
(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
(/
(fma
(* (* -2.0 a) a)
(* (/ c (* b b)) (/ (* c c) (* b b)))
(fma
(/ -0.25 a)
(* (/ 20.0 (pow b 6.0)) (* (pow a 4.0) (pow c 4.0)))
(- (fma (/ c b) (/ (* c a) b) c))))
b))
double code(double a, double b, double c) {
return fma(((-2.0 * a) * a), ((c / (b * b)) * ((c * c) / (b * b))), fma((-0.25 / a), ((20.0 / pow(b, 6.0)) * (pow(a, 4.0) * pow(c, 4.0))), -fma((c / b), ((c * a) / b), c))) / b;
}
function code(a, b, c) return Float64(fma(Float64(Float64(-2.0 * a) * a), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), fma(Float64(-0.25 / a), Float64(Float64(20.0 / (b ^ 6.0)) * Float64((a ^ 4.0) * (c ^ 4.0))), Float64(-fma(Float64(c / b), Float64(Float64(c * a) / b), c)))) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(-2.0 * a), $MachinePrecision] * a), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-0.25 / a), $MachinePrecision] * N[(N[(20.0 / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] * N[(N[Power[a, 4.0], $MachinePrecision] * N[Power[c, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + (-N[(N[(c / b), $MachinePrecision] * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision] + c), $MachinePrecision])), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\left(-2 \cdot a\right) \cdot a, \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(\frac{-0.25}{a}, \frac{20}{{b}^{6}} \cdot \left({a}^{4} \cdot {c}^{4}\right), -\mathsf{fma}\left(\frac{c}{b}, \frac{c \cdot a}{b}, c\right)\right)\right)}{b}
\end{array}
Initial program 29.7%
Taylor expanded in b around inf
Applied rewrites97.4%
Applied rewrites97.4%
Final simplification97.4%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (* (* c a) c)))
(/
(fma
(* (* -2.0 a) a)
(* (/ c (* b b)) (/ (* c c) (* b b)))
(fma
(- (* -5.0 (/ (* t_0 t_0) (pow b 6.0))) (* (/ c b) (/ c b)))
a
(- c)))
b)))
double code(double a, double b, double c) {
double t_0 = (c * a) * c;
return fma(((-2.0 * a) * a), ((c / (b * b)) * ((c * c) / (b * b))), fma(((-5.0 * ((t_0 * t_0) / pow(b, 6.0))) - ((c / b) * (c / b))), a, -c)) / b;
}
function code(a, b, c) t_0 = Float64(Float64(c * a) * c) return Float64(fma(Float64(Float64(-2.0 * a) * a), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), fma(Float64(Float64(-5.0 * Float64(Float64(t_0 * t_0) / (b ^ 6.0))) - Float64(Float64(c / b) * Float64(c / b))), a, Float64(-c))) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(c * a), $MachinePrecision] * c), $MachinePrecision]}, N[(N[(N[(N[(-2.0 * a), $MachinePrecision] * a), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(-5.0 * N[(N[(t$95$0 * t$95$0), $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[(c / b), $MachinePrecision] * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * a + (-c)), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(c \cdot a\right) \cdot c\\
\frac{\mathsf{fma}\left(\left(-2 \cdot a\right) \cdot a, \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(-5 \cdot \frac{t\_0 \cdot t\_0}{{b}^{6}} - \frac{c}{b} \cdot \frac{c}{b}, a, -c\right)\right)}{b}
\end{array}
\end{array}
Initial program 29.7%
Taylor expanded in b around inf
Applied rewrites97.4%
Applied rewrites97.4%
Taylor expanded in a around 0
Applied rewrites97.4%
Applied rewrites97.4%
Final simplification97.4%
(FPCore (a b c) :precision binary64 (/ (fma (fma (* (pow (/ a (* b b)) 2.0) c) -2.0 (/ a (* (- b) b))) (* c c) (- c)) b))
double code(double a, double b, double c) {
return fma(fma((pow((a / (b * b)), 2.0) * c), -2.0, (a / (-b * b))), (c * c), -c) / b;
}
function code(a, b, c) return Float64(fma(fma(Float64((Float64(a / Float64(b * b)) ^ 2.0) * c), -2.0, Float64(a / Float64(Float64(-b) * b))), Float64(c * c), Float64(-c)) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(N[Power[N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] * c), $MachinePrecision] * -2.0 + N[(a / N[((-b) * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(c * c), $MachinePrecision] + (-c)), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\mathsf{fma}\left({\left(\frac{a}{b \cdot b}\right)}^{2} \cdot c, -2, \frac{a}{\left(-b\right) \cdot b}\right), c \cdot c, -c\right)}{b}
\end{array}
Initial program 29.7%
Taylor expanded in b around inf
Applied rewrites97.4%
Taylor expanded in c around 0
Applied rewrites96.3%
Applied rewrites96.4%
Final simplification96.4%
(FPCore (a b c) :precision binary64 (/ (fma (* (* -2.0 a) a) (* (/ c (* b b)) (/ (* c c) (* b b))) (- (fma (/ (* c c) b) (/ a b) c))) b))
double code(double a, double b, double c) {
return fma(((-2.0 * a) * a), ((c / (b * b)) * ((c * c) / (b * b))), -fma(((c * c) / b), (a / b), c)) / b;
}
function code(a, b, c) return Float64(fma(Float64(Float64(-2.0 * a) * a), Float64(Float64(c / Float64(b * b)) * Float64(Float64(c * c) / Float64(b * b))), Float64(-fma(Float64(Float64(c * c) / b), Float64(a / b), c))) / b) end
