Re: [tree-ssa] Avoid nondeterminism in tree-ssanames

[Steven Bosscher <s dot bosscher at student dot tudelft dot nl>]

Hi,

> So what are we doing to the GC?  Are we fixing the zone collector so we
> can allocate pages to specific purposes?

Yes, I'm working on that.

The zone collector isn't broken, it just needs a few power-ups.  I've just 
commited a patch to mainline that allows you to create zones on the fly. Next 
I am going to try and put SSA names and PHI nodes in a separate zone.  Once 
that works, anything is possible ;-)

>   And will there or will there
> not be a free list mainatined within the zone?

Not within the zone collector, only after collecting objects (doh!).  You need 
to maintain your own objects cache.

For SSA names, I suppose we need a free list until there is a ggc_free.  
Recycling SSA names saved a lot of memory...

> I've abstracted out the use and def operands, Im going to make it work
> for vuse and vdef operands as well. These seem like very likely
> candidates for a zone as well, if it includes a free list, and can
> handle small allocations easily.

Hmm I thought ggc-page already handles small allocations quite nicely.  Just 
not the deallocations :-)

Gr.
Steven