Remove special ArrayLength handling already covered by JSObjectFieldAccessors

R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/153743005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19152 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -5481,18 +5481,6 @@ bool HOptimizedGraphBuilder::PropertyAccessInfo::CanAccessAsMonomorphic(
   STATIC_ASSERT(kMaxLoadPolymorphism == kMaxStorePolymorphism);
   if (types->length() > kMaxLoadPolymorphism) return false;
 
-  if (IsArrayLength()) {
-    bool is_fast = IsFastElementsKind(map()->elements_kind());
-    for (int i = 1; i < types->length(); ++i) {
-      Handle<Map> test_map = types->at(i);
-      if (test_map->instance_type() != JS_ARRAY_TYPE) return false;
-      if (IsFastElementsKind(test_map->elements_kind()) != is_fast) {
-        return false;
-      }
-    }
-    return true;
-  }
-
   HObjectAccess access = HObjectAccess::ForMap();  // bogus default
   if (GetJSObjectFieldAccess(&access)) {
     for (int i = 1; i < types->length(); ++i) {

src/hydrogen.h

@@ -2336,15 +2336,14 @@ class HOptimizedGraphBuilder : public HGraphBuilder, public AstVisitor {
     }
 
     bool GetJSObjectFieldAccess(HObjectAccess* access) {
-      if (IsArrayLength()) {
-        *access = HObjectAccess::ForArrayLength(map()->elements_kind());
-        return true;
-      }
       int offset;
       if (Accessors::IsJSObjectFieldAccessor<Type>(type_, name_, &offset)) {
         if (type_->Is(Type::String())) {
           ASSERT(name_->Equals(isolate()->heap()->length_string()));
           *access = HObjectAccess::ForStringLength();
+        } else if (type_->Is(Type::Array())) {
+          ASSERT(name_->Equals(isolate()->heap()->length_string()));
+          *access = HObjectAccess::ForArrayLength(map()->elements_kind());
         } else {
           *access = HObjectAccess::ForMapAndOffset(map(), offset);
         }
@@ -2368,11 +2367,6 @@ class HOptimizedGraphBuilder : public HGraphBuilder, public AstVisitor {
     Isolate* isolate() { return lookup_.isolate(); }
     CompilationInfo* current_info() { return builder_->current_info(); }
 
-    bool IsArrayLength() {
-      return map()->instance_type() == JS_ARRAY_TYPE &&
-          name_->Equals(isolate()->heap()->length_string());
-    }
-
     bool LoadResult(Handle<Map> map);
     bool LookupDescriptor();
     bool LookupInPrototypes();