
(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 7 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
(/ (pow a 3.0) (/ (pow b 7.0) (* (pow c 4.0) 20.0)))
(/ -2.0 (/ (pow b 5.0) (* a (* a (pow c 3.0))))))
(/ c b))
(/ a (/ (pow b 3.0) (* c c)))))
double code(double a, double b, double c) {
return (fma(-0.25, (pow(a, 3.0) / (pow(b, 7.0) / (pow(c, 4.0) * 20.0))), (-2.0 / (pow(b, 5.0) / (a * (a * pow(c, 3.0)))))) - (c / b)) - (a / (pow(b, 3.0) / (c * c)));
}
function code(a, b, c) return Float64(Float64(fma(-0.25, Float64((a ^ 3.0) / Float64((b ^ 7.0) / Float64((c ^ 4.0) * 20.0))), Float64(-2.0 / Float64((b ^ 5.0) / Float64(a * Float64(a * (c ^ 3.0)))))) - Float64(c / b)) - Float64(a / Float64((b ^ 3.0) / Float64(c * c)))) end
code[a_, b_, c_] := N[(N[(N[(-0.25 * N[(N[Power[a, 3.0], $MachinePrecision] / N[(N[Power[b, 7.0], $MachinePrecision] / N[(N[Power[c, 4.0], $MachinePrecision] * 20.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-2.0 / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * N[(a * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(a / N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\mathsf{fma}\left(-0.25, \frac{{a}^{3}}{\frac{{b}^{7}}{{c}^{4} \cdot 20}}, \frac{-2}{\frac{{b}^{5}}{a \cdot \left(a \cdot {c}^{3}\right)}}\right) - \frac{c}{b}\right) - \frac{a}{\frac{{b}^{3}}{c \cdot c}}
\end{array}
Initial program 18.3%
neg-sub018.3%
associate-+l-18.3%
sub0-neg18.3%
neg-mul-118.3%
associate-*l/18.3%
*-commutative18.3%
associate-/r*18.3%
/-rgt-identity18.3%
metadata-eval18.3%
Simplified18.3%
Taylor expanded in a around 0 97.0%
Simplified97.0%
Taylor expanded in b around 0 97.0%
associate-/l*97.0%
distribute-rgt-out97.0%
metadata-eval97.0%
Simplified97.0%
Final simplification97.0%
(FPCore (a b c) :precision binary64 (- (fma -5.0 (/ (pow c 4.0) (/ (pow b 7.0) (pow a 3.0))) (- (/ (* -2.0 (pow c 3.0)) (/ (pow b 5.0) (* a a))) (/ c b))) (* a (* c (/ c (pow b 3.0))))))
double code(double a, double b, double c) {
return fma(-5.0, (pow(c, 4.0) / (pow(b, 7.0) / pow(a, 3.0))), (((-2.0 * pow(c, 3.0)) / (pow(b, 5.0) / (a * a))) - (c / b))) - (a * (c * (c / pow(b, 3.0))));
}
function code(a, b, c) return Float64(fma(-5.0, Float64((c ^ 4.0) / Float64((b ^ 7.0) / (a ^ 3.0))), Float64(Float64(Float64(-2.0 * (c ^ 3.0)) / Float64((b ^ 5.0) / Float64(a * a))) - Float64(c / b))) - Float64(a * Float64(c * Float64(c / (b ^ 3.0))))) end
code[a_, b_, c_] := N[(N[(-5.0 * N[(N[Power[c, 4.0], $MachinePrecision] / N[(N[Power[b, 7.0], $MachinePrecision] / N[Power[a, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(-2.0 * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(a * N[(c * N[(c / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-5, \frac{{c}^{4}}{\frac{{b}^{7}}{{a}^{3}}}, \frac{-2 \cdot {c}^{3}}{\frac{{b}^{5}}{a \cdot a}} - \frac{c}{b}\right) - a \cdot \left(c \cdot \frac{c}{{b}^{3}}\right)
\end{array}
Initial program 18.3%
/-rgt-identity18.3%
metadata-eval18.3%
associate-/l*18.3%
associate-*r/18.3%
+-commutative18.3%
unsub-neg18.3%
fma-neg18.3%
associate-*l*18.3%
*-commutative18.3%
distribute-rgt-neg-in18.3%
metadata-eval18.3%
associate-/r*18.3%
metadata-eval18.3%
metadata-eval18.3%
Simplified18.3%
fma-udef18.3%
*-commutative18.3%
Applied egg-rr18.3%
