[all-commits] [llvm/llvm-project] 18e6a0: [X86][AVX] Extract SUBV_BROADCAST constant bits fr...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 18e6a03b1a15b2661259af15ae604b4c4850cd61
      https://github.com/llvm/llvm-project/commit/18e6a03b1a15b2661259af15ae604b4c4850cd61
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-08-06 (Fri, 06 Aug 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/pr51281.ll

  Log Message:
  -----------
  [X86][AVX] Extract SUBV_BROADCAST constant bits from just the lower subvector range (PR51281)

As reported on PR51281, an internal fuzz test encountered an issue when extracting constant bits from a SUBV_BROADCAST node from a constant pool source larger than the broadcasted subvector width.

The getTargetConstantBitsFromNode was assuming that the Constant would the same size as the subvector, resulting in the incorrect packing of the per-element bits data.

This patch attempts to solve this by using the SUBV_BROADCAST node to determine the subvector width, and then ensuring we extract only the lowest bits from Constant of that subvector bitsize.

Differential Revision: https://reviews.llvm.org/D107158


  Commit: dbce6a8d9d7c78e6aee989db8a9f29ad8b7cf0a7
      https://github.com/llvm/llvm-project/commit/dbce6a8d9d7c78e6aee989db8a9f29ad8b7cf0a7
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-08-06 (Fri, 06 Aug 2021)

  Changed paths:
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    A llvm/test/CodeGen/ARM/neon-copy.ll

  Log Message:
  -----------
  [ARM] Fold insert_subvector to concat_vectors

D107068 fixed the same problem on aarch64 but the arm variant wasn't exposed in existing test coverage.

I've copied the arm64-neon-copy tests (and stripped the intrinsic test from it) for testing on arm neon builds as well.


Compare: https://github.com/llvm/llvm-project/compare/aa2210a83069...dbce6a8d9d7c