diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2013-10-22 10:58:41 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2013-11-21 17:38:57 +0100 |
| commit | 392a4d5b9a1860aae82429d09321dac302d70396 (patch) | |
| tree | d6fd58c07cec85254648c55168cca6daadc65c84 | |
| parent | 7839ff593be03a7de3c6760e0b50c565ea751d36 (diff) | |
atomic.h: Fix build with clang
clang defines __ATOMIC_SEQ_CST but its implementation of the
__atomic_exchange() builtin differs from that of gcc. Move the
__clang__ branch of the ifdef ladder to the top and fix its
implementation (there is no such builtin as __sync_exchange),
so we can compile with clang again.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | include/qemu/atomic.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index 0aa8913301..492bce1c1b 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -168,14 +168,14 @@ #endif #ifndef atomic_xchg -#ifdef __ATOMIC_SEQ_CST +#if defined(__clang__) +#define atomic_xchg(ptr, i) __sync_swap(ptr, i) +#elif defined(__ATOMIC_SEQ_CST) #define atomic_xchg(ptr, i) ({ \ typeof(*ptr) _new = (i), _old; \ __atomic_exchange(ptr, &_new, &_old, __ATOMIC_SEQ_CST); \ _old; \ }) -#elif defined __clang__ -#define atomic_xchg(ptr, i) __sync_exchange(ptr, i) #else /* __sync_lock_test_and_set() is documented to be an acquire barrier only. */ #define atomic_xchg(ptr, i) (smp_mb(), __sync_lock_test_and_set(ptr, i)) |