[llvm] peephole-opt: Fold uses of REG_SEQUENCE subregisters (WIP) (PR #161225)

[Frederik Harwath via llvm-commits]

frederik-h wrote:

@arsenm Some time ago you have suggested to look into removing REG_SEQUENCE uses in peephole-opt. I have tried to adjust peephole-opt to this end and the approach seems viable to me. The cases that should be handled by this optimization still need to be narrowed down. I could use some input on this. The resulting dead REG_SEQUENCE instructions resulting are also not yet removed.

https://github.com/llvm/llvm-project/pull/161225