
(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
(/
(fma
(* (* a a) -0.5625)
(* (/ (* c c) (* b b)) (/ c (* b b)))
(fma
(/ -0.16666666666666666 (pow b 6.0))
(* (* (pow a 4.0) (pow c 4.0)) (/ 6.328125 a))
(fma (/ -0.375 b) (/ (* (* c c) a) b) (* -0.5 c))))
b))
double code(double a, double b, double c) {
return fma(((a * a) * -0.5625), (((c * c) / (b * b)) * (c / (b * b))), fma((-0.16666666666666666 / pow(b, 6.0)), ((pow(a, 4.0) * pow(c, 4.0)) * (6.328125 / a)), fma((-0.375 / b), (((c * c) * a) / b), (-0.5 * c)))) / b;
}
function code(a, b, c) return Float64(fma(Float64(Float64(a * a) * -0.5625), Float64(Float64(Float64(c * c) / Float64(b * b)) * Float64(c / Float64(b * b))), fma(Float64(-0.16666666666666666 / (b ^ 6.0)), Float64(Float64((a ^ 4.0) * (c ^ 4.0)) * Float64(6.328125 / a)), fma(Float64(-0.375 / b), Float64(Float64(Float64(c * c) * a) / b), Float64(-0.5 * c)))) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] * N[(N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-0.16666666666666666 / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] * N[(N[(N[Power[a, 4.0], $MachinePrecision] * N[Power[c, 4.0], $MachinePrecision]), $MachinePrecision] * N[(6.328125 / a), $MachinePrecision]), $MachinePrecision] + N[(N[(-0.375 / b), $MachinePrecision] * N[(N[(N[(c * c), $MachinePrecision] * a), $MachinePrecision] / b), $MachinePrecision] + N[(-0.5 * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{{b}^{6}}, \left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{a}, \mathsf{fma}\left(\frac{-0.375}{b}, \frac{\left(c \cdot c\right) \cdot a}{b}, -0.5 \cdot c\right)\right)\right)}{b}
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
Applied rewrites95.7%
Applied rewrites95.7%
Final simplification95.7%
(FPCore (a b c)
:precision binary64
(/
(fma
(* (* a a) -0.5625)
(* (/ (* c c) (* b b)) (/ c (* b b)))
(fma
(*
(- (/ (* -1.0546875 (* (* (* a a) c) c)) (pow b 6.0)) (/ 0.375 (* b b)))
(* c c))
a
(* -0.5 c)))
b))
double code(double a, double b, double c) {
return fma(((a * a) * -0.5625), (((c * c) / (b * b)) * (c / (b * b))), fma(((((-1.0546875 * (((a * a) * c) * c)) / pow(b, 6.0)) - (0.375 / (b * b))) * (c * c)), a, (-0.5 * c))) / b;
}
function code(a, b, c) return Float64(fma(Float64(Float64(a * a) * -0.5625), Float64(Float64(Float64(c * c) / Float64(b * b)) * Float64(c / Float64(b * b))), fma(Float64(Float64(Float64(Float64(-1.0546875 * Float64(Float64(Float64(a * a) * c) * c)) / (b ^ 6.0)) - Float64(0.375 / Float64(b * b))) * Float64(c * c)), a, Float64(-0.5 * c))) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] * N[(N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(N[(-1.0546875 * N[(N[(N[(a * a), $MachinePrecision] * c), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] - N[(0.375 / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision]), $MachinePrecision] * a + N[(-0.5 * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\left(\frac{-1.0546875 \cdot \left(\left(\left(a \cdot a\right) \cdot c\right) \cdot c\right)}{{b}^{6}} - \frac{0.375}{b \cdot b}\right) \cdot \left(c \cdot c\right), a, -0.5 \cdot c\right)\right)}{b}
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
Applied rewrites95.7%
Applied rewrites95.7%
Taylor expanded in a around 0
Applied rewrites95.7%
Taylor expanded in c around 0
Applied rewrites95.7%
Final simplification95.7%
(FPCore (a b c) :precision binary64 (/ (fma (* (* a a) -0.5625) (* (/ (* c c) (* b b)) (/ c (* b b))) (fma (* (/ -0.375 b) (/ (* c c) b)) a (* -0.5 c))) b))
double code(double a, double b, double c) {
return fma(((a * a) * -0.5625), (((c * c) / (b * b)) * (c / (b * b))), fma(((-0.375 / b) * ((c * c) / b)), a, (-0.5 * c))) / b;
}
function code(a, b, c) return Float64(fma(Float64(Float64(a * a) * -0.5625), Float64(Float64(Float64(c * c) / Float64(b * b)) * Float64(c / Float64(b * b))), fma(Float64(Float64(-0.375 / b) * Float64(Float64(c * c) / b)), a, Float64(-0.5 * c))) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(a * a), $MachinePrecision] * -0.5625), $MachinePrecision] * N[(N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(-0.375 / b), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision] * a + N[(-0.5 * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\left(a \cdot a\right) \cdot -0.5625, \frac{c \cdot c}{b \cdot b} \cdot \frac{c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.375}{b} \cdot \frac{c \cdot c}{b}, a, -0.5 \cdot c\right)\right)}{b}
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
