Re: [GIT PULL] bitmap changes for v6.12-rc1

[Linus Torvalds]

On Fri, 27 Sept 2024 at 13:08, Yury Norov <yury.norov@xxxxxxxxx> wrote:
>
> I'll drop GENMASK_U128() part from the request and send v2 later today.

I took your pull request, because I _suspect_ the test for
CC_HAS_INT128 is historical.

I *think* all the gcc (and clang) versions we support has __int128
support on arm64.  It's not a new feature.

That said, I'm not *sure* about it. The fact that we have a test for
it in the arm64 Kconfig file may be because we actually have compilers
that don't support __int128. Or it might be due to entirely historical
reasons.

So my point was just that people who make use of this should really be
aware of this worry, and double-check.

GENMASK_U128() is not necessarily wrong. It's just that it's not
necessarily available everywhere (it most definitely isn't on most
32-bit targets, for example, but arm64 _may_ be always ok).

               Linus