SPU: optimize GETLLAR (TSX)

Add an option "Accurate GETLLAR"

rpcs3/Emu/Cell/SPUThread.cpp

@@ -1155,9 +1155,8 @@ bool SPUThread::process_mfc_cmd(spu_mfc_cmd args)
 		if (is_polling)
 		{
 			rtime = vm::reservation_acquire(raddr, 128);
-			_mm_lfence();
 
-			while (vm::reservation_acquire(raddr, 128) == rtime && rdata == data)
+			while (rdata == data && vm::reservation_acquire(raddr, 128) == rtime)
 			{
 				if (test(state, cpu_flag::stop))
 				{
@@ -1170,7 +1169,26 @@ bool SPUThread::process_mfc_cmd(spu_mfc_cmd args)
 
 		if (LIKELY(g_use_rtm))
 		{
-			const u64 count = spu_getll_tx(raddr, rdata.data(), &rtime);
+			u64 count = 0;
+
+			if (g_cfg.core.spu_accurate_getllar)
+			{
+				count = spu_getll_tx(raddr, rdata.data(), &rtime);
+			}
+
+			if (count == 0)
+			{
+				for (++count;; count++, busy_wait(300))
+				{
+					rtime = vm::reservation_acquire(raddr, 128);
+					rdata = data;
+
+					if (LIKELY(vm::reservation_acquire(raddr, 128) == rtime))
+					{
+						break;
+					}
+				}
+			}
 
 			if (count > 9)
 			{
@@ -1180,10 +1198,26 @@ bool SPUThread::process_mfc_cmd(spu_mfc_cmd args)
 		else
 		{
 			auto& res = vm::reservation_lock(raddr, 128);
+
+			if (g_cfg.core.spu_accurate_getllar)
+			{
+				vm::_ref<atomic_t<u32>>(raddr) += 0;
+
+				// Full lock (heavyweight)
+				// TODO: vm::check_addr
+				vm::writer_lock lock(1);
+
 				rtime = res & ~1ull;
 				rdata = data;
 				res &= ~1ull;
 			}
+			else
+			{
+				rtime = res & ~1ull;
+				rdata = data;
+				res &= ~1ull;
+			}
+		}
 
 		// Copy to LS
 		_ref<decltype(rdata)>(args.lsa & 0x3ffff) = rdata;

rpcs3/Emu/System.h

@@ -321,6 +321,7 @@ struct cfg_root : cfg::node
 		cfg::_bool spu_loop_detection{this, "SPU loop detection", true}; //Try to detect wait loops and trigger thread yield
 		cfg::_bool spu_shared_runtime{this, "SPU Shared Runtime", true}; // Share compiled SPU functions between all threads
 		cfg::_enum<spu_block_size_type> spu_block_size{this, "SPU Block Size"};
+		cfg::_bool spu_accurate_getllar{this, "Accurate GETLLAR", false};
 
 		cfg::_enum<lib_loading_type> lib_loading{this, "Lib Loader", lib_loading_type::liblv2only};
 		cfg::_bool hook_functions{this, "Hook static functions"};