))) + Float64(Float64(a * a) * Float64(Float64(c * Float64(Float64(c * c) * -0.5625)) / Float64(b * t_0))))) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(c * -0.5 + N[(N[(a * N[(N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(N[(-0.16666666666666666 * N[(N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] * 6.328125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(t$95$0 * N[(a * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a * a), $MachinePrecision] * N[(N[(c * N[(N[(c * c), $MachinePrecision] * -0.5625), $MachinePrecision]), $MachinePrecision] / N[(b * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot b\right)\\
\frac{\mathsf{fma}\left(c, -0.5, \mathsf{fma}\left(a, \frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot b}, \frac{-0.16666666666666666 \cdot \left(\left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot c\right) \cdot \left(\left(c \cdot c\right) \cdot 6.328125\right)\right)\right)}{t\_0 \cdot \left(a \cdot t\_0\right)}\right) + \left(a \cdot a\right) \cdot \frac{c \cdot \left(\left(c \cdot c\right) \cdot -0.5625\right)}{b \cdot t\_0}\right)}{b}
\end{array}
\end{array}
Initial program 34.7%
Taylor expanded in b around inf
Applied rewrites95.8%
Applied rewrites95.9%
Final simplification95.9%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (* c (* c c))) (t_1 (* (* b b) (* b b))))
(/
(fma
c
-0.5
(fma
(/ (* (* a a) (* a (* 6.328125 (* c t_0)))) (* (* b b) t_1))
-0.16666666666666666
(* a (fma (* -0.5625 t_0) (/ a t_1) (/ (* (* c c) -0.375) (* b b))))))
b)))
double code(double a, double b, double c) {
double t_0 = c * (c * c);
double t_1 = (b * b) * (b * b);
return fma(c, -0.5, fma((((a * a) * (a * (6.328125 * (c * t_0)))) / ((b * b) * t_1)), -0.16666666666666666, (a * fma((-0.5625 * t_0), (a / t_1), (((c * c) * -0.375) / (b * b)))))) / b;
}
function code(a, b, c) t_0 = Float64(c * Float64(c * c)) t_1 = Float64(Float64(b * b) * Float64(b * b)) return Float64(fma(c, -0.5, fma(Float64(Float64(Float64(a * a) * Float64(a * Float64(6.328125 * Float64(c * t_0)))) / Float64(Float64(b * b) * t_1)), -0.16666666666666666, Float64(a * fma(Float64(-0.5625 * t_0), Float64(a / t_1), Float64(Float64(Float64(c * c) * -0.375) / Float64(b * b)))))) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(b * b), $MachinePrecision] * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(c * -0.5 + N[(N[(N[(N[(a * a), $MachinePrecision] * N[(a * N[(6.328125 * N[(c * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666 + N[(a * N[(N[(-0.5625 * t$95$0), $MachinePrecision] * N[(a / t$95$1), $MachinePrecision] + N[(N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := c \cdot \left(c \cdot c\right)\\
t_1 := \left(b \cdot b\right) \cdot \left(b \cdot b\right)\\
\frac{\mathsf{fma}\left(c, -0.5, \mathsf{fma}\left(\frac{\left(a \cdot a\right) \cdot \left(a \cdot \left(6.328125 \cdot \left(c \cdot t\_0\right)\right)\right)}{\left(b \cdot b\right) \cdot t\_1}, -0.16666666666666666, a \cdot \mathsf{fma}\left(-0.5625 \cdot t\_0, \frac{a}{t\_1}, \frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot b}\right)\right)\right)}{b}
\end{array}
\end{array}
Initial program 34.7%
Taylor expanded in b around inf
Applied rewrites95.8%
Applied rewrites95.9%
Applied rewrites95.9%
Applied rewrites95.9%
Final simplification95.9%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (* c (* c c))) (t_1 (* (* b b) (* b b))))
