[PATCH] D12345: [Reassociate]: Add intermediate subtract instructions created while negating to be redone later for more reassociate opportunities

[Chad Rosier via llvm-commits]

mcrosier added a comment.

In http://reviews.llvm.org/D12345#233382, @aditya_nandakumar wrote:

> I expect when the pass finishes, running reassociate again should not make any changes (the output should already be in canonicalized form - please correct me if this is not a valid expectation).


I think this should be the goal, but, as you're finding out, this isn't reality.  IIRC, a similar question was asked and I believe David provided a similar comment.  The approach you're taking seems to be moving us closer and that's a good thing.  We just need to make sure we're not going overboard; we should only revisit things that have changed and only when that change is likely to expose other opportunities.


Repository:
  rL LLVM

http://reviews.llvm.org/D12345