
(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 5 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 (pow (* c a) 4.0)))
(fma
-2.0
(* (pow c 3.0) (/ (pow a 2.0) (pow b 5.0)))
(fma
-1.0
(fma a (* c (* c (pow b -3.0))) (/ c b))
(/ (* (fma 16.0 t_0 (* 4.0 t_0)) -0.25) (* a (pow b 7.0)))))))
double code(double a, double b, double c) {
double t_0 = pow((c * a), 4.0);
return fma(-2.0, (pow(c, 3.0) * (pow(a, 2.0) / pow(b, 5.0))), fma(-1.0, fma(a, (c * (c * pow(b, -3.0))), (c / b)), ((fma(16.0, t_0, (4.0 * t_0)) * -0.25) / (a * pow(b, 7.0)))));
}
function code(a, b, c) t_0 = Float64(c * a) ^ 4.0 return fma(-2.0, Float64((c ^ 3.0) * Float64((a ^ 2.0) / (b ^ 5.0))), fma(-1.0, fma(a, Float64(c * Float64(c * (b ^ -3.0))), Float64(c / b)), Float64(Float64(fma(16.0, t_0, Float64(4.0 * t_0)) * -0.25) / Float64(a * (b ^ 7.0))))) end
code[a_, b_, c_] := Block[{t$95$0 = N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision]}, N[(-2.0 * N[(N[Power[c, 3.0], $MachinePrecision] * N[(N[Power[a, 2.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.0 * N[(a * N[(c * N[(c * N[Power[b, -3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c / b), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(16.0 * t$95$0 + N[(4.0 * t$95$0), $MachinePrecision]), $MachinePrecision] * -0.25), $MachinePrecision] / N[(a * N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := {\left(c \cdot a\right)}^{4}\\
\mathsf{fma}\left(-2, {c}^{3} \cdot \frac{{a}^{2}}{{b}^{5}}, \mathsf{fma}\left(-1, \mathsf{fma}\left(a, c \cdot \left(c \cdot {b}^{-3}\right), \frac{c}{b}\right), \frac{\mathsf{fma}\left(16, t\_0, 4 \cdot t\_0\right) \cdot -0.25}{a \cdot {b}^{7}}\right)\right)
\end{array}
\end{array}
Initial program 14.4%
*-commutative14.4%
Simplified14.4%
Taylor expanded in b around inf 98.8%
Simplified98.8%
*-commutative98.8%
pow-prod-down98.8%
Applied egg-rr98.8%
*-commutative98.8%
pow-prod-down98.8%
Applied egg-rr98.8%
div-inv98.8%
unpow298.8%
associate-*l*98.8%
pow-flip98.8%
metadata-eval98.8%
Applied egg-rr98.8%
Final simplification98.8%
(FPCore (a b c) :precision binary64 (- (* -2.0 (/ (* (pow c 3.0) (pow a 2.0)) (pow b 5.0))) (+ (/ c b) (* (pow (/ c b) 2.0) (/ a b)))))
double code(double a, double b, double c) {
return (-2.0 * ((pow(c, 3.0) * pow(a, 2.0)) / pow(b, 5.0))) - ((c / b) + (pow((c / b), 2.0) * (a / b)));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((-2.0d0) * (((c ** 3.0d0) * (a ** 2.0d0)) / (b ** 5.0d0))) - ((c / b) + (((c / b) ** 2.0d0) * (a / b)))
end function
public static double code(double a, double b, double c) {
return (-2.0 * ((Math.pow(c, 3.0) * Math.pow(a, 2.0)) / Math.pow(b, 5.0))) - ((c / b) + (Math.pow((c / b), 2.0) * (a / b)));
}
def code(a, b, c): return (-2.0 * ((math.pow(c, 3.0) * math.pow(a, 2.0)) / math.pow(b, 5.0))) - ((c / b) + (math.pow((c / b), 2.0) * (a / b)))
function code(a, b, c) return Float64(Float64(-2.0 * Float64(Float64((c ^ 3.0) * (a ^ 2.0)) / (b ^ 5.0))) - Float64(Float64(c / b) + Float64((Float64(c / b) ^ 2.0) * Float64(a / b)))) end
function tmp = code(a, b, c) tmp = (-2.0 * (((c ^ 3.0) * (a ^ 2.0)) / (b ^ 5.0))) - ((c / b) + (((c / b) ^ 2.0) * (a / b))); end
code[a_, b_, c_] := N[(N[(-2.0 * N[(N[(N[Power[c, 3.0], $MachinePrecision] * N[Power[a, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[(c / b), $MachinePrecision] + N[(N[Power[N[(c / b), $MachinePrecision], 2.0], $MachinePrecision] * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-2 \cdot \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}} - \left(\frac{c}{b} + {\left(\frac{c}{b}\right)}^{2} \cdot \frac{a}{b}\right)
\end{array}
Initial program 14.4%
*-commutative14.4%
Simplified14.4%
Taylor expanded in b around inf 98.3%
*-commutative98.3%
unpow398.3%
times-frac98.3%
unpow298.3%
frac-times98.3%
pow298.3%
Applied egg-rr98.3%
Final simplification98.3%
