[heap] Store the host address in the typed remembered set.

src/heap/slot-set.h

Index: src/heap/slot-set.h
diff --git a/src/heap/slot-set.h b/src/heap/slot-set.h
index 1ed2b39b391cbf5c1b542e98f9d91926f6ce86d3..2fac50f9c61f4c33b7aa5874277aaef48cfca5ed 100644
--- a/src/heap/slot-set.h
+++ b/src/heap/slot-set.h
@@ -233,7 +233,30 @@ enum SlotType {
 // typed slots contain V8 internal pointers that are not directly exposed to JS.
 class TypedSlotSet {
  public:
-  typedef uint32_t TypedSlot;
+  struct TypedSlot {
+    TypedSlot() : type_and_offset_(0), host_offset_(0) {}
+
+    TypedSlot(SlotType type, uint32_t host_offset, uint32_t offset)
+        : type_and_offset_(TypeField::encode(type) |
+                           OffsetField::encode(offset)),
+          host_offset_(host_offset) {}
+
+    bool operator==(const TypedSlot other) {
+      return type_and_offset_ == other.type_and_offset_ &&
+             host_offset_ == other.host_offset_;
+    }
+
+    bool operator!=(const TypedSlot other) { return !(*this == other); }
+
+    SlotType type() { return TypeField::decode(type_and_offset_); }
+
+    uint32_t offset() { return OffsetField::decode(type_and_offset_); }
+
+    uint32_t host_offset() { return host_offset_; }
+
+    uint32_t type_and_offset_;
+    uint32_t host_offset_;
+  };
   static const int kMaxOffset = 1 << 29;
 
   explicit TypedSlotSet(Address page_start) : page_start_(page_start) {
@@ -250,8 +273,8 @@ class TypedSlotSet {
   }
 
   // The slot offset specifies a slot at address page_start_ + offset.
-  void Insert(SlotType type, int offset) {
-    TypedSlot slot = ToTypedSlot(type, offset);
+  void Insert(SlotType type, uint32_t host_offset, uint32_t offset) {
+    TypedSlot slot(type, host_offset, offset);
     if (!chunk_->AddSlot(slot)) {
       chunk_ = new Chunk(chunk_, NextCapacity(chunk_->capacity));
       bool added = chunk_->AddSlot(slot);
@@ -272,7 +295,7 @@ class TypedSlotSet {
   template <typename Callback>
   int Iterate(Callback callback) {
     STATIC_ASSERT(NUMBER_OF_SLOT_TYPES < 8);
-    const TypedSlot kRemovedSlot = TypeField::encode(NUMBER_OF_SLOT_TYPES);
+    const TypedSlot kRemovedSlot(NUMBER_OF_SLOT_TYPES, 0, 0);
     Chunk* chunk = chunk_;
     int new_count = 0;
     while (chunk != nullptr) {
@@ -281,9 +304,10 @@ class TypedSlotSet {
       for (int i = 0; i < count; i++) {
         TypedSlot slot = buffer[i];
         if (slot != kRemovedSlot) {
-          SlotType type = TypeField::decode(slot);
-          Address addr = page_start_ + OffsetField::decode(slot);
-          if (callback(type, addr) == KEEP_SLOT) {
+          SlotType type = slot.type();
+          Address addr = page_start_ + slot.offset();
+          Address host_addr = page_start_ + slot.host_offset();
+          if (callback(type, host_addr, addr) == KEEP_SLOT) {
             new_count++;
           } else {
             buffer[i] = kRemovedSlot;
@@ -303,10 +327,6 @@ class TypedSlotSet {
     return Min(kMaxBufferSize, capacity * 2);
   }
 
-  static TypedSlot ToTypedSlot(SlotType type, int offset) {
-    return TypeField::encode(type) | OffsetField::encode(offset);
-  }
-
   class OffsetField : public BitField<int, 0, 29> {};
   class TypeField : public BitField<SlotType, 29, 3> {};