
(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 10 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
(* -0.5625 (* a a))
(* (/ c (* b b)) (/ (* c c) (* b b)))
(fma
(/ -0.16666666666666666 a)
(* (/ 6.328125 (pow b 6.0)) (* (pow c 4.0) (pow a 4.0)))
(fma (/ (* -0.375 a) b) (/ (* c c) b) (* -0.5 c))))
b))
double code(double a, double b, double c) {
return fma((-0.5625 * (a * a)), ((c / (b * b)) * ((c * c) / (b * b))), fma((-0.16666666666666666 / a), ((6.328125 / pow(b, 6.0)) * (pow(c, 4.0) * pow(a, 4.0))), fma(((-0.375 * a) / b), ((c * c) / b), (-0.5 * c)))) / b;
}
function code(a, b, c) return Float64(fma(Float64(-0.5625 * Float64(a * a)), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), fma(Float64(-0.16666666666666666 / a), Float64(Float64(6.328125 / (b ^ 6.0)) * Float64((c ^ 4.0) * (a ^ 4.0))), fma(Float64(Float64(-0.375 * a) / b), Float64(Float64(c * c) / b), Float64(-0.5 * c)))) / b) end
code[a_, b_, c_] := N[(N[(N[(-0.5625 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-0.16666666666666666 / a), $MachinePrecision] * N[(N[(6.328125 / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] * N[(N[Power[c, 4.0], $MachinePrecision] * N[Power[a, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(-0.375 * a), $MachinePrecision] / b), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / b), $MachinePrecision] + N[(-0.5 * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.16666666666666666}{a}, \frac{6.328125}{{b}^{6}} \cdot \left({c}^{4} \cdot {a}^{4}\right), \mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{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
(* -0.5625 (* a a))
(* (/ c (* b b)) (/ (* c c) (* b b)))
(*
(fma
(*
(fma (/ (* (* c a) (* c a)) (pow b 6.0)) -1.0546875 (/ -0.375 (* b b)))
a)
c
-0.5)
c))
b))
double code(double a, double b, double c) {
return fma((-0.5625 * (a * a)), ((c / (b * b)) * ((c * c) / (b * b))), (fma((fma((((c * a) * (c * a)) / pow(b, 6.0)), -1.0546875, (-0.375 / (b * b))) * a), c, -0.5) * c)) / b;
}
function code(a, b, c) return Float64(fma(Float64(-0.5625 * Float64(a * a)), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), Float64(fma(Float64(fma(Float64(Float64(Float64(c * a) * Float64(c * a)) / (b ^ 6.0)), -1.0546875, Float64(-0.375 / Float64(b * b))) * a), c, -0.5) * c)) / b) end
code[a_, b_, c_] := N[(N[(N[(-0.5625 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(N[(N[(N[(c * a), $MachinePrecision] * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] * -1.0546875 + N[(-0.375 / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision] * c + -0.5), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\mathsf{fma}\left(\frac{\left(c \cdot a\right) \cdot \left(c \cdot a\right)}{{b}^{6}}, -1.0546875, \frac{-0.375}{b \cdot b}\right) \cdot a, c, -0.5\right) \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 c around 0
Applied rewrites95.7%
Taylor expanded in a around 0
Applied rewrites95.7%
Final simplification95.7%
(FPCore (a b c) :precision binary64 (/ (fma (* -0.5625 (* a a)) (* (/ c (* b b)) (/ (* c c) (* b b))) (* (fma (* (/ a (* b b)) -0.375) c -0.5) c)) b))
double code(double a, double b, double c) {
return fma((-0.5625 * (a * a)), ((c / (b * b)) * ((c * c) / (b * b))), (fma(((a / (b * b)) * -0.375), c, -0.5) * c)) / b;
}
function code(a, b, c) return Float64(fma(Float64(-0.5625 * Float64(a * a)), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), Float64(fma(Float64(Float64(a / Float64(b * b)) * -0.375), c, -0.5) * c)) / b) end
code[a_, b_, c_] := N[(N[(N[(-0.5625 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * -0.375), $MachinePrecision] * c + -0.5), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(-0.5625 \cdot \left(a \cdot a\right), \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\frac{a}{b \cdot b} \cdot -0.375, c, -0.5\right) \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 c around 0
Applied rewrites95.7%
Taylor expanded in a around 0
Applied rewrites94.7%
Final simplification94.7%
(FPCore (a b c)
:precision binary64
(/
(*
(fma
(/ (/ (fma (* (* (/ a (* b b)) c) a) -0.5625 (* -0.375 a)) b) b)
c
-0.5)
c)
b))
double code(double a, double b, double c) {
return (fma(((fma((((a / (b * b)) * c) * a), -0.5625, (-0.375 * a)) / b) / b), c, -0.5) * c) / b;
}
function code(a, b, c) return Float64(Float64(fma(Float64(Float64(fma(Float64(Float64(Float64(a / Float64(b * b)) * c) * a), -0.5625, Float64(-0.375 * a)) / b) / b), c, -0.5) * c) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(N[(N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision] * a), $MachinePrecision] * -0.5625 + N[(-0.375 * a), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision] / b), $MachinePrecision] * c + -0.5), $MachinePrecision] * c), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\frac{\frac{\mathsf{fma}\left(\left(\frac{a}{b \cdot b} \cdot c\right) \cdot a, -0.5625, -0.375 \cdot a\right)}{b}}{b}, c, -0.5\right) \cdot c}{b}
