[Bug target/104189] enable 64-bit compare-and-swap on SPARC/Linux with V9

[glaubitz at physik dot fu-berlin.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104189

--- Comment #3 from John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> ---
(In reply to Eric Botcazou from comment #2)
> Created attachment 52272 [details]
> Tentative fix

Thanks a lot for the quick fix.

> This requires that the kernel preserves the full 64-bit registers even in
> 32-bit mode, like on Solaris.

I think that should be the case given that the 32-bit SPARC port in Debian has
been based on the SPARCV8+ baseline since 2007 [1].

Is there any way to verify this?

> [1] https://lists.debian.org/debian-devel-announce/2007/07/msg00006.html