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Re: [Patch Ping] [RFC] Alias export patch


Andrey Belevantsev wrote:
> Richard Guenther wrote:
>> I wonder how/if you deal with the problem that the tree loop optimizers
>> (ivopts mostly) generate new pointers as induction variables but we don't
>> run may_alias after them, so possibly all interesting (performance wise)
>> pointers do not have updated points-to information?  Do your numbers
>> (not performance) improve if you specify -fno-tree-loop-optimize?
> 
> Since the patch was created, we wanted to insert an additional 
> pass_may_alias before going out of ssa to cope with this problem. 
> However, as ivopts does not keep the points-to information updated, this 
> does not work -- gcc ICEs in verify_ssa. 

Last time i looked at this issue, it was because none of the aliasing
infrastructure (tree-ssa-alias, tree-ssa-structalias) was updated when
MEM_REF was introduced, and thus, doesn't treat MEM_REF like a pointer
dereference.

This causes some incorrect things to happen, and verify_ssa notices.


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