[all-commits] [llvm/llvm-project] 4c55cd: [GlobalISel] Fix known bits for G_BSWAP and B_BITR...

[Amara Emerson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4c55cdb00a8005826676848582b8450c21140e8a
      https://github.com/llvm/llvm-project/commit/4c55cdb00a8005826676848582b8450c21140e8a
  Author: Amara Emerson <amara at apple.com>
  Date:   2021-07-17 (Sat, 17 Jul 2021)

  Changed paths:
    M llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
    M llvm/unittests/CodeGen/GlobalISel/KnownBitsTest.cpp
    M llvm/unittests/CodeGen/GlobalISel/KnownBitsVectorTest.cpp

  Log Message:
  -----------
  [GlobalISel] Fix known bits for G_BSWAP and B_BITREVERSE not doing anything.

llvm::KnownBits::byteSwap() and reverse() don't modify in-place, so
we weren't actually computing anything. This was causing a miscompile on an
arm64 stage2 bootstrap clang build.