Use untagged int32 values in evaluation of side-effect free expressions.

src/ia32/codegen-ia32.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 339 matching lines @@
   // Accessors
   inline bool is_eval();
   inline Scope* scope();
 
   // Generating deferred code.
   void ProcessDeferred();
 
   // State
   ControlDestination* destination() const { return state_->destination(); }
 
+  // Control of side-effect-free int32 expression compilation.
+  bool in_safe_int32_mode() { return in_safe_int32_mode_; }
+  void set_in_safe_int32_mode(bool value) { in_safe_int32_mode_ = value; }
+  bool safe_int32_mode_enabled() {
+    return FLAG_safe_int32_compiler && safe_int32_mode_enabled_;
+  }
+  void set_safe_int32_mode_enabled(bool value) {
+    safe_int32_mode_enabled_ = value;
+  }
+  void set_unsafe_bailout(BreakTarget* unsafe_bailout) {
+    unsafe_bailout_ = unsafe_bailout;
+  }
+
+  // Take the Result that is an untagged int32, and convert it to a tagged
+  // Smi or HeapNumber.  Remove the untagged_int32 flag from the result.
+  void ConvertInt32ResultToNumber(Result* value);
+
   // Track loop nesting level.
   int loop_nesting() const { return loop_nesting_; }
   void IncrementLoopNesting() { loop_nesting_++; }
   void DecrementLoopNesting() { loop_nesting_--; }
 
   // Node visitors.
   void VisitStatements(ZoneList<Statement*>* statements);
 
 #define DEF_VISIT(type) \
   void Visit##type(type* node);
@@ skipping 36 matching lines @@
 
   Operand ContextSlotOperandCheckExtensions(Slot* slot,
                                             Result tmp,
                                             JumpTarget* slow);
 
   // Expressions
   static Operand GlobalObject() {
     return ContextOperand(esi, Context::GLOBAL_INDEX);
   }
 
-  void LoadCondition(Expression* x,
+  void LoadCondition(Expression* expr,
                      ControlDestination* destination,
                      bool force_control);
   void Load(Expression* expr);
   void LoadGlobal();
   void LoadGlobalReceiver();
 
   // Generate code to push the value of an expression on top of the frame
   // and then spill the frame fully to memory.  This function is used
   // temporarily while the code generator is being transformed.
   void LoadAndSpill(Expression* expression);
 
+  // Evaluate an expression and place its value on top of the frame,
+  // using, or not using, the side-effect-free expression compiler.
+  void LoadInSafeInt32Mode(Expression* expr, BreakTarget* unsafe_bailout);
+  void LoadWithSafeInt32ModeDisabled(Expression* expr);
+
   // Read a value from a slot and leave it on top of the expression stack.
   Result LoadFromSlot(Slot* slot, TypeofState typeof_state);
   Result LoadFromSlotCheckForArguments(Slot* slot, TypeofState typeof_state);
   Result LoadFromGlobalSlotCheckExtensions(Slot* slot,
                                            TypeofState typeof_state,
                                            JumpTarget* slow);
 
   // Store the value on top of the expression stack into a slot, leaving the
   // value in place.
   void StoreToSlot(Slot* slot, InitState init_state);
@@ skipping 51 matching lines @@
 
   // Emit code to perform a binary operation on two likely smis.
   // The code to handle smi arguments is produced inline.
   // Consumes the Results *left and *right.
   Result LikelySmiBinaryOperation(Token::Value op,
                                   Result* left,
                                   Result* right,
                                   OverwriteMode overwrite_mode,
                                   bool no_negative_zero);
 
+
+  // Emit code to perform a binary operation on two untagged int32 values.
+  // The values are on top of the frame, and the result is pushed on the frame.
+  void Int32BinaryOperation(BinaryOperation* node);
+
+
   void Comparison(AstNode* node,
                   Condition cc,
                   bool strict,
                   ControlDestination* destination);
 
   // To prevent long attacker-controlled byte sequences, integer constants
   // from the JavaScript source are loaded in two parts if they are larger
   // than 17 bits.
   static const int kMaxSmiInlinedBits = 17;
   bool IsUnsafeSmi(Handle<Object> value);
@@ skipping 126 matching lines @@
   // Assembler
   MacroAssembler* masm_;  // to generate code
 
   CompilationInfo* info_;
 
   // Code generation state
   VirtualFrame* frame_;
   RegisterAllocator* allocator_;
   CodeGenState* state_;
   int loop_nesting_;
+  bool in_safe_int32_mode_;
+  bool safe_int32_mode_enabled_;
 
   // Jump targets.
   // The target of the return from the function.
   BreakTarget function_return_;
+  // The target of the bailout from a side-effect-free int32 subexpression.
+  BreakTarget* unsafe_bailout_;
 
   // True if the function return is shadowed (ie, jumping to the target
   // function_return_ does not jump to the true function return, but rather
   // to some unlinking code).
   bool function_return_is_shadowed_;
 
   // True when we are in code that expects the virtual frame to be fully
   // spilled.  Some virtual frame function are disabled in DEBUG builds when
   // called from spilled code, because they do not leave the virtual frame
   // in a spilled state.
@@ skipping 353 matching lines @@
     return ObjectBits::encode(object_.code()) |
            AddressBits::encode(addr_.code()) |
            ScratchBits::encode(scratch_.code());
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_CODEGEN_IA32_H_