
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * 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) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * 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) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(fma
-2.0
(/ (pow c 3.0) (/ (pow b 5.0) (* a a)))
(-
(-
(* (/ -0.25 (pow b 7.0)) (/ (pow (* c a) 4.0) (/ a 20.0)))
(/ a (/ (pow b 3.0) (* c c))))
(/ c b))))
double code(double a, double b, double c) {
return fma(-2.0, (pow(c, 3.0) / (pow(b, 5.0) / (a * a))), ((((-0.25 / pow(b, 7.0)) * (pow((c * a), 4.0) / (a / 20.0))) - (a / (pow(b, 3.0) / (c * c)))) - (c / b)));
}
function code(a, b, c) return fma(-2.0, Float64((c ^ 3.0) / Float64((b ^ 5.0) / Float64(a * a))), Float64(Float64(Float64(Float64(-0.25 / (b ^ 7.0)) * Float64((Float64(c * a) ^ 4.0) / Float64(a / 20.0))) - Float64(a / Float64((b ^ 3.0) / Float64(c * c)))) - Float64(c / b))) end
code[a_, b_, c_] := N[(-2.0 * N[(N[Power[c, 3.0], $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(-0.25 / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision] * N[(N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision] / N[(a / 20.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(a / N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \left(\frac{-0.25}{{b}^{7}} \cdot \frac{{\left(c \cdot a\right)}^{4}}{\frac{a}{20}} - \frac{a}{\frac{{b}^{3}}{c \cdot c}}\right) - \frac{c}{b}\right)
\end{array}
Initial program 19.4%
Simplified19.4%
*-commutative19.4%
metadata-eval19.4%
distribute-lft-neg-in19.4%
distribute-rgt-neg-in19.4%
*-commutative19.4%
fma-neg19.4%
associate-*l*19.4%
Applied egg-rr19.4%
div-sub19.1%
cancel-sign-sub-inv19.1%
metadata-eval19.1%
Applied egg-rr19.1%
Taylor expanded in b around inf 97.4%
Simplified97.4%
Final simplification97.4%
(FPCore (a b c) :precision binary64 (- (- (/ (* -2.0 (* a a)) (/ (pow b 5.0) (pow c 3.0))) (/ c b)) (* (* c c) (/ a (pow b 3.0)))))
double code(double a, double b, double c) {
return (((-2.0 * (a * a)) / (pow(b, 5.0) / pow(c, 3.0))) - (c / b)) - ((c * c) * (a / pow(b, 3.0)));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((((-2.0d0) * (a * a)) / ((b ** 5.0d0) / (c ** 3.0d0))) - (c / b)) - ((c * c) * (a / (b ** 3.0d0)))
end function
public static double code(double a, double b, double c) {
return (((-2.0 * (a * a)) / (Math.pow(b, 5.0) / Math.pow(c, 3.0))) - (c / b)) - ((c * c) * (a / Math.pow(b, 3.0)));
}
def code(a, b, c): return (((-2.0 * (a * a)) / (math.pow(b, 5.0) / math.pow(c, 3.0))) - (c / b)) - ((c * c) * (a / math.pow(b, 3.0)))
function code(a, b, c) return Float64(Float64(Float64(Float64(-2.0 * Float64(a * a)) / Float64((b ^ 5.0) / (c ^ 3.0))) - Float64(c / b)) - Float64(Float64(c * c) * Float64(a / (b ^ 3.0)))) end
function tmp = code(a, b, c) tmp = (((-2.0 * (a * a)) / ((b ^ 5.0) / (c ^ 3.0))) - (c / b)) - ((c * c) * (a / (b ^ 3.0))); end
code[a_, b_, c_] := N[(N[(N[(N[(-2.0 * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] * N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{-2 \cdot \left(a \cdot a\right)}{\frac{{b}^{5}}{{c}^{3}}} - \frac{c}{b}\right) - \left(c \cdot c\right) \cdot \frac{a}{{b}^{3}}
\end{array}
Initial program 19.4%
Taylor expanded in b around inf 96.0%
associate-+r+96.0%
mul-1-neg96.0%
unsub-neg96.0%
mul-1-neg96.0%
unsub-neg96.0%
associate-/l*96.0%
associate-*r/96.0%
unpow296.0%
associate-/l*96.0%
associate-/r/96.0%
unpow296.0%
Simplified96.0%
Final simplification96.0%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (* (* c c) (/ a (pow b 3.0)))))
double code(double a, double b, double c) {
return (-c / b) - ((c * c) * (a / pow(b, 3.0)));
}
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) - ((c * c) * (a / (b ** 3.0d0)))
end function
public static double code(double a, double b, double c) {
return (-c / b) - ((c * c) * (a / Math.pow(b, 3.0)));
}
def code(a, b, c): return (-c / b) - ((c * c) * (a / math.pow(b, 3.0)))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(Float64(c * c) * Float64(a / (b ^ 3.0)))) end
function tmp = code(a, b, c) tmp = (-c / b) - ((c * c) * (a / (b ^ 3.0))); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] * N[(a / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - \left(c \cdot c\right) \cdot \frac{a}{{b}^{3}}
\end{array}
Initial program 19.4%
Taylor expanded in b around inf 93.7%
mul-1-neg93.7%
unsub-neg93.7%
mul-1-neg93.7%
distribute-neg-frac93.7%
associate-/l*93.7%
associate-/r/93.7%
unpow293.7%
Simplified93.7%
Final simplification93.7%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (/ (* a (* c c)) (pow b 3.0))))
double code(double a, double b, double c) {
return (-c / b) - ((a * (c * c)) / pow(b, 3.0));
}
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) - ((a * (c * c)) / (b ** 3.0d0))
end function
public static double code(double a, double b, double c) {
return (-c / b) - ((a * (c * c)) / Math.pow(b, 3.0));
}
def code(a, b, c): return (-c / b) - ((a * (c * c)) / math.pow(b, 3.0))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(Float64(a * Float64(c * c)) / (b ^ 3.0))) end
function tmp = code(a, b, c) tmp = (-c / b) - ((a * (c * c)) / (b ^ 3.0)); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(N[(a * N[(c * c), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - \frac{a \cdot \left(c \cdot c\right)}{{b}^{3}}
\end{array}
Initial program 19.4%
Taylor expanded in b around inf 93.7%
mul-1-neg93.7%
unsub-neg93.7%
mul-1-neg93.7%
distribute-neg-frac93.7%
associate-/l*93.7%
associate-/r/93.7%
unpow293.7%
Simplified93.7%
associate-*l/93.7%
Applied egg-rr93.7%
Final simplification93.7%
(FPCore (a b c) :precision binary64 (/ (- c) b))
double code(double a, double b, double c) {
return -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 = -c / b
end function
public static double code(double a, double b, double c) {
return -c / b;
}
def code(a, b, c): return -c / b
function code(a, b, c) return Float64(Float64(-c) / b) end
function tmp = code(a, b, c) tmp = -c / b; end
code[a_, b_, c_] := N[((-c) / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b}
\end{array}
Initial program 19.4%
Taylor expanded in b around inf 89.1%
mul-1-neg89.1%
distribute-neg-frac89.1%
Simplified89.1%
Final simplification89.1%
herbie shell --seed 2023271
(FPCore (a b c)
:name "Quadratic roots, 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) (* (* 4.0 a) c)))) (* 2.0 a)))