Explore if the upcoming XCode 16.3 supports tail calling interpreters

[Fidget-Spinner]

Feature or enhancement

Proposal:

Xcode 16.3 seems to be getting a mixture of LLVM 17-19 features. It may be possible preserve_none ends up in there. If so, it would significantly boost interpreter performance if we can enable it.

https://developer.apple.com/documentation/xcode-release-notes/xcode-16_3-release-notes

We should play around with Xcode 16.3 and at least verify that it can/cannot support [[clang::musttail]] and __attribute__((preserve_none)).

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

[Fidget-Spinner]

Internal reports suggests this might be possible. Will let Ned know once Xcode 16.3 is released proper.

[ronaldoussoren]

The current Xcode beta (16.3 build 16E5104o) builds with --with-tail-call-interp and passes the test suite (e53d105).

The compiler claims to be Apple clang version 17.0.0 (clang-1700.0.9.2).

All of this on an M1 system, I'm assuming that this will also work for x86_64.