
(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 4 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
(let* ((t_0 (* 4.0 (* a a))))
(/
(/ (- c) a)
(+
(/ (sqrt (fma a (* c -4.0) (* b b))) (/ t_0 (* a 2.0)))
(/ a (/ t_0 (* b 2.0)))))))
double code(double a, double b, double c) {
double t_0 = 4.0 * (a * a);
return (-c / a) / ((sqrt(fma(a, (c * -4.0), (b * b))) / (t_0 / (a * 2.0))) + (a / (t_0 / (b * 2.0))));
}
function code(a, b, c) t_0 = Float64(4.0 * Float64(a * a)) return Float64(Float64(Float64(-c) / a) / Float64(Float64(sqrt(fma(a, Float64(c * -4.0), Float64(b * b))) / Float64(t_0 / Float64(a * 2.0))) + Float64(a / Float64(t_0 / Float64(b * 2.0))))) end
code[a_, b_, c_] := Block[{t$95$0 = N[(4.0 * N[(a * a), $MachinePrecision]), $MachinePrecision]}, N[(N[((-c) / a), $MachinePrecision] / N[(N[(N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[(t$95$0 / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(a / N[(t$95$0 / N[(b * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 4 \cdot \left(a \cdot a\right)\\
\frac{\frac{-c}{a}}{\frac{\sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}{\frac{t_0}{a \cdot 2}} + \frac{a}{\frac{t_0}{b \cdot 2}}}
\end{array}
\end{array}
Initial program 33.0%
Applied egg-rr32.8%
un-div-inv32.8%
div-sub32.6%
flip--32.3%
Applied egg-rr32.3%
Simplified34.3%
Taylor expanded in a around 0 99.3%
associate-*r/99.3%
neg-mul-199.3%
Simplified99.3%
Final simplification99.3%
(FPCore (a b c) :precision binary64 (/ 2.0 (+ (* -2.0 (/ b c)) (* 2.0 (/ a b)))))
double code(double a, double b, double c) {
return 2.0 / ((-2.0 * (b / c)) + (2.0 * (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 = 2.0d0 / (((-2.0d0) * (b / c)) + (2.0d0 * (a / b)))
end function
public static double code(double a, double b, double c) {
return 2.0 / ((-2.0 * (b / c)) + (2.0 * (a / b)));
}
def code(a, b, c): return 2.0 / ((-2.0 * (b / c)) + (2.0 * (a / b)))
function code(a, b, c) return Float64(2.0 / Float64(Float64(-2.0 * Float64(b / c)) + Float64(2.0 * Float64(a / b)))) end
function tmp = code(a, b, c) tmp = 2.0 / ((-2.0 * (b / c)) + (2.0 * (a / b))); end
code[a_, b_, c_] := N[(2.0 / N[(N[(-2.0 * N[(b / c), $MachinePrecision]), $MachinePrecision] + N[(2.0 * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{-2 \cdot \frac{b}{c} + 2 \cdot \frac{a}{b}}
\end{array}
Initial program 33.0%
Applied egg-rr32.8%
Taylor expanded in a around 0 32.8%
unpow232.8%
Simplified32.8%
associate-*r/32.8%
associate-/l*32.8%
associate-*r*32.8%
associate-*r*32.8%
*-commutative32.8%
distribute-rgt-out--32.8%
associate-/l*32.8%
div-inv32.8%
metadata-eval32.8%
*-commutative32.8%
Applied egg-rr32.8%
Taylor expanded in a around 0 91.4%
Final simplification91.4%
(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 33.0%
Taylor expanded in b around inf 79.9%
associate-*r/79.9%
neg-mul-179.9%
Simplified79.9%
Final simplification79.9%
(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 33.0%
Applied egg-rr32.8%
*-commutative32.8%
sub-neg32.8%
distribute-lft-in32.5%
fma-def34.2%
Applied egg-rr34.2%
Taylor expanded in c around 0 3.2%
distribute-rgt-out3.2%
metadata-eval3.2%
mul0-rgt3.2%
Simplified3.2%
Final simplification3.2%
herbie shell --seed 2023297
(FPCore (a b c)
:name "Quadratic roots, 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) (* (* 4.0 a) c)))) (* 2.0 a)))