[clang] [llvm] [LLVMABI] Add support for SVE types in the LLVM ABI library (PR #221375)

[Madhur Amilkanthwar via cfe-commits]

madhur13490 wrote:

Thanks — the TupleType refactor, the IRTypeMapper tests, and the predicate i1/i8 comments+test all look good.

Couple of things I'd like to nail down though. Switching the unimplemented default from `Direct` to `Ignore` is a nice touch, but it doesn't actually get us past the debug cross-check — `Ignore` still doesn't match the classic path's Indirect for a register-exhausted SVE tuple, so a debug clang still aborts under `-fexperimental-abi-lowering` (I rebuilt with your latest and it still reproduces). That's fine as a known gap, I just think it should be called out in the PR description, and it'd be good to know #218799 is landing right behind this so that window stays small.

Same deal with `__mfp8` and the fixed-length `svmfloat8` — those still hit `reportFatalInternalError` even though the classic path handles them. Happy to treat it as not-implemented-yet, just want it acknowledged.

LGTM, otherwise. Thanks!


https://github.com/llvm/llvm-project/pull/221375