
(FPCore (x) :precision binary64 (- (/ 1.0 x) (/ 1.0 (tan x))))
double code(double x) {
return (1.0 / x) - (1.0 / tan(x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / x) - (1.0d0 / tan(x))
end function
public static double code(double x) {
return (1.0 / x) - (1.0 / Math.tan(x));
}
def code(x): return (1.0 / x) - (1.0 / math.tan(x))
function code(x) return Float64(Float64(1.0 / x) - Float64(1.0 / tan(x))) end
function tmp = code(x) tmp = (1.0 / x) - (1.0 / tan(x)); end
code[x_] := N[(N[(1.0 / x), $MachinePrecision] - N[(1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x} - \frac{1}{\tan x}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (/ 1.0 x) (/ 1.0 (tan x))))
double code(double x) {
return (1.0 / x) - (1.0 / tan(x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / x) - (1.0d0 / tan(x))
end function
public static double code(double x) {
return (1.0 / x) - (1.0 / Math.tan(x));
}
def code(x): return (1.0 / x) - (1.0 / math.tan(x))
function code(x) return Float64(Float64(1.0 / x) - Float64(1.0 / tan(x))) end
function tmp = code(x) tmp = (1.0 / x) - (1.0 / tan(x)); end
code[x_] := N[(N[(1.0 / x), $MachinePrecision] - N[(1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x} - \frac{1}{\tan x}
\end{array}
(FPCore (x) :precision binary64 (/ x (+ 3.0 (* x (* x (+ -0.2 (* (* x x) -0.005714285714285714)))))))
double code(double x) {
return x / (3.0 + (x * (x * (-0.2 + ((x * x) * -0.005714285714285714)))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = x / (3.0d0 + (x * (x * ((-0.2d0) + ((x * x) * (-0.005714285714285714d0))))))
end function
public static double code(double x) {
return x / (3.0 + (x * (x * (-0.2 + ((x * x) * -0.005714285714285714)))));
}
def code(x): return x / (3.0 + (x * (x * (-0.2 + ((x * x) * -0.005714285714285714)))))
function code(x) return Float64(x / Float64(3.0 + Float64(x * Float64(x * Float64(-0.2 + Float64(Float64(x * x) * -0.005714285714285714)))))) end
function tmp = code(x) tmp = x / (3.0 + (x * (x * (-0.2 + ((x * x) * -0.005714285714285714))))); end
code[x_] := N[(x / N[(3.0 + N[(x * N[(x * N[(-0.2 + N[(N[(x * x), $MachinePrecision] * -0.005714285714285714), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{3 + x \cdot \left(x \cdot \left(-0.2 + \left(x \cdot x\right) \cdot -0.005714285714285714\right)\right)}
\end{array}
Initial program 6.8%
Taylor expanded in x around 0
*-lowering-*.f64N/A
+-commutativeN/A
distribute-lft-inN/A
*-commutativeN/A
associate-+r+N/A
*-commutativeN/A
associate-*l*N/A
metadata-evalN/A
cancel-sign-sub-invN/A
associate-*l*N/A
*-commutativeN/A
associate-+l-N/A
*-commutativeN/A
distribute-lft-out--N/A
--lowering--.f64N/A
Simplified99.4%
flip--N/A
clear-numN/A
un-div-invN/A
/-lowering-/.f64N/A
clear-numN/A
flip--N/A
/-lowering-/.f64N/A
--lowering--.f64N/A
Applied egg-rr100.0%
Taylor expanded in x around 0
+-lowering-+.f64N/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
sub-negN/A
metadata-evalN/A
+-commutativeN/A
+-lowering-+.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f64100.0%
Simplified100.0%
(FPCore (x) :precision binary64 (/ x (+ 3.0 (* -0.2 (* x x)))))
double code(double x) {
return x / (3.0 + (-0.2 * (x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = x / (3.0d0 + ((-0.2d0) * (x * x)))
end function
public static double code(double x) {
return x / (3.0 + (-0.2 * (x * x)));
}
def code(x): return x / (3.0 + (-0.2 * (x * x)))
function code(x) return Float64(x / Float64(3.0 + Float64(-0.2 * Float64(x * x)))) end
function tmp = code(x) tmp = x / (3.0 + (-0.2 * (x * x))); end
code[x_] := N[(x / N[(3.0 + N[(-0.2 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{3 + -0.2 \cdot \left(x \cdot x\right)}
\end{array}
Initial program 6.8%
Taylor expanded in x around 0
*-lowering-*.f64N/A
metadata-evalN/A
cancel-sign-sub-invN/A
--lowering--.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f6499.2%
Simplified99.2%
flip3--N/A
clear-numN/A
un-div-invN/A
/-lowering-/.f64N/A
clear-numN/A
flip3--N/A
/-lowering-/.f64N/A
sub-negN/A
+-lowering-+.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
metadata-eval99.8%
Applied egg-rr99.8%
Taylor expanded in x around 0
+-lowering-+.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f6499.8%
Simplified99.8%
Final simplification99.8%
(FPCore (x) :precision binary64 (* x (- 0.3333333333333333 (* (* x x) -0.022222222222222223))))
double code(double x) {
return x * (0.3333333333333333 - ((x * x) * -0.022222222222222223));