(/
(fma
a
(fma (* -0.5625 t_0) (/ a t_1) (/ (* (* c c) -0.375) (* b b)))
(fma
(/ (* (* a a) (* a (* 6.328125 (* c t_0)))) (* (* b b) t_1))
-0.16666666666666666
(* c -0.5)))
b)))
double code(double a, double b, double c) {
double t_0 = c * (c * c);
double t_1 = (b * b) * (b * b);
return fma(a, fma((-0.5625 * t_0), (a / t_1), (((c * c) * -0.375) / (b * b))), fma((((a * a) * (a * (6.328125 * (c * t_0)))) / ((b * b) * t_1)), -0.16666666666666666, (c * -0.5))) / b;
}
function code(a, b, c) t_0 = Float64(c * Float64(c * c)) t_1 = Float64(Float64(b * b) * Float64(b * b)) return Float64(fma(a, fma(Float64(-0.5625 * t_0), Float64(a / t_1), Float64(Float64(Float64(c * c) * -0.375) / Float64(b * b))), fma(Float64(Float64(Float64(a * a) * Float64(a * Float64(6.328125 * Float64(c * t_0)))) / Float64(Float64(b * b) * t_1)), -0.16666666666666666, Float64(c * -0.5))) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(b * b), $MachinePrecision] * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(a * N[(N[(-0.5625 * t$95$0), $MachinePrecision] * N[(a / t$95$1), $MachinePrecision] + N[(N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(a * a), $MachinePrecision] * N[(a * N[(6.328125 * N[(c * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision] * -0.16666666666666666 + N[(c * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := c \cdot \left(c \cdot c\right)\\
t_1 := \left(b \cdot b\right) \cdot \left(b \cdot b\right)\\
\frac{\mathsf{fma}\left(a, \mathsf{fma}\left(-0.5625 \cdot t\_0, \frac{a}{t\_1}, \frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot b}\right), \mathsf{fma}\left(\frac{\left(a \cdot a\right) \cdot \left(a \cdot \left(6.328125 \cdot \left(c \cdot t\_0\right)\right)\right)}{\left(b \cdot b\right) \cdot t\_1}, -0.16666666666666666, c \cdot -0.5\right)\right)}{b}
\end{array}
\end{array}
Initial program 34.7%
Taylor expanded in b around inf
Applied rewrites95.8%
Applied rewrites95.9%
Applied rewrites95.9%
Applied rewrites95.9%
Final simplification95.9%
(FPCore (a b c)
:precision binary64
(/
(fma
c
-0.5
(/
(fma
-0.5625
(/ (* (* a a) (* c (* c c))) (* b b))
(* -0.375 (* a (* c c))))
(* b b)))
b))
double code(double a, double b, double c) {
return fma(c, -0.5, (fma(-0.5625, (((a * a) * (c * (c * c))) / (b * b)), (-0.375 * (a * (c * c)))) / (b * b))) / b;
}
function code(a, b, c) return Float64(fma(c, -0.5, Float64(fma(-0.5625, Float64(Float64(Float64(a * a) * Float64(c * Float64(c * c))) / Float64(b * b)), Float64(-0.375 * Float64(a * Float64(c * c)))) / Float64(b * b))) / b) end
code[a_, b_, c_] := N[(N[(c * -0.5 + N[(N[(-0.5625 * N[(N[(N[(a * a), $MachinePrecision] * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(-0.375 * N[(a * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(c, -0.5, \frac{\mathsf{fma}\left(-0.5625, \frac{\left(a \cdot a\right) \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot b}, -0.375 \cdot \left(a \cdot \left(c \cdot c\right)\right)\right)}{b \cdot b}\right)}{b}
\end{array}
Initial program 34.7%
Taylor expanded in b around inf
Applied rewrites95.8%
Applied rewrites95.9%
Taylor expanded in b around inf
Applied rewrites94.2%
Final simplification94.2%
(FPCore (a b c) :precision binary64 (* c (fma c (/ (fma -0.5625 (/ (* c (* a a)) (* b b)) (* a -0.375)) (* b (* b b))) (/ -0.5 b))))
double code(double a, double b, double c) {
return c * fma(c, (fma(-0.5625, ((c * (a * a)) / (b * b)), (a * -0.375)) / (b * (b * b))), (-0.5 / b));
