[Mlir-commits] [mlir] [mlir][ArmSME] Skip tile allocation for functions with no SME tile values (PR #227153)

[Benjamin Maxwell]

MacDue wrote:

> IIUC, this change is also making sure that we don't attempt "allocate" function arguments, which effectively means removing support for SME tiles as function arguments? That would make sense to me.

It's simply removing tile allocation from functions that don't contain ArmSME tile ops. If we had function arguments and ArmSME tile ops, tile allocation would also run. Note: Function arguments were never actually supported (they were only used for tests to generate dummy tile values -- LLVM IR generation would fail). 

Actually supporting function arguments would require implementing shared-ZA functions and defining an ABI for how tile values are passed, i.e. which arguments are assigned which tile ID. We never implemented this. 

https://github.com/llvm/llvm-project/pull/227153