Remove failure tag.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/397613002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22408 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/globals.h

@@ -216,12 +216,6 @@ const int kCodeAlignmentBits = 5;
 const intptr_t kCodeAlignment = 1 << kCodeAlignmentBits;
 const intptr_t kCodeAlignmentMask = kCodeAlignment - 1;
 
-// Tag information for Failure.
-// TODO(yangguo): remove this from space owner calculation.
-const int kFailureTag = 3;
-const int kFailureTagSize = 2;
-const intptr_t kFailureTagMask = (1 << kFailureTagSize) - 1;
-
 
 // Zap-value: The value used for zapping dead objects.
 // Should be a recognizable hex value tagged as a failure.
@@ -537,9 +531,6 @@ enum StateTag {
 #define HAS_SMI_TAG(value) \
   ((reinterpret_cast<intptr_t>(value) & kSmiTagMask) == kSmiTag)
 
-#define HAS_FAILURE_TAG(value) \
-  ((reinterpret_cast<intptr_t>(value) & kFailureTagMask) == kFailureTag)
-
 // OBJECT_POINTER_ALIGN returns the value aligned as a HeapObject pointer
 #define OBJECT_POINTER_ALIGN(value)                             \
   (((value) + kObjectAlignmentMask) & ~kObjectAlignmentMask)

src/spaces.h

@@ -312,20 +312,11 @@ class MemoryChunk {
   }
 
   Space* owner() const {
-    if ((reinterpret_cast<intptr_t>(owner_) & kFailureTagMask) ==
-        kFailureTag) {
-      return reinterpret_cast<Space*>(reinterpret_cast<intptr_t>(owner_) -
-                                      kFailureTag);
-    } else {
-      return NULL;
-    }
+    return owner_;
   }
 
   void set_owner(Space* space) {
-    ASSERT((reinterpret_cast<intptr_t>(space) & kFailureTagMask) == 0);
-    owner_ = reinterpret_cast<Address>(space) + kFailureTag;
-    ASSERT((reinterpret_cast<intptr_t>(owner_) & kFailureTagMask) ==
-           kFailureTag);
+    owner_ = space;
   }
 
   base::VirtualMemory* reserved_memory() {
@@ -691,10 +682,7 @@ class MemoryChunk {
 
   // If the chunk needs to remember its memory reservation, it is stored here.
   base::VirtualMemory reservation_;
-  // The identity of the owning space.  This is tagged as a failure pointer, but
-  // no failure can be in an object, so this can be distinguished from any entry
-  // in a fixed array.
-  Address owner_;
+  Space* owner_;
   Heap* heap_;
   // Used by the store buffer to keep track of which pages to mark scan-on-
   // scavenge.