[llvm] [SystemZ] Eliminate call sequence instructions early. (PR #77812)

[Ulrich Weigand via llvm-commits]

uweigand wrote:

> It may be that even though there seem to be some slight advantage for the phys-reg arguments (spilling/copys), perhaps that doesn't matter. If benchmarks show no actual difference, maybe they could just be removed during isel regardless.

Do you have any numbers how benchmarks would be affected by just removing the instructions early?

> Alternatively, as stated in the comment, maybe the MIScheduler could be improved here.

Do we know what specifically could be improved?  (I guess we'd have to identify some actual regression first ...)


https://github.com/llvm/llvm-project/pull/77812