This allows for slightly neater code when checking for success of a cmpxchg operation.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org> --- v4 (base-patches) - brought forward from ARM enabling patches - remove the un-needed extra temps --- include/qemu/atomic.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index 560b1af..aba2c23 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -152,6 +152,14 @@ _old; \ }) +#define atomic_bool_cmpxchg(ptr, old, new) \ + ({ \ + typeof(*ptr) _old = (old), _new = (new); \ + __atomic_compare_exchange(ptr, &_old, &_new, false, \ + __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); \ + }) + + /* Provide shorter names for GCC atomic builtins, return old value */ #define atomic_fetch_inc(ptr) __atomic_fetch_add(ptr, 1, __ATOMIC_SEQ_CST) #define atomic_fetch_dec(ptr) __atomic_fetch_sub(ptr, 1, __ATOMIC_SEQ_CST) @@ -356,6 +364,7 @@ #define atomic_fetch_and __sync_fetch_and_and #define atomic_fetch_or __sync_fetch_and_or #define atomic_cmpxchg __sync_val_compare_and_swap +#define atomic_bool_cmpxchg __sync_bool_compare_and_swap #define atomic_dec_fetch(ptr) __sync_sub_and_fetch(ptr, 1) -- 2.7.4