
(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 6 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 (/ 0.5 (/ a (* (/ (* -4.0 c) (+ (sqrt (fma (* c a) -4.0 (* b b))) b)) a))))
double code(double a, double b, double c) {
return 0.5 / (a / (((-4.0 * c) / (sqrt(fma((c * a), -4.0, (b * b))) + b)) * a));
}
function code(a, b, c) return Float64(0.5 / Float64(a / Float64(Float64(Float64(-4.0 * c) / Float64(sqrt(fma(Float64(c * a), -4.0, Float64(b * b))) + b)) * a))) end
code[a_, b_, c_] := N[(0.5 / N[(a / N[(N[(N[(-4.0 * c), $MachinePrecision] / N[(N[Sqrt[N[(N[(c * a), $MachinePrecision] * -4.0 + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\frac{a}{\frac{-4 \cdot c}{\sqrt{\mathsf{fma}\left(c \cdot a, -4, b \cdot b\right)} + b} \cdot a}}
\end{array}
Initial program 33.2%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6433.2
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6433.2
Applied rewrites33.2%
Applied rewrites99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (/ (* (* -4.0 c) a) (* (* 2.0 a) (+ (sqrt (fma (* c a) -4.0 (* b b))) b))))
double code(double a, double b, double c) {
return ((-4.0 * c) * a) / ((2.0 * a) * (sqrt(fma((c * a), -4.0, (b * b))) + b));
}
function code(a, b, c) return Float64(Float64(Float64(-4.0 * c) * a) / Float64(Float64(2.0 * a) * Float64(sqrt(fma(Float64(c * a), -4.0, Float64(b * b))) + b))) end
code[a_, b_, c_] := N[(N[(N[(-4.0 * c), $MachinePrecision] * a), $MachinePrecision] / N[(N[(2.0 * a), $MachinePrecision] * N[(N[Sqrt[N[(N[(c * a), $MachinePrecision] * -4.0 + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-4 \cdot c\right) \cdot a}{\left(2 \cdot a\right) \cdot \left(\sqrt{\mathsf{fma}\left(c \cdot a, -4, b \cdot b\right)} + b\right)}
\end{array}
Initial program 33.2%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6433.2
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6433.2
Applied rewrites33.2%
Applied rewrites99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (/ 0.5 (/ (fma -0.5 b (* (* (/ c b) a) 0.5)) c)))
double code(double a, double b, double c) {
return 0.5 / (fma(-0.5, b, (((c / b) * a) * 0.5)) / c);
}
function code(a, b, c) return Float64(0.5 / Float64(fma(-0.5, b, Float64(Float64(Float64(c / b) * a) * 0.5)) / c)) end
code[a_, b_, c_] := N[(0.5 / N[(N[(-0.5 * b + N[(N[(N[(c / b), $MachinePrecision] * a), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\frac{\mathsf{fma}\left(-0.5, b, \left(\frac{c}{b} \cdot a\right) \cdot 0.5\right)}{c}}
\end{array}
Initial program 33.2%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6433.2
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6433.2
Applied rewrites33.2%
Taylor expanded in c around 0
lower-/.f64N/A
lower-fma.f64N/A
lower-*.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f6489.9
Applied rewrites89.9%
Final simplification89.9%
(FPCore (a b c) :precision binary64 (/ 0.5 (fma -0.5 (/ b c) (* (/ a b) 0.5))))
double code(double a, double b, double c) {
return 0.5 / fma(-0.5, (b / c), ((a / b) * 0.5));
}
function code(a, b, c) return Float64(0.5 / fma(-0.5, Float64(b / c), Float64(Float64(a / b) * 0.5))) end
code[a_, b_, c_] := N[(0.5 / N[(-0.5 * N[(b / c), $MachinePrecision] + N[(N[(a / b), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\mathsf{fma}\left(-0.5, \frac{b}{c}, \frac{a}{b} \cdot 0.5\right)}
\end{array}
Initial program 33.2%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6433.2
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6433.2
Applied rewrites33.2%
Taylor expanded in a around 0
lower-fma.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-/.f6489.9
Applied rewrites89.9%
Final simplification89.9%
(FPCore (a b c) :precision binary64 (/ (fma a (/ (* c c) (* b b)) c) (- b)))
double code(double a, double b, double c) {
return fma(a, ((c * c) / (b * b)), c) / -b;
}
function code(a, b, c) return Float64(fma(a, Float64(Float64(c * c) / Float64(b * b)), c) / Float64(-b)) end
code[a_, b_, c_] := N[(N[(a * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision] / (-b)), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(a, \frac{c \cdot c}{b \cdot b}, c\right)}{-b}
\end{array}
Initial program 33.2%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites95.1%
Taylor expanded in b around 0
Applied rewrites95.1%
Taylor expanded in b around inf
distribute-lft-outN/A
associate-*r/N/A
mul-1-negN/A
lower-neg.f64N/A
lower-/.f64N/A
+-commutativeN/A
associate-/l*N/A
lower-fma.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6489.8
Applied rewrites89.8%
Final simplification89.8%
(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 33.2%
Taylor expanded in a around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6479.9
Applied rewrites79.9%
herbie shell --seed 2024332
(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)))