Re: git: 9d87c1aac4a8 - main - libc: Add missing kill_dependency macro

Hey,

I took another look and dug a bit deeper to make sure whether we
should adopt GCC’s form here, and I still think we should stick with
the current one.

First, although I still need to investigate further, I doubt it adds any
optimisation benefits, nor would omitting it incur a penalty.

More importantly, what we currently have fully conforms to the
§7.17.3.1 and is therefore in its most portable form. There is also
ongoing work (e.g. N3607) to retire `memory_order_consume` and
obsolete `kill_dependency`, with the proposed wording being that
the macro “has no other effect than its result”, which is essentially
just `(y)`, right? So presumably Clang's own `<stdatomic.h>` uses
`(y)` for the same sort of reasons.

However, I’m happy to discuss it further, and please do correct me
if you have data suggesting otherwise. In the meantime, I’ll do a bit
more research and will keep you posted if I find anything else.

Cheers,
Faraz