Merge bleeding_edge r17376:17693.

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index b5046bd00190a46b4ae0aecc5c804b10989afc54..b3cb8ffc75dc3796ae288967b29c9c46f21a2e3e 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -352,6 +352,14 @@ class HGraph V8_FINAL : public ZoneObject {
   HConstant* GetConstantNull();
   HConstant* GetInvalidContext();
 
+  bool IsConstantUndefined(HConstant* constant);
+  bool IsConstant0(HConstant* constant);
+  bool IsConstant1(HConstant* constant);
+  bool IsConstantMinus1(HConstant* constant);
+  bool IsConstantTrue(HConstant* constant);
+  bool IsConstantFalse(HConstant* constant);
+  bool IsConstantHole(HConstant* constant);
+  bool IsConstantNull(HConstant* constant);
   bool IsStandardConstant(HConstant* constant);
 
   HBasicBlock* CreateBasicBlock();
@@ -366,6 +374,7 @@ class HGraph V8_FINAL : public ZoneObject {
   int GetMaximumValueID() const { return values_.length(); }
   int GetNextBlockID() { return next_block_id_++; }
   int GetNextValueID(HValue* value) {
+    ASSERT(!disallow_adding_new_values_);
     values_.Add(value, zone());
     return values_.length() - 1;
   }
@@ -373,6 +382,9 @@ class HGraph V8_FINAL : public ZoneObject {
     if (id >= 0 && id < values_.length()) return values_[id];
     return NULL;
   }
+  void DisallowAddingNewValues() {
+    disallow_adding_new_values_ = true;
+  }
 
   bool Optimize(BailoutReason* bailout_reason);
 
@@ -499,6 +511,7 @@ class HGraph V8_FINAL : public ZoneObject {
   int type_change_checksum_;
   int maximum_environment_size_;
   int no_side_effects_scope_count_;
+  bool disallow_adding_new_values_;
 
   DISALLOW_COPY_AND_ASSIGN(HGraph);
 };
@@ -1263,6 +1276,26 @@ class HGraphBuilder {
 
   HValue* BuildNumberToString(HValue* object, Handle<Type> type);
 
+  // Computes the size for a sequential string of the given length and encoding.
+  HValue* BuildSeqStringSizeFor(HValue* length,
+                                String::Encoding encoding);
+  // Copies characters from one sequential string to another.
+  void BuildCopySeqStringChars(HValue* src,
+                               HValue* src_offset,
+                               String::Encoding src_encoding,
+                               HValue* dst,
+                               HValue* dst_offset,
+                               String::Encoding dst_encoding,
+                               HValue* length);
+  // Both operands are non-empty strings.
+  HValue* BuildUncheckedStringAdd(HValue* left,
+                                  HValue* right,
+                                  PretenureFlag pretenure_flag);
+  // Both operands are strings.
+  HValue* BuildStringAdd(HValue* left,
+                         HValue* right,
+                         PretenureFlag pretenure_flag);
+
   HInstruction* BuildUncheckedMonomorphicElementAccess(
       HValue* checked_object,
       HValue* key,
@@ -1285,7 +1318,13 @@ class HGraphBuilder {
   HLoadNamedField* BuildLoadNamedField(HValue* object, HObjectAccess access);
   HInstruction* AddLoadNamedField(HValue* object, HObjectAccess access);
   HInstruction* BuildLoadStringLength(HValue* object, HValue* checked_value);
-  HStoreNamedField* AddStoreMapConstant(HValue* object, Handle<Map>);
+  HStoreNamedField* AddStoreMapConstant(HValue* object, Handle<Map> map);
+  HStoreNamedField* AddStoreMapConstantNoWriteBarrier(HValue* object,
+                                                      Handle<Map> map) {
+    HStoreNamedField* store_map = AddStoreMapConstant(object, map);
+    store_map->SkipWriteBarrier();
+    return store_map;
+  }
   HLoadNamedField* AddLoadElements(HValue* object);
 
   bool MatchRotateRight(HValue* left,