
(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
(let* ((t_0 (* b (* b (* b b)))) (t_1 (* c (* c c))))
(/
(-
(-
(fma
(* -5.0 (* c t_1))
(/ (* a (* a a)) (* (* b b) t_0))
(/ (* (* a a) (* t_1 -2.0)) t_0))
(/ (* c (* c a)) (* b b)))
c)
b)))
double code(double a, double b, double c) {
double t_0 = b * (b * (b * b));
double t_1 = c * (c * c);
return ((fma((-5.0 * (c * t_1)), ((a * (a * a)) / ((b * b) * t_0)), (((a * a) * (t_1 * -2.0)) / t_0)) - ((c * (c * a)) / (b * b))) - c) / b;
}
function code(a, b, c) t_0 = Float64(b * Float64(b * Float64(b * b))) t_1 = Float64(c * Float64(c * c)) return Float64(Float64(Float64(fma(Float64(-5.0 * Float64(c * t_1)), Float64(Float64(a * Float64(a * a)) / Float64(Float64(b * b) * t_0)), Float64(Float64(Float64(a * a) * Float64(t_1 * -2.0)) / t_0)) - Float64(Float64(c * Float64(c * a)) / Float64(b * b))) - c) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(N[(-5.0 * N[(c * t$95$1), $MachinePrecision]), $MachinePrecision] * N[(N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(a * a), $MachinePrecision] * N[(t$95$1 * -2.0), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] - N[(N[(c * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - c), $MachinePrecision] / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot \left(b \cdot b\right)\right)\\
t_1 := c \cdot \left(c \cdot c\right)\\
\frac{\left(\mathsf{fma}\left(-5 \cdot \left(c \cdot t\_1\right), \frac{a \cdot \left(a \cdot a\right)}{\left(b \cdot b\right) \cdot t\_0}, \frac{\left(a \cdot a\right) \cdot \left(t\_1 \cdot -2\right)}{t\_0}\right) - \frac{c \cdot \left(c \cdot a\right)}{b \cdot b}\right) - c}{b}
\end{array}
\end{array}
Initial program 31.5%
Taylor expanded in a around 0
Simplified94.9%
Taylor expanded in b around inf
/-lowering-/.f64N/A
Simplified94.9%
Applied egg-rr95.0%
Final simplification95.0%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (* b (* b (* b b)))) (t_1 (* c (* c c))))
(/
(-
(fma
(* -5.0 (* c t_1))
(/ (* a (* a a)) (* (* b b) t_0))
(/ (* (* a a) (* t_1 -2.0)) t_0))
(fma (* c a) (/ c (* b b)) c))
b)))
double code(double a, double b, double c) {
double t_0 = b * (b * (b * b));
double t_1 = c * (c * c);
return (fma((-5.0 * (c * t_1)), ((a * (a * a)) / ((b * b) * t_0)), (((a * a) * (t_1 * -2.0)) / t_0)) - fma((c * a), (c / (b * b)), c)) / b;
}
function code(a, b, c) t_0 = Float64(b * Float64(b * Float64(b * b))) t_1 = Float64(c * Float64(c * c)) return Float64(Float64(fma(Float64(-5.0 * Float64(c * t_1)), Float64(Float64(a * Float64(a * a)) / Float64(Float64(b * b) * t_0)), Float64(Float64(Float64(a * a) * Float64(t_1 * -2.0)) / t_0)) - fma(Float64(c * a), Float64(c / Float64(b * b)), c)) / b) end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(-5.0 * N[(c * t$95$1), $MachinePrecision]), $MachinePrecision] * N[(N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision] / N[(N[(b * b), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(a * a), $MachinePrecision] * N[(t$95$1 * -2.0), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision] - N[(N[(c * a), $MachinePrecision] * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision] + c), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot \left(b \cdot b\right)\right)\\
t_1 := c \cdot \left(c \cdot c\right)\\
\frac{\mathsf{fma}\left(-5 \cdot \left(c \cdot t\_1\right), \frac{a \cdot \left(a \cdot a\right)}{\left(b \cdot b\right) \cdot t\_0}, \frac{\left(a \cdot a\right) \cdot \left(t\_1 \cdot -2\right)}{t\_0}\right) - \mathsf{fma}\left(c \cdot a, \frac{c}{b \cdot b}, c\right)}{b}
