
(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 -2.0 (/ (* (pow c 3.0) (pow a 2.0)) (pow b 5.0)) (- (* -0.25 (/ (* 20.0 (pow (* c a) 4.0)) (* a (pow b 7.0)))) (fma a (/ (pow c 2.0) (pow b 3.0)) (/ c b)))))
double code(double a, double b, double c) {
return fma(-2.0, ((pow(c, 3.0) * pow(a, 2.0)) / pow(b, 5.0)), ((-0.25 * ((20.0 * pow((c * a), 4.0)) / (a * pow(b, 7.0)))) - fma(a, (pow(c, 2.0) / pow(b, 3.0)), (c / b))));
}
function code(a, b, c) return fma(-2.0, Float64(Float64((c ^ 3.0) * (a ^ 2.0)) / (b ^ 5.0)), Float64(Float64(-0.25 * Float64(Float64(20.0 * (Float64(c * a) ^ 4.0)) / Float64(a * (b ^ 7.0)))) - fma(a, Float64((c ^ 2.0) / (b ^ 3.0)), Float64(c / b)))) end
code[a_, b_, c_] := 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] + N[(N[(-0.25 * N[(N[(20.0 * N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision]), $MachinePrecision] / N[(a * N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(a * N[(N[Power[c, 2.0], $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision] + N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-2, \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}}, -0.25 \cdot \frac{20 \cdot {\left(c \cdot a\right)}^{4}}{a \cdot {b}^{7}} - \mathsf{fma}\left(a, \frac{{c}^{2}}{{b}^{3}}, \frac{c}{b}\right)\right)
\end{array}
Initial program 14.6%
*-commutative14.6%
Simplified14.6%
Taylor expanded in b around inf 97.5%
fma-define97.5%
*-commutative97.5%
associate-+r+97.5%
+-commutative97.5%
distribute-lft-out97.5%
mul-1-neg97.5%
Simplified97.5%
pow197.5%
associate-*r*97.5%
pow-prod-down97.5%
Applied egg-rr97.5%
unpow197.5%
*-commutative97.5%
Simplified97.5%
Final simplification97.5%
(FPCore (a b c) :precision binary64 (- (* -2.0 (/ (* (pow c 3.0) (pow a 2.0)) (pow b 5.0))) (+ (/ c b) (/ (* a (pow c 2.0)) (pow b 3.0)))))
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) + ((a * pow(c, 2.0)) / 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) * (((c ** 3.0d0) * (a ** 2.0d0)) / (b ** 5.0d0))) - ((c / b) + ((a * (c ** 2.0d0)) / (b ** 3.0d0)))
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) + ((a * Math.pow(c, 2.0)) / Math.pow(b, 3.0)));
}
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) + ((a * math.pow(c, 2.0)) / math.pow(b, 3.0)))
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(a * (c ^ 2.0)) / (b ^ 3.0)))) end
function tmp = code(a, b, c) tmp = (-2.0 * (((c ^ 3.0) * (a ^ 2.0)) / (b ^ 5.0))) - ((c / b) + ((a * (c ^ 2.0)) / (b ^ 3.0))); 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[(a * N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-2 \cdot \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}} - \left(\frac{c}{b} + \frac{a \cdot {c}^{2}}{{b}^{3}}\right)
\end{array}
Initial program 14.6%
*-commutative14.6%
Simplified14.6%
Taylor expanded in b around inf 96.8%
Final simplification96.8%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (/ (* a (pow c 2.0)) (pow b 3.0))))
double code(double a, double b, double c) {
return (-c / b) - ((a * pow(c, 2.0)) / 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 ** 2.0d0)) / (b ** 3.0d0))
end function
public static double code(double a, double b, double c) {
return (-c / b) - ((a * Math.pow(c, 2.0)) / Math.pow(b, 3.0));
}
def code(a, b, c): return (-c / b) - ((a * math.pow(c, 2.0)) / math.pow(b, 3.0))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(Float64(a * (c ^ 2.0)) / (b ^ 3.0))) end
function tmp = code(a, b, c) tmp = (-c / b) - ((a * (c ^ 2.0)) / (b ^ 3.0)); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(N[(a * N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}}
\end{array}
Initial program 14.6%
*-commutative14.6%
Simplified14.6%
Taylor expanded in b around inf 95.5%
distribute-lft-out95.5%
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 14.6%
*-commutative14.6%
Simplified14.6%
Taylor expanded in b around inf 92.3%
mul-1-neg92.3%
distribute-neg-frac292.3%
Simplified92.3%
Final simplification92.3%
(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 14.6%
*-commutative14.6%
Simplified14.6%
add-sqr-sqrt14.6%
difference-of-squares14.8%
associate-*l*14.8%
sqrt-prod14.8%
metadata-eval14.8%
associate-*l*14.8%
sqrt-prod14.8%
metadata-eval14.8%
Applied egg-rr14.8%
*-commutative14.8%
cancel-sign-sub-inv14.8%
metadata-eval14.8%
Simplified14.8%
Taylor expanded in b around inf 3.3%
associate-*r/3.3%
distribute-rgt-out3.3%
metadata-eval3.3%
mul0-rgt3.3%
metadata-eval3.3%
Simplified3.3%
Final simplification3.3%
herbie shell --seed 2024050
(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)))