[llvm] [AMDGPU] Detect kills in register sets when trying to form V_CMPX instructions. (PR #68293)

[Thomas Symalla via llvm-commits]

tsymalla wrote:

Do some additional bookkeeping to store the MachineOperands that are potentially left "killed" and remove the kill flag on them at the end.

https://github.com/llvm/llvm-project/pull/68293