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Re: [PATCH] Fix PR32921, prune virtual operands of memory accesses based on TBAA
On 10/21/07, Daniel Berlin <dberlin@dberlin.org> wrote:
> On 10/21/07, Richard Guenther <rguenther@suse.de> wrote:
> > p.1_2 = { m.b }
> > m = { ANYTHING }
> > m.b = { ANYTHING }
> > D.1187_3 = { }
> > D.1185_4 = same as D.1187_3
> >
> > Pointed-to sets for pointers in test2
> >
> > p.1_2, points-to anything
>
> This is wrong.
> I wonder why it says this.
>
> Something in find_what_p_points_to is going wrong.
Regardless of why in this case we end up with points-to analysis
thinking it points to anything, what I'm thinking is this: if PTA
thinks that the pointer points-to anything, wouldn't it make sense to
fallback to TBAA and conclude that the symbol cannot be in the
points-to set?
IIUC, Richard's patch does this analysis during VOP pruning. I think
that it makes more sense doing it inside PTA directly. Unless I'm
misunderstanding the whole problem.