
(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) (* 2.0 (+ (pow x -6.0) (pow x -4.0))))) (pow x -3.0)))
double code(double x) {
return (2.0 + fma(2.0, pow(x, -2.0), (2.0 * (pow(x, -6.0) + pow(x, -4.0))))) * pow(x, -3.0);
}
function code(x) return Float64(Float64(2.0 + fma(2.0, (x ^ -2.0), Float64(2.0 * Float64((x ^ -6.0) + (x ^ -4.0))))) * (x ^ -3.0)) end
code[x_] := N[(N[(2.0 + N[(2.0 * N[Power[x, -2.0], $MachinePrecision] + N[(2.0 * N[(N[Power[x, -6.0], $MachinePrecision] + N[Power[x, -4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Power[x, -3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(2 + \mathsf{fma}\left(2, {x}^{-2}, 2 \cdot \left({x}^{-6} + {x}^{-4}\right)\right)\right) \cdot {x}^{-3}
\end{array}
Initial program 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
Taylor expanded in x around inf 98.9%
associate-*r/98.9%
metadata-eval98.9%
+-commutative98.9%
associate-*r/98.9%
metadata-eval98.9%
Simplified98.9%
div-inv98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
+-commutative98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
div-inv98.9%
pow-flip98.9%
metadata-eval98.9%
pow-flip99.9%
metadata-eval99.9%
Applied egg-rr99.9%
*-lft-identity99.9%
*-lft-identity99.9%
fma-undefine99.9%
distribute-lft-out99.9%
Simplified99.9%
(FPCore (x) :precision binary64 (* (pow x -3.0) (+ 2.0 (/ (+ 2.0 (/ 2.0 (pow x 2.0))) (pow x 2.0)))))
double code(double x) {
return pow(x, -3.0) * (2.0 + ((2.0 + (2.0 / pow(x, 2.0))) / pow(x, 2.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x ** (-3.0d0)) * (2.0d0 + ((2.0d0 + (2.0d0 / (x ** 2.0d0))) / (x ** 2.0d0)))
end function
public static double code(double x) {
return Math.pow(x, -3.0) * (2.0 + ((2.0 + (2.0 / Math.pow(x, 2.0))) / Math.pow(x, 2.0)));
}
def code(x): return math.pow(x, -3.0) * (2.0 + ((2.0 + (2.0 / math.pow(x, 2.0))) / math.pow(x, 2.0)))
function code(x) return Float64((x ^ -3.0) * Float64(2.0 + Float64(Float64(2.0 + Float64(2.0 / (x ^ 2.0))) / (x ^ 2.0)))) end
function tmp = code(x) tmp = (x ^ -3.0) * (2.0 + ((2.0 + (2.0 / (x ^ 2.0))) / (x ^ 2.0))); end
code[x_] := N[(N[Power[x, -3.0], $MachinePrecision] * N[(2.0 + N[(N[(2.0 + N[(2.0 / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{x}^{-3} \cdot \left(2 + \frac{2 + \frac{2}{{x}^{2}}}{{x}^{2}}\right)
\end{array}
Initial program 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
Taylor expanded in x around inf 98.9%
associate-*r/98.9%
metadata-eval98.9%
+-commutative98.9%
associate-*r/98.9%
metadata-eval98.9%
Simplified98.9%
div-inv98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
+-commutative98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
div-inv98.9%
pow-flip98.9%
metadata-eval98.9%
pow-flip99.9%
metadata-eval99.9%
Applied egg-rr99.9%
*-lft-identity99.9%
*-lft-identity99.9%
fma-undefine99.9%
distribute-lft-out99.9%
Simplified99.9%
Taylor expanded in x around inf 99.8%
associate-*r/99.8%
metadata-eval99.8%
Simplified99.8%
Final simplification99.8%
(FPCore (x) :precision binary64 (/ -2.0 (* x (- 1.0 (pow x 2.0)))))
double code(double x) {
return -2.0 / (x * (1.0 - pow(x, 2.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-2.0d0) / (x * (1.0d0 - (x ** 2.0d0)))
end function
public static double code(double x) {
return -2.0 / (x * (1.0 - Math.pow(x, 2.0)));
}
def code(x): return -2.0 / (x * (1.0 - math.pow(x, 2.0)))
function code(x) return Float64(-2.0 / Float64(x * Float64(1.0 - (x ^ 2.0)))) end
function tmp = code(x) tmp = -2.0 / (x * (1.0 - (x ^ 2.0))); end
code[x_] := N[(-2.0 / N[(x * N[(1.0 - N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2}{x \cdot \left(1 - {x}^{2}\right)}
\end{array}
Initial program 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
frac-sub19.4%
frac-add21.0%
*-un-lft-identity21.0%
fma-define20.0%
*-rgt-identity20.0%
fma-neg20.0%
Applied egg-rr20.0%
Simplified20.0%
Taylor expanded in x around 0 98.9%
(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 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
