Make sure we don't flush the pregenerated stubs, since they need

to be always present, so that we can call them from other stubs
without trying to generate stubs while we are generating stubs.
Review URL: http://codereview.chromium.org/8052029

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9459 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/code-stubs-arm.cc

@@ -877,8 +877,8 @@ bool WriteInt32ToHeapNumberStub::IsPregenerated() {
 void WriteInt32ToHeapNumberStub::GenerateFixedRegStubsAheadOfTime() {
   WriteInt32ToHeapNumberStub stub1(r1, r0, r2);
   WriteInt32ToHeapNumberStub stub2(r2, r0, r3);
-  Handle<Code> code1 = stub1.GetCode();
-  Handle<Code> code2 = stub2.GetCode();
+  Handle<Code> code1 = stub1.GetCode()->set_is_pregenerated(true);
+  Handle<Code> code2 = stub2.GetCode()->set_is_pregenerated(true);
 }
 
 
@@ -3413,7 +3413,7 @@ void CodeStub::GenerateStubsAheadOfTime() {
 
 void CodeStub::GenerateFPStubs() {
   CEntryStub save_doubles(1, kSaveFPRegs);
-  Handle<Code> code = save_doubles.GetCode();
+  Handle<Code> code = save_doubles.GetCode()->set_is_pregenerated(true);
   code->GetIsolate()->set_fp_stubs_generated(true);
 }
 
@@ -6877,9 +6877,9 @@ bool RecordWriteStub::IsPregenerated() {
 
 void StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime() {
   StoreBufferOverflowStub stub1(kDontSaveFPRegs);
-  stub1.GetCode();
+  stub1.GetCode()->set_is_pregenerated(true);
   StoreBufferOverflowStub stub2(kSaveFPRegs);
-  stub2.GetCode();
+  stub2.GetCode()->set_is_pregenerated(true);
 }
 
 
@@ -6892,7 +6892,7 @@ void RecordWriteStub::GenerateFixedRegStubsAheadOfTime() {
                          entry->address,
                          entry->action,
                          kDontSaveFPRegs);
-    stub.GetCode();
+    stub.GetCode()->set_is_pregenerated(true);
   }
 }
 

src/ia32/code-stubs-ia32.cc

@@ -4424,6 +4424,7 @@ void CodeStub::GenerateStubsAheadOfTime() {
 void CodeStub::GenerateFPStubs() {
   CEntryStub save_doubles(1, kSaveFPRegs);
   Handle<Code> code = save_doubles.GetCode();
+  code->set_is_pregenerated(true);
   code->GetIsolate()->set_fp_stubs_generated(true);
 }
 
@@ -6667,7 +6668,7 @@ struct AheadOfTimeWriteBarrierStubList kAheadOfTime[] = {
   { ebx, eax, edi, EMIT_REMEMBERED_SET },
   // Used in CompileArrayPushCall.
   { ebx, ecx, edx, EMIT_REMEMBERED_SET },
-  // Used in CompileStoreGlobal.
+  // Used in CompileStoreGlobal and CallFunctionStub.
   { ebx, ecx, edx, OMIT_REMEMBERED_SET },
   // Used in StoreStubCompiler::CompileStoreField and
   // KeyedStoreStubCompiler::CompileStoreField via GenerateStoreField.
@@ -6704,12 +6705,12 @@ bool RecordWriteStub::IsPregenerated() {
 
 void StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime() {
   StoreBufferOverflowStub stub1(kDontSaveFPRegs);
-  stub1.GetCode();
+  stub1.GetCode()->set_is_pregenerated(true);
 
   CpuFeatures::TryForceFeatureScope scope(SSE2);
   if (CpuFeatures::IsSupported(SSE2)) {
     StoreBufferOverflowStub stub2(kSaveFPRegs);
-    stub2.GetCode();
+    stub2.GetCode()->set_is_pregenerated(true);
   }
 }
 
@@ -6723,7 +6724,7 @@ void RecordWriteStub::GenerateFixedRegStubsAheadOfTime() {
                          entry->address,
                          entry->action,
                          kDontSaveFPRegs);
-    stub.GetCode();
+    stub.GetCode()->set_is_pregenerated(true);
   }
 }
 

src/isolate.cc

@@ -1768,7 +1768,7 @@ bool Isolate::Init(Deserializer* des) {
   // If we are deserializing, read the state into the now-empty heap.
   if (des != NULL) {
     des->Deserialize();
-    stub_cache_->Clear();
+    stub_cache_->Initialize(true);
   }
 
