
(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 (- 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 81.3%
sub-neg81.3%
+-commutative81.3%
distribute-neg-frac281.3%
neg-sub081.3%
associate-+l-81.3%
neg-sub081.3%
remove-double-neg81.3%
distribute-neg-in81.3%
sub-neg81.3%
distribute-neg-frac281.3%
sub-neg81.3%
+-commutative81.3%
unsub-neg81.3%
sub-neg81.3%
+-commutative81.3%
unsub-neg81.3%
metadata-eval81.3%
Simplified81.3%
sub-neg81.3%
distribute-neg-frac81.3%
metadata-eval81.3%
Applied egg-rr81.3%
Simplified99.6%
associate-/r*99.9%
div-inv99.9%
+-commutative99.9%
Applied egg-rr99.9%
associate-*l/99.9%
frac-2neg99.9%
metadata-eval99.9%
associate-*r/99.9%
metadata-eval99.9%
+-commutative99.9%
distribute-neg-in99.9%
metadata-eval99.9%
sub-neg99.9%
Applied egg-rr99.9%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (if (<= x_m 1.0) 2.0 (/ (/ 2.0 x_m) (- x_m))))
x_m = fabs(x);
double code(double x_m) {
double tmp;
if (x_m <= 1.0) {
tmp = 2.0;
} else {
tmp = (2.0 / x_m) / -x_m;
}
return tmp;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
real(8) :: tmp
if (x_m <= 1.0d0) then
tmp = 2.0d0
else
tmp = (2.0d0 / x_m) / -x_m
end if
code = tmp
end function
x_m = Math.abs(x);
public static double code(double x_m) {
double tmp;
if (x_m <= 1.0) {
tmp = 2.0;
} else {
tmp = (2.0 / x_m) / -x_m;
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): tmp = 0 if x_m <= 1.0: tmp = 2.0 else: tmp = (2.0 / x_m) / -x_m return tmp
x_m = abs(x) function code(x_m) tmp = 0.0 if (x_m <= 1.0) tmp = 2.0; else tmp = Float64(Float64(2.0 / x_m) / Float64(-x_m)); end return tmp end
x_m = abs(x); function tmp_2 = code(x_m) tmp = 0.0; if (x_m <= 1.0) tmp = 2.0; else tmp = (2.0 / x_m) / -x_m; end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := If[LessEqual[x$95$m, 1.0], 2.0, N[(N[(2.0 / x$95$m), $MachinePrecision] / (-x$95$m)), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 1:\\
\;\;\;\;2\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{2}{x\_m}}{-x\_m}\\
\end{array}
\end{array}
if x < 1Initial program 87.9%
sub-neg87.9%
+-commutative87.9%
distribute-neg-frac287.9%
neg-sub087.9%
associate-+l-87.9%
neg-sub087.9%
remove-double-neg87.9%
distribute-neg-in87.9%
sub-neg87.9%
distribute-neg-frac287.9%
sub-neg87.9%
+-commutative87.9%
unsub-neg87.9%
sub-neg87.9%
+-commutative87.9%
unsub-neg87.9%
metadata-eval87.9%
Simplified87.9%
Taylor expanded in x around 0 71.0%
if 1 < x Initial program 60.4%
sub-neg60.4%
+-commutative60.4%
distribute-neg-frac260.4%
neg-sub060.4%
associate-+l-60.4%
neg-sub060.4%
remove-double-neg60.4%
distribute-neg-in60.4%
sub-neg60.4%
distribute-neg-frac260.4%
sub-neg60.4%
+-commutative60.4%
unsub-neg60.4%
sub-neg60.4%
+-commutative60.4%
unsub-neg60.4%
metadata-eval60.4%
Simplified60.4%
sub-neg60.4%
distribute-neg-frac60.4%
metadata-eval60.4%
Applied egg-rr60.4%
Simplified98.5%
Taylor expanded in x around inf 96.9%
div-inv96.9%
frac-2neg96.9%
metadata-eval96.9%
distribute-rgt-neg-in96.9%
+-commutative96.9%
distribute-neg-in96.9%
metadata-eval96.9%
sub-neg96.9%
Applied egg-rr96.9%
associate-*r/96.9%
metadata-eval96.9%
associate-/r*98.3%
Simplified98.3%
Taylor expanded in x around inf 98.6%
neg-mul-198.6%
Simplified98.6%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (/ -2.0 (* (+ 1.0 x_m) (+ x_m -1.0))))
x_m = fabs(x);
double code(double x_m) {
return -2.0 / ((1.0 + x_m) * (x_m + -1.0));
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = (-2.0d0) / ((1.0d0 + x_m) * (x_m + (-1.0d0)))
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return -2.0 / ((1.0 + x_m) * (x_m + -1.0));
}
x_m = math.fabs(x) def code(x_m): return -2.0 / ((1.0 + x_m) * (x_m + -1.0))
x_m = abs(x) function code(x_m) return Float64(-2.0 / Float64(Float64(1.0 + x_m) * Float64(x_m + -1.0))) end
