A question about Lua's register allocation

[Dibyendu Majumdar <mobile@...>]

An aspect of the Lua's code generator I don't fully understand are the
rules around register allocation. It appears that code generator does
not keep a list of free registers, instead the registers are treated
as a stack, so you have (in what cases?) free registers in stack
order.

My question is - suppose instead I maintain free list of registers and
not worry about stack order - are there any gotchas with that?

Thanks and Regards
Dibyendu