
(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 9 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 72.4%
+-commutative72.4%
associate-+r-72.4%
sub-neg72.4%
remove-double-neg72.4%
neg-sub072.4%
associate-+l-72.4%
neg-sub072.4%
distribute-neg-frac272.4%
distribute-frac-neg272.4%
associate-+r+72.4%
+-commutative72.4%
remove-double-neg72.4%
distribute-neg-frac272.4%
sub0-neg72.4%
associate-+l-72.4%
neg-sub072.4%
Simplified72.4%
Taylor expanded in x around inf 98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
div-inv98.4%
+-commutative98.4%
div-inv98.4%
fma-define98.4%
pow-flip98.4%
metadata-eval98.4%
pow-flip100.0%
metadata-eval100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (pow (/ (cbrt 2.0) x) 3.0))
double code(double x) {
return pow((cbrt(2.0) / x), 3.0);
}
public static double code(double x) {
return Math.pow((Math.cbrt(2.0) / x), 3.0);
}
function code(x) return Float64(cbrt(2.0) / x) ^ 3.0 end
code[x_] := N[Power[N[(N[Power[2.0, 1/3], $MachinePrecision] / x), $MachinePrecision], 3.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{\sqrt[3]{2}}{x}\right)}^{3}
\end{array}
Initial program 72.4%
+-commutative72.4%
associate-+r-72.4%
sub-neg72.4%
remove-double-neg72.4%
neg-sub072.4%
associate-+l-72.4%
neg-sub072.4%
distribute-neg-frac272.4%
distribute-frac-neg272.4%
associate-+r+72.4%
+-commutative72.4%
remove-double-neg72.4%
distribute-neg-frac272.4%
sub0-neg72.4%
associate-+l-72.4%
neg-sub072.4%
Simplified72.4%
Taylor expanded in x around inf 98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
add-cube-cbrt97.9%
pow297.9%
cbrt-div97.9%
+-commutative97.9%
div-inv97.9%
fma-define97.9%
pow-flip97.9%
metadata-eval97.9%
rem-cbrt-cube97.8%
cbrt-div97.6%
Applied egg-rr99.1%
unpow299.1%
unpow399.1%
Simplified99.1%
Taylor expanded in x around inf 98.8%
Final simplification98.8%
(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}
\\
\frac{2}{{x}^{3}}
\end{array}
Initial program 72.4%
+-commutative72.4%
associate-+r-72.4%
sub-neg72.4%
remove-double-neg72.4%
neg-sub072.4%
associate-+l-72.4%
neg-sub072.4%
distribute-neg-frac272.4%
distribute-frac-neg272.4%
associate-+r+72.4%
+-commutative72.4%
remove-double-neg72.4%
distribute-neg-frac272.4%
sub0-neg72.4%
associate-+l-72.4%
neg-sub072.4%
Simplified72.4%
Taylor expanded in x around inf 98.2%
Final simplification98.2%
(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 72.4%
Final simplification72.4%
(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 72.4%
+-commutative72.4%
associate-+r-72.4%
sub-neg72.4%
remove-double-neg72.4%
neg-sub072.4%
associate-+l-72.4%
neg-sub072.4%
distribute-neg-frac272.4%
distribute-frac-neg272.4%
associate-+r+72.4%
+-commutative72.4%
remove-double-neg72.4%
distribute-neg-frac272.4%
sub0-neg72.4%
associate-+l-72.4%
neg-sub072.4%
Simplified72.4%
Taylor expanded in x around inf 72.0%
Final simplification72.0%
(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 72.4%
+-commutative72.4%
associate-+r-72.4%
sub-neg72.4%
remove-double-neg72.4%
neg-sub072.4%
associate-+l-72.4%
neg-sub072.4%
distribute-neg-frac272.4%
distribute-frac-neg272.4%
associate-+r+72.4%
+-commutative72.4%
remove-double-neg72.4%
distribute-neg-frac272.4%
sub0-neg72.4%
associate-+l-72.4%
neg-sub072.4%
Simplified72.4%
Taylor expanded in x around 0 5.2%
Final simplification5.2%
(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 72.4%
+-commutative72.4%
associate-+r-72.4%
sub-neg72.4%
remove-double-neg72.4%
neg-sub072.4%
associate-+l-72.4%
neg-sub072.4%
distribute-neg-frac272.4%
distribute-frac-neg272.4%
associate-+r+72.4%
+-commutative72.4%
remove-double-neg72.4%
distribute-neg-frac272.4%
sub0-neg72.4%
associate-+l-72.4%
neg-sub072.4%
Simplified72.4%
Taylor expanded in x around inf 72.0%
Taylor expanded in x around 0 5.2%
Final simplification5.2%
(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 72.4%
+-commutative72.4%
associate-+r-72.4%
sub-neg72.4%
remove-double-neg72.4%
neg-sub072.4%
associate-+l-72.4%
neg-sub072.4%
distribute-neg-frac272.4%
distribute-frac-neg272.4%
associate-+r+72.4%
+-commutative72.4%
remove-double-neg72.4%
distribute-neg-frac272.4%
sub0-neg72.4%
associate-+l-72.4%
neg-sub072.4%
Simplified72.4%
Taylor expanded in x around inf 72.0%
add-sqr-sqrt24.3%
sqrt-unprod12.8%
div-inv12.8%
div-inv12.8%
swap-sqr12.8%
metadata-eval12.8%
inv-pow12.8%
inv-pow12.8%
pow-prod-up11.2%
metadata-eval11.2%
*-un-lft-identity11.2%
sqrt-pow16.1%
metadata-eval6.1%
*-un-lft-identity6.1%
metadata-eval6.1%
inv-pow6.1%
cancel-sign-sub-inv6.1%
div-inv6.1%
frac-2neg6.1%
metadata-eval6.1%
frac-sub57.8%
Applied egg-rr57.8%
Taylor expanded in x around 0 6.1%
Final simplification6.1%
(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 72.4%
+-commutative72.4%
associate-+r-72.4%
sub-neg72.4%
remove-double-neg72.4%
neg-sub072.4%
associate-+l-72.4%
neg-sub072.4%
distribute-neg-frac272.4%
distribute-frac-neg272.4%
associate-+r+72.4%
+-commutative72.4%
remove-double-neg72.4%
distribute-neg-frac272.4%
sub0-neg72.4%
associate-+l-72.4%
neg-sub072.4%
Simplified72.4%
Taylor expanded in x around 0 3.3%
Taylor expanded in x around inf 3.3%
Final simplification3.3%
(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 2024081
(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))))