Taylor expanded in a around 0 96.4%
Simplified96.6%
Taylor expanded in a around 0 97.0%
+-commutative97.0%
mul-1-neg97.0%
unsub-neg97.0%
Simplified97.0%
Final simplification97.0%
(FPCore (a b c)
:precision binary64
(*
(+
(fma
-0.5
(* (/ (pow a 4.0) b) (/ (* (pow c 4.0) 20.0) (pow b 6.0)))
(* -4.0 (/ (* (* a c) (* (* a c) (* a c))) (pow b 5.0))))
(* -2.0 (* a (+ (/ c b) (* a (/ (* c c) (pow b 3.0)))))))
(/ 0.5 a)))
double code(double a, double b, double c) {
return (fma(-0.5, ((pow(a, 4.0) / b) * ((pow(c, 4.0) * 20.0) / pow(b, 6.0))), (-4.0 * (((a * c) * ((a * c) * (a * c))) / pow(b, 5.0)))) + (-2.0 * (a * ((c / b) + (a * ((c * c) / pow(b, 3.0))))))) * (0.5 / a);
}
function code(a, b, c) return Float64(Float64(fma(-0.5, Float64(Float64((a ^ 4.0) / b) * Float64(Float64((c ^ 4.0) * 20.0) / (b ^ 6.0))), Float64(-4.0 * Float64(Float64(Float64(a * c) * Float64(Float64(a * c) * Float64(a * c))) / (b ^ 5.0)))) + Float64(-2.0 * Float64(a * Float64(Float64(c / b) + Float64(a * Float64(Float64(c * c) / (b ^ 3.0))))))) * Float64(0.5 / a)) end
code[a_, b_, c_] := N[(N[(N[(-0.5 * N[(N[(N[Power[a, 4.0], $MachinePrecision] / b), $MachinePrecision] * N[(N[(N[Power[c, 4.0], $MachinePrecision] * 20.0), $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-4.0 * N[(N[(N[(a * c), $MachinePrecision] * N[(N[(a * c), $MachinePrecision] * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-2.0 * N[(a * N[(N[(c / b), $MachinePrecision] + N[(a * N[(N[(c * c), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(0.5 / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\mathsf{fma}\left(-0.5, \frac{{a}^{4}}{b} \cdot \frac{{c}^{4} \cdot 20}{{b}^{6}}, -4 \cdot \frac{\left(a \cdot c\right) \cdot \left(\left(a \cdot c\right) \cdot \left(a \cdot c\right)\right)}{{b}^{5}}\right) + -2 \cdot \left(a \cdot \left(\frac{c}{b} + a \cdot \frac{c \cdot c}{{b}^{3}}\right)\right)\right) \cdot \frac{0.5}{a}
\end{array}
Initial program 18.3%
/-rgt-identity18.3%
metadata-eval18.3%
associate-/l*18.3%
associate-*r/18.3%
+-commutative18.3%
unsub-neg18.3%
fma-neg18.3%
associate-*l*18.3%
*-commutative18.3%
distribute-rgt-neg-in18.3%
metadata-eval18.3%
associate-/r*18.3%
metadata-eval18.3%
metadata-eval18.3%
Simplified18.3%
fma-udef18.3%
*-commutative18.3%
Applied egg-rr18.3%
Taylor expanded in a around 0 96.4%
Simplified96.6%
unpow396.6%
Applied egg-rr96.6%
Final simplification96.6%
(FPCore (a b c) :precision binary64 (- (- (/ -2.0 (/ (pow b 5.0) (* a (* a (pow c 3.0))))) (/ c b)) (/ a (/ (pow b 3.0) (* c c)))))
double code(double a, double b, double c) {
return ((-2.0 / (pow(b, 5.0) / (a * (a * pow(c, 3.0))))) - (c / b)) - (a / (pow(b, 3.0) / (c * c)));
}
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) / ((b ** 5.0d0) / (a * (a * (c ** 3.0d0))))) - (c / b)) - (a / ((b ** 3.0d0) / (c * c)))
end function
public static double code(double a, double b, double c) {
return ((-2.0 / (Math.pow(b, 5.0) / (a * (a * Math.pow(c, 3.0))))) - (c / b)) - (a / (Math.pow(b, 3.0) / (c * c)));
}
def code(a, b, c): return ((-2.0 / (math.pow(b, 5.0) / (a * (a * math.pow(c, 3.0))))) - (c / b)) - (a / (math.pow(b, 3.0) / (c * c)))
function code(a, b, c) return Float64(Float64(Float64(-2.0 / Float64((b ^ 5.0) / Float64(a * Float64(a * (c ^ 3.0))))) - Float64(c / b)) - Float64(a / Float64((b ^ 3.0) / Float64(c * c)))) end
