
(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 6 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 (+ x_m -1.0)) (+ x_m 1.0)))
x_m = fabs(x);
double code(double x_m) {
return (-2.0 / (x_m + -1.0)) / (x_m + 1.0);
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = ((-2.0d0) / (x_m + (-1.0d0))) / (x_m + 1.0d0)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return (-2.0 / (x_m + -1.0)) / (x_m + 1.0);
}
x_m = math.fabs(x) def code(x_m): return (-2.0 / (x_m + -1.0)) / (x_m + 1.0)
x_m = abs(x) function code(x_m) return Float64(Float64(-2.0 / Float64(x_m + -1.0)) / Float64(x_m + 1.0)) end
x_m = abs(x); function tmp = code(x_m) tmp = (-2.0 / (x_m + -1.0)) / (x_m + 1.0); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(N[(-2.0 / N[(x$95$m + -1.0), $MachinePrecision]), $MachinePrecision] / N[(x$95$m + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{\frac{-2}{x\_m + -1}}{x\_m + 1}
\end{array}
Initial program 77.9%
clear-numN/A
frac-subN/A
div-invN/A
metadata-evalN/A
*-rgt-identityN/A
*-commutativeN/A
associate-/r*N/A
/-lowering-/.f64N/A
Applied egg-rr78.8%
Taylor expanded in x around 0
Simplified99.9%
Final simplification99.9%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (if (<= (+ (/ 1.0 (+ x_m 1.0)) (/ -1.0 (+ x_m -1.0))) 0.0) (/ -2.0 (* x_m x_m)) (fma 2.0 (* x_m x_m) 2.0)))
x_m = fabs(x);
double code(double x_m) {
double tmp;
if (((1.0 / (x_m + 1.0)) + (-1.0 / (x_m + -1.0))) <= 0.0) {
tmp = -2.0 / (x_m * x_m);
} else {
tmp = fma(2.0, (x_m * x_m), 2.0);
}
return tmp;
}
x_m = abs(x) function code(x_m) tmp = 0.0 if (Float64(Float64(1.0 / Float64(x_m + 1.0)) + Float64(-1.0 / Float64(x_m + -1.0))) <= 0.0) tmp = Float64(-2.0 / Float64(x_m * x_m)); else tmp = fma(2.0, Float64(x_m * x_m), 2.0); end return tmp end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := If[LessEqual[N[(N[(1.0 / N[(x$95$m + 1.0), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / N[(x$95$m + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.0], N[(-2.0 / N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision], N[(2.0 * N[(x$95$m * x$95$m), $MachinePrecision] + 2.0), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
\mathbf{if}\;\frac{1}{x\_m + 1} + \frac{-1}{x\_m + -1} \leq 0:\\
\;\;\;\;\frac{-2}{x\_m \cdot x\_m}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(2, x\_m \cdot x\_m, 2\right)\\
\end{array}
\end{array}
if (-.f64 (/.f64 #s(literal 1 binary64) (+.f64 x #s(literal 1 binary64))) (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64)))) < 0.0Initial program 55.6%
Taylor expanded in x around inf
/-lowering-/.f64N/A
unpow2N/A
*-lowering-*.f6497.3
Simplified97.3%
if 0.0 < (-.f64 (/.f64 #s(literal 1 binary64) (+.f64 x #s(literal 1 binary64))) (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64)))) Initial program 100.0%
Taylor expanded in x around 0
+-commutativeN/A
accelerator-lowering-fma.f64N/A
unpow2N/A
*-lowering-*.f6498.8
Simplified98.8%
Final simplification98.1%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (/ -2.0 (fma x_m x_m -1.0)))
x_m = fabs(x);
double code(double x_m) {
return -2.0 / fma(x_m, x_m, -1.0);
}
x_m = abs(x) function code(x_m) return Float64(-2.0 / fma(x_m, x_m, -1.0)) end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(-2.0 / N[(x$95$m * x$95$m + -1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{-2}{\mathsf{fma}\left(x\_m, x\_m, -1\right)}
\end{array}
Initial program 77.9%
sub-negN/A
+-commutativeN/A
distribute-neg-fracN/A
metadata-evalN/A
clear-numN/A
frac-addN/A
*-commutativeN/A
div-invN/A
metadata-evalN/A
*-rgt-identityN/A
difference-of-sqr-1N/A
metadata-evalN/A
/-lowering-/.f64N/A
Applied egg-rr78.9%
Taylor expanded in x around 0
Simplified99.0%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (/ 2.0 (+ x_m 1.0)))
x_m = fabs(x);
double code(double x_m) {
return 2.0 / (x_m + 1.0);
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = 2.0d0 / (x_m + 1.0d0)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return 2.0 / (x_m + 1.0);
}
x_m = math.fabs(x) def code(x_m): return 2.0 / (x_m + 1.0)
x_m = abs(x) function code(x_m) return Float64(2.0 / Float64(x_m + 1.0)) end
x_m = abs(x); function tmp = code(x_m) tmp = 2.0 / (x_m + 1.0); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(2.0 / N[(x$95$m + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{2}{x\_m + 1}
\end{array}
Initial program 77.9%
clear-numN/A
frac-subN/A
div-invN/A
metadata-evalN/A
*-rgt-identityN/A
*-commutativeN/A
associate-/r*N/A
/-lowering-/.f64N/A
Applied egg-rr78.8%
Taylor expanded in x around 0
Simplified51.6%
Final simplification51.6%
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 77.9%
Taylor expanded in x around 0
Simplified50.9%
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 77.9%
Taylor expanded in x around 0
Simplified50.0%
Taylor expanded in x around inf
Simplified10.8%
herbie shell --seed 2024204
(FPCore (x)
:name "Asymptote A"
:precision binary64
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))