
(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 6 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 a 3.0)) (pow b 7.0))))
(/ c b))
(* a (/ c (/ (pow b 3.0) c)))))
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(a, 3.0)) / pow(b, 7.0)))) - (c / b)) - (a * (c / (pow(b, 3.0) / c)));
}
function code(a, b, c) return Float64(Float64(fma(-2.0, Float64(Float64((c ^ 3.0) / (b ^ 5.0)) * Float64(a * a)), Float64(-5.0 * Float64(Float64((c ^ 4.0) * (a ^ 3.0)) / (b ^ 7.0)))) - Float64(c / b)) - Float64(a * Float64(c / Float64((b ^ 3.0) / c)))) end
code[a_, b_, c_] := N[(N[(N[(-2.0 * N[(N[(N[Power[c, 3.0], $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] * N[(a * a), $MachinePrecision]), $MachinePrecision] + N[(-5.0 * N[(N[(N[Power[c, 4.0], $MachinePrecision] * N[Power[a, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(a * N[(c / N[(N[Power[b, 3.0], $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{{b}^{5}} \cdot \left(a \cdot a\right), -5 \cdot \frac{{c}^{4} \cdot {a}^{3}}{{b}^{7}}\right) - \frac{c}{b}\right) - a \cdot \frac{c}{\frac{{b}^{3}}{c}}
\end{array}
Initial program 15.1%
Taylor expanded in a around 0 98.3%
+-commutative98.3%
mul-1-neg98.3%
unsub-neg98.3%
Simplified98.3%
Taylor expanded in c around 0 98.3%
Final simplification98.3%
(FPCore (a b c) :precision binary64 (- (fma -0.25 (* (/ (pow (* c a) 4.0) a) (/ 20.0 (pow b 7.0))) (- (/ (* -2.0 (pow c 3.0)) (/ (pow b 5.0) (* a a))) (/ c b))) (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
return fma(-0.25, ((pow((c * a), 4.0) / a) * (20.0 / pow(b, 7.0))), (((-2.0 * pow(c, 3.0)) / (pow(b, 5.0) / (a * a))) - (c / b))) - ((c * c) / (pow(b, 3.0) / a));
}
function code(a, b, c) return Float64(fma(-0.25, Float64(Float64((Float64(c * a) ^ 4.0) / a) * Float64(20.0 / (b ^ 7.0))), Float64(Float64(Float64(-2.0 * (c ^ 3.0)) / Float64((b ^ 5.0) / Float64(a * a))) - Float64(c / b))) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
code[a_, b_, c_] := N[(N[(-0.25 * N[(N[(N[Power[N[(c * a), $MachinePrecision], 4.0], $MachinePrecision] / a), $MachinePrecision] * N[(20.0 / N[Power[b, 7.0], $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[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.25, \frac{{\left(c \cdot a\right)}^{4}}{a} \cdot \frac{20}{{b}^{7}}, \frac{-2 \cdot {c}^{3}}{\frac{{b}^{5}}{a \cdot a}} - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 15.1%
fma-neg15.2%
*-commutative15.2%
distribute-rgt-neg-in15.2%
*-commutative15.2%
distribute-rgt-neg-in15.2%
metadata-eval15.2%
Applied egg-rr15.2%
div-inv15.2%
*-commutative15.2%
Applied egg-rr15.2%
*-commutative15.2%
*-commutative15.2%
associate-/r*15.2%
metadata-eval15.2%
+-commutative15.2%
unsub-neg15.2%
*-commutative15.2%
associate-*l*15.2%
Simplified15.2%
Taylor expanded in b around inf 98.3%
+-commutative98.3%
mul-1-neg98.3%
unsub-neg98.3%
Simplified98.3%
Taylor expanded in b around 0 98.3%
distribute-rgt-out98.3%
times-frac98.3%
Simplified98.3%
Final simplification98.3%
(FPCore (a b c) :precision binary64 (- (- (/ (* -2.0 (pow c 3.0)) (/ (pow b 5.0) (* a a))) (/ c b)) (* a (/ c (/ (pow b 3.0) c)))))
double code(double a, double b, double c) {
return (((-2.0 * pow(c, 3.0)) / (pow(b, 5.0) / (a * a))) - (c / b)) - (a * (c / (pow(b, 3.0) / 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) * (c ** 3.0d0)) / ((b ** 5.0d0) / (a * a))) - (c / b)) - (a * (c / ((b ** 3.0d0) / c)))
end function
public static double code(double a, double b, double c) {
return (((-2.0 * Math.pow(c, 3.0)) / (Math.pow(b, 5.0) / (a * a))) - (c / b)) - (a * (c / (Math.pow(b, 3.0) / c)));
}
def code(a, b, c): return (((-2.0 * math.pow(c, 3.0)) / (math.pow(b, 5.0) / (a * a))) - (c / b)) - (a * (c / (math.pow(b, 3.0) / c)))
