[PATCH] D107009: [WIP][X86] combineX86ShuffleChain(): canonicalize mask elts picking from splats

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri abandoned this revision.
lebedev.ri added a comment.

TLDR: as i suspected, this is conceptually wrong, and should not have been accepted in the first place.
The individual matchers should instead be splat-aware, much like they are already zero/undef-aware
Indeed, there is some rudimentary support for that in e.g. `isTargetShuffleEquivalent()`/`IsElementEquivalent()`.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D107009/new/

https://reviews.llvm.org/D107009