
(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 7 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
(/
1.0
(fma
-2.0
(/ b c)
(*
a
(fma
a
(*
-3.0
(+
(* a (* -0.5625 (/ (pow c 2.0) (pow b 5.0))))
(* (/ c (pow b 3.0)) -0.375)))
(/ 1.5 b))))))
double code(double a, double b, double c) {
return 1.0 / fma(-2.0, (b / c), (a * fma(a, (-3.0 * ((a * (-0.5625 * (pow(c, 2.0) / pow(b, 5.0)))) + ((c / pow(b, 3.0)) * -0.375))), (1.5 / b))));
}
function code(a, b, c) return Float64(1.0 / fma(-2.0, Float64(b / c), Float64(a * fma(a, Float64(-3.0 * Float64(Float64(a * Float64(-0.5625 * Float64((c ^ 2.0) / (b ^ 5.0)))) + Float64(Float64(c / (b ^ 3.0)) * -0.375))), Float64(1.5 / b))))) end
code[a_, b_, c_] := N[(1.0 / N[(-2.0 * N[(b / c), $MachinePrecision] + N[(a * N[(a * N[(-3.0 * N[(N[(a * N[(-0.5625 * N[(N[Power[c, 2.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] * -0.375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.5 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(-2, \frac{b}{c}, a \cdot \mathsf{fma}\left(a, -3 \cdot \left(a \cdot \left(-0.5625 \cdot \frac{{c}^{2}}{{b}^{5}}\right) + \frac{c}{{b}^{3}} \cdot -0.375\right), \frac{1.5}{b}\right)\right)}
\end{array}
Initial program 33.8%
/-rgt-identity33.8%
metadata-eval33.8%
Simplified33.8%
Taylor expanded in a around inf 33.7%
clear-num33.7%
inv-pow33.7%
*-commutative33.7%
*-commutative33.7%
fma-define33.7%
Applied egg-rr33.7%
unpow-133.7%
Simplified33.7%
Taylor expanded in a around 0 94.4%
Simplified94.4%
Taylor expanded in c around 0 94.4%
(FPCore (a b c)
:precision binary64
(/
1.0
(/
(fma
-2.0
b
(*
c
(fma -3.0 (* c (* -0.375 (/ (pow a 2.0) (pow b 3.0)))) (/ (* a 1.5) b))))
c)))
double code(double a, double b, double c) {
return 1.0 / (fma(-2.0, b, (c * fma(-3.0, (c * (-0.375 * (pow(a, 2.0) / pow(b, 3.0)))), ((a * 1.5) / b)))) / c);
}
function code(a, b, c) return Float64(1.0 / Float64(fma(-2.0, b, Float64(c * fma(-3.0, Float64(c * Float64(-0.375 * Float64((a ^ 2.0) / (b ^ 3.0)))), Float64(Float64(a * 1.5) / b)))) / c)) end
code[a_, b_, c_] := N[(1.0 / N[(N[(-2.0 * b + N[(c * N[(-3.0 * N[(c * N[(-0.375 * N[(N[Power[a, 2.0], $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(a * 1.5), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{\mathsf{fma}\left(-2, b, c \cdot \mathsf{fma}\left(-3, c \cdot \left(-0.375 \cdot \frac{{a}^{2}}{{b}^{3}}\right), \frac{a \cdot 1.5}{b}\right)\right)}{c}}
\end{array}
Initial program 33.8%
/-rgt-identity33.8%
metadata-eval33.8%
Simplified33.8%
Taylor expanded in a around inf 33.7%
clear-num33.7%
inv-pow33.7%
*-commutative33.7%
*-commutative33.7%
fma-define33.7%
Applied egg-rr33.7%
unpow-133.7%
Simplified33.7%
Taylor expanded in c around 0 92.6%
fma-define92.6%
fma-define92.6%
distribute-rgt-out92.6%
metadata-eval92.6%
associate-*r/92.6%
*-commutative92.6%
Simplified92.6%
Final simplification92.6%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (/ c (pow b 3.0))))
(/
1.0
(+
(* -2.0 (/ b c))
(*
a
(+ (* -3.0 (* a (+ (* t_0 -0.75) (* t_0 0.375)))) (* 1.5 (/ 1.0 b))))))))
double code(double a, double b, double c) {
double t_0 = c / pow(b, 3.0);
return 1.0 / ((-2.0 * (b / c)) + (a * ((-3.0 * (a * ((t_0 * -0.75) + (t_0 * 0.375)))) + (1.5 * (1.0 / b)))));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: t_0
t_0 = c / (b ** 3.0d0)
code = 1.0d0 / (((-2.0d0) * (b / c)) + (a * (((-3.0d0) * (a * ((t_0 * (-0.75d0)) + (t_0 * 0.375d0)))) + (1.5d0 * (1.0d0 / b)))))
end function
public static double code(double a, double b, double c) {
double t_0 = c / Math.pow(b, 3.0);
return 1.0 / ((-2.0 * (b / c)) + (a * ((-3.0 * (a * ((t_0 * -0.75) + (t_0 * 0.375)))) + (1.5 * (1.0 / b)))));
}
def code(a, b, c): t_0 = c / math.pow(b, 3.0) return 1.0 / ((-2.0 * (b / c)) + (a * ((-3.0 * (a * ((t_0 * -0.75) + (t_0 * 0.375)))) + (1.5 * (1.0 / b)))))
function code(a, b, c) t_0 = Float64(c / (b ^ 3.0)) return Float64(1.0 / Float64(Float64(-2.0 * Float64(b / c)) + Float64(a * Float64(Float64(-3.0 * Float64(a * Float64(Float64(t_0 * -0.75) + Float64(t_0 * 0.375)))) + Float64(1.5 * Float64(1.0 / b)))))) end
