
(FPCore (x) :precision binary64 (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))
double code(double x) {
return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + 1.0d0)) - (1.0d0 / (x - 1.0d0))
end function
public static double code(double x) {
return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}
def code(x): return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0))
function code(x) return Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(1.0 / Float64(x - 1.0))) end
function tmp = code(x) tmp = (1.0 / (x + 1.0)) - (1.0 / (x - 1.0)); end
code[x_] := N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + 1} - \frac{1}{x - 1}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))
double code(double x) {
return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + 1.0d0)) - (1.0d0 / (x - 1.0d0))
end function
public static double code(double x) {
return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}
def code(x): return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0))
function code(x) return Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(1.0 / Float64(x - 1.0))) end
function tmp = code(x) tmp = (1.0 / (x + 1.0)) - (1.0 / (x - 1.0)); end
code[x_] := N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + 1} - \frac{1}{x - 1}
\end{array}
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (/ (/ -2.0 (- 1.0 x_m)) (- -1.0 x_m)))
x_m = fabs(x);
double code(double x_m) {
return (-2.0 / (1.0 - x_m)) / (-1.0 - x_m);
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = ((-2.0d0) / (1.0d0 - x_m)) / ((-1.0d0) - x_m)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return (-2.0 / (1.0 - x_m)) / (-1.0 - x_m);
}
x_m = math.fabs(x) def code(x_m): return (-2.0 / (1.0 - x_m)) / (-1.0 - x_m)
x_m = abs(x) function code(x_m) return Float64(Float64(-2.0 / Float64(1.0 - x_m)) / Float64(-1.0 - x_m)) end
x_m = abs(x); function tmp = code(x_m) tmp = (-2.0 / (1.0 - x_m)) / (-1.0 - x_m); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(N[(-2.0 / N[(1.0 - x$95$m), $MachinePrecision]), $MachinePrecision] / N[(-1.0 - x$95$m), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{\frac{-2}{1 - x_m}}{-1 - x_m}
\end{array}
Initial program 79.1%
sub-neg79.1%
+-commutative79.1%
distribute-neg-frac79.1%
metadata-eval79.1%
metadata-eval79.1%
metadata-eval79.1%
associate-/r*79.1%
metadata-eval79.1%
neg-mul-179.1%
sub0-neg79.1%
associate-+l-79.1%
neg-sub079.1%
metadata-eval79.1%
metadata-eval79.1%
metadata-eval79.1%
associate-/r*79.1%
metadata-eval79.1%
neg-mul-179.1%
distribute-neg-in79.1%
sub-neg79.1%
distribute-neg-frac79.1%
neg-mul-179.1%
Simplified79.1%
sub-neg79.1%
distribute-neg-frac79.1%
metadata-eval79.1%
Applied egg-rr79.1%
Simplified99.6%
*-un-lft-identity99.6%
*-commutative99.6%
associate-/r*99.9%
Applied egg-rr99.9%
Final simplification99.9%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (/ -2.0 (* (- 1.0 x_m) (- -1.0 x_m))))
x_m = fabs(x);
double code(double x_m) {
return -2.0 / ((1.0 - x_m) * (-1.0 - x_m));
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = (-2.0d0) / ((1.0d0 - x_m) * ((-1.0d0) - x_m))
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return -2.0 / ((1.0 - x_m) * (-1.0 - x_m));
}
x_m = math.fabs(x) def code(x_m): return -2.0 / ((1.0 - x_m) * (-1.0 - x_m))
x_m = abs(x) function code(x_m) return Float64(-2.0 / Float64(Float64(1.0 - x_m) * Float64(-1.0 - x_m))) end
x_m = abs(x); function tmp = code(x_m) tmp = -2.0 / ((1.0 - x_m) * (-1.0 - x_m)); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(-2.0 / N[(N[(1.0 - x$95$m), $MachinePrecision] * N[(-1.0 - x$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{-2}{\left(1 - x_m\right) \cdot \left(-1 - x_m\right)}
\end{array}
Initial program 79.1%
sub-neg79.1%
+-commutative79.1%
distribute-neg-frac79.1%
metadata-eval79.1%
metadata-eval79.1%
metadata-eval79.1%
associate-/r*79.1%
metadata-eval79.1%
neg-mul-179.1%
sub0-neg79.1%
associate-+l-79.1%
neg-sub079.1%
metadata-eval79.1%
metadata-eval79.1%
metadata-eval79.1%
associate-/r*79.1%
metadata-eval79.1%
neg-mul-179.1%
distribute-neg-in79.1%
sub-neg79.1%
distribute-neg-frac79.1%
neg-mul-179.1%
Simplified79.1%
sub-neg79.1%
distribute-neg-frac79.1%
metadata-eval79.1%
Applied egg-rr79.1%
Simplified99.6%
Final simplification99.6%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 1.0)
x_m = fabs(x);
double code(double x_m) {
return 1.0;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = 1.0d0
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return 1.0;
}
x_m = math.fabs(x) def code(x_m): return 1.0
x_m = abs(x) function code(x_m) return 1.0 end
x_m = abs(x); function tmp = code(x_m) tmp = 1.0; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := 1.0
\begin{array}{l}
x_m = \left|x\right|
\\
1
\end{array}
Initial program 79.1%
sub-neg79.1%
+-commutative79.1%
distribute-neg-frac79.1%
metadata-eval79.1%
metadata-eval79.1%
metadata-eval79.1%
associate-/r*79.1%
metadata-eval79.1%
neg-mul-179.1%
sub0-neg79.1%
associate-+l-79.1%
neg-sub079.1%
metadata-eval79.1%
metadata-eval79.1%
metadata-eval79.1%
associate-/r*79.1%
metadata-eval79.1%
neg-mul-179.1%
distribute-neg-in79.1%
sub-neg79.1%
distribute-neg-frac79.1%
neg-mul-179.1%
Simplified79.1%
Taylor expanded in x around 0 52.6%
Taylor expanded in x around inf 11.2%
Final simplification11.2%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 2.0)
x_m = fabs(x);
double code(double x_m) {
return 2.0;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = 2.0d0
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return 2.0;
}
x_m = math.fabs(x) def code(x_m): return 2.0
x_m = abs(x) function code(x_m) return 2.0 end
x_m = abs(x); function tmp = code(x_m) tmp = 2.0; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := 2.0
\begin{array}{l}
x_m = \left|x\right|
\\
2
\end{array}
Initial program 79.1%
sub-neg79.1%
+-commutative79.1%
distribute-neg-frac79.1%
metadata-eval79.1%
metadata-eval79.1%
metadata-eval79.1%
associate-/r*79.1%
metadata-eval79.1%
neg-mul-179.1%
sub0-neg79.1%
associate-+l-79.1%
neg-sub079.1%
metadata-eval79.1%
metadata-eval79.1%
metadata-eval79.1%
associate-/r*79.1%
metadata-eval79.1%
neg-mul-179.1%
distribute-neg-in79.1%
sub-neg79.1%
distribute-neg-frac79.1%
neg-mul-179.1%
Simplified79.1%
Taylor expanded in x around 0 53.1%
Final simplification53.1%
herbie shell --seed 2024023
(FPCore (x)
:name "Asymptote A"
:precision binary64
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))