Disable tracking of double fields during snapshot creation.

Follow-up to r18298.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/101123004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18909 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-codegen-arm.cc

@@ -4061,7 +4061,7 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
       __ SmiTst(value);
       DeoptimizeIf(eq, instr->environment());
     }
-  } else if (FLAG_track_double_fields && representation.IsDouble()) {
+  } else if (representation.IsDouble()) {
     ASSERT(transition.is_null());
     ASSERT(access.IsInobject());
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());

src/bootstrapper.cc

@@ -2556,12 +2556,31 @@ void Genesis::MakeFunctionInstancePrototypeWritable() {
 }
 
 
+class NoTrackDoubleFieldsForSerializerScope {
+ public:
+  NoTrackDoubleFieldsForSerializerScope() : flag_(FLAG_track_double_fields) {
+    if (Serializer::enabled()) {
+      // Disable tracking double fields because heap numbers treated as
+      // immutable by the serializer.
+      FLAG_track_double_fields = false;
+    }
+  }
+  ~NoTrackDoubleFieldsForSerializerScope() {
+    FLAG_track_double_fields = flag_;
+  }
+
+ private:
+  bool flag_;
+};
+
+
 Genesis::Genesis(Isolate* isolate,
                  Handle<Object> global_object,
                  v8::Handle<v8::ObjectTemplate> global_template,
                  v8::ExtensionConfiguration* extensions)
     : isolate_(isolate),
       active_(isolate->bootstrapper()) {
+  NoTrackDoubleFieldsForSerializerScope disable_double_tracking_for_serializer;
   result_ = Handle<Context>::null();
   // If V8 cannot be initialized, just return.
   if (!V8::Initialize(NULL)) return;

src/ia32/lithium-codegen-ia32.cc

@@ -3213,8 +3213,7 @@ void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
   }
 
   Register object = ToRegister(instr->object());
-  if (FLAG_track_double_fields &&
-      instr->hydrogen()->representation().IsDouble()) {
+  if (instr->hydrogen()->representation().IsDouble()) {
     if (CpuFeatures::IsSupported(SSE2)) {
       CpuFeatureScope scope(masm(), SSE2);
       XMMRegister result = ToDoubleRegister(instr->result());
@@ -4314,7 +4313,7 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
         DeoptimizeIf(zero, instr->environment());
       }
     }
-  } else if (FLAG_track_double_fields && representation.IsDouble()) {
+  } else if (representation.IsDouble()) {
     ASSERT(transition.is_null());
     ASSERT(access.IsInobject());
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());

src/mips/lithium-codegen-mips.cc

@@ -3999,7 +3999,7 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
       __ SmiTst(value, scratch);
       DeoptimizeIf(eq, instr->environment(), scratch, Operand(zero_reg));
     }
-  } else if (FLAG_track_double_fields && representation.IsDouble()) {
+  } else if (representation.IsDouble()) {
     ASSERT(transition.is_null());
     ASSERT(access.IsInobject());
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());

src/x64/lithium-codegen-x64.cc

@@ -2764,8 +2764,7 @@ void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
   }
 
   Register object = ToRegister(instr->object());
-  if (FLAG_track_double_fields &&
-      instr->hydrogen()->representation().IsDouble()) {
+  if (instr->hydrogen()->representation().IsDouble()) {
     XMMRegister result = ToDoubleRegister(instr->result());
     __ movsd(result, FieldOperand(object, offset));
     return;
@@ -3891,7 +3890,7 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
         DeoptimizeIf(cc, instr->environment());
       }
     }
-  } else if (FLAG_track_double_fields && representation.IsDouble()) {
+  } else if (representation.IsDouble()) {
     ASSERT(transition.is_null());
     ASSERT(access.IsInobject());
     ASSERT(!hinstr->NeedsWriteBarrier());