
(FPCore (x) :precision binary64 (+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))))
double code(double x) {
return (1.0 / (x - 1.0)) + (x / (x + 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x - 1.0d0)) + (x / (x + 1.0d0))
end function
public static double code(double x) {
return (1.0 / (x - 1.0)) + (x / (x + 1.0));
}
def code(x): return (1.0 / (x - 1.0)) + (x / (x + 1.0))
function code(x) return Float64(Float64(1.0 / Float64(x - 1.0)) + Float64(x / Float64(x + 1.0))) end
function tmp = code(x) tmp = (1.0 / (x - 1.0)) + (x / (x + 1.0)); end
code[x_] := N[(N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] + N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x - 1} + \frac{x}{x + 1}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))))
double code(double x) {
return (1.0 / (x - 1.0)) + (x / (x + 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x - 1.0d0)) + (x / (x + 1.0d0))
end function
public static double code(double x) {
return (1.0 / (x - 1.0)) + (x / (x + 1.0));
}
def code(x): return (1.0 / (x - 1.0)) + (x / (x + 1.0))
function code(x) return Float64(Float64(1.0 / Float64(x - 1.0)) + Float64(x / Float64(x + 1.0))) end
function tmp = code(x) tmp = (1.0 / (x - 1.0)) + (x / (x + 1.0)); end
code[x_] := N[(N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] + N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x - 1} + \frac{x}{x + 1}
\end{array}
(FPCore (x) :precision binary64 (+ (/ x (+ x 1.0)) (/ 1.0 (- x 1.0))))
double code(double x) {
return (x / (x + 1.0)) + (1.0 / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x / (x + 1.0d0)) + (1.0d0 / (x - 1.0d0))
end function
public static double code(double x) {
return (x / (x + 1.0)) + (1.0 / (x - 1.0));
}
def code(x): return (x / (x + 1.0)) + (1.0 / (x - 1.0))
function code(x) return Float64(Float64(x / Float64(x + 1.0)) + Float64(1.0 / Float64(x - 1.0))) end
function tmp = code(x) tmp = (x / (x + 1.0)) + (1.0 / (x - 1.0)); end
code[x_] := N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{x + 1} + \frac{1}{x - 1}
\end{array}
Initial program 100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (if (<= (+ (/ x (+ x 1.0)) (/ 1.0 (- x 1.0))) -1.0) (fma (* x x) -2.0 -1.0) (+ (/ 2.0 (* x x)) 1.0)))
double code(double x) {
double tmp;
if (((x / (x + 1.0)) + (1.0 / (x - 1.0))) <= -1.0) {
tmp = fma((x * x), -2.0, -1.0);
} else {
tmp = (2.0 / (x * x)) + 1.0;
}
return tmp;
}
function code(x) tmp = 0.0 if (Float64(Float64(x / Float64(x + 1.0)) + Float64(1.0 / Float64(x - 1.0))) <= -1.0) tmp = fma(Float64(x * x), -2.0, -1.0); else tmp = Float64(Float64(2.0 / Float64(x * x)) + 1.0); end return tmp end
code[x_] := If[LessEqual[N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0], N[(N[(x * x), $MachinePrecision] * -2.0 + -1.0), $MachinePrecision], N[(N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{x}{x + 1} + \frac{1}{x - 1} \leq -1:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, -2, -1\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{2}{x \cdot x} + 1\\
\end{array}
\end{array}
if (+.f64 (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64))) (/.f64 x (+.f64 x #s(literal 1 binary64)))) < -1Initial program 100.0%
Taylor expanded in x around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64100.0
Applied rewrites100.0%
if -1 < (+.f64 (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64))) (/.f64 x (+.f64 x #s(literal 1 binary64)))) Initial program 100.0%
Taylor expanded in x around inf
+-commutativeN/A
lower-+.f64N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f64N/A
unpow2N/A
lower-*.f6499.6
Applied rewrites99.6%
Final simplification99.8%
(FPCore (x) :precision binary64 (+ -1.0 (/ x (+ x 1.0))))
double code(double x) {
return -1.0 + (x / (x + 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) + (x / (x + 1.0d0))
end function
public static double code(double x) {
return -1.0 + (x / (x + 1.0));
}
def code(x): return -1.0 + (x / (x + 1.0))
function code(x) return Float64(-1.0 + Float64(x / Float64(x + 1.0))) end
function tmp = code(x) tmp = -1.0 + (x / (x + 1.0)); end
code[x_] := N[(-1.0 + N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-1 + \frac{x}{x + 1}
\end{array}
Initial program 100.0%
Taylor expanded in x around 0
Applied rewrites48.3%
(FPCore (x) :precision binary64 (+ (/ x 1.0) -1.0))
double code(double x) {
return (x / 1.0) + -1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x / 1.0d0) + (-1.0d0)
end function
public static double code(double x) {
return (x / 1.0) + -1.0;
}
def code(x): return (x / 1.0) + -1.0
function code(x) return Float64(Float64(x / 1.0) + -1.0) end
function tmp = code(x) tmp = (x / 1.0) + -1.0; end
code[x_] := N[(N[(x / 1.0), $MachinePrecision] + -1.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{1} + -1
\end{array}
Initial program 100.0%
Taylor expanded in x around 0
Applied rewrites48.3%
Taylor expanded in x around 0
Applied rewrites48.0%
Final simplification48.0%
(FPCore (x) :precision binary64 -1.0)
double code(double x) {
return -1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = -1.0d0
end function
public static double code(double x) {
return -1.0;
}
def code(x): return -1.0
function code(x) return -1.0 end
function tmp = code(x) tmp = -1.0; end
code[x_] := -1.0
\begin{array}{l}
\\
-1
\end{array}
Initial program 100.0%
Taylor expanded in x around inf
+-commutativeN/A
lower-+.f64N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f64N/A
unpow2N/A
lower-*.f6453.3
Applied rewrites53.3%
Taylor expanded in x around 0
Applied rewrites47.6%
herbie shell --seed 2024312
(FPCore (x)
:name "Asymptote B"
:precision binary64
(+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))))