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Re: How could I get alias set information from data_reference_p


On Tue, Jul 14, 2009 at 11:03, Sebastian Pop<sebpop@gmail.com> wrote:
>> Why do you need alias-set numbers?
>
> We want to represent the alias set information as an extra subscript
> on memory accesses: for example,
>
> if we have A[10] and supposing that A is in alias set 6, this would be
> represented as "memory_access[6][10]".
>
> For B[3][4] with base array B in alias set 7 and 8, we would represent
> this as "memory_access[7][3][4] or memory_access[8][3][4]".
>
> The data dependence test that we currently have in the graphite branch
> would work with alias sets represented by an extra dimension to the
> array dimensions.

And by the way, right now we consider that all the data refs alias each
other, that means that we set the alias dimension of the memory
accesses to 1 for every data reference.  This makes the test very
conservative: in the example above, with the current implementation,
we would have:

A: memory_access[1][10]
B: memory_access[1][3][4]

Sebastian


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