
(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) a) -2.0) (+ b (sqrt (fma -4.0 (* a c) (* b b))))))
double code(double a, double b, double c) {
return (((a * c) / a) * -2.0) / (b + sqrt(fma(-4.0, (a * c), (b * b))));
}
function code(a, b, c) return Float64(Float64(Float64(Float64(a * c) / a) * -2.0) / Float64(b + sqrt(fma(-4.0, Float64(a * c), Float64(b * b))))) end
code[a_, b_, c_] := N[(N[(N[(N[(a * c), $MachinePrecision] / a), $MachinePrecision] * -2.0), $MachinePrecision] / N[(b + N[Sqrt[N[(-4.0 * N[(a * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{a \cdot c}{a} \cdot -2}{b + \sqrt{\mathsf{fma}\left(-4, a \cdot c, b \cdot b\right)}}
\end{array}
Initial program 15.0%
lift-*.f64N/A
lift-*.f64N/A
lift-*.f64N/A
sub-negN/A
lift-*.f64N/A
lower-fma.f64N/A
lift-*.f64N/A
distribute-lft-neg-inN/A
lift-*.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
associate-*l*N/A
lower-*.f64N/A
lower-*.f64N/A
metadata-eval15.1
Applied egg-rr15.1%
Applied egg-rr99.5%
Applied egg-rr99.8%
Final simplification99.8%
(FPCore (a b c) :precision binary64 (/ (* (* a c) 4.0) (* (- (- b) (sqrt (fma -4.0 (* a c) (* b b)))) (* a 2.0))))
double code(double a, double b, double c) {
return ((a * c) * 4.0) / ((-b - sqrt(fma(-4.0, (a * c), (b * b)))) * (a * 2.0));
}
function code(a, b, c) return Float64(Float64(Float64(a * c) * 4.0) / Float64(Float64(Float64(-b) - sqrt(fma(-4.0, Float64(a * c), Float64(b * b)))) * Float64(a * 2.0))) end
code[a_, b_, c_] := N[(N[(N[(a * c), $MachinePrecision] * 4.0), $MachinePrecision] / N[(N[((-b) - N[Sqrt[N[(-4.0 * N[(a * c), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(a * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(a \cdot c\right) \cdot 4}{\left(\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, a \cdot c, b \cdot b\right)}\right) \cdot \left(a \cdot 2\right)}
\end{array}
Initial program 15.0%
lift-*.f64N/A
lift-*.f64N/A
lift-*.f64N/A
sub-negN/A
lift-*.f64N/A
lower-fma.f64N/A
lift-*.f64N/A
distribute-lft-neg-inN/A
lift-*.f64N/A
*-commutativeN/A
distribute-rgt-neg-inN/A
associate-*l*N/A
lower-*.f64N/A
lower-*.f64N/A
metadata-eval15.1
Applied egg-rr15.1%
Applied egg-rr99.5%
Applied egg-rr99.5%
Final simplification99.5%
(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 15.0%
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-*.f6495.4
Simplified95.4%
Final simplification95.4%
(FPCore (a b c) :precision binary64 (/ (* c (fma c a (* b b))) (* b (* b (- b)))))
double code(double a, double b, double c) {
return (c * fma(c, a, (b * b))) / (b * (b * -b));
}
function code(a, b, c) return Float64(Float64(c * fma(c, a, Float64(b * b))) / Float64(b * Float64(b * Float64(-b)))) end
code[a_, b_, c_] := N[(N[(c * N[(c * a + N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * (-b)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \mathsf{fma}\left(c, a, b \cdot b\right)}{b \cdot \left(b \cdot \left(-b\right)\right)}
\end{array}
Initial program 15.0%
Taylor expanded in a around 0
distribute-lft-outN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
associate-/l*N/A
lower-fma.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f64N/A
cube-multN/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
lower-/.f6495.3
Simplified95.3%
Taylor expanded in b around 0
lower-/.f64N/A
distribute-lft-outN/A
mul-1-negN/A
lower-neg.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
cube-multN/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6495.0
Simplified95.0%
Taylor expanded in c around 0
lower-*.f64N/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6495.0
Simplified95.0%
Final simplification95.0%
(FPCore (a b c) :precision binary64 (/ (* c (fma b b (* a c))) (* b (* b (- b)))))
double code(double a, double b, double c) {
return (c * fma(b, b, (a * c))) / (b * (b * -b));
}
function code(a, b, c) return Float64(Float64(c * fma(b, b, Float64(a * c))) / Float64(b * Float64(b * Float64(-b)))) end
code[a_, b_, c_] := N[(N[(c * N[(b * b + N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * (-b)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \mathsf{fma}\left(b, b, a \cdot c\right)}{b \cdot \left(b \cdot \left(-b\right)\right)}
\end{array}
Initial program 15.0%
Taylor expanded in a around 0
distribute-lft-outN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
associate-/l*N/A
lower-fma.f64N/A
lower-/.f64N/A
unpow2N/A
lower-*.f64N/A
cube-multN/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
lower-/.f6495.3
Simplified95.3%
Taylor expanded in b around 0
lower-/.f64N/A
distribute-lft-outN/A
mul-1-negN/A
lower-neg.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
cube-multN/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6495.0
Simplified95.0%
lift-*.f64N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f64N/A
distribute-rgt-outN/A
lower-*.f64N/A
lift-*.f64N/A
lower-fma.f6495.0
Applied egg-rr95.0%
Final simplification95.0%
(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 15.0%
Taylor expanded in b around inf
mul-1-negN/A
distribute-neg-frac2N/A
lower-/.f64N/A
lower-neg.f6492.1
Simplified92.1%
Final simplification92.1%
herbie shell --seed 2024207
(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)))