Split incremental marking write barrier into fast and slow paths.

src/incremental-marking-inl.h

 // Copyright 2011 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 19 matching lines @@
 
 #include "incremental-marking.h"
 
 namespace v8 {
 namespace internal {
 
 
 bool IncrementalMarking::BaseRecordWrite(HeapObject* obj,
                                          Object** slot,
                                          Object* value) {
-  if (IsMarking() && value->IsHeapObject()) {
-    MarkBit value_bit = Marking::MarkBitFrom(HeapObject::cast(value));
-    if (Marking::IsWhite(value_bit)) {
-      MarkBit obj_bit = Marking::MarkBitFrom(obj);
-      if (Marking::IsBlack(obj_bit)) {
-        BlackToGreyAndUnshift(obj, obj_bit);
-        RestartIfNotMarking();
-      }
+  MarkBit value_bit = Marking::MarkBitFrom(HeapObject::cast(value));
+  if (Marking::IsWhite(value_bit)) {
+    MarkBit obj_bit = Marking::MarkBitFrom(obj);
+    if (Marking::IsBlack(obj_bit)) {
+      BlackToGreyAndUnshift(obj, obj_bit);
+      RestartIfNotMarking();
+    }
 
-      // Object is either grey or white it will be scanned if survives.
-      return false;
-    }
-    return true;
+    // Object is either grey or white it will be scanned if survives.
+    return false;
   }
-  return false;
+  return true;
 }
 
 
 void IncrementalMarking::RecordWrite(HeapObject* obj,
                                      Object** slot,
                                      Object* value) {
-  if (BaseRecordWrite(obj, slot, value) && is_compacting_ && slot != NULL) {
-    MarkBit obj_bit = Marking::MarkBitFrom(obj);
-    if (Marking::IsBlack(obj_bit)) {
-      // Object is not going to be rescanned we need to record the slot.
-      heap_->mark_compact_collector()->RecordSlot(
-          HeapObject::RawField(obj, 0), slot, value);
-    }
+  if (IsMarking() && value->NonFailureIsHeapObject()) {
+    RecordWriteSlow(obj, slot, value);
   }
 }
 
 
+void IncrementalMarking::RecordWriteOfCodeEntry(JSFunction* host,
+                                                Object** slot,
+                                                Code* value) {
+  if (IsMarking()) RecordWriteOfCodeEntrySlow(host, slot, value);
+}
+
+
 void IncrementalMarking::RecordWriteIntoCode(HeapObject* obj,
                                              RelocInfo* rinfo,
                                              Object* value) {
-  if (IsMarking() && value->IsHeapObject()) {
-    MarkBit value_bit = Marking::MarkBitFrom(HeapObject::cast(value));
-    if (Marking::IsWhite(value_bit)) {
-      MarkBit obj_bit = Marking::MarkBitFrom(obj);
-      if (Marking::IsBlack(obj_bit)) {
-        BlackToGreyAndUnshift(obj, obj_bit);
-        RestartIfNotMarking();
-      }
-
-      // Object is either grey or white it will be scanned if survives.
-      return;
-    }
-
-    if (is_compacting_) {
-      MarkBit obj_bit = Marking::MarkBitFrom(obj);
-      if (Marking::IsBlack(obj_bit)) {
-        // Object is not going to be rescanned we need to record the slot.
-        heap_->mark_compact_collector()->RecordRelocSlot(rinfo,
-                                                         Code::cast(value));
-      }
-    }
+  if (IsMarking() && value->NonFailureIsHeapObject()) {
+    RecordWriteIntoCodeSlow(obj, rinfo, value);
   }
 }
 
 
 void IncrementalMarking::RecordWrites(HeapObject* obj) {
   if (IsMarking()) {
     MarkBit obj_bit = Marking::MarkBitFrom(obj);
     if (Marking::IsBlack(obj_bit)) {
       BlackToGreyAndUnshift(obj, obj_bit);
       RestartIfNotMarking();
@@ skipping 37 matching lines @@
 
 
 void IncrementalMarking::WhiteToGrey(HeapObject* obj, MarkBit mark_bit) {
   Marking::WhiteToGrey(mark_bit);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_INCREMENTAL_MARKING_INL_H_