
(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))))
(/ -2.0 (/ (pow b 5.0) (* a (* a (pow c 3.0))))))
(/ 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)))), (-2.0 / (pow(b, 5.0) / (a * (a * pow(c, 3.0)))))) - (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(-2.0 / Float64((b ^ 5.0) / Float64(a * Float64(a * (c ^ 3.0)))))) - 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[(-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[(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{-2}{\frac{{b}^{5}}{a \cdot \left(a \cdot {c}^{3}\right)}}\right) - \frac{c}{b}\right) - \frac{c \cdot \left(c \cdot a\right)}{{b}^{3}}
\end{array}
Initial program 17.0%
neg-sub017.0%
associate-+l-17.0%
sub0-neg17.0%
neg-mul-117.0%
associate-*l/17.0%
*-commutative17.0%
associate-/r*17.0%
/-rgt-identity17.0%
metadata-eval17.0%
Simplified17.0%
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 (- (- (/ -2.0 (/ (pow b 5.0) (* a (* a (pow c 3.0))))) (/ c b)) (/ (* c (* c a)) (pow b 3.0))))
double code(double a, double b, double c) {
return ((-2.0 / (pow(b, 5.0) / (a * (a * pow(c, 3.0))))) - (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 = (((-2.0d0) / ((b ** 5.0d0) / (a * (a * (c ** 3.0d0))))) - (c / b)) - ((c * (c * a)) / (b ** 3.0d0))
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)) - ((c * (c * a)) / Math.pow(b, 3.0));
}
def code(a, b, c): return ((-2.0 / (math.pow(b, 5.0) / (a * (a * math.pow(c, 3.0))))) - (c / b)) - ((c * (c * a)) / math.pow(b, 3.0))
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(Float64(c * Float64(c * a)) / (b ^ 3.0))) end
function tmp = code(a, b, c) tmp = ((-2.0 / ((b ^ 5.0) / (a * (a * (c ^ 3.0))))) - (c / b)) - ((c * (c * a)) / (b ^ 3.0)); 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[(N[(c * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $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{c \cdot \left(c \cdot a\right)}{{b}^{3}}
\end{array}
Initial program 17.0%
neg-sub017.0%
associate-+l-17.0%
sub0-neg17.0%
neg-mul-117.0%
associate-*l/17.0%
*-commutative17.0%
associate-/r*17.0%
/-rgt-identity17.0%
metadata-eval17.0%
Simplified17.0%
Taylor expanded in b around inf 97.0%
+-commutative97.0%
mul-1-neg97.0%
unsub-neg97.0%
+-commutative97.0%
mul-1-neg97.0%
unsub-neg97.0%
associate-*r/97.0%
associate-/l*97.0%
*-commutative97.0%
unpow297.0%
associate-*l*97.0%
Simplified97.0%
Final simplification97.0%
(FPCore (a b c) :precision binary64 (- (/ (* (* c a) (- c)) (pow b 3.0)) (/ c b)))
double code(double a, double b, double c) {
return (((c * a) * -c) / pow(b, 3.0)) - (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 * a) * -c) / (b ** 3.0d0)) - (c / b)
end function
public static double code(double a, double b, double c) {
return (((c * a) * -c) / Math.pow(b, 3.0)) - (c / b);
}
def code(a, b, c): return (((c * a) * -c) / math.pow(b, 3.0)) - (c / b)
function code(a, b, c) return Float64(Float64(Float64(Float64(c * a) * Float64(-c)) / (b ^ 3.0)) - Float64(c / b)) end
function tmp = code(a, b, c) tmp = (((c * a) * -c) / (b ^ 3.0)) - (c / b); end
code[a_, b_, c_] := N[(N[(N[(N[(c * a), $MachinePrecision] * (-c)), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(c \cdot a\right) \cdot \left(-c\right)}{{b}^{3}} - \frac{c}{b}
\end{array}
Initial program 17.0%
neg-sub017.0%
associate-+l-17.0%
sub0-neg17.0%
neg-mul-117.0%
associate-*l/17.0%
*-commutative17.0%
associate-/r*17.0%
/-rgt-identity17.0%
metadata-eval17.0%
Simplified17.0%
Taylor expanded in b around inf 95.5%
distribute-lft-out95.5%
mul-1-neg95.5%
+-commutative95.5%
unpow295.5%
associate-*l*95.5%
Simplified95.5%
Final simplification95.5%
(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 17.0%
neg-sub017.0%
associate-+l-17.0%
sub0-neg17.0%
neg-mul-117.0%
associate-*l/17.0%
*-commutative17.0%
associate-/r*17.0%
/-rgt-identity17.0%
metadata-eval17.0%
Simplified17.0%
Taylor expanded in b around inf 90.6%
associate-*r/90.6%
neg-mul-190.6%
Simplified90.6%
Final simplification90.6%
(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 17.0%
add-log-exp8.6%
neg-mul-18.6%
fma-def8.6%
*-commutative8.6%
*-commutative8.6%
*-commutative8.6%
Applied egg-rr8.6%
Taylor expanded in c around 0 3.3%
associate-*r/3.3%
distribute-rgt1-in3.3%
metadata-eval3.3%
mul0-lft3.3%
metadata-eval3.3%
Simplified3.3%
Final simplification3.3%
herbie shell --seed 2023207
(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)))