code[a_, b_, c_] := N[(N[(N[(N[(-2.0 * a), $MachinePrecision] * a), $MachinePrecision] * N[(N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + (-N[(N[(N[(c * c), $MachinePrecision] / b), $MachinePrecision] * N[(a / b), $MachinePrecision] + c), $MachinePrecision])), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\left(-2 \cdot a\right) \cdot a, \frac{c}{b \cdot b} \cdot \frac{c \cdot c}{b \cdot b}, -\mathsf{fma}\left(\frac{c \cdot c}{b}, \frac{a}{b}, c\right)\right)}{b}
\end{array}
Initial program 29.7%
Taylor expanded in b around inf
Applied rewrites97.4%
Applied rewrites97.4%
Taylor expanded in b around inf
Applied rewrites96.4%
Final simplification96.4%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (/ c (* b b))))
(/
(fma
(* (* -2.0 a) a)
(* t_0 (/ (* c c) (* b b)))
(* (fma (- a) t_0 -1.0) c))
b)))
double code(double a, double b, double c) {
double t_0 = c / (b * b);
return fma(((-2.0 * a) * a), (t_0 * ((c * c) / (b * b))), (fma(-a, t_0, -1.0) * c)) / b;
}
function code(a, b, c) t_0 = Float64(c / Float64(b * b)) return Float64(fma(Float64(Float64(-2.0 * a) * a), Float64(t_0 * Float64(Float64(c * c) / Float64(b * b))), Float64(fma(Float64(-a), t_0, -1.0) * c)) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(-2.0 * a), $MachinePrecision] * a), $MachinePrecision] * N[(t$95$0 * N[(N[(c * c), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[((-a) * t$95$0 + -1.0), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{c}{b \cdot b}\\
\frac{\mathsf{fma}\left(\left(-2 \cdot a\right) \cdot a, t\_0 \cdot \frac{c \cdot c}{b \cdot b}, \mathsf{fma}\left(-a, t\_0, -1\right) \cdot c\right)}{b}
\end{array}
\end{array}
Initial program 29.7%
Taylor expanded in b around inf
Applied rewrites97.4%
Applied rewrites97.4%
Taylor expanded in c around 0
Applied rewrites96.3%
Final simplification96.3%
(FPCore (a b c)
:precision binary64
(/
(*
(fma
c
(- (/ (/ (* (* (* a a) c) -2.0) (* b b)) (* b b)) (/ a (* b b)))
-1.0)
c)
b))
double code(double a, double b, double c) {
return (fma(c, ((((((a * a) * c) * -2.0) / (b * b)) / (b * b)) - (a / (b * b))), -1.0) * c) / b;
}
function code(a, b, c) return Float64(Float64(fma(c, Float64(Float64(Float64(Float64(Float64(Float64(a * a) * c) * -2.0) / Float64(b * b)) / Float64(b * b)) - Float64(a / Float64(b * b))), -1.0) * c) / b) end
code[a_, b_, c_] := N[(N[(N[(c * N[(N[(N[(N[(N[(N[(a * a), $MachinePrecision] * c), $MachinePrecision] * -2.0), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] - N[(a / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision] * c), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(c, \frac{\frac{\left(\left(a \cdot a\right) \cdot c\right) \cdot -2}{b \cdot b}}{b \cdot b} - \frac{a}{b \cdot b}, -1\right) \cdot c}{b}
\end{array}
Initial program 29.7%
Taylor expanded in b around inf
Applied rewrites97.4%
Taylor expanded in c around 0
Applied rewrites96.3%
Applied rewrites96.3%
Final simplification96.3%
(FPCore (a b c) :precision binary64 (/ 0.5 (fma 0.5 (/ a b) (* (/ b c) -0.5))))
double code(double a, double b, double c) {
return 0.5 / fma(0.5, (a / b), ((b / c) * -0.5));
}
function code(a, b, c) return Float64(0.5 / fma(0.5, Float64(a / b), Float64(Float64(b / c) * -0.5))) end
code[a_, b_, c_] := N[(0.5 / N[(0.5 * N[(a / b), $MachinePrecision] + N[(N[(b / c), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{\mathsf{fma}\left(0.5, \frac{a}{b}, \frac{b}{c} \cdot -0.5\right)}
\end{array}
Initial program 29.7%
lift-/.f64N/A
clear-numN/A
lift-*.f64N/A
associate-/l*N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-/.f6429.7
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
lower--.f6429.7
Applied rewrites29.7%
Taylor expanded in a around 0
+-commutativeN/A
lower-fma.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-/.f6493.2
Applied rewrites93.2%
Final simplification93.2%
(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 29.7%
Taylor expanded in b around inf
Applied rewrites97.4%
Taylor expanded in c around 0
Applied rewrites96.3%
Taylor expanded in c around 0
Applied rewrites93.1%
(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 29.7%
Taylor expanded in c around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6483.0
Applied rewrites83.0%
(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 29.7%
lift-/.f64N/A
lift-+.f64N/A
+-commutativeN/A
lift-neg.f64N/A
unsub-negN/A
div-subN/A
lower--.f64N/A
Applied rewrites29.4%
lift--.f64N/A
sub-negN/A
+-commutativeN/A
lift-/.f64N/A
div-invN/A
distribute-lft-neg-inN/A
lower-fma.f64N/A
lower-neg.f64N/A
lift-*.f64N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f6430.6
lift-/.f64N/A
clear-numN/A
associate-/r/N/A
lower-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f6431.1
lift-fma.f64N/A
Applied rewrites31.1%
Taylor expanded in c around 0
distribute-rgt-outN/A
metadata-evalN/A
mul0-rgt3.2
Applied rewrites3.2%
herbie shell --seed 2024249
(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)))