
(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 b)))))
(/
(fma
-1.0546875
(* a (/ (* (* c c) (* (* a a) (* c c))) (* b (* b t_0))))
(fma
c
-0.5
(fma
-0.5625
(/ (* a (* a (* c (* c c)))) t_0)
(/ (* a (* (* c c) -0.375)) (* b b)))))
b)))
double code(double a, double b, double c) {
double t_0 = b * (b * (b * b));
return fma(-1.0546875, (a * (((c * c) * ((a * a) * (c * c))) / (b * (b * t_0)))), fma(c, -0.5, fma(-0.5625, ((a * (a * (c * (c * c)))) / t_0), ((a * ((c * c) * -0.375)) / (b * b))))) / b;
}
function code(a, b, c) t_0 = Float64(b * Float64(b * Float64(b * b))) return Float64(fma(-1.0546875, Float64(a * Float64(Float64(Float64(c * c) * Float64(Float64(a * a) * Float64(c * c))) / Float64(b * Float64(b * t_0)))), fma(c, -0.5, fma(-0.5625, Float64(Float64(a * Float64(a * Float64(c * Float64(c * c)))) / t_0), Float64(Float64(a * Float64(Float64(c * c) * -0.375)) / Float64(b * b))))) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(-1.0546875 * N[(a * N[(N[(N[(c * c), $MachinePrecision] * N[(N[(a * a), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c * -0.5 + N[(-0.5625 * N[(N[(a * N[(a * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] + N[(N[(a * N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot \left(b \cdot b\right)\right)\\
\frac{\mathsf{fma}\left(-1.0546875, a \cdot \frac{\left(c \cdot c\right) \cdot \left(\left(a \cdot a\right) \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot t\_0\right)}, \mathsf{fma}\left(c, -0.5, \mathsf{fma}\left(-0.5625, \frac{a \cdot \left(a \cdot \left(c \cdot \left(c \cdot c\right)\right)\right)}{t\_0}, \frac{a \cdot \left(\left(c \cdot c\right) \cdot -0.375\right)}{b \cdot b}\right)\right)\right)}{b}
\end{array}
\end{array}
Initial program 19.8%
Taylor expanded in c around 0
Simplified97.1%
Taylor expanded in b around inf
lower-/.f64N/A
Simplified97.4%
Applied egg-rr97.4%
Applied egg-rr97.4%
Final simplification97.4%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (* b (* b (* b b)))))
(/
(fma
-1.0546875
(* a (/ (* (* c c) (* (* a a) (* c c))) (* b (* b t_0))))
(fma
-0.5625
(/ (* (* a a) (* c (* c c))) t_0)
(fma -0.375 (* (* c c) (/ a (* b b))) (* c -0.5))))
b)))
double code(double a, double b, double c) {
double t_0 = b * (b * (b * b));
return fma(-1.0546875, (a * (((c * c) * ((a * a) * (c * c))) / (b * (b * t_0)))), fma(-0.5625, (((a * a) * (c * (c * c))) / t_0), fma(-0.375, ((c * c) * (a / (b * b))), (c * -0.5)))) / b;
}
function code(a, b, c) t_0 = Float64(b * Float64(b * Float64(b * b))) return Float64(fma(-1.0546875, Float64(a * Float64(Float64(Float64(c * c) * Float64(Float64(a * a) * Float64(c * c))) / Float64(b * Float64(b * t_0)))), fma(-0.5625, Float64(Float64(Float64(a * a) * Float64(c * Float64(c * c))) / t_0), fma(-0.375, Float64(Float64(c * c) * Float64(a / Float64(b * b))), Float64(c * -0.5)))) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(-1.0546875 * N[(a * N[(N[(N[(c * c), $MachinePrecision] * N[(N[(a * a), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5625 * N[(N[(N[(a * a), $MachinePrecision] * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] + N[(-0.375 * N[(N[(c * c), $MachinePrecision] * N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot \left(b \cdot b\right)\right)\\
\frac{\mathsf{fma}\left(-1.0546875, a \cdot \frac{\left(c \cdot c\right) \cdot \left(\left(a \cdot a\right) \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot t\_0\right)}, \mathsf{fma}\left(-0.5625, \frac{\left(a \cdot a\right) \cdot \left(c \cdot \left(c \cdot c\right)\right)}{t\_0}, \mathsf{fma}\left(-0.375, \left(c \cdot c\right) \cdot \frac{a}{b \cdot b}, c \cdot -0.5\right)\right)\right)}{b}
\end{array}
\end{array}
Initial program 19.8%
Taylor expanded in c around 0
Simplified97.1%
Taylor expanded in b around inf
lower-/.f64N/A
Simplified97.4%
Applied egg-rr97.4%
Final simplification97.4%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (* b (* b (* b b)))))
(/
(fma
-1.0546875
(* a (/ (* (* c c) (* (* a a) (* c c))) (* b (* b t_0))))
(fma
-0.5625
(/ (* (* a a) (* c (* c c))) t_0)
(* c (fma -0.375 (* a (/ c (* b b))) -0.5))))
b)))
double code(double a, double b, double c) {
double t_0 = b * (b * (b * b));
return fma(-1.0546875, (a * (((c * c) * ((a * a) * (c * c))) / (b * (b * t_0)))), fma(-0.5625, (((a * a) * (c * (c * c))) / t_0), (c * fma(-0.375, (a * (c / (b * b))), -0.5)))) / b;
}
