Re-land Crankshaft-generated KeyedLoad stubs.

src/hydrogen-instructions.h

 // Copyright 2012 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 1926 matching lines @@
 
 class HJSArrayLength: public HTemplateInstruction<2> {
  public:
   HJSArrayLength(HValue* value, HValue* typecheck,
                  HType type = HType::Tagged()) {
     set_type(type);
     // The length of an array is stored as a tagged value in the array
     // object. It is guaranteed to be 32 bit integer, but it can be
     // represented as either a smi or heap number.
     SetOperandAt(0, value);
-    SetOperandAt(1, typecheck);
+    SetOperandAt(1, typecheck != NULL ? typecheck : value);

[Jakob Kummerow, 2012/12/11 14:05:54]

I could swear I've reviewed this change before... ah, yes:
https://codereview.chromium.org/11464027/

[danno, 2012/12/12 00:36:03]

Landed the other patch first, rebased on it.
On 2012/12/11 14:05:54, Jakob wrote:

     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnArrayLengths);
     SetGVNFlag(kDependsOnMaps);
   }
 
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
 
   virtual void PrintDataTo(StringStream* stream);
 
   HValue* value() { return OperandAt(0); }
-  HValue* typecheck() { return OperandAt(1); }
+  HValue* typecheck() {
+    ASSERT(HasTypeCheck());
+    return OperandAt(1);
+  }
+  bool HasTypeCheck() const { return OperandAt(0) != OperandAt(1); }
 
   DECLARE_CONCRETE_INSTRUCTION(JSArrayLength)
 
  protected:
   virtual bool DataEquals(HValue* other_raw) { return true; }
 
  private:
   virtual bool IsDeletable() const { return true; }
 };
 
@@ skipping 180 matching lines @@
   virtual bool IsDeletable() const { return true; }
 
   BuiltinFunctionId op_;
 };
 
 
 class HLoadElements: public HTemplateInstruction<2> {
  public:
   HLoadElements(HValue* value, HValue* typecheck) {
     SetOperandAt(0, value);
-    SetOperandAt(1, typecheck);
+    SetOperandAt(1, typecheck != NULL ? typecheck : value);
     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnElementsPointer);
   }
 
   HValue* value() { return OperandAt(0); }
-  HValue* typecheck() { return OperandAt(1); }
+  HValue* typecheck() {
+    ASSERT(HasTypeCheck());
+    return OperandAt(1);
+  }
+  bool HasTypeCheck() const { return OperandAt(0) != OperandAt(1); }
 
   virtual void PrintDataTo(StringStream* stream);
 
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(LoadElements)
 
  protected:
@@ skipping 2200 matching lines @@
     : public HTemplateInstruction<4>, public ArrayInstructionInterface {
  public:
   HLoadKeyed(HValue* obj,
              HValue* checked_key,
              HValue* dependency,
              ElementsKind elements_kind)
       : bit_field_(0) {
     bit_field_ = ElementsKindField::encode(elements_kind);
     SetOperandAt(0, obj);
     SetOperandAt(1, HBoundsCheck::ExtractUncheckedIndex(checked_key));
-    SetOperandAt(2, dependency);
+    SetOperandAt(2, dependency != NULL ? dependency : obj);
     SetOperandAt(3, checked_key);
 
     if (!is_external()) {
       // I can detect the case between storing double (holey and fast) and
       // smi/object by looking at elements_kind_.
       ASSERT(IsFastSmiOrObjectElementsKind(elements_kind) ||
              IsFastDoubleElementsKind(elements_kind));
 
       if (IsFastSmiOrObjectElementsKind(elements_kind)) {
         if (IsFastSmiElementsKind(elements_kind) &&
@@ skipping 21 matching lines @@
     }
 
     SetFlag(kUseGVN);
   }
 
   bool is_external() const {
     return IsExternalArrayElementsKind(elements_kind());
   }
   HValue* elements() { return OperandAt(0); }
   HValue* key() { return OperandAt(1); }
-  HValue* dependency() { return OperandAt(2); }
+  HValue* dependency() {
+    ASSERT(HasDependency());
+    return OperandAt(2);
+  }
+  bool HasDependency() const { return OperandAt(0) != OperandAt(2); }
   HValue* checked_key() { return OperandAt(3); }
   uint32_t index_offset() { return IndexOffsetField::decode(bit_field_); }
   void SetIndexOffset(uint32_t index_offset) {
     bit_field_ = IndexOffsetField::update(bit_field_, index_offset);
   }
   HValue* GetKey() { return key(); }
   void SetKey(HValue* key) { SetOperandAt(1, key); }
   bool IsDehoisted() { return IsDehoistedField::decode(bit_field_); }
   void SetDehoisted(bool is_dehoisted) {
     bit_field_ = IsDehoistedField::update(bit_field_, is_dehoisted);
@@ skipping 1027 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_