
(FPCore (x) :precision binary64 (+ (- (/ 1.0 (+ x 1.0)) (/ 2.0 x)) (/ 1.0 (- x 1.0))))
double code(double x) {
return ((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((1.0d0 / (x + 1.0d0)) - (2.0d0 / x)) + (1.0d0 / (x - 1.0d0))
end function
public static double code(double x) {
return ((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x - 1.0));
}
def code(x): return ((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x - 1.0))
function code(x) return Float64(Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(2.0 / x)) + Float64(1.0 / Float64(x - 1.0))) end
function tmp = code(x) tmp = ((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x - 1.0)); end
code[x_] := N[(N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(2.0 / x), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (+ (- (/ 1.0 (+ x 1.0)) (/ 2.0 x)) (/ 1.0 (- x 1.0))))
double code(double x) {
return ((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((1.0d0 / (x + 1.0d0)) - (2.0d0 / x)) + (1.0d0 / (x - 1.0d0))
end function
public static double code(double x) {
return ((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x - 1.0));
}
def code(x): return ((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x - 1.0))
function code(x) return Float64(Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(2.0 / x)) + Float64(1.0 / Float64(x - 1.0))) end
function tmp = code(x) tmp = ((1.0 / (x + 1.0)) - (2.0 / x)) + (1.0 / (x - 1.0)); end
code[x_] := N[(N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(2.0 / x), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1}
\end{array}
(FPCore (x) :precision binary64 (* (+ 2.0 (fma 2.0 (pow x -2.0) (fma 2.0 (pow x -4.0) (/ 2.0 (pow x 6.0))))) (pow x -3.0)))
double code(double x) {
return (2.0 + fma(2.0, pow(x, -2.0), fma(2.0, pow(x, -4.0), (2.0 / pow(x, 6.0))))) * pow(x, -3.0);
}
function code(x) return Float64(Float64(2.0 + fma(2.0, (x ^ -2.0), fma(2.0, (x ^ -4.0), Float64(2.0 / (x ^ 6.0))))) * (x ^ -3.0)) end
code[x_] := N[(N[(2.0 + N[(2.0 * N[Power[x, -2.0], $MachinePrecision] + N[(2.0 * N[Power[x, -4.0], $MachinePrecision] + N[(2.0 / N[Power[x, 6.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Power[x, -3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(2 + \mathsf{fma}\left(2, {x}^{-2}, \mathsf{fma}\left(2, {x}^{-4}, \frac{2}{{x}^{6}}\right)\right)\right) \cdot {x}^{-3}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
Taylor expanded in x around inf 99.0%
associate-*r/99.0%
metadata-eval99.0%
+-commutative99.0%
associate-*r/99.0%
metadata-eval99.0%
Simplified99.0%
div-inv99.1%
div-inv99.1%
fma-define99.1%
pow-flip99.1%
metadata-eval99.1%
div-inv99.1%
fma-define99.1%
pow-flip99.1%
metadata-eval99.1%
pow-flip99.9%
metadata-eval99.9%
Applied egg-rr99.9%
(FPCore (x) :precision binary64 (/ (/ -2.0 (+ x -1.0)) (* x (- -1.0 x))))
double code(double x) {
return (-2.0 / (x + -1.0)) / (x * (-1.0 - x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((-2.0d0) / (x + (-1.0d0))) / (x * ((-1.0d0) - x))
end function
public static double code(double x) {
return (-2.0 / (x + -1.0)) / (x * (-1.0 - x));
}
def code(x): return (-2.0 / (x + -1.0)) / (x * (-1.0 - x))
function code(x) return Float64(Float64(-2.0 / Float64(x + -1.0)) / Float64(x * Float64(-1.0 - x))) end
function tmp = code(x) tmp = (-2.0 / (x + -1.0)) / (x * (-1.0 - x)); end
code[x_] := N[(N[(-2.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] / N[(x * N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{-2}{x + -1}}{x \cdot \left(-1 - x\right)}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
frac-sub16.8%
frac-add16.5%
*-un-lft-identity16.5%
fma-define15.2%
*-rgt-identity15.2%
fma-neg15.2%
Applied egg-rr15.2%
fma-undefine16.5%
+-commutative16.5%
fma-define15.1%
fma-neg15.1%
Simplified15.1%
Taylor expanded in x around 0 99.1%
div-inv99.2%
*-commutative99.2%
associate-*l*99.1%
Applied egg-rr99.1%
associate-*r*99.2%
associate-/r*99.8%
associate-/l*99.8%
associate-*l/99.7%
associate-*r/99.8%
*-rgt-identity99.8%
+-commutative99.8%
Simplified99.8%
Final simplification99.8%
(FPCore (x) :precision binary64 (/ 2.0 (* (- -1.0 x) (* x (- 1.0 x)))))
double code(double x) {
return 2.0 / ((-1.0 - x) * (x * (1.0 - x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 / (((-1.0d0) - x) * (x * (1.0d0 - x)))
end function
public static double code(double x) {
return 2.0 / ((-1.0 - x) * (x * (1.0 - x)));
}
def code(x): return 2.0 / ((-1.0 - x) * (x * (1.0 - x)))
function code(x) return Float64(2.0 / Float64(Float64(-1.0 - x) * Float64(x * Float64(1.0 - x)))) end
function tmp = code(x) tmp = 2.0 / ((-1.0 - x) * (x * (1.0 - x))); end
code[x_] := N[(2.0 / N[(N[(-1.0 - x), $MachinePrecision] * N[(x * N[(1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{\left(-1 - x\right) \cdot \left(x \cdot \left(1 - x\right)\right)}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
frac-sub16.8%
frac-add16.5%
*-un-lft-identity16.5%
fma-define15.2%
*-rgt-identity15.2%
fma-neg15.2%
Applied egg-rr15.2%
fma-undefine16.5%
+-commutative16.5%
fma-define15.1%
fma-neg15.1%
Simplified15.1%
Taylor expanded in x around 0 99.1%
div-inv99.2%
*-commutative99.2%
associate-*l*99.1%
Applied egg-rr99.1%
associate-*r/99.1%
metadata-eval99.1%
metadata-eval99.1%
distribute-neg-frac99.1%
distribute-neg-frac299.1%
associate-*r*99.1%
distribute-rgt-neg-out99.1%
*-commutative99.1%
associate-*l*99.1%
neg-sub099.1%
+-commutative99.1%
associate--r+99.1%
metadata-eval99.1%
Simplified99.1%
(FPCore (x) :precision binary64 (/ -2.0 (* (* x (- -1.0 x)) (+ x -1.0))))
double code(double x) {
return -2.0 / ((x * (-1.0 - x)) * (x + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-2.0d0) / ((x * ((-1.0d0) - x)) * (x + (-1.0d0)))
end function
public static double code(double x) {
return -2.0 / ((x * (-1.0 - x)) * (x + -1.0));
}
def code(x): return -2.0 / ((x * (-1.0 - x)) * (x + -1.0))
function code(x) return Float64(-2.0 / Float64(Float64(x * Float64(-1.0 - x)) * Float64(x + -1.0))) end
function tmp = code(x) tmp = -2.0 / ((x * (-1.0 - x)) * (x + -1.0)); end
code[x_] := N[(-2.0 / N[(N[(x * N[(-1.0 - x), $MachinePrecision]), $MachinePrecision] * N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2}{\left(x \cdot \left(-1 - x\right)\right) \cdot \left(x + -1\right)}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
frac-sub16.8%
frac-add16.5%
*-un-lft-identity16.5%
fma-define15.2%
*-rgt-identity15.2%
fma-neg15.2%
Applied egg-rr15.2%
fma-undefine16.5%
+-commutative16.5%
fma-define15.1%
fma-neg15.1%
Simplified15.1%
Taylor expanded in x around 0 99.1%
Final simplification99.1%
(FPCore (x) :precision binary64 (/ -2.0 (* (+ x -1.0) (* x (- x)))))
double code(double x) {
return -2.0 / ((x + -1.0) * (x * -x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-2.0d0) / ((x + (-1.0d0)) * (x * -x))
end function
public static double code(double x) {
return -2.0 / ((x + -1.0) * (x * -x));
}
def code(x): return -2.0 / ((x + -1.0) * (x * -x))
function code(x) return Float64(-2.0 / Float64(Float64(x + -1.0) * Float64(x * Float64(-x)))) end
function tmp = code(x) tmp = -2.0 / ((x + -1.0) * (x * -x)); end
code[x_] := N[(-2.0 / N[(N[(x + -1.0), $MachinePrecision] * N[(x * (-x)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2}{\left(x + -1\right) \cdot \left(x \cdot \left(-x\right)\right)}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
frac-sub16.8%
frac-add16.5%
*-un-lft-identity16.5%
fma-define15.2%
*-rgt-identity15.2%
fma-neg15.2%
Applied egg-rr15.2%
fma-undefine16.5%
+-commutative16.5%
fma-define15.1%
fma-neg15.1%
Simplified15.1%
Taylor expanded in x around 0 99.1%
Taylor expanded in x around inf 96.7%
neg-mul-196.7%
Simplified96.7%
(FPCore (x) :precision binary64 (/ -2.0 (* x (* x (- -1.0 x)))))
double code(double x) {
return -2.0 / (x * (x * (-1.0 - x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-2.0d0) / (x * (x * ((-1.0d0) - x)))
end function
public static double code(double x) {
return -2.0 / (x * (x * (-1.0 - x)));
}
def code(x): return -2.0 / (x * (x * (-1.0 - x)))
function code(x) return Float64(-2.0 / Float64(x * Float64(x * Float64(-1.0 - x)))) end
function tmp = code(x) tmp = -2.0 / (x * (x * (-1.0 - x))); end
code[x_] := N[(-2.0 / N[(x * N[(x * N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2}{x \cdot \left(x \cdot \left(-1 - x\right)\right)}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
frac-sub16.8%
frac-add16.5%
*-un-lft-identity16.5%
fma-define15.2%
*-rgt-identity15.2%
fma-neg15.2%
Applied egg-rr15.2%
fma-undefine16.5%
+-commutative16.5%
fma-define15.1%
fma-neg15.1%
Simplified15.1%
Taylor expanded in x around 0 99.1%
Taylor expanded in x around inf 96.7%
(FPCore (x) :precision binary64 (+ (/ 1.0 (+ x -1.0)) (/ -1.0 x)))
double code(double x) {
return (1.0 / (x + -1.0)) + (-1.0 / x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + (-1.0d0))) + ((-1.0d0) / x)
end function
public static double code(double x) {
return (1.0 / (x + -1.0)) + (-1.0 / x);
}
def code(x): return (1.0 / (x + -1.0)) + (-1.0 / x)
function code(x) return Float64(Float64(1.0 / Float64(x + -1.0)) + Float64(-1.0 / x)) end
function tmp = code(x) tmp = (1.0 / (x + -1.0)) + (-1.0 / x); end
code[x_] := N[(N[(1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + -1} + \frac{-1}{x}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
Taylor expanded in x around inf 63.3%
(FPCore (x) :precision binary64 (+ (/ -1.0 x) (/ 1.0 x)))
double code(double x) {
return (-1.0 / x) + (1.0 / x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((-1.0d0) / x) + (1.0d0 / x)
end function
public static double code(double x) {
return (-1.0 / x) + (1.0 / x);
}
def code(x): return (-1.0 / x) + (1.0 / x)
function code(x) return Float64(Float64(-1.0 / x) + Float64(1.0 / x)) end
function tmp = code(x) tmp = (-1.0 / x) + (1.0 / x); end
code[x_] := N[(N[(-1.0 / x), $MachinePrecision] + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x} + \frac{1}{x}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
Taylor expanded in x around inf 63.3%
Taylor expanded in x around inf 63.1%
Final simplification63.1%
(FPCore (x) :precision binary64 (/ -1.0 x))
double code(double x) {
return -1.0 / x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / x
end function
public static double code(double x) {
return -1.0 / x;
}
def code(x): return -1.0 / x
function code(x) return Float64(-1.0 / x) end
function tmp = code(x) tmp = -1.0 / x; end
code[x_] := N[(-1.0 / x), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
Taylor expanded in x around inf 63.3%
Taylor expanded in x around 0 4.9%
(FPCore (x) :precision binary64 (/ -2.0 x))
double code(double x) {
return -2.0 / x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-2.0d0) / x
end function
public static double code(double x) {
return -2.0 / x;
}
def code(x): return -2.0 / x
function code(x) return Float64(-2.0 / x) end
function tmp = code(x) tmp = -2.0 / x; end
code[x_] := N[(-2.0 / x), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2}{x}
\end{array}
Initial program 64.8%
+-commutative64.8%
associate-+r-64.7%
sub-neg64.7%
remove-double-neg64.7%
neg-sub064.7%
associate-+l-64.7%
neg-sub064.7%
distribute-neg-frac264.7%
distribute-frac-neg264.7%
associate-+r+64.8%
+-commutative64.8%
remove-double-neg64.8%
distribute-neg-frac264.8%
sub0-neg64.8%
associate-+l-64.8%
neg-sub064.8%
Simplified64.8%
Taylor expanded in x around 0 4.9%
(FPCore (x) :precision binary64 (/ 2.0 (* x (- (* x x) 1.0))))
double code(double x) {
return 2.0 / (x * ((x * x) - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 / (x * ((x * x) - 1.0d0))
end function
public static double code(double x) {
return 2.0 / (x * ((x * x) - 1.0));
}
def code(x): return 2.0 / (x * ((x * x) - 1.0))
function code(x) return Float64(2.0 / Float64(x * Float64(Float64(x * x) - 1.0))) end
function tmp = code(x) tmp = 2.0 / (x * ((x * x) - 1.0)); end
code[x_] := N[(2.0 / N[(x * N[(N[(x * x), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{x \cdot \left(x \cdot x - 1\right)}
\end{array}
herbie shell --seed 2024149
(FPCore (x)
:name "3frac (problem 3.3.3)"
:precision binary64
:pre (> (fabs x) 1.0)
:alt
(! :herbie-platform default (/ 2 (* x (- (* x x) 1))))
(+ (- (/ 1.0 (+ x 1.0)) (/ 2.0 x)) (/ 1.0 (- x 1.0))))