
(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 b 5.0) (* a a)))
(/ (* -5.0 (/ (pow c 4.0) (/ (pow b 6.0) (pow a 3.0)))) b))
(/ c b))
(/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
return (fma(-2.0, (pow(c, 3.0) / (pow(b, 5.0) / (a * a))), ((-5.0 * (pow(c, 4.0) / (pow(b, 6.0) / pow(a, 3.0)))) / b)) - (c / b)) - ((c * c) / (pow(b, 3.0) / a));
}
function code(a, b, c) return Float64(Float64(fma(-2.0, Float64((c ^ 3.0) / Float64((b ^ 5.0) / Float64(a * a))), Float64(Float64(-5.0 * Float64((c ^ 4.0) / Float64((b ^ 6.0) / (a ^ 3.0)))) / b)) - Float64(c / b)) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
code[a_, b_, c_] := N[(N[(N[(-2.0 * N[(N[Power[c, 3.0], $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(-5.0 * N[(N[Power[c, 4.0], $MachinePrecision] / N[(N[Power[b, 6.0], $MachinePrecision] / N[Power[a, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $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(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{-5 \cdot \frac{{c}^{4}}{\frac{{b}^{6}}{{a}^{3}}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 20.6%
/-rgt-identity20.6%
metadata-eval20.6%
associate-/l*20.6%
associate-*r/20.6%
+-commutative20.6%
unsub-neg20.6%
fma-neg20.6%
associate-*l*20.6%
*-commutative20.6%
distribute-rgt-neg-in20.6%
metadata-eval20.6%
associate-/r*20.6%
metadata-eval20.6%
metadata-eval20.6%
Simplified20.6%
Taylor expanded in a around 0 97.9%
Simplified97.9%
Taylor expanded in c around 0 97.9%
associate-/l*97.9%
Simplified97.9%
Final simplification97.9%
(FPCore (a b c) :precision binary64 (- (- (/ (* (pow c 3.0) (* a (* -2.0 a))) (pow b 5.0)) (/ c b)) (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
return (((pow(c, 3.0) * (a * (-2.0 * a))) / 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 = ((((c ** 3.0d0) * (a * ((-2.0d0) * a))) / (b ** 5.0d0)) - (c / b)) - ((c * c) / ((b ** 3.0d0) / a))
end function
public static double code(double a, double b, double c) {
return (((Math.pow(c, 3.0) * (a * (-2.0 * a))) / Math.pow(b, 5.0)) - (c / b)) - ((c * c) / (Math.pow(b, 3.0) / a));
}
def code(a, b, c): return (((math.pow(c, 3.0) * (a * (-2.0 * a))) / math.pow(b, 5.0)) - (c / b)) - ((c * c) / (math.pow(b, 3.0) / a))
function code(a, b, c) return Float64(Float64(Float64(Float64((c ^ 3.0) * Float64(a * Float64(-2.0 * a))) / (b ^ 5.0)) - Float64(c / b)) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
function tmp = code(a, b, c) tmp = ((((c ^ 3.0) * (a * (-2.0 * a))) / (b ^ 5.0)) - (c / b)) - ((c * c) / ((b ^ 3.0) / a)); end
code[a_, b_, c_] := N[(N[(N[(N[(N[Power[c, 3.0], $MachinePrecision] * N[(a * N[(-2.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $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(\frac{{c}^{3} \cdot \left(a \cdot \left(-2 \cdot a\right)\right)}{{b}^{5}} - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 20.6%
/-rgt-identity20.6%
metadata-eval20.6%
associate-/l*20.6%
associate-*r/20.6%
+-commutative20.6%
unsub-neg20.6%
fma-neg20.6%
associate-*l*20.6%
*-commutative20.6%
distribute-rgt-neg-in20.6%
metadata-eval20.6%
associate-/r*20.6%
metadata-eval20.6%
metadata-eval20.6%
Simplified20.6%
Taylor expanded in b around inf 96.9%
+-commutative96.9%
mul-1-neg96.9%
unsub-neg96.9%
Simplified96.9%
Final simplification96.9%
(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 20.6%
/-rgt-identity20.6%
metadata-eval20.6%
associate-/l*20.6%
associate-*r/20.6%
+-commutative20.6%
unsub-neg20.6%
fma-neg20.6%
associate-*l*20.6%
*-commutative20.6%
distribute-rgt-neg-in20.6%
metadata-eval20.6%
associate-/r*20.6%
metadata-eval20.6%
metadata-eval20.6%
Simplified20.6%
Taylor expanded in b around inf 94.7%
+-commutative94.7%
mul-1-neg94.7%
unsub-neg94.7%
mul-1-neg94.7%
distribute-neg-frac94.7%
associate-/l*94.7%
unpow294.7%
Simplified94.7%
Final simplification94.7%
(FPCore (a b c) :precision binary64 (/ (/ (* a (* c -4.0)) (+ b (+ b (/ -2.0 (/ b (* c a)))))) (* a 2.0)))
double code(double a, double b, double c) {
return ((a * (c * -4.0)) / (b + (b + (-2.0 / (b / (c * a)))))) / (a * 2.0);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((a * (c * (-4.0d0))) / (b + (b + ((-2.0d0) / (b / (c * a)))))) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
return ((a * (c * -4.0)) / (b + (b + (-2.0 / (b / (c * a)))))) / (a * 2.0);
}
def code(a, b, c): return ((a * (c * -4.0)) / (b + (b + (-2.0 / (b / (c * a)))))) / (a * 2.0)
function code(a, b, c) return Float64(Float64(Float64(a * Float64(c * -4.0)) / Float64(b + Float64(b + Float64(-2.0 / Float64(b / Float64(c * a)))))) / Float64(a * 2.0)) end
function tmp = code(a, b, c) tmp = ((a * (c * -4.0)) / (b + (b + (-2.0 / (b / (c * a)))))) / (a * 2.0); end
code[a_, b_, c_] := N[(N[(N[(a * N[(c * -4.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[(b + N[(-2.0 / N[(b / N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{a \cdot \left(c \cdot -4\right)}{b + \left(b + \frac{-2}{\frac{b}{c \cdot a}}\right)}}{a \cdot 2}
\end{array}
Initial program 20.6%
*-commutative20.6%
+-commutative20.6%
unsub-neg20.6%
fma-neg20.6%
associate-*l*20.6%
*-commutative20.6%
distribute-rgt-neg-in20.6%
metadata-eval20.6%
Simplified20.6%
Taylor expanded in b around inf 14.9%
associate-*r/14.9%
Simplified14.9%
flip--14.9%
associate-/l*14.9%
*-commutative14.9%
associate-/l*14.9%
*-commutative14.9%
associate-/l*14.9%
*-commutative14.9%
Applied egg-rr14.9%
Taylor expanded in b around inf 94.4%
*-commutative94.4%
*-commutative94.4%
associate-*r*94.4%
Simplified94.4%
Final simplification94.4%
(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 20.6%
/-rgt-identity20.6%
metadata-eval20.6%
associate-/l*20.6%
associate-*r/20.6%
+-commutative20.6%
unsub-neg20.6%
fma-neg20.6%
associate-*l*20.6%
*-commutative20.6%
distribute-rgt-neg-in20.6%
metadata-eval20.6%
associate-/r*20.6%
metadata-eval20.6%
metadata-eval20.6%
Simplified20.6%
Taylor expanded in b around inf 88.6%
mul-1-neg88.6%
distribute-neg-frac88.6%
Simplified88.6%
Final simplification88.6%
herbie shell --seed 2023256
(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)))