On Thu, 26 Nov 2020 at 11:29, <marcandre.lureau@redhat.com> wrote:
>
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> Since commit efc6c07 ("configure: Add a test for the minimum compiler
> version"), QEMU explicitely depends on GCC >= 4.8.
>
> (clang >= 3.8 advertizes itself as GCC >= 4.2 compatible)
All clangs always have advertised themselves as gcc-4.2-compatible,
as far as I'm aware. 3.4 is the version we need to care about,
I think it probably supported __builtin_expect(). (A test
of the whole series with gcc 4.8 and clang 3.4 would confirm this.)
clang 3.4 also advertizes as gcc-4.2, thus we can safely remove that __builtin_expect() fallback (if it didn't have it, it would have failed for a long while)
I also checked the __builtin_expect() support with clang-3.4.2-9.el7.x86_64 from EPEL7 successfully.