[Polly] Generating code for changed memory accesses

[Tobias Grosser]

On 31/07/2014 08:13, Johannes Doerfert wrote:
> Attached the newest version which looks good I think.
>
> Thoughts?

Looks good so far.

Two remarks:

1)

As suggested in my earlier mail, I would prefer to move the tests first
and then change the implementation. This makes it clear to the reader
that the implementation does not change the tests, or, if it does, it 
makes clear which adjustments are necessary.
On the other side, there is no need to split of the IslExprBuilder 
changes as they are not tested at all in the separate patch.


2)

I also wonder if we actually want to compute the isl_ast_expr's already 
in IslAst.cpp. I think about this for two reasons:

  a) this would allow us to printing accesses and write test cases that
     check for those pretty printed changed accesses

  b) I think Yabin will not modify the access relations, but instead
     directly provide isl_ast_exprs. (In fact he is not even using the
     IslAst.cpp pass, but computes an entirely new ast). So from his
     perspective the IslCodeGeneration class is really an utility class
     that translates a certain IslAst into the corresponding LLVM-IR.

I would like you to address 1). Regarding 2): I think it would be nice 
to already do this in this patch, but if you prefer to get it in as it 
is and have a later discussion in case someone starts to work on
dumping accesses in -polly-ast or in case Yabin starts to make use of
this, that is fine with me as well.

Cheers,
Tobias