function code(a, b, c) t_0 = Float64(b * Float64(b * Float64(b * b))) return Float64(fma(-1.0546875, Float64(a * Float64(Float64(Float64(c * c) * Float64(Float64(a * a) * Float64(c * c))) / Float64(b * Float64(b * t_0)))), fma(-0.5625, Float64(Float64(Float64(a * a) * Float64(c * Float64(c * c))) / t_0), Float64(c * fma(-0.375, Float64(a * Float64(c / Float64(b * b))), -0.5)))) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(-1.0546875 * N[(a * N[(N[(N[(c * c), $MachinePrecision] * N[(N[(a * a), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5625 * N[(N[(N[(a * a), $MachinePrecision] * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] + N[(c * N[(-0.375 * N[(a * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot \left(b \cdot b\right)\right)\\
\frac{\mathsf{fma}\left(-1.0546875, a \cdot \frac{\left(c \cdot c\right) \cdot \left(\left(a \cdot a\right) \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot t\_0\right)}, \mathsf{fma}\left(-0.5625, \frac{\left(a \cdot a\right) \cdot \left(c \cdot \left(c \cdot c\right)\right)}{t\_0}, c \cdot \mathsf{fma}\left(-0.375, a \cdot \frac{c}{b \cdot b}, -0.5\right)\right)\right)}{b}
\end{array}
\end{array}
Initial program 19.8%
Taylor expanded in c around 0
Simplified97.1%
Taylor expanded in b around inf
lower-/.f64N/A
Simplified97.4%
Applied egg-rr97.4%
Taylor expanded in c around 0
lower-*.f64N/A
sub-negN/A
metadata-evalN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6497.4
Simplified97.4%
Final simplification97.4%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (/ (* c c) b)))
(/
(/
(*
a
(fma
a
(fma
-4.5
t_0
(fma -1.6875 (/ (* a (* c (* c c))) (* b (* b b))) (* t_0 1.125)))
(* -1.5 (* c b))))
(* b (sqrt (fma 3.0 (* a c) (* b b)))))
(* a 3.0))))
double code(double a, double b, double c) {
double t_0 = (c * c) / b;
return ((a * fma(a, fma(-4.5, t_0, fma(-1.6875, ((a * (c * (c * c))) / (b * (b * b))), (t_0 * 1.125))), (-1.5 * (c * b)))) / (b * sqrt(fma(3.0, (a * c), (b * b))))) / (a * 3.0);
}
function code(a, b, c) t_0 = Float64(Float64(c * c) / b) return Float64(Float64(Float64(a * fma(a, fma(-4.5, t_0, fma(-1.6875, Float64(Float64(a * Float64(c * Float64(c * c))) / Float64(b * Float64(b * b))), Float64(t_0 * 1.125))), Float64(-1.5 * Float64(c * b)))) / Float64(b * sqrt(fma(3.0, Float64(a * c), Float64(b * b))))) / Float64(a * 3.0)) end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(c * c), $MachinePrecision] / b), $MachinePrecision]}, N[(N[(N[(a * N[(a * N[(-4.5 * t$95$0 + N[(-1.6875 * N[(N[(a * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(t$95$0 * 1.125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.5 * N[(c * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[Sqrt[N[(3.0 * N[(a * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 3.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{c \cdot c}{b}\\
\frac{\frac{a \cdot \mathsf{fma}\left(a, \mathsf{fma}\left(-4.5, t\_0, \mathsf{fma}\left(-1.6875, \frac{a \cdot \left(c \cdot \left(c \cdot c\right)\right)}{b \cdot \left(b \cdot b\right)}, t\_0 \cdot 1.125\right)\right), -1.5 \cdot \left(c \cdot b\right)\right)}{b \cdot \sqrt{\mathsf{fma}\left(3, a \cdot c, b \cdot b\right)}}}{a \cdot 3}
\end{array}
\end{array}
Initial program 19.8%
Applied egg-rr19.3%
Taylor expanded in a around 0
lower-*.f64N/A
sub-negN/A
lower-fma.f64N/A
Simplified95.8%
Final simplification95.8%
(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 19.8%
Taylor expanded in b around inf
lower-/.f64N/A
Simplified94.9%
(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(a * Float64(c / Float64(b * b))), -0.5)) / b) end
code[a_, b_, c_] := N[(N[(c * N[(-0.375 * N[(a * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \mathsf{fma}\left(-0.375, a \cdot \frac{c}{b \cdot b}, -0.5\right)}{b}
\end{array}
Initial program 19.8%
Taylor expanded in c around 0
Simplified97.1%
Taylor expanded in b around inf
lower-/.f64N/A
Simplified97.4%
Applied egg-rr97.4%
Taylor expanded in c around 0
lower-*.f64N/A
sub-negN/A
metadata-evalN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6494.8
Simplified94.8%
(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(c * Float64(fma(-0.375, Float64(Float64(a * c) / Float64(b * b)), -0.5) / b)) end
code[a_, b_, c_] := N[(c * N[(N[(-0.375 * N[(N[(a * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + -0.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
c \cdot \frac{\mathsf{fma}\left(-0.375, \frac{a \cdot c}{b \cdot b}, -0.5\right)}{b}
\end{array}
Initial program 19.8%
Taylor expanded in c around 0
Simplified97.1%
Taylor expanded in b around inf
lower-/.f64N/A
sub-negN/A
metadata-evalN/A
lower-fma.f64N/A
lower-/.f64N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6494.5
Simplified94.5%
(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 19.8%
Taylor expanded in b around inf
lower-*.f64N/A
lower-/.f6489.1
Simplified89.1%
herbie shell --seed 2024208
(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)))