\end{array}
\end{array}
Initial program 31.5%
Taylor expanded in a around 0
Simplified94.9%
Taylor expanded in b around inf
/-lowering-/.f64N/A
Simplified94.9%
Applied egg-rr94.9%
Final simplification94.9%
(FPCore (a b c) :precision binary64 (/ (- (/ (- (/ (* (* c (* c c)) (* (* a a) -2.0)) (* b b)) (* (* c c) a)) (* b b)) c) b))
double code(double a, double b, double c) {
return ((((((c * (c * c)) * ((a * a) * -2.0)) / (b * b)) - ((c * c) * a)) / (b * b)) - 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 * (c * c)) * ((a * a) * (-2.0d0))) / (b * b)) - ((c * c) * a)) / (b * b)) - c) / b
end function
public static double code(double a, double b, double c) {
return ((((((c * (c * c)) * ((a * a) * -2.0)) / (b * b)) - ((c * c) * a)) / (b * b)) - c) / b;
}
def code(a, b, c): return ((((((c * (c * c)) * ((a * a) * -2.0)) / (b * b)) - ((c * c) * a)) / (b * b)) - c) / b
function code(a, b, c) return Float64(Float64(Float64(Float64(Float64(Float64(Float64(c * Float64(c * c)) * Float64(Float64(a * a) * -2.0)) / Float64(b * b)) - Float64(Float64(c * c) * a)) / Float64(b * b)) - c) / b) end
function tmp = code(a, b, c) tmp = ((((((c * (c * c)) * ((a * a) * -2.0)) / (b * b)) - ((c * c) * a)) / (b * b)) - c) / b; end
code[a_, b_, c_] := N[(N[(N[(N[(N[(N[(N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision] * N[(N[(a * a), $MachinePrecision] * -2.0), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] - c), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\frac{\left(c \cdot \left(c \cdot c\right)\right) \cdot \left(\left(a \cdot a\right) \cdot -2\right)}{b \cdot b} - \left(c \cdot c\right) \cdot a}{b \cdot b} - c}{b}
\end{array}
Initial program 31.5%
Taylor expanded in a around 0
Simplified94.9%
Taylor expanded in b around inf
/-lowering-/.f64N/A
Simplified94.9%
Applied egg-rr95.0%
Taylor expanded in b around inf
/-lowering-/.f64N/A
Simplified93.5%
Final simplification93.5%
(FPCore (a b c) :precision binary64 (- (fma a (/ (* c c) (* b (* b b))) (/ c b))))
double code(double a, double b, double c) {
return -fma(a, ((c * c) / (b * (b * b))), (c / b));
}
function code(a, b, c) return Float64(-fma(a, Float64(Float64(c * c) / Float64(b * Float64(b * b))), Float64(c / b))) end
code[a_, b_, c_] := (-N[(a * N[(N[(c * c), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c / b), $MachinePrecision]), $MachinePrecision])
\begin{array}{l}
\\
-\mathsf{fma}\left(a, \frac{c \cdot c}{b \cdot \left(b \cdot b\right)}, \frac{c}{b}\right)
\end{array}
Initial program 31.5%
Taylor expanded in a around 0
Simplified94.9%
Taylor expanded in a around 0
sub-negN/A
mul-1-negN/A
distribute-neg-outN/A
neg-lowering-neg.f64N/A
associate-/l*N/A
accelerator-lowering-fma.f64N/A
/-lowering-/.f64N/A
unpow2N/A
*-lowering-*.f64N/A
cube-multN/A
unpow2N/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f64N/A
/-lowering-/.f6490.7
Simplified90.7%
(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 31.5%
Taylor expanded in b around inf
distribute-lft-outN/A
associate-/l*N/A
mul-1-negN/A
neg-lowering-neg.f64N/A
/-lowering-/.f64N/A
+-commutativeN/A
*-commutativeN/A
associate-/l*N/A
accelerator-lowering-fma.f64N/A
unpow2N/A
*-lowering-*.f64N/A
/-lowering-/.f64N/A
unpow2N/A
*-lowering-*.f6490.7
Simplified90.7%
Final simplification90.7%
(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 31.5%
Taylor expanded in b around inf
mul-1-negN/A
distribute-neg-frac2N/A
/-lowering-/.f64N/A
neg-lowering-neg.f6481.4
Simplified81.4%
herbie shell --seed 2024204
(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)))