Add extra flag for load-ic stubs in code cache.

This allows to distinguish between stubs compiled for the current object from
stubs compiled for objects that have the current object as a prototype.

BUG=v8:2593
R=verwaest@chromium.org

Review URL: https://chromiumcodereview.appspot.com/13552003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14132 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.h

@@ -4354,6 +4354,11 @@ class Code: public HeapObject {
     NONEXISTENT
   };
 
+  enum StubHolder {
+    OWN_STUB,
+    PROTOTYPE_STUB
+  };
+
   enum {
     NUMBER_OF_KINDS = LAST_IC_KIND + 1
   };
@@ -4549,6 +4554,8 @@ class Code: public HeapObject {
   class ExtraICStateKeyedAccessStoreMode:
       public BitField<KeyedAccessStoreMode, 1, 4> {};  // NOLINT
 
+  class ExtraICStateStubHolder: public BitField<StubHolder, 0, 1> {};
+
   static inline StrictModeFlag GetStrictMode(ExtraICState extra_ic_state) {
     return ExtraICStateStrictMode::decode(extra_ic_state);
   }
@@ -4565,6 +4572,10 @@ class Code: public HeapObject {
         ExtraICStateStrictMode::encode(strict_mode);
   }
 
+  static inline ExtraICState ComputeExtraICState(StubHolder stub_holder) {
+    return ExtraICStateStubHolder::encode(stub_holder);
+  }
+
   // Flags operations.
   static inline Flags ComputeFlags(
       Kind kind,

src/stub-cache.cc

@@ -123,10 +123,13 @@ Handle<Code> StubCache::FindIC(Handle<Name> name,
 
 
 Handle<Code> StubCache::FindHandler(Handle<Name> name,
+                                    Handle<JSObject> receiver,
                                     Handle<JSObject> stub_holder,
                                     Code::Kind kind,
-                                    Code::StubType type,
-                                    Code::ExtraICState extra_ic_state) {
+                                    Code::StubType type) {
+  Code::ExtraICState extra_ic_state = Code::ComputeExtraICState(
+      receiver.is_identical_to(stub_holder) ? Code::OWN_STUB
+                                            : Code::PROTOTYPE_STUB);
   ASSERT(type != Code::NORMAL);
   Code::Flags flags = Code::ComputeMonomorphicFlags(
       Code::STUB, extra_ic_state, type, kind);
@@ -194,7 +197,7 @@ Handle<Code> StubCache::ComputeLoadNonexistent(Handle<Name> name,
   // Compile the stub that is either shared for all names or
   // name specific if there are global objects involved.
   Handle<Code> handler = FindHandler(
-      cache_name, receiver, Code::LOAD_IC, Code::NONEXISTENT);
+      cache_name, receiver, receiver, Code::LOAD_IC, Code::NONEXISTENT);
   if (!handler.is_null()) return handler;
 
   LoadStubCompiler compiler(isolate_);
@@ -218,7 +221,7 @@ Handle<Code> StubCache::ComputeLoadField(Handle<Name> name,
 
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> stub = FindHandler(
-      name, stub_holder, Code::LOAD_IC, Code::FIELD);
+      name, receiver, stub_holder, Code::LOAD_IC, Code::FIELD);
   if (!stub.is_null()) return stub;
 
   LoadStubCompiler compiler(isolate_);
@@ -237,7 +240,7 @@ Handle<Code> StubCache::ComputeLoadCallback(
   ASSERT(v8::ToCData<Address>(callback->getter()) != 0);
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> stub = FindHandler(
-      name, stub_holder, Code::LOAD_IC, Code::CALLBACKS);
+      name, receiver, stub_holder, Code::LOAD_IC, Code::CALLBACKS);
   if (!stub.is_null()) return stub;
 
   LoadStubCompiler compiler(isolate_);
@@ -254,7 +257,7 @@ Handle<Code> StubCache::ComputeLoadViaGetter(Handle<Name> name,
                                              Handle<JSFunction> getter) {
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> stub = FindHandler(
-      name, stub_holder, Code::LOAD_IC, Code::CALLBACKS);
+      name, receiver, stub_holder, Code::LOAD_IC, Code::CALLBACKS);
   if (!stub.is_null()) return stub;
 