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (0.3333333333333333d0 - ((x * x) * (-0.022222222222222223d0)))
end function
public static double code(double x) {
return x * (0.3333333333333333 - ((x * x) * -0.022222222222222223));
}
def code(x): return x * (0.3333333333333333 - ((x * x) * -0.022222222222222223))
function code(x) return Float64(x * Float64(0.3333333333333333 - Float64(Float64(x * x) * -0.022222222222222223))) end
function tmp = code(x) tmp = x * (0.3333333333333333 - ((x * x) * -0.022222222222222223)); end
code[x_] := N[(x * N[(0.3333333333333333 - N[(N[(x * x), $MachinePrecision] * -0.022222222222222223), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(0.3333333333333333 - \left(x \cdot x\right) \cdot -0.022222222222222223\right)
\end{array}
Initial program 6.8%
Taylor expanded in x around 0
*-lowering-*.f64N/A
metadata-evalN/A
cancel-sign-sub-invN/A
--lowering--.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f6499.2%
Simplified99.2%
(FPCore (x) :precision binary64 (/ x 3.0))
double code(double x) {
return 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 x / 3.0;
}
def code(x): return x / 3.0
function code(x) return Float64(x / 3.0) end
function tmp = code(x) tmp = x / 3.0; end
code[x_] := N[(x / 3.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{3}
\end{array}
Initial program 6.8%
Taylor expanded in x around 0
*-lowering-*.f64N/A
metadata-evalN/A
cancel-sign-sub-invN/A
--lowering--.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f6499.2%
Simplified99.2%
flip3--N/A
clear-numN/A
un-div-invN/A
/-lowering-/.f64N/A
clear-numN/A
flip3--N/A
/-lowering-/.f64N/A
sub-negN/A
+-lowering-+.f64N/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
metadata-eval99.8%
Applied egg-rr99.8%
Taylor expanded in x around 0
Simplified99.1%
(FPCore (x) :precision binary64 (* x 0.3333333333333333))
double code(double x) {
return x * 0.3333333333333333;
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * 0.3333333333333333d0
end function
public static double code(double x) {
return x * 0.3333333333333333;
}
def code(x): return x * 0.3333333333333333
function code(x) return Float64(x * 0.3333333333333333) end
function tmp = code(x) tmp = x * 0.3333333333333333; end
code[x_] := N[(x * 0.3333333333333333), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.3333333333333333
\end{array}
Initial program 6.8%
Taylor expanded in x around 0
*-lowering-*.f6498.5%
Simplified98.5%
Final simplification98.5%
(FPCore (x) :precision binary64 (if (< (fabs x) 0.026) (* (/ x 3.0) (+ 1.0 (/ (* x x) 15.0))) (- (/ 1.0 x) (/ 1.0 (tan x)))))
double code(double x) {
double tmp;
if (fabs(x) < 0.026) {
tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0));
} else {
tmp = (1.0 / x) - (1.0 / tan(x));
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (abs(x) < 0.026d0) then
tmp = (x / 3.0d0) * (1.0d0 + ((x * x) / 15.0d0))
else
tmp = (1.0d0 / x) - (1.0d0 / tan(x))
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (Math.abs(x) < 0.026) {
tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0));
} else {
tmp = (1.0 / x) - (1.0 / Math.tan(x));
}
return tmp;
}
def code(x): tmp = 0 if math.fabs(x) < 0.026: tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0)) else: tmp = (1.0 / x) - (1.0 / math.tan(x)) return tmp
function code(x) tmp = 0.0 if (abs(x) < 0.026) tmp = Float64(Float64(x / 3.0) * Float64(1.0 + Float64(Float64(x * x) / 15.0))); else tmp = Float64(Float64(1.0 / x) - Float64(1.0 / tan(x))); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (abs(x) < 0.026) tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0)); else tmp = (1.0 / x) - (1.0 / tan(x)); end tmp_2 = tmp; end
code[x_] := If[Less[N[Abs[x], $MachinePrecision], 0.026], N[(N[(x / 3.0), $MachinePrecision] * N[(1.0 + N[(N[(x * x), $MachinePrecision] / 15.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / x), $MachinePrecision] - N[(1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\left|x\right| < 0.026:\\
\;\;\;\;\frac{x}{3} \cdot \left(1 + \frac{x \cdot x}{15}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{x} - \frac{1}{\tan x}\\
\end{array}
\end{array}
herbie shell --seed 2024155
(FPCore (x)
:name "invcot (example 3.9)"
:precision binary64
:pre (and (< -0.026 x) (< x 0.026))
:alt
(! :herbie-platform default (if (< (fabs x) 13/500) (* (/ x 3) (+ 1 (/ (* x x) 15))) (- (/ 1 x) (/ 1 (tan x)))))
(- (/ 1.0 x) (/ 1.0 (tan x))))