
(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 8 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 (* x x)) (+ 2.0 (/ 2.0 (pow x 4.0)))) (pow x 3.0)))
double code(double x) {
return ((2.0 / (x * x)) + (2.0 + (2.0 / pow(x, 4.0)))) / pow(x, 3.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((2.0d0 / (x * x)) + (2.0d0 + (2.0d0 / (x ** 4.0d0)))) / (x ** 3.0d0)
end function
public static double code(double x) {
return ((2.0 / (x * x)) + (2.0 + (2.0 / Math.pow(x, 4.0)))) / Math.pow(x, 3.0);
}
def code(x): return ((2.0 / (x * x)) + (2.0 + (2.0 / math.pow(x, 4.0)))) / math.pow(x, 3.0)
function code(x) return Float64(Float64(Float64(2.0 / Float64(x * x)) + Float64(2.0 + Float64(2.0 / (x ^ 4.0)))) / (x ^ 3.0)) end
function tmp = code(x) tmp = ((2.0 / (x * x)) + (2.0 + (2.0 / (x ^ 4.0)))) / (x ^ 3.0); end
code[x_] := N[(N[(N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision] + N[(2.0 + N[(2.0 / N[Power[x, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{2}{x \cdot x} + \left(2 + \frac{2}{{x}^{4}}\right)}{{x}^{3}}
\end{array}
Initial program 70.0%
+-commutative70.0%
associate-+r-70.0%
sub-neg70.0%
remove-double-neg70.0%
neg-sub070.0%
associate-+l-70.0%
neg-sub070.0%
distribute-neg-frac270.0%
distribute-frac-neg270.0%
associate-+r+70.0%
+-commutative70.0%
remove-double-neg70.0%
distribute-neg-frac270.0%
sub0-neg70.0%
associate-+l-70.0%
neg-sub070.0%
Simplified70.0%
Taylor expanded in x around inf 99.1%
associate-+r+99.1%
+-commutative99.1%
associate-+l+99.1%
associate-*r/99.1%
metadata-eval99.1%
Simplified99.1%
unpow299.1%
Applied egg-rr99.1%
(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 70.0%
+-commutative70.0%
associate-+r-70.0%
sub-neg70.0%
remove-double-neg70.0%
neg-sub070.0%
associate-+l-70.0%
neg-sub070.0%
distribute-neg-frac270.0%
distribute-frac-neg270.0%
associate-+r+70.0%
+-commutative70.0%
remove-double-neg70.0%
distribute-neg-frac270.0%
sub0-neg70.0%
associate-+l-70.0%
neg-sub070.0%
Simplified70.0%
Taylor expanded in x around inf 98.3%
div-inv98.3%
pow-flip99.0%
metadata-eval99.0%
Applied egg-rr99.0%
(FPCore (x) :precision binary64 (pow x -3.0))
double code(double x) {
return pow(x, -3.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = x ** (-3.0d0)
end function
public static double code(double x) {
return Math.pow(x, -3.0);
}
def code(x): return math.pow(x, -3.0)
function code(x) return x ^ -3.0 end
function tmp = code(x) tmp = x ^ -3.0; end
code[x_] := N[Power[x, -3.0], $MachinePrecision]
\begin{array}{l}
\\
{x}^{-3}
\end{array}
Initial program 70.0%
+-commutative70.0%
associate-+r-70.0%
sub-neg70.0%
remove-double-neg70.0%
neg-sub070.0%
associate-+l-70.0%
neg-sub070.0%
distribute-neg-frac270.0%
distribute-frac-neg270.0%
associate-+r+70.0%
+-commutative70.0%
remove-double-neg70.0%
distribute-neg-frac270.0%
sub0-neg70.0%
associate-+l-70.0%
neg-sub070.0%
Simplified70.0%
Taylor expanded in x around inf 69.5%
+-commutative69.5%
associate--r+69.5%
unpow269.5%
associate-/r*69.5%
div-sub69.5%
sub-neg69.5%
metadata-eval69.5%
+-commutative69.5%
Simplified69.5%
Taylor expanded in x around inf 69.0%
Taylor expanded in x around inf 72.7%
exp-to-pow39.4%
*-commutative39.4%
exp-neg39.5%
distribute-lft-neg-in39.5%
metadata-eval39.5%
*-commutative39.5%
exp-to-pow72.7%
Simplified72.7%
(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}
Initial program 70.0%
Final simplification70.0%
(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 70.0%
+-commutative70.0%
associate-+r-70.0%
sub-neg70.0%
remove-double-neg70.0%
neg-sub070.0%
associate-+l-70.0%
neg-sub070.0%
distribute-neg-frac270.0%
distribute-frac-neg270.0%
associate-+r+70.0%
+-commutative70.0%
remove-double-neg70.0%
distribute-neg-frac270.0%
sub0-neg70.0%
associate-+l-70.0%
neg-sub070.0%
Simplified70.0%
Taylor expanded in x around inf 68.7%
(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 70.0%
+-commutative70.0%
associate-+r-70.0%
sub-neg70.0%
remove-double-neg70.0%
neg-sub070.0%
associate-+l-70.0%
neg-sub070.0%
distribute-neg-frac270.0%
distribute-frac-neg270.0%
associate-+r+70.0%
+-commutative70.0%
remove-double-neg70.0%
distribute-neg-frac270.0%
sub0-neg70.0%
associate-+l-70.0%
neg-sub070.0%
Simplified70.0%
Taylor expanded in x around 0 3.2%
Taylor expanded in x around inf 3.2%
Taylor expanded in x around 0 5.2%
(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 70.0%
+-commutative70.0%
associate-+r-70.0%
sub-neg70.0%
remove-double-neg70.0%
neg-sub070.0%
associate-+l-70.0%
neg-sub070.0%
distribute-neg-frac270.0%
distribute-frac-neg270.0%
associate-+r+70.0%
+-commutative70.0%
remove-double-neg70.0%
distribute-neg-frac270.0%
sub0-neg70.0%
associate-+l-70.0%
neg-sub070.0%
Simplified70.0%
Taylor expanded in x around 0 5.2%
(FPCore (x) :precision binary64 1.0)
double code(double x) {
return 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0
end function
public static double code(double x) {
return 1.0;
}
def code(x): return 1.0
function code(x) return 1.0 end
function tmp = code(x) tmp = 1.0; end
code[x_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 70.0%
+-commutative70.0%
associate-+r-70.0%
sub-neg70.0%
remove-double-neg70.0%
neg-sub070.0%
associate-+l-70.0%
neg-sub070.0%
distribute-neg-frac270.0%
distribute-frac-neg270.0%
associate-+r+70.0%
+-commutative70.0%
remove-double-neg70.0%
distribute-neg-frac270.0%
sub0-neg70.0%
associate-+l-70.0%
neg-sub070.0%
Simplified70.0%
Taylor expanded in x around 0 3.2%
Taylor expanded in x around inf 3.2%
(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 2024112
(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))))