
(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 (* (* (fma 2.0 (pow x -2.0) 2.0) (+ 1.0 (pow x -4.0))) (pow x -3.0)))
double code(double x) {
return (fma(2.0, pow(x, -2.0), 2.0) * (1.0 + pow(x, -4.0))) * pow(x, -3.0);
}
function code(x) return Float64(Float64(fma(2.0, (x ^ -2.0), 2.0) * Float64(1.0 + (x ^ -4.0))) * (x ^ -3.0)) end
code[x_] := N[(N[(N[(2.0 * N[Power[x, -2.0], $MachinePrecision] + 2.0), $MachinePrecision] * N[(1.0 + N[Power[x, -4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Power[x, -3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\mathsf{fma}\left(2, {x}^{-2}, 2\right) \cdot \left(1 + {x}^{-4}\right)\right) \cdot {x}^{-3}
\end{array}
Initial program 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around -inf 98.9%
mul-1-neg98.9%
distribute-neg-frac98.9%
Simplified98.9%
div-inv98.9%
div-inv98.9%
fma-define98.9%
+-commutative98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
pow-flip98.9%
metadata-eval98.9%
+-commutative98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
pow-flip99.7%
metadata-eval99.7%
Applied egg-rr99.7%
fma-undefine99.7%
+-commutative99.7%
*-lft-identity99.7%
*-commutative99.7%
distribute-rgt-out99.7%
Simplified99.7%
(FPCore (x) :precision binary64 (/ (* (+ 1.0 (pow x -4.0)) (fma 2.0 (* (/ 1.0 x) (/ 1.0 x)) 2.0)) (pow x 3.0)))
double code(double x) {
return ((1.0 + pow(x, -4.0)) * fma(2.0, ((1.0 / x) * (1.0 / x)), 2.0)) / pow(x, 3.0);
}
function code(x) return Float64(Float64(Float64(1.0 + (x ^ -4.0)) * fma(2.0, Float64(Float64(1.0 / x) * Float64(1.0 / x)), 2.0)) / (x ^ 3.0)) end
code[x_] := N[(N[(N[(1.0 + N[Power[x, -4.0], $MachinePrecision]), $MachinePrecision] * N[(2.0 * N[(N[(1.0 / x), $MachinePrecision] * N[(1.0 / x), $MachinePrecision]), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] / N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(1 + {x}^{-4}\right) \cdot \mathsf{fma}\left(2, \frac{1}{x} \cdot \frac{1}{x}, 2\right)}{{x}^{3}}
\end{array}
Initial program 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around -inf 98.9%
mul-1-neg98.9%
distribute-neg-frac98.9%
Simplified98.9%
add-cube-cbrt98.4%
Applied egg-rr98.8%
unpow298.8%
unpow398.8%
cube-div98.1%
rem-cube-cbrt98.9%
fma-undefine98.9%
+-commutative98.9%
*-lft-identity98.9%
*-commutative98.9%
distribute-rgt-out98.9%
Simplified98.9%
metadata-eval98.9%
pow-prod-up98.9%
inv-pow98.9%
inv-pow98.9%
Applied egg-rr98.9%
Final simplification98.9%
(FPCore (x) :precision binary64 (/ (+ 2.0 (+ (/ 2.0 (pow x 2.0)) (/ 2.0 (pow x 4.0)))) (pow x 3.0)))
double code(double x) {
return (2.0 + ((2.0 / pow(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 + ((2.0d0 / (x ** 2.0d0)) + (2.0d0 / (x ** 4.0d0)))) / (x ** 3.0d0)
end function
public static double code(double x) {
return (2.0 + ((2.0 / Math.pow(x, 2.0)) + (2.0 / Math.pow(x, 4.0)))) / Math.pow(x, 3.0);
}
def code(x): return (2.0 + ((2.0 / math.pow(x, 2.0)) + (2.0 / math.pow(x, 4.0)))) / math.pow(x, 3.0)
function code(x) return Float64(Float64(2.0 + Float64(Float64(2.0 / (x ^ 2.0)) + Float64(2.0 / (x ^ 4.0)))) / (x ^ 3.0)) end
function tmp = code(x) tmp = (2.0 + ((2.0 / (x ^ 2.0)) + (2.0 / (x ^ 4.0)))) / (x ^ 3.0); end
code[x_] := N[(N[(2.0 + N[(N[(2.0 / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision] + N[(2.0 / N[Power[x, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2 + \left(\frac{2}{{x}^{2}} + \frac{2}{{x}^{4}}\right)}{{x}^{3}}
\end{array}
Initial program 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around inf 98.7%
associate-*r/98.7%
metadata-eval98.7%
Simplified98.7%
