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Subject: Re: [PATCH] Make alias_sets_conflict_p less conservative
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> Err, right.  But tree aliasing is computing a representation for TBAA,
> using alias set conflict queries but _not_ looking at individual accesses.

That seems quite wrong to me.

> So, is alias_set_subset_of () wrong as currently implemented?  Does
> it lack the ase->has_zero_child test in your opinion?  Otherwise I'll
> try using that for these queries.

I don't know enough to answer those questions.

What I *do* know is that if you have x.y, with y addressable, any code
that looks at the alias set of X *for any reason* is broken.