[all-commits] [llvm/llvm-project] bc569f: [RISCV] Add test case for shufflevector that gets ...

[Luke Lau via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: bc569f6eb3848361ae637de0a873e1c442958a71
      https://github.com/llvm/llvm-project/commit/bc569f6eb3848361ae637de0a873e1c442958a71
  Author: Luke Lau <luke at igalia.com>
  Date:   2024-02-06 (Tue, 06 Feb 2024)

  Changed paths:
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-shuffles.ll

  Log Message:
  -----------
  [RISCV] Add test case for shufflevector that gets scalarized. NFC

This shufflevector gets scalarized into a build_vector of extract_vector_elts
because the output type doesn't match the input vector type.

Normally this is combined back into a vector_shuffle in DAGCombine, but this
one fails because we don't consider a extract_subvector to be cheap,
specifically because it's at an index > 31.

This should be canonicalized back into a vector_shuffle at some point so we can
lower it as a vrgather.vv.