[llvm] [SystemZ] XPLINK64: emit narrow sign/zero-extend instructions for sub-i32 formal args (PR #206833)

[Zibi Sarbinowski via llvm-commits]

zibi2 wrote:

> Specifically, the `CC_XPLINK_Promote_i32` routine goes to a lot of effort distinguishing various cases in order to make a decision whether to consider the input `AExt` to `i32` or `AExt` to `i64` - but those two _have exactly the same semantics_:

You are right and I agree with above.  Preliminary tests shows the implementation indeed can be simplified. I'm currently going to test them on z/OS and if everything goes well I will post either  later tonight or tomorrow.

https://github.com/llvm/llvm-project/pull/206833