That unfortunately also doesn't seem to speed things up either.
On Mon, May 12, 2014 at 12:07 PM, Steven G. Johnson <stevenj....@gmail.com>wrote: > On Sunday, May 11, 2014 1:55:47 PM UTC-4, Stefan Karpinski wrote: >> >> while nʹ > length(c) || c[nʹ] < 0 >> nʹ = iseven(nʹ) ? nʹ>>1 : 3nʹ+1 >> d += 1 >> end >> >> > As long as you are optimizing this, note that since 3n+1 is never odd you > can speed things up by doing > > if iseven(n) > n = n >> 1 > d += 1 > else > n = (3n + 1) >> 1 > d += 2 > end > > > You could save even more branches by doing a switch statement on the last > few bits of n, once some future version of LLVM(?) allows us to emulate > computed-goto functionality ( > https://github.com/JuliaLang/julia/issues/5410). >
