Improve C11 compiler detection for atomics and related.

Author: viferga

cmake/CompileOptions.cmake

@@ -34,19 +34,19 @@ include(Portability)
 # Project options
 #
 
-# Test for GNU, Clang or ((Visual Studio C++ or Clang with MSVC backend) and Visual Studio 2022 or superior)
-if(("${CMAKE_C_COMPILER_ID}" STREQUAL "GNU") OR
-	("${CMAKE_C_COMPILER_ID}" STREQUAL "Clang") OR
-	("${CMAKE_C_COMPILER_ID}" STREQUAL "AppleClang") OR
+# Test for GNU 4.9+, Clang 3.6+ or ((Visual Studio C++ or Clang with MSVC backend) and Visual Studio 2022 or superior)
+if(("${CMAKE_C_COMPILER_ID}" STREQUAL "GNU" AND ${CMAKE_C_COMPILER_VERSION} VERSION_GREATER 4.9) OR
+	((("${CMAKE_C_COMPILER_ID}" STREQUAL "Clang") OR
+	("${CMAKE_C_COMPILER_ID}" STREQUAL "AppleClang")) AND AND ${CMAKE_C_COMPILER_VERSION} VERSION_GREATER 3.6) OR
 	(
 		(("${CMAKE_C_COMPILER_ID}" STREQUAL "MSVC") OR
 		(("${CMAKE_C_COMPILER_ID}" STREQUAL "Clang") AND ("${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "MSVC"))) AND
 		(MSVC_VERSION GREATER_EQUAL 1930)
 	)
 )
-	set(C_STANDARD 11) # TODO: Implement support for older standards
+	set(C_STANDARD 11)
 else()
-	set(C_STANDARD 99)
+	set(C_STANDARD 99) # TODO: Implement support for older standards
 endif()
 
 set(DEFAULT_PROJECT_OPTIONS

source/threading/include/threading/threading_atomic_win32.h

@@ -120,6 +120,8 @@ typedef LONG volatile atomic_flag;
 #define atomic_is_lock_free(obj) \
 	(sizeof(obj) <= 8 && __atomic_is_lock_free_power_of_2(sizeof(obj)))
 
+#undef __atomic_is_lock_free_power_of_2
+
 inline bool atomic_store_explicit8(CHAR volatile *obj, CHAR desired, memory_order order)
 {
 	if (order == memory_order_seq_cst)
@@ -335,6 +337,33 @@ inline bool atomic_compare_exchange64(LONG64 volatile *obj, LONG64 *expected, LO
 		(sizeof *(obj) == 8) ? _InterlockedAnd64((LONG64 volatile *)obj, (LONG64)(arg)) : \
 								 (abort(), 0))
 
+#define __atomic_compiler_barrier(order)  \
+	do                                    \
+	{                                     \
+		if (order > memory_order_consume) \
+		{                                 \
+			_ReadWriteBarrier();          \
+		}                                 \
+	} while (0)
+
+inline void atomic_thread_fence(memory_order order)
+{
+	__atomic_compiler_barrier(order);
+
+	if (order == memory_order_seq_cst)
+	{
+		MemoryBarrier();
+		__atomic_compiler_barrier(order);
+	}
+}
+
+inline void atomic_signal_fence(memory_order order)
+{
+	__atomic_compiler_barrier(order);
+}
+
+#undef __atomic_compiler_barrier
+
 #ifdef __cplusplus
 }
 #endif