Taylor expanded in x around inf 98.9%
associate-*r/98.9%
metadata-eval98.9%
+-commutative98.9%
associate-*r/98.9%
metadata-eval98.9%
Simplified98.9%
div-inv98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
+-commutative98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
div-inv98.9%
pow-flip98.9%
metadata-eval98.9%
pow-flip99.9%
metadata-eval99.9%
Applied egg-rr99.9%
*-lft-identity99.9%
*-lft-identity99.9%
fma-undefine99.9%
distribute-lft-out99.9%
Simplified99.9%
Taylor expanded in x around inf 98.6%
(FPCore (x) :precision binary64 (/ (/ 1.0 x) (* x (+ x -1.0))))
double code(double x) {
return (1.0 / x) / (x * (x + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / x) / (x * (x + (-1.0d0)))
end function
public static double code(double x) {
return (1.0 / x) / (x * (x + -1.0));
}
def code(x): return (1.0 / x) / (x * (x + -1.0))
function code(x) return Float64(Float64(1.0 / x) / Float64(x * Float64(x + -1.0))) end
function tmp = code(x) tmp = (1.0 / x) / (x * (x + -1.0)); end
code[x_] := N[(N[(1.0 / x), $MachinePrecision] / N[(x * N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{1}{x}}{x \cdot \left(x + -1\right)}
\end{array}
Initial program 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
clear-num70.6%
frac-sub19.4%
*-un-lft-identity19.4%
div-inv19.4%
metadata-eval19.4%
div-inv19.4%
metadata-eval19.4%
Applied egg-rr19.4%
sub-neg19.4%
sub-neg19.4%
distribute-rgt-neg-in19.4%
metadata-eval19.4%
associate-+l+19.4%
neg-mul-119.4%
*-commutative19.4%
associate-*l*19.4%
distribute-lft-out19.4%
metadata-eval19.4%
metadata-eval19.4%
associate-*l*19.4%
sub-neg19.4%
+-commutative19.4%
distribute-rgt-in19.4%
distribute-lft-neg-in19.4%
distribute-rgt-neg-in19.4%
metadata-eval19.4%
metadata-eval19.4%
Simplified19.4%
Taylor expanded in x around inf 69.2%
associate-*r/69.2%
neg-mul-169.2%
distribute-neg-in69.2%
metadata-eval69.2%
sub-neg69.2%
Simplified69.2%
frac-add69.2%
*-un-lft-identity69.2%
Applied egg-rr69.2%
Taylor expanded in x around 0 73.1%
Final simplification73.1%
(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 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
Taylor expanded in x around inf 68.9%
(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 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
Taylor expanded in x around inf 68.9%
Taylor expanded in x around inf 68.7%
(FPCore (x) :precision binary64 (/ (/ 1.0 x) x))
double code(double x) {
return (1.0 / x) / x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / x) / x
end function
public static double code(double x) {
return (1.0 / x) / x;
}
def code(x): return (1.0 / x) / x
function code(x) return Float64(Float64(1.0 / x) / x) end
function tmp = code(x) tmp = (1.0 / x) / x; end
code[x_] := N[(N[(1.0 / x), $MachinePrecision] / x), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{1}{x}}{x}
\end{array}
Initial program 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
Taylor expanded in x around inf 68.9%
Taylor expanded in x around inf 53.5%
unpow253.5%
associate-/l/51.8%
rem-exp-log26.2%
exp-neg26.2%
rem-exp-log26.2%
exp-diff26.2%
sub-neg26.2%
neg-mul-126.2%
neg-mul-126.2%
distribute-rgt-out26.2%
metadata-eval26.2%
exp-to-pow51.8%
Simplified51.8%
metadata-eval51.8%
pow-div51.8%
inv-pow51.8%
pow151.8%
Applied egg-rr51.8%
(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 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
Taylor expanded in x around inf 68.9%
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 70.6%
+-commutative70.6%
associate-+r-70.6%
sub-neg70.6%
remove-double-neg70.6%
neg-sub070.6%
associate-+l-70.6%
neg-sub070.6%
distribute-neg-frac270.6%
distribute-frac-neg270.6%
associate-+r+70.6%
+-commutative70.6%
remove-double-neg70.6%
distribute-neg-frac270.6%
sub0-neg70.6%
associate-+l-70.6%
neg-sub070.6%
Simplified70.6%
Taylor expanded in x around 0 5.1%
(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 2024137
(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))))