   LoadStubCompiler compiler(isolate_);
@@ -271,7 +274,7 @@ Handle<Code> StubCache::ComputeLoadConstant(Handle<Name> name,
                                             Handle<JSFunction> value) {
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> handler = FindHandler(
-      name, stub_holder, Code::LOAD_IC, Code::CONSTANT_FUNCTION);
+      name, receiver, stub_holder, Code::LOAD_IC, Code::CONSTANT_FUNCTION);
   if (!handler.is_null()) return handler;
 
   LoadStubCompiler compiler(isolate_);
@@ -287,7 +290,7 @@ Handle<Code> StubCache::ComputeLoadInterceptor(Handle<Name> name,
                                                Handle<JSObject> holder) {
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> stub = FindHandler(
-      name, stub_holder, Code::LOAD_IC, Code::INTERCEPTOR);
+      name, receiver, stub_holder, Code::LOAD_IC, Code::INTERCEPTOR);
   if (!stub.is_null()) return stub;
 
   LoadStubCompiler compiler(isolate_);
@@ -334,7 +337,7 @@ Handle<Code> StubCache::ComputeKeyedLoadField(Handle<Name> name,
 
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> stub = FindHandler(
-      name, stub_holder, Code::KEYED_LOAD_IC, Code::FIELD);
+      name, receiver, stub_holder, Code::KEYED_LOAD_IC, Code::FIELD);
   if (!stub.is_null()) return stub;
 
   KeyedLoadStubCompiler compiler(isolate_);
@@ -351,7 +354,8 @@ Handle<Code> StubCache::ComputeKeyedLoadConstant(Handle<Name> name,
                                                  Handle<JSFunction> value) {
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> handler = FindHandler(
-      name, stub_holder, Code::KEYED_LOAD_IC, Code::CONSTANT_FUNCTION);
+      name, receiver, stub_holder, Code::KEYED_LOAD_IC,
+      Code::CONSTANT_FUNCTION);
   if (!handler.is_null()) return handler;
 
   KeyedLoadStubCompiler compiler(isolate_);
@@ -366,7 +370,7 @@ Handle<Code> StubCache::ComputeKeyedLoadInterceptor(Handle<Name> name,
                                                     Handle<JSObject> holder) {
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> stub = FindHandler(
-      name, stub_holder, Code::KEYED_LOAD_IC, Code::INTERCEPTOR);
+      name, receiver, stub_holder, Code::KEYED_LOAD_IC, Code::INTERCEPTOR);
   if (!stub.is_null()) return stub;
 
   KeyedLoadStubCompiler compiler(isolate_);
@@ -384,7 +388,7 @@ Handle<Code> StubCache::ComputeKeyedLoadCallback(
     Handle<ExecutableAccessorInfo> callback) {
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> stub = FindHandler(
-      name, stub_holder, Code::KEYED_LOAD_IC, Code::CALLBACKS);
+      name, receiver, stub_holder, Code::KEYED_LOAD_IC, Code::CALLBACKS);
   if (!stub.is_null()) return stub;
 
   KeyedLoadStubCompiler compiler(isolate_);

src/stub-cache.h

@@ -85,10 +85,10 @@ class StubCache {
 
   Handle<Code> FindHandler(
       Handle<Name> name,
+      Handle<JSObject> receiver,
       Handle<JSObject> stub_holder,
       Code::Kind kind,
-      Code::StubType type,
-      Code::ExtraICState extra_state = Code::kNoExtraICState);
+      Code::StubType type);
 
   Handle<Code> ComputeMonomorphicIC(Handle<JSObject> receiver,
                                     Handle<Code> handler,

test/mjsunit/regress/regress-2593.js

+// 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: --expose_gc
+
+p1 =  { };
+p2 =  { };
+p3 =  { x : 1 };
+p2.__proto__ = p3
+p1.__proto__ = p2
+
+// Normalize p1.
+p1.z = 1
+delete p1.z
+
+// Make sure all objects are in old space.
+for (var i = 0; i < 10; i++) gc();
+
+function f2() {
+  p2.x;
+}
+
+function f1() {
+  return p1.x;
+}
+
+// Create load stub in p2.
+for (var i = 0; i < 10; i++) f2();
+
+// Create load stub in p2 for p1.
+for (var i = 0; i < 10; i++) f1();
+
+assertEquals(1, f1());
+
+p2.x = 2;
+
+assertEquals(2, f1());