
(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
(-
(-
(fma
-0.25
(* 20.0 (/ (pow c 4.0) (/ (pow b 7.0) (pow a 3.0))))
(/ (* (pow c 3.0) -2.0) (/ (pow b 5.0) (* a a))))
(/ c b))
(/ (* c (* c a)) (pow b 3.0))))
double code(double a, double b, double c) {
return (fma(-0.25, (20.0 * (pow(c, 4.0) / (pow(b, 7.0) / pow(a, 3.0)))), ((pow(c, 3.0) * -2.0) / (pow(b, 5.0) / (a * a)))) - (c / b)) - ((c * (c * a)) / pow(b, 3.0));
}
function code(a, b, c) return Float64(Float64(fma(-0.25, Float64(20.0 * Float64((c ^ 4.0) / Float64((b ^ 7.0) / (a ^ 3.0)))), Float64(Float64((c ^ 3.0) * -2.0) / Float64((b ^ 5.0) / Float64(a * a)))) - Float64(c / b)) - Float64(Float64(c * Float64(c * a)) / (b ^ 3.0))) end
code[a_, b_, c_] := N[(N[(N[(-0.25 * N[(20.0 * N[(N[Power[c, 4.0], $MachinePrecision] / N[(N[Power[b, 7.0], $MachinePrecision] / N[Power[a, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[Power[c, 3.0], $MachinePrecision] * -2.0), $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $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}
\\
\left(\mathsf{fma}\left(-0.25, 20 \cdot \frac{{c}^{4}}{\frac{{b}^{7}}{{a}^{3}}}, \frac{{c}^{3} \cdot -2}{\frac{{b}^{5}}{a \cdot a}}\right) - \frac{c}{b}\right) - \frac{c \cdot \left(c \cdot a\right)}{{b}^{3}}
\end{array}
Initial program 18.4%
neg-sub018.4%
associate-+l-18.4%
sub0-neg18.4%
neg-mul-118.4%
associate-*l/18.4%
*-commutative18.4%
associate-/r*18.4%
/-rgt-identity18.4%
metadata-eval18.4%
Simplified18.4%
Taylor expanded in a around 0 97.7%
Simplified97.7%
Taylor expanded in c around 0 97.7%
associate-/l*97.7%
Simplified97.7%
Final simplification97.7%
(FPCore (a b c) :precision binary64 (- (- (/ (* (pow c 3.0) -2.0) (/ (pow b 5.0) (* a a))) (/ c b)) (/ (* c (* c a)) (pow b 3.0))))
double code(double a, double b, double c) {
return (((pow(c, 3.0) * -2.0) / (pow(b, 5.0) / (a * a))) - (c / b)) - ((c * (c * a)) / 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 ** 3.0d0) * (-2.0d0)) / ((b ** 5.0d0) / (a * a))) - (c / b)) - ((c * (c * a)) / (b ** 3.0d0))
end function
public static double code(double a, double b, double c) {
return (((Math.pow(c, 3.0) * -2.0) / (Math.pow(b, 5.0) / (a * a))) - (c / b)) - ((c * (c * a)) / Math.pow(b, 3.0));
}
def code(a, b, c): return (((math.pow(c, 3.0) * -2.0) / (math.pow(b, 5.0) / (a * a))) - (c / b)) - ((c * (c * a)) / math.pow(b, 3.0))
function code(a, b, c) return Float64(Float64(Float64(Float64((c ^ 3.0) * -2.0) / Float64((b ^ 5.0) / Float64(a * a))) - Float64(c / b)) - Float64(Float64(c * Float64(c * a)) / (b ^ 3.0))) end
function tmp = code(a, b, c) tmp = ((((c ^ 3.0) * -2.0) / ((b ^ 5.0) / (a * a))) - (c / b)) - ((c * (c * a)) / (b ^ 3.0)); end
code[a_, b_, c_] := N[(N[(N[(N[(N[Power[c, 3.0], $MachinePrecision] * -2.0), $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $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}
\\
\left(\frac{{c}^{3} \cdot -2}{\frac{{b}^{5}}{a \cdot a}} - \frac{c}{b}\right) - \frac{c \cdot \left(c \cdot a\right)}{{b}^{3}}
\end{array}
Initial program 18.4%
neg-sub018.4%
associate-+l-18.4%
sub0-neg18.4%
neg-mul-118.4%
associate-*l/18.4%
*-commutative18.4%
associate-/r*18.4%
/-rgt-identity18.4%
metadata-eval18.4%
Simplified18.4%
Taylor expanded in b around inf 97.1%
+-commutative97.1%
mul-1-neg97.1%
unsub-neg97.1%
+-commutative97.1%
mul-1-neg97.1%
unsub-neg97.1%
*-commutative97.1%
associate-/l*97.1%
associate-*l/97.1%
unpow297.1%
Simplified97.1%
Final simplification97.1%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (/ (* c (* c a)) (pow b 3.0))))
