
(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 80.5%
sub-neg80.5%
+-commutative80.5%
distribute-neg-frac280.5%
neg-sub080.5%
associate-+l-80.5%
neg-sub080.5%
remove-double-neg80.5%
distribute-neg-in80.5%
sub-neg80.5%
distribute-neg-frac280.5%
sub-neg80.5%
+-commutative80.5%
unsub-neg80.5%
sub-neg80.5%
+-commutative80.5%
unsub-neg80.5%
metadata-eval80.5%
Simplified80.5%
sub-neg80.5%
distribute-neg-frac80.5%
metadata-eval80.5%
Applied egg-rr80.5%
Simplified99.4%
add-cube-cbrt97.8%
pow397.5%
metadata-eval97.5%
sub-neg97.5%
difference-of-sqr-197.5%
fma-neg97.5%
metadata-eval97.5%
Applied egg-rr97.5%
rem-cube-cbrt99.4%
fma-undefine99.4%
difference-of-sqr--199.4%
add-sqr-sqrt74.9%
sub-neg74.9%
metadata-eval74.9%
unpow274.9%
frac-2neg74.9%
metadata-eval74.9%
distribute-lft-neg-in74.9%
mul-1-neg74.9%
unpow274.9%
add-sqr-sqrt99.4%
+-commutative99.4%
distribute-lft-in99.4%
metadata-eval99.4%
neg-mul-199.4%
sub-neg99.4%
+-commutative99.4%
flip-+99.4%
sub-neg99.4%
metadata-eval99.4%
neg-mul-199.4%
distribute-lft-in99.4%
+-commutative99.4%
add-sqr-sqrt74.9%
unpow274.9%
Applied egg-rr99.9%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (if (<= x_m 0.75) 2.0 (/ (/ -2.0 x_m) (+ -1.0 x_m))))
x_m = fabs(x);
double code(double x_m) {
double tmp;
if (x_m <= 0.75) {
tmp = 2.0;
} else {
tmp = (-2.0 / x_m) / (-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 <= 0.75d0) then
tmp = 2.0d0
else
tmp = ((-2.0d0) / x_m) / ((-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 <= 0.75) {
tmp = 2.0;
} else {
tmp = (-2.0 / x_m) / (-1.0 + x_m);
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): tmp = 0 if x_m <= 0.75: tmp = 2.0 else: tmp = (-2.0 / x_m) / (-1.0 + x_m) return tmp
x_m = abs(x) function code(x_m) tmp = 0.0 if (x_m <= 0.75) tmp = 2.0; else tmp = Float64(Float64(-2.0 / x_m) / 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 <= 0.75) tmp = 2.0; else tmp = (-2.0 / x_m) / (-1.0 + x_m); end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := If[LessEqual[x$95$m, 0.75], 2.0, N[(N[(-2.0 / x$95$m), $MachinePrecision] / N[(-1.0 + x$95$m), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.75:\\
\;\;\;\;2\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{-2}{x\_m}}{-1 + x\_m}\\
\end{array}
\end{array}
if x < 0.75Initial program 87.0%
sub-neg87.0%
+-commutative87.0%
distribute-neg-frac287.0%
neg-sub087.0%
associate-+l-87.0%
neg-sub087.0%
remove-double-neg87.0%
distribute-neg-in87.0%
sub-neg87.0%
distribute-neg-frac287.0%
sub-neg87.0%
+-commutative87.0%
unsub-neg87.0%
sub-neg87.0%
+-commutative87.0%
unsub-neg87.0%
metadata-eval87.0%
Simplified87.0%
Taylor expanded in x around 0 66.0%
if 0.75 < x Initial program 64.2%
sub-neg64.2%
+-commutative64.2%
distribute-neg-frac264.2%
neg-sub064.2%
associate-+l-64.2%
neg-sub064.2%
remove-double-neg64.2%
distribute-neg-in64.2%
sub-neg64.2%
distribute-neg-frac264.2%
sub-neg64.2%
+-commutative64.2%
unsub-neg64.2%
sub-neg64.2%
+-commutative64.2%
unsub-neg64.2%
metadata-eval64.2%
Simplified64.2%
