
(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 (/ (/ (* a c) a) (- (- b) (sqrt (fma (* -3.0 c) a (* b b))))))
double code(double a, double b, double c) {
return ((a * c) / a) / (-b - sqrt(fma((-3.0 * c), a, (b * b))));
}
function code(a, b, c) return Float64(Float64(Float64(a * c) / a) / Float64(Float64(-b) - sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))))) end
code[a_, b_, c_] := N[(N[(N[(a * c), $MachinePrecision] / a), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{a \cdot c}{a}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)}}
\end{array}
Initial program 33.5%
Applied rewrites31.9%
Applied rewrites32.7%
Applied rewrites99.0%
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/r*N/A
lift-/.f64N/A
lift-fma.f64N/A
+-rgt-identityN/A
clear-numN/A
+-rgt-identityN/A
lift-fma.f64N/A
lower-/.f64N/A
Applied rewrites99.5%
Final simplification99.5%
(FPCore (a b c) :precision binary64 (/ -1.0 (* (+ (sqrt (fma (* -3.0 c) a (* b b))) b) (/ 1.0 c))))
double code(double a, double b, double c) {
return -1.0 / ((sqrt(fma((-3.0 * c), a, (b * b))) + b) * (1.0 / c));
}
function code(a, b, c) return Float64(-1.0 / Float64(Float64(sqrt(fma(Float64(-3.0 * c), a, Float64(b * b))) + b) * Float64(1.0 / c))) end
code[a_, b_, c_] := N[(-1.0 / N[(N[(N[Sqrt[N[(N[(-3.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision] * N[(1.0 / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{\left(\sqrt{\mathsf{fma}\left(-3 \cdot c, a, b \cdot b\right)} + b\right) \cdot \frac{1}{c}}
\end{array}
Initial program 33.5%
Applied rewrites31.9%
Applied rewrites32.7%
Applied rewrites99.0%
Taylor expanded in c around 0
lower-/.f6499.3
Applied rewrites99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (/ 0.3333333333333333 (/ (fma (* (/ c b) a) 0.5 (* -0.6666666666666666 b)) c)))
double code(double a, double b, double c) {
return 0.3333333333333333 / (fma(((c / b) * a), 0.5, (-0.6666666666666666 * b)) / c);
}
function code(a, b, c) return Float64(0.3333333333333333 / Float64(fma(Float64(Float64(c / b) * a), 0.5, Float64(-0.6666666666666666 * b)) / c)) end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(N[(N[(N[(c / b), $MachinePrecision] * a), $MachinePrecision] * 0.5 + N[(-0.6666666666666666 * b), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.3333333333333333}{\frac{\mathsf{fma}\left(\frac{c}{b} \cdot a, 0.5, -0.6666666666666666 \cdot b\right)}{c}}
\end{array}
Initial program 33.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6433.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6433.5
Applied rewrites33.5%
Taylor expanded in c around 0
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
lower-*.f6489.9
Applied rewrites89.9%
Final simplification89.9%
(FPCore (a b c) :precision binary64 (/ 1.0 (fma (/ a b) 1.5 (* -2.0 (/ b c)))))
double code(double a, double b, double c) {
return 1.0 / fma((a / b), 1.5, (-2.0 * (b / c)));
}
function code(a, b, c) return Float64(1.0 / fma(Float64(a / b), 1.5, Float64(-2.0 * Float64(b / c)))) end
code[a_, b_, c_] := N[(1.0 / N[(N[(a / b), $MachinePrecision] * 1.5 + N[(-2.0 * N[(b / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(\frac{a}{b}, 1.5, -2 \cdot \frac{b}{c}\right)}
\end{array}
Initial program 33.5%
Applied rewrites31.9%
Applied rewrites32.7%
Applied rewrites99.0%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-/.f6489.8
Applied rewrites89.8%
Final simplification89.8%
(FPCore (a b c) :precision binary64 (/ 0.3333333333333333 (fma (/ a b) 0.5 (* (/ b c) -0.6666666666666666))))
double code(double a, double b, double c) {
return 0.3333333333333333 / fma((a / b), 0.5, ((b / c) * -0.6666666666666666));
}
function code(a, b, c) return Float64(0.3333333333333333 / fma(Float64(a / b), 0.5, Float64(Float64(b / c) * -0.6666666666666666))) end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(N[(a / b), $MachinePrecision] * 0.5 + N[(N[(b / c), $MachinePrecision] * -0.6666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.3333333333333333}{\mathsf{fma}\left(\frac{a}{b}, 0.5, \frac{b}{c} \cdot -0.6666666666666666\right)}
\end{array}
Initial program 33.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6433.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6433.5
Applied rewrites33.5%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-/.f6489.8
Applied rewrites89.8%
(FPCore (a b c) :precision binary64 (/ 0.3333333333333333 (fma -0.6666666666666666 (/ b c) (* (/ a b) 0.5))))
double code(double a, double b, double c) {
return 0.3333333333333333 / fma(-0.6666666666666666, (b / c), ((a / b) * 0.5));
}
function code(a, b, c) return Float64(0.3333333333333333 / fma(-0.6666666666666666, Float64(b / c), Float64(Float64(a / b) * 0.5))) end
code[a_, b_, c_] := N[(0.3333333333333333 / N[(-0.6666666666666666 * N[(b / c), $MachinePrecision] + N[(N[(a / b), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.3333333333333333}{\mathsf{fma}\left(-0.6666666666666666, \frac{b}{c}, \frac{a}{b} \cdot 0.5\right)}
\end{array}
Initial program 33.5%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
lower-/.f6433.5
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6433.5
Applied rewrites33.5%
Taylor expanded in b around inf
*-commutativeN/A
lower-*.f64N/A
sub-negN/A
associate-*r/N/A
*-commutativeN/A
unpow2N/A
times-fracN/A
metadata-evalN/A
associate-*r/N/A
lower-fma.f64N/A
lower-/.f64N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f64N/A
associate-*r/N/A
metadata-evalN/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f6489.8
Applied rewrites89.8%
Applied rewrites89.7%
Taylor expanded in a around 0
lower-fma.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-/.f6489.8
Applied rewrites89.8%
(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 33.5%
Taylor expanded in c around 0
*-commutativeN/A
lower-*.f64N/A
lower-/.f6479.8
Applied rewrites79.8%
Final simplification79.8%
(FPCore (a b c) :precision binary64 (* (/ -0.5 b) c))
double code(double a, double b, double c) {
return (-0.5 / b) * c;
}
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) / b) * c
end function
public static double code(double a, double b, double c) {
return (-0.5 / b) * c;
}
def code(a, b, c): return (-0.5 / b) * c
function code(a, b, c) return Float64(Float64(-0.5 / b) * c) end
function tmp = code(a, b, c) tmp = (-0.5 / b) * c; end
code[a_, b_, c_] := N[(N[(-0.5 / b), $MachinePrecision] * c), $MachinePrecision]
\begin{array}{l}
\\
\frac{-0.5}{b} \cdot c
\end{array}
Initial program 33.5%
Taylor expanded in c around 0
*-commutativeN/A
lower-*.f64N/A
lower-/.f6479.8
Applied rewrites79.8%
Applied rewrites79.6%
Final simplification79.6%
herbie shell --seed 2024270
(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)))