function code(a, b, c) return Float64(Float64(Float64(Float64(-2.0 * (c ^ 3.0)) / Float64((b ^ 5.0) / Float64(a * a))) - Float64(c / b)) - Float64(a * Float64(c / Float64((b ^ 3.0) / c)))) end
function tmp = code(a, b, c) tmp = (((-2.0 * (c ^ 3.0)) / ((b ^ 5.0) / (a * a))) - (c / b)) - (a * (c / ((b ^ 3.0) / c))); end
code[a_, b_, c_] := N[(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] - N[(a * N[(c / N[(N[Power[b, 3.0], $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{-2 \cdot {c}^{3}}{\frac{{b}^{5}}{a \cdot a}} - \frac{c}{b}\right) - a \cdot \frac{c}{\frac{{b}^{3}}{c}}
\end{array}
Initial program 15.1%
Taylor expanded in b around inf 97.5%
+-commutative97.5%
mul-1-neg97.5%
unsub-neg97.5%
+-commutative97.5%
mul-1-neg97.5%
unsub-neg97.5%
associate-/l*97.5%
associate-*r/97.5%
unpow297.5%
associate-/l*97.5%
associate-/r/97.5%
Simplified97.5%
Final simplification97.5%
(FPCore (a b c) :precision binary64 (- (/ (- c) b) (* a (/ c (/ (pow b 3.0) c)))))
double code(double a, double b, double c) {
return (-c / b) - (a * (c / (pow(b, 3.0) / 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 * (c / ((b ** 3.0d0) / c)))
end function
public static double code(double a, double b, double c) {
return (-c / b) - (a * (c / (Math.pow(b, 3.0) / c)));
}
def code(a, b, c): return (-c / b) - (a * (c / (math.pow(b, 3.0) / c)))
function code(a, b, c) return Float64(Float64(Float64(-c) / b) - Float64(a * Float64(c / Float64((b ^ 3.0) / c)))) end
function tmp = code(a, b, c) tmp = (-c / b) - (a * (c / ((b ^ 3.0) / c))); end
code[a_, b_, c_] := N[(N[((-c) / b), $MachinePrecision] - N[(a * N[(c / N[(N[Power[b, 3.0], $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-c}{b} - a \cdot \frac{c}{\frac{{b}^{3}}{c}}
\end{array}
Initial program 15.1%
Taylor expanded in b around inf 96.0%
+-commutative96.0%
mul-1-neg96.0%
unsub-neg96.0%
associate-*r/96.0%
neg-mul-196.0%
associate-/l*96.0%
associate-/r/96.0%
unpow296.0%
associate-/l*96.0%
Simplified96.0%
Final simplification96.0%
(FPCore (a b c) :precision binary64 (/ (/ (* c (* a 4.0)) (- (- (+ b b)) (* -2.0 (* a (/ c b))))) (* a 2.0)))
double code(double a, double b, double c) {
return ((c * (a * 4.0)) / (-(b + b) - (-2.0 * (a * (c / b))))) / (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 = ((c * (a * 4.0d0)) / (-(b + b) - ((-2.0d0) * (a * (c / b))))) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
return ((c * (a * 4.0)) / (-(b + b) - (-2.0 * (a * (c / b))))) / (a * 2.0);
}
def code(a, b, c): return ((c * (a * 4.0)) / (-(b + b) - (-2.0 * (a * (c / b))))) / (a * 2.0)
function code(a, b, c) return Float64(Float64(Float64(c * Float64(a * 4.0)) / Float64(Float64(-Float64(b + b)) - Float64(-2.0 * Float64(a * Float64(c / b))))) / Float64(a * 2.0)) end
function tmp = code(a, b, c) tmp = ((c * (a * 4.0)) / (-(b + b) - (-2.0 * (a * (c / b))))) / (a * 2.0); end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision] / N[((-N[(b + b), $MachinePrecision]) - N[(-2.0 * N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{c \cdot \left(a \cdot 4\right)}{\left(-\left(b + b\right)\right) - -2 \cdot \left(a \cdot \frac{c}{b}\right)}}{a \cdot 2}
\end{array}
Initial program 15.1%
Taylor expanded in b around inf 10.8%
flip-+10.7%
associate-/l*10.7%
associate-/l*10.7%
associate-/l*10.7%
Applied egg-rr10.7%
sqr-neg10.7%
associate-/l*10.7%
associate-*l/10.7%
associate-/l*10.7%
associate-*l/10.7%
associate--r+10.7%
associate-/r/10.7%
Simplified10.7%
Taylor expanded in b around inf 95.7%
*-commutative95.7%
associate-*l*95.7%
Simplified95.7%
Final simplification95.7%
(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 15.1%
Taylor expanded in b around inf 92.4%
associate-*r/92.4%
neg-mul-192.4%
Simplified92.4%
Final simplification92.4%
herbie shell --seed 2023187
(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)))