Prevent deopt on double value assignment to typed arrays

src/hydrogen-instructions.h

 // Copyright 2011 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 83 matching lines @@
   V(CompareMap)                                \
   V(CompareSymbolEq)                           \
   V(Constant)                                  \
   V(Context)                                   \
   V(DeleteProperty)                            \
   V(Deoptimize)                                \
   V(Div)                                       \
   V(EnterInlined)                              \
   V(ExternalArrayLength)                       \
   V(FixedArrayLength)                          \
+  V(ToInt32)                                   \
   V(ForceRepresentation)                       \
   V(FunctionLiteral)                           \
   V(GetCachedArrayIndex)                       \
   V(GlobalObject)                              \
   V(GlobalReceiver)                            \
   V(Goto)                                      \
   V(HasInstanceType)                           \
   V(HasCachedArrayIndex)                       \
   V(In)                                        \
   V(InstanceOf)                                \
@@ skipping 870 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(AbnormalExit)
 };
 
 
 class HUnaryOperation: public HTemplateInstruction<1> {
  public:
   explicit HUnaryOperation(HValue* value) {
     SetOperandAt(0, value);
   }
 
+  static HUnaryOperation* cast(HValue* value) {
+    return reinterpret_cast<HUnaryOperation*>(value);
+  }
+
+  virtual bool CanTruncateToInt32() const {
+    return CheckFlag(kTruncatingToInt32);
+  }
+
   HValue* value() { return OperandAt(0); }
   virtual void PrintDataTo(StringStream* stream);
 };
 
 
 class HThrow: public HUnaryOperation {
  public:
   explicit HThrow(HValue* value) : HUnaryOperation(value) {
     SetAllSideEffects();
   }
@@ skipping 44 matching lines @@
   }
 
   virtual HValue* EnsureAndPropagateNotMinusZero(BitVector* visited);
 
   Representation from() const { return from_; }
   Representation to() const { return representation(); }
   virtual Representation RequiredInputRepresentation(int index) const {
     return from_;
   }
 
-  bool CanTruncateToInt32() const { return CheckFlag(kTruncatingToInt32); }
-
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(Change)
 
  protected:
   virtual bool DataEquals(HValue* other) {
     if (!other->IsChange()) return false;
     HChange* change = HChange::cast(other);
     return value() == change->value()
         && to().Equals(change->to());
@@ skipping 37 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(ClampToUint8)
 
  protected:
   virtual bool DataEquals(HValue* other) { return true; }
 
  private:
   Representation input_rep_;
 };
 
 
+class HToInt32: public HUnaryOperation {
+ public:
+  explicit HToInt32(HValue* value)
+      : HUnaryOperation(value) {
+    set_representation(Representation::Integer32());
+    SetFlag(kUseGVN);
+  }
+
+  virtual Representation RequiredInputRepresentation(int index) const {
+    return Representation::None();
+  }
+
+  virtual bool CanTruncateToInt32() const {
+    return true;
+  }
+
+  virtual HValue* Canonicalize() {
+    if (value()->representation().IsInteger32()) {
+      return value();
+    } else {
+      return this;
+    }
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(ToInt32)
+
+ protected:
+  virtual bool DataEquals(HValue* other) { return true; }
+};
+
+
 class HSimulate: public HInstruction {
  public:
   HSimulate(int ast_id, int pop_count)
       : ast_id_(ast_id),
         pop_count_(pop_count),
         values_(2),
         assigned_indexes_(2) {}
   virtual ~HSimulate() {}
 
   virtual void PrintDataTo(StringStream* stream);
@@ skipping 2835 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_