Incremental mode now works for x64. The only difference

src/spaces.h

Index: src/spaces.h
===================================================================
--- src/spaces.h	(revision 8221)
+++ src/spaces.h	(working copy)
@@ -170,6 +170,8 @@
   static const uint32_t kBitsPerCell = 32;

[Lasse Reichstein, 2011/06/10 13:55:44]

kBitsPerInt ?

[Erik Corry, 2011/06/10 21:57:29]

Not really.

   static const uint32_t kBitsPerCellLog2 = 5;
   static const uint32_t kBitIndexMask = kBitsPerCell - 1;
+  static const uint32_t kBytesPerCell = kBitsPerCell / 8;

[Lasse Reichstein, 2011/06/10 13:55:44]

8 -> kBitsPerByte

[Erik Corry, 2011/06/10 21:57:29]

Done.

+  static const uint32_t kBytesPerCellLog2 = kBitsPerCellLog2 - 3;

[Lasse Reichstein, 2011/06/10 13:55:44]

3 -> kBitesPerByteLog2

[Erik Corry, 2011/06/10 21:57:29]

Done.

 
   static const size_t kLength =
     (1 << kPageSizeBits) >> (kPointerSizeLog2);
@@ -653,6 +655,14 @@
   // (e.g. see LargeObjectSpace).
   virtual intptr_t SizeOfObjects() { return Size(); }
 
+  virtual int RoundSizeDownToObjectAlignment(int size) {
+    if (id_ == CODE_SPACE) {
+      return RoundDown(size, kCodeAlignment);
+    } else {
+      return RoundDown(size, kPointerSize);
+    }
+  }
+
 #ifdef ENABLE_HEAP_PROTECTION
   // Protect/unprotect the space by marking it read-only/writable.
   virtual void Protect() = 0;
@@ -2201,6 +2211,14 @@
     return false;  // TODO(gc): Bring back map compaction.
   }
 
+  virtual int RoundSizeDownToObjectAlignment(int size) {
+    if (IsPowerOf2(Map::kSize)) {
+      return RoundDown(size, Map::kSize);
+    } else {
+      return (size / Map::kSize) * Map::kSize;
+    }
+  }
+
  protected:
 #ifdef DEBUG
   virtual void VerifyObject(HeapObject* obj);
@@ -2231,6 +2249,14 @@
       : FixedSpace(heap, max_capacity, id, JSGlobalPropertyCell::kSize, "cell")
   {}
 
+  virtual int RoundSizeDownToObjectAlignment(int size) {
+    if (IsPowerOf2(JSGlobalPropertyCell::kSize)) {
+      return RoundDown(size, JSGlobalPropertyCell::kSize);
+    } else {
+      return (size / JSGlobalPropertyCell::kSize) * JSGlobalPropertyCell::kSize;
+    }
+  }
+
  protected:
 #ifdef DEBUG
   virtual void VerifyObject(HeapObject* obj);