
(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 a 3.0) (pow c 4.0))) (pow b 6.0)) 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(a, 3.0) * pow(c, 4.0))) / pow(b, 6.0)) / 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(Float64(-5.0 * Float64((a ^ 3.0) * (c ^ 4.0))) / (b ^ 6.0)) / 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[(N[(-5.0 * N[(N[Power[a, 3.0], $MachinePrecision] * N[Power[c, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 6.0], $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{\frac{-5 \cdot \left({a}^{3} \cdot {c}^{4}\right)}{{b}^{6}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 28.1%
/-rgt-identity28.1%
metadata-eval28.1%
associate-/l*28.1%
associate-*r/28.1%
+-commutative28.1%
unsub-neg28.1%
fma-neg28.1%
associate-*l*28.1%
*-commutative28.1%
distribute-rgt-neg-in28.1%
metadata-eval28.1%
associate-/r*28.1%
metadata-eval28.1%
metadata-eval28.1%
Simplified28.1%
Taylor expanded in a around 0 96.9%
Simplified96.9%
Taylor expanded in c around 0 96.9%
associate-*r/96.9%
*-commutative96.9%
Simplified96.9%
Final simplification96.9%
(FPCore (a b c) :precision binary64 (- (fma 0.03125 (/ (* (pow c 3.0) -64.0) (/ (pow b 5.0) (* a a))) (/ -0.0625 (/ (pow b 3.0) (* a (* (* c c) 16.0))))) (/ c b)))
double code(double a, double b, double c) {
return fma(0.03125, ((pow(c, 3.0) * -64.0) / (pow(b, 5.0) / (a * a))), (-0.0625 / (pow(b, 3.0) / (a * ((c * c) * 16.0))))) - (c / b);
}
function code(a, b, c) return Float64(fma(0.03125, Float64(Float64((c ^ 3.0) * -64.0) / Float64((b ^ 5.0) / Float64(a * a))), Float64(-0.0625 / Float64((b ^ 3.0) / Float64(a * Float64(Float64(c * c) * 16.0))))) - Float64(c / b)) end
code[a_, b_, c_] := N[(N[(0.03125 * N[(N[(N[Power[c, 3.0], $MachinePrecision] * -64.0), $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.0625 / N[(N[Power[b, 3.0], $MachinePrecision] / N[(a * N[(N[(c * c), $MachinePrecision] * 16.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(0.03125, \frac{{c}^{3} \cdot -64}{\frac{{b}^{5}}{a \cdot a}}, \frac{-0.0625}{\frac{{b}^{3}}{a \cdot \left(\left(c \cdot c\right) \cdot 16\right)}}\right) - \frac{c}{b}
\end{array}
Initial program 28.1%
*-commutative28.1%
+-commutative28.1%
unsub-neg28.1%
fma-neg28.1%
associate-*l*28.1%
*-commutative28.1%
distribute-rgt-neg-in28.1%
metadata-eval28.1%
Simplified28.1%
fma-udef28.1%
*-commutative28.1%
metadata-eval28.1%
cancel-sign-sub-inv28.1%
associate-*l*28.1%
*-un-lft-identity28.1%
prod-diff28.1%
Applied egg-rr28.1%
Taylor expanded in a around 0 95.7%
associate-*r/95.7%
distribute-rgt-out--95.7%
metadata-eval95.7%
*-commutative95.7%
associate-*r*95.7%
metadata-eval95.7%
neg-mul-195.7%
+-commutative95.7%
fma-def95.7%
Simplified95.7%
Final simplification95.7%
(FPCore (a b c) :precision binary64 (- (fma -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(-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(-2.0, Float64((c ^ 3.0) / Float64((b ^ 5.0) / Float64(a * a))), Float64(Float64(-c) / b)) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a))) end
code[a_, b_, c_] := 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[((-c) / b), $MachinePrecision]), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{-c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Initial program 28.1%
/-rgt-identity28.1%
metadata-eval28.1%
associate-/l*28.1%
associate-*r/28.1%
+-commutative28.1%
unsub-neg28.1%
fma-neg28.1%
associate-*l*28.1%
*-commutative28.1%
distribute-rgt-neg-in28.1%