   // Deserializing may put strange things in the root array's copy of the

src/objects-inl.h

@@ -2935,6 +2935,19 @@ void Code::set_major_key(int major) {
 }
 
 
+bool Code::is_pregenerated() {
+  return kind() == STUB && IsPregeneratedField::decode(flags());
+}
+
+
+void Code::set_is_pregenerated(bool value) {
+  ASSERT(kind() == STUB);
+  Flags f = flags();
+  f = static_cast<Flags>(IsPregeneratedField::update(f, value));
+  set_flags(f);
+}
+
+
 bool Code::optimizable() {
   ASSERT(kind() == FUNCTION);
   return READ_BYTE_FIELD(this, kOptimizableOffset) == 1;

src/objects.h

@@ -3657,6 +3657,11 @@ class Code: public HeapObject {
   inline int major_key();
   inline void set_major_key(int value);
 
+  // For stubs, tells whether they should always exist, so that they can be
+  // called from other stubs.
+  inline bool is_pregenerated();
+  inline void set_is_pregenerated(bool value);
+
   // [optimizable]: For FUNCTION kind, tells if it is optimizable.
   inline bool optimizable();
   inline void set_optimizable(bool value);
@@ -3880,6 +3885,7 @@ class Code: public HeapObject {
   class KindField: public BitField<Kind, 7, 4> {};
   class CacheHolderField: public BitField<InlineCacheHolderFlag, 11, 1> {};
   class ExtraICStateField: public BitField<ExtraICState, 12, 2> {};
+  class IsPregeneratedField: public BitField<bool, 14, 1> {};
 
   // Signed field cannot be encoded using the BitField class.
   static const int kArgumentsCountShift = 14;

src/stub-cache.cc

@@ -55,7 +55,15 @@ void StubCache::Initialize(bool create_heap_objects) {
   ASSERT(IsPowerOf2(kSecondaryTableSize));
   if (create_heap_objects) {
     HandleScope scope;
-    Clear();
+    Code* empty = isolate_->builtins()->builtin(Builtins::kIllegal);
+    for (int i = 0; i < kPrimaryTableSize; i++) {
+      primary_[i].key = heap()->empty_string();
+      primary_[i].value = empty;
+    }
+    for (int j = 0; j < kSecondaryTableSize; j++) {
+      secondary_[j].key = heap()->empty_string();
+      secondary_[j].value = empty;
+    }
   }
 }
 
@@ -1099,15 +1107,20 @@ MaybeObject* StubCache::ComputeCallDebugPrepareStepIn(
 
 
 void StubCache::Clear() {
+  Code* empty = isolate_->builtins()->builtin(Builtins::kIllegal);
   for (int i = 0; i < kPrimaryTableSize; i++) {
-    primary_[i].key = heap()->empty_string();
-    primary_[i].value = isolate_->builtins()->builtin(
-        Builtins::kIllegal);
+    Code* code = primary_[i].value;
+    if (code != empty && !code->is_pregenerated()) {
+      primary_[i].key = heap()->empty_string();
+      primary_[i].value = empty;
+    }
   }
   for (int j = 0; j < kSecondaryTableSize; j++) {
-    secondary_[j].key = heap()->empty_string();
-    secondary_[j].value = isolate_->builtins()->builtin(
-        Builtins::kIllegal);
+    Code* code = secondary_[j].value;
+    if (code != empty && !code->is_pregenerated()) {
+      secondary_[j].key = heap()->empty_string();
+      secondary_[j].value = empty;
+    }
   }
 }
 

src/x64/code-stubs-x64.cc

@@ -3376,7 +3376,7 @@ bool CEntryStub::IsPregenerated() {
 
 void CodeStub::GenerateStubsAheadOfTime() {
   CEntryStub save_doubles(1, kSaveFPRegs);
-  save_doubles.GetCode();
+  save_doubles.GetCode()->set_is_pregenerated(true);
   StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime();
   // It is important that the store buffer overflow stubs are generated first.
   RecordWriteStub::GenerateFixedRegStubsAheadOfTime();
@@ -5616,9 +5616,9 @@ bool RecordWriteStub::IsPregenerated() {
 
 void StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime() {
   StoreBufferOverflowStub stub1(kDontSaveFPRegs);
-  stub1.GetCode();
+  stub1.GetCode()->set_is_pregenerated(true);
   StoreBufferOverflowStub stub2(kSaveFPRegs);
-  stub2.GetCode();
+  stub2.GetCode()->set_is_pregenerated(true);
 }
 
 
@@ -5631,7 +5631,7 @@ void RecordWriteStub::GenerateFixedRegStubsAheadOfTime() {
                          entry->address,
                          entry->action,
                          kDontSaveFPRegs);
-    stub.GetCode();
+    stub.GetCode()->set_is_pregenerated(true);
   }
 }