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Re: Incorrect bitfield aliasing with Tree SSA
On 6/18/07, Richard Kenner <kenner@vlsi1.ultra.nyu.edu> wrote:
> It gives you the alias set of the parent, which, for the reason that
> OTHER THINGS USE THE ALIAS SET SPLAY TREES, gives the wrong answer.
Can you give a few sentence explanation of what "alias set splay trees"
are and why they aren't using the alias set mechanism?
They are the alias set mechanism, which you don't seem to understand.
They always have been.
How do you believe we determine whether two alias sets conflict, or
are related at all?
> > I'm not sure what a "TBAA forest" is, but keep in mind that, at least in
> > Ada, we have many different types (meaning different tree nodes) that have
> > the same alias set and we really do mean that they are to conflict.
>
> That's nice.
But are they handled properly?
Yes
> There are other questions we ask about alias sets other than "do these
> two alias sets conflict" (which is asking whether they are subsets of
> each other, or equal). We have good reasons to ask these questions.
Can you give examples of those questions?
I'd rather not explain all of alias.c to you in an email message, to be honest