| Message ID | 20201210134752.780923-2-marcandre.lureau@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Remove GCC < 4.8 checks | expand |
On Thu, Dec 10, 2020 at 05:47:40PM +0400, marcandre.lureau@redhat.com wrote: > From: Philippe Mathieu-Daudé <philmd@redhat.com> > > Since commit efc6c070aca ("configure: Add a test for the > minimum compiler version") the minimum compiler version > required for GCC is 4.8, which has the GCC BZ#36793 bug fixed. > > We can safely remove the special case introduced in commit > a281ebc11a6 ("virtio: add missing mb() on notification"). > > With clang 3.4, __ATOMIC_RELAXED is defined, so the chunk to > remove (which is x86-specific), isn't reached either. > > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> > Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> > --- > include/qemu/atomic.h | 17 ----------------- > 1 file changed, 17 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index c1d211a351..8f4b3a80fb 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -241,23 +241,6 @@ #else /* __ATOMIC_RELAXED */ -/* - * We use GCC builtin if it's available, as that can use mfence on - * 32-bit as well, e.g. if built with -march=pentium-m. However, on - * i386 the spec is buggy, and the implementation followed it until - * 4.3 (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36793). - */ -#if defined(__i386__) || defined(__x86_64__) -#if !QEMU_GNUC_PREREQ(4, 4) -#if defined __x86_64__ -#define smp_mb() ({ asm volatile("mfence" ::: "memory"); (void)0; }) -#else -#define smp_mb() ({ asm volatile("lock; addl $0,0(%%esp) " ::: "memory"); (void)0; }) -#endif -#endif -#endif - - #ifdef __alpha__ #define smp_read_barrier_depends() asm volatile("mb":::"memory") #endif