}
function code(a, b, c) return Float64(c * fma(c, Float64(fma(-0.5625, Float64(Float64(c * Float64(a * a)) / Float64(b * b)), Float64(a * -0.375)) / Float64(b * Float64(b * b))), Float64(-0.5 / b))) end
code[a_, b_, c_] := N[(c * N[(c * N[(N[(-0.5625 * N[(N[(c * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(a * -0.375), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \mathsf{fma}\left(c, \frac{\mathsf{fma}\left(-0.5625, \frac{c \cdot \left(a \cdot a\right)}{b \cdot b}, a \cdot -0.375\right)}{b \cdot \left(b \cdot b\right)}, \frac{-0.5}{b}\right)
\end{array}
Initial program 34.7%
Taylor expanded in c around 0
lower-*.f64N/A
sub-negN/A
associate-*r/N/A
associate-*r*N/A
associate-*l/N/A
associate-*r/N/A
+-commutativeN/A
lower-fma.f64N/A
Applied rewrites93.9%
Taylor expanded in b around inf
Applied rewrites93.9%
Final simplification93.9%
(FPCore (a b c) :precision binary64 (/ (fma a (/ (* (* c c) -0.375) (* b b)) (* c -0.5)) b))
double code(double a, double b, double c) {
return fma(a, (((c * c) * -0.375) / (b * b)), (c * -0.5)) / b;
}
function code(a, b, c) return Float64(fma(a, Float64(Float64(Float64(c * c) * -0.375) / Float64(b * b)), Float64(c * -0.5)) / b) end
code[a_, b_, c_] := N[(N[(a * N[(N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(c * -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(a, \frac{\left(c \cdot c\right) \cdot -0.375}{b \cdot b}, c \cdot -0.5\right)}{b}
\end{array}
Initial program 34.7%
Taylor expanded in b around inf
lower-/.f64N/A
Applied rewrites90.5%
(FPCore (a b c) :precision binary64 (/ (* c (fma (/ a (* b b)) (* c -0.375) -0.5)) b))
double code(double a, double b, double c) {
return (c * fma((a / (b * b)), (c * -0.375), -0.5)) / b;
}
function code(a, b, c) return Float64(Float64(c * fma(Float64(a / Float64(b * b)), Float64(c * -0.375), -0.5)) / b) end
code[a_, b_, c_] := N[(N[(c * N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(c * -0.375), $MachinePrecision] + -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \mathsf{fma}\left(\frac{a}{b \cdot b}, c \cdot -0.375, -0.5\right)}{b}
\end{array}
Initial program 34.7%
Taylor expanded in b around inf
Applied rewrites95.8%
Taylor expanded in b around inf
lower-/.f64N/A
Applied rewrites90.5%
Final simplification90.5%
(FPCore (a b c) :precision binary64 (* c (/ (fma (/ a (* b b)) (* c -0.375) -0.5) b)))
double code(double a, double b, double c) {
return c * (fma((a / (b * b)), (c * -0.375), -0.5) / b);
}
function code(a, b, c) return Float64(c * Float64(fma(Float64(a / Float64(b * b)), Float64(c * -0.375), -0.5) / b)) end
code[a_, b_, c_] := N[(c * N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(c * -0.375), $MachinePrecision] + -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \frac{\mathsf{fma}\left(\frac{a}{b \cdot b}, c \cdot -0.375, -0.5\right)}{b}
\end{array}
Initial program 34.7%
Taylor expanded in b around inf
Applied rewrites95.8%
Taylor expanded in c around 0
lower-*.f64N/A
associate-*r/N/A
unpow3N/A
unpow2N/A
associate-/r*N/A
associate-*r/N/A
associate-*r/N/A
metadata-evalN/A
div-subN/A
Applied rewrites90.3%
Final simplification90.3%
(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 34.7%
Taylor expanded in b around inf
lower-*.f64N/A
lower-/.f6479.5
Applied rewrites79.5%
herbie shell --seed 2024221
(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)))