[clang] [libcxx] [llvm] [openmp] [libcxxabi] [compiler-rt] [flang] [mlir] [lldb] [clang-tools-extra] [MachineCopyPropagation] When the source of PreviousCopy is undef, we cannot replace sub register (PR #74682)

[via cfe-commits]

DianQK wrote:

> I'll try and take a look at the patch. Perhaps you are right that we need a new method for the debug info to use.

Based on https://github.com/llvm/llvm-project/blob/fd8fa31c55a3413f643443ecf3301441428ce513/llvm/docs/InstrRefDebugInfo.md?plain=1#L125-L127, perhaps we could add an `isCopyLikeInstr` method? This should be a good name while changing very little.I 'll give it a try later.

https://github.com/llvm/llvm-project/pull/74682