[clang] [llvm] [AMDGPU] Add async variants of tensor load/store LDS intrinsics. (PR #200775)

[Sameer Sahasrabuddhe via cfe-commits]

ssahasra wrote:

>     1. Existing users already have to manually call waits on tensorcnt, so making this intrinsic participate in the asyncmark scheme won't break their code and

Ok, now some things clicked in place about this confusing exchange of emails. I have been assuming that tensor operations are also covered automatically. If they are not, then there is no compatibility issue with "intrinsics already out there".

> 2. The hardware isn't out yet - now is the time where a somewhat breaking change like this is least unreasonable

Well, that depends on what "out" means. We do have the chance to rename the existing intrinsic with `.async`, and possibly auto-upgrade old occurrences. Renaming the equivalent Clang builtin will break source code that exists "out there somewhere". Eventually, this builtin will get listed [here](
https://llvm.org/docs/AMDGPUAsyncOperations.html#memory-accesses), but we want to reach a point where we can simply say "all `.async` intrinsics".




https://github.com/llvm/llvm-project/pull/200775