build: Add fallback for std::atomic_ref

Author: Exzap

src/Cafe/HW/Latte/Core/LatteCommandProcessor.cpp

@@ -509,20 +509,20 @@ LatteCMDPtr LatteCP_itMemWrite(LatteCMDPtr cmd, uint32 nWords)
 	if (word1 == 0x40000)
 	{
 		// write U32
-		std::atomic_ref<uint32be> atomicRef(*memPtr);
+		stdx::atomic_ref<uint32be> atomicRef(*memPtr);
 		atomicRef.store(word2);
 	}
 	else if (word1 == 0x00000)
 	{
 		// write U64
 		// note: The U32s are swapped here, but needs verification. Also, it seems like the two U32 halves are written independently and the U64 as a whole is not atomic -> investiagte
-		std::atomic_ref<uint64be> atomicRef(*(uint64be*)memPtr);
+		stdx::atomic_ref<uint64be> atomicRef(*(uint64be*)memPtr);
 		atomicRef.store(((uint64le)word2 << 32) | word3);
 	}
 	else if (word1 == 0x20000)
 	{
 		// write U64 (little endian)
-		std::atomic_ref<uint64le> atomicRef(*(uint64le*)memPtr);
+		stdx::atomic_ref<uint64le> atomicRef(*(uint64le*)memPtr);
 		atomicRef.store(((uint64le)word3 << 32) | word2);
 	}
 	else
@@ -543,7 +543,7 @@ LatteCMDPtr LatteCP_itEventWriteEOP(LatteCMDPtr cmd, uint32 nWords)
 
 	if (word0 == 0x504 && (word2&0x40000000)) // todo - figure out the flags
 	{
-		std::atomic_ref<uint64be> atomicRef(*(uint64be*)memory_getPointerFromPhysicalOffset(word1));
+		stdx::atomic_ref<uint64be> atomicRef(*(uint64be*)memory_getPointerFromPhysicalOffset(word1));
 		uint64 val = ((uint64)word4 << 32) | word3;
 		atomicRef.store(val);
 	}
@@ -554,8 +554,8 @@ LatteCMDPtr LatteCP_itEventWriteEOP(LatteCMDPtr cmd, uint32 nWords)
 	if (triggerInterrupt)
 	{
 		// todo - timestamp interrupt
-		TCL::TCLGPUNotifyNewRetirementTimestamp();
 	}
+	TCL::TCLGPUNotifyNewRetirementTimestamp();
 	return cmd;
 }
 

src/Cafe/OS/libs/TCL/TCL.cpp

@@ -30,7 +30,7 @@ namespace TCL
 		{
 			MEMPTR<uint32> b;
 			// this is the timestamp of the last buffer that was retired by the GPU
-			std::atomic_ref<uint64be> retireTimestamp(s_tclStatePPC->gpuRetireMarker);
+			stdx::atomic_ref<uint64be> retireTimestamp(s_tclStatePPC->gpuRetireMarker);
 			*timestampOut = retireTimestamp.load();
 			return 0;
 		}
@@ -48,7 +48,7 @@ namespace TCL
 		{
 			while ( true )
 			{
-				std::atomic_ref<uint64be> retireTimestamp(s_tclStatePPC->gpuRetireMarker);
+				stdx::atomic_ref<uint64be> retireTimestamp(s_tclStatePPC->gpuRetireMarker);
 				uint64 currentTimestamp = retireTimestamp.load();
 				if (currentTimestamp >= waitTs)
 					return 0;

src/Cafe/OS/libs/gx2/GX2_Command.cpp

@@ -114,7 +114,7 @@ namespace GX2
 	// current position of where the GPU is reading from. Updated via a memory write command submitted to the GPU
 	uint32 GX2Command_GetPoolGPUReadIndex()
 	{
-		std::atomic_ref<MEMPTR<uint32be>> _readPtr(s_commandState->gpuCommandReadPtr);
+		stdx::atomic_ref<MEMPTR<uint32be>> _readPtr(s_commandState->gpuCommandReadPtr);
 		MEMPTR<uint32be> currentReadPtr = _readPtr.load();
 		cemu_assert_debug(currentReadPtr);
 		return (uint32)(currentReadPtr.GetPtr() - s_commandState->commandPoolBase.GetPtr());
@@ -125,7 +125,7 @@ namespace GX2
 		uint64 retiredTimeStamp = GX2GetRetiredTimeStamp();
 		retiredTimeStamp += 1;
 		// but cant be higher than the submission timestamp
-		std::atomic_ref<uint64be> _lastSubmissionTime(s_commandState->lastSubmissionTime);
+		stdx::atomic_ref<uint64be> _lastSubmissionTime(s_commandState->lastSubmissionTime);
 		uint64 submissionTimeStamp = _lastSubmissionTime.load();
 		if (retiredTimeStamp > submissionTimeStamp)
 			retiredTimeStamp = submissionTimeStamp;
@@ -294,7 +294,7 @@ namespace GX2
 
 	uint64 GX2GetLastSubmittedTimeStamp()
 	{
-		std::atomic_ref<uint64be> _lastSubmissionTime(s_commandState->lastSubmissionTime);
+		stdx::atomic_ref<uint64be> _lastSubmissionTime(s_commandState->lastSubmissionTime);
 		return _lastSubmissionTime.load();
 	}
 

src/Common/precompiled.h

@@ -616,4 +616,34 @@ namespace stdx
 		scope_exit& operator=(scope_exit) = delete;
 		void release() { m_released = true;}
 	};
+
+	// Xcode 16 doesn't have std::atomic_ref support, so lets provide a minimalst reimplementation as a fallback
+#ifdef __cpp_lib_atomic_ref
+	#include <atomic>
+	template<typename T>
+	using atomic_ref = std::atomic_ref<T>;
+#else
+	template<typename T>
+	class atomic_ref
+	{
+		static_assert(std::is_trivially_copyable<T>::value, "atomic_ref requires trivially copyable types");
+
+	public:
+		using value_type = T;
+
+		explicit atomic_ref(T& obj) noexcept : ptr_(std::addressof(obj)) {}
+
+		T load(std::memory_order order = std::memory_order_seq_cst) const noexcept
+		{
+			return __atomic_load_n(ptr_, static_cast<int>(order));
+		}
+
+		void store(T desired, std::memory_order order = std::memory_order_seq_cst) const noexcept
+		{
+			__atomic_store_n(ptr_, desired, static_cast<int>(order));
+		}
+	private:
+		T* ptr_;
+	};
+#endif
 }