[llvm] [AMDGPU] Occupancy w.r.t. workgroup size range is also a range (PR #123748)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> One potential issue I see is, the computation with workgroup size completely ignores `amdgpu-waves-per-eu` attribute, while it is considered with SGPRs and VGPRs. I understand the current implementation doesn't factor it in as well, but I don't know if we should.

As it should. The group size is a hard ABI requirement, and explicit. The amdgpu-waves-per-eu is an optimization hint and should not constrain the group size.

https://github.com/llvm/llvm-project/pull/123748