Tree-ssa status with POOMA

[Daniel Berlin]

>
> Well - the number usually _is_ interesting for me, as if ggc can't help
> and gcc goes into swap, I'm very unhappy ;)  And for comparisons on the
> same machine it is ok, too.  But I never found -fmem-report useful, as
> it doesn't tell me it needed 1.2Gigs of ram and gone into swap, but 
> always
> had numbers way lower. Like
>
> Total        348M        214M       3409k
>
> for a compilation requiring ~900MB of ram.

This is either due to memory fragmentation, or we've got some serious 
non-ggc'd leakage.
A copying collector would take care of it.
When I had implemented one, I saw significant reductions in used 
memory, but not ~300% (which is what would be necessary for these 
numbers above to add up).

For whatever that is worth.
--Dan