
(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 (/ (* -2.0 c) (+ (sqrt (fma (* -4.0 c) a (* b b))) b)))
double code(double a, double b, double c) {
return (-2.0 * c) / (sqrt(fma((-4.0 * c), a, (b * b))) + b);
}
function code(a, b, c) return Float64(Float64(-2.0 * c) / Float64(sqrt(fma(Float64(-4.0 * c), a, Float64(b * b))) + b)) end
code[a_, b_, c_] := N[(N[(-2.0 * c), $MachinePrecision] / N[(N[Sqrt[N[(N[(-4.0 * c), $MachinePrecision] * a + N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2 \cdot c}{\sqrt{\mathsf{fma}\left(-4 \cdot c, a, b \cdot b\right)} + b}
\end{array}
Initial program 30.3%
lift--.f64N/A
sub-negN/A
lift-*.f64N/A
lower-fma.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
distribute-lft-neg-inN/A
*-commutativeN/A
associate-*r*N/A
lower-*.f64N/A
lower-*.f64N/A
metadata-eval30.3
Applied rewrites30.3%
lift-/.f64N/A
lift-+.f64N/A
+-commutativeN/A
lift-fma.f64N/A
lift-*.f64N/A
+-commutativeN/A
lift-*.f64N/A
lift-fma.f64N/A
lift-neg.f64N/A
sub-negN/A
flip--N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites31.0%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lower-/.f64N/A
div-invN/A
lower-*.f64N/A
lift--.f64N/A
lift-fma.f64N/A
associate--l+N/A
+-inversesN/A
lower-fma.f64N/A
lift-*.f64N/A
associate-/r*N/A
metadata-evalN/A
lower-/.f6499.4
Applied rewrites99.4%
Taylor expanded in a around 0
lower-*.f6499.8
Applied rewrites99.8%
(FPCore (a b c) :precision binary64 (pow (/ (fma a (/ c b) (- b)) c) -1.0))
double code(double a, double b, double c) {
return pow((fma(a, (c / b), -b) / c), -1.0);
}
function code(a, b, c) return Float64(fma(a, Float64(c / b), Float64(-b)) / c) ^ -1.0 end
code[a_, b_, c_] := N[Power[N[(N[(a * N[(c / b), $MachinePrecision] + (-b)), $MachinePrecision] / c), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{\mathsf{fma}\left(a, \frac{c}{b}, -b\right)}{c}\right)}^{-1}
\end{array}
Initial program 30.3%
lift--.f64N/A
sub-negN/A
lift-*.f64N/A
lower-fma.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
distribute-lft-neg-inN/A
*-commutativeN/A
associate-*r*N/A
lower-*.f64N/A
lower-*.f64N/A
metadata-eval30.3
Applied rewrites30.3%
lift-/.f64N/A
lift-+.f64N/A
+-commutativeN/A
lift-fma.f64N/A
lift-*.f64N/A
+-commutativeN/A
lift-*.f64N/A
lift-fma.f64N/A
lift-neg.f64N/A
sub-negN/A
flip--N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites31.0%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
clear-numN/A
lower-/.f64N/A
lower-/.f64N/A
div-invN/A
lower-*.f64N/A
Applied rewrites99.2%
Taylor expanded in c around 0
lower-/.f64N/A
+-commutativeN/A
associate-/l*N/A
lower-fma.f64N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6491.8
Applied rewrites91.8%
Final simplification91.8%
(FPCore (a b c) :precision binary64 (pow (- (/ a b) (/ b c)) -1.0))
double code(double a, double b, double c) {
return pow(((a / b) - (b / c)), -1.0);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = ((a / b) - (b / c)) ** (-1.0d0)
end function
public static double code(double a, double b, double c) {
return Math.pow(((a / b) - (b / c)), -1.0);
}
def code(a, b, c): return math.pow(((a / b) - (b / c)), -1.0)
function code(a, b, c) return Float64(Float64(a / b) - Float64(b / c)) ^ -1.0 end
function tmp = code(a, b, c) tmp = ((a / b) - (b / c)) ^ -1.0; end
code[a_, b_, c_] := N[Power[N[(N[(a / b), $MachinePrecision] - N[(b / c), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{a}{b} - \frac{b}{c}\right)}^{-1}
\end{array}
Initial program 30.3%
lift--.f64N/A
sub-negN/A
lift-*.f64N/A
lower-fma.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
distribute-lft-neg-inN/A
*-commutativeN/A
associate-*r*N/A
lower-*.f64N/A
lower-*.f64N/A
metadata-eval30.3
Applied rewrites30.3%
lift-/.f64N/A
lift-+.f64N/A
+-commutativeN/A
lift-fma.f64N/A
lift-*.f64N/A
+-commutativeN/A
lift-*.f64N/A
lift-fma.f64N/A
lift-neg.f64N/A
sub-negN/A
flip--N/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites31.0%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
clear-numN/A
lower-/.f64N/A
lower-/.f64N/A
div-invN/A
lower-*.f64N/A
Applied rewrites99.2%
Taylor expanded in a around 0
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f64N/A
lower-/.f64N/A
lower-/.f6491.8
Applied rewrites91.8%
Final simplification91.8%
(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 30.3%
Taylor expanded in a around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6482.2
Applied rewrites82.2%
(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 / 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 30.3%
Taylor expanded in a around 0
associate-*r/N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6482.2
Applied rewrites82.2%
Applied rewrites82.0%
Applied rewrites82.0%
Applied rewrites1.6%
herbie shell --seed 2024322
(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)))