Hi Scott,

> > We discussed these changes but nobody (including me) was 
> > able to recreate the improvement you reported.
> 
> It should have been straightforward with the new methodcache. AFAIK,
> nobody else tested it. (Or at least, I saw no discussion other than
> plans to drop it because it was considered too invasive.)

No, actually I tested it but given my newly found knowledge about the
effects of branch-prediction it may well be that my tests were *way* off.
Considering that #benchFib always sends the same selector your scheme would
bring no improvement if the selector is in the first slot (aha!) and I think
this may have been what I based my evaluation upon.

> Did the root-table-overflow patch go in? (That one was where if the
> root table was about to overflow, immediately microGC, then tenure.)

Not sure - Tim?

> > Huh? I don't quite understand what you're saying here. 
> > Where was that insn? What did it do? How was it related
> > to the mcache?
> 
> It was in commonLookup, here's the code snippet out of interp.c

[snipped away]

Yes, if the miss-rate on the first branch is really around 66% that should
help. I'll give it another try.

> -- This comparison above is apples-oranges, but I can't easily go
> -- through my earlier posts to identify if I have a better one.

Fortunately I can (and I will ;-) my personal Squeak archives range _way_
back.

Cheers,
  - Andreas