Re: [PATCH 1/3] Compiler attributes: Introduce the __preserve_most function attribute

[Miguel Ojeda]

On Wed, Aug 2, 2023 at 6:51 PM Marco Elver <elver@xxxxxxxxxx> wrote:
>
> Mark says that there may be an issue with using this in combination
> with ftrace because arm64 tracing relies on AAPCS. Probably not just
> arm64, but also other architectures (x86?).
>
> To make this safe, I'm going to move __preserve_most to
> compiler_types.h and always pair it with notrace and some comments in
> v2.

Sounds good, thanks! The patch here was otherwise good in terms of
`compiler_attributes.h`.

I was also thinking about the implications for Rust. I guess if we
need to call them, we will go through a C helper for the moment, and
later on if we get cross-language LTO (or the LLVM IR hacks), it will
hopefully not be a performance penalty.

Cheers,
Miguel