Re: [RFC] Design issues with multiple IRs

[Diego Novillo <dnovillo at redhat dot com>]

On Thu, 06 Dec 2001, Neil Booth wrote:

> Diego Novillo wrote:-
> 
> > Another place where we are abusing void pointers is in
> > annotations attached to flowgraph nodes and trees.  The 'aux'
> > fields are being used to hold analysis information.  For
> > instance, trees use the 'aux' pointer to hold a pointer to the
> > basic block that contains the tree (only for statement trees), a
> > pointer to a list of references for VAR_DECLs, a pointer to the
> > most recent definition of a VAR_DECL (for building the SSA web).
> 
> Why not use a union?
> 
That could be.  However, a union would increase the size of
*every* tree and basic block nodes.  We only allocate annotations
to very specific objects.

> If you give it a single letter, access is not so tedious, or wrap it
> in a macro like we do now.  But if you can make even a bit of progress
> on getting away from "everything is a tree" to "everything is a
> pointer to a specific type" like we discussed the other day, that
> would be great.
> 
I completely missed that thread.  Would you mind giving me a
pointer to it?  A quick search didn't produce anything
interesting.

Thanks.  Diego.