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Re: Aliasing violation generated by fold_builtin_memcmp?
- From: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- To: dberlin at dberlin dot org
- Cc: gcc at gcc dot gnu dot org
- Date: Fri, 30 Sep 05 13:12:53 EDT
- Subject: Re: Aliasing violation generated by fold_builtin_memcmp?
Because the RTL level only supports type based aliasing, and very simple
TBAA at that.
But we're just talking about type-based aliasing.
You are saying that an access through this pointer can point to
anything, regardless of what we think it points to.
No. If you know what it points to by value-based information, that can
safely be used. The only thing is that you must use alias set 0 for
any type-based information.
This leaves 3 or 4 places at the tree level that need to be changed,
and possibly more later as more aliasing techniques are added.
I don't see why. Why is there more than one place that computes the alias
set of what a pointer might point to?