[PATCH] D76286: [X86][MC] Support enhanced relaxation for branch align

[Philip Reames via Phabricator via llvm-commits]

reames accepted this revision.
reames added a comment.
This revision is now accepted and ready to land.

LGTM w/one required change before submit.  This desperately needs test cases demonstrating the padding of instructions which aren't relaxable.  Please add at least a couple.  I'm fine adding some additional ones in a separate commit, but landing this without any would be inappropriate.

On the memory usage, I think the demonstrated results are not great - 45% increase worse case in LTO on *spec* is actually pretty bad -, but it's a reasonable starting point to optimize from.  The non-LTO maximum looks a lot more reasonable, and I suspect this is good enough for many real users.  We can continue iterating on the representation to reduce memory usage in tree.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D76286/new/

https://reviews.llvm.org/D76286