function tmp = code(a, b, c) tmp = ((-2.0 / ((b ^ 5.0) / (a * (a * (c ^ 3.0))))) - (c / b)) - (a / ((b ^ 3.0) / (c * c))); end
code[a_, b_, c_] := N[(N[(N[(-2.0 / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * N[(a * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(a / N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{-2}{\frac{{b}^{5}}{a \cdot \left(a \cdot {c}^{3}\right)}} - \frac{c}{b}\right) - \frac{a}{\frac{{b}^{3}}{c \cdot c}}
\end{array}
Initial program 18.3%
neg-sub018.3%
associate-+l-18.3%
sub0-neg18.3%
neg-mul-118.3%
associate-*l/18.3%
*-commutative18.3%
associate-/r*18.3%
/-rgt-identity18.3%
metadata-eval18.3%
Simplified18.3%
Taylor expanded in b around inf 96.0%
+-commutative96.0%
mul-1-neg96.0%
unsub-neg96.0%
+-commutative96.0%
mul-1-neg96.0%
unsub-neg96.0%
associate-*r/96.0%
associate-/l*96.0%
*-commutative96.0%
unpow296.0%
associate-*l*96.0%
*-commutative96.0%
Simplified96.0%
Final simplification96.0%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (/ a (/ (pow b 3.0) (* c c)))))
double code(double a, double b, double c) {
return (-c / b) - (a / (pow(b, 3.0) / (c * c)));
}
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 / ((b ** 3.0d0) / (c * c)))
end function
public static double code(double a, double b, double c) {
return (-c / b) - (a / (Math.pow(b, 3.0) / (c * c)));
}
def code(a, b, c): return (-c / b) - (a / (math.pow(b, 3.0) / (c * c)))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(a / Float64((b ^ 3.0) / Float64(c * c)))) end
function tmp = code(a, b, c) tmp = (-c / b) - (a / ((b ^ 3.0) / (c * c))); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(a / N[(N[Power[b, 3.0], $MachinePrecision] / N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - \frac{a}{\frac{{b}^{3}}{c \cdot c}}
\end{array}
Initial program 18.3%
neg-sub018.3%
associate-+l-18.3%
sub0-neg18.3%
neg-mul-118.3%
associate-*l/18.3%
*-commutative18.3%
associate-/r*18.3%
/-rgt-identity18.3%
metadata-eval18.3%
Simplified18.3%
Taylor expanded in b around inf 94.5%
+-commutative94.5%
mul-1-neg94.5%
unsub-neg94.5%
associate-*r/94.5%
neg-mul-194.5%
*-commutative94.5%
associate-/l*94.5%
unpow294.5%
Simplified94.5%
Final simplification94.5%
(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 18.3%
neg-sub018.3%
associate-+l-18.3%
sub0-neg18.3%
neg-mul-118.3%
associate-*l/18.3%
*-commutative18.3%
associate-/r*18.3%
/-rgt-identity18.3%
metadata-eval18.3%
Simplified18.3%
Taylor expanded in b around inf 94.0%
distribute-lft-out94.0%
associate-/l*94.1%
associate-/l*94.1%
unpow294.1%
unpow294.1%
Simplified94.1%
Taylor expanded in c around 0 94.5%
+-commutative94.5%
mul-1-neg94.5%
unsub-neg94.5%
associate-*r/94.5%
neg-mul-194.5%
associate-/l*94.5%
unpow294.5%
Simplified94.5%
Final simplification94.5%
(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 18.3%
neg-sub018.3%
associate-+l-18.3%
sub0-neg18.3%
neg-mul-118.3%
associate-*l/18.3%
*-commutative18.3%
associate-/r*18.3%
/-rgt-identity18.3%
metadata-eval18.3%
Simplified18.3%
Taylor expanded in b around inf 90.1%
associate-*r/90.1%
neg-mul-190.1%
Simplified90.1%
Final simplification90.1%
herbie shell --seed 2023185
(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)))