Add Crankshaft support for smi-only elements

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 890 matching lines @@
   }
 
  private:
   ZoneList<HValue*> values_;
 };
 
 
 class HGoto: public HTemplateControlInstruction<1, 0> {
  public:
   explicit HGoto(HBasicBlock* target) {
-        SetSuccessorAt(0, target);
-      }
+    SetSuccessorAt(0, target);
+  }
 
   virtual Representation RequiredInputRepresentation(int index) const {
     return Representation::None();
   }
 
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(Goto)
 };
 
@@ skipping 2802 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(StoreNamedGeneric)
 
  private:
   Handle<String> name_;
   bool strict_mode_;
 };
 
 
 class HStoreKeyedFastElement: public HTemplateInstruction<3> {
  public:
-  HStoreKeyedFastElement(HValue* obj, HValue* key, HValue* val) {
+  enum ValueType { VALUE_IS_SMI, GENERIC_VALUE };
+  HStoreKeyedFastElement(HValue* obj, HValue* key, HValue* val,
+                         ValueType value_type = GENERIC_VALUE)

[danno, 2011/09/23 09:05:24]

Why not just use ElementKind here?

[Jakob Kummerow, 2011/09/26 11:30:32]

Done.

+      : value_type_(value_type) {
     SetOperandAt(0, obj);
     SetOperandAt(1, key);
     SetOperandAt(2, val);
     SetFlag(kChangesArrayElements);
   }
 
   virtual Representation RequiredInputRepresentation(int index) const {
     // The key is supposed to be Integer32.
     return index == 1
         ? Representation::Integer32()
         : Representation::Tagged();
   }
 
   HValue* object() { return OperandAt(0); }
   HValue* key() { return OperandAt(1); }
   HValue* value() { return OperandAt(2); }
+  bool value_is_smi() {
+    return value_type_ == VALUE_IS_SMI;
+  }
 
   bool NeedsWriteBarrier() {
-    return StoringValueNeedsWriteBarrier(value());
+    if (value_is_smi()) {
+      return false;
+    } else {
+      return StoringValueNeedsWriteBarrier(value());
+    }
   }
 
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(StoreKeyedFastElement)
+
+ private:
+  ValueType value_type_;
 };
 
 
 class HStoreKeyedFastDoubleElement: public HTemplateInstruction<3> {
  public:
   HStoreKeyedFastDoubleElement(HValue* elements,
                                HValue* key,
                                HValue* val) {
     SetOperandAt(0, elements);
     SetOperandAt(1, key);
@@ skipping 446 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_