The VList paper - which I archived at http://trout.me.uk/lisp/vlist.pdf to avoid having to google the bloody thing every time - is an interesting hybrid.
Regarding section 4.1 and 8 in this paper, it uses several software implementations of MSB and gives a performance comparison between the VList and RAOTS from which it was derived. It doesn't utilize hardware instructions which can improve the MSB calculation and eliminate branches (eg, clz/lzcnt or bsr). It's worth having another look at RAOTS using an optimized MSB which will leverage instructions available in modern hardware, and see how its performance compares to the VList.
trout.me.uk/lisp/ and trout.me.uk/gc/ are both basically archives of "stuff I knew I'd suffer that problem with" and it's a pleasure every time the contents come in handy for people who aren't me.
Also back when I was still pretending to be a mathematician I used both GWBASIC and UBASIC for assorted purposes so thank -you- for the nostalgia kick.
Still sad that John Shutt (creator of 'kernel lisp') passed away while I was still procrastinating dropping him an email - I think the only other 'thank you' I've most regretted not sending in time was to Terry Pratchett.
