[llvm-branch-commits] [llvm] [AMDGPU] Add `.amdgpu.info` section for per-function metadata (PR #192384)

[Shilei Tian via llvm-branch-commits]

shiltian wrote:

> So this metadata is per-function? How do you identify the kernel from this exclude section? Also, I know they serve different purposes, but we'll now have three different methods to communicate register counts, kernel descriptors, msgpack .notes, and this.

KD and msgpack (HSA metadata) are only for kernels. They are the contract between the compiler and downstream components, so we can't extend them.

The metadata introduced in this PR is per-function and used by the linker to finalize the values that will be patched into KD and HSA metadata. It is a contract between the compiler and the linker, so we can technically change it freely to better support linking before we promise a stable ABI. It will be discarded in the final code object.

https://github.com/llvm/llvm-project/pull/192384