Re: [rfc] Moving bbs back to pools

[Jan Hubicka <hubicka at ucw dot cz>]

> Zdenek Dvorak <rakdver@kam.mff.cuni.cz> writes:
> 
> > The problem is, that it does not give any speedups (it is almost
> > completely compile-time neutral for compilation of preprocessed
> > gcc sources).  I will check whether moving also edges to pools
> > changes anything, but so far it does not seem very promising :-(
> 
> Does it make any difference for gcc.c-torture/compile/20001226-1.c?
> And of course it won't make any difference if you have enough memory
> that you never need to garbage collect without your patch.
> 
> I would like to see us implement this general GC approach even if we
> don't wind up moving the basic blocks into it today.  But we'll have
> to figure out what to do for PCH.  I guess the general approach would
> be to provide an optional swizzling routine as well as the marking

Well, rather than swizzling routines I think it is better to simply
avoid dumping the middle end datastructures to PCH when there are no
good reasons for that (that is definitly not the case of BBs)

Honza
> routine.  Then abort if gt_pch_save finds an object with a marking
> routine but no swizzling routine.  The swizzling routine would do
> something involving gt_pch_note_object and/or relocate_ptrs.  Or maybe
> we would need two routines, one to note and one to relocate.
> 
> Ian