
(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 10 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
(/
(fma
(fma
(fma
(/ (- (pow a 3.0)) (pow b 5.0))
(- c)
(/ (* 0.5 (* a a)) (pow b 3.0)))
c
(* (/ a b) 0.5))
c
(* -0.5 b))
c)))
double code(double a, double b, double c) {
return 0.5 / (fma(fma(fma((-pow(a, 3.0) / pow(b, 5.0)), -c, ((0.5 * (a * a)) / pow(b, 3.0))), c, ((a / b) * 0.5)), c, (-0.5 * b)) / c);
}
function code(a, b, c) return Float64(0.5 / Float64(fma(fma(fma(Float64(Float64(-(a ^ 3.0)) / (b ^ 5.0)), Float64(-c), Float64(Float64(0.5 * Float64(a * a)) / (b ^ 3.0))), c, Float64(Float64(a / b) * 0.5)), c, Float64(-0.5 * b)) / c)) end
code[a_, b_, c_] := N[(0.5 / N[(N[(N[(N[(N[((-N[Power[a, 3.0], $MachinePrecision]) / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * (-c) + N[(N[(0.5 * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * c + N[(N[(a / b), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision] * c + N[(-0.5 * b), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{-{a}^{3}}{{b}^{5}}, -c, \frac{0.5 \cdot \left(a \cdot a\right)}{{b}^{3}}\right), c, \frac{a}{b} \cdot 0.5\right), c, -0.5 \cdot b\right)}{c}}
\end{array}
Initial program 31.9%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6431.9
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6431.9
Applied rewrites31.9%
Taylor expanded in c around 0
Applied rewrites95.1%
Taylor expanded in a around 0
Applied rewrites95.1%
(FPCore (a b c)
:precision binary64
(fma
(/
(fma
(* -5.0 (* a a))
(pow c 4.0)
(* (fma (* (- c) c) (* b b) (* (* (pow c 3.0) a) -2.0)) (* b b)))
(pow b 7.0))
a
(/ (- c) b)))
double code(double a, double b, double c) {
return fma((fma((-5.0 * (a * a)), pow(c, 4.0), (fma((-c * c), (b * b), ((pow(c, 3.0) * a) * -2.0)) * (b * b))) / pow(b, 7.0)), a, (-c / b));
}
function code(a, b, c) return fma(Float64(fma(Float64(-5.0 * Float64(a * a)), (c ^ 4.0), Float64(fma(Float64(Float64(-c) * c), Float64(b * b), Float64(Float64((c ^ 3.0) * a) * -2.0)) * Float64(b * b))) / (b ^ 7.0)), a, Float64(Float64(-c) / b)) end
code[a_, b_, c_] := N[(N[(N[(N[(-5.0 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[Power[c, 4.0], $MachinePrecision] + N[(N[(N[((-c) * c), $MachinePrecision] * N[(b * b), $MachinePrecision] + N[(N[(N[Power[c, 3.0], $MachinePrecision] * a), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision] * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision] * a + N[((-c) / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{\mathsf{fma}\left(-5 \cdot \left(a \cdot a\right), {c}^{4}, \mathsf{fma}\left(\left(-c\right) \cdot c, b \cdot b, \left({c}^{3} \cdot a\right) \cdot -2\right) \cdot \left(b \cdot b\right)\right)}{{b}^{7}}, a, \frac{-c}{b}\right)
\end{array}
Initial program 31.9%
Taylor expanded in a around 0
Applied rewrites95.0%
Taylor expanded in b around 0
Applied rewrites95.0%
Taylor expanded in b around 0
Applied rewrites95.0%
(FPCore (a b c) :precision binary64 (/ 0.5 (/ (fma (* 0.5 (fma (* a a) (/ c (pow b 3.0)) (/ a b))) c (* -0.5 b)) c)))
double code(double a, double b, double c) {
return 0.5 / (fma((0.5 * fma((a * a), (c / pow(b, 3.0)), (a / b))), c, (-0.5 * b)) / c);
}
function code(a, b, c) return Float64(0.5 / Float64(fma(Float64(0.5 * fma(Float64(a * a), Float64(c / (b ^ 3.0)), Float64(a / b))), c, Float64(-0.5 * b)) / c)) end
