Only flush SharedFunctionInfo optimized code cache when necessary

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 9013 matching lines @@
     ASSERT(cached_literals != NULL);
     function->set_literals(cached_literals);
   }
   Code* code = Code::cast(code_map->get(index));
   ASSERT(code != NULL);
   ASSERT(function->context()->native_context() == code_map->get(index - 1));
   function->ReplaceCode(code);
 }
 
 
-void SharedFunctionInfo::ClearOptimizedCodeMap(const char* reason) {
+void SharedFunctionInfo::ClearOptimizedCodeMap(Code* optimized_code,
+                                               const char* reason) {
   if (!optimized_code_map()->IsSmi()) {
-    if (FLAG_trace_opt) {
-      PrintF("[clearing optimizing code map (%s) for ", reason);
-      ShortPrint();
-      PrintF("]\n");
+    if (optimized_code == NULL || true) {
+      if (FLAG_trace_opt) {
+        PrintF("[clearing entire optimizing code map (%s) for ", reason);
+        ShortPrint();
+        PrintF("]\n");
+      }
+      set_optimized_code_map(Smi::FromInt(0));
+    } else {
+      int i;
+      bool removed_entry = false;
+      FixedArray* code_map = FixedArray::cast(optimized_code_map());
+      for (i = 0; i < code_map->length(); i += kEntryLength) {
+        ASSERT(code_map->get(i)->IsNativeContext());
+        if (Code::cast(code_map->get(i + 1)) == optimized_code) {
+          if (FLAG_trace_opt) {
+            PrintF("[clearing optimizing code map (%s) for ", reason);
+            ShortPrint();
+            PrintF("]\n");
+          }
+          removed_entry = true;
+          break;
+        }
+      }
+      while (i < (code_map->length() - kEntryLength)) {
+        code_map->set(i, code_map->get(i + 1 + kEntryLength));
+        code_map->set(i + 1, code_map->get(i + 2 + kEntryLength));
+        code_map->set(i + 2, code_map->get(i + 3 + kEntryLength));
+        i += kEntryLength;
+      }
+      if (removed_entry) {
+        Heap* heap = GetHeap();
+        int new_length = code_map->length() - kEntryLength;
+        if (new_length == 0) {
+          set_optimized_code_map(Smi::FromInt(0));
+          return;
+        }
+        Address filler_start = reinterpret_cast<Address>(
+            code_map->GetFirstElementAddress() + new_length);
+        heap->CreateFillerObjectAt(filler_start,
+                                   kEntryLength * kPointerSize);
+        code_map->set_length(new_length);
+      }
     }
-    set_optimized_code_map(Smi::FromInt(0));
   }
 }
 
 
 bool JSFunction::CompileLazy(Handle<JSFunction> function,
                              ClearExceptionFlag flag) {
   bool result = true;
   if (function->shared()->is_compiled()) {
     function->ReplaceCode(function->shared()->code());
     function->shared()->set_code_age(0);
@@ skipping 6302 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal