
(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 (/ (pow c 4.0) (pow b 6.0))))
(-
(-
(fma
-0.25
(* (/ (fma 16.0 t_0 (* 4.0 t_0)) b) (pow a 3.0))
(* -2.0 (/ (* a a) (/ (pow b 5.0) (pow c 3.0)))))
(/ c b))
(/ (* c (* c a)) (pow b 3.0)))))
double code(double a, double b, double c) {
double t_0 = pow(c, 4.0) / pow(b, 6.0);
return (fma(-0.25, ((fma(16.0, t_0, (4.0 * t_0)) / b) * pow(a, 3.0)), (-2.0 * ((a * a) / (pow(b, 5.0) / pow(c, 3.0))))) - (c / b)) - ((c * (c * a)) / pow(b, 3.0));
}
function code(a, b, c) t_0 = Float64((c ^ 4.0) / (b ^ 6.0)) return Float64(Float64(fma(-0.25, Float64(Float64(fma(16.0, t_0, Float64(4.0 * t_0)) / b) * (a ^ 3.0)), Float64(-2.0 * Float64(Float64(a * a) / Float64((b ^ 5.0) / (c ^ 3.0))))) - Float64(c / b)) - Float64(Float64(c * Float64(c * a)) / (b ^ 3.0))) end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[Power[c, 4.0], $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(-0.25 * N[(N[(N[(16.0 * t$95$0 + N[(4.0 * t$95$0), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision] * N[Power[a, 3.0], $MachinePrecision]), $MachinePrecision] + N[(-2.0 * N[(N[(a * a), $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(N[(c * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{{c}^{4}}{{b}^{6}}\\
\left(\mathsf{fma}\left(-0.25, \frac{\mathsf{fma}\left(16, t_0, 4 \cdot t_0\right)}{b} \cdot {a}^{3}, -2 \cdot \frac{a \cdot a}{\frac{{b}^{5}}{{c}^{3}}}\right) - \frac{c}{b}\right) - \frac{c \cdot \left(c \cdot a\right)}{{b}^{3}}
\end{array}
\end{array}
Initial program 28.7%
neg-sub028.7%
associate-+l-28.7%
sub0-neg28.7%
neg-mul-128.7%
associate-*l/28.7%
*-commutative28.7%
associate-/r*28.7%
/-rgt-identity28.7%
metadata-eval28.7%
Simplified28.7%
Taylor expanded in a around 0 96.2%
+-commutative96.2%
mul-1-neg96.2%
unsub-neg96.2%
Simplified96.2%
Final simplification96.2%
(FPCore (a b c) :precision binary64 (- (fma -0.25 (* (/ (pow (* c a) 4.0) a) (/ 20.0 (pow b 7.0))) (- (* -2.0 (/ (* (* a a) (pow c 3.0)) (pow b 5.0))) (/ c b))) (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
return fma(-0.25, ((pow((c * a), 4.0) / a) * (20.0 / pow(b, 7.0))), ((-2.0 * (((a * a) * pow(c, 3.0)) / pow(b, 5.0))) - (c / b))) - ((c * c) / (pow(b, 3.0) / a));
}
function code(a, b, c) return Float64(fma(-0.25, Float64(Float64((Float64(c * a) ^ 4.0) / a) * Float64(20.0 / (b ^ 7.0))), Float64(Float64(-2.0 * Float64(Float64(Float64(a * a) * (c ^ 3.0)) / (b ^ 5.0))) - Float64(c / b))) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
code[a_, b_, c_] := N[(N[(-0.25 * N[(N[(N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision] / a), $MachinePrecision] * N[(20.0 / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-2.0 * N[(N[(N[(a * a), $MachinePrecision] * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.25, \frac{{\left(c \cdot a\right)}^{4}}{a} \cdot \frac{20}{{b}^{7}}, -2 \cdot \frac{\left(a \cdot a\right) \cdot {c}^{3}}{{b}^{5}} - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 28.7%
*-commutative28.7%
+-commutative28.7%
unsub-neg28.7%
fma-neg28.7%
associate-*l*28.7%
*-commutative28.7%
distribute-rgt-neg-in28.7%
metadata-eval28.7%
Simplified28.7%
fma-udef28.7%
*-commutative28.7%
Applied egg-rr28.7%
Taylor expanded in b around inf 96.2%
+-commutative96.2%
mul-1-neg96.2%
unsub-neg96.2%
Simplified96.2%
div-inv96.2%
distribute-rgt-out96.2%
pow-prod-down96.2%
metadata-eval96.2%
Applied egg-rr96.2%
associate-*r/96.2%
*-rgt-identity96.2%
times-frac96.2%
Simplified96.2%
Final simplification96.2%
(FPCore (a b c) :precision binary64 (- (- (* -2.0 (/ (* (* a a) (pow c 3.0)) (pow b 5.0))) (/ c b)) (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
return ((-2.0 * (((a * a) * pow(c, 3.0)) / pow(b, 5.0))) - (c / b)) - ((c * c) / (pow(b, 3.0) / a));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (((-2.0d0) * (((a * a) * (c ** 3.0d0)) / (b ** 5.0d0))) - (c / b)) - ((c * c) / ((b ** 3.0d0) / a))
end function
public static double code(double a, double b, double c) {
return ((-2.0 * (((a * a) * Math.pow(c, 3.0)) / Math.pow(b, 5.0))) - (c / b)) - ((c * c) / (Math.pow(b, 3.0) / a));
}
def code(a, b, c): return ((-2.0 * (((a * a) * math.pow(c, 3.0)) / math.pow(b, 5.0))) - (c / b)) - ((c * c) / (math.pow(b, 3.0) / a))
function code(a, b, c) return Float64(Float64(Float64(-2.0 * Float64(Float64(Float64(a * a) * (c ^ 3.0)) / (b ^ 5.0))) - Float64(c / b)) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
function tmp = code(a, b, c) tmp = ((-2.0 * (((a * a) * (c ^ 3.0)) / (b ^ 5.0))) - (c / b)) - ((c * c) / ((b ^ 3.0) / a)); end
code[a_, b_, c_] := N[(N[(N[(-2.0 * N[(N[(N[(a * a), $MachinePrecision] * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(-2 \cdot \frac{\left(a \cdot a\right) \cdot {c}^{3}}{{b}^{5}} - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 28.7%
*-commutative28.7%
+-commutative28.7%
unsub-neg28.7%
fma-neg28.7%
associate-*l*28.7%
*-commutative28.7%
distribute-rgt-neg-in28.7%
metadata-eval28.7%
Simplified28.7%
fma-udef28.7%
*-commutative28.7%
Applied egg-rr28.7%
Taylor expanded in b around inf 94.8%
+-commutative94.8%
mul-1-neg94.8%
unsub-neg94.8%
+-commutative94.8%
mul-1-neg94.8%
unsub-neg94.8%
*-commutative94.8%
unpow294.8%
associate-/l*94.8%
unpow294.8%
Simplified94.8%
Final simplification94.8%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
return (-c / b) - ((c * c) / (pow(b, 3.0) / a));
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (-c / b) - ((c * c) / ((b ** 3.0d0) / a))
end function
public static double code(double a, double b, double c) {
return (-c / b) - ((c * c) / (Math.pow(b, 3.0) / a));
}
def code(a, b, c): return (-c / b) - ((c * c) / (math.pow(b, 3.0) / a))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
function tmp = code(a, b, c) tmp = (-c / b) - ((c * c) / ((b ^ 3.0) / a)); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 28.7%
*-commutative28.7%
+-commutative28.7%
unsub-neg28.7%
fma-neg28.7%
associate-*l*28.7%
*-commutative28.7%
distribute-rgt-neg-in28.7%
metadata-eval28.7%
Simplified28.7%
fma-udef28.7%
*-commutative28.7%
Applied egg-rr28.7%
Taylor expanded in b around inf 92.1%
+-commutative92.1%
mul-1-neg92.1%
unsub-neg92.1%
associate-*r/92.1%
neg-mul-192.1%
associate-/l*92.1%
unpow292.1%
Simplified92.1%
Final simplification92.1%
(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 28.7%
neg-sub028.7%
associate-+l-28.7%
sub0-neg28.7%
neg-mul-128.7%
associate-*l/28.7%
*-commutative28.7%
associate-/r*28.7%
/-rgt-identity28.7%
metadata-eval28.7%
Simplified28.7%
Taylor expanded in b around inf 83.5%
associate-*r/83.5%
neg-mul-183.5%
Simplified83.5%
Final simplification83.5%
(FPCore (a b c) :precision binary64 (/ 0.0 a))
double code(double a, double b, double c) {
return 0.0 / a;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = 0.0d0 / a
end function
public static double code(double a, double b, double c) {
return 0.0 / a;
}
def code(a, b, c): return 0.0 / a
function code(a, b, c) return Float64(0.0 / a) end
function tmp = code(a, b, c) tmp = 0.0 / a; end
code[a_, b_, c_] := N[(0.0 / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{0}{a}
\end{array}
Initial program 28.7%
add-cbrt-cube28.7%
pow328.7%
neg-mul-128.7%
fma-def28.7%
*-commutative28.7%
*-commutative28.7%
*-commutative28.7%
Applied egg-rr28.7%
Taylor expanded in c around 0 3.2%
associate-*r/3.2%
distribute-rgt1-in3.2%
metadata-eval3.2%
mul0-lft3.2%
metadata-eval3.2%
Simplified3.2%
Final simplification3.2%
herbie shell --seed 2023181
(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)))