Applied rewrites95.7%
Applied rewrites95.7%
Taylor expanded in a around 0
Applied rewrites95.7%
Taylor expanded in a around 0
Applied rewrites94.7%
Final simplification94.7%
(FPCore (a b c) :precision binary64 (/ (fma (* c c) (/ (* -0.375 a) (* b b)) (* -0.5 c)) b))
double code(double a, double b, double c) {
return fma((c * c), ((-0.375 * a) / (b * b)), (-0.5 * c)) / b;
}
function code(a, b, c) return Float64(fma(Float64(c * c), Float64(Float64(-0.375 * a) / Float64(b * b)), Float64(-0.5 * c)) / b) end
code[a_, b_, c_] := N[(N[(N[(c * c), $MachinePrecision] * N[(N[(-0.375 * a), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(c \cdot c, \frac{-0.375 \cdot a}{b \cdot b}, -0.5 \cdot c\right)}{b}
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
Applied rewrites95.7%
Applied rewrites95.7%
Taylor expanded in b around inf
lower-/.f64N/A
+-commutativeN/A
associate-*r/N/A
associate-*r*N/A
unpow2N/A
times-fracN/A
lower-fma.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f64N/A
lower-*.f6492.5
Applied rewrites92.5%
Applied rewrites92.5%
Final simplification92.5%
(FPCore (a b c) :precision binary64 (/ (* (- (* (* a (/ c (* b b))) -0.375) 0.5) c) b))
double code(double a, double b, double c) {
return ((((a * (c / (b * b))) * -0.375) - 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 = ((((a * (c / (b * b))) * (-0.375d0)) - 0.5d0) * c) / b
end function
public static double code(double a, double b, double c) {
return ((((a * (c / (b * b))) * -0.375) - 0.5) * c) / b;
}
def code(a, b, c): return ((((a * (c / (b * b))) * -0.375) - 0.5) * c) / b
function code(a, b, c) return Float64(Float64(Float64(Float64(Float64(a * Float64(c / Float64(b * b))) * -0.375) - 0.5) * c) / b) end
function tmp = code(a, b, c) tmp = ((((a * (c / (b * b))) * -0.375) - 0.5) * c) / b; end
code[a_, b_, c_] := N[(N[(N[(N[(N[(a * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * -0.375), $MachinePrecision] - 0.5), $MachinePrecision] * c), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(\left(a \cdot \frac{c}{b \cdot b}\right) \cdot -0.375 - 0.5\right) \cdot c}{b}
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
Applied rewrites95.7%
Applied rewrites95.7%
Taylor expanded in a around 0
Applied rewrites95.7%
Taylor expanded in c around 0
Applied rewrites92.5%
Final simplification92.5%
(FPCore (a b c) :precision binary64 (* (/ c b) -0.5))
double code(double a, double b, double c) {
return (c / b) * -0.5;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (c / b) * (-0.5d0)
end function
public static double code(double a, double b, double c) {
return (c / b) * -0.5;
}
def code(a, b, c): return (c / b) * -0.5
function code(a, b, c) return Float64(Float64(c / b) * -0.5) end
function tmp = code(a, b, c) tmp = (c / b) * -0.5; end
code[a_, b_, c_] := N[(N[(c / b), $MachinePrecision] * -0.5), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{b} \cdot -0.5
\end{array}
Initial program 23.0%
Taylor expanded in a around 0
*-commutativeN/A
lower-*.f64N/A
lower-/.f6486.6
Applied rewrites86.6%
Final simplification86.6%
(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 23.0%
Taylor expanded in a around 0
*-commutativeN/A
lower-*.f64N/A
lower-/.f6486.6
Applied rewrites86.6%
Applied rewrites86.4%
Final simplification86.4%
(FPCore (a b c) :precision binary64 0.0)
double code(double a, double b, double c) {
return 0.0;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = 0.0d0
end function
public static double code(double a, double b, double c) {
return 0.0;
}
def code(a, b, c): return 0.0
function code(a, b, c) return 0.0 end
function tmp = code(a, b, c) tmp = 0.0; end
code[a_, b_, c_] := 0.0
\begin{array}{l}
\\
0
\end{array}
Initial program 23.0%
Taylor expanded in c around inf
*-commutativeN/A
lower-*.f64N/A
fp-cancel-sub-sign-invN/A
metadata-evalN/A
+-commutativeN/A
lower-fma.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6423.0
Applied rewrites23.0%
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/r*N/A
lower-/.f64N/A
lower-/.f6422.9
lift-+.f64N/A
+-commutativeN/A
lower-+.f6422.9
Applied rewrites22.9%
lift-/.f64N/A
lift-/.f64N/A
lift-+.f64N/A
div-addN/A
div-addN/A
associate-/r*N/A
*-commutativeN/A
lower-+.f64N/A
Applied rewrites23.0%
Taylor expanded in a around 0
div-addN/A
associate-*r/N/A
associate-*r/N/A
fp-cancel-sign-sub-invN/A
metadata-evalN/A
+-inverses3.3
Applied rewrites3.3%
herbie shell --seed 2024332
(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)))