Adapt Danno's Track Allocation Info idea to fast literals. When allocating a literal array,

src/code-stubs.h

 // Copyright 2012 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 404 matching lines @@
 
   Major MajorKey() { return FastNewBlockContext; }
   int MinorKey() { return slots_; }
 };
 
 
 class FastCloneShallowArrayStub : public PlatformCodeStub {
  public:
   // Maximum length of copied elements array.
   static const int kMaximumClonedLength = 8;
-
   enum Mode {
     CLONE_ELEMENTS,
     CLONE_DOUBLE_ELEMENTS,
     COPY_ON_WRITE_ELEMENTS,
-    CLONE_ANY_ELEMENTS
+    CLONE_ANY_ELEMENTS,
+    CLONE_ANY_ELEMENTS_WITH_ALLOCATION_INFO,

[danno, 2013/01/04 08:50:55]

CLONE_ANY_ELEMENTS_WITH_ALLOCATION_SITE_INFO?

[mvstanton, 2013/01/04 12:07:52]

Done.

+    LAST_CLONE_MODE = CLONE_ANY_ELEMENTS_WITH_ALLOCATION_INFO
   };
 
+  static const int kFastCloneModeCount = LAST_CLONE_MODE + 1;
+
+  // The stub generator likes to treat the allocation info mode separately.
+  enum AllocationInfoMode {

[danno, 2013/01/04 08:50:55]

AllocationSiteInfoMode?

[mvstanton, 2013/01/04 12:07:52]

Done.

+    DONT_TRACK_ALLOCATION_INFO,
+    TRACK_ALLOCATION_INFO
+  };

[danno, 2013/01/04 08:50:55]

Soon this will be used for other things, so I think it makes sense to move this
out of the FastCloneShallowArrayStub class. Maybe it belongs in objects.h before
the AllocationSiteInfo class itself. The constants should probably be consistent
with the class name, too, like XXX_ALLOCATION_SITE_INFO.

[mvstanton, 2013/01/04 12:07:52]

Done.

+  
   FastCloneShallowArrayStub(Mode mode, int length)
       : mode_(mode),
         length_((mode == COPY_ON_WRITE_ELEMENTS) ? 0 : length) {
     ASSERT_GE(length_, 0);
     ASSERT_LE(length_, kMaximumClonedLength);
   }
 
   void Generate(MacroAssembler* masm);
 
  private:
   Mode mode_;
   int length_;
 
   Major MajorKey() { return FastCloneShallowArray; }
   int MinorKey() {
-    ASSERT(mode_ == 0 || mode_ == 1 || mode_ == 2 || mode_ == 3);
-    return length_ * 4 +  mode_;
+    ASSERT(mode_ >= 0 && mode_ <= LAST_CLONE_MODE);
+    return length_ * kFastCloneModeCount + mode_;
   }
 };
 
 
 class FastCloneShallowObjectStub : public PlatformCodeStub {
  public:
   // Maximum number of properties in copied object.
   static const int kMaximumClonedProperties = 6;
 
   explicit FastCloneShallowObjectStub(int length) : length_(length) {
@@ skipping 838 matching lines @@
 
   // The current function entry hook.
   static FunctionEntryHook entry_hook_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileEntryHookStub);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_