(FPCore (a b c) :precision binary64 (/ (+ (* -4.0 (/ (pow (* c a) 3.0) (pow b 5.0))) (+ (* -2.0 (/ (* c a) b)) (* -2.0 (* (* c a) (* (pow b -3.0) (* c a)))))) (* a 2.0)))
double code(double a, double b, double c) {
return ((-4.0 * (pow((c * a), 3.0) / pow(b, 5.0))) + ((-2.0 * ((c * a) / b)) + (-2.0 * ((c * a) * (pow(b, -3.0) * (c * a)))))) / (a * 2.0);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (((-4.0d0) * (((c * a) ** 3.0d0) / (b ** 5.0d0))) + (((-2.0d0) * ((c * a) / b)) + ((-2.0d0) * ((c * a) * ((b ** (-3.0d0)) * (c * a)))))) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
return ((-4.0 * (Math.pow((c * a), 3.0) / Math.pow(b, 5.0))) + ((-2.0 * ((c * a) / b)) + (-2.0 * ((c * a) * (Math.pow(b, -3.0) * (c * a)))))) / (a * 2.0);
}
def code(a, b, c): return ((-4.0 * (math.pow((c * a), 3.0) / math.pow(b, 5.0))) + ((-2.0 * ((c * a) / b)) + (-2.0 * ((c * a) * (math.pow(b, -3.0) * (c * a)))))) / (a * 2.0)
function code(a, b, c) return Float64(Float64(Float64(-4.0 * Float64((Float64(c * a) ^ 3.0) / (b ^ 5.0))) + Float64(Float64(-2.0 * Float64(Float64(c * a) / b)) + Float64(-2.0 * Float64(Float64(c * a) * Float64((b ^ -3.0) * Float64(c * a)))))) / Float64(a * 2.0)) end
function tmp = code(a, b, c) tmp = ((-4.0 * (((c * a) ^ 3.0) / (b ^ 5.0))) + ((-2.0 * ((c * a) / b)) + (-2.0 * ((c * a) * ((b ^ -3.0) * (c * a)))))) / (a * 2.0); end
code[a_, b_, c_] := N[(N[(N[(-4.0 * N[(N[Power[N[(c * a), $MachinePrecision], 3.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-2.0 * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision] + N[(-2.0 * N[(N[(c * a), $MachinePrecision] * N[(N[Power[b, -3.0], $MachinePrecision] * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-4 \cdot \frac{{\left(c \cdot a\right)}^{3}}{{b}^{5}} + \left(-2 \cdot \frac{c \cdot a}{b} + -2 \cdot \left(\left(c \cdot a\right) \cdot \left({b}^{-3} \cdot \left(c \cdot a\right)\right)\right)\right)}{a \cdot 2}
\end{array}
Initial program 14.4%
*-commutative14.4%
Simplified14.4%
Taylor expanded in b around inf 97.8%
div-inv97.8%
add-sqr-sqrt97.8%
associate-*l*97.8%
*-commutative97.8%
sqrt-prod97.8%
unpow297.8%
sqrt-prod97.8%
add-sqr-sqrt97.8%
unpow297.8%
sqrt-prod97.8%
add-sqr-sqrt97.8%
*-commutative97.8%
sqrt-prod97.8%
unpow297.8%
sqrt-prod97.8%
add-sqr-sqrt97.8%
unpow297.8%
sqrt-prod97.8%
add-sqr-sqrt97.8%
pow-flip97.8%
metadata-eval97.8%
Applied egg-rr97.8%
*-commutative97.8%
pow-prod-down97.8%
Applied egg-rr97.8%
Final simplification97.8%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (* a (* c (* c (pow b -3.0))))))
double code(double a, double b, double c) {
return (-c / b) - (a * (c * (c * pow(b, -3.0))));
}
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) - (a * (c * (c * (b ** (-3.0d0)))))
end function
public static double code(double a, double b, double c) {
return (-c / b) - (a * (c * (c * Math.pow(b, -3.0))));
}
def code(a, b, c): return (-c / b) - (a * (c * (c * math.pow(b, -3.0))))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(a * Float64(c * Float64(c * (b ^ -3.0))))) end
function tmp = code(a, b, c) tmp = (-c / b) - (a * (c * (c * (b ^ -3.0)))); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(a * N[(c * N[(c * N[Power[b, -3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - a \cdot \left(c \cdot \left(c \cdot {b}^{-3}\right)\right)
\end{array}
Initial program 14.4%
*-commutative14.4%
Simplified14.4%
Taylor expanded in b around inf 96.7%
distribute-lft-out96.7%
associate-/l*96.7%
Simplified96.7%
div-inv98.8%
unpow298.8%
associate-*l*98.8%
pow-flip98.8%
metadata-eval98.8%
Applied egg-rr96.7%
Final simplification96.7%
(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(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 14.4%
*-commutative14.4%
Simplified14.4%
Taylor expanded in b around inf 92.8%
mul-1-neg92.8%
distribute-neg-frac292.8%
Simplified92.8%
Final simplification92.8%
herbie shell --seed 2024043
(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)))