[PATCH] D36258: Disable loop peeling during full unrolling pass.

[Philip Reames via Phabricator via llvm-commits]

reames added a comment.

FYI, this patch causes a somewhat serious regression on one of our internal benchmarks.  Given we have a custom pass pipeline, it's definitely our responsibility to adapt to upstream changes not the other way around, but it would have helped us recognize the problem if either of two things had happened along with this patch:

1. The patch had been separated into two pieces: adding the new control know without changing the default and then a small patch changing the default.
2. The change had been announced in some way.  An email to llvm-dev probably would have been sufficient.

Given we're hardly the only ones with custom pass pipelines, I'd encourage everyone involved (author, reviewers, etc..) to think about the upgrade path in similar cases which arise in the future.


Repository:
  rL LLVM

https://reviews.llvm.org/D36258