Implement clearing of CompareICs.

src/ic.cc

 // Copyright 2012 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
@@ skipping 334 matching lines @@
 
   switch (target->kind()) {
     case Code::LOAD_IC: return LoadIC::Clear(address, target);
     case Code::KEYED_LOAD_IC:
       return KeyedLoadIC::Clear(address, target);
     case Code::STORE_IC: return StoreIC::Clear(address, target);
     case Code::KEYED_STORE_IC:
       return KeyedStoreIC::Clear(address, target);
     case Code::CALL_IC: return CallIC::Clear(address, target);
     case Code::KEYED_CALL_IC:  return KeyedCallIC::Clear(address, target);
+    case Code::COMPARE_IC: return CompareIC::Clear(address, target);
     case Code::UNARY_OP_IC:
     case Code::BINARY_OP_IC:
-    case Code::COMPARE_IC:
     case Code::TO_BOOLEAN_IC:
       // Clearing these is tricky and does not
       // make any performance difference.
       return;
     default: UNREACHABLE();
   }
 }
 
 
 void CallICBase::Clear(Address address, Code* target) {
+  if (target->ic_state() == UNINITIALIZED) return;
   bool contextual = CallICBase::Contextual::decode(target->extra_ic_state());
-  State state = target->ic_state();
-  if (state == UNINITIALIZED) return;
   Code* code =
       Isolate::Current()->stub_cache()->FindCallInitialize(
           target->arguments_count(),
           contextual ? RelocInfo::CODE_TARGET_CONTEXT : RelocInfo::CODE_TARGET,
           target->kind());
   SetTargetAtAddress(address, code);
 }
 
 
 void KeyedLoadIC::Clear(Address address, Code* target) {
@@ skipping 22 matching lines @@
 
 void KeyedStoreIC::Clear(Address address, Code* target) {
   if (target->ic_state() == UNINITIALIZED) return;
   SetTargetAtAddress(address,
       (Code::GetStrictMode(target->extra_ic_state()) == kStrictMode)
         ? initialize_stub_strict()
         : initialize_stub());
 }
 
 
+void CompareIC::Clear(Address address, Code* target) {
+  // Only clear ICCompareStubs, we currently cannot clear generic CompareStubs.
+  if (target->major_key() != CodeStub::CompareIC) return;
+  if (target->compare_state() == UNINITIALIZED) return;

[Vyacheslav Egorov (Chromium), 2012/04/30 14:27:10]

We can limit clearing to those states that can retain objects.

[Michael Starzinger, 2012/05/02 11:07:23]

Done.

+  Token::Value op = CompareIC::ComputeOperation(target);
+  SetTargetAtAddress(address, initialize_stub(op));
+  PatchInlinedSmiCode(address, DISABLE_INLINED_SMI_CHECK);
+}
+
+
 static bool HasInterceptorGetter(JSObject* object) {
   return !object->GetNamedInterceptor()->getter()->IsUndefined();
 }
 
 
 static void LookupForRead(Handle<Object> object,
                           Handle<String> name,
                           LookupResult* lookup) {
   // Skip all the objects with named interceptors, but
   // without actual getter.
@@ skipping 1966 matching lines @@
              BinaryOpIC::GetName(previous_type),
              BinaryOpIC::GetName(type),
              BinaryOpIC::GetName(result_type),
              Token::Name(op));
     }
     BinaryOpIC ic(isolate);
     ic.patch(*code);
 
     // Activate inlined smi code.
     if (previous_type == BinaryOpIC::UNINITIALIZED) {
-      PatchInlinedSmiCode(ic.address());
+      PatchInlinedSmiCode(ic.address(), ENABLE_INLINED_SMI_CHECK);
     }
   }
 
   Handle<JSBuiltinsObject> builtins = Handle<JSBuiltinsObject>(
       isolate->thread_local_top()->context_->builtins(), isolate);
   Object* builtin = NULL;  // Initialization calms down the compiler.
   switch (op) {
     case Token::ADD:
       builtin = builtins->javascript_builtin(Builtins::ADD);
       break;
@@ skipping 40 matching lines @@
                                           ARRAY_SIZE(builtin_args),
                                           builtin_args,
                                           &caught_exception);
   if (caught_exception) {
     return Failure::Exception();
   }
   return *result;
 }
 
 
+Code* CompareIC::initialize_stub(Token::Value op) {

[Vyacheslav Egorov (Chromium), 2012/04/30 14:27:10]

I guess it should be called GetUnitializedStub() or something. (naming convetion
limits foo_bar methods to getters).

[Michael Starzinger, 2012/05/02 11:07:23]

Done. Renamed to GetRawUninitialized() to be in sync with the handlified version
a few lines below. We might consider renaming the stub accessors for LoadICs and
StoreICs as well at some point.

+  ICCompareStub stub(op, UNINITIALIZED);
+  Code* code = NULL;
+  CHECK(stub.FindCodeInCache(&code));
+  return code;
+}
+
+
 Handle<Code> CompareIC::GetUninitialized(Token::Value op) {
   ICCompareStub stub(op, UNINITIALIZED);
   return stub.GetCode();
 }
 
 
 CompareIC::State CompareIC::ComputeState(Code* target) {
   int key = target->major_key();
   if (key == CodeStub::Compare) return GENERIC;
   ASSERT(key == CodeStub::CompareIC);
   return static_cast<State>(target->compare_state());
 }
 
 
+Token::Value CompareIC::ComputeOperation(Code* target) {
+  ASSERT(target->major_key() == CodeStub::CompareIC);
+  return static_cast<Token::Value>(target->compare_operation());
+}
+
+
 const char* CompareIC::GetStateName(State state) {
   switch (state) {
     case UNINITIALIZED: return "UNINITIALIZED";
     case SMIS: return "SMIS";
     case HEAP_NUMBERS: return "HEAP_NUMBERS";
     case OBJECTS: return "OBJECTS";
     case KNOWN_OBJECTS: return "OBJECTS";
     case SYMBOLS: return "SYMBOLS";
     case STRINGS: return "STRINGS";
     case GENERIC: return "GENERIC";
@@ skipping 98 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal