[PATCH] D66983: [WebAssembly] Add wasm-specific vector shuffle builtin and intrinsic

[Craig Topper via Phabricator via cfe-commits]

craig.topper added a comment.

x86 is aggressive about optimizing shuffles no matter where they came from. FWIW, InstCombine has a general rule that its not supposed to create a shuffle mask that didn't already exist in the IR except for special things like identity masks that would allow the shuffle to be removed.  DAG combine is supposed to check with TargetLowering::isShuffleMaskLegal.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D66983/new/

https://reviews.llvm.org/D66983