sub-neg64.2%
distribute-neg-frac64.2%
metadata-eval64.2%
Applied egg-rr64.2%
Simplified98.6%
add-sqr-sqrt98.4%
pow298.4%
Applied egg-rr98.4%
Taylor expanded in x around inf 94.6%
unpow294.6%
add-sqr-sqrt94.8%
associate-/r*96.0%
div-inv95.8%
+-commutative95.8%
Applied egg-rr95.8%
associate-*r/96.0%
*-rgt-identity96.0%
+-commutative96.0%
Simplified96.0%
Final simplification74.5%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (if (<= x_m 0.75) 2.0 (/ -2.0 (* x_m (+ -1.0 x_m)))))
x_m = fabs(x);
double code(double x_m) {
double tmp;
if (x_m <= 0.75) {
tmp = 2.0;
} else {
tmp = -2.0 / (x_m * (-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 <= 0.75d0) then
tmp = 2.0d0
else
tmp = (-2.0d0) / (x_m * ((-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 <= 0.75) {
tmp = 2.0;
} else {
tmp = -2.0 / (x_m * (-1.0 + x_m));
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): tmp = 0 if x_m <= 0.75: tmp = 2.0 else: tmp = -2.0 / (x_m * (-1.0 + x_m)) return tmp
x_m = abs(x) function code(x_m) tmp = 0.0 if (x_m <= 0.75) tmp = 2.0; else tmp = Float64(-2.0 / Float64(x_m * 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 <= 0.75) tmp = 2.0; else tmp = -2.0 / (x_m * (-1.0 + x_m)); end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := If[LessEqual[x$95$m, 0.75], 2.0, N[(-2.0 / N[(x$95$m * N[(-1.0 + x$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.75:\\
\;\;\;\;2\\
\mathbf{else}:\\
\;\;\;\;\frac{-2}{x\_m \cdot \left(-1 + x\_m\right)}\\
\end{array}
\end{array}
if x < 0.75Initial program 87.0%
sub-neg87.0%
+-commutative87.0%
distribute-neg-frac287.0%
neg-sub087.0%
associate-+l-87.0%
neg-sub087.0%
remove-double-neg87.0%
distribute-neg-in87.0%
sub-neg87.0%
distribute-neg-frac287.0%
sub-neg87.0%
+-commutative87.0%
unsub-neg87.0%
sub-neg87.0%
+-commutative87.0%
unsub-neg87.0%
metadata-eval87.0%
Simplified87.0%
Taylor expanded in x around 0 66.0%
if 0.75 < x Initial program 64.2%
sub-neg64.2%
+-commutative64.2%
distribute-neg-frac264.2%
neg-sub064.2%
associate-+l-64.2%
neg-sub064.2%
remove-double-neg64.2%
distribute-neg-in64.2%
sub-neg64.2%
distribute-neg-frac264.2%
sub-neg64.2%
+-commutative64.2%
unsub-neg64.2%
sub-neg64.2%
+-commutative64.2%
unsub-neg64.2%
metadata-eval64.2%
Simplified64.2%
sub-neg64.2%
distribute-neg-frac64.2%
metadata-eval64.2%
Applied egg-rr64.2%
Simplified98.6%
Taylor expanded in x around inf 94.8%
Final simplification74.2%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (/ -2.0 (* (+ x_m 1.0) (+ -1.0 x_m))))
x_m = fabs(x);
double code(double x_m) {
return -2.0 / ((x_m + 1.0) * (-1.0 + x_m));
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = (-2.0d0) / ((x_m + 1.0d0) * ((-1.0d0) + x_m))
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return -2.0 / ((x_m + 1.0) * (-1.0 + x_m));
}
x_m = math.fabs(x) def code(x_m): return -2.0 / ((x_m + 1.0) * (-1.0 + x_m))
x_m = abs(x) function code(x_m) return Float64(-2.0 / Float64(Float64(x_m + 1.0) * Float64(-1.0 + x_m))) end
x_m = abs(x); function tmp = code(x_m) tmp = -2.0 / ((x_m + 1.0) * (-1.0 + x_m)); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(-2.0 / N[(N[(x$95$m + 1.0), $MachinePrecision] * N[(-1.0 + x$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{-2}{\left(x\_m + 1\right) \cdot \left(-1 + x\_m\right)}
\end{array}
Initial program 80.5%
sub-neg80.5%
+-commutative80.5%
distribute-neg-frac280.5%
neg-sub080.5%
associate-+l-80.5%
neg-sub080.5%
remove-double-neg80.5%
distribute-neg-in80.5%
sub-neg80.5%
distribute-neg-frac280.5%
sub-neg80.5%
+-commutative80.5%
unsub-neg80.5%
sub-neg80.5%
+-commutative80.5%
unsub-neg80.5%
metadata-eval80.5%
Simplified80.5%
sub-neg80.5%
distribute-neg-frac80.5%
metadata-eval80.5%
Applied egg-rr80.5%
Simplified99.4%
Final simplification99.4%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (if (<= x_m 1.0) 2.0 (/ -2.0 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;
}
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
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;
}
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 return tmp
x_m = abs(x) function code(x_m) tmp = 0.0 if (x_m <= 1.0) tmp = 2.0; else tmp = Float64(-2.0 / 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 = -2.0 / 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[(-2.0 / 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{-2}{x\_m}\\
\end{array}
\end{array}
if x < 1Initial program 87.0%
sub-neg87.0%
+-commutative87.0%
distribute-neg-frac287.0%
neg-sub087.0%
associate-+l-87.0%
neg-sub087.0%
remove-double-neg87.0%
distribute-neg-in87.0%
sub-neg87.0%
distribute-neg-frac287.0%
sub-neg87.0%
+-commutative87.0%
unsub-neg87.0%
sub-neg87.0%
+-commutative87.0%
unsub-neg87.0%
metadata-eval87.0%
Simplified87.0%
Taylor expanded in x around 0 66.0%
if 1 < x Initial program 64.2%
sub-neg64.2%
+-commutative64.2%
distribute-neg-frac264.2%
neg-sub064.2%
associate-+l-64.2%
neg-sub064.2%
remove-double-neg64.2%
distribute-neg-in64.2%
sub-neg64.2%
distribute-neg-frac264.2%
sub-neg64.2%
+-commutative64.2%
unsub-neg64.2%
sub-neg64.2%
+-commutative64.2%
unsub-neg64.2%
metadata-eval64.2%
Simplified64.2%
frac-sub66.7%
*-rgt-identity66.7%
metadata-eval66.7%
div-inv66.7%
associate-/r*66.7%
metadata-eval66.7%
div-inv66.7%
*-un-lft-identity66.7%
associate--l-71.0%
div-inv71.0%
metadata-eval71.0%
*-rgt-identity71.0%
div-inv71.0%
metadata-eval71.0%
*-rgt-identity71.0%
Applied egg-rr71.0%
Taylor expanded in x around inf 96.0%
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 80.5%
sub-neg80.5%
+-commutative80.5%
distribute-neg-frac280.5%
neg-sub080.5%
associate-+l-80.5%
neg-sub080.5%
remove-double-neg80.5%
distribute-neg-in80.5%
sub-neg80.5%
distribute-neg-frac280.5%
sub-neg80.5%
+-commutative80.5%
unsub-neg80.5%
sub-neg80.5%
+-commutative80.5%
unsub-neg80.5%
metadata-eval80.5%
Simplified80.5%
Taylor expanded in x around 0 47.9%
herbie shell --seed 2024141
(FPCore (x)
:name "Asymptote A"
:precision binary64
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))