[PATCH] D132784: [AArch64][TTI] Set the cost of XTN to 1 for 2xi64 (to 2xi32) and 8xi16 (to8xi8).

[Dave Green via Phabricator via llvm-commits]

dmgreen added reviewers: jaykang10, CarolineConcatto, fhahn.
dmgreen added a comment.

This certainly sounds sensible.  There are some tests in llvm/test/Analysis/CostModel/AArch64/cast.ll that suggest these costs are already 1, but that seems to not apply in all situations. I don't really understand why at the moment, I would guess that something is incorrectly marking it as free, but only some of the time.

Can you add a test case to show where it does give a difference in the costs?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D132784/new/

https://reviews.llvm.org/D132784