diff options
Diffstat (limited to 'src/util')
| -rw-r--r-- | src/util/u_atomic.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/src/util/u_atomic.h b/src/util/u_atomic.h index 8675903..2a5bbae 100644 --- a/src/util/u_atomic.h +++ b/src/util/u_atomic.h @@ -36,6 +36,20 @@ #define PIPE_ATOMIC "GCC Sync Intrinsics" +#if defined(USE_GCC_ATOMIC_BUILTINS) + +/* The builtins with explicit memory model are available since GCC 4.7. */ +#define p_atomic_set(_v, _i) __atomic_store_n((_v), (_i), __ATOMIC_RELEASE) +#define p_atomic_read(_v) __atomic_load_n((_v), __ATOMIC_ACQUIRE) +#define p_atomic_dec_zero(v) (__atomic_sub_fetch((v), 1, __ATOMIC_ACQ_REL) == 0) +#define p_atomic_inc(v) (void) __atomic_add_fetch((v), 1, __ATOMIC_ACQ_REL) +#define p_atomic_dec(v) (void) __atomic_sub_fetch((v), 1, __ATOMIC_ACQ_REL) +#define p_atomic_add(v, i) (void) __atomic_add_fetch((v), (i), __ATOMIC_ACQ_REL) +#define p_atomic_inc_return(v) __atomic_add_fetch((v), 1, __ATOMIC_ACQ_REL) +#define p_atomic_dec_return(v) __atomic_sub_fetch((v), 1, __ATOMIC_ACQ_REL) + +#else + #define p_atomic_set(_v, _i) (*(_v) = (_i)) #define p_atomic_read(_v) (*(_v)) #define p_atomic_dec_zero(v) (__sync_sub_and_fetch((v), 1) == 0) @@ -44,6 +58,13 @@ #define p_atomic_add(v, i) (void) __sync_add_and_fetch((v), (i)) #define p_atomic_inc_return(v) __sync_add_and_fetch((v), 1) #define p_atomic_dec_return(v) __sync_sub_and_fetch((v), 1) + +#endif + +/* There is no __atomic_* compare and exchange that returns the current value. + * Also, GCC 5.4 seems unable to optimize a compound statement expression that + * uses an additional stack variable with __atomic_compare_exchange[_n]. + */ #define p_atomic_cmpxchg(v, old, _new) \ __sync_val_compare_and_swap((v), (old), (_new)) |