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
Applied rewrites95.7%
Taylor expanded in c around 0
Applied rewrites94.6%
Taylor expanded in b around inf
Applied rewrites94.6%
Final simplification94.6%
(FPCore (a b c) :precision binary64 (/ 0.3333333333333333 (fma (/ (fma (/ (* 0.375 a) b) (/ c b) 0.5) b) a (* -0.6666666666666666 (/ b c)))))
double code(double a, double b, double c) {
return 0.3333333333333333 / fma((fma(((0.375 * a) / b), (c / b), 0.5) / b), a, (-0.6666666666666666 * (b / c)));
}
function code(a, b, c) return Float64(0.3333333333333333 / fma(Float64(fma(Float64(Float64(0.375 * a) / b), Float64(c / b), 0.5) / b), a, Float64(-0.6666666666666666 * Float64(b / c)))) end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(N[(N[(N[(N[(0.375 * a), $MachinePrecision] / b), $MachinePrecision] * N[(c / b), $MachinePrecision] + 0.5), $MachinePrecision] / b), $MachinePrecision] * a + N[(-0.6666666666666666 * N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.3333333333333333}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\frac{0.375 \cdot a}{b}, \frac{c}{b}, 0.5\right)}{b}, a, -0.6666666666666666 \cdot \frac{b}{c}\right)}
\end{array}
Initial program 23.0%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6423.0
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6423.0
Applied rewrites23.0%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites94.5%
Taylor expanded in b around inf
Applied rewrites94.5%
Final simplification94.5%
(FPCore (a b c) :precision binary64 (/ (fma (/ (* -0.375 a) b) (/ (* c c) b) (* -0.5 c)) b))
double code(double a, double b, double c) {
return fma(((-0.375 * a) / b), ((c * c) / b), (-0.5 * c)) / b;
}
function code(a, b, c) return Float64(fma(Float64(Float64(-0.375 * a) / b), Float64(Float64(c * c) / b), Float64(-0.5 * c)) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(-0.375 * a), $MachinePrecision] / b), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / b), $MachinePrecision] + N[(-0.5 * c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\frac{-0.375 \cdot a}{b}, \frac{c \cdot c}{b}, -0.5 \cdot c\right)}{b}
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
lower-/.f64N/A
+-commutativeN/A
associate-*r/N/A
unpow2N/A
associate-*r*N/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%
(FPCore (a b c) :precision binary64 (/ (* (fma (* (/ a (* b b)) -0.375) c -0.5) c) b))
double code(double a, double b, double c) {
return (fma(((a / (b * b)) * -0.375), c, -0.5) * c) / b;
}
function code(a, b, c) return Float64(Float64(fma(Float64(Float64(a / Float64(b * b)) * -0.375), c, -0.5) * c) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * -0.375), $MachinePrecision] * c + -0.5), $MachinePrecision] * c), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\frac{a}{b \cdot b} \cdot -0.375, c, -0.5\right) \cdot c}{b}
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
Applied rewrites95.7%
Taylor expanded in c around 0
Applied rewrites94.6%
Taylor expanded in a around 0
Applied rewrites92.5%
(FPCore (a b c) :precision binary64 (* (/ (fma (* (/ a (* b b)) c) -0.375 -0.5) b) c))
double code(double a, double b, double c) {
return (fma(((a / (b * b)) * c), -0.375, -0.5) / b) * c;
}
function code(a, b, c) return Float64(Float64(fma(Float64(Float64(a / Float64(b * b)) * c), -0.375, -0.5) / b) * c) end
code[a_, b_, c_] := N[(N[(N[(N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * c), $MachinePrecision] * -0.375 + -0.5), $MachinePrecision] / b), $MachinePrecision] * c), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\frac{a}{b \cdot b} \cdot c, -0.375, -0.5\right)}{b} \cdot c
\end{array}
Initial program 23.0%
Taylor expanded in b around inf
Applied rewrites95.7%
Applied rewrites95.7%
Taylor expanded in c around 0
*-commutativeN/A
*-commutativeN/A
*-commutativeN/A
associate-/l*N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites92.2%
Final simplification92.2%
(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
lower-*.f64N/A
lower-/.f6486.6
Applied rewrites86.6%
Final simplification86.6%
(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%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6423.0
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6423.0
Applied rewrites23.0%
lift-/.f64N/A
lift-/.f64N/A
associate-/r/N/A
lift--.f64N/A
sub-negN/A
distribute-lft-inN/A
lower-+.f64N/A
lower-*.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-/.f64N/A
lower-neg.f6422.7
Applied rewrites22.7%
Taylor expanded in a around 0
distribute-rgt-outN/A
metadata-evalN/A
associate-*l/N/A
mul0-rgt3.3
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)))