x_m = abs(x); function tmp = code(x_m) tmp = -2.0 / ((1.0 + x_m) * (x_m + -1.0)); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(-2.0 / N[(N[(1.0 + x$95$m), $MachinePrecision] * N[(x$95$m + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{-2}{\left(1 + x\_m\right) \cdot \left(x\_m + -1\right)}
\end{array}
Initial program 81.3%
sub-neg81.3%
+-commutative81.3%
distribute-neg-frac281.3%
neg-sub081.3%
associate-+l-81.3%
neg-sub081.3%
remove-double-neg81.3%
distribute-neg-in81.3%
sub-neg81.3%
distribute-neg-frac281.3%
sub-neg81.3%
+-commutative81.3%
unsub-neg81.3%
sub-neg81.3%
+-commutative81.3%
unsub-neg81.3%
metadata-eval81.3%
Simplified81.3%
sub-neg81.3%
distribute-neg-frac81.3%
metadata-eval81.3%
Applied egg-rr81.3%
Simplified99.6%
Final simplification99.6%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (if (<= x_m 1.0) 2.0 (/ -1.0 x_m)))
x_m = fabs(x);
double code(double x_m) {
double tmp;
if (x_m <= 1.0) {
tmp = 2.0;
} else {
tmp = -1.0 / x_m;
}
return tmp;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
real(8) :: tmp
if (x_m <= 1.0d0) then
tmp = 2.0d0
else
tmp = (-1.0d0) / x_m
end if
code = tmp
end function
x_m = Math.abs(x);
public static double code(double x_m) {
double tmp;
if (x_m <= 1.0) {
tmp = 2.0;
} else {
tmp = -1.0 / x_m;
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): tmp = 0 if x_m <= 1.0: tmp = 2.0 else: tmp = -1.0 / x_m return tmp
x_m = abs(x) function code(x_m) tmp = 0.0 if (x_m <= 1.0) tmp = 2.0; else tmp = Float64(-1.0 / x_m); end return tmp end
x_m = abs(x); function tmp_2 = code(x_m) tmp = 0.0; if (x_m <= 1.0) tmp = 2.0; else tmp = -1.0 / x_m; end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := If[LessEqual[x$95$m, 1.0], 2.0, N[(-1.0 / x$95$m), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 1:\\
\;\;\;\;2\\
\mathbf{else}:\\
\;\;\;\;\frac{-1}{x\_m}\\
\end{array}
\end{array}
if x < 1Initial program 87.9%
sub-neg87.9%
+-commutative87.9%
distribute-neg-frac287.9%
neg-sub087.9%
associate-+l-87.9%
neg-sub087.9%
remove-double-neg87.9%
distribute-neg-in87.9%
sub-neg87.9%
distribute-neg-frac287.9%
sub-neg87.9%
+-commutative87.9%
unsub-neg87.9%
sub-neg87.9%
+-commutative87.9%
unsub-neg87.9%
metadata-eval87.9%
Simplified87.9%
Taylor expanded in x around 0 71.0%
if 1 < x Initial program 60.4%
sub-neg60.4%
+-commutative60.4%
distribute-neg-frac260.4%
neg-sub060.4%
associate-+l-60.4%
neg-sub060.4%
remove-double-neg60.4%
distribute-neg-in60.4%
sub-neg60.4%
distribute-neg-frac260.4%
sub-neg60.4%
+-commutative60.4%
unsub-neg60.4%
sub-neg60.4%
+-commutative60.4%
unsub-neg60.4%
metadata-eval60.4%
Simplified60.4%
Taylor expanded in x around 0 2.7%
Taylor expanded in x around inf 2.7%
Taylor expanded in x around 0 7.0%
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 81.3%
sub-neg81.3%
+-commutative81.3%
distribute-neg-frac281.3%
neg-sub081.3%
associate-+l-81.3%
neg-sub081.3%
remove-double-neg81.3%
distribute-neg-in81.3%
sub-neg81.3%
distribute-neg-frac281.3%
sub-neg81.3%
+-commutative81.3%
unsub-neg81.3%
sub-neg81.3%
+-commutative81.3%
unsub-neg81.3%
metadata-eval81.3%
Simplified81.3%
Taylor expanded in x around 0 54.7%
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 81.3%
sub-neg81.3%
+-commutative81.3%
distribute-neg-frac281.3%
neg-sub081.3%
associate-+l-81.3%
neg-sub081.3%
remove-double-neg81.3%
distribute-neg-in81.3%
sub-neg81.3%
distribute-neg-frac281.3%
sub-neg81.3%
+-commutative81.3%
unsub-neg81.3%
sub-neg81.3%
+-commutative81.3%
unsub-neg81.3%
metadata-eval81.3%
Simplified81.3%
Taylor expanded in x around 0 54.0%
Taylor expanded in x around inf 11.3%
herbie shell --seed 2024130
(FPCore (x)
:name "Asymptote A"
:precision binary64
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))