Merged from GC branch to bleeding_edge

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 66b19c8274b5a3a37671f1682b71bb1aa9fccbcc..ba9958b4ae40d53f4ab82274fca772b2b9c64237 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -295,7 +295,8 @@ void MarkCompactCollector::VerifyMarkbitsAreClean(PagedSpace* space) {
 
   while (it.has_next()) {
     Page* p = it.next();
-    ASSERT(p->markbits()->IsClean());
+    CHECK(p->markbits()->IsClean());
+    CHECK_EQ(0, p->LiveBytes());
   }
 }
 
@@ -304,7 +305,8 @@ void MarkCompactCollector::VerifyMarkbitsAreClean(NewSpace* space) {
 
   while (it.has_next()) {
     NewSpacePage* p = it.next();
-    ASSERT(p->markbits()->IsClean());
+    CHECK(p->markbits()->IsClean());
+    CHECK_EQ(0, p->LiveBytes());
   }
 }
 
@@ -402,7 +404,7 @@ bool Marking::TransferMark(Address old_start, Address new_start) {
 }
 
 
-static const char* AllocationSpaceName(AllocationSpace space) {
+const char* AllocationSpaceName(AllocationSpace space) {
   switch (space) {
     case NEW_SPACE: return "NEW_SPACE";
     case OLD_POINTER_SPACE: return "OLD_POINTER_SPACE";
@@ -2528,9 +2530,10 @@ void MarkCompactCollector::EvacuateNewSpace() {
     MarkBit mark_bit = Marking::MarkBitFrom(object);
     if (mark_bit.Get()) {
       mark_bit.Clear();
+      // Don't bother decrementing live bytes count. We'll discard the
+      // entire page at the end.
       int size = object->Size();
       survivors_size += size;
-      MemoryChunk::IncrementLiveBytes(object->address(), -size);
 
       // Aggressively promote young survivors to the old space.
       if (TryPromoteObject(object, size)) {
@@ -2621,6 +2624,7 @@ void MarkCompactCollector::EvacuateLiveObjectsFromPage(Page* p) {
     // Clear marking bits for current cell.
     cells[cell_index] = 0;
   }
+  p->ResetLiveBytes();
 }
 
 
@@ -2819,6 +2823,7 @@ static void SweepPrecisely(PagedSpace* space,
   if (free_start != p->ObjectAreaEnd()) {
     space->Free(free_start, static_cast<int>(p->ObjectAreaEnd() - free_start));
   }
+  p->ResetLiveBytes();
 }
 
 
@@ -3308,6 +3313,7 @@ intptr_t MarkCompactCollector::SweepConservatively(PagedSpace* space, Page* p) {
   if (cell_index == last_cell_index) {
     freed_bytes += static_cast<int>(space->Free(p->ObjectAreaStart(),
                                                 static_cast<int>(size)));
+    ASSERT_EQ(0, p->LiveBytes());
     return freed_bytes;
   }
   // Grow the size of the start-of-page free space a little to get up to the
@@ -3364,6 +3370,7 @@ intptr_t MarkCompactCollector::SweepConservatively(PagedSpace* space, Page* p) {
                                static_cast<int>(block_address - free_start));
   }
 
+  p->ResetLiveBytes();
   return freed_bytes;
 }