Add support for tracking NotExectuted/ExecutedOnceCodeAge's when --track_gc_object_stats flag is se…

src/objects.cc

 // Copyright 2013 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 10601 matching lines @@
   PatchPlatformCodeAge(isolate, sequence, kNoAgeCodeAge, NO_MARKING_PARITY);
 }
 
 
 void Code::MarkCodeAsExecuted(byte* sequence, Isolate* isolate) {
   PatchPlatformCodeAge(isolate, sequence, kExecutedOnceCodeAge,
       NO_MARKING_PARITY);
 }
 
 
+static Code::Age EffectiveAge(Code::Age age) {
+  if (age == Code::kNotExecutedCodeAge) {
+    // Treat that's never been executed as old immediately.
+    age = Code::kIsOldCodeAge;
+  } else if  (age == Code::kExecutedOnceCodeAge) {

[Michael Starzinger, 2013/11/04 12:28:28]

nit: Only one white-space after "if".

[rmcilroy, 2013/11/05 13:44:57]

Done.

+    // Pre-age code that has only been executed once.
+    age = Code::kPreAgedCodeAge;
+  }
+  return age;
+}
+
+
 void Code::MakeOlder(MarkingParity current_parity) {
   byte* sequence = FindCodeAgeSequence();
   if (sequence != NULL) {
     Age age;
     MarkingParity code_parity;
     GetCodeAgeAndParity(sequence, &age, &code_parity);
+    age = EffectiveAge(age);
     if (age != kLastCodeAge && code_parity != current_parity) {
       PatchPlatformCodeAge(GetIsolate(),
                            sequence,
                            static_cast<Age>(age + 1),
                            current_parity);
     }
   }
 }
 
 
 bool Code::IsOld() {
-  Age age = GetAge();
-  return age >= kIsOldCodeAge;
+  return GetAge() >= kIsOldCodeAge;
 }
 
 
 byte* Code::FindCodeAgeSequence() {
   return FLAG_age_code &&
       prologue_offset() != Code::kPrologueOffsetNotSet &&
       (kind() == OPTIMIZED_FUNCTION ||
        (kind() == FUNCTION && !has_debug_break_slots()))
       ? instruction_start() + prologue_offset()
       : NULL;
 }
 
 
 Code::Age Code::GetAge() {
+  return EffectiveAge(GetRawAge());
+}
+
+
+Code::Age Code::GetRawAge() {
   byte* sequence = FindCodeAgeSequence();
   if (sequence == NULL) {
-    return Code::kNoAgeCodeAge;
+    return kNoAgeCodeAge;
   }
   Age age;
   MarkingParity parity;
   GetCodeAgeAndParity(sequence, &age, &parity);
   return age;
 }
 
 
 void Code::GetCodeAgeAndParity(Code* code, Age* age,
                                MarkingParity* parity) {
@@ skipping 10 matching lines @@
   stub = *builtins->Make##AGE##CodeYoungAgainOddMarking();              \
   if (code == stub) {                                                   \
     *age = k##AGE##CodeAge;                                             \
     *parity = ODD_MARKING_PARITY;                                       \
     return;                                                             \
   }
   CODE_AGE_LIST(HANDLE_CODE_AGE)
 #undef HANDLE_CODE_AGE
   stub = *builtins->MarkCodeAsExecutedOnce();
   if (code == stub) {
-    // Treat that's never been executed as old immediatly.
-    *age = kIsOldCodeAge;
+    *age = kNotExecutedCodeAge;
     *parity = NO_MARKING_PARITY;
     return;
   }
   stub = *builtins->MarkCodeAsExecutedTwice();
   if (code == stub) {
-    // Pre-age code that has only been executed once.
-    *age = kPreAgedCodeAge;
+    *age = kExecutedOnceCodeAge;
     *parity = NO_MARKING_PARITY;
     return;
   }
   UNREACHABLE();
 }
 
 
 Code* Code::GetCodeAgeStub(Isolate* isolate, Age age, MarkingParity parity) {
   Builtins* builtins = isolate->builtins();
   switch (age) {
@@ skipping 5691 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal