
(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 11 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 (* (fma 2.0 (pow x -2.0) 2.0) (pow x -3.0)))
double code(double x) {
return fma(2.0, pow(x, -2.0), 2.0) * pow(x, -3.0);
}
function code(x) return Float64(fma(2.0, (x ^ -2.0), 2.0) * (x ^ -3.0)) end
code[x_] := N[(N[(2.0 * N[Power[x, -2.0], $MachinePrecision] + 2.0), $MachinePrecision] * N[Power[x, -3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(2, {x}^{-2}, 2\right) \cdot {x}^{-3}
\end{array}
Initial program 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
Taylor expanded in x around inf 98.7%
associate-*r/98.7%
metadata-eval98.7%
Simplified98.7%
div-inv98.7%
+-commutative98.7%
div-inv98.7%
fma-define98.7%
pow-flip98.7%
metadata-eval98.7%
pow-flip99.4%
metadata-eval99.4%
Applied egg-rr99.4%
(FPCore (x) :precision binary64 (* 2.0 (pow x -3.0)))
double code(double x) {
return 2.0 * pow(x, -3.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 * (x ** (-3.0d0))
end function
public static double code(double x) {
return 2.0 * Math.pow(x, -3.0);
}
def code(x): return 2.0 * math.pow(x, -3.0)
function code(x) return Float64(2.0 * (x ^ -3.0)) end
function tmp = code(x) tmp = 2.0 * (x ^ -3.0); end
code[x_] := N[(2.0 * N[Power[x, -3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot {x}^{-3}
\end{array}
Initial program 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
Taylor expanded in x around inf 98.7%
associate-*r/98.7%
metadata-eval98.7%
Simplified98.7%
div-inv98.7%
+-commutative98.7%
div-inv98.7%
fma-define98.7%
pow-flip98.7%
metadata-eval98.7%
pow-flip99.4%
metadata-eval99.4%
Applied egg-rr99.4%
Taylor expanded in x around inf 99.0%
(FPCore (x) :precision binary64 (+ (/ 1.0 (+ x -1.0)) (+ (/ (+ 2.0 (/ 2.0 x)) (- -1.0 x)) (/ 1.0 (- x -1.0)))))
double code(double x) {
return (1.0 / (x + -1.0)) + (((2.0 + (2.0 / x)) / (-1.0 - x)) + (1.0 / (x - -1.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + (-1.0d0))) + (((2.0d0 + (2.0d0 / x)) / ((-1.0d0) - x)) + (1.0d0 / (x - (-1.0d0))))
end function
public static double code(double x) {
return (1.0 / (x + -1.0)) + (((2.0 + (2.0 / x)) / (-1.0 - x)) + (1.0 / (x - -1.0)));
}
def code(x): return (1.0 / (x + -1.0)) + (((2.0 + (2.0 / x)) / (-1.0 - x)) + (1.0 / (x - -1.0)))
function code(x) return Float64(Float64(1.0 / Float64(x + -1.0)) + Float64(Float64(Float64(2.0 + Float64(2.0 / x)) / Float64(-1.0 - x)) + Float64(1.0 / Float64(x - -1.0)))) end
function tmp = code(x) tmp = (1.0 / (x + -1.0)) + (((2.0 + (2.0 / x)) / (-1.0 - x)) + (1.0 / (x - -1.0))); end
code[x_] := N[(N[(1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(2.0 + N[(2.0 / x), $MachinePrecision]), $MachinePrecision] / N[(-1.0 - x), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(x - -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + -1} + \left(\frac{2 + \frac{2}{x}}{-1 - x} + \frac{1}{x - -1}\right)
\end{array}
Initial program 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
frac-sub14.2%
div-inv14.3%
*-rgt-identity14.3%
fmm-def14.3%
Applied egg-rr14.3%
associate-*r/14.2%
*-rgt-identity14.2%
associate-/r*65.6%
fmm-undef65.6%
div-sub65.6%
*-inverses65.6%
Simplified65.6%
div-sub65.5%
associate-/l*65.5%
Applied egg-rr65.5%
Taylor expanded in x around inf 65.5%
associate-*r/65.5%
metadata-eval65.5%
Simplified65.5%
Final simplification65.5%
(FPCore (x) :precision binary64 (+ (/ 1.0 (+ x -1.0)) (/ (+ -1.0 (+ 2.0 (/ 2.0 x))) (- -1.0 x))))
double code(double x) {
return (1.0 / (x + -1.0)) + ((-1.0 + (2.0 + (2.0 / x))) / (-1.0 - x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + (-1.0d0))) + (((-1.0d0) + (2.0d0 + (2.0d0 / x))) / ((-1.0d0) - x))
end function
public static double code(double x) {
return (1.0 / (x + -1.0)) + ((-1.0 + (2.0 + (2.0 / x))) / (-1.0 - x));
}
def code(x): return (1.0 / (x + -1.0)) + ((-1.0 + (2.0 + (2.0 / x))) / (-1.0 - x))
function code(x) return Float64(Float64(1.0 / Float64(x + -1.0)) + Float64(Float64(-1.0 + Float64(2.0 + Float64(2.0 / x))) / Float64(-1.0 - x))) end
function tmp = code(x) tmp = (1.0 / (x + -1.0)) + ((-1.0 + (2.0 + (2.0 / x))) / (-1.0 - x)); end
code[x_] := N[(N[(1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0 + N[(2.0 + N[(2.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + -1} + \frac{-1 + \left(2 + \frac{2}{x}\right)}{-1 - x}
\end{array}
Initial program 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
frac-sub14.2%
div-inv14.3%
*-rgt-identity14.3%
fmm-def14.3%
Applied egg-rr14.3%
associate-*r/14.2%
*-rgt-identity14.2%
associate-/r*65.6%
fmm-undef65.6%
div-sub65.6%
*-inverses65.6%
Simplified65.6%
Taylor expanded in x around inf 65.6%
associate-*r/65.6%
metadata-eval65.6%
Simplified65.6%
Final simplification65.6%
(FPCore (x) :precision binary64 (+ (/ 1.0 (+ x -1.0)) (- (/ 1.0 (+ x 1.0)) (/ 2.0 x))))
double code(double x) {
return (1.0 / (x + -1.0)) + ((1.0 / (x + 1.0)) - (2.0 / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + (-1.0d0))) + ((1.0d0 / (x + 1.0d0)) - (2.0d0 / x))
end function
public static double code(double x) {
return (1.0 / (x + -1.0)) + ((1.0 / (x + 1.0)) - (2.0 / x));
}
def code(x): return (1.0 / (x + -1.0)) + ((1.0 / (x + 1.0)) - (2.0 / x))
function code(x) return Float64(Float64(1.0 / Float64(x + -1.0)) + Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(2.0 / x))) end
function tmp = code(x) tmp = (1.0 / (x + -1.0)) + ((1.0 / (x + 1.0)) - (2.0 / x)); end
code[x_] := N[(N[(1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(2.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + -1} + \left(\frac{1}{x + 1} - \frac{2}{x}\right)
\end{array}
Initial program 65.5%
Final simplification65.5%
(FPCore (x) :precision binary64 (+ (/ (+ 1.0 (/ 1.0 x)) x) (/ -1.0 x)))
double code(double x) {
return ((1.0 + (1.0 / x)) / x) + (-1.0 / x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((1.0d0 + (1.0d0 / x)) / x) + ((-1.0d0) / x)
end function
public static double code(double x) {
return ((1.0 + (1.0 / x)) / x) + (-1.0 / x);
}
def code(x): return ((1.0 + (1.0 / x)) / x) + (-1.0 / x)
function code(x) return Float64(Float64(Float64(1.0 + Float64(1.0 / x)) / x) + Float64(-1.0 / x)) end
function tmp = code(x) tmp = ((1.0 + (1.0 / x)) / x) + (-1.0 / x); end
code[x_] := N[(N[(N[(1.0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 + \frac{1}{x}}{x} + \frac{-1}{x}
\end{array}
Initial program 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
Taylor expanded in x around inf 64.2%
Taylor expanded in x around inf 64.2%
(FPCore (x) :precision binary64 (/ (- x (+ x -1.0)) (* x x)))
double code(double x) {
return (x - (x + -1.0)) / (x * x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x - (x + (-1.0d0))) / (x * x)
end function
public static double code(double x) {
return (x - (x + -1.0)) / (x * x);
}
def code(x): return (x - (x + -1.0)) / (x * x)
function code(x) return Float64(Float64(x - Float64(x + -1.0)) / Float64(x * x)) end
function tmp = code(x) tmp = (x - (x + -1.0)) / (x * x); end
code[x_] := N[(N[(x - N[(x + -1.0), $MachinePrecision]), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x - \left(x + -1\right)}{x \cdot x}
\end{array}
Initial program 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
Taylor expanded in x around inf 64.2%
frac-add64.2%
*-un-lft-identity64.2%
Applied egg-rr64.2%
Taylor expanded in x around inf 64.2%
Final simplification64.2%
(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 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
Taylor expanded in x around inf 64.2%
(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 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
Taylor expanded in x around inf 64.2%
Taylor expanded in x around inf 64.1%
Final simplification64.1%
(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 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
Taylor expanded in x around inf 64.2%
Taylor expanded in x around 0 5.0%
(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 65.5%
+-commutative65.5%
associate-+r-65.5%
sub-neg65.5%
remove-double-neg65.5%
neg-sub065.5%
associate-+l-65.5%
neg-sub065.5%
distribute-neg-frac265.5%
distribute-frac-neg265.5%
associate-+r+65.5%
+-commutative65.5%
remove-double-neg65.5%
distribute-neg-frac265.5%
sub0-neg65.5%
associate-+l-65.5%
neg-sub065.5%
Simplified65.5%
Taylor expanded in x around 0 5.0%
(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 2024170
(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))))