[Bug tree-optimization/32377] can't determine dependence (source/destination overlap without more than size)

["irar at il dot ibm dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #5 from irar at il dot ibm dot com  2007-07-02 12:20 -------
(In reply to comment #4)
> Looks like the data-dependence analysis is doing it's job

I am not sure about that. I tried the following cases and got distance 1 (and
direction positive) in all of them for load and store to ia pair.

  for (i = 0; i < N; i++){
    ia[i+1] = ia[i] * 4;
  }

  for (i = 0; i < N; i++){
    ia[i] = ia[i+1] * 4;
  }

  for (i = 0; i < N; i++){
    ia[i+1] = 0;
    ic[i] = ia[i] * 4;
  }

  for (i = 0; i < N; i++){
    ia[i] = 0;
    ic[i] = ia[i+1] * 4;
  }

What am I missing?

Thanks,
Ira


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32377