code[a_, b_, c_] := N[(0.5 / N[(N[(N[(0.5 * N[(N[(a * a), $MachinePrecision] * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] + N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * c + N[(-0.5 * b), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\frac{\mathsf{fma}\left(0.5 \cdot \mathsf{fma}\left(a \cdot a, \frac{c}{{b}^{3}}, \frac{a}{b}\right), c, -0.5 \cdot b\right)}{c}}
\end{array}
Initial program 31.9%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6431.9
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6431.9
Applied rewrites31.9%
Taylor expanded in b around inf
*-commutativeN/A
lower-*.f64N/A
Applied rewrites93.4%
Taylor expanded in c around 0
Applied rewrites93.5%
(FPCore (a b c) :precision binary64 (/ 0.5 (fma (fma (* 0.5 (/ c (pow b 3.0))) a (/ 0.5 b)) a (* (/ b c) -0.5))))
double code(double a, double b, double c) {
return 0.5 / fma(fma((0.5 * (c / pow(b, 3.0))), a, (0.5 / b)), a, ((b / c) * -0.5));
}
function code(a, b, c) return Float64(0.5 / fma(fma(Float64(0.5 * Float64(c / (b ^ 3.0))), a, Float64(0.5 / b)), a, Float64(Float64(b / c) * -0.5))) end
code[a_, b_, c_] := N[(0.5 / N[(N[(N[(0.5 * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * a + N[(0.5 / b), $MachinePrecision]), $MachinePrecision] * a + N[(N[(b / c), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\mathsf{fma}\left(\mathsf{fma}\left(0.5 \cdot \frac{c}{{b}^{3}}, a, \frac{0.5}{b}\right), a, \frac{b}{c} \cdot -0.5\right)}
\end{array}
Initial program 31.9%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6431.9
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6431.9
Applied rewrites31.9%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites93.5%
(FPCore (a b c)
:precision binary64
(/
0.5
(*
(+
(/ (/ (* (* c (* a a)) -0.5) (* b b)) (* b b))
(fma (/ a (* b b)) -0.5 (/ 0.5 c)))
(- b))))
double code(double a, double b, double c) {
return 0.5 / ((((((c * (a * a)) * -0.5) / (b * b)) / (b * b)) + fma((a / (b * b)), -0.5, (0.5 / c))) * -b);
}
function code(a, b, c) return Float64(0.5 / Float64(Float64(Float64(Float64(Float64(Float64(c * Float64(a * a)) * -0.5) / Float64(b * b)) / Float64(b * b)) + fma(Float64(a / Float64(b * b)), -0.5, Float64(0.5 / c))) * Float64(-b))) end
code[a_, b_, c_] := N[(0.5 / N[(N[(N[(N[(N[(N[(c * N[(a * a), $MachinePrecision]), $MachinePrecision] * -0.5), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision] * -0.5 + N[(0.5 / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * (-b)), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\left(\frac{\frac{\left(c \cdot \left(a \cdot a\right)\right) \cdot -0.5}{b \cdot b}}{b \cdot b} + \mathsf{fma}\left(\frac{a}{b \cdot b}, -0.5, \frac{0.5}{c}\right)\right) \cdot \left(-b\right)}
\end{array}
Initial program 31.9%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6431.9
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6431.9
Applied rewrites31.9%
Taylor expanded in b around inf
*-commutativeN/A
lower-*.f64N/A
Applied rewrites93.4%
Applied rewrites93.4%
Final simplification93.4%
(FPCore (a b c) :precision binary64 (/ 0.5 (/ (fma (* a (/ c b)) 0.5 (* -0.5 b)) c)))
double code(double a, double b, double c) {
return 0.5 / (fma((a * (c / b)), 0.5, (-0.5 * b)) / c);
}
function code(a, b, c) return Float64(0.5 / Float64(fma(Float64(a * Float64(c / b)), 0.5, Float64(-0.5 * b)) / c)) end
