[PATCH] D98230: [LSR] Add reconciliation of unfoldable offsets

[Jonas Paulsson via Phabricator via llvm-commits]

jonpa added a comment.

I currently don't see any performance wins on SystemZ with this patch, although there are still nice improvements in the output. My original motivation for this patch was improvement of lbm with 5-10%, but although I see that same hot loop still being helped there is no longer any impact on performance.

On SystemZ I see over SPEC:

  lay            :                55777                55520     -257
  agfi           :                  426                  297     -129
  lgr            :               842567               842448     -119
  lg             :              1049005              1048942      -63
  ...
  OPCDIFFS: -705

This is a nice improvement (especially as this is all about loops), but I am not sure it would be right to extend LSR with more than just a few lines without a clear motivation. So unless there is interest in this from other targets, I will pause my work on this until I see a clear win from it. As mentioned earlier there might be simpler ways of achieving the same result of the patch but in principal it does what it needs to now.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D98230/new/

https://reviews.llvm.org/D98230