metadata-eval28.1%
associate-/r*28.1%
metadata-eval28.1%
metadata-eval28.1%
Simplified28.1%
Taylor expanded in b around inf 95.7%
+-commutative95.7%
mul-1-neg95.7%
unsub-neg95.7%
+-commutative95.7%
fma-def95.7%
associate-/l*95.7%
unpow295.7%
mul-1-neg95.7%
distribute-neg-frac95.7%
associate-/l*95.7%
unpow295.7%
Simplified95.7%
Final simplification95.7%
(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 28.1%
/-rgt-identity28.1%
metadata-eval28.1%
associate-/l*28.1%
associate-*r/28.1%
+-commutative28.1%
unsub-neg28.1%
fma-neg28.1%
associate-*l*28.1%
*-commutative28.1%
distribute-rgt-neg-in28.1%
metadata-eval28.1%
associate-/r*28.1%
metadata-eval28.1%
metadata-eval28.1%
Simplified28.1%
Taylor expanded in b around inf 93.1%
+-commutative93.1%
mul-1-neg93.1%
unsub-neg93.1%
mul-1-neg93.1%
distribute-neg-frac93.1%
associate-/l*93.1%
unpow293.1%
Simplified93.1%
Final simplification93.1%
(FPCore (a b c) :precision binary64 (* (/ (* c (* a -4.0)) (+ b (+ b (* -2.0 (* a (/ c b)))))) (/ 0.5 a)))
double code(double a, double b, double c) {
return ((c * (a * -4.0)) / (b + (b + (-2.0 * (a * (c / b)))))) * (0.5 / 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 * (a * (-4.0d0))) / (b + (b + ((-2.0d0) * (a * (c / b)))))) * (0.5d0 / a)
end function
public static double code(double a, double b, double c) {
return ((c * (a * -4.0)) / (b + (b + (-2.0 * (a * (c / b)))))) * (0.5 / a);
}
def code(a, b, c): return ((c * (a * -4.0)) / (b + (b + (-2.0 * (a * (c / b)))))) * (0.5 / a)
function code(a, b, c) return Float64(Float64(Float64(c * Float64(a * -4.0)) / Float64(b + Float64(b + Float64(-2.0 * Float64(a * Float64(c / b)))))) * Float64(0.5 / a)) end
function tmp = code(a, b, c) tmp = ((c * (a * -4.0)) / (b + (b + (-2.0 * (a * (c / b)))))) * (0.5 / a); end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[(b + N[(-2.0 * N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(0.5 / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{c \cdot \left(a \cdot -4\right)}{b + \left(b + -2 \cdot \left(a \cdot \frac{c}{b}\right)\right)} \cdot \frac{0.5}{a}
\end{array}
Initial program 28.1%
/-rgt-identity28.1%
metadata-eval28.1%
associate-/l*28.1%
associate-*r/28.1%
+-commutative28.1%
unsub-neg28.1%
fma-neg28.1%
associate-*l*28.1%
*-commutative28.1%
distribute-rgt-neg-in28.1%
metadata-eval28.1%
associate-/r*28.1%
metadata-eval28.1%
metadata-eval28.1%
Simplified28.1%
Taylor expanded in b around inf 20.8%
associate-*r/20.8%
Simplified20.8%
flip--20.8%
associate-*r/20.8%
associate-/l*20.8%
associate-/r/20.8%
associate-*r/20.8%
associate-/l*20.8%
associate-/r/20.8%
associate-*r/20.8%
associate-/l*20.8%
associate-/r/20.8%
Applied egg-rr20.8%
Taylor expanded in b around inf 92.9%
*-commutative92.9%
*-commutative92.9%
*-commutative92.9%
associate-*r*92.9%
Simplified92.9%
Final simplification92.9%
(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 28.1%
/-rgt-identity28.1%
metadata-eval28.1%
associate-/l*28.1%
associate-*r/28.1%
+-commutative28.1%
unsub-neg28.1%
fma-neg28.1%
associate-*l*28.1%
*-commutative28.1%
distribute-rgt-neg-in28.1%
metadata-eval28.1%
associate-/r*28.1%
metadata-eval28.1%
metadata-eval28.1%
Simplified28.1%
Taylor expanded in b around inf 84.0%
mul-1-neg84.0%
distribute-neg-frac84.0%
Simplified84.0%
Final simplification84.0%
herbie shell --seed 2023208
(FPCore (a b c)
:name "Quadratic roots, medium range"
:precision binary64
:pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))