
(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 5 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 (+ (pow x -3.0) (pow x -5.0))))
double code(double x) {
return 2.0 * (pow(x, -3.0) + pow(x, -5.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 * ((x ** (-3.0d0)) + (x ** (-5.0d0)))
end function
public static double code(double x) {
return 2.0 * (Math.pow(x, -3.0) + Math.pow(x, -5.0));
}
def code(x): return 2.0 * (math.pow(x, -3.0) + math.pow(x, -5.0))
function code(x) return Float64(2.0 * Float64((x ^ -3.0) + (x ^ -5.0))) end
function tmp = code(x) tmp = 2.0 * ((x ^ -3.0) + (x ^ -5.0)); end
code[x_] := N[(2.0 * N[(N[Power[x, -3.0], $MachinePrecision] + N[Power[x, -5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \left({x}^{-3} + {x}^{-5}\right)
\end{array}
Initial program 70.0%
+-commutative70.0%
associate-+r-69.9%
sub-neg69.9%
remove-double-neg69.9%
neg-sub069.9%
associate-+l-69.9%
neg-sub069.9%
distribute-neg-frac269.9%
distribute-frac-neg269.9%
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 99.5%
associate-*r/99.5%
metadata-eval99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
*-un-lft-identity99.5%
div-inv99.5%
fma-define99.5%
pow-flip99.8%
metadata-eval99.8%
div-inv99.8%
pow-flip99.8%
metadata-eval99.8%
Applied egg-rr99.8%
*-lft-identity99.8%
fma-undefine99.8%
distribute-lft-out99.8%
Simplified99.8%
Final simplification99.8%
(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-69.9%
sub-neg69.9%
remove-double-neg69.9%
neg-sub069.9%
associate-+l-69.9%
neg-sub069.9%
distribute-neg-frac269.9%
distribute-frac-neg269.9%
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 99.2%
div-inv99.2%
pow-flip99.5%
metadata-eval99.5%
Applied egg-rr99.5%
Final simplification99.5%
(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-69.9%
sub-neg69.9%
remove-double-neg69.9%
neg-sub069.9%
associate-+l-69.9%
neg-sub069.9%
distribute-neg-frac269.9%
distribute-frac-neg269.9%
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 69.4%
Final simplification69.4%
(FPCore (x) :precision binary64 0.0)
double code(double x) {
return 0.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.0d0
end function
public static double code(double x) {
return 0.0;
}
def code(x): return 0.0
function code(x) return 0.0 end
function tmp = code(x) tmp = 0.0; end
code[x_] := 0.0
\begin{array}{l}
\\
0
\end{array}
Initial program 70.0%
+-commutative70.0%
associate-+r-69.9%
sub-neg69.9%
remove-double-neg69.9%
neg-sub069.9%
associate-+l-69.9%
neg-sub069.9%
distribute-neg-frac269.9%
distribute-frac-neg269.9%
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 69.4%
frac-add69.4%
*-un-lft-identity69.4%
*-commutative69.4%
neg-mul-169.4%
+-commutative69.4%
distribute-neg-in69.4%
metadata-eval69.4%
*-commutative69.4%
Applied egg-rr69.4%
Applied egg-rr69.1%
Final simplification69.1%
(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 2024040
(FPCore (x)
:name "3frac (problem 3.3.3)"
:precision binary64
:pre (> (fabs x) 1.0)
:herbie-target
(/ 2.0 (* x (- (* x x) 1.0)))
(+ (- (/ 1.0 (+ x 1.0)) (/ 2.0 x)) (/ 1.0 (- x 1.0))))