Allow uncacheable identifiers to go generic.

BUG=v8:2867
R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23453019

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16481 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ic.cc

@@ -1719,7 +1719,8 @@ MaybeObject* StoreIC::Store(State state,
     // Strict mode doesn't allow setting non-existent global property.
     return ReferenceError("not_defined", name);
   } else if (FLAG_use_ic &&
-             (lookup.IsNormal() ||
+             (!name->IsCacheable(isolate()) ||
+              lookup.IsNormal() ||
               (lookup.IsField() && lookup.CanHoldValue(value)))) {
     Handle<Code> stub = strict_mode == kStrictMode
         ? generic_stub_strict() : generic_stub();

src/objects.cc

@@ -1909,25 +1909,6 @@ MaybeObject* JSObject::AddFastPropertyUsingMap(Map* new_map,
 }
 
 
-static bool IsIdentifier(UnicodeCache* cache, Name* name) {
-  // Checks whether the buffer contains an identifier (no escape).
-  if (!name->IsString()) return false;
-  String* string = String::cast(name);
-  if (string->length() == 0) return false;
-  ConsStringIteratorOp op;
-  StringCharacterStream stream(string, &op);
-  if (!cache->IsIdentifierStart(stream.GetNext())) {
-    return false;
-  }
-  while (stream.HasMore()) {
-    if (!cache->IsIdentifierPart(stream.GetNext())) {
-      return false;
-    }
-  }
-  return true;
-}
-
-
 MaybeObject* JSObject::AddFastProperty(Name* name,
                                        Object* value,
                                        PropertyAttributes attributes,
@@ -1943,10 +1924,7 @@ MaybeObject* JSObject::AddFastProperty(Name* name,
   // hidden strings) and is not a real identifier.
   // Normalize the object if it will have too many fast properties.
   Isolate* isolate = GetHeap()->isolate();
-  if ((!name->IsSymbol() &&
-       !IsIdentifier(isolate->unicode_cache(), name) &&
-       name != isolate->heap()->hidden_string()) ||
-      TooManyFastProperties(store_mode)) {
+  if (!name->IsCacheable(isolate) || TooManyFastProperties(store_mode)) {
     MaybeObject* maybe_failure =
         NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0);
     if (maybe_failure->IsFailure()) return maybe_failure;
@@ -7955,6 +7933,32 @@ bool DescriptorArray::IsEqualTo(DescriptorArray* other) {
 #endif
 
 
+static bool IsIdentifier(UnicodeCache* cache, Name* name) {
+  // Checks whether the buffer contains an identifier (no escape).
+  if (!name->IsString()) return false;
+  String* string = String::cast(name);
+  if (string->length() == 0) return false;
+  ConsStringIteratorOp op;
+  StringCharacterStream stream(string, &op);
+  if (!cache->IsIdentifierStart(stream.GetNext())) {
+    return false;
+  }
+  while (stream.HasMore()) {
+    if (!cache->IsIdentifierPart(stream.GetNext())) {
+      return false;
+    }
+  }
+  return true;
+}
+
+
+bool Name::IsCacheable(Isolate* isolate) {
+  return IsSymbol() ||
+      IsIdentifier(isolate->unicode_cache(), this) ||
+      this == isolate->heap()->hidden_string();
+}
+
+
 bool String::LooksValid() {
   if (!Isolate::Current()->heap()->Contains(this)) return false;
   return true;

src/objects.h

@@ -7994,6 +7994,8 @@ class Name: public HeapObject {
   // Casting.
   static inline Name* cast(Object* obj);
 
+  bool IsCacheable(Isolate* isolate);
+
   DECLARE_PRINTER(Name)
 
   // Layout description.

test/mjsunit/regress/regress-store-uncacheable.js

@@ -0,0 +1,40 @@
+// Copyright 2013 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+function f() {
+  var o = {};
+  o["<abc>"] = 123;
+}
+
+f();
+f();
+f();
+%OptimizeFunctionOnNextCall(f);
+f();
+assertOptimized(f);