[PATCH] D60783: [LoopPred] Implement a version of the profitability heuristic w/o BPI

[Philip Reames via Phabricator via llvm-commits]

reames added a comment.

In D60783#1469458 <https://reviews.llvm.org/D60783#1469458>, @hfinkel wrote:

> > In the new pass manager, getting access to BPI reliability is a challenge. In practice, we've been running downstream with a variation of this non-BPI based heuristic.
>
> Can you please explain why? The new pass manager was supposed to make our problems getting a hold of analysis results in different places easier, not harder.


I haven't dug through this entirely, but I'm seeing invalidation of BPI being done outside of a loop pass manager.  Which is a bit of a problem if I have a loop pass manager which contains two passes, the *first* of which invalidates, and the *second* uses.  We appear to be using stale info for the second pass without notice or error.


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D60783/new/

https://reviews.llvm.org/D60783