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authorPeter Maydell <peter.maydell@linaro.org>2013-10-22 10:58:41 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2013-11-21 17:38:57 +0100
commit392a4d5b9a1860aae82429d09321dac302d70396 (patch)
treed6fd58c07cec85254648c55168cca6daadc65c84 /include
parent7839ff593be03a7de3c6760e0b50c565ea751d36 (diff)
downloadhqemu-392a4d5b9a1860aae82429d09321dac302d70396.zip
hqemu-392a4d5b9a1860aae82429d09321dac302d70396.tar.gz
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>
Diffstat (limited to 'include')
-rw-r--r--include/qemu/atomic.h6
1 files changed, 3 insertions, 3 deletions
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index 0aa8913..492bce1 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))
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