(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 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around -inf 98.9%
mul-1-neg98.9%
distribute-neg-frac98.9%
Simplified98.9%
div-inv98.9%
div-inv98.9%
fma-define98.9%
+-commutative98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
pow-flip98.9%
metadata-eval98.9%
+-commutative98.9%
div-inv98.9%
fma-define98.9%
pow-flip98.9%
metadata-eval98.9%
pow-flip99.7%
metadata-eval99.7%
Applied egg-rr99.7%
fma-undefine99.7%
+-commutative99.7%
*-lft-identity99.7%
*-commutative99.7%
distribute-rgt-out99.7%
Simplified99.7%
Taylor expanded in x around inf 98.6%
(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 74.7%
Final simplification74.7%
(FPCore (x) :precision binary64 (+ (/ 1.0 (+ x -1.0)) (/ (+ -1.0 (/ -1.0 x)) x)))
double code(double x) {
return (1.0 / (x + -1.0)) + ((-1.0 + (-1.0 / x)) / x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + (-1.0d0))) + (((-1.0d0) + ((-1.0d0) / x)) / x)
end function
public static double code(double x) {
return (1.0 / (x + -1.0)) + ((-1.0 + (-1.0 / x)) / x);
}
def code(x): return (1.0 / (x + -1.0)) + ((-1.0 + (-1.0 / x)) / x)
function code(x) return Float64(Float64(1.0 / Float64(x + -1.0)) + Float64(Float64(-1.0 + Float64(-1.0 / x)) / x)) end
function tmp = code(x) tmp = (1.0 / (x + -1.0)) + ((-1.0 + (-1.0 / x)) / x); end
code[x_] := N[(N[(1.0 / N[(x + -1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + -1} + \frac{-1 + \frac{-1}{x}}{x}
\end{array}
Initial program 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around inf 73.3%
associate-*r/73.3%
neg-mul-173.3%
distribute-neg-in73.3%
metadata-eval73.3%
distribute-neg-frac73.3%
metadata-eval73.3%
Simplified73.3%
(FPCore (x) :precision binary64 (/ (- x (+ x -1.0)) (* x (+ x -1.0))))
double code(double x) {
return (x - (x + -1.0)) / (x * (x + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x - (x + (-1.0d0))) / (x * (x + (-1.0d0)))
end function
public static double code(double x) {
return (x - (x + -1.0)) / (x * (x + -1.0));
}
def code(x): return (x - (x + -1.0)) / (x * (x + -1.0))
function code(x) return Float64(Float64(x - Float64(x + -1.0)) / Float64(x * Float64(x + -1.0))) end
function tmp = code(x) tmp = (x - (x + -1.0)) / (x * (x + -1.0)); end
code[x_] := N[(N[(x - N[(x + -1.0), $MachinePrecision]), $MachinePrecision] / N[(x * N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x - \left(x + -1\right)}{x \cdot \left(x + -1\right)}
\end{array}
Initial program 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around inf 73.0%
frac-add73.1%
*-un-lft-identity73.1%
Applied egg-rr73.1%
*-commutative73.1%
neg-mul-173.1%
unsub-neg73.1%
*-commutative73.1%
Simplified73.1%
(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 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around inf 73.0%
(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 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around inf 73.0%
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 74.7%
+-commutative74.7%
associate-+r-74.7%
sub-neg74.7%
remove-double-neg74.7%
neg-sub074.7%
associate-+l-74.7%
neg-sub074.7%
distribute-neg-frac274.7%
distribute-frac-neg274.7%
associate-+r+74.7%
+-commutative74.7%
remove-double-neg74.7%
distribute-neg-frac274.7%
sub0-neg74.7%
associate-+l-74.7%
neg-sub074.7%
Simplified74.7%
Taylor expanded in x around 0 5.2%
(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 2024086
(FPCore (x)
:name "3frac (problem 3.3.3)"
:precision binary64
:pre (> (fabs x) 1.0)
:alt
(/ 2.0 (* x (- (* x x) 1.0)))
(+ (- (/ 1.0 (+ x 1.0)) (/ 2.0 x)) (/ 1.0 (- x 1.0))))