
(FPCore (x) :precision binary64 (log (+ (/ 1.0 x) (/ (sqrt (- 1.0 (* x x))) x))))
double code(double x) {
return log(((1.0 / x) + (sqrt((1.0 - (x * x))) / x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((1.0d0 / x) + (sqrt((1.0d0 - (x * x))) / x)))
end function
public static double code(double x) {
return Math.log(((1.0 / x) + (Math.sqrt((1.0 - (x * x))) / x)));
}
def code(x): return math.log(((1.0 / x) + (math.sqrt((1.0 - (x * x))) / x)))
function code(x) return log(Float64(Float64(1.0 / x) + Float64(sqrt(Float64(1.0 - Float64(x * x))) / x))) end
function tmp = code(x) tmp = log(((1.0 / x) + (sqrt((1.0 - (x * x))) / x))); end
code[x_] := N[Log[N[(N[(1.0 / x), $MachinePrecision] + N[(N[Sqrt[N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{1}{x} + \frac{\sqrt{1 - x \cdot x}}{x}\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (log (+ (/ 1.0 x) (/ (sqrt (- 1.0 (* x x))) x))))
double code(double x) {
return log(((1.0 / x) + (sqrt((1.0 - (x * x))) / x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((1.0d0 / x) + (sqrt((1.0d0 - (x * x))) / x)))
end function
public static double code(double x) {
return Math.log(((1.0 / x) + (Math.sqrt((1.0 - (x * x))) / x)));
}
def code(x): return math.log(((1.0 / x) + (math.sqrt((1.0 - (x * x))) / x)))
function code(x) return log(Float64(Float64(1.0 / x) + Float64(sqrt(Float64(1.0 - Float64(x * x))) / x))) end
function tmp = code(x) tmp = log(((1.0 / x) + (sqrt((1.0 - (x * x))) / x))); end
code[x_] := N[Log[N[(N[(1.0 / x), $MachinePrecision] + N[(N[Sqrt[N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{1}{x} + \frac{\sqrt{1 - x \cdot x}}{x}\right)
\end{array}
(FPCore (x) :precision binary64 (log (* (- -1.0 (sqrt (fma (- x) x 1.0))) (/ -1.0 x))))
double code(double x) {
return log(((-1.0 - sqrt(fma(-x, x, 1.0))) * (-1.0 / x)));
}
function code(x) return log(Float64(Float64(-1.0 - sqrt(fma(Float64(-x), x, 1.0))) * Float64(-1.0 / x))) end
code[x_] := N[Log[N[(N[(-1.0 - N[Sqrt[N[((-x) * x + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\left(-1 - \sqrt{\mathsf{fma}\left(-x, x, 1\right)}\right) \cdot \frac{-1}{x}\right)
\end{array}
Initial program 100.0%
lift-+.f64N/A
lift-/.f64N/A
metadata-evalN/A
distribute-neg-fracN/A
div-invN/A
lift-/.f64N/A
neg-mul-1N/A
lift-/.f64N/A
frac-2negN/A
div-invN/A
distribute-frac-neg2N/A
lift-/.f64N/A
neg-mul-1N/A
distribute-rgt-outN/A
lower-*.f64N/A
lift-/.f64N/A
div-invN/A
lower-/.f64N/A
lower-+.f64N/A
lower-neg.f64100.0
lift--.f64N/A
lift-*.f64N/A
cancel-sign-sub-invN/A
+-commutativeN/A
Applied rewrites100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (log (/ (+ (sqrt (fma (- x) x 1.0)) 1.0) x)))
double code(double x) {
return log(((sqrt(fma(-x, x, 1.0)) + 1.0) / x));
}
function code(x) return log(Float64(Float64(sqrt(fma(Float64(-x), x, 1.0)) + 1.0) / x)) end
code[x_] := N[Log[N[(N[(N[Sqrt[N[((-x) * x + 1.0), $MachinePrecision]], $MachinePrecision] + 1.0), $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{\sqrt{\mathsf{fma}\left(-x, x, 1\right)} + 1}{x}\right)
\end{array}
Initial program 100.0%
lift-+.f64N/A
lift-/.f64N/A
div-invN/A
lift-/.f64N/A
distribute-rgt1-inN/A
lift-/.f64N/A
un-div-invN/A
lower-/.f64N/A
lower-+.f64100.0
lift--.f64N/A
lift-*.f64N/A
cancel-sign-sub-invN/A
+-commutativeN/A
lower-fma.f64N/A
lower-neg.f64100.0
Applied rewrites100.0%
(FPCore (x) :precision binary64 (log (/ (fma (* x x) -0.5 2.0) x)))
double code(double x) {
return log((fma((x * x), -0.5, 2.0) / x));
}
function code(x) return log(Float64(fma(Float64(x * x), -0.5, 2.0) / x)) end
code[x_] := N[Log[N[(N[(N[(x * x), $MachinePrecision] * -0.5 + 2.0), $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{\mathsf{fma}\left(x \cdot x, -0.5, 2\right)}{x}\right)
\end{array}
Initial program 100.0%
Taylor expanded in x around 0
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6499.1
Applied rewrites99.1%
(FPCore (x) :precision binary64 (log (/ 2.0 x)))
double code(double x) {
return log((2.0 / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log((2.0d0 / x))
end function
public static double code(double x) {
return Math.log((2.0 / x));
}
def code(x): return math.log((2.0 / x))
function code(x) return log(Float64(2.0 / x)) end
function tmp = code(x) tmp = log((2.0 / x)); end
code[x_] := N[Log[N[(2.0 / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{2}{x}\right)
\end{array}
Initial program 100.0%
Taylor expanded in x around 0
lower-/.f6498.9
Applied rewrites98.9%
(FPCore (x) :precision binary64 (log (* -0.5 x)))
double code(double x) {
return log((-0.5 * x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((-0.5d0) * x))
end function
public static double code(double x) {
return Math.log((-0.5 * x));
}
def code(x): return math.log((-0.5 * x))
function code(x) return log(Float64(-0.5 * x)) end
function tmp = code(x) tmp = log((-0.5 * x)); end
code[x_] := N[Log[N[(-0.5 * x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(-0.5 \cdot x\right)
\end{array}
Initial program 100.0%
Taylor expanded in x around 0
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6499.1
Applied rewrites99.1%
Taylor expanded in x around inf
Applied rewrites0.0%
herbie shell --seed 2024272
(FPCore (x)
:name "Hyperbolic arc-(co)secant"
:precision binary64
(log (+ (/ 1.0 x) (/ (sqrt (- 1.0 (* x x))) x))))