
(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 (/ (/ (* 4.0 (* a c)) (- (- b) (sqrt (fma b b (* (* a c) -4.0))))) (* a 2.0)))
double code(double a, double b, double c) {
return ((4.0 * (a * c)) / (-b - sqrt(fma(b, b, ((a * c) * -4.0))))) / (a * 2.0);
}
function code(a, b, c) return Float64(Float64(Float64(4.0 * Float64(a * c)) / Float64(Float64(-b) - sqrt(fma(b, b, Float64(Float64(a * c) * -4.0))))) / Float64(a * 2.0)) end
code[a_, b_, c_] := N[(N[(N[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(b * b + N[(N[(a * c), $MachinePrecision] * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{4 \cdot \left(a \cdot c\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)}}}{a \cdot 2}
\end{array}
Initial program 32.0%
*-commutative32.0%
Simplified32.0%
add-sqr-sqrt32.1%
distribute-rgt-neg-in32.1%
Applied egg-rr32.1%
flip-+32.2%
Applied egg-rr33.0%
associate--r-99.3%
unpow299.3%
unpow299.3%
difference-of-squares99.3%
+-commutative99.3%
neg-mul-199.3%
distribute-rgt1-in99.3%
metadata-eval99.3%
mul0-lft99.3%
unpow299.3%
fmm-def99.3%
associate-*r*99.3%
*-commutative99.3%
distribute-rgt-neg-in99.3%
*-commutative99.3%
metadata-eval99.3%
Simplified99.3%
Taylor expanded in b around 0 99.3%
Final simplification99.3%
(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 32.0%
*-commutative32.0%
Simplified32.0%
Taylor expanded in b around inf 90.4%
mul-1-neg90.4%
unsub-neg90.4%
mul-1-neg90.4%
associate-/l*90.4%
Simplified90.4%
Taylor expanded in a around 0 90.4%
associate-*r/90.4%
unpow290.4%
unpow290.4%
times-frac90.4%
sqr-neg90.4%
distribute-frac-neg90.4%
distribute-frac-neg90.4%
unpow190.4%
pow-plus90.4%
distribute-frac-neg90.4%
distribute-neg-frac290.4%
metadata-eval90.4%
Simplified90.4%
(FPCore (a b c) :precision binary64 (/ (/ (* 4.0 (* a c)) (* 2.0 (- (* c (/ a b)) b))) (* a 2.0)))
double code(double a, double b, double c) {
return ((4.0 * (a * c)) / (2.0 * ((c * (a / b)) - 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 = ((4.0d0 * (a * c)) / (2.0d0 * ((c * (a / b)) - b))) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
return ((4.0 * (a * c)) / (2.0 * ((c * (a / b)) - b))) / (a * 2.0);
}
def code(a, b, c): return ((4.0 * (a * c)) / (2.0 * ((c * (a / b)) - b))) / (a * 2.0)
function code(a, b, c) return Float64(Float64(Float64(4.0 * Float64(a * c)) / Float64(2.0 * Float64(Float64(c * Float64(a / b)) - b))) / Float64(a * 2.0)) end
function tmp = code(a, b, c) tmp = ((4.0 * (a * c)) / (2.0 * ((c * (a / b)) - b))) / (a * 2.0); end
code[a_, b_, c_] := N[(N[(N[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision] / N[(2.0 * N[(N[(c * N[(a / b), $MachinePrecision]), $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{4 \cdot \left(a \cdot c\right)}{2 \cdot \left(c \cdot \frac{a}{b} - b\right)}}{a \cdot 2}
\end{array}
Initial program 32.0%
*-commutative32.0%
Simplified32.0%
add-sqr-sqrt32.1%
distribute-rgt-neg-in32.1%
Applied egg-rr32.1%
flip-+32.2%
Applied egg-rr33.0%
associate--r-99.3%
unpow299.3%
unpow299.3%
difference-of-squares99.3%
+-commutative99.3%
neg-mul-199.3%
distribute-rgt1-in99.3%
metadata-eval99.3%
mul0-lft99.3%
unpow299.3%
fmm-def99.3%
associate-*r*99.3%
*-commutative99.3%
distribute-rgt-neg-in99.3%
*-commutative99.3%
metadata-eval99.3%
Simplified99.3%
Taylor expanded in b around 0 99.3%
Taylor expanded in c around 0 90.4%
distribute-lft-out--90.4%
*-commutative90.4%
associate-/l*90.4%
Simplified90.4%
(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(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 32.0%
*-commutative32.0%
Simplified32.0%
Taylor expanded in a around 0 81.0%
associate-*r/81.0%
mul-1-neg81.0%
Simplified81.0%
Final simplification81.0%
(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 32.0%
*-commutative32.0%
Simplified32.0%
add-sqr-sqrt32.1%
distribute-rgt-neg-in32.1%
Applied egg-rr32.1%
Taylor expanded in a around 0 3.2%
associate-*r/3.2%
distribute-rgt1-in3.2%
metadata-eval3.2%
mul0-lft3.2%
metadata-eval3.2%
Simplified3.2%
herbie shell --seed 2024173
(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)))