Unifying the handling of storing and loading from safepoint stack

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
diff --git a/src/arm/macro-assembler-arm.h b/src/arm/macro-assembler-arm.h
index 354662da32a4384c294ef866f32c5f6752691424..06709f435484b767925027bc66013c7a50257704 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -240,12 +240,13 @@ class MacroAssembler: public Assembler {
   void PopSafepointRegisters();
   void PushSafepointRegistersAndDoubles();
   void PopSafepointRegistersAndDoubles();
-  void StoreToSafepointRegisterSlot(Register reg);
-  void StoreToSafepointRegistersAndDoublesSlot(Register reg);
-  void LoadFromSafepointRegisterSlot(Register reg);
-  static int SafepointRegisterStackIndex(int reg_code);
-  static MemOperand SafepointRegisterSlot(Register reg);
-  static MemOperand SafepointRegistersAndDoublesSlot(Register reg);
+  // Store value in register src in the safepoint stack slot for
+  // register dst.
+  void StoreToSafepointRegisterSlot(Register src, Register dst);
+  void StoreToSafepointRegistersAndDoublesSlot(Register src, Register dst);
+  // Load the value of the src register from its safepoint stack slot
+  // into register dst.
+  void LoadFromSafepointRegisterSlot(Register dst, Register src);
 
   // Load two consecutive registers with two consecutive memory locations.
   void Ldrd(Register dst1,
@@ -883,10 +884,19 @@ class MacroAssembler: public Assembler {
                            Register scratch1,
                            Register scratch2);
 
+  // Compute memory operands for safepoint stack slots.
+  static int SafepointRegisterStackIndex(int reg_code);
+  MemOperand SafepointRegisterSlot(Register reg);
+  MemOperand SafepointRegistersAndDoublesSlot(Register reg);
+
   bool generating_stub_;
   bool allow_stub_calls_;
   // This handle will be patched with the code object on installation.
   Handle<Object> code_object_;
+
+  // Needs access to SafepointRegisterStackIndex for optimized frame
+  // traversal.
+  friend class OptimizedFrame;
 };