double code(double a, double b, double c) {
return (-c / b) - ((c * (c * a)) / 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) - ((c * (c * a)) / (b ** 3.0d0))
end function
public static double code(double a, double b, double c) {
return (-c / b) - ((c * (c * a)) / Math.pow(b, 3.0));
}
def code(a, b, c): return (-c / b) - ((c * (c * a)) / math.pow(b, 3.0))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(Float64(c * Float64(c * a)) / (b ^ 3.0))) end
function tmp = code(a, b, c) tmp = (-c / b) - ((c * (c * a)) / (b ^ 3.0)); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(N[(c * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - \frac{c \cdot \left(c \cdot a\right)}{{b}^{3}}
\end{array}
Initial program 18.4%
neg-sub018.4%
associate-+l-18.4%
sub0-neg18.4%
neg-mul-118.4%
associate-*l/18.4%
*-commutative18.4%
associate-/r*18.4%
/-rgt-identity18.4%
metadata-eval18.4%
Simplified18.4%
Taylor expanded in b around inf 95.6%
+-commutative95.6%
mul-1-neg95.6%
unsub-neg95.6%
associate-*r/95.6%
neg-mul-195.6%
unpow295.6%
associate-*l*95.6%
Simplified95.6%
Final simplification95.6%
(FPCore (a b c) :precision binary64 (* (/ (* c (* 4.0 a)) (+ (+ b b) (* -2.0 (* a (/ c b))))) (/ -0.5 a)))
double code(double a, double b, double c) {
return ((c * (4.0 * a)) / ((b + b) + (-2.0 * (a * (c / b))))) * (-0.5 / 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 * (4.0d0 * a)) / ((b + b) + ((-2.0d0) * (a * (c / b))))) * ((-0.5d0) / a)
end function
public static double code(double a, double b, double c) {
return ((c * (4.0 * a)) / ((b + b) + (-2.0 * (a * (c / b))))) * (-0.5 / a);
}
def code(a, b, c): return ((c * (4.0 * a)) / ((b + b) + (-2.0 * (a * (c / b))))) * (-0.5 / a)
function code(a, b, c) return Float64(Float64(Float64(c * Float64(4.0 * a)) / Float64(Float64(b + b) + Float64(-2.0 * Float64(a * Float64(c / b))))) * Float64(-0.5 / a)) end
function tmp = code(a, b, c) tmp = ((c * (4.0 * a)) / ((b + b) + (-2.0 * (a * (c / b))))) * (-0.5 / a); end
code[a_, b_, c_] := N[(N[(N[(c * N[(4.0 * a), $MachinePrecision]), $MachinePrecision] / N[(N[(b + b), $MachinePrecision] + N[(-2.0 * N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-0.5 / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \left(4 \cdot a\right)}{\left(b + b\right) + -2 \cdot \left(a \cdot \frac{c}{b}\right)} \cdot \frac{-0.5}{a}
\end{array}
Initial program 18.4%
neg-sub018.4%
associate-+l-18.4%
sub0-neg18.4%
neg-mul-118.4%
associate-*l/18.4%
*-commutative18.4%
associate-/r*18.4%
/-rgt-identity18.4%
metadata-eval18.4%
Simplified18.4%
Taylor expanded in a around 0 13.8%
*-commutative13.8%
associate-/l*13.8%
Simplified13.8%
flip--13.7%
associate-/l*13.7%
*-commutative13.7%
associate-/l*13.7%
*-commutative13.7%
associate-/l*13.7%
*-commutative13.7%
Applied egg-rr13.7%
difference-of-squares13.8%
associate-+r+13.8%
associate-*l/13.8%
*-commutative13.8%
associate--r+89.4%
associate-*l/89.5%
*-commutative89.5%
associate-+r+89.5%
associate-*l/89.5%
*-commutative89.5%
Simplified89.5%
Taylor expanded in b around inf 95.2%
*-commutative95.2%
associate-*l*95.2%
Simplified95.2%
Final simplification95.2%
(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 18.4%
neg-sub018.4%
associate-+l-18.4%
sub0-neg18.4%
neg-mul-118.4%
associate-*l/18.4%
*-commutative18.4%
associate-/r*18.4%
/-rgt-identity18.4%
metadata-eval18.4%
Simplified18.4%
Taylor expanded in b around inf 89.9%
associate-*r/89.9%
neg-mul-189.9%
Simplified89.9%
Final simplification89.9%
herbie shell --seed 2023214
(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)))