Reland 21774: Generate KeyedLoadGeneric with Hydrogen

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index d1f2372db689de8059d55f532d8ad26bf3bd661a..f1720f444247d83635c84d00a99cf2457ee0022e 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -6049,9 +6049,14 @@ class HObjectAccess V8_FINAL {
     return HObjectAccess(kMaps, JSObject::kMapOffset);
   }
 
-  static HObjectAccess ForMapInstanceSize() {
+  static HObjectAccess ForMapAsInteger32() {
+    return HObjectAccess(kMaps, JSObject::kMapOffset,
+                         Representation::Integer32());
+  }
+
+  static HObjectAccess ForMapInObjectProperties() {
     return HObjectAccess(kInobject,
-                         Map::kInstanceSizeOffset,
+                         Map::kInObjectPropertiesOffset,
                          Representation::UInteger8());
   }
 
@@ -6061,6 +6066,38 @@ class HObjectAccess V8_FINAL {
                          Representation::UInteger8());
   }
 
+  static HObjectAccess ForMapInstanceSize() {
+    return HObjectAccess(kInobject,
+                         Map::kInstanceSizeOffset,
+                         Representation::UInteger8());
+  }
+
+  static HObjectAccess ForMapBitField() {
+    return HObjectAccess(kInobject,
+                         Map::kBitFieldOffset,
+                         Representation::UInteger8());
+  }
+
+  static HObjectAccess ForMapBitField2() {
+    return HObjectAccess(kInobject,
+                         Map::kBitField2Offset,
+                         Representation::UInteger8());
+  }
+
+  static HObjectAccess ForNameHashField() {
+    return HObjectAccess(kInobject,
+                         Name::kHashFieldOffset,
+                         Representation::Integer32());
+  }
+
+  static HObjectAccess ForMapInstanceTypeAndBitField() {
+    STATIC_ASSERT((Map::kInstanceTypeOffset & 1) == 0);
+    STATIC_ASSERT(Map::kBitFieldOffset == Map::kInstanceTypeOffset + 1);
+    return HObjectAccess(kInobject,
+                         Map::kInstanceTypeOffset,
+                         Representation::UInteger16());
+  }
+
   static HObjectAccess ForPropertyCellValue() {
     return HObjectAccess(kInobject, PropertyCell::kValueOffset);
   }
@@ -6453,6 +6490,10 @@ class HLoadKeyed V8_FINAL
   bool HasDependency() const { return OperandAt(0) != OperandAt(2); }
   uint32_t base_offset() { return BaseOffsetField::decode(bit_field_); }
   void IncreaseBaseOffset(uint32_t base_offset) {
+    // The base offset is usually simply the size of the array header, except
+    // with dehoisting adds an addition offset due to a array index key
+    // manipulation, in which case it becomes (array header size +
+    // constant-offset-from-key * kPointerSize)
     base_offset += BaseOffsetField::decode(bit_field_);
     bit_field_ = BaseOffsetField::update(bit_field_, base_offset);
   }
@@ -6465,7 +6506,7 @@ class HLoadKeyed V8_FINAL
   void SetDehoisted(bool is_dehoisted) {
     bit_field_ = IsDehoistedField::update(bit_field_, is_dehoisted);
   }
-  ElementsKind elements_kind() const {
+  virtual ElementsKind elements_kind() const V8_OVERRIDE {
     return ElementsKindField::decode(bit_field_);
   }
   LoadKeyedHoleMode hole_mode() const {
@@ -6923,6 +6964,10 @@ class HStoreKeyed V8_FINAL
   ElementsKind elements_kind() const { return elements_kind_; }
   uint32_t base_offset() { return base_offset_; }
   void IncreaseBaseOffset(uint32_t base_offset) {
+    // The base offset is usually simply the size of the array header, except
+    // with dehoisting adds an addition offset due to a array index key
+    // manipulation, in which case it becomes (array header size +
+    // constant-offset-from-key * kPointerSize)
     base_offset_ += base_offset;
   }
   virtual int MaxBaseOffsetBits() {