
(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 (/ (/ (* (* a c) 4.0) (* a -2.0)) (+ b (sqrt (fma a (* c -4.0) (* b b))))))
double code(double a, double b, double c) {
return (((a * c) * 4.0) / (a * -2.0)) / (b + sqrt(fma(a, (c * -4.0), (b * b))));
}
function code(a, b, c) return Float64(Float64(Float64(Float64(a * c) * 4.0) / Float64(a * -2.0)) / Float64(b + sqrt(fma(a, Float64(c * -4.0), Float64(b * b))))) end
code[a_, b_, c_] := N[(N[(N[(N[(a * c), $MachinePrecision] * 4.0), $MachinePrecision] / N[(a * -2.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\left(a \cdot c\right) \cdot 4}{a \cdot -2}}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}
\end{array}
Initial program 32.5%
Applied rewrites33.2%
Applied rewrites31.0%
Applied rewrites99.4%
Applied rewrites99.5%
Final simplification99.5%
(FPCore (a b c) :precision binary64 (/ (/ (* a (* c -4.0)) (+ b (sqrt (fma a (* c -4.0) (* b b))))) (* a 2.0)))
double code(double a, double b, double c) {
return ((a * (c * -4.0)) / (b + sqrt(fma(a, (c * -4.0), (b * b))))) / (a * 2.0);
}
function code(a, b, c) return Float64(Float64(Float64(a * Float64(c * -4.0)) / Float64(b + sqrt(fma(a, Float64(c * -4.0), Float64(b * b))))) / Float64(a * 2.0)) end
code[a_, b_, c_] := N[(N[(N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{a \cdot \left(c \cdot -4\right)}{b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}}}{a \cdot 2}
\end{array}
Initial program 32.5%
Applied rewrites33.2%
Applied rewrites35.2%
Applied rewrites99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (/ (fma a (* c -4.0) 0.0) (* (+ b (sqrt (fma a (* c -4.0) (* b b)))) (* a 2.0))))
double code(double a, double b, double c) {
return fma(a, (c * -4.0), 0.0) / ((b + sqrt(fma(a, (c * -4.0), (b * b)))) * (a * 2.0));
}
function code(a, b, c) return Float64(fma(a, Float64(c * -4.0), 0.0) / Float64(Float64(b + sqrt(fma(a, Float64(c * -4.0), Float64(b * b)))) * Float64(a * 2.0))) end
code[a_, b_, c_] := N[(N[(a * N[(c * -4.0), $MachinePrecision] + 0.0), $MachinePrecision] / N[(N[(b + N[Sqrt[N[(a * N[(c * -4.0), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(a * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(a, c \cdot -4, 0\right)}{\left(b + \sqrt{\mathsf{fma}\left(a, c \cdot -4, b \cdot b\right)}\right) \cdot \left(a \cdot 2\right)}
\end{array}
Initial program 32.5%
Applied rewrites33.2%
Applied rewrites31.0%
Applied rewrites99.4%
Applied rewrites99.4%
Final simplification99.4%
(FPCore (a b c) :precision binary64 (/ (fma (* c c) (/ a (* b b)) c) (- b)))
double code(double a, double b, double c) {
return fma((c * c), (a / (b * b)), c) / -b;
}
function code(a, b, c) return Float64(fma(Float64(c * c), Float64(a / Float64(b * b)), c) / Float64(-b)) end
code[a_, b_, c_] := N[(N[(N[(c * c), $MachinePrecision] * N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision] / (-b)), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(c \cdot c, \frac{a}{b \cdot b}, c\right)}{-b}
\end{array}
Initial program 32.5%
Taylor expanded in b around inf
distribute-lft-outN/A
associate-/l*N/A
mul-1-negN/A
lower-neg.f64N/A
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
associate-/l*N/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f6490.6
Applied rewrites90.6%
Final simplification90.6%
(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(c / Float64(-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 32.5%
Taylor expanded in b around inf
mul-1-negN/A
distribute-neg-frac2N/A
lower-/.f64N/A
lower-neg.f6480.5
Applied rewrites80.5%
(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 32.5%
Applied rewrites33.2%
Applied rewrites31.0%
Taylor expanded in c around 0
*-commutativeN/A
associate-/r*N/A
associate-*l/N/A
distribute-lft1-inN/A
metadata-evalN/A
associate-*r/N/A
mul0-lftN/A
metadata-evalN/A
lower-/.f643.2
Applied rewrites3.2%
Taylor expanded in b around 0
Applied rewrites3.2%
herbie shell --seed 2024237
(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)))