
(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 (/ -1.0 (/ 2.0 (/ (* c 4.0) (+ b (sqrt (fma b b (* (* c a) -4.0))))))))
double code(double a, double b, double c) {
return -1.0 / (2.0 / ((c * 4.0) / (b + sqrt(fma(b, b, ((c * a) * -4.0))))));
}
function code(a, b, c) return Float64(-1.0 / Float64(2.0 / Float64(Float64(c * 4.0) / Float64(b + sqrt(fma(b, b, Float64(Float64(c * a) * -4.0))))))) end
code[a_, b_, c_] := N[(-1.0 / N[(2.0 / N[(N[(c * 4.0), $MachinePrecision] / N[(b + N[Sqrt[N[(b * b + N[(N[(c * a), $MachinePrecision] * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{\frac{2}{\frac{c \cdot 4}{b + \sqrt{\mathsf{fma}\left(b, b, \left(c \cdot a\right) \cdot -4\right)}}}}
\end{array}
Initial program 16.8%
*-commutative16.8%
Simplified16.8%
add-exp-log16.8%
associate-*l*16.8%
Applied egg-rr16.8%
flip-+16.7%
pow216.7%
add-sqr-sqrt17.1%
pow217.1%
rem-exp-log17.2%
associate-*r*17.2%
pow217.2%
rem-exp-log17.2%
associate-*r*17.2%
Applied egg-rr17.2%
Taylor expanded in b around 0 99.5%
*-commutative99.5%
associate-*l*99.5%
Simplified99.5%
clear-num99.3%
inv-pow99.3%
associate-/l*99.5%
*-commutative99.5%
*-commutative99.5%
Applied egg-rr99.5%
unpow-199.5%
times-frac99.7%
*-inverses99.7%
unpow299.7%
associate-*r*99.7%
*-commutative99.7%
associate-*r*99.7%
fma-neg99.7%
associate-*r*99.7%
distribute-rgt-neg-in99.7%
metadata-eval99.7%
Simplified99.7%
Final simplification99.7%
(FPCore (a b c) :precision binary64 (/ (/ (* (* c 4.0) a) (- (- b) (sqrt (- (* b b) (* c (* 4.0 a)))))) (* 2.0 a)))
double code(double a, double b, double c) {
return (((c * 4.0) * a) / (-b - sqrt(((b * b) - (c * (4.0 * a)))))) / (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 = (((c * 4.0d0) * a) / (-b - sqrt(((b * b) - (c * (4.0d0 * a)))))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (((c * 4.0) * a) / (-b - Math.sqrt(((b * b) - (c * (4.0 * a)))))) / (2.0 * a);
}
def code(a, b, c): return (((c * 4.0) * a) / (-b - math.sqrt(((b * b) - (c * (4.0 * a)))))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(Float64(c * 4.0) * a) / Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(c * Float64(4.0 * a)))))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (((c * 4.0) * a) / (-b - sqrt(((b * b) - (c * (4.0 * a)))))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[(N[(N[(c * 4.0), $MachinePrecision] * a), $MachinePrecision] / N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(4.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\left(c \cdot 4\right) \cdot a}{\left(-b\right) - \sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)}}}{2 \cdot a}
\end{array}
Initial program 16.8%
*-commutative16.8%
Simplified16.8%
add-exp-log16.8%
associate-*l*16.8%
Applied egg-rr16.8%
flip-+16.7%
pow216.7%
add-sqr-sqrt17.1%
pow217.1%
rem-exp-log17.2%
associate-*r*17.2%
pow217.2%
rem-exp-log17.2%
associate-*r*17.2%
Applied egg-rr17.2%
Taylor expanded in b around 0 99.5%
*-commutative99.5%
associate-*l*99.5%
Simplified99.5%
unpow299.5%
Applied egg-rr99.5%
Final simplification99.5%
(FPCore (a b c) :precision binary64 (/ (- (- c) (* a (pow (/ c (- b)) 2.0))) b))
double code(double a, double b, double c) {
return (-c - (a * pow((c / -b), 2.0))) / 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) ** 2.0d0))) / b
end function
public static double code(double a, double b, double c) {
return (-c - (a * Math.pow((c / -b), 2.0))) / b;
}
def code(a, b, c): return (-c - (a * math.pow((c / -b), 2.0))) / b
function code(a, b, c) return Float64(Float64(Float64(-c) - Float64(a * (Float64(c / Float64(-b)) ^ 2.0))) / b) end
function tmp = code(a, b, c) tmp = (-c - (a * ((c / -b) ^ 2.0))) / b; end
code[a_, b_, c_] := N[(N[((-c) - N[(a * N[Power[N[(c / (-b)), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-c\right) - a \cdot {\left(\frac{c}{-b}\right)}^{2}}{b}
\end{array}
Initial program 16.8%
*-commutative16.8%
Simplified16.8%
Taylor expanded in c around 0 97.2%
Simplified97.2%
Taylor expanded in b around inf 95.1%
neg-mul-195.1%
mul-1-neg95.1%
unsub-neg95.1%
associate-/l*95.1%
unpow295.1%
unpow295.1%
times-frac95.1%
sqr-neg95.1%
distribute-frac-neg95.1%
distribute-frac-neg95.1%
unpow195.1%
pow-plus95.1%
distribute-frac-neg95.1%
distribute-neg-frac295.1%
metadata-eval95.1%
Simplified95.1%
(FPCore (a b c) :precision binary64 (/ (/ (* (* c 4.0) a) (* 2.0 (- (* a (/ c b)) b))) (* 2.0 a)))
double code(double a, double b, double c) {
return (((c * 4.0) * a) / (2.0 * ((a * (c / b)) - b))) / (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 = (((c * 4.0d0) * a) / (2.0d0 * ((a * (c / b)) - b))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (((c * 4.0) * a) / (2.0 * ((a * (c / b)) - b))) / (2.0 * a);
}
def code(a, b, c): return (((c * 4.0) * a) / (2.0 * ((a * (c / b)) - b))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(Float64(c * 4.0) * a) / Float64(2.0 * Float64(Float64(a * Float64(c / b)) - b))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (((c * 4.0) * a) / (2.0 * ((a * (c / b)) - b))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[(N[(N[(c * 4.0), $MachinePrecision] * a), $MachinePrecision] / N[(2.0 * N[(N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{\left(c \cdot 4\right) \cdot a}{2 \cdot \left(a \cdot \frac{c}{b} - b\right)}}{2 \cdot a}
\end{array}
Initial program 16.8%
*-commutative16.8%
Simplified16.8%
add-exp-log16.8%
associate-*l*16.8%
Applied egg-rr16.8%
flip-+16.7%
pow216.7%
add-sqr-sqrt17.1%
pow217.1%
rem-exp-log17.2%
associate-*r*17.2%
pow217.2%
rem-exp-log17.2%
associate-*r*17.2%
Applied egg-rr17.2%
Taylor expanded in b around 0 99.5%
*-commutative99.5%
associate-*l*99.5%
Simplified99.5%
Taylor expanded in a around 0 94.9%
distribute-lft-out--94.9%
associate-/l*94.9%
Simplified94.9%
Final simplification94.9%
(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(c / Float64(-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 16.8%
*-commutative16.8%
Simplified16.8%
Taylor expanded in b around inf 91.0%
associate-*r/91.0%
mul-1-neg91.0%
Simplified91.0%
Final simplification91.0%
herbie shell --seed 2024116
(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)))