diff --git a/src/util/u_atomic.h b/src/util/u_atomic.h index ec4569d24f7..ec77bb4d39c 100644 --- a/src/util/u_atomic.h +++ b/src/util/u_atomic.h @@ -340,4 +340,16 @@ static inline uint64_t p_atomic_xchg_64(uint64_t *v, uint64_t i) (assert(!"should not get here"), 0)) #endif +/* On x86 we can have sizeof(uint64_t) = 8 and _Alignof(uint64_t) = 4. causing split locks. The + * implementation does handle that correctly, but with an internal mutex. Extend the alignment to + * avoid this. + */ +#if __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_ATOMICS__) && defined(USE_GCC_ATOMIC_BUILTINS) +typedef int64_t __attribute__((aligned(_Alignof(_Atomic(int64_t))))) p_atomic_int64_t; +typedef uint64_t __attribute__((aligned(_Alignof(_Atomic(uint64_t))))) p_atomic_uint64_t; +#else +typedef int64_t p_atomic_int64_t; +typedef uint64_t p_atomic_uint64_t; +#endif + #endif /* U_ATOMIC_H */