PPC: [Atomics] Make Atomics.exchange a builtin using TF

src/ppc/simulator-ppc.h

Index: src/ppc/simulator-ppc.h
diff --git a/src/ppc/simulator-ppc.h b/src/ppc/simulator-ppc.h
index 91e7f05ea5433b09fcb93b3287e323e1a644dc76..0c23b04a37964dd8c3051cbd3082951c3af82391 100644
--- a/src/ppc/simulator-ppc.h
+++ b/src/ppc/simulator-ppc.h
@@ -289,19 +289,25 @@ class Simulator {
 
   // Read and write memory.
   inline uint8_t ReadBU(intptr_t addr);
+  inline uint8_t ReadExBU(intptr_t addr);
   inline int8_t ReadB(intptr_t addr);
   inline void WriteB(intptr_t addr, uint8_t value);
+  inline int WriteExB(intptr_t addr, uint8_t value);
   inline void WriteB(intptr_t addr, int8_t value);
 
   inline uint16_t ReadHU(intptr_t addr, Instruction* instr);
+  inline uint16_t ReadExHU(intptr_t addr, Instruction* instr);
   inline int16_t ReadH(intptr_t addr, Instruction* instr);
   // Note: Overloaded on the sign of the value.
   inline void WriteH(intptr_t addr, uint16_t value, Instruction* instr);
+  inline int WriteExH(intptr_t addr, uint16_t value, Instruction* instr);
   inline void WriteH(intptr_t addr, int16_t value, Instruction* instr);
 
   inline uint32_t ReadWU(intptr_t addr, Instruction* instr);
+  inline uint32_t ReadExWU(intptr_t addr, Instruction* instr);
   inline int32_t ReadW(intptr_t addr, Instruction* instr);
   inline void WriteW(intptr_t addr, uint32_t value, Instruction* instr);
+  inline int WriteExW(intptr_t addr, uint32_t value, Instruction* instr);
   inline void WriteW(intptr_t addr, int32_t value, Instruction* instr);
 
   intptr_t* ReadDW(intptr_t addr);
@@ -311,7 +317,8 @@ class Simulator {
   void SetCR0(intptr_t result, bool setSO = false);
   void ExecuteBranchConditional(Instruction* instr, BCType type);
   void ExecuteExt1(Instruction* instr);
-  bool ExecuteExt2_10bit(Instruction* instr);
+  bool ExecuteExt2_10bit_part1(Instruction* instr);
+  bool ExecuteExt2_10bit_part2(Instruction* instr);
   bool ExecuteExt2_9bit_part1(Instruction* instr);
   bool ExecuteExt2_9bit_part2(Instruction* instr);
   void ExecuteExt2_5bit(Instruction* instr);
@@ -398,6 +405,84 @@ class Simulator {
     char* desc;
   };
   StopCountAndDesc watched_stops_[kNumOfWatchedStops];
+
+  // Syncronization primitives. See ARM DDI 0406C.b, A2.9.
+  enum class MonitorAccess {
+    Open,
+    Exclusive,
+  };
+
+  enum class TransactionSize {
+    None = 0,
+    Byte = 1,
+    HalfWord = 2,
+    Word = 4,
+  };
+
+  class LocalMonitor {
+   public:
+    LocalMonitor();
+
+    // These functions manage the state machine for the local monitor, but do
+    // not actually perform loads and stores. NotifyStoreExcl only returns
+    // true if the exclusive store is allowed; the global monitor will still
+    // have to be checked to see whether the memory should be updated.
+    void NotifyLoad(int32_t addr);
+    void NotifyLoadExcl(int32_t addr, TransactionSize size);
+    void NotifyStore(int32_t addr);
+    bool NotifyStoreExcl(int32_t addr, TransactionSize size);
+
+   private:
+    void Clear();
+
+    MonitorAccess access_state_;
+    int32_t tagged_addr_;
+    TransactionSize size_;
+  };
+
+  class GlobalMonitor {
+   public:
+    GlobalMonitor();
+
+    class Processor {
+     public:
+      Processor();
+
+     private:
+      friend class GlobalMonitor;
+      // These functions manage the state machine for the global monitor, but do
+      // not actually perform loads and stores.
+      void Clear_Locked();
+      void NotifyLoadExcl_Locked(int32_t addr);
+      void NotifyStore_Locked(int32_t addr, bool is_requesting_processor);
+      bool NotifyStoreExcl_Locked(int32_t addr, bool is_requesting_processor);
+
+      MonitorAccess access_state_;
+      int32_t tagged_addr_;
+      Processor* next_;
+      Processor* prev_;
+    };
+
+    // Exposed so it can be accessed by Simulator::{Read,Write}Ex*.
+    base::Mutex mutex;
+
+    void NotifyLoadExcl_Locked(int32_t addr, Processor* processor);
+    void NotifyStore_Locked(int32_t addr, Processor* processor);
+    bool NotifyStoreExcl_Locked(int32_t addr, Processor* processor);
+
+    // Called when the simulator is destroyed.
+    void RemoveProcessor(Processor* processor);
+
+   private:
+    bool IsProcessorInLinkedList_Locked(Processor* processor) const;
+    void PrependProcessor_Locked(Processor* processor);
+
+    Processor* head_;
+  };
+
+  LocalMonitor local_monitor_;
+  GlobalMonitor::Processor global_monitor_processor_;
+  static base::LazyInstance<GlobalMonitor>::type global_monitor_;
 };