code[a_, b_, c_] := N[(0.5 / N[(N[(N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision] * 0.5 + N[(-0.5 * b), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\frac{\mathsf{fma}\left(a \cdot \frac{c}{b}, 0.5, -0.5 \cdot b\right)}{c}}
\end{array}
Initial program 31.9%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6431.9
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6431.9
Applied rewrites31.9%
Taylor expanded in c around 0
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
lower-*.f6490.3
Applied rewrites90.3%
(FPCore (a b c) :precision binary64 (/ 0.5 (fma (/ a b) 0.5 (* (/ b c) -0.5))))
double code(double a, double b, double c) {
return 0.5 / fma((a / b), 0.5, ((b / c) * -0.5));
}
function code(a, b, c) return Float64(0.5 / fma(Float64(a / b), 0.5, Float64(Float64(b / c) * -0.5))) end
code[a_, b_, c_] := N[(0.5 / N[(N[(a / b), $MachinePrecision] * 0.5 + N[(N[(b / c), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\mathsf{fma}\left(\frac{a}{b}, 0.5, \frac{b}{c} \cdot -0.5\right)}
\end{array}
Initial program 31.9%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6431.9
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6431.9
Applied rewrites31.9%
Taylor expanded in a around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-/.f6490.3
Applied rewrites90.3%
(FPCore (a b c) :precision binary64 (/ (* (fma (- a) (/ c (* b b)) -1.0) c) b))
double code(double a, double b, double c) {
return (fma(-a, (c / (b * b)), -1.0) * c) / b;
}
function code(a, b, c) return Float64(Float64(fma(Float64(-a), Float64(c / Float64(b * b)), -1.0) * c) / b) end
code[a_, b_, c_] := N[(N[(N[((-a) * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision] * c), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(-a, \frac{c}{b \cdot b}, -1\right) \cdot c}{b}
\end{array}
Initial program 31.9%
Taylor expanded in b around inf
lower-/.f64N/A
Applied rewrites93.4%
Taylor expanded in c around 0
Applied rewrites90.1%
(FPCore (a b c) :precision binary64 (* (/ (- -1.0 (/ (* c a) (* b b))) b) c))
double code(double a, double b, double c) {
return ((-1.0 - ((c * a) / (b * b))) / b) * c;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (((-1.0d0) - ((c * a) / (b * b))) / b) * c
end function
public static double code(double a, double b, double c) {
return ((-1.0 - ((c * a) / (b * b))) / b) * c;
}
def code(a, b, c): return ((-1.0 - ((c * a) / (b * b))) / b) * c
function code(a, b, c) return Float64(Float64(Float64(-1.0 - Float64(Float64(c * a) / Float64(b * b))) / b) * c) end
function tmp = code(a, b, c) tmp = ((-1.0 - ((c * a) / (b * b))) / b) * c; end
code[a_, b_, c_] := N[(N[(N[(-1.0 - N[(N[(c * a), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision] * c), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1 - \frac{c \cdot a}{b \cdot b}}{b} \cdot c
\end{array}
Initial program 31.9%
Taylor expanded in c around 0
*-commutativeN/A
sub-negN/A
distribute-neg-fracN/A
metadata-evalN/A
associate-*r/N/A
associate-*r*N/A
associate-*l/N/A
associate-*r/N/A
lower-*.f64N/A
Applied rewrites89.9%
Applied rewrites89.9%
(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 31.9%
Taylor expanded in a around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6480.9
Applied rewrites80.9%
herbie shell --seed 2024327
(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)))