Re: alloca and GC

[Dirk Herrmann]

On 30 Jan 2001, Michael Livshin wrote:

> Keisuke: you already have two versions of your VM, one GCC-specific
> and the other generic ANSI C, right?  no problem then, let those
> non-gcc using folks suffer. ;)

Actually, I rather think that even if alloca was available, that it is
questionable whether it should be used, following the argumentation that
was posted to this list before by others:  The stack has to be
conservatively scanned, i. e. alloca-ting large regions on the stack for
bytecode increases the amount of memory that has always to be scanned,
independent of how clever a potential generational garbage collection
might be implemented.

Maybe I missed some point in the beginning of the discussion, but what
is the major benefit of using alloca in contrast to an ordinary
malloc in this particular case?  Doesn't bytecode have to be stored on the
heap anyway, belonging to some function object?

Best regards,
Dirk Herrmann