[all-commits] [llvm/llvm-project] d743af: [InstCombine] add tests for shuffle-of-shuffle; NFC

[Sanjay Patel via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d743aff7906784c054a0a7e9bc5db0011b8fe947
      https://github.com/llvm/llvm-project/commit/d743aff7906784c054a0a7e9bc5db0011b8fe947
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2022-09-28 (Wed, 28 Sep 2022)

  Changed paths:
    M llvm/test/Transforms/InstCombine/shuffle_select.ll

  Log Message:
  -----------
  [InstCombine] add tests for shuffle-of-shuffle; NFC


  Commit: e239198cdbbf2689ffe2c21ea8feab5b7a4a8a02
      https://github.com/llvm/llvm-project/commit/e239198cdbbf2689ffe2c21ea8feab5b7a4a8a02
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2022-09-28 (Wed, 28 Sep 2022)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
    M llvm/test/Transforms/InstCombine/shuffle_select.ll

  Log Message:
  -----------
  [InstCombine] fold select shuffles with shared operand together

We don't combine generic shuffles together in IR, but select
shuffles are a special-case because a select shuffle of a
select shuffle is just another select shuffle; codegen is
expected to efficiently lower those (select shuffles are also
the canonical form of a vector select with constant condition).


Compare: https://github.com/llvm/llvm-project/compare/1dd7e576d77f...e239198cdbbf