Remove prototype checks for leaf maps in optimized code.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 869b318f547572257b66beb0df92c9e32b2ed814..ce9f7b4c9b3483d04e2d832d4dbbe9ee0aeaf2ed 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -2294,9 +2294,9 @@ void MarkCompactCollector::ClearNonLiveReferences() {
     ClearNonLiveMapTransitions(map, map_mark);
 
     if (map_mark.Get()) {
-      ClearNonLiveDependentCodes(map);
+      ClearNonLiveDependentCode(map);
     } else {
-      ClearAndDeoptimizeDependentCodes(map);
+      ClearAndDeoptimizeDependentCode(map);
     }
   }
 }
@@ -2366,10 +2366,11 @@ void MarkCompactCollector::ClearNonLiveMapTransitions(Map* map,
 }
 
 
-void MarkCompactCollector::ClearAndDeoptimizeDependentCodes(Map* map) {
+void MarkCompactCollector::ClearAndDeoptimizeDependentCode(Map* map) {
   AssertNoAllocation no_allocation_scope;
-  DependentCodes* codes = map->dependent_codes();
-  int number_of_codes = codes->number_of_codes();
+  DependentCode* codes = map->dependent_code();
+  DependentCode::GroupStartIndexes starts(codes);
+  int number_of_codes = starts.at(DependentCode::kGroupCount);

[Michael Starzinger, 2013/02/14 12:44:04]

We should definitely add a number_of_codes() helper to GroupStartIndexes instead
of hard-coding the magic constant here.

[ulan, 2013/02/15 09:24:02]

Done.

   if (number_of_codes == 0) return;
   for (int i = 0; i < number_of_codes; i++) {
     Code* code = codes->code_at(i);
@@ -2378,31 +2379,39 @@ void MarkCompactCollector::ClearAndDeoptimizeDependentCodes(Map* map) {
     }
     codes->clear_code_at(i);
   }
-  map->set_dependent_codes(DependentCodes::cast(heap()->empty_fixed_array()));
+  map->set_dependent_code(DependentCode::cast(heap()->empty_fixed_array()));
 }
 
 
-void MarkCompactCollector::ClearNonLiveDependentCodes(Map* map) {
+void MarkCompactCollector::ClearNonLiveDependentCode(Map* map) {
   AssertNoAllocation no_allocation_scope;
-  DependentCodes* codes = map->dependent_codes();
-  int number_of_codes = codes->number_of_codes();
+  DependentCode* codes = map->dependent_code();
+  DependentCode::GroupStartIndexes starts(codes);
+  int number_of_codes = starts.at(DependentCode::kGroupCount);

[Michael Starzinger, 2013/02/14 12:44:04]

Likewise.

[ulan, 2013/02/15 09:24:02]

Done.

   if (number_of_codes == 0) return;
   int new_number_of_codes = 0;
-  for (int i = 0; i < number_of_codes; i++) {
-    Code* code = codes->code_at(i);
-    if (IsMarked(code) && !code->marked_for_deoptimization()) {
-      if (new_number_of_codes != i) {
-        codes->set_code_at(new_number_of_codes, code);
+  // Go through all groups, remove dead codes and compact.
+  for (int g = 0; g < DependentCode::kGroupCount; g++) {
+    int group_number_of_codes = 0;
+    for (int i = starts.at(g); i < starts.at(g + 1); i++) {
+      Code* code = codes->code_at(i);
+      if (IsMarked(code) && !code->marked_for_deoptimization()) {
+        if (new_number_of_codes + group_number_of_codes != i) {
+          codes->set_code_at(new_number_of_codes + group_number_of_codes, code);
+        }
+        Object** slot = codes->code_slot_at(new_number_of_codes +
+                                            group_number_of_codes);
+        RecordSlot(slot, slot, code);
+        group_number_of_codes++;
       }
-      Object** slot = codes->code_slot_at(new_number_of_codes);
-      RecordSlot(slot, slot, code);
-      new_number_of_codes++;
     }
+    codes->set_number_of_codes(static_cast<DependentCode::DependencyGroup>(g),
+                               group_number_of_codes);
+    new_number_of_codes += group_number_of_codes;
   }
   for (int i = new_number_of_codes; i < number_of_codes; i++) {
     codes->clear_code_at(i);
   }
-  codes->set_number_of_codes(new_number_of_codes);
 }