function tmp = code(a, b, c) t_0 = c / (b ^ 3.0); tmp = 1.0 / ((-2.0 * (b / c)) + (a * ((-3.0 * (a * ((t_0 * -0.75) + (t_0 * 0.375)))) + (1.5 * (1.0 / b))))); end
code[a_, b_, c_] := Block[{t$95$0 = N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]}, N[(1.0 / N[(N[(-2.0 * N[(b / c), $MachinePrecision]), $MachinePrecision] + N[(a * N[(N[(-3.0 * N[(a * N[(N[(t$95$0 * -0.75), $MachinePrecision] + N[(t$95$0 * 0.375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.5 * N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{c}{{b}^{3}}\\
\frac{1}{-2 \cdot \frac{b}{c} + a \cdot \left(-3 \cdot \left(a \cdot \left(t\_0 \cdot -0.75 + t\_0 \cdot 0.375\right)\right) + 1.5 \cdot \frac{1}{b}\right)}
\end{array}
\end{array}
Initial program 33.8%
/-rgt-identity33.8%
metadata-eval33.8%
Simplified33.8%
Taylor expanded in a around inf 33.7%
clear-num33.7%
inv-pow33.7%
*-commutative33.7%
*-commutative33.7%
fma-define33.7%
Applied egg-rr33.7%
unpow-133.7%
Simplified33.7%
Taylor expanded in a around 0 92.6%
Final simplification92.6%
(FPCore (a b c) :precision binary64 (/ 1.0 (/ (+ (* -2.0 b) (* 1.5 (/ (* c a) b))) c)))
double code(double a, double b, double c) {
return 1.0 / (((-2.0 * b) + (1.5 * ((c * a) / 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 = 1.0d0 / ((((-2.0d0) * b) + (1.5d0 * ((c * a) / b))) / c)
end function
public static double code(double a, double b, double c) {
return 1.0 / (((-2.0 * b) + (1.5 * ((c * a) / b))) / c);
}
def code(a, b, c): return 1.0 / (((-2.0 * b) + (1.5 * ((c * a) / b))) / c)
function code(a, b, c) return Float64(1.0 / Float64(Float64(Float64(-2.0 * b) + Float64(1.5 * Float64(Float64(c * a) / b))) / c)) end
function tmp = code(a, b, c) tmp = 1.0 / (((-2.0 * b) + (1.5 * ((c * a) / b))) / c); end
code[a_, b_, c_] := N[(1.0 / N[(N[(N[(-2.0 * b), $MachinePrecision] + N[(1.5 * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{-2 \cdot b + 1.5 \cdot \frac{c \cdot a}{b}}{c}}
\end{array}
Initial program 33.8%
/-rgt-identity33.8%
metadata-eval33.8%
Simplified33.8%
Taylor expanded in a around inf 33.7%
clear-num33.7%
inv-pow33.7%
*-commutative33.7%
*-commutative33.7%
fma-define33.7%
Applied egg-rr33.7%
unpow-133.7%
Simplified33.7%
Taylor expanded in c around 0 89.5%
Final simplification89.5%
(FPCore (a b c) :precision binary64 (/ 1.0 (+ (* -2.0 (/ b c)) (* 1.5 (/ a b)))))
double code(double a, double b, double c) {
return 1.0 / ((-2.0 * (b / c)) + (1.5 * (a / b)));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = 1.0d0 / (((-2.0d0) * (b / c)) + (1.5d0 * (a / b)))
end function
public static double code(double a, double b, double c) {
return 1.0 / ((-2.0 * (b / c)) + (1.5 * (a / b)));
}
def code(a, b, c): return 1.0 / ((-2.0 * (b / c)) + (1.5 * (a / b)))
function code(a, b, c) return Float64(1.0 / Float64(Float64(-2.0 * Float64(b / c)) + Float64(1.5 * Float64(a / b)))) end
function tmp = code(a, b, c) tmp = 1.0 / ((-2.0 * (b / c)) + (1.5 * (a / b))); end
code[a_, b_, c_] := N[(1.0 / N[(N[(-2.0 * N[(b / c), $MachinePrecision]), $MachinePrecision] + N[(1.5 * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{-2 \cdot \frac{b}{c} + 1.5 \cdot \frac{a}{b}}
\end{array}
Initial program 33.8%
/-rgt-identity33.8%
metadata-eval33.8%
Simplified33.8%
Taylor expanded in a around inf 33.7%
clear-num33.7%
inv-pow33.7%
*-commutative33.7%
*-commutative33.7%
fma-define33.7%
Applied egg-rr33.7%
unpow-133.7%
Simplified33.7%
Taylor expanded in a around 0 89.5%
(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(Float64(c * -0.5) / b) end
function tmp = code(a, b, c) tmp = (c * -0.5) / b; end
code[a_, b_, c_] := N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot -0.5}{b}
\end{array}
Initial program 33.8%
Taylor expanded in b around inf 79.6%
associate-*r/79.6%
*-commutative79.6%
Simplified79.6%
(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 33.8%
Taylor expanded in b around inf 79.6%
associate-*r/79.6%
*-commutative79.6%
Simplified79.6%
Taylor expanded in c around 0 79.6%
associate-*r/79.6%
*-commutative79.6%
associate-*r/79.4%
Simplified79.4%
herbie shell --seed 2024135
(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)))