diff --git a/CMakeLists.txt b/CMakeLists.txt index 350d5c747e..111e0cb0b1 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -3251,6 +3251,7 @@ elseif(PS2) gskit dmakit ps2_drivers + atomic ) elseif(N3DS) sdl_glob_sources("${SDL3_SOURCE_DIR}/src/main/n3ds/*.c") diff --git a/src/atomic/SDL_atomic.c b/src/atomic/SDL_atomic.c index e8a013c0aa..ee036fee8d 100644 --- a/src/atomic/SDL_atomic.c +++ b/src/atomic/SDL_atomic.c @@ -33,12 +33,18 @@ #include #endif -// The __atomic_load_n() intrinsic showed up in different times for different compilers. -#if defined(__GNUC__) && (__GNUC__ >= 5) +// The __atomic intrinsics showed up in different times for different compilers. +#if (defined(__GNUC__) && (__GNUC__ >= 5)) || (defined(__clang__) && defined(HAVE_GCC_ATOMICS)) #define HAVE_ATOMIC_LOAD_N 1 -#elif SDL_HAS_BUILTIN(__atomic_load_n) || (defined(__clang__) && defined(HAVE_GCC_ATOMICS)) +#define HAVE_ATOMIC_EXCHANGE_N 1 +#else +#if SDL_HAS_BUILTIN(__atomic_load_n) #define HAVE_ATOMIC_LOAD_N 1 #endif +#if SDL_HAS_BUILTIN(__atomic_exchange_n) +#define HAVE_ATOMIC_EXCHANGE_N 1 +#endif +#endif /* If any of the operations are not provided then we must emulate some @@ -174,7 +180,14 @@ int SDL_SetAtomicInt(SDL_AtomicInt *a, int v) #ifdef HAVE_MSC_ATOMICS SDL_COMPILE_TIME_ASSERT(atomic_set, sizeof(long) == sizeof(a->value)); return _InterlockedExchange((long *)&a->value, v); +#elif defined(HAVE_ATOMIC_EXCHANGE_N) + return __atomic_exchange_n(&a->value, v, __ATOMIC_SEQ_CST); #elif defined(HAVE_GCC_ATOMICS) + // __sync_lock_test_and_set() is designed for locking rather than a + // generic atomic exchange, so it only provides an acquire barrier + // and may not store the exact value on all architectures. We prefer + // __atomic_exchange_n() instead on all modern compilers. + __sync_synchronize(); return __sync_lock_test_and_set(&a->value, v); #elif defined(SDL_PLATFORM_SOLARIS) SDL_COMPILE_TIME_ASSERT(atomic_set, sizeof(uint_t) == sizeof(a->value)); @@ -193,7 +206,14 @@ Uint32 SDL_SetAtomicU32(SDL_AtomicU32 *a, Uint32 v) #ifdef HAVE_MSC_ATOMICS SDL_COMPILE_TIME_ASSERT(atomic_set, sizeof(long) == sizeof(a->value)); return _InterlockedExchange((long *)&a->value, v); +#elif defined(HAVE_ATOMIC_EXCHANGE_N) + return __atomic_exchange_n(&a->value, v, __ATOMIC_SEQ_CST); #elif defined(HAVE_GCC_ATOMICS) + // __sync_lock_test_and_set() is designed for locking rather than a + // generic atomic exchange, so it only provides an acquire barrier + // and may not store the exact value on all architectures. We prefer + // __atomic_exchange_n() instead on all modern compilers. + __sync_synchronize(); return __sync_lock_test_and_set(&a->value, v); #elif defined(SDL_PLATFORM_SOLARIS) SDL_COMPILE_TIME_ASSERT(atomic_set, sizeof(uint_t) == sizeof(a->value)); @@ -211,7 +231,14 @@ void *SDL_SetAtomicPointer(void **a, void *v) { #ifdef HAVE_MSC_ATOMICS return _InterlockedExchangePointer(a, v); +#elif defined(HAVE_ATOMIC_EXCHANGE_N) + return __atomic_exchange_n(a, v, __ATOMIC_SEQ_CST); #elif defined(HAVE_GCC_ATOMICS) + // __sync_lock_test_and_set() is designed for locking rather than a + // generic atomic exchange, so it only provides an acquire barrier + // and may not store the exact value on all architectures. We prefer + // __atomic_exchange_n() instead on all modern compilers. + __sync_synchronize(); return __sync_lock_test_and_set(a, v); #elif defined(SDL_PLATFORM_SOLARIS) return atomic_swap_ptr(a, v);