[PATCH] D120953: [AArch64][SelectionDAG] Supports unpklo/hi instructions to reduce the number of loads

[Paul Walker via Phabricator via llvm-commits]

paulwalker-arm added a comment.

By directly supported I mean those which are legal and thus have isel patterns. Which I think boils down to:

  for (auto Op : {ISD::ZEXTLOAD, ISD::SEXTLOAD}) {
    setLoadExtAction(Op, MVT::nxv2i64, MVT::nxv2i8, Legal);
    setLoadExtAction(Op, MVT::nxv2i64, MVT::nxv2i16, Legal);
    setLoadExtAction(Op, MVT::nxv2i64, MVT::nxv2i32, Legal);
    setLoadExtAction(Op, MVT::nxv4i32, MVT::nxv4i8, Legal);
    setLoadExtAction(Op, MVT::nxv4i32, MVT::nxv4i16, Legal);
    setLoadExtAction(Op, MVT::nxv8i16, MVT::nxv8i8, Legal);
  }

I should also mention that downstream we had started work to use separate legalisation tables for each of LOAD, MLOAD and MGATHER but parked it until there was a real need.  Perhaps this is that need and we should pick that work back up, but let's see how this work plays out first.


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  https://reviews.llvm.org/D120953/new/

https://reviews.llvm.org/D120953