[all-commits] [llvm/llvm-project] 426681: [AArch64] Convert negative constant aarch64_neon_s...

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4266815f4d82bd7571bf6ae85eb15fcc0b3ae37e
      https://github.com/llvm/llvm-project/commit/4266815f4d82bd7571bf6ae85eb15fcc0b3ae37e
  Author: David Green <david.green at arm.com>
  Date:   2023-10-17 (Tue, 17 Oct 2023)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/test/CodeGen/AArch64/arm64-vshift.ll

  Log Message:
  -----------
  [AArch64] Convert negative constant aarch64_neon_sshl to VASHR (#68918)

In replacing shifts by splat with constant shifts, we can handle
negative shifts by flipping the sign and using a VASHR or VLSHR.