Enable preaging of code objects when --optimize-for-size.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 46d65b14590035fa238674a7a2d2ef1245dfd40e..f8d6194f87952dad8d5b0b5ed98d12a4ab590f94 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -5144,11 +5144,15 @@ class Code: public HeapObject {
 
 #define DECLARE_CODE_AGE_ENUM(X) k##X##CodeAge,
   enum Age {
+    kNotExecutedCodeAge = -2,
+    kExecutedOnceCodeAge = -1,
     kNoAge = 0,
     CODE_AGE_LIST(DECLARE_CODE_AGE_ENUM)
     kAfterLastCodeAge,
     kLastCodeAge = kAfterLastCodeAge - 1,
-    kCodeAgeCount = kAfterLastCodeAge - 1
+    kCodeAgeCount = kAfterLastCodeAge - 1,
+    kPreAgedCodeAge = kQuinquagenarianCodeAge,

[danno, 2013/09/26 16:29:06]

// This is probably clearer if it is kIsOldCodeAge - 1.

[rmcilroy, 2013/09/30 19:38:43]

Done.

+    kIsOldCodeAge = kSexagenarianCodeAge
   };
 #undef DECLARE_CODE_AGE_ENUM
 
@@ -5157,10 +5161,14 @@ class Code: public HeapObject {
   // relatively safe to flush this code object and replace it with the lazy
   // compilation stub.
   static void MakeCodeAgeSequenceYoung(byte* sequence, Isolate* isolate);
+  static void MarkCodeAsExecuted(byte* sequence, Isolate* isolate);
   void MakeOlder(MarkingParity);
   static bool IsYoungSequence(byte* sequence);
   bool IsOld();
-  int GetAge();
+  Age GetAge();
+  static inline Code* GetPreAgedCodeAgeStub(Isolate* isolate) {
+    return GetCodeAgeStub(isolate, kNotExecutedCodeAge, NO_MARKING_PARITY);
+  }
 
   void PrintDeoptLocation(int bailout_id);
   bool CanDeoptAt(Address pc);