[PATCH] D121903: [MachineCopyPropagation] More robust isForwardableRegClassCopy

[Vang Thao via Phabricator via llvm-commits]

vangthao added a comment.

Would this disallow AGPR to AGPR copy propagation completely on sub-targets with no AGPR->AGPR copy capability? I think in some cases we can still propagate an AGPR. For example:

  liveins: $agpr0
    $agpr1 = COPY $agpr0
    $agpr2 = COPY $agpr1
    $agpr3 = COPY $agpr2

$agpr0 can be propagated and we would not require more than 1 set of v_accvgpr_read/write when expanding the copys.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D121